Search Results: "ema"

20 May 2026

Michael Prokop: The mysterious XF86AudioPlay issue

I was getting <XF86AudioPlay> is undefined in the status bar of Emacs displayed every 2-3 seconds. Nowhere else I noticed any misbehavior or problems, and also couldn t find any related log entries. It didn t stop, though didn t want to reboot my system to see whether that would fix the problem, but it was driving me nuts. Now, as a starting point I adjusted my sway configuration, to react to the XF86AudioPlay key press event:
bindsym XF86AudioPlay exec playerctl play-pause
After reloading sway, my music player started to play for 2-3 seconds, stopped playing, started again, etc. It wasn t a Emacs bug, but something indeed seemed to send the XF86AudioPlay key event every 2-3 seconds. It wasn t my USB keyboard or any stuck key on it, as verified also by unplugging it. So which device was causing this? libinput from libinput-tools to the rescue:
% sudo libinput debug-events
[...]
-event12  KEYBOARD_KEY                 +0.000s  KEY_PLAYPAUSE (164) pressed
 event12  KEYBOARD_KEY                 +0.000s  KEY_PLAYPAUSE (164) released
 event12  KEYBOARD_KEY                 +2.887s  KEY_PLAYPAUSE (164) pressed
 event12  KEYBOARD_KEY                 +2.887s  KEY_PLAYPAUSE (164) released
 event12  KEYBOARD_KEY                 +5.773s  KEY_PLAYPAUSE (164) pressed
 event12  KEYBOARD_KEY                 +5.774s  KEY_PLAYPAUSE (164) released
[...]
The event12 device was sending this event, what s behind this?
% sudo udevadm info /dev/input/event12
P: /devices/pci0000:00/0000:00:1f.3/skl_hda_dsp_generic/sound/card0/input17/event12
M: event12
R: 12
J: c13:76
U: input
D: c 13:76
N: input/event12
L: 0
S: input/by-path/pci-0000:00:1f.3-platform-skl_hda_dsp_generic-event
E: DEVPATH=/devices/pci0000:00/0000:00:1f.3/skl_hda_dsp_generic/sound/card0/input17/event12
E: DEVNAME=/dev/input/event12
E: MAJOR=13
E: MINOR=76
E: SUBSYSTEM=input
E: USEC_INITIALIZED=12468722
E: ID_INPUT=1
E: ID_INPUT_KEY=1
E: ID_INPUT_SWITCH=1
E: ID_PATH=pci-0000:00:1f.3-platform-skl_hda_dsp_generic
E: ID_PATH_TAG=pci-0000_00_1f_3-platform-skl_hda_dsp_generic
E: XKBMODEL=pc105
E: XKBLAYOUT=us
E: XKBOPTIONS=lv3:ralt_switch,compose:rctrl
E: BACKSPACE=guess
E: LIBINPUT_DEVICE_GROUP=0/0/0:ALSA
E: DEVLINKS=/dev/input/by-path/pci-0000:00:1f.3-platform-skl_hda_dsp_generic-event
E: TAGS=:power-switch:
E: CURRENT_TAGS=:power-switch:
% sudo udevadm info -a /dev/input/event12   grep -iE 'kernels drivers name'
    KERNELS=="input17"
    DRIVERS==""
    ATTRS name =="sof-hda-dsp Headphone"
    KERNELS=="card0"
    DRIVERS==""
    KERNELS=="skl_hda_dsp_generic"
    DRIVERS=="skl_hda_dsp_generic"
    KERNELS=="0000:00:1f.3"
    DRIVERS=="sof-audio-pci-intel-tgl"
    KERNELS=="pci0000:00"
    DRIVERS==""
Behind this event12 is sof-hda-dsp Headphone, and evtest confirms that:
% sudo evtest
No device specified, trying to scan all of /dev/input/event*
Available devices:
/dev/input/event0:      AT Translated Set 2 keyboard
/dev/input/event1:      Sleep Button
/dev/input/event10:     ThinkPad Extra Buttons
/dev/input/event11:     sof-hda-dsp Mic
/dev/input/event12:     sof-hda-dsp Headphone
/dev/input/event13:     sof-hda-dsp HDMI/DP,pcm=3
/dev/input/event14:     sof-hda-dsp HDMI/DP,pcm=4
/dev/input/event15:     sof-hda-dsp HDMI/DP,pcm=5
/dev/input/event16:     Yubico YubiKey OTP+FIDO+CCID
/dev/input/event17:     Apple Inc. Magic Keyboard with Numeric Keypad
/dev/input/event18:     Apple Inc. Magic Keyboard with Numeric Keypad
[...]
Select the device event number [0-24]: ^C
We can even get further information:
% sudo evtest /dev/input/event12
Input driver version is 1.0.1
Input device ID: bus 0x0 vendor 0x0 product 0x0 version 0x0
Input device name: "sof-hda-dsp Headphone"
Supported events:
  Event type 0 (EV_SYN)
  Event type 1 (EV_KEY)
    Event code 114 (KEY_VOLUMEDOWN)
    Event code 115 (KEY_VOLUMEUP)
    Event code 164 (KEY_PLAYPAUSE)
    Event code 582 (KEY_VOICECOMMAND)
  Event type 5 (EV_SW)
    Event code 2 (SW_HEADPHONE_INSERT) state 0
Properties:
Testing ... (interrupt to exit)
Event: time 1779295060.175766, type 5 (EV_SW), code 2 (SW_HEADPHONE_INSERT), value 1
Event: time 1779295060.175766, -------------- SYN_REPORT ------------
Event: time 1779295061.951168, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 1
Event: time 1779295061.951168, -------------- SYN_REPORT ------------
Event: time 1779295061.951194, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 0
Event: time 1779295061.951194, -------------- SYN_REPORT ------------
Event: time 1779295064.548671, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 1
Event: time 1779295064.548671, -------------- SYN_REPORT ------------
Event: time 1779295064.548689, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 0
Event: time 1779295064.548689, -------------- SYN_REPORT ------------
Event: time 1779295067.437172, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 1
Event: time 1779295067.437172, -------------- SYN_REPORT ------------
Event: time 1779295067.437187, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 0
Event: time 1779295067.437187, -------------- SYN_REPORT ------------
Event: time 1779295070.323775, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 1
Event: time 1779295070.323775, -------------- SYN_REPORT ------------
Event: time 1779295070.323790, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 0
Event: time 1779295070.323790, -------------- SYN_REPORT ------------
Event: time 1779295073.200350, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 1
Event: time 1779295073.200350, -------------- SYN_REPORT ------------
Event: time 1779295073.200373, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 0
Event: time 1779295073.200373, -------------- SYN_REPORT ------------
Event: time 1779295076.076228, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 1
Event: time 1779295076.076228, -------------- SYN_REPORT ------------
Event: time 1779295076.076250, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 0
Event: time 1779295076.076250, -------------- SYN_REPORT ------------
Event: time 1779295078.961740, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 1
Event: time 1779295078.961740, -------------- SYN_REPORT ------------
Event: time 1779295078.961754, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 0
Event: time 1779295078.961754, -------------- SYN_REPORT ------------
Event: time 1779295081.850156, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 1
Event: time 1779295081.850156, -------------- SYN_REPORT ------------
Event: time 1779295081.850175, type 1 (EV_KEY), code 164 (KEY_PLAYPAUSE), value 0
Event: time 1779295081.850175, -------------- SYN_REPORT ------------
Event: time 1779295083.306612, type 5 (EV_SW), code 2 (SW_HEADPHONE_INSERT), value 0
Event: time 1779295083.306612, -------------- SYN_REPORT ------------
So when I plug in my headphone (see the SW_HEADPHONE_INSERT event), the unexpected behavior starts, unplugging stops the problem.
Good! But what was totally unexpected for me: my headphone, being a Beyerdynamic DT-990 Pro, does not have any keys. 8-) As it turned out, the headphone jack seemed to have been not entirely clean. The analog side of the jack triggers a behavior within the audio codec, where it seems to interpret the fluctuating impedance as a play button of the headset, being pressed, again and again. I cleaned the jack of my headphone and my XF86AudioPlay problem is gone, case closed.

Tianon Gravi: Containers Are a Security Boundary (some assembly required)

I've heard "containers are not a security boundary" enough times that it's started to feel like received wisdom, and my honest read (after 13+ years) is that it's technically defensible but practically sloppy and the sloppiness matters. The part that's true: containers share a kernel, and a kernel exploit crosses the container boundary where a VM would not. That difference is real and non-trivial, and the CVE history backs it up CVE-2019-5736, CVE-2022-0492, and CVE-2024-21626 all happened in "correctly configured" production containers. The part I'd push back on is that the comparison point is almost never stated. "Containers aren't a security boundary" is being used as shorthand for "containers aren't a VM boundary" but the conclusion people seem to draw from that is "therefore don't bother", which doesn't actually follow. The more honest version is that default Docker doesn't provide strong isolation between mutually untrusting parties, but a hardened configuration does. What ships by default in Moby is actually a pretty reasonable foundation: seccomp is enabled (with a builtin profile blocking ~50 syscalls credit where it's due: this is mostly @jessfraz's work; she even ran contained.af as a public CTF for years daring people to escape a container under her seccomp profile, and to my knowledge it was never claimed), AppArmor is enabled (the docker-default profile), and several sensitive /proc paths are masked. What's not on by default: no-new-privileges (setuid binaries inside can escalate), CAP_NET_RAW is still granted to every container (even though the kernel has supported unprivileged ICMP sockets for over a decade, meaning most modern distributions no longer need CAP_NET_RAW for ping), and user namespace remapping though user namespaces aren't quite the silver bullet they might sound like; Debian left them disabled by default for years because the kernel attack surface they exposed hadn't been hardened against unprivileged callers. The boundary isn't absent it doesn't come completely pre-assembled. With VMs, the hypervisor is there whether you asked for it or not; with containers, assembling the boundary is left as an exercise for the operator. That's a much more solvable problem than "the technology is incapable", but it does mean the work falls to whoever's running the containers. So, some things you can do today without waiting for defaults to change: --user (or USER in your Dockerfile) is worth calling out specifically, because I think it's arguably stronger than user namespace remapping in one important way and partly for the same reason Debian was hesitant about user namespaces in the first place. User namespace remapping protects the host from a root-in-container escape: if you do escape, you land as an unprivileged user on the host. But you were still root inside the container the whole time. Running as a non-root user means you were never root anywhere. The blast radius of a compromised process is limited whether or not it escapes, including for things like reading secrets, modifying container contents, or lateral movement within the container itself. Most application containers have no legitimate reason to be root. Beyond that, a short list of things that are easy to enable and hard to justify leaving off:
docker run \
  --user 1234:5678 \
  --security-opt no-new-privileges \
  --read-only \
  --tmpfs /tmp \
  --cap-drop ALL \
  acme/untrusted-workload:latest
None of these require a daemon restart or infrastructure changes, and stacked together they go a long way toward actually building the boundary that the defaults leave unbuilt. (this post was written with the assistance of "claude my eyes right out" but all thoughts and understanding are Tianon's)

18 May 2026

Sergio Durigan Junior: Fixing a 20+ year old bug in Debian curl

I have been helping co-maintain the Debian curl package for a few years now, and even though Samuel and Charles do most of the work, I'm happy to jump in and help when needed. This is one of those cases. Nowadays the package is maintained by 3 people (with help from others occasionally), but it hasn't always been like this. Samuel adopted the package back in 2021, and since then it has received a lot of love and care to make sure it lives up to Debian's standards. Again, kudos to both him and Charles who have been doing great work on this front. But a little more than 20 years ago, the situation in Debian (and curl!) was "a bit" different.

Once upon a time... According to d/changelog, the Debian curl maintainer in 2005 introduced changes to the packaging that allowed it to generate a version of libcurl for each TLS backend available: OpenSSL and GnuTLS. This meant that curl would have two binary library packages:
  • libcurl3-openssl and its respective -dev variant, for libcurl linked against OpenSSL; and
  • libcurl3-gnutls and its respective -dev variant, for libcurl linked against GnuTLS.
But then, around 2006/2007 or so, upstream curl decided to bump the SONAME version of libcurl from 3 to 4. At the time, they apparently did not version their library symbols like they do now, which was... less than ideal. I don't judge them: curl and a lot of other important projects have come a long way when we consider best practices to write shared libraries. Meanwhile, on Debian land, the release team was having trouble with other transitions going on at the time. For those who are not versed in Debian's vocabulary, a transition happens when a shared library gets its SONAME version bumped: when this happens, we have to make sure that all reverse dependencies of that library still build with the new version, and fix things that fail. The more reverse dependencies the library has, the harder this work gets. When upstream curl bumping the SONAME version of libcurl, the Debian curl maintainer at the time correctly renamed the binary packages from libcurl3- openssl,gnutls (and their -dev variants) to libcurl4- openssl,gnutls (and their -dev variants), which obviously triggered a transition. And a big one, because libcurl is used by several projects. Long story short, the Debian release team found themselves between a rock and a hard place. According to the late Steve Langasek at the time:
We talked a while back about the curl transition, and about how upstream's change from libcurl.so.3 to libcurl.so.4 is gratuitously painful for us in light of the large number of reverse dependencies. The libcurl transition has at this point gotten tangled with soname transitions in jasper, exiv2, kexiv2, and God only knows what else. So I'd like to revisit this question, because tracking this transition is costing the release team a lot of time that would be better spent elsewhere, and removing the need for a libcurl transition promises to reduce the complexity of the other components by an order of magnitude. On looking at the curl package, I've come to understand that the symbol versioning in place in this library is the result of a Debian-local patch. That's great news, because it suggests a solution to this quandary that doesn't require an unreasonable amount of developer time.
Yeah, it wasn't pretty. Here's what was proposed:
I am proposing the following:
  • Keep the library soname the same as it currently is upstream. Because upstream uses unversioned symbols, our package will be binary-compatible with applications built against the upstream libcurl regardless of what we do with symbol versioning, so leaving the soname alone minimizes the amount of patching to be done against upstream code here.
  • Revert the Debian symbol versioning to the libcurl3 version, and make libcurl.so.3 a symlink to libcurl.so.4. We have already established that libcurl.so.4 is still API-compatible with libcurl.so.3, in spite of the soname change upstream; reverting the symbol versioning will make it fully ABI-compatible with libcurl.so.3, and adding the symlink lets previously-built binaries find it.
  • Revert the Debian package names to the curl 7.15.5 versions. Because compatibility has been restored with libcurl3 and libcurl3-gnutls, restoring the package names provides the best upgrade path from etch to lenny; and because the symbol versions have been reverted, the libraries are not binary-compatible with the Debian packages currently named libcurl4/libcurl4-gnutls/libcurl4-openssl (in spite of being binary-compatible with upstream), so it would be wrong to keep the current names regardless.
  • Drop the SSL-less variant of the library, which was not present in curl 7.15.5; AFAICS, there is no use case where a user of curl needs to not have SSL support, so this split seems to be unnecessary overhead. Please correct me if I'm mistaken.
  • Leave the -dev package names alone otherwise, to simplify binNMUing of the reverse-dependencies (some packages have already added versioned build-deps on libcurl4.*-dev -- I have no idea why -- so reverting the names would mean more work to chase down those packages). Drop libcurl4-dev as a binary package, though, in favor of being Provided by libcurl4-gnutls-dev. Many of the packages currently build-depending on libcurl4-dev -- including some that wrongly used libcurl3-dev before -- are GPL, and these are apparently all packages where having SSL support missing in libcurl4 wasn't hurting them, so libcurl4-gnutls-dev seems to be the reasonable "default" here.
  • Schedule binNMUs for all reverse-dependencies.
Again, no judgement here: this was what needed to be done at the time, and I believe it was a good solution given the circumstances. In the end, the binary library packages got renamed again: from libcurl4- openssl,gnutls back to libcurl3- openssl,gnutls (but not their -dev variants!), but they continued shipping libcurl libraries whose SONAME version was 4. This solved the immediate problem of untangling the transitions mentioned by Steve, but introduced a technical debt that would stick with the package literally for decades. The situation at the end of 2007 was:
  • libcurl3-openssl with libcurl4-openssl-dev; and
  • libcurl3-gnutls with libcurl4-gnutls-dev.

More discrepancy is added Eventually the libcurl3-openssl package got renamed to libcurl3, but aside from that the situation with mismatched library names vs. SONAME versions stayed relatively unchanged until around 2018, when the Debian curl maintainer at the time (a different person) renamed libcurl3 to libcurl4 to fix a bug. This was the right thing to do for libcurl3, and at the time upstream curl was already properly versioning their symbols, but for some reason libcurl3-gnutls got left behind. So now we had:
  • libcurl4 with libcurl4-dev; and
  • libcurl3-gnutls with libcurl4-gnutls-dev.
In other words, we now have a discrepancy between the OpenSSL and GnuTLS variants' names. Yeah, confusing. And this is the situation right now, on May 2026, while I write this post. To make matters worse, the Debian curl package has been carrying a patch to facilitate the split of OpenSSL and GnuTLS flavours for decades now, and, for some reason I didn't bother to investigate, the patch pins the SONAME version of libcurl3-gnutls to CURL_GNUTLS_3, effectively overriding upstream's decision to version the symbols as CURL_GNUTLS_4.

