Hello, Crash is currently not working when used to inspect the system on Debian 12. It returns "crash: cannot set context for pid: 498070" and then crashes. I identified the following commit solves the problem. Fix failure of gathering task table on Linux 6.5-rc1 and later https://github.com/crash-utility/crash/commit/88580068b7dd96bf679c82bdc05e146968ade10c I built different versions of crash version 8 from source and with the commit above applied, it works fine. Without it, the utility crashes and makes it non-functional. Default crash installed from the package. ``` user@debian:~$ sudo crash ~/vmlinux-6.1.0-50-amd64 crash 8.0.2 ... [snip GDB header] ... For help, type "help". Type "apropos word" to search for commands related to "word"... crash: cannot set context for pid: 498070 Segmentation fault user@debian:~$ ``` Crash 8 version built from commit 88580068b7dd96bf679c82bdc05e146968ade10c. ``` user@debian:~/crash$ sudo ./crash ~/vmlinux-6.1.0-50-amd64 crash 8.0.3++ ... [snip GDB header] ... For help, type "help". Type "apropos word" to search for commands related to "word"... KERNEL: /home/user/vmlinux-6.1.0-50-amd64 DUMPFILE: /proc/kcore CPUS: 4 DATE: Fri Jul 10 21:59:47 -03 2026 UPTIME: 01:22:49 LOAD AVERAGE: 3.22, 2.72, 2.32 TASKS: 215 NODENAME: debian RELEASE: 6.1.0-50-amd64 VERSION: #1 SMP PREEMPT_DYNAMIC Debian 6.1.176-1 (2026-07-02) MACHINE: x86_64 (2711 Mhz) MEMORY: 2 GB PID: 456429 COMMAND: "crash" TASK: ffff8b58c5eb3380 [THREAD_INFO: ffff8b58c5eb3380] CPU: 1 STATE: TASK_RUNNING (ACTIVE) crash> quit user@debian:~/crash$ git log commit 88580068b7dd96bf679c82bdc05e146968ade10c (HEAD) Author: Kazuhito Hagio <k-hagio-ab@nec.com> Date: Fri Jun 23 16:34:35 2023 +0900 Fix failure of gathering task table on Linux 6.5-rc1 and later Kernel commit b69f0aeb0689 ("pid: Replace struct pid 1-element array with flex-array") changed pid.numbers[1] to pid.numbers[]. With this, the size of struct pid does not contain the size of struct upid: (gdb) ptype /o struct pid /* offset | size */ type = struct pid { /* 0 | 4 */ refcount_t count; ... /* 96 | 0 */ struct upid numbers[]; ^^^^ ^^^ /* total size (bytes): 96 */ } ^^^^ As a result, in refresh_xarray_task_table(), crash does not read the data of pid.numbers[0].ns and cannot gather the task table correctly. $ crash vmlinux vmcore ... WARNING: active task ffff936992ad0000 on cpu 1 not found in PID hash ... crash> ps -S RU: 9 crash> Increase the size of reading struct pid by SIZE(upid) in this case. Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com> ... user@debian:~/crash$ ``` Crash 8 version built from commit 7750e61fdb2a083f26156a5338aa2ebe26447f3f (parent of fix). ``` user@debian:~/crash$ sudo ./crash ~/vmlinux-6.1.0-50-amd64 crash 8.0.3++ ... [snip GDB header] ... For help, type "help". Type "apropos word" to search for commands related to "word"... crash: cannot set context for pid: 496536 Segmentation fault user@debian:~/crash$ git log commit 7750e61fdb2a083f26156a5338aa2ebe26447f3f (HEAD) Author: Kazuhito Hagio <k-hagio-ab@nec.com> Date: Thu Jun 22 16:09:07 2023 +0900 Support module memory layout change on Linux 6.4 Support module memory layout change on Linux 6.4 by kernel commit ac3b43283923 ("module: replace module_layout with module_memory") [1]. Without the patch, crash cannot even start a session with an error message like this: crash: invalid structure member offset: module_core_size FILE: kernel.c LINE: 3787 FUNCTION: module_init() [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ac3b43283923 Signed-off-by: Kazuhito Hagio <k-hagio-ab@nec.com> ... user@debian:~/crash$ ``` I recommend backporting commit 88580068b7dd96bf679c82bdc05e146968ade10c to make crash utility functional by default on Debian 12.
