Bug 508341

Summary:	plasmashell crash on startup: "tcache_thread_shutdown(): unaligned tcache chunk detected"
Product:	[Plasma] plasmashell	Reporter:	fausto.nunez <fausto.nunez>
Component:	generic-crash	Assignee:	Plasma Bugs List <plasma-bugs>
Status:	RESOLVED UNMAINTAINED
Severity:	crash	Keywords:	drkonqi
Priority:	NOR
Version First Reported In:	6.3.6
Target Milestone:	1.0
Platform:	Debian stable
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:	https://crash-reports.kde.org/organizations/kde/issues/232669/events/9dab3c459a404cb4a4abb1c09614e4ce/
Attachments:	New crash information added by DrKonqi

Description fausto.nunez@mailbox.org 2025-08-16 13:58:45 UTC

Application