A call to make things right Back in 2022, Simon McVittie filed a Debian bug to try and call our attention to the fact that we were shipping this messy set of curl packages. I had just started to get involved in the package maintenance and Samuel asked me to take a look at the bug. I noticed it was going to take more time than I had available, so I decided to put it in my TODO list (TM). Simon was generous enough to lay out a possible plan to tackle the problem, but I had a feeling that this was going to be harder than it looked. I kept postponing working on the bug, but also kept thinking about it now and then because it's an interesting thing to solve. Then, a month or so ago the Debian Brasil community got together for MiniDebConf Campinas 2026 and we decided to do a bug squashing party there. I started working on a few FTBFS bugs with GCC 16, but then got remembered about the curl bug and thought that that was the perfect time and place to start working on it, for a few reasons:
  • Samuel and Charles were also attending the conference, so I could talk to them about my plans and show them a PoC.
  • I was going to give a presentation about symbols (in pt_BR), so I could use this bug as an example of symbol versioning.
  • I wanted to have fun.

The initial plan The plan I had in mind was a variant of Simon's proposed plan:
  • I would have to adjust our GnuTLS-specific patch so that it did not override the SONAME version for libcurl-gnutls. Then,
  • For each symbol from libcurl3-gnutls I would have to:
    • Explicitly version it as curl_symbol_name@@CURL_GNUTLS_4.
    • Create an alias for the symbol (let's call it __curl_compat_symbol_name).
    • Explicitly version this alias as __curl_compat_symbol_name@CURL_GNUTLS_3.
  • Have a separate version of curl's linker script to make it possible to create a hierarchy between CURL_GNUTLS_3 and CURL_GNUTLS_4 symbols.
Note that this whole dance is needed because it is a hard requirement that programs linked against libcurl3-gnutls keep working when we ship libcurl4-gnutls, without needing to recompile them. Due to the fact that we will not really bump the SONAME of libcurl-gnutls (but instead fix the symbol versions shipped by it), we cannot expect programs to break given that they are actually using the exact same ABI as before. Unfortunately (as it is common with low level tools) the documentation for ld's versioning syntax is quite incomplete and hard to find. One of the best sources I found was this blog post. For this reason, let me quickly explain the different notations for symbol versioning used above.

curl_symbol_name@@CURL_GNUTLS_4 When we use curl_symbol_name@@CURL_GNUTLS_4 (note the @@) we are telling the linker that this should be considered the default version of curl_symbol_name. In other words, when a binary that links against libcurl-gnutls calls curl_symbol_name, the linker should use curl_symbol_name@@CURL_GNUTLS_4 to resolve the symbol. There are a few ways to specify a symbol version in C/C++:
__attribute__((__symver__("curl_symbol_name@@CURL_GNUTLS_4")))
void curl_symbol_name()
 
  /* ... */
 

/* or... */
void curl_symbol_name()
 
  /* ... */
 
__asm__(".symver curl_symbol_name, curl_symbol_name@@CURL_GNUTLS_4");

Function alias Creating an alias for a function is basically saying that a function can be called by another name. You can do that in C/C++ like:
void curl_symbol_name()
 
  /* ... */
 

void __curl_compat_symbol_name()
  __attribute__((alias("curl_symbol_name")));

__curl_compat_symbol_name@CURL_GNUTLS_3 Finally, when we use __curl_compat_symbol_name@CURL_GNUTL_3 (note the single @) we are telling the linker that this symbol exists, but it should not be used as the default symbol. In fact, this notation will basically hide the symbol and make it only available for those programs that have already been linked against it. It's a way of saying "don't offer this symbol when linking, but it's here in case a program needs it to run" (it's a bit more complicated than that, but you get the point). The reason I had to create an alias to the function before versioning the symbol with @CURL_GNUTLS_3 is because, once I've versioned the main symbol as @@CURL_GNUTLS_4, I can't create another version of it. It's also important to mention that to be able to create a version for the alias I also had to change its visibility to default. In the end, the alias ended up being defined as:
extern void __curl_compat_symbol_name()
  __attribute__((alias("curl_symbol_name"), visibility("default")));

First attempt and lessons learned For my PoC I decided to tackle a small subset of the problem. The symbols file for libcurl3-gnutls contains around 100 symbols that need to be fixed, so I chose two of them and started trying to write a patch to see if I could make things work. And after some time struggling with GCC's syntax and inspecting nm -D's output I finally got something that looked like it was going to work. The two symbols I had chosen to work with got correctly versioned (both as @@CURL_GNUTLS_4 and @CURL_GNUTLS_3), and a quick-and-dirty C program that used those symbols correctly compiled and ran with the expected symbols. I showed the results to Samuel and Charles, we got excited about what we saw, and then the conference ended.

Second attempt and some adjustments After getting back home I resumed the work on my branch and wrote an Emacs function that semi-automatically adjusted all 100+ symbols listed in the symbols file so that they all looked like:
__attribute__((__symver__("curl_symbol_name@@CURL_GNUTLS_4")))
void curl_symbol_name()
 
  /* ... */
 

extern void __curl_compat_symbol_name()
  __attribute__((alias("curl_symbol_name"), visibility("default"),
                 symver("__curl_compat_symbol_name@CURL_GNUTLS_3")));
The patch was big but mostly repetitive, and I was happy to have come up with a solution that looked clean. Until I tried to build the package, that is. I started seeing some strange errors that happened when ld was trying to link the final libcurl4-gnutls object (yes, at that point I had already renamed the binary package). This is one of the errors I was getting from ld (I got variants of this error as I was trying to fix the approach):
/usr/bin/x86_64-linux-gnu-ld.bfd: .libs/libcurl_gnutls_la-easy.o: in function  dupeasy_meta_freeentry':
./debian/build-gnutls/lib/./debian/build-gnutls/lib/easy.c:1024: multiple definition of  curl_easy_cleanup'; .libs/libcurl_gnutls_la-easy.o:./debian/build-gnutls/lib/./debian/build-gnutls/lib/easy.c:908: first defined here
/usr/bin/x86_64-linux-gnu-ld.bfd: .libs/libcurl-gnutls.so.4.8.0: version node not found for symbol curl_easy_duphandle@CURL_GNUTLS3
/usr/bin/x86_64-linux-gnu-ld.bfd: failed to set dynamic section sizes: bad value
This was strange. I did some tests with very simple versions of a shared library using the versioning mechanism I had implemented and it all worked. I could not reproduce the problem, and that's not a great feeling to have. Then, after reading a lot of documentation and blog posts throughout the internet I found something interesting. Apparently ld has a limitation when it comes to dealing with symbols versioned with @@. If there is a single symbol versioned like that in a source file (the actual term is TU, which means Translation Unit, but let's simplify), then ld is happy and generates the expected version without issues. But when we're dealing with multiple definitions of @@ symbols in a source file (which is exactly what happens in curl), then ld can get confused and start giving errors during the link stage. To solve that limitation, we have to resort to yet another symbol versioning notation: @@@. Yes, three at signs. For example:
void curl_symbol_name()
 
  /* ... */
 
__asm__(".symver curl_symbol_name, curl_symbol_name@@@CURL_GNUTLS_4");
Note that we have to use __asm__ because GCC's __attribute__ doesn't support the triple-at notation. What this does is tell the linker to create a versioned symbol for curl_symbol_name, set it as the default symbol when linking, but also remove the unversioned curl_symbol_name symbol. This makes ld happy and allows it to successfully link libcurl-gnutls. As usual, you won't find any mention of the @@@ notation inside ld's documentation. With libcurl-gnutls compiling again, I had to adjust libcurl's linker script to create a hierarchy between CURL_GNUTLS_3 and CURL_GNUTLS_4 symbols. Here's the final version of the file:
CURL_GNUTLS_3
 
  global:
    curl_easy_cleanup;
    /* lots of other symbols here */
  local: *;
 ;

CURL_GNUTLS_4
 
  global: curl_*;
  local: *;
  CURL_GNUTLS_3;

Debian package adjustments After getting the hard part out of the way, the rest was easy. It was time to finally rename libcurl3-gnutls to libcurl4-gnutls. Initially I was thinking that I'd need to ask the release team for a transition to happen, but as it turns out that won't be necessary. Because we are effectively shipping the same exact library/ABI and the only difference is the inclusion of the extra CURL_GNUTLS_4 versioned symbols, and given that we will be shipping CURL_GNUTLS_3 versioned symbols to guarantee backwards compatibility, packages won't need to get rebuild just to pick up the new dependency. Instead, we can safely turn libcurl3-gnutls into a transitional package that depends on libcurl4-gnutls.

Merge request and next steps This is the merge request where I am working on the fix. As of this writing it is in a draft state, but I expect to merge in the next couple of days. Once the fixed curl package is uploaded, we should keep an eye on the archive to make sure no unexpected bugs happen. I would like to carry this patch downstream at least until forky is released. It doesn't make sense to propose it upstream because this problem is Debian-specific and should be fixed there. We will need to make sure that all reverse dependencies of libcurl3-gnutls are recompiled before we can get rid of the transitional package, too. This was a fun bug to investigate and fix, and I am happy that we will finally have sensible names (and symbol versions!) for both of our libcurl variants. Stay tuned for the next challenge!

Sergio Durigan Junior: Fixing a 20+ year old bug in Debian curl

I have been helping co-maintain the Debian curl package for a few years now, and even though Samuel and Charles do most of the work, I'm happy to jump in and help when needed. This is one of those cases. Nowadays the package is maintained by 3 people (with help from others occasionally), but it hasn't always been like this. Samuel adopted the package back in 2021, and since then it has received a lot of love and care to make sure it lives up to Debian's standards. Again, kudos to both him and Charles who have been doing great work on this front. But a little more than 20 years ago, the situation in Debian (and curl!) was "a bit" different.

Once upon a time... According to d/changelog, the Debian curl maintainer in 2005 introduced changes to the packaging that allowed it to generate a version of libcurl for each TLS backend available: OpenSSL and GnuTLS. This meant that curl would have two binary library packages:
  • libcurl3-openssl and its respective -dev variant, for libcurl linked against OpenSSL; and
  • libcurl3-gnutls and its respective -dev variant, for libcurl linked against GnuTLS.
But then, around 2006/2007 or so, upstream curl decided to bump the SONAME version of libcurl from 3 to 4. At the time, they apparently did not version their library symbols like they do now, which was... less than ideal. I don't judge them: curl and a lot of other important projects have come a long way when we consider best practices to write shared libraries. Meanwhile, on Debian land, the release team was having trouble with other transitions going on at the time. For those who are not versed in Debian's vocabulary, a transition happens when a shared library gets its SONAME version bumped: when this happens, we have to make sure that all reverse dependencies of that library still build with the new version, and fix things that fail. The more reverse dependencies the library has, the harder this work gets. When upstream curl bumping the SONAME version of libcurl, the Debian curl maintainer at the time correctly renamed the binary packages from libcurl3- openssl,gnutls (and their -dev variants) to libcurl4- openssl,gnutls (and their -dev variants), which obviously triggered a transition. And a big one, because libcurl is used by several projects. Long story short, the Debian release team found themselves between a rock and a hard place. According to the late Steve Langasek at the time:
We talked a while back about the curl transition, and about how upstream's change from libcurl.so.3 to libcurl.so.4 is gratuitously painful for us in light of the large number of reverse dependencies. The libcurl transition has at this point gotten tangled with soname transitions in jasper, exiv2, kexiv2, and God only knows what else. So I'd like to revisit this question, because tracking this transition is costing the release team a lot of time that would be better spent elsewhere, and removing the need for a libcurl transition promises to reduce the complexity of the other components by an order of magnitude. On looking at the curl package, I've come to understand that the symbol versioning in place in this library is the result of a Debian-local patch. That's great news, because it suggests a solution to this quandary that doesn't require an unreasonable amount of developer time.
Yeah, it wasn't pretty. Here's what was proposed:
I am proposing the following:
  • Keep the library soname the same as it currently is upstream. Because upstream uses unversioned symbols, our package will be binary-compatible with applications built against the upstream libcurl regardless of what we do with symbol versioning, so leaving the soname alone minimizes the amount of patching to be done against upstream code here.
  • Revert the Debian symbol versioning to the libcurl3 version, and make libcurl.so.3 a symlink to libcurl.so.4. We have already established that libcurl.so.4 is still API-compatible with libcurl.so.3, in spite of the soname change upstream; reverting the symbol versioning will make it fully ABI-compatible with libcurl.so.3, and adding the symlink lets previously-built binaries find it.
  • Revert the Debian package names to the curl 7.15.5 versions. Because compatibility has been restored with libcurl3 and libcurl3-gnutls, restoring the package names provides the best upgrade path from etch to lenny; and because the symbol versions have been reverted, the libraries are not binary-compatible with the Debian packages currently named libcurl4/libcurl4-gnutls/libcurl4-openssl (in spite of being binary-compatible with upstream), so it would be wrong to keep the current names regardless.
  • Drop the SSL-less variant of the library, which was not present in curl 7.15.5; AFAICS, there is no use case where a user of curl needs to not have SSL support, so this split seems to be unnecessary overhead. Please correct me if I'm mistaken.
  • Leave the -dev package names alone otherwise, to simplify binNMUing of the reverse-dependencies (some packages have already added versioned build-deps on libcurl4.*-dev -- I have no idea why -- so reverting the names would mean more work to chase down those packages). Drop libcurl4-dev as a binary package, though, in favor of being Provided by libcurl4-gnutls-dev. Many of the packages currently build-depending on libcurl4-dev -- including some that wrongly used libcurl3-dev before -- are GPL, and these are apparently all packages where having SSL support missing in libcurl4 wasn't hurting them, so libcurl4-gnutls-dev seems to be the reasonable "default" here.
  • Schedule binNMUs for all reverse-dependencies.
Again, no judgement here: this was what needed to be done at the time, and I believe it was a good solution given the circumstances. In the end, the binary library packages got renamed again: from libcurl4- openssl,gnutls back to libcurl3- openssl,gnutls (but not their -dev variants!), but they continued shipping libcurl libraries whose SONAME version was 4. This solved the immediate problem of untangling the transitions mentioned by Steve, but introduced a technical debt that would stick with the package literally for decades. The situation at the end of 2007 was:
  • libcurl3-openssl with libcurl4-openssl-dev; and
  • libcurl3-gnutls with libcurl4-gnutls-dev.

More discrepancy is added Eventually the libcurl3-openssl package got renamed to libcurl3, but aside from that the situation with mismatched library names vs. SONAME versions stayed relatively unchanged until around 2018, when the Debian curl maintainer at the time (a different person) renamed libcurl3 to libcurl4 to fix a bug. This was the right thing to do for libcurl3, and at the time upstream curl was already properly versioning their symbols, but for some reason libcurl3-gnutls got left behind. So now we had:
  • libcurl4 with libcurl4-dev; and
  • libcurl3-gnutls with libcurl4-gnutls-dev.
In other words, we now have a discrepancy between the OpenSSL and GnuTLS variants' names. Yeah, confusing. And this is the situation right now, on May 2026, while I write this post. To make matters worse, the Debian curl package has been carrying a patch to facilitate the split of OpenSSL and GnuTLS flavours for decades now, and, for some reason I didn't bother to investigate, the patch pins the SONAME version of libcurl3-gnutls to CURL_GNUTLS_3, effectively overriding upstream's decision to version the symbols as CURL_GNUTLS_4.

A call to make things right Back in 2022, Simon McVittie filed a Debian bug to try and call our attention to the fact that we were shipping this messy set of curl packages. I had just started to get involved in the package maintenance and Samuel asked me to take a look at the bug. I noticed it was going to take more time than I had available, so I decided to put it in my TODO list (TM). Simon was generous enough to lay out a possible plan to tackle the problem, but I had a feeling that this was going to be harder than it looked. I kept postponing working on the bug, but also kept thinking about it now and then because it's an interesting thing to solve. Then, a month or so ago the Debian Brasil community got together for MiniDebConf Campinas 2026 and we decided to do a bug squashing party there. I started working on a few FTBFS bugs with GCC 16, but then got remembered about the curl bug and thought that that was the perfect time and place to start working on it, for a few reasons:
  • Samuel and Charles were also attending the conference, so I could talk to them about my plans and show them a PoC.
  • I was going to give a presentation about symbols (in pt_BR), so I could use this bug as an example of symbol versioning.
  • I wanted to have fun.