Confirmed. Thanks for the report. I wonder though why this bug report triggers an auto-removal of crash 9.0.2+~16.3-1 from testing?? Hopefully this update defers that... ...Juerg
On Fri, 07 Aug 2026 10:32:05 +0000 Juerg Haefliger <juergh@proton.me> wrote: > Confirmed. Thanks for the report. > > I wonder though why this bug report triggers an auto-removal of crash > 9.0.2+~16.3-1 from testing?? > > Hopefully this update defers that... > > ...Juerg > > > Hello Juerg, That was the first time I had reported a bug to Debian, and I don't know why I didn't receive your message. Sorry for the delay. Where do I see the auto-removal? Was it something that I did when I reported the bug? Thanks for fixing the bug, I'll test it as soon as possible.
figure out BTS :-) I fiddled with it and the autoremoval is gone now. FTR, it showed up here (in the action needed list): https://tracker.debian.org/pkg/crash FYI, I've uploaded a candidate to [1] and [2]. Can you grab the binary deb from [2] and give it a whirl? Thanks ...Juerg [1] https://mentors.debian.net/ [2] https://people.canonical.com/~juergh/bug1141862/
On Fri, 21 Aug 2026 08:40:25 +0000 Juerg Haefliger <juergh@proton.me> wrote: > > why I didn't receive your message. Sorry for the delay. Where do I see > > the auto-removal? Was it something that I did when I reported the bug? > > No, you didn't do anything wrong. I'm also new to this and still try to > figure out BTS :-) I fiddled with it and the autoremoval is gone now. > > FTR, it showed up here (in the action needed list): > https://tracker.debian.org/pkg/crash > > FYI, I've uploaded a candidate to [1] and [2]. Can you grab the binary deb > from [2] and give it a whirl? > > Thanks > ...Juerg > > [1] https://mentors.debian.net/ > [2] https://people.canonical.com/~juergh/bug1141862/ Hello Juerg, First, my apologies for the delay. I haven't checked if you pushed it to the official repository yet, but I tested the .deb package you provided and it fixes the issue. Thank you! Before $ uname -a Linux debian 6.1.0-52-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.180-1 (2026-08-03) x86_64 GNU/Linux $ apt-cache show crash Package: crash Version: 8.0.2-1 ... $ sudo crash vmlinux-6.1.0-52-amd64 [sudo] password for user: crash 8.0.2 ... crash: cannot set context for pid: 3754 Segmentation fault $ After $ sudo dpkg -i crash_8.0.2-1.1_amd64.deb (Reading database ... 80437 files and directories currently installed.) Preparing to unpack crash_8.0.2-1.1_amd64.deb ... Unpacking crash (8.0.2-1.1) over (8.0.2-1) ... Setting up crash (8.0.2-1.1) ... Processing triggers for man-db (2.11.2-2) ... $ apt-cache show crash Package: crash Status: install ok installed Priority: optional Section: utils Installed-Size: 11942 Maintainer: Troy Heber <troyh@debian.org> Architecture: amd64 Version: 8.0.2-1.1 ... $ sudo crash vmlinux-6.1.0-52-amd64 crash 8.0.2 Copyright (C) 2002-2022 Red Hat, Inc. ... KERNEL: vmlinux-6.1.0-52-amd64 [TAINTED] DUMPFILE: /proc/kcore CPUS: 4 DATE: Sat Sep 5 14:58:54 -03 2026 UPTIME: 00:22:46 LOAD AVERAGE: 0.12, 0.24, 0.13 TASKS: 213 NODENAME: debian RELEASE: 6.1.0-52-amd64 VERSION: #1 SMP PREEMPT_DYNAMIC Debian 6.1.180-1 (2026-08-03) MACHINE: x86_64 (2712 Mhz) MEMORY: 2 GB PID: 3811 COMMAND: "crash" TASK: ffff888020343380 [THREAD_INFO: ffff888020343380] CPU: 0 STATE: TASK_RUNNING (ACTIVE) crash> ps PID PPID CPU TASK ST %MEM VSZ RSS COMM 0 0 0 ffffffff82a1aa40 RU 0.0 0 0 [swapper/0] > 0 0 1 ffff888004ab99c0 RU 0.0 0 0 [swapper/1] > 0 0 2 ffff888004abb380 RU 0.0 0 0 [swapper/2] 0 0 3 ffff888004abcd40 RU 0.0 0 0 [swapper/3] 1 0 0 ffff888004a33380 IN 0.6 167776 12104 systemd ... crash> files PID: 3811 TASK: ffff888020343380 CPU: 0 COMMAND: "crash" ROOT: / CWD: /home/user FD FILE DENTRY INODE TYPE PATH 0 ffff888009ef5800 ffff888016df7e40 ffff88800ac5a300 CHR /dev/pts/1 1 ffff888009ef5800 ffff888016df7e40 ffff88800ac5a300 CHR /dev/pts/1 2 ffff888009ef5800 ffff888016df7e40 ffff88800ac5a300 CHR /dev/pts/1 ... 17 ffff888010c90a00 ffff88804a518cc0 ffff88801894a080 FIFO crash>