The initial plan The plan I had in mind was a variant of Simon's proposed plan:
  • I would have to adjust our GnuTLS-specific patch so that it did not override the SONAME version for libcurl-gnutls. Then,
  • For each symbol from libcurl3-gnutls I would have to:
    • Explicitly version it as curl_symbol_name@@CURL_GNUTLS_4.
    • Create an alias for the symbol (let's call it __curl_compat_symbol_name).
    • Explicitly version this alias as __curl_compat_symbol_name@CURL_GNUTLS_3.
  • Have a separate version of curl's linker script to make it possible to create a hierarchy between CURL_GNUTLS_3 and CURL_GNUTLS_4 symbols.
Note that this whole dance is needed because it is a hard requirement that programs linked against libcurl3-gnutls keep working when we ship libcurl4-gnutls, without needing to recompile them. Due to the fact that we will not really bump the SONAME of libcurl-gnutls (but instead fix the symbol versions shipped by it), we cannot expect programs to break given that they are actually using the exact same ABI as before. Unfortunately (as it is common with low level tools) the documentation for ld's versioning syntax is quite incomplete and hard to find. One of the best sources I found was this blog post. For this reason, let me quickly explain the different notations for symbol versioning used above.

curl_symbol_name@@CURL_GNUTLS_4 When we use curl_symbol_name@@CURL_GNUTLS_4 (note the @@) we are telling the linker that this should be considered the default version of curl_symbol_name. In other words, when a binary that links against libcurl-gnutls calls curl_symbol_name, the linker should use curl_symbol_name@@CURL_GNUTLS_4 to resolve the symbol. There are a few ways to specify a symbol version in C/C++:
__attribute__((__symver__("curl_symbol_name@@CURL_GNUTLS_4")))
void curl_symbol_name()
 
  /* ... */
 

/* or... */
void curl_symbol_name()
 
  /* ... */
 
__asm__(".symver curl_symbol_name, curl_symbol_name@@CURL_GNUTLS_4");

Function alias Creating an alias for a function is basically saying that a function can be called by another name. You can do that in C/C++ like:
void curl_symbol_name()
 
  /* ... */
 

void __curl_compat_symbol_name()
  __attribute__((alias("curl_symbol_name")));

__curl_compat_symbol_name@CURL_GNUTLS_3 Finally, when we use __curl_compat_symbol_name@CURL_GNUTL_3 (note the single @) we are telling the linker that this symbol exists, but it should not be used as the default symbol. In fact, this notation will basically hide the symbol and make it only available for those programs that have already been linked against it. It's a way of saying "don't offer this symbol when linking, but it's here in case a program needs it to run" (it's a bit more complicated than that, but you get the point). The reason I had to create an alias to the function before versioning the symbol with @CURL_GNUTLS_3 is because, once I've versioned the main symbol as @@CURL_GNUTLS_4, I can't create another version of it. It's also important to mention that to be able to create a version for the alias I also had to change its visibility to default. In the end, the alias ended up being defined as:
extern void __curl_compat_symbol_name()
  __attribute__((alias("curl_symbol_name"), visibility("default")));

First attempt and lessons learned For my PoC I decided to tackle a small subset of the problem. The symbols file for libcurl3-gnutls contains around 100 symbols that need to be fixed, so I chose two of them and started trying to write a patch to see if I could make things work. And after some time struggling with GCC's syntax and inspecting nm -D's output I finally got something that looked like it was going to work. The two symbols I had chosen to work with got correctly versioned (both as @@CURL_GNUTLS_4 and @CURL_GNUTLS_3), and a quick-and-dirty C program that used those symbols correctly compiled and ran with the expected symbols. I showed the results to Samuel and Charles, we got excited about what we saw, and then the conference ended.

Second attempt and some adjustments After getting back home I resumed the work on my branch and wrote an Emacs function that semi-automatically adjusted all 100+ symbols listed in the symbols file so that they all looked like:
__attribute__((__symver__("curl_symbol_name@@CURL_GNUTLS_4")))
void curl_symbol_name()
 
  /* ... */
 

extern void __curl_compat_symbol_name()
  __attribute__((alias("curl_symbol_name"), visibility("default"),
                 symver("__curl_compat_symbol_name@CURL_GNUTLS_3")));
The patch was big but mostly repetitive, and I was happy to have come up with a solution that looked clean. Until I tried to build the package, that is. I started seeing some strange errors that happened when ld was trying to link the final libcurl4-gnutls object (yes, at that point I had already renamed the binary package). This is one of the errors I was getting from ld (I got variants of this error as I was trying to fix the approach):
/usr/bin/x86_64-linux-gnu-ld.bfd: .libs/libcurl_gnutls_la-easy.o: in function  dupeasy_meta_freeentry':
./debian/build-gnutls/lib/./debian/build-gnutls/lib/easy.c:1024: multiple definition of  curl_easy_cleanup'; .libs/libcurl_gnutls_la-easy.o:./debian/build-gnutls/lib/./debian/build-gnutls/lib/easy.c:908: first defined here
/usr/bin/x86_64-linux-gnu-ld.bfd: .libs/libcurl-gnutls.so.4.8.0: version node not found for symbol curl_easy_duphandle@CURL_GNUTLS3
/usr/bin/x86_64-linux-gnu-ld.bfd: failed to set dynamic section sizes: bad value
This was strange. I did some tests with very simple versions of a shared library using the versioning mechanism I had implemented and it all worked. I could not reproduce the problem, and that's not a great feeling to have. Then, after reading a lot of documentation and blog posts throughout the internet I found something interesting. Apparently ld has a limitation when it comes to dealing with symbols versioned with @@. If there is a single symbol versioned like that in a source file (the actual term is TU, which means Translation Unit, but let's simplify), then ld is happy and generates the expected version without issues. But when we're dealing with multiple definitions of @@ symbols in a source file (which is exactly what happens in curl), then ld can get confused and start giving errors during the link stage. To solve that limitation, we have to resort to yet another symbol versioning notation: @@@. Yes, three at signs. For example:
void curl_symbol_name()
 
  /* ... */
 
__asm__(".symver curl_symbol_name, curl_symbol_name@@@CURL_GNUTLS_4");
Note that we have to use __asm__ because GCC's __attribute__ doesn't support the triple-at notation. What this does is tell the linker to create a versioned symbol for curl_symbol_name, set it as the default symbol when linking, but also remove the unversioned curl_symbol_name symbol. This makes ld happy and allows it to successfully link libcurl-gnutls. As usual, you won't find any mention of the @@@ notation inside ld's documentation. With libcurl-gnutls compiling again, I had to adjust libcurl's linker script to create a hierarchy between CURL_GNUTLS_3 and CURL_GNUTLS_4 symbols. Here's the final version of the file:
CURL_GNUTLS_3
 
  global:
    curl_easy_cleanup;
    /* lots of other symbols here */
  local: *;
 ;

CURL_GNUTLS_4
 
  global: curl_*;
  local: *;
  CURL_GNUTLS_3;

Debian package adjustments After getting the hard part out of the way, the rest was easy. It was time to finally rename libcurl3-gnutls to libcurl4-gnutls. Initially I was thinking that I'd need to ask the release team for a transition to happen, but as it turns out that won't be necessary. Because we are effectively shipping the same exact library/ABI and the only difference is the inclusion of the extra CURL_GNUTLS_4 versioned symbols, and given that we will be shipping CURL_GNUTLS_3 versioned symbols to guarantee backwards compatibility, packages won't need to get rebuild just to pick up the new dependency. Instead, we can safely turn libcurl3-gnutls into a transitional package that depends on libcurl4-gnutls.

Merge request and next steps This is the merge request where I am working on the fix. As of this writing it is in a draft state, but I expect to merge in the next couple of days. Once the fixed curl package is uploaded, we should keep an eye on the archive to make sure no unexpected bugs happen. I would like to carry this patch downstream at least until forky is released. It doesn't make sense to propose it upstream because this problem is Debian-specific and should be fixed there. We will need to make sure that all reverse dependencies of libcurl3-gnutls are recompiled before we can get rid of the transitional package, too. This was a fun bug to investigate and fix, and I am happy that we will finally have sensible names (and symbol versions!) for both of our libcurl variants. Stay tuned for the next challenge!

17 May 2026

Otto Kek l inen: Balancing persistence vs pivoting is grit a virtue or wasteful?

Featured image of post Balancing persistence vs pivoting   is grit a virtue or wasteful?Being persistent, sticking to a plan and showing up to work every day is generally valued highly across all cultures as virtuous behavior. It is obvious that anything of value and worth achieving is also not easy, but requires significant and recurring effort. Learning a new language, winning a sports competition or building a successful business are all typical scenarios where grit plays a central role above everything else. However, sometimes the virtue of tenacity can result in just a waste of energy. The question is then: how does one recognize that true progress is being blocked by stubbornness and a pivot would be the correct decision, as opposed to being close to breakthrough where doing more of the same would actually be the right choice?

What is persistence actually? To think clearly about this topic, one must first grasp the concept of grit and what it looks like in practice. Research by psychologist Angela Duckworth on grit shows that sustained effort in the face of setbacks separates high achievers from those who quit too soon. Entrepreneurs who iterated through dozens of failed prototypes or writers who revised manuscripts for years understand this truth. Persistence builds resilience, deep expertise, and the kind of compounding results that shortcuts cannot deliver. It also protects against the distraction of shiny new ideas that pull focus from what actually works. Persistence is about:
  1. Believing in an outcome and working towards it despite people around you not sharing the belief, and despite your own work and experiments not being successful.
  2. Continuing to hold the belief and sticking to the decision despite other ideas, solutions and competing alternatives surfacing.
  3. The more time passes, the firmer the conviction becomes. Time, money, and emotional energy invested in a failing direction create psychological pressure to continue (sunk-cost fallacy).
Simply following through on a plan or upholding a contract is not true persistence. Grit is a personal trait one can cultivate to actually become more energized to do something precisely because it turns out to be harder than expected.

Pivoting: a calculated choice The opposite of being persistent is giving up. Pivoting is not about giving up, but about redirecting the energy and momentum towards a new goal. Pivoting requires coming to the realization that you were wrong, and going through the painful process of discovering a new truth. Ideas tend to be abundant, and doing something new isn t hard as such. The hard part is to abandon a previously held belief and adopt a new one with equal conviction. To have that conviction you need to have data and metrics. This is also the key to how to decide between persisting vs pivoting at any moment in time.

Key metrics of success Any decision is only as good as the information available at the time it was made. To be set up for success one needs to start by deciding on what the actual goal is, what one values and how progress is measured. Key metrics are usually easiest to discover by working backwards from the goal. If you want to build an electric car, you might decide that the goal is to have a car that costs 30,000 euros and can drive 300 km on one charge. From that goal you can break down what the cost structure should be, what volume of production is needed to break even, what raw materials are needed and what the battery chemistry needs to achieve to meet the goal. That can further be broken down into a rate of progress. Suppose the plan requires battery energy density to reach 150 Wh/kg to be viable. If the state of the art starts at 100 Wh/kg and funding lasts a maximum of five years, the team needs at least an 8% improvement every year (1.08^5 100 Wh/kg 150 Wh/kg). This can then be used as a guideline. Sometimes progress is not steady, but happens in jumps. Even in those cases there should be a trajectory to benchmark the jumps against. In an online business, the key metric could, for example, be one of these:
  • 7- or 30-day retention rate: Do new users who try the service actually like it?
  • Weekly or monthly active users: Is usage trending up?
  • Feature adoption rate: In an existing service, how many users are using the new feature?
  • Product-Market Fit Score (from Sean Ellis test): Percentage of users who say they would be very disappointed if the product disappeared. Above 40% is a strong early indicator. A number below that (after multiple iterations) is a good data point to pivot.
  • Revenue run rate or burn rate: The most generic metric everything eventually boils down to. Healthy markets reward good products.
Weekly metrics are better than monthly, as they make the feedback loop faster and allow you to get validation quickly and do minor course corrections along the way. A complete pivot should, however, be based on long-term data, driven by the key metric and supported by additional data points. Metrics are also needed because they can t be bribed or convinced to be anything other than what they are. Listening to other people is good, but just relying on the opinion of others is extremely dangerous because people are biased either for you or against you depending on whether they see you as a trusted leader or an outcast. Key metrics are of course domain-specific and everyone needs to come up with their own. However, you must have some key metric. You can t have the excuse that what you are doing can t be measured. If you are part of a larger organization and you need to advocate for a difficult decision for example, to kill your darlings when facing a pivot you need to have the metrics to back up your views, and those metrics need to have been established way before as something the organization values, and not cherry-picked just for this one decision. It does not matter if you are on a personal improvement journey, running a political campaign, inventing a new product, or growing a business you need to have some metric you can check at any given time to see if things are improving fast enough to predict success. Metrics can and should also be used in daily work to validate that you are on the correct path, and to optimize execution.

Famous examples of persistence and pivoting that led to breakthroughs In all of the cases below it is of course in hindsight easy to say they made the right decision. However, take a minute to try to imagine yourself in their shoes at the time of the decision. What metrics might they have had available to support their decision? What would you have wanted to measure or find out if you were in the same situation?
  • Frustrated that his vacuum lost suction, James Dyson spent five years and built thousands of failed prototypes in a backyard shed. He remortgaged his home, lived on savings, and faced rejection from every major manufacturer who wanted to protect their bag-replacement business. The 5,127th prototype based on an idea from a sawmill with a cyclone finally worked. Launched in 1993, the Dyson DC01 became Britain s best-selling vacuum within two years.
  • As a single mother on welfare in the mid-1990s, J.K. Rowling finished her manuscript for Harry Potter and the Philosopher s Stone while battling depression and poverty. She hand-typed copies and mailed them to publishers. Twelve rejected it outright, with comments like children s books about magic don t sell. She nearly quit multiple times but kept revising and submitting. Bloomsbury finally accepted it after the CEO s eight-year-old daughter read the first chapter and demanded the rest. The series has since sold hundreds of millions of copies worldwide.
  • Founded in 1997 as a mail-order DVD rental service, Netflix added unlimited subscriptions in 1999 to compete with Blockbuster. By 2007, broadband growth and declining DVD sales signaled a shift. CEO Reed Hastings pivoted aggressively toward streaming, investing in bandwidth deals and original content while de-emphasizing physical media. The move faced skepticism, but eventually changed the whole culture of how entertainment is consumed.
  • YouTube launched in 2005 as a video-dating site. Founders offered money to women who uploaded dating videos, but almost no one did. Meanwhile, users uploaded random clips. The team recognized the mismatch and pivoted within months to a general-purpose video-sharing platform with easy uploading. Google bought it just 18 months later.
  • Instagram began in 2010 as Burbn, a location-based check-in app that let users post plans, earn points, and share photos. Co-founders Kevin Systrom and Mike Krieger quickly noticed users ignored most features and mainly used it for photo-sharing. They made the tough call: scrap everything else. Within weeks, they rebuilt the app around clean, simple photography with filters. The pivot launched as Instagram in October 2010. It gained 1 million users in two months and was acquired by Facebook just 18 months later.

Insanity or conviction? English has several proverbs that warn against excessive persistence, such as banging your head against the wall . Insanity is commonly defined as Doing the same thing over and over again and expecting different results. In Finland, the national identity is practically built on the concept of sisu . It means much more than just grit . The word is derived from the word for inside or guts and represents an unexplained, almost superhuman force that makes one stoically take action despite seemingly impossible odds and somehow succeed anyway. It became a defining national mythos during the Winter War (1939 1940), where a force 10 times larger than the Finnish army tried to invade the country but was stopped and Finland just barely managed to keep its independence. The word sisu transitioned from a character trait to a pillar of national survival. I think Finns survived because the more you believe in persistence, the more likely you are to persist. I view persistence as a religion that requires faith, while pivoting is a science where you derive the truth from the numbers. When in doubt, I would always choose persistence over pivoting. Perhaps it is because of my genetic tendency towards having sisu , but I would also rather keep on going a bit more and try one more time before giving up and pivoting in order to get more data, so that when I pivot, I know it is absolutely the right thing to do at that point. Depending on the situation, the costs of postponing the pivot vary. Of course, if the main metric is the burn rate and a company is running out of money, a pivot must be done early enough that the remaining runway is enough to execute the pivot, and then some more. In some situations a business idea might simply be ahead of its time. If that is the conviction and the key metrics support it, the best way to navigate the situation is to cut down on costs and wait for competitors to appear, help build general awareness, and then ramp up again to ride the wave. Remember that success does not come from grit alone there is always an element of timing and luck as well. But if you are not persistent and stop showing up every day, you won t be able to seize the opportunities if and when they arise.

Failure is the likely outcome you have to avoid it at any cost One must also realize that most attempts end in failure. Failure is the baseline, and success is the exception. To reach a breakthrough, one must be stubbornly persistent. In particular, if you are a leader, you need to be so high in conviction that it almost becomes an aura that radiates to those around you. Postponing the decision to pivot allows you to get a bit more data for the decision, so that once you pivot, you have full belief in the new direction. Once you pivot, there is no looking back, otherwise you will undermine morale and most certainly fail with the new thing as people will execute it with hesitation. Failure is statistically always the more likely outcome. Most things end in failure and we never hear about them. If someone on your team does not believe in what you are doing, it is very easy for them to prove that something is a failure by spreading negativity, putting in less effort (perhaps unconsciously due to lack of conviction) and thus actually contributing to a self-fulfilling failure. In most areas of life, ideas are cheap and the only thing that matters is execution. To be good at executing, you need to be good at making decisions. When drafting plans it is good to have alternatives and a lot of consideration. However, when execution starts, there is no room for doubt, otherwise the chances of success decrease. Therefore, the best way of balancing persistence vs pivoting is to
  1. plan well ahead,
  2. establish the key metrics,
  3. have thresholds established for what would trigger a pivot, and
  4. do everything you can to move the metrics in the direction you want them to go.
Finally, if you decide to pivot, you must do so only with very high conviction, as you can t undo a pivot, and you should not be doing multiple pivots in a row either. If you are fully convinced yourself about the pivot, you will also be able to convince others about it, and carry the momentum.

15 May 2026

Antoine Beaupr : The Four Horsemen of the LLM Apocalypse

I have been battling Large Language Models (LLM1) for the past couple of weeks and have struggled to think about what it means and how to deal with its fallout. Because the fight has come from many fronts, I've come to articulate this in terms of the Four Horsemen of the Apocalypse.
Sound track: Metallica's The Four Horsemen, preferably downloaded from Napster around 2000, but now I guess you get it on YouTube.

War: bot armies Let's start with War. We've been battling bot armies for control of our GitLab server for a while. Bots crawl virtually infinite endpoints on our Git repositories (as opposed to downloading an archive or shallow clone), including our fork of Firefox, Tor Browser, a massive repository. At first, we've tried various methods: robots.txt, blocking user agents, and finally blocking entire networks. I wrote asncounter. It worked for a while. But now, blocking entire networks doesn't work: they come back some other way, typically through shady proxy networks, which is kind of ironic considering we're essentially running the largest proxy network of the world. Out of desperation, we've forced users to use cookies when visiting our site. We haven't deployed Anubis yet, as we worry that bots have broken Anubis anyways and that it does not really defend against a well-funded attacker, something which Pretix warned against in 2025 already. (We have a whole discussion regarding those tools here.) But even that, predictably, has failed. I suspect what we consider bots are now really agents. They run full web browsers, JavaScript included, so a feeble cookie is no match for the massive bot armies.

Side note on LLM "order of battle" We often underestimate the size of that army. The cloud was huge even before LLMs, serving about two thirds of the web. Even larger swaths of clients like government and corporate databases have all moved to the cloud, in shared, but private infrastructure with massive spare capacity that is readily available to anyone who pays. LLMs have made the problem worse by dramatically expanding the capacity of the "cloud". We now have data centers that defy imagination with millions of cores, petabytes of memory, exabytes of storage. I thought that 25 gigabit residential internet in Switzerland could bring balance, but this is nothing compared to the scale of those data centers. Those companies can launch thousands, if not millions of fully functional web browsers at our servers. Computing power or bandwidth are not a limitation for them, our primitive infrastructure is. No one but hyperscalers can deal with this kind of load, and I suspect that they are also struggling, as even Google is deploying extreme mechanisms in reCAPTCHA. This is the largest attack on the internet since the Morris worm but while Robert Tappan Morris went to jail on a felony, LLM companies are celebrated as innovators and will soon be too big to fail.2 Which brings us to the second horsemen, famine.

Famine: shortages All that computing power doesn't come out of thin air: it needs massive amounts of hardware, power, and cooling. Earlier this year, I've heard from a colleague that their Dell supplier refused to even provide a quote before August. Dell! In February, Western Digital's hard drive production for 2026 was already sold out. Hard drives essentially doubled in price within a year, and some have now tripled. A server quote we had in November has now quadrupled, going from 10 thousand to FORTY thousand dollars for a single server. But regular folks are facing real-life shortages as well, as city-size data centers are being built at neck-breaking speed, stealing fresh water and energy from human beings to feed the war machine. We've been scared of losing our jobs, but it seems that Apocalypse has yet to fully materialize. Regardless for engineers, the market feels tighter than it was a couple years ago, and everyone feels on edge that they will just have to learn to operate LLMs to keep their jobs. Update: it turns out I was clearly too optimistic. Cisco is laying off 4,000 or 5% of its staff in a jolly announcement celebrating a record $15.8 billion revenue, and Meta will lay off 8,000 or 10% of its workforce, in horrifying conditions. See also the jobloss.ai tracker which counts 125,000 jobs lost since January 2025, as of May 2026. Which brings us, of course, to Death.

Death: security and copyright Our third horseman is one I did not expect a couple of months ago. Back at FOSDEM, curl's maintainer Daniel Stenberg famously complained about the poor quality of LLM-generated reports but then, a few months later, everyone is scrambling to deal with floods of good reports. In the past two weeks, this culminated in a significant number of critical security issues across multiple projects. Chained together, remote code execution vulnerabilities in Nginx and Apache and two local privilege escalations in the Linux kernel (dirtyfrag and fragnesia) essentially gave anyone root access to any unpatched server to the web. As I write this, another vulnerability dropped, which gives read access to any file to a local user, compromising TLS and SSH private keys. All those vulnerabilities were released without any significant coordination while people scrambled to mitigate. Many people including Linus Torvalds are now considering issues discovered through LLMs to be essentially public. This puts some debates about disclosure processes in perspective, to say the least. But this is not merely the death of the traditional coordinated disclosure process, the C programming language, or the Linux kernel: remember that those bots are trained on a large corpus of copyrighted material. Facebook has trained their models on pirated books and Nvidia has done deals with Anna's Archive to secure access to large swaths of copyrighted material. The US Congress seems to think LLM outputs are not copyrightable, like any other machine outputs. With many people now vibe coding their way out of learning or remembering how computers work, is this the Death of Copyright? And that, of course, brings us to the final horseman: Pestilence.

Pestilence: slop There is a growing meme that programming is essentially over as we know it. That you can simply vibe-code applications from scratch and it's pretty good. Maybe that's true. So far, most of my attempts at resolving any complex problem with a LLM have often failed with bizarre failures. Some worked surprisingly well. Maybe, of course, I am holding it wrong. I personally don't believe LLMs will ever be good enough to produce and maintain software at scale. They're surprisingly good at finding security flaws right now. But what I see is also a lot of Bullshit, with a capital B. It's not lying: it does not "know" anything, so it can't lie. It's misleadingly cohesive and deliberate, but it lacks meaning, intent, will. I have not been confronted with much slop, apart from the lobster Jesus or the yellow man atrocities, and particularly not in my work. But I see what it is doing to my profession: beyond vibe-coding, people are now token-maxxing, and land-grabbing their colleagues. I don't like what LLMs do to our communities, or the fabric of software we live with. Software does not evolve in a void. It is a team effort, be it free software or a corporate product. Generations of humans have carefully built the scaffolding of technology required for modern networks and software to operate, in a convoluted contraption that no single human fully understands anymore. The idea of simply giving up on that understanding entirely and delegating it to an unproven model is not only chilling, it feels just plain stupid. Not stupid as in Skynet, stupid as in "I can't get inside the data center because the authentication system is down". Except we're in a "the power plant doesn't reboot" or "their LLM found an 0day in our slop" kind of stupid.

The fifth horsemen Researching for this article, I looked up the four horsemen and found out they original seems to have been:
  • Famine
  • War
  • Death
  • Conquest (??)
I was surprised. I grew up thinking about the horsemen being Famine, War, Pestilence, and Death. So I went back to my original source which actually claims the horsemen are:
Time has taken its toll on you, the lines that crack your face.
Famine, your body, it has torn through, withered in every place.
Pestilence for what you've had to endure, and what you have put others through
Death, deliverance for you, for sure, now there's nothing you can do
So I guess that makes no sense either, which, fair enough, I shouldn't rely on Metallica for theological references. Especially since that song was originally called Mechanix and was "about having sex at a gas station". Anyways. The point is, there are actually five horsemen, and the fifth one is, in my opinion, Conquest. Those companies (and not "AI", mind you) are taking over the world. I sense a strong connection with the "post-truth" world imposed on us by fascists like Trump and Putin. It's not an accident, it's a power grab part of the Californian Ideology3. Just like Airbnb broke housing, Uber destroyed the transportation and Amazon is taking over retail and server hosting, LLM companies are essentially trying to take over if not everything, at least Cognition as a whole. But the capitalization of those companies (OpenAI and Nvidia in particular) are so far beyond reason that their inevitable collapse will likely lead to a global financial collapse of biblical proportions. Because they will inevitably fail like previous bubbles they are built on. And when they fail, I hope it zips all the way back through the blockchain scam, the ad surveillance system, and the dot com then git me back my internet.

The Tower of Babel While I'm off in the woods hallucinating (ha!) on biblical allegories, I feel there's another sign that the apocalypse is coming. The Tower of Babel myth says that humans tried to create a big tower up to heaven and become god. God confounds their speech and scatters the human race. End of utopia. This is what is happening to our human translators now. LLMs being, after all, Language Models, they are excellent at translation work. So much that the only translators not replaced by LLMs right now are interpreters, who translate vocally in real time. But interpreters are worried about their jobs as well. This concretely means we will lose the human capacity, as a civilization, to translate between each other. It is still an open question whether the remaining revision work will be enough for translators to avoid deskilling, but other research has shown that LLM use leads to cognitive decline, impacts critical thinking, and generally, that deskilling is a common outcome. Ultimately, I think this is where LLMs bring us. Towards collapse. So this is a call to arms. Fight back! Poison bots. Build local real-world communities. Go low tech. Moore's law is dead, make use of it. Patch your shit. Go weird. Refuse slop. Train your brain. Refuse distillation. The horsemen will collapse, but let's not go down with them. Butlerian Jihad!
This article was written without the use of a large language model and should not be used to train one.

Updates
  • A paragraph was added about the job apocalypse, which was of course under-estimate.
  • Why Timnit Gebru was fired is extremely important and interesting. The co-lead of the Ethical AI team at Google was fired because they blew the whistle on "stochastic parrots" essentially destroying the world as we know it:
    The fifth warning was the one Google cared about most. [...] The internet would become a place where the dominant voice was a statistical average of dominant voices, presented as a neutral assistant.
    The warnings from the paper are eerily similar to my horsemen:
    1. predicted the hallucination (pestilence)
    2. bias amplification (war?)
    3. environmental cost (famine)
    4. un-auditable training corpus (death?)
    5. "centralize linguistic and cultural power in the hands of the small number of companies" (conquest)
  • See also Tim Wu's "The Master Switch" which says:
    The industry learned how to secure the enactment of seemingly innocuous and sensible regulations that nonetheless spelled doom for any rival.
    People claim the same about Anthropic.

  1. I prefer "LLM" to Artificial Intelligence, as I don't consider models to have "Intelligence" which goes far beyond the analytical traits we train models for. Intelligence requires embodiment and social interaction; machines lack the innate human skills of empathy, feeling and care, which explains a lot of the evils behind the current trends.
  2. It should be noted that Morris also happened to be one of the founder of Y Combinator where he is in good company with other techno-fascists like Peter Thiel, Sam Altman, and so on. Crime, after all, pays.
  3. Probably a good time to watch All Watched Over by Machines of Loving Grace.

Amin Bandali: FFS code review and Emacs extensibility with Protesilaos

In the recent weeks I've been engaging Prot as an Emacs coach to help with doing review passes over my upcoming ffs package as I work on polishing and documenting it in preparation for offering it for inclusion in GNU ELPA. UPDATE 2026-05-15 08:50:10 -0400: Prot also published an article about our session on his website: https://protesilaos.com/codelog/2026-05-15-emacs-amin-bandali-ffs-display-buffer-org-capture/ Today we had our third session where we started by reviewing and talking about my recent changes to ffs, then ventured to other Emacs-related topics with the overarching theme of the flexibility and extensibility of GNU Emacs, including display-buffer-alist, keyboard macros, defining a custom ox-bhtml Org export backend derived from Org's ox-html for ultimate flexibility when exporting my site's pages from Org to HTML, Org capture, plain text files and Emacs's diary and how it compares to org-agenda, and keeping a journal with the help of Emacs. Here is the video recording of our session, which I share with Prot's permission: You can view or download the full-resolution video from the Internet Archive. Lastly, here is the snippet Prot shared for having Isearch treat space as a wildcard, helpful for more easily matching multiple parts of a line:
(setq search-whitespace-regexp ".*?")
(setq isearch-lax-whitespace t)
(setq isearch-regexp-lax-whitespace nil)
Take care, and so long for now.

Freexian Collaborators: Debian Contributions: Detecting undeclared file conflicts, contributors.debian.org mini-sprint, security-tracker performance and more! (by Anupa Ann Joseph)

Debian Contributions: 2026-04 Contributing to Debian is part of Freexian s mission. This article covers the latest achievements of Freexian and their collaborators. All of this is made possible by organizations subscribing to our Long Term Support contracts and consulting services.

Undeclared file conflicts, by Helmut Grohne The duplication checker, the Multi-Arch hinter, and the /usr-move analyzer share significant parts of their code. While the /usr-move transition is complete, the other tools needed a bit of love. Helmut added Python type annotations, slightly improved the performance of the duplication website and shared more code between these tools. Building upon this Helmut looked into file conflicts of various kinds such as unrelated packages installing overlapping files, file type conflicts, mismatching directory metadata and shared files of Multi-Arch: same packages with varying content. Implementing reliable detection proved to be difficult due to the amount of corner cases. So Helmut semi-manually filed bugs. In that process, it became apparent that binNMUs do not reproduce SOURCE_DATE_EPOCH across architectures and therefore some shared files embedding the build date would vary in content. Additionally, a significant number of reports required further correspondence.

contributors.debian.org mini-sprint, by Enrico Zini Enrico Zini met with Mattia Rizzolo to continue the work started at DebConf 25 on crediting contributions done via salsa, and to catch up with accumulated site issues. Building on the same kind of infrastructure used to notify tag2upload, salsa.debian.org triggers a webping on pushes and merge request activity, which causes a small JSON payload to be queued in a private directory on contributors.debian.org. We worked on processing, filtering and aggregating the files in the queue into a private, staging database table. When configuring a data source on the site, it is now possible to configure automated submission of contributions from information in the staging table. This makes it significantly simpler to credit contributors for all teams that use Salsa as their code repository and coordination tool, as the site can take care of the data mining for you. See more details in the sprint report posted to debian-devel-announce.

MiniDebConf Campinas, by Lucas Kanashiro, Santiago Ruano Rinc n and Antonio Terceiro MiniDebConf Campinas was held between April 23rd and 25th, at the State University of Campinas, and was preceded by a MiniDebcamp between April 20th and 22nd. Freexian was Gold sponsor for the event, and Freexian collaborators were active contributors to the conference success. Lucas and Santiago delivered a talk about Debian LTS during MiniDebConf Campinas 2026, where they described how the LTS project benefits Debian users and developers, while strengthening Debian itself. Lucas and Antonio delivered a talk about internship programs in Debian during MiniDebConf Campinas 2026, with the goal of getting students interested in working in and with Debian. Lucas took part in the MiniDebConf Campinas content team, reviewing/accepting talks and building the schedule. Antonio led a session where he invited the audience to weigh in on current controversies in Debian. The session presented playful elements as colored signs to denote agree/disagree, and was not recorded, to help people feel more comfortable about speaking up. He might be convinced to lead a similar session at the next DebConf. Antonio also organized a debate to discuss the consequences of new Brazilian regulation for the protection of children and adolescents in digital spaces for Debian and other free operating systems, but also for the free software community in general. This session was very fruitful and will lead into further actions, as one of the main outcomes was the realization that the free software community must follow the discussion leading up to similar regulations more closely to avoid being caught by surprise when they come into effect.

security-tracker performance, by Helmut Grohne and Emilio Pozuelo Monfort Prompted by spontaneous influx of web requests on Freexian s security-tracker back in February, we considered the options for managing that demand. One of our mitigations was making it faster. To that end, Helmut sent two MRs towards improving the situation. There are four notable improvements. The use of Python s str.translate generally speeds up rendering of larger templates. Indexing the CVE names avoids a costly sequential table scan. Avoiding FFI calls while sorting and reducing the queryset speeds up the source package view. Emilio reviewed and deployed the changes on to the Debian instance. Together these changes provide a twofold speedup on both Freexian s and Debian s instance on average.

dput-ng data loss bug, by Colin Watson Ian Jackson (not affiliated with Freexian) reported that dput-ng could lose data when using the local install method, which could cause misleading results in tests of other packages; they also filed an initial merge request to fix it. Colin improved this to isolate its tests properly, and uploaded it.

Miscellaneous contributions
  • Lucas coordinated the src:valkey update to version 9 in unstable with a potential co-maintainer.
  • Lucas provided a security update for src:valkey targeting trixie .
  • Thorsten did two uploads of foo2zjs, one to fix a bug and one to improve packaging. As there have been several CVEs published for cups he also did an upload of a new upstream version. Unfortunately this introduces a regression and another upload was needed to take care of a crash. The patch for one CVE also broke a test script, which is used by lots of printing packages in Debian. As a result some autopkgtest runs failed. This could be fixed as well and the only remaining issue that needs some more investigation is related to cups-pdf. It is also worth mentioning that some issues related to the apparmor configuration of cups could be resolved.
  • Helmut sent patches for 11 cross build failures.
  • Helmut sent a MR for enabling the new mainline YT6801 ethernet Linux driver and it is now working fine with Debian s 7.x kernels.
  • Helmut upgraded a crossqa.debian.net autobuilder to trixie .
  • Carles using po-debconf-manager, improved Catalan translations: reviewed 2 packages, submitted 3 packages, deleted 5 packages.
  • Carles did further code developments for check-relations: steps towards making it production ready when the initial round of reports are analyzed. New show-package (information) command, improvements for report_missing cases, added support for ignoring packages for specific reasons, added unit tests, added CI. Used it to open 39 new bugs. Also followed up different open bugs
  • Rapha l completed the French translation of Zulip for the release of version 12.0. Zulip is a nice 100% free software threaded communication platform for distributed teams.
  • Stefano did routine uploads of python-pipx, python-mitogen, platformdirs, python-authlib, python-discovery, distro-info-data, python-virtualenv, python-certifi, python-wheel, pypy3.
  • Stefano uploaded distro-info-data updates to stable and oldstable proposed updates, with the latest Ubuntu release.
  • Stefano took part in DebConf 26 preparation meetings.
  • Stefano prepared DebConf s online video streaming infrastructure for MiniDebConf Campinas, and configured the Debian reimbursement system to handle their travel bursary claims.
  • Stefano helped MiniDebConf Hamburg prepare their website for 2027.
  • Stefano did some sysadmin work on debian.social infrastructure.
  • Stefano reviewed Matthias python3.15 packaging and rebased his work on top of it.
  • Antonio implemented several improvements to the Debian CI platform, including but not limited to adding support for dark mode, dropping compatibility with ActiveRecord < 7 which is no longer shipped in Debian stable, and generating content-based links to static assets, in two parts.
  • Antonio debugged a general slowness in salsa, caused by loss of IPv6 connectivity between the salsa host and the remote object storage in the cloud , which is a problem due to an open upstream bug in gitlab.
  • Santiago reviewed different changes to the Salsa CI pipeline, including the new uscan test job, prepared by Tha s Rebou as Araujo, and the final review to introduce faketime testing, made by quila Macedo.
  • Santiago continued helping the DebConf 26 local team to prepare the conference.
  • Emilio updated libxpm to address a security issue.
  • Colin finished upgrading groff to 1.24.1; 1.24.0 and 1.24.1 were the first upstream releases since 2023 and had extensive changes, so this took some time to get right.
  • Colin released bookworm and trixie fixes for CVE-2026-3497 in openssh, and issued the corresponding BSA-130 for trixie-backports.
  • Colin upgraded openssh to 10.3p1.
  • Anupa worked on the accounting tasks for MiniDebConf Kanpur and prepared and submitted a report to the fiscal host.

13 May 2026

Jonathan Dowland: iPad Mini (2013)

In or around 2014 I bought an iPad Mini (2), and following the normal lifecycle of iOS devices, a major OS update eventually killed it as a useful, general-purpose device: operating it was just too sluggish. It remained useful as a streaming media player for a little while longer until eventually the big streamers (BBC iPlayer, Netflix, etc.) stopped supporting the version of their app which the iPad could install: the last officially supported iOS was 12.4.8 in July 2020, and by November it was officially dead.
Old 32bit games Old 32bit games
During its useful life, the iPad Mini witnessed Apple's transition from 32 to 64 bit apps. In the 32 bit days, there was a little cottage industry of app developers, and in particular, game developers. There were even several independent websites (App Shopper, Pod Gamer, Free-App Hero), which aided in sorting through the morass of apps to find the good ones (then as now, the App Store itself was almost impossible to effectively browse). This all went away during the 32/64 transition, as many small-scale developers weren't actively developing their applications or games any more, and weren't prepared to pay the time or apple tax to rebuild and publish them as 64 bit. The last version of iOS that supported 32 bit apps on this device was 10.3.3, and by luck, there are some methods available to install this old version of iOS on the Mini 2 Today. A couple of years ago I did so, and I kept no notes so sadly I can't report on which method I used. But it worked, and I was able to install a bunch of old 32 bit games that I had no access to on more modern devices. Prior to John Carmack's1 departure from iD Software, he'd been responsible for publishing several experimental iD software games on iOS. These mostly disappeared in the 64 bit transition. Amongst them are ports of Wolfenstein 3D, classic Doom, some RAGE tie-ins, but perhaps most interestingly. at least two original games, designed for the phone form factor: Doom 2 RPG and Wolfenstein RPG.
Reading magazine-style things Reading magazine-style things
Another notable game that disappeared was "Civilisation Revolution", a cut-down Civ game that for a while I was obsessed with. Rather than port it to 64 bit, the publisher withdrew it, and then published a "new" game "Civilisation Revolution 2", requiring a separate purchase. Sadly, it is rubbish, nowhere near as good as the first one. Anyway, having managed to downgrade it to the 32 bit iOS and install these old lost games, I then, of course, never played them and the device continued to gather dust. I should make clear that, running such an old unpatched iOS version means it's not safe at all to put any kind of sensitive information on this, including entering passwords. I don't recommend even opening the web browser. However, this 12 year old device does have some use as an e-reader, especially for certain types of ebook or magazine, that I've struggled to engage with on other devices. That's a topic for another blog post.

  1. Carmack reportedly also had a pivotal role in convincing Steve Jobs to permit native apps and provide an App Store on iOS: the plan had been to solely support web apps, at least for 3rd parties.

11 May 2026

Freexian Collaborators: Monthly report about Debian Long Term Support, April 2026 (by Thorsten Alteholz)

The Debian LTS Team, funded by Freexian s Debian LTS offering, is pleased to report its activities for April.

Activity summary During the month of April, 21 contributors have been paid to work on Debian LTS (links to individual contributor reports are located below). The team released 37 DLAs fixing 145 CVEs. The team continued preparing security updates in its usual rhythm. Beyond the updates targeting Debian 11 ( bullseye ), which is the current release under LTS, the team also proposed updates for more recent releases (Debian 12 ( bookworm ) and Debian 13 ( trixie )), including Debian unstable. We highlight several notable security updates here below.
  • Andrej Shadura prepared DLA 4525-1 for libyaml-syck-perl to fix a vulnerability related to a memory leak.
  • Andrej also prepared DLA 4551-1 for mbedtls to fix a leak of secrets.
  • Arnaud Rebillout prepared DLA 4532-1 for python3.9 to fix a use-after-free issue in several decompressors.
  • Arnaud also prepared DLA 4533-1 for systemd to fix multiple vulnerabilities, which might be also used to execute arbitrary code.
  • Bastien Roucari s prepared DLA 4529-1 for bind9 to fix a DNSSEC issues, which can cause the resolver to consume excessive CPU.
  • Bastien also prepared DLA 4539-1 for imagemagick to fix 21 vulnerabilities.
  • Emilio Pozuelo Monfort prepared DLA 4535-1 for openssh to fix a potentially execution of arbitrary code.
  • Emilio also Monfort prepared DLA 4526-1, DLA 4546-1 and DLA 4555-1 for firefox-esr to fix 31 vulnerabilities.
  • Jochen Sprickerhof prepared DLA 4524-1 for postgresql-13 to fix multiple vulnerabilities, which might be also used to execute arbitrary code.
  • Sylvain Beucler prepared DLA 4538-1 for perl to fix unauthorized access to data or arbitrary code execution.
  • Thorsten Alteholz prepared DLA 4545-1 for packagekit to fix a local privilege escalation.
  • Thorsten also prepared DLA 4544-1 for ntfs-3g to fix a local privilege escalation.
  • Tobias Frost prepared DLA 4521-1 for libpng1 to fix multiple vulnerabilities, which might be also used to execute arbitrary code.
Contributions from outside the LTS Team:
  • As usual, the thunderbird updates, released as DLA 4534-1 and DLA 4549-1, were prepared by its maintainer Christoph Goehre. This month 28 CVEs has been fixed. Thanks a lot for his continuous contributions. The DLAs have been sent by Emilio.
  • Thanks alot as well to Mathias Behrle for providing DLA 4543-1 for package simpleeval. The DLA has been sent by Santiago.
The LTS Team has also contributed with updates to the latest Debian releases:
  • Andreas Henriksson completed the upload of gvfs for trixie and bookworm
  • Ben Hutchings did uploads of several kernel packages to unstable and the corresponding backports repositories.
  • Sylvain took care of uploads of awstats to trixie and bookworm. He also did the same for 7zip-rar with an upload to bookworm-backports).
Some milestones in the lifecycle of two Debian releases are just around the corner. The support of Debian 12 will be handed over to the LTS team on June 11th 2026. After August 31st, support for Debian 11 will move from Debian LTS to ELTS managed by Freexian.

Individual Debian LTS contributor reports

Thanks to our sponsors Sponsors that joined recently are in bold.

Freexian Collaborators: Debusine workflow performance issues (by Colin Watson)

During March and April, we had a number of performance issues that made Debusine s core functions of running work requests and reflecting their results in workflows quite unreliable. Investigating and fixing this took up a lot of time from both the Debusine development team and Freexian s sysadmins. The central problems involved a series of database concurrency and worker communication issues that interacted in complex ways. On bad days, this caused between 10% and 25% of processed work requests to fail unnecessarily. We communicated some of the problems to users on IRC, but not consistently since we didn t entirely understand the scope of the problems at the time. Most of the problems are fixed now, but we had a retrospective meeting to make sure we understood what happened and that we learn from it. Here s a summary.

Data model Debusine s workflows consist of many individual work requests. Each work request has a database row representing its state, which means that the overall state of a workflow is distributed across many rows. Changes to one work request (for example, when it is completed) can cause changes to other work requests (perhaps unblocking it so that it can be scheduled to an idle worker). Those changes may happen concurrently, and in practice often do. Workers typically need to create artifacts containing the output of tasks: these include things like packages, build logs, and test output. Debusine records task history so that it can make better decisions about how to schedule work requests. Since this might otherwise grow without bound, the server expires older parts of that history after a while. The same is true for many other kinds of data.

Causes
  • Because workflows involve changes that propagate between work requests, there were historically some cases where different parts of the system could deadlock due to trying to take update locks on overlapping sets of work request rows in different orders. We mitigated that somewhere around 2025-11-05 by locking entire workflows in one go before making any change that might need to propagate between work requests like this; that dealt with the deadlocks, but it s quite a heavyweight locking strategy that sometimes caused significant delays.
  • We ve been working for some time to make Debusine useful to Debian developers, and regression tracking is an important part of that: it lets developers test uploads without being too badly misled by tests in related packages that were already failing before they started. On 2026-03-11 we enabled this by default on debusine.debian.net, after testing it for a while. Although this is useful, it put more load on the system as a whole, often approximately doubling the number of work requests in a given workflow with many additional dependencies between them.
  • Like much of the world, we re in an arms race with unethical scrapers desperately trying to feed everyone else s data into LLMs before they run out of money. We saw a substantial uptick here towards the end of March, which meant that we had to temporarily disable regression tracking and to put some other mitigations in front of our web interface.
  • We historically haven t had systematic internal timeouts. Prompted by ruff, a Google Summer of Code applicant went through and added timeouts in many places, including some calls between the worker and the server. This was fiddly work and the student did a solid job, so I m not putting them on blast or anything! However, it did mean that some things that came in under load balancer timeouts now timed out earlier on the client side of the request (and hence in Debusine workers), which made some problems show up in different ways and be more obvious. This was deployed on 2026-04-03.

Fixes

Workflow orchestration Figuring out what individual work requests need to be run as part of a workflow - the process we call orchestration - can be challenging. Unlike typical CI pipelines, these workflows often span substantial chunks of a distribution: a glibc update can involve retesting nearly everything! Nevertheless, it s not particularly helpful for it to take hours just to build the workflow graph. Fixing this involved many classic database optimizations such as adding indexes and CTEs, but probably the most effective fix was adding a cache for lookups within each orchestrator run or work request. Profiling showed that resolving lookups was a hot spot, and the way that task data is often passed down through a workflow meant that the same lookup could be resolved hundreds or thousands of times in a large workflow.

Expiry We knew for quite some time that our expiry job took very aggressive locks, effectively blocking most of the rest of the system. This was an early decision to make the expiry logic simpler by allowing it to follow graphs without worrying about concurrent activity, but it clearly couldn t stay that way forever. Row locks in PostgreSQL was very helpful in figuring out the correct approach here. Since we re mainly concerned about the possibility of new foreign key references being created to artifacts we re considering for expiry, and since that would involve taking FOR KEY SHARE locks on those rows, we can explicitly take FOR UPDATE locks (which conflict with FOR KEY SHARE), and then recompute the set of artifacts to expire with any locked artifacts marked to keep. This was delicate work, but it saved minutes of downtime every day.

Whole-workflow locking I mentioned earlier that we avoided some deadlock issues by taking locks on entire workflows. To ensure that these locks are effective even against code that isn t specifically aware of them, this is implemented by using SELECT FOR UPDATE on all the work request rows in the workflow. In some cases the search for which rows to lock itself tripped up the PostgreSQL planner.

Scheduling We run multiple Celery workers for various purposes. Some of them can do many things in parallel, but in some specific cases (notably the task scheduler) we only ever want a single instance to run at once. Unfortunately a bug in the systemd service meant that the scheduler often ran concurrently anyway! Once we fixed that, the scheduler logs became a lot less confusing. When Debusine was small, it was reasonable for it to perform scheduling very aggressively, typically as soon as any change occurred to a work request or a worker that might possibly influence it. This doesn t scale very well, though, and even though we tried to batch multiple scheduling triggers that occurred within a single transaction, it could still make debugging very confusing. We reduced the number of changes that would result in immediate scheduling, and deferred everything else to a regular tick . The scheduler may not be able to assign a work request to an idle worker due to the workflow being locked. That isn t a major problem in itself; it can just try again later. However, in very large workflows, we found that it often worked its way down all the pending work requests one by one finding that each of them was locked, which was slow and also produced a huge amount of log noise. It now assumes that if a work request is locked, then it might as well skip other work requests in the same workflow until the next scheduler run. Between them, these changes reduced the number of locks typically being held on debusine.debian.net by about 80%: Lock graph

Worker refactoring The Debusine worker has always been partially asynchronous, but while it was actually executing a task - in other words, most of the time, at least in busy periods - it didn t respond to inbound websocket messages, causing spurious disconnections. We restructured the whole worker to be fully event-based. We also had to put quite a bit of effort into improving the path by which workers report work request completion, because if that hits a timeout then it can mean throwing away hours of work. We have some further improvements in mind, but for now we defer most of this work to a Celery task so that whole-workflow locks aren t on the critical path.

Database write volume One of our sysadmins observed that our database write volume was consistently very high. This was a puzzle, but for a long time we left that unexplored. Eventually we thought to ask PostgreSQL s own statistics, and we found a surprise:
debusine=> SELECT relname AS table_name,
debusine->        n_tup_ins AS inserts,
debusine->        n_tup_upd AS updates,
debusine->        n_tup_del AS deletes,
debusine->        (n_tup_ins + n_tup_upd + n_tup_del) AS total_dml
debusine-> FROM pg_stat_user_tables
debusine-> WHERE (n_tup_ins + n_tup_upd + n_tup_del) > 0
debusine-> ORDER BY total_dml DESC
debusine-> LIMIT 20;
              table_name                inserts    updates     deletes   total_dml
--------------------------------------+---------+------------+---------+------------
 db_collectionitem                      1418251   3578202388   3630143   3583250782
 db_token                                 15143     11212106     11389     11238638
 db_workrequest                          386196      6399071   1820500      8605767
 db_fileinartifact                      2783021      1837929   1663887      6284837
 django_celery_results_taskresult       1819301      1501623   1791656      5112580
 db_artifact                             960077      3340859    663890      4964826
 db_collectionitemmatchconstraint       1550457            0   2207486      3757943
 db_artifactrelation                    2229382            0   1363825      3593207
 db_fileupload                          1023400      1057036   1023346      3103782
 db_file                                1673194            0    970252      2643446
 db_fileinstore                         1411995            0    970259      2382254
 db_filestore                                 0      2381578         0      2381578
 django_session                          645423      1519880       531      2165834
 db_workrequest_dependencies             365877            0    936537      1302414
 db_worker                                18317       949280      9487       977084
 db_collection                            10061           85    177741       187887
 db_workerpooltaskexecutionstatistics     28721            0         0        28721
 db_workerpoolstatistics                   1640            0         0         1640
 db_workflowtemplate                        130          158       649          937
 db_identity                                 76          661         0          737
(20 rows)
Oh my - that s a lot of db_collectionitem updates and must surely be out of proportion with what we really need. Can we narrow that down by asking about the most recently-updated tuples?
debusine=> SELECT DISTINCT category
debusine-> FROM db_collectionitem
debusine-> WHERE id IN (
debusine->     SELECT id FROM db_collectionitem
debusine->     ORDER BY xmin::text::integer DESC LIMIT 10000
debusine-> );
           category
------------------------------
 debusine:historical-task-run
(1 row)
That might not be absolutely reliable, but it was certainly a hint. As per PostgreSQL s documentation, by default UPDATE always performs physical updates to every matching row regardless of whether the data has changed, and our code to expire old task history entries wasn t doing that properly. Once we knew where to look, it was easy to add some extra constraints. This reduced our mean write volume on debusine.debian.net from about 23 MB/s to about 3 MB/s, which had an immediate knock-on effect on our request failure rate: Disk write graph HTTP errors

Current state Our metrics indicate that things are a lot better now. We still have a few things to deal with, such as:
  • Some more performance fixes are on their way to fix some remaining cases where views are very slow or where file uploads from workers fail due to locks.
  • We have some changes in the works to revamp how work request changes propagate through workflows in a way that doesn t require so many heavyweight locks.
  • We have a number of monitoring and alerting improvements we d like to make, both for outcomes (things like slow Celery tasks) and possible root causes (database performance). We d also like to deploy some more modern observability tools; hunting for things using journalctl isn t terrible, but it s not really the state of the art.
  • We need to improve how we communicate to users when we re having operational problems, both informally (IRC, etc.) and on the site.
  • Retries don t always behave the way you d expect in workflows.
I hope this has been an interesting tour through the sorts of things that can go wrong in this kind of distributed system!

9 May 2026

Russell Coker: Bad Criticism of LLMs (not AI)

Discussion of AI systems seems to be dominated by fears of uncommon and unlikely threats. I think that we should be focusing more on real issues with LLMs and with society in general and put the most effort towards the biggest problems. It s Not AI True Artificial Intelligence [1] (IE a computer that has the mental capacity of a household pet) is something that I think can be developed, but it hasn t been developed and we don t have good plans for developing it. We seem to be a lot further away from achieving that goal than we were from landing on the moon in 1962 when JFK gave his historic speech. What we have is a variety of pattern recognition systems that can predict what fits into a pattern. The most well known type of Machine Learning (ML) is the Large Language Model (LLM) which means ChatGPT and similar systems which predict which text would be likely to come next and can make an essay from it. They can give interesting and useful output, but there is no thought behind it, it s just a better form of Eliza (the famous program from 1964 that simulates conversation by pattern matching) [2]. By analysing billions of documents, storing the data in a condensed mathematical way, and then using computation to extract from that record LLMs can produce output that is unfortunately considered by some people to be good enough to include in legal documents submitted to courts, university assignments, and many other documents. But they do so without even having the thinking ability of a mouse. To call current systems AIs without any significant qualifiers when criticising them is to concede the debate about the worth of such things. If we develop AIs that can actually think we will have to deal with the issues in the SciFi horror short story Lena by qntm [3]. The Bad Arguments Here is a list of some of the most unreasonable arguments I ve seen against AI which distract attention from real problems both related to AI and other problems in society. Suicide and Homicide Wikipedia has a page listing Deaths Linked to Chatbots [4] which right now has 16 entries from 2023 to Feb 2026. They are all tragedies and as a society we should try to prevent such things. But what I would like to see from the media is some analysis of overall trends, yes it gets people s attention when someone dies in an unusual way but we need to have attention paid to the more numerous deaths which are preventable. It has become a standard practice to give information on Lifeline in media referencing suicide, it would be good if they also developed a practice of mentioning the relative incidence of a problem when publishing an article about it. One of the many factors that cause more suicides than chatbots is school, Scientific American has an informative article from 2022 about the correlation between child suicide and school [5]. It is based on US statistics and shows that the lowest suicide rate is in July (a no-school month in the US) which has a rate of 2.3 per 100,000 person years. So if kids had a quality of life equivalent to July all year around then there would be 2.3 suicides per 100,000 kids every year while if they had a quality of life equivalent to a Monday in January or November it would be 3.9 suicides per 100,000 kids every year. The article states Any time I present these data to teachers, parents, principals or school administrators, they are shocked. This should be common knowledge. It is common knowledge to anyone who takes any notice of what happens in schools, but paying attention to serious problems is unpleasant, it s more fun to pretend that school is good for everyone. No parent wants to think that they sent their child to a place that was horrible, no teacher wants to think that they are part of a system that harms kids. The US CDC has an informative article about youth suicide [6] which documents it as the 3rd largest cause of death in the 14-18 age range fro 2021. This article was published in 2024 and based on statistics from 2023 and earlier. It notes significant differences in suicides, attempts, and persistent feelings of sadness or hopelessness which had girls at more than twice the rate of boys and LGBQ+ kids at more than twice the rate of heterosexual students. It seems obvious that misogyny and homophobia is correlated with suicide and that s something that could and should be addressed in schools. My state has a Safer Schools program [7] to try and alleviate the problems related to homophobia, but I expect that things are getting worse in the US in that regard. 39.7% of kids in US high schools had persistent feelings of sadness or hopelessness before LLMs became popular, school could and should be a happy time for the vast majority of kids but instead almost half of the kids don t enjoy it and a majority of girls and LGBQ+ kids don t. Having no mention of trans kids is a significant omission from that article, based on everything I ve heard from trans people I expect that their statistics would be even worse. One could argue that the small number of deaths inspired by use or misuse of LLMs is an indication of a larger number of people suffering in ways that don t result in death and don t get noticed. But I don t think that can compare to the fact that the majority of girls and LGBQ+ kids have persistent feelings of sadness or hopelessness in the current school system. Regarding homicide, the Australian Institute of Criminology has an article showing that in the 2003-2004 time period 49% of women who were killed were listed as a domestic argument [8], that s something that could and should be addressed. That article claimed 308 homicide victims in that time period which is larger than the world-wide death toll from LLMs but also less than 1/3 the death toll from car accidents in Australia. Australia has less than 0.4% of the world population, a fairly low homicide rate, and a number of homicides that vastly outnumbers all world homicides related to LLMs. I think it s great to address any cause of suicide or homicide, but devoting government resources and legislation towards very uncommon causes instead of things that happen every day is not a good strategy. It would be fine to address all factors leading to suicide, but problems with the school system have been a major factor for decades with little effort applied to fix it. Fraud and Other Crime There is evidence of criminals using LLMs to help prepare for crimes, the ability to generate large amounts of text quickly can be used for fraud and extortion. This is going to be a serious problem and we need structural changes to society to deal with it. There is an ongoing issue of scammers convincing older people that their child or other young relative is in trouble and a large amount of cash is required to address it. This sort of scam as well as the more well known Nigerian scams will probably become more common as the cost of running them decreases. This may be more of a problem for people in developing countries as currently a common scam business model is to have people in regions where wages are low (such as Pakistan for one who I spoke to) scamming people in relatively wealthy countries like Australia so an attack with a low probability of success is financially viable. Cheaper attacks will make less affluent victims financially viable to the scammers. While writing this post I received a financial scam phone call trying to get me to invest in SpaceX that was run by an AI chat system, I expect to receive more of them and this is something that needs to be dealt with via both technical measures and legislation. Do we have to accept less freedom and less anonymity in finances as a cost of reducing financial crime? Greater restrictions on the use of cash would make some crimes more difficult or less profitable for criminals. As a society I think we need to have a discussion about a balance between financial freedom and freedom from criminal exploitation, failing to have such a discussion is likely to lead to policies which don t work well. Also one thing that ML systems are good at is recognising patterns in data. Banks could scan all their transactions and look for patterns that correlate with fraud. They currently do this badly and do things like locking credit cards when someone goes to another country and spends money. They could do a better job of that and involve the police in cases of obvious fraud even when the customer doesn t realise that they are a victim. This isn t a reason to criticise AIs , it s a reason to plan defensive technology that matches the capabilities of attackers. As an aside I used to work for a company that was developing AI software to scan bank phone calls and allow banks to recognise employees who acted illegally. Unfortunately the Royal Commission into banking misconduct [9] didn t impose any penalties that gave the banks a financial reason to avoid criminal activity. Unemployment and Inequality There are many claims about AI systems making large numbers of jobs obsolete, some of them are outlandish such as the claims that all white-collar jobs will be obsolete in the near future. There are some reasonable claims like the ability to replace some mundane jobs. Replacing jobs that suck with computers, robots, and other machinery is a good thing! Very few people wish that they were working on a farm without a tractor. In 1900 it s estimated that between 60% and 70% of the world labour force worked in agriculture and 40% of the US labour force did so. Now it s something like 27% globally and between 1% and 3% in developed countries. Automated factories are also a good thing, it s best to avoid boring and dangerous work. The most plausible claims about job replacement from AI is jobs that involve analysing and summarising documents. One example that comes to mind is the worst kind of journalism where press releases from companies are massaged into the format of a feature article. I don t think anyone wants that sort of job and doing it with AI hopefully means no human has to sign their name to it. For work like programming few people will be directly replaced by AI but if people can do their work more efficiently while using it then less people are required. I don t think that any programmer likes the part of their job where they have to skim read long documents looking for a clue about how to solve a problem with a library or protocol. A LLM processing the document and finding the potentially useful things will take away the drudgery from the work and allow greater productivity. The trend in replacing people has been making people work longer. If you force all employees to work 60 hour weeks then that can theoretically allow hiring fewer people than having 40 hour weeks. For some work that applies but for skilled work it mostly doesn t as productivity and work quality on average drops when people work more than 40 hours in a week. Another trend for exploiting people is having a low minimum wage and making accommodation expensive so that many people need to work two jobs. What we need is legislation to restore the situation in the 70s where a single full time job was sufficient to provide for a family. The low minimum wage and high expenses for many things is a problem that s been slowly developing over the course of decades while being mostly ignored by journalists. If they could concentrate on the real issues that are hurting workers today they could incite political action to fix these problems. Academic Cheating There is no shortage of ways of cheating in school and university. There are people who are paid to write essays, mobile phones are used for cheating in exams, etc. Getting an AI to write essays makes it easier to cheat for the essay writing part but does so with lower quality and in a less stealthy way. What s the worst case scenario? That we have to change to oral exams for all university subjects? In the US the average annual price for tuition at a university is apparently $25,000, if each student had individually supervised assessment for their exams at a cost of $100 per hour it would make the degree cost 4% more. The cost of university in the US is unreasonably high and that s a problem that needs to be fixed, but a hypothetical case of increasing the price by 4% isn t going to be a major part of it. Weak Arguments Against AI Computer Security Attacks There have been many claims made that AI will break the security of all systems and cause the type of disruption that was previously predicted for year 2000. Bruce Schneier has written a good analysis of the issues including how AI can be used by both attackers and defenders [10], he doesn t have a strong conclusion on whether the net result will be good or bad but his article does make it clear that the result is not going to be a total disaster. While I was working on this post I read another post by Bruce Schneier that was significantly more negative about this issue [11]. While I still don t think this will destroy civilisation I found his other post convincing enough to move computer security from the bad argument section to the weak argument section. Spidering the Web to Death There are issues of bots from AI companies doing a bad job of trying to download all the Internet s content and using a lot of resources. When it was just the major search engines and the Wayback Machine doing it the load was small due to having a small number of organisations that were very good at the way they did it having evolved practices over many years. Now we have a lot of idiots doing it badly and repeatedly hitting generated content. This is really annoying but is something that we can deal with. Currently my blog and many other sites are hosted on a Hetzner server with a E3-1271 v3 CPU with 32G of RAM and there are occasions where more than half the CPU power is being used to service web requests from such systems. Even on the server bidding (renting servers previously used by other customers) Hetzner isn t offering systems so slow nowadays, the slowest they offer is about 20% faster than that. This is something that can be dealt with by spending a little more on hosting until the companies doing that go bankrupt. I m sure this is a serious problem for some people, but for most people it s not a big deal. Also hostile traffic on the Internet is something we have all had to deal with as a part of life since the mid to late 90s. RAM Prices The unreasonably high prices for RAM are annoying and hurt the development of useful computer projects. Big companies can afford it, even with current high prices and large quantities of RAM used for some servers it s still not significant. But it is a major issue for hobbyists and small projects. Things like setting up a dozen test VMs for FOSS development are now too expensive for many people who develop software in their spare time. But this is a temporary thing, if AI companies were to keep buying RAM at high rates for a few years companies would just manufacture more of it to meet demand. In some situations capitalism can work. Environmental Damage There are many people claiming that power used by data centers for AI will lead to environmental damage, using power and water when there isn t enough. The trend of computer hardware is to get smaller and faster. It hasn t been going as fast as it used to in many areas but it hasn t stopped either and it s an exponential trend. There has been an increase in data centers (DCs) for AI use as the use has been increasing faster than the hardware gets smaller. Eventually they will stop increasing faster than advances in hardware and software can match and the size of DCs will decrease. As the production of renewable energy is increases the environmental cost of energy hungry industries decreases. In a few years this won t be an issue anyone is bothered about. False Claims About Danger as PR Jamie McClelland makes an interesting claim that the AI companies are pushing dangers of AI as a method of PR [12]. That seems plausible and combined with the tendency of many journalists to just massage press releases from companies into articles could be the reason for a lot of the bad arguments against AI. Good Arguments Against AI Spam Everywhere I ve previously written about Communication and Hostile AIs [13]. I think that filling all communication channels with rubbish is a denial of service attack against society. In the past communication took some effort, even the simplest email that was directly targeted at the recipient took some human effort and that reduced it s frequency. I get a lot of spam saying something like I see your web site doesn t rank in the top for Google searches while my web site in fact rates well and the actor named Russell Coker is ranking below me, so I know that such spam hasn t had the minimum of human involvement. Now a spammer who wanted to do a better job could get an LLM written spam for every target so the message was specifically aimed at them and would take much longer to be recognised by a human as spam and would also avoid most anti-spam software. Searching for businesses used to be easy, the phone book had listings for them and there was a real cost to being in the book as well as humans actively trying to stop fraud. Creating fake web sites to get business isn t too difficult but it s also not trivial at the moment and such fake sites won t look complete. Now with LLMs it s possible to create hundreds of sites that have content and look reasonable without human involvement. Instead of the small number of suicides and homicides inspired by AI chat systems we should probably be concerned about people who need psychological or medical advice being misled by bogus web sites created as part of fraud campaigns. Imagine people searching for mental health assistance finding web sites run by cults who oppose psychology as a profession. Imagine people searching for basic medical advice such as how to cook a healthy meal getting sucked in to web sites that start sane and then lead people to Ivermectin as a universal medicine. LLMs have the potential to take spam from quick and simple attacks to large scale targeted fraud aimed at people and organisations that don t have the resources to defend against it. There have been many reports of CEO impersonation fraud against major corporations aiming to steal hundreds of thousands of dollars and fraud against individuals who are persuaded to get amounts like $50,000 to help a relative who is allegedly in a difficult situation. But if every corner store experienced the same type of attack that CEOs experience and if every child had someone trying to steal the pocket money in the same way that relatively wealthy people are being targeted now it would really change things. David Brin wrote an insightful and informative blog post about this focusing on how AI generated content is being allowed to destroy YouTube [14]. Deep Fakes There is some overlap between filling all communications channels with rubbish (fake news etc) and deep fake. Making a fake photo of a politician or celebrity to lobby for legislative changes is a real issue but it s not what most people think of when the term deep fake is used. Using photo and video faking targeting non-consenting people is a serious issue. It s not just fake porn (which is a major issue and will cause some suicides) as there are many other possibilities. Fake videos showing behaviour that justifies sacking people from their jobs is going to become an issue, for people in public facing positions even proof that the videos are fake won t necessarily help them. Will we find ourselves in a situation where every politician gets deep-fake porn made of them and the only people who run for public office are ones who are cool with that? Will positions of leadership in the technology industry be restricted to people who aren t bothered by having the most depraved fake porn made of them? The Justice System We have seen a lot of evidence of law enforcement and the court system based on bias leading to bad results. The Innocence Project attempts to correct that and it s web site documents some of the things that have gone wrong [15]. Using AI systems to do some of the work of law enforcement by training computers on the flawed results of current systems can entrench bias and also make it harder to spot. When determining whether someone should be considered a suspect or whether a prisoner should be eligible for parole the number of factors that a human can use is limited. But a computer can take many more factors into account so the issues of whether inappropriate factors are being used can be masked. Computers are also unable to explain decisions that they made and are also able to come up with better fake reasons. In the past there have been racist policies in the US about banks not lending to people living in suburbs where most houses were owned by non-white people, these policies were documented and the documents have become part of the historical record showing racist policies. If a LLM decides not to lend money to people based on mathematical correlations it determined based on historical banking practices it could assign negative weights to factors such as non-English names and implement the racism in a large array of numbers with no proof. The current cases of lawyers getting LLM systems to do some of their work and having their incompetence revealed when the computer generated work is shown to be ridiculously bad are amusing. But that is not the real problem. The real problems will start when the computers in police cars start flagging every car owned by a non-write person as having a probable cause for a drug stop. Technically Not Financial Fraud The majority of the ecosystem around AI is a financial scam [16]. There are companies and individuals doing good things with machine learning some of which is based on hardware and software developed as part of this ecosystem. But the majority of it has no plausible path to profits and a the future of it inevitably ends with some bankruptcies. There are circular flows of money that have the major cloud providers and NVidia looped in, when the values of these companies correct it will become apparent that they have all burned a lot of money keeping this running and all the senior people have got a share of it (the entire purpose of stock options is to allow senior people to suck money out of the company). Then every cloud provider will increase costs while under chapter 11 and all the companies that depend on them will pay whatever it takes. That includes all major companies and most governments. Unlike the dot-com boom and crash and the housing crash the coming financial crash will impact every company that we deal with and most governments. So the people in first-world countries will effectively be taxed to pay for this scam while the executives go party in Monaco. This may seem like an extreme claim but it all happened before with the dot com crash and the housing market crash. The CEO class has an ongoing practice of doing things that aren t crimes because they lobby (bribe) politicians to make them legal. So the current stock market shenanigans around AI don t seem to involve things that governments consider to be crimes. But any normal person might be surprised to learn that such things are legal and most people would vote for such things to be crimes if they had the opportunity. A global financial crisis is the least of the problems that seem likely to afflict society from AI systems. But it will be more immediately obvious when it happens which could be this year! Propaganda Creating art requires skills that the type of people who want to create propaganda tend to lack. AI technologies allow creating art that is based on mathematical models of actual art to the requirements of the person running the program. I have seen the term AI Fascism used to describe the use of AI to help authoritarian governments. I am dubious about whether it deserves that term and while every article I ve read about the topic has had some good points I thought that they were all weak points. But there are lots of ways that governments can abuse their populations without going full fascist. In the last century there were lots of truly terrible governments that didn t even make the top 10 of fascism. AI Sycophants Bruce Schneier wrote an informative blog post about AI Chatbots and Trust which focused on sycophantic chatbots [17]. We have seen a lot of evidence of terrible behaviour and stupid decisions from rich people due to having no negative consequences for bad choices. The vast majority of the history of kings concerns bad decisions made by such people. A future where middle class and poor people can make the same bad decisions as rich people wouldn t be good. Good Things About ML Machine Learning (abbreviated as ML) can do useful things. It s not just Large Language Models (LLMs) such as ChatGPT etc. There are also ML systems that can analyse images and other data sets. I have found ChatGPT to be very useful for making suggestions for improving blog posts. I don t get it to write anything just ask for suggestions. It has pointed out things that I missed such as when I didn t include the price when reviewing a car because the car in question was much more expensive than I will ever pay, the price wasn t relevant to me but would be to some readers. It has also made useful suggestions about structure of blog posts, repeating points, and having a good conclusion. It has some downsides which include trying to erase my voice from my writing, suggesting that the rhetorical question does email suck? is unprofessional. I have worked for a company that used ML systems to analyse driver performance and alert people if a driver is falling asleep, using a phone, or otherwise seems unable to drive safely. Their business model involved a human reviewing the images from the drivers the computer flagged and then determining who is actually doing the wrong thing. This seems a good use of the technology. I have also worked for a company that used ML systems to analyse the performance of bank employees and detect potentially fraudulent behaviour. Preventing crime seems to be clearly a good thing and in this case the manager of the employee in question would review the evidence to make sure that they weren t being falsely accused. Conclusion I don t think that the problems with managing the changes that so called AI is introducing are particularly new. An example of how society handles change that s worth considering is car safety. The seat belt first became mandatory for aeroplanes in some jurisdictions in 1928. The Model T Ford is widely regarded as the first vehicle to start a mass market for cars and it was released in 1925. So if society acted in a reasonable way then for the majority of mass market cars seat belts would have been a standard feature. However seat belts were first made compulsory in 1970 in Victoria Australia and there are still people who think that they are safer without seat belts! The delay in adoption of car seat belts is only one example of needless deaths caused by not taking reasonable measures for car safety but it s one that s easy to demonstrate and measure. The difference between past problems like car safety and the current problems of AI is that the AI problems will be more pervasive. Most of my history as a car driver and car passenger was in cars that are much less safe than cars made in the last 10 years. But partly through luck I ve never been in a serious crash so being in cars that wouldn t have given me a low probability of surviving a freeway speed crash didn t affect me. There is no possibility that through any combination of luck and skill someone could avoid the downsides of AI . If nothing else the results of elections will be affected and no-one can avoid that. As a society we really need to address the real issues related to AI which in some cases requires legislation.

8 May 2026

Russell Coker: Dirty Frag on Debian and SE Linux

Hot on the heels of the Copy Fail vulnerability [1] there is a new vulnerability Dirty Frag [2] (I linked to the Alma Linux page because it s the first one I saw and it explains things well). The Test System The test system was running kernel 6.19.14+deb14-amd64 and had the configuration after my last test of Copy Fail which was a default configuration with the following commands run:
semanage login -m -s user_u -r s0 __default__
restorecon -R -v -F /home
semanage login -m -s root -r s0 root
# logout and login again
semodule -X 100 -r unconfined
Strict Policy is Not Vulnerable I did a quick test on a Debian SE Linux system with a user running as user_t (which is often referred to as strict policy ) and got the following result:
test@testing1:~/t$ git clone https://github.com/V4bel/dirtyfrag.git && cd dirtyfrag && gcc -O0 -Wall -o exp exp.c -lutil && ./exp
Cloning into 'dirtyfrag'...
remote: Enumerating objects: 26, done.
remote: Counting objects: 100% (26/26), done.
remote: Compressing objects: 100% (20/20), done.
remote: Total 26 (delta 9), reused 23 (delta 6), pack-reused 0 (from 0)
Receiving objects: 100% (26/26), 5.83 MiB   11.47 MiB/s, done.
Resolving deltas: 100% (9/9), done.
dirtyfrag: failed (rc=1)
test@testing1:~/t/dirtyfrag$ ./exp 
dirtyfrag: failed (rc=1)
I checked the audit log and saw the following:
# audit2allow -al
#============= user_t ==============
allow user_t self:rxrpc_socket create;
allow user_t self:user_namespace create;
It seems that the rxrpc_socket access is the main thing. I did a search for domains permitted to use that class on a system without unconfined domains and saw the following:
# sesearch -A -c rxrpc_socket
allow daemon init_t:rxrpc_socket   getattr getopt ioctl read setopt write  ;
allow devicekit_disk_t domain:rxrpc_socket getattr;
allow sosreport_t domain:rxrpc_socket getattr;
allow sysadm_t domain:rxrpc_socket getattr;
This configuration doesn t appear to be vulnerable, at least to this form of the attack. Unconfined Domains I reinstalled the unconfined policy with the following command and assigned it to the user test2 with the following commands:
semodule -X 100 -i /usr/share/selinux/default/unconfined.pp.bz2
semanage login -a -s unconfined_u test2
restorecon -R -v -F /home/test2
I then tested the exploit as user test2 and got the following result:
test2@testing1:~$ git clone https://github.com/V4bel/dirtyfrag.git && cd dirtyfrag && gcc -O0 -Wall -o exp exp.c -lutil && ./exp
Cloning into 'dirtyfrag'...
remote: Enumerating objects: 26, done.
remote: Counting objects: 100% (26/26), done.
remote: Compressing objects: 100% (20/20), done.
remote: Total 26 (delta 9), reused 23 (delta 6), pack-reused 0 (from 0)
Receiving objects: 100% (26/26), 5.83 MiB   16.57 MiB/s, done.
Resolving deltas: 100% (9/9), done.
# id
uid=0(root) gid=0(root) groups=0(root) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
# 
The kernel message log had the following lines from the time of the attack:
[ 1310.861545] Initializing XFRM netlink socket
[ 1310.909048] alg: No test for authencesn(hmac(sha256),cbc(aes)) (authencesn(hmac-sha256-lib,cbc-aes-aesni))
[ 1310.909935] alg: No test for echainiv(authencesn(hmac(sha256),cbc(aes))) (echainiv(authencesn(hmac-sha256-lib,cbc-aes-aesni)))
[ 1318.353602] process 'su' launched '/bin/sh' with NULL argv: empty string added
Conclusion It seems that we will be getting a lot of these so running SE Linux users as user_t is the right thing to do for servers and multi user systems.

Amin Bandali: FFS code review with Protesilaos

In the recent weeks I've been engaging Prot as an Emacs coach to help with doing review passes over my upcoming ffs package as I work on polishing and documenting it in preparation for offering it for inclusion in GNU ELPA. Yesterday we had our second session focused on ffs, which I recorded and share publicly with everyone with Prot's permission, so that others can also benefit from Prot's insights and experience as we discuss various aspects of Emacs package development with the concrete example of ffs. Here is the video recording of our session: You can view or download the full-resolution video from the Internet Archive. I addressed most of Prot's feedback about ffs from our first session, and I'll be working on the changes we discussed in this session in the next days. In the last third of the video we switched topics to discuss a few Emacs-related tangents including adding a 'padding' effect for the mode line and its constructs, and distilling and separating the easily-reusable package-like parts of one's Emacs configuration from the actual configuration of those parts (e.g. the distinction of prot-lisp and prot-emacs-modules in Prot's Emacs configuration). For mode line padding, here is the snippet I'm using with Prot's doric-themes:
(doric-themes-with-colors
  (custom-set-faces
    (mode-line
     ((t :box (:line-width 6 :color ,bg-shadow-intense))))
    (mode-line-inactive
     ((t :box (:line-width 6 :color ,bg-shadow-subtle))))
    (mode-line-highlight
     ((t :box (:color ,bg-shadow-intense))))))
Take care, and so long for now.

7 May 2026

Reproducible Builds: Reproducible Builds in April 2026

Welcome to our April 2026 report from the Reproducible Builds project! Our reports outline what we ve been up to over the past month, highlighting items of news from elsewhere in the increasingly-important area of software supply-chain security. As ever, if you are interested in contributing to the Reproducible Builds project, please see the Contribute page on our website. In this month s report, we cover:

  1. Tor stateless relays and Reproducible Builds
  2. Civil Infrastructure Platform celebrates 10 years of supporting industrial grade Linux
  3. Reproducible Builds at LinuxFest NorthWest
  4. Reproducibility issues in Rust binaries that embed random bytes
  5. Distribution work
  6. Patches
  7. diffoscope development
  8. Documentation updates
  9. Misc news


Tor stateless relays and Reproducible Builds An interesting post was published on Tor Project blog by Osservatorio Nessuno OdV this month on stateless relays . These are stateless, diskless operating systems that are designed to be used as Tor exit relays. According to the post, which is titled A Server That Forgets: Exploring Stateless Relays:
For relay operators, this approach raises the security bar by enforcing better behaviors by design: [ ]
  1. Reproducibility. A system that doesn t change between reboots is easier to verify and, eventually, to reproduce and audit.
Furthermore, using a Trusted Platform Module (TPM), could allow for greater integrity in the future:
Transparency logs. Once you have a measured boot chain, you can publish it. A relay operator provides a recipe for a reproducible build; anyone can recompute the expected hash and verify it matches what the TPM reports. An append-only transparency log can make these attestations publicly auditable. The Tor community could run an independent monitor to track this across the relay fleet.

Civil Infrastructure Platform celebrates 10 years of supporting industrial grade Linux Congratulations to the Civil Infrastructure Platform (CIP) for reaching their 10-year anniversary last month. CIP has been a supporter of Reproducible Builds for many years, and we have collaborated on a number of technical issues that overlap. As Chris Lamb mentions in CIP s press release:
The collaboration between the Reproducible Builds project and CIP highlights a critical shift in how we approach industrial software. Through verifiability, CIP ensures that the open source foundation of our critical infrastructure is not only sustainable but also demonstrably secure. This commitment to transparency is vital for the trust and resilience required by critical systems over decades of operation.

Reproducible Builds at LinuxFest NorthWest Vagrant Cascadian and Chris Lamb hosted a table in the exposition hall at LinuxFest NorthWest 2026 this month in Bellingham, WA, USA, introducing many people to Reproducible Builds and answering questions both days of the conference. In addition, Vagrant presented Beyond Trusting Open Source Software on Sunday afternoon, exploring the intersection of Free/Open Source Software, Reproducible Builds and Bootstrappable builds, and how they all reinforce each other. Vagrant s slides are available online, including source code to build them reproducibly.

Reproducibility issues in Rust binaries that embed random bytes Reproducible Builds developer kpcyrd opened a ticket on the Rustsec issue tracker regarding binaries that deliberately inject random bytes into their binaries as a secret seed for a Hash Collision DoS mitigation. As kpcyrd notes in his message, this causes issues for reproducibility, and because the relevant end-user binaries are mostly distributed pre-compiled through package managers, those binaries (and by extension the secret seed) are public knowledge . kpcyrd goes on to note:
This is somewhat unique to Rust because Python/JavaScript doesn t compile binaries, and Go (to my knowledge) is too restrictive during build for any library to pull something like this.

Distribution work In Arch Linux this month, Robin Candau and Mark Hegreberg worked at adding a new repro tag/version to the Arch Linux Docker images providing a bit-for-bit reproducible image. Robin also shared a related announcement and implementation details on our mailing list. Arch Linux developer Robin Candau posted a blog post announcing that Arch Linux Now Has a Bit-for-Bit Reproducible Docker Image . Robin mentions one interesting caveat:
to ensure reproducibility, the pacman [package manager] keys have to be stripped from the image, meaning that pacman is not usable out of the box in this image. While waiting to find a suitable solution to this technical constraint, we are therefore providing this reproducible image under a dedicated tag as a first milestone. [ ]
The blog post was also discussed on Hacker News.
In Debian this month, 24 reviews of Debian packages were added, 7 were updated and 16 were removed this month adding to our knowledge about identified issues. Vagrant Cascadian performed Non-Maintainer Uploads (NMUs) in Debian for several packages with outstanding patches over a year old jakarta-jmeter, wxmplot, critcl, vcsh and magic-wormhole-transit-relay. In addition, Reproducible Builds developer Jochen Sprickerhof filed a bug against the APT package manager to request that APT should ignore [a] 0 epoch when downloading or installing with a version specifier . This is related to the special-case handling of the optional epoch prefix in Debian package version numbers.
In NixOS, Julien Malka presented Lila: Decentralized Build Reproducibility Monitoring for the Functional Package Management Model, a paper written together with Arnout Engelen at the Mining Software Repositories (MSR) ACM conference, where it was awarded the MSR 2026 FOSS Impact Award. Congratulations!
Lastly, in openSUSE, Michael Schroeder added reproducibility verification support in the Open Build Service [ ] and Bernhard M. Wiedemann posted another openSUSE monthly update for their reproducibility work there.

Patches The Reproducible Builds project detects, dissects and attempts to fix as many currently-unreproducible packages as possible. We endeavour to send all of our patches upstream where applicable or possible. This month, we wrote a large number of such patches, including:

diffoscope development diffoscope is our in-depth and content-aware diff utility that can locate and diagnose reproducibility issues. This month, Chris Lamb made a number of changes, including preparing and uploading versions, 316, 317 and 318 to Debian.
  • Chris Lamb:
    • Bump Standards-Version to 4.7.4. [ ]
    • Correct ordering of python3-guestfs architecture restrictions. [ ]
    • Limit python3-guestfs Build-Dependency to architectures that are not i386. [ ]
    • Try to fix PYPI_ID_TOKEN debugging. [ ]
  • Holger Levsen:
    • Add ppc64el to the list of python3-guestfs architecture whitelist. (Closes: #1132974). [ ]
In addition, Vagrant Cascadian updated diffoscope in GNU Guix to version 317.

Documentation updates Yet again, there were a number of improvements made to our website this month including:
  • Manuel Jacob:
    • Fix some minor wording issues on the Stable inputs page, and update information about the sorting behavior of GNU Make [ ].
    • On the Archives page, remove information about deterministic archives in historical Fedora versions [ ], add a note about .tar file portability [ ] and correct a section about .tar PAX headers [ ].
  • Mattia Rizzolo:
  • kpcyrd:
  • ktecho:

Misc news On our mailing list this month:
  • Timo Pohl posted our list inviting people to online group discussions with 4-6 participants each to talk about your perception of terms and requirements for reproducibility. As Timo notes:
    During our research of the existing literature, as well as my experience at the Reproducible Builds Summit 2025 in Vienna, we noticed that some of the terminology in the field is not used consistently across different groups of people, and that the precise meaning of some core terms like reproducibility of an artifact in itself is not uniform.
    As Timo mentions, the sessions will last roughly 90 minutes and will be rewarded with 50 per participant.
  • kpcyrd posted to the list asking for assistance with fixing an issue after updating the flake.lock file for their repro-env project.
  • Aman Sharma of the KTH Royal Institute of Technology, Sweden, posted to our list in order to share that Eric Cornelissen, a PhD student in KTH s CHAINS group, is maintaining an open-source project to monitor the reproducibility of GitHub Actions:
    The goal of the project is to assess whether GitHub Actions can be reproduced. Currently, it focuses on two types of Actions: JavaScript-based actions and Docker-based actions (composite actions are not considered). For JavaScript actions, the project rebuilds the distributed files and compares them bit-by-bit with the repository contents. For Docker actions, it rebuilds images from the Dockerfile and checks for semantic equivalence, using diffoci, across builds.


Finally, if you are interested in contributing to the Reproducible Builds project, please visit our Contribute page on our website. However, you can get in touch with us via:

5 May 2026

Amin Bandali: Emacs Chat with Sacha Chua

Yesterday I joined Sacha Chua for a new episode of her Emacs Chat podcast, where we talked about Emacs and life. I gave a quick tour of my Emacs configuration, discussing at length my configurations for EXWM (Emacs X Window Manager) among other topics like Emacs's facility for visually indicating buffer boundaries in the fringe by setting indicate-buffer-boundaries and my convenience configuration macros. The above video is provided with closed captions and the below transcript courtesy of Sacha with minor fixes and formatting by me. I've included some of Sacha's screenshots from our chat, you can see the rest on the episode's page on Sacha's blog. A few links from our chat: It was a lot of fun - thanks again for having me, Sacha! Take care, and so long for now.

Transcript

Thorsten Alteholz: My Debian Activities in April 2026

Debian LTS/ELTS This was my hundred-forty-second month that I did some work for the Debian LTS initiative, started by Raphael Hertzog at Freexian. During my allocated time I uploaded or worked on: I also did a week of front desk duties and started to work on backports of the cups CVEs. Debian Printing This month I uploaded a new upstream versions: Unfortunately the first upload of cups introduces a regression and another upload was needed to take care of a crash. The patch for one CVE also broke a test script, which is used by lots of printing packages in Debian. As a result some autopkgtest runs failed. This could be fixed as well and the only remaining issue that needs some more investigation is related to cups-pdf. This work is generously funded by Freexian! Debian Lomiri This month I continued to work on unifying packaging on Debian and Ubuntu. This makes it easier to work on those packages independent of the used platform. I also started working on two new packages: lomiri-radio-app and lomiri-fretboardtrainer-app This work is generously funded by Fre(i)e Software GmbH! Debian Astro This month I uploaded a new upstream version or a bugfix version of: Debian IoT This month I uploaded a new upstream version or a bugfix version of: Marcos Talau joined the Debian IoT group, welcome aboard. Debian Mobcom This month I uploaded a new upstream version or a bugfix version of: misc This month I uploaded a new upstream version or a bugfix version of:

4 May 2026

Russell Coker: Tower Servers and Resizable BAR

A feature on modern PCIe implementations is Resizable BAR AKA REBAR . This basically means that instead of allocating 256MB of address space for a PCIe device to have it s memory mapped the device can ask for more, the limit can be 4G with some hardware or the combination of motherboard and expansion card can support 64bit addressing to allow the entire memory space of a GPU to be mapped in one region. Directly mapping all the memory will be faster no matter how things work, but a combination of algorithms optimised for a flat memory layout and overheads from remapping can cause 90% of performance to be lost without REBAR support. Some GPUs (or maybe the software driving them) will even refuse to work without it. I believe that almost all hardware supporting DDR4 will support REBAR at a hardware level, but in many cases the BIOS doesn t support it. There are people who have reflashed a system BIOS to add REBAR support and there are options to use a modified UEFI boot loader to replace the code that is used for mapping the GPU memory. The systems I like to use are server grade tower systems with registered ECC RAM, after a few years they become quite cheap and still give decent performance while supporting large amounts of RAM. But many such systems that could support REBAR don t, presumably because the vendor doesn t have a great interest in supporting new uses of old hardware. Comparing the Name Brand Servers The HP Z640 and Z840 systems I m running date from 2014 and give good performance with replacement CPUs that are cheap on ebay, but they don t support REBAR without a flashed BIOS. The next release of those HP servers are the HP Z6 and Z8 Gen 4 systems from 2017 that have BIOS support for enabling REBAR. The Lenovo Thinkstation Px20 (P520, P920, etc) don t support REBAR which is especially disappointing as they were on sale from 2017 to 2022 and have decently fast CPUs. The replacement for the Px20 systems are the ones that are still on sale now and they seem likely to have REBAR support but won t be affordable on ebay. The Dell PowerEdge T440 and R740 systems (and presumably all their servers from 2017) don t support REBAR. There are no google hits for T550 and R750 systems from 2021, so presumably no complaints means that Dell servers from that era support it. But the T350 servers are junk and only take slow CPUs, and the T550 systems are brutally expensive. The Precision 5520 systems don t support it and newer Precision workstations will get expensive. It seems that HP is best for this. Which HP Workstation The Z2 G4 only supports 64G of RAM so isn t worth considering. The Z4 G4 is low end and comes in two variants. The one with i5/i7/i9 CPUs doesn t support ECC RAM so isn t suitable for me, and that probably means most Z4 G4 systems on the market. The upside is that apparently 2*6pin PCIe power cables is standard so any size GPU should work and there are 8 DIMM slots supporting up to 512G of RAM. There are 3 options for PSU, 490w for 0 GPUs, 750W for 2 (small) GPUs, and 1000W for up to 4 GPUs. The Z6 G4 has an option for a second CPU that almost no-one selects, that reduces the space for RAM so there s only 6 DIMM slots. But as there is no option for a Z6 without ECC RAM every one on offer will be good. The Z8 G4 is a nice dual socket system that I would not use for a serious GPU after my experience of my Z840 having a motherboard problem from a big GPU. The Z4 G4 is going for about $500 on ebay with the 750W PSU, that is more than I want to pay but not a lot more. In 6 months they could be going for $350 or so. There are hardly any Z6 G4 systems on offer and they are all well over $1000 so I m not considering them. Conclusion I need to poll the second hand sites for Z4 G4 systems and find one going cheap. One of those could be a good ML test machine for a while and then become a workstation once the faster CPUs (which are currently around $900) become cheap.

Russell Coker: Copy Fail on Debian and SE Linux

I have just learned of the Copy Fail kernel vulnerability [1] thanks to alexanderkjall@mastodon.social (who I have just followed on Mastodon and I recommend that you follow too). The question for me (after installing the patched kernel the systems of mine that are most exposed) is whether SE Linux would have stopped that. Basic Policy Analysis For the SE Linux policy analysis the alg_socket class is the one that is related to the exploit. So the following policy analysis command (run as non-root with policy copied to /tmp from a running system) shows what domains are allowed access on my current Debian development system:
$ sesearch -A -c alg_socket /tmp/policy.35 
allow NetworkManager_t NetworkManager_t:alg_socket   accept bind create read setopt write  ;
allow bluetooth_t bluetooth_t:alg_socket   accept append bind connect create getattr getopt ioctl listen read setattr setopt shutdown write  ;
allow daemon init_t:alg_socket   getattr getopt ioctl read setopt write  ;
allow devicekit_disk_t domain:alg_socket getattr;
allow lvm_t lvm_t:alg_socket   append bind connect create getattr getopt ioctl read setattr setopt shutdown write  ;
allow sosreport_t domain:alg_socket getattr;
allow sysadm_t domain:alg_socket getattr;
allow unconfined_domain_type domain:alg_socket   accept append bind connect create getattr getopt ioctl listen lock map name_bind read recvfrom relabelfrom relabelto sendto setattr setopt shutdown write  ;
The above is the same as on the Trixie release policy as these things aren t changed often. Below is from Debian/Bookworm which is the same apart from Bookworm not allowing lvm_t:
$ sesearch -A -c alg_socket /tmp/policy.33
allow NetworkManager_t NetworkManager_t:alg_socket   accept bind create read setopt write  ;
allow bluetooth_t bluetooth_t:alg_socket   accept append bind connect create getattr getopt ioctl listen read setattr setopt shutdown write  ;
allow daemon init_t:alg_socket   getattr getopt ioctl read setopt write  ;
allow devicekit_disk_t domain:alg_socket getattr;
allow sosreport_t domain:alg_socket getattr;
allow sysadm_t domain:alg_socket getattr;
allow unconfined_domain_type domain:alg_socket   accept append bind connect create getattr getopt ioctl listen lock map name_bind read recvfrom relabelfrom relabelto sendto setattr setopt shutdown write  ;
I checked every Debian policy back to when the alg_socket class was first added and found that the older versions had fewer domains granted access. The most recently added was bluetooth_t and the one before that was NetworkManager_t. The Risky Lines Of those allow statements the following are the risks: Unconfined Domains and the unconfined_domain_type Attribute When writing policy lines like the following line aren t generally considered a problem as unconfined domains are allowed full access to the system. However it can be an issue if you have a process in an unconfined domain without root access, which means a regular user login. Unfortunately this happens to be where this exploit and the default Debian SE Linux configuration intersect.
allow unconfined_domain_type domain:alg_socket   accept append bind connect create getattr getopt ioctl listen lock map name_bind read recvfrom relabelfrom relabelto sendto setattr setopt shutdown write  ;
The following shell code gets a list of unconfined domains which can be entered from user domains.
A=""
for n in $(seinfo -x -a unconfined_domain_type grep _t$) ; do
  A="$A ($n)"
done
A=$(echo $A sed -e s/^.//)
sesearch -T -s user_application_exec_domain -c process egrep "$A;"
Below is the output on a Debian/Trixie (Stable) system. So a confined user in the user_t domain could run an X server and try and get it to run the exploit code (which seems difficult) or running a Wine or Mono program from the Window manager in a Wayland environment.
type_transition user_t xserver_exec_t:process xserver_t;
type_transition user_wm_t mono_exec_t:process mono_t;
type_transition user_wm_t wine_exec_t:process wine_t;
type_transition user_wm_t xserver_exec_t:process xserver_t;
The issue of unconfined domains in SE Linux policy needs much more work. I ll write some blog posts about it later and the next release of Debian will be significantly better in this regard. Daemons that Have Access
allow NetworkManager_t NetworkManager_t:alg_socket   accept bind create read setopt write  ;
allow bluetooth_t bluetooth_t:alg_socket   accept append bind connect create getattr getopt ioctl listen read setattr setopt shutdown write  ;
Network Manager is something that can potentially be exploited by a desktop user as it has a large attack surface for the desktop interface. But as the vast majority of desktop user accounts are unconfined that s not an issue. This might be an issue for some restricted desktop PCs, maybe kiosk systems and those PCs that were being installed in prisons. The bluetooth_t domain is used by the bluetooth daemon that runs as root. While we generally are less concerned about a root process being exploited the daemon will handle some data from hostile sources and it could be used as an escalation attack by someone with a hostile Bluetooth device. These can t be exploited without another bug. The Lines that Aren t Problems The getattr Lines
allow devicekit_disk_t domain:alg_socket getattr;
allow sosreport_t domain:alg_socket getattr;
allow sysadm_t domain:alg_socket getattr;
The above getattr access isn t an issue as it just allows seeing process information, and it s also by privileged domains. The init_t Sockets
allow daemon init_t:alg_socket   getattr getopt ioctl read setopt write  ;
The daemon access to sockets inherited from init_t probably isn t a great idea, it s from the following section in init.te which is to allow socket activation for daemons, the comment is concerning in this context. Also socket_class_set is overly broad as without even inspecting the systemd source code I m pretty sure that far fewer than 1/3 of the 55 classes allowed by that rule are actually supported in systemd.
ifdef( init_systemd', 
        # Until systemd is fixed
        allow daemon init_t:socket_class_set   getattr getopt ioctl read setopt write  ;
But that s not really a problem as systemd has to just not create a socket of that type, if a hostile party can make systemd create such sockets then you have probably already lost. SE Linux Protection Overall SE Linux systems running confined users (kiosks and other confined GUI environments) will be protected barring a bug in Network Manager or the Bluetooth daemon as long as there is no Xserver installed (or the X server won t run scripts on startup), no Wine system installed, and no Mono. SE Linux servers and VMs will be protected against daemon issues as long as the daemon isn t unconfined. To convert the default login to user_t run the following commands:
semanage login -m -s user_u -r s0 __default__
restorecon -R -v -F /home
But it is still possible to access an unconfined domain from user_t (a topic I will address in detail in a future blog post). To remove unconfined entirely (not a task for novices or something to be done on in production without testing and planning) run the following commands:
semanage login -m -s root -r s0 root
# logout and login again
semodule -X 100 -r unconfined
Then a Debian/Trixie system running SE Linux will be safe against this attack even when running a vulnerable kernel. If you still want to use root as unconfined_t but still have untrusted shell users then run the following command to remove the easiest ways for users to run a program in an unconfined domain:
semodule -X 100 -r mono wine
Success and Failure Blocked by SE Linux Below is what happens on stdout/stderr when SE Linux blocks the exploit (tested with vulnerable Debian kernel 6.12.74+deb13+1-amd64):
test@testing1:~$ python3 ./copy_fail_exp.py 
Traceback (most recent call last):
  File "/home/test/./copy_fail_exp.py", line 9, in <module>
    while i<len(e):c(f,i,e[i:i+4]);i+=4
                   ~^^^^^^^^^^^^^^
  File "/home/test/./copy_fail_exp.py", line 5, in c
    a=s.socket(38,5,0);a.bind(("aead","authencesn(hmac(sha256),cbc(aes))"));h=279;v=a.setsockopt;v(h,1,d('0800010000000010'+'0'*64));v(h,5,None,4);u,_=a.accept();o=t+4;i=d('00');u.sendmsg([b"A"*4+c],[(h,3,i*4),(h,2,b'\x10'+i*19),(h,4,b'\x08'+i*3),],32768);r,w=g.pipe();n=g.splice;n(f,w,o,offset_src=0);n(r,u.fileno(),o)
  File "/usr/lib/python3.13/socket.py", line 233, in __init__
    _socket.socket.__init__(self, family, type, proto, fileno)
    ~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^PermissionError: [Errno 13] Permission denied
test@testing1:~$ su
Password:
When the attack is blocked by SE Linux there will be no messages in the kernel message log but the SE Linux audit log (typically stored in /var/log/audit/audit.log) will have lines like the following:
type=AVC msg=audit(1777803068.070:76): avc:  denied    create   for  pid=811 comm="python3" scontext=user_u:user_r:user_t:s0 tcontext=user_u:user_r:user_t:s0 tclass=alg_socket permissive=0
type=SYSCALL msg=audit(1777803068.070:76): arch=c000003e syscall=41 success=no exit=-13 a0=26 a1=80005 a2=0 a3=0 items=0 ppid=791 pid=811 auid=1000 uid=1000 gid=1000 euid=1000 suid=1000 fsuid=1000 egid=1000 sgid=1000 fsgid=1000 tty=pts0 ses=1 comm="python3" exe="/usr/bin/python3.13" subj=user_u:user_r:user_t:s0 key=(null)ARCH=x86_64 SYSCALL=socket AUID="test" UID="test" GID="test" EUID="test" SUID="test" FSUID="test" EGID="test" SGID="test" FSGID="test"
type=PROCTITLE msg=audit(1777803068.070:76): proctitle=707974686F6E33002E2F636F70795F6661696C5F6578702E7079
For that the :76 is the audit log entry number, the command ausearch -i -a 76 will interpret that message with the following output:
type=PROCTITLE msg=audit(05/03/26 10:11:08.070:76) : proctitle=python3 ./copy_fail_exp.py 
type=SYSCALL msg=audit(05/03/26 10:11:08.070:76) : arch=x86_64 syscall=socket success=no exit=EACCES(Permission denied) a0=alg a1=SOCK_SEQPACKET a2=ip a3=0x0 items=0 ppid=791 pid=811 auid=test uid=test gid=test euid=test suid=test fsuid=test egid=test sgid=test fsgid=test tty=pts0 ses=1 comm=python3 exe=/usr/bin/python3.13 subj=user_u:user_r:user_t:s0 key=(null) 
type=AVC msg=audit(05/03/26 10:11:08.070:76) : avc:  denied    create   for  pid=811 comm=python3 scontext=user_u:user_r:user_t:s0 tcontext=user_u:user_r:user_t:s0 tclass=alg_socket permissive=0 
When it Works Below is what happens when it works (again tested with Debian kernel 6.12.74+deb13+1-amd64):
test@testing1:~$ python3 ./copy_fail_exp.py 
# 
Here is the kernel log when the attack works:
[   30.441830] alg: No test for authencesn(hmac(sha256),cbc(aes)) (authencesn(hmac(sha256-avx2),cbc-aes-aesni))
[   30.447466] process 'su' launched '/bin/sh' with NULL argv: empty string added
When the Kernel Isn t Vulnerable If the kernel isn t vulnerable and SE Linux permits the attack (EG run from an unconfined domain) the following is seen on stdout/stderr:
$ python3 ./copy_fail_exp.py 
Password: 
su: Authentication failure
In that situation the kernel will log something like the following:
[   36.647023] alg: No test for authencesn(hmac(sha256),cbc(aes)) (authencesn(hmac-sha256-lib,cbc-aes-aesni))
This was tested on the Debian/Unstable kernel 6.19.13+deb14-amd64. Conclusion Run the following commands and then force all users to logout to make a Debian SE Linux system offering shell access reasonably safe against this bug. But also upgrade your kernel as soon as convenient because having multiple layers of protection is always good.
semanage login -m -s user_u -r s0 __default__
restorecon -R -v -F /home
semodule -X 100 -r mono wine
The GrapheneOS people are doing really good work on securing phones, I am most interested in Mobian (Debian on phones) but for people who have made different choices GrapheneOS is a good option. Here is the GrapheneOS statement on Copy Fail (they are not vulnerable to it) [3]. For people interested in running a secure Android build GrapheneOS is the best option. Their supported devices list shows Pixel 6 to Pixel 10 supported and Pixel 8 to Pixel 10a recommended [4]. In Australia Kogan sells refurbished Pixel 6 phones starting at $251 including delivery and refurbished Pixel 8 phones starting at $499 with First membership, they seem to have the cheapest Pixel phones. I want to make Debian more like Android in terms of security, but that s a topic for other blog posts. Here is the Debian page listing kernels that have been fixed against this exploit [5].

Russ Allbery: Review: Full Speed to a Crash Landing

Review: Full Speed to a Crash Landing, by Beth Revis
Series: Chaotic Orbits #1
Publisher: DAW
Copyright: August 2024
ISBN: 0-7564-1947-6
Format: Kindle
Pages: 153
Full Speed to a Crash Landing is a science fiction novella and the first of a series. Beth Revis made the New York Times bestseller list for an earlier series of young adult science fiction novels, but somehow I had not heard of her before this series. Ada Lamarr is a salvager. She picks up material from crashed or dead ships for resale. As the story opens, she has a large hole in the side of her ship, she's running out of oxygen, and the other ship nearby is refusing to answer her distress call. By the time they finally respond, there is barely enough time to get aboard before she is entirely out of air. Ada's first-person narration drops hints that she may not be entirely what she seems. But then, neither is the Halifax, so it's only fair. The captain of the Halifax treats Ada with a great deal of suspicion and wants her out of the way of their ongoing salvage operation. However, the captain does not appear to be entirely in charge. Ada is immediately struck by the mysterious Rian White, who seems to have some authority over their mission and is more thoughtful and calculating than the rest of the crew. He's also handsome, which doesn't hurt. I was tempted to keep writing about the plot, but given the short length of this book, I should stop there and let you enjoy the twists and turns for yourself. This is a fun science fiction action romp: lots of banter, lots of tense moments, and a cagey first-person protagonist with an irrepressible sense of humor and a knack for brazening her way through conversations. It's not long on world-building (there isn't enough room), but Revis works in enough details to be intriguing and to set up some interesting motivations. This is the sort of book that lives and dies by how much you like the protagonist, something that you will easily figure out by the end of an ebook sample if you're the sort of reader who uses those. Ada is irreverent, talkative, and very adroit at diverting attention (entertainingly) onto anything other than the critical piece of information other people are missing. If you want to, I suspect you could easily figure out most of what Ada is up to before the book reveals it explicitly. It's not that complicated, and the book isn't really trying to hide, although it doesn't give you all the necessary information in advance. Personally, I was happy to sit back and enjoy the ride. There is no romance in this book beyond frequent comments from Ada that she would have liked there to be a romance in this book under different circumstances, but I will be surprised if that romance doesn't show up later in the series. Ada and Rian are clearly being set up as a pair. I didn't like Rian as much, mostly because he's less memorable as a character, but he comes into his own in the appendices after the plot proper. I thought those concluding appendices were the best part of the novella and question the Kindle formatting decision to treat them like supplemental material. They purport to be a series of government memos, fill in a lot more of the backstory and world building, and have the best footnotes. Don't skip them! This isn't the sort of book that I am inspired to immediately push into everyone's hands, but it's a fast, well-paced story that delivered a few reading sessions of entertainment. I'm not sure the political philosophy in the background makes a lot of sense, but at least not a standard stereotype of current politics seen in so much science fiction. It's going to set up some interesting character conflict in later books. I'm certainly intrigued enough to keep reading. Recommended when you're in the mood for some fast-paced fun that's short and undemanding. Followed by How to Steal a Galaxy. Rating: 7 out of 10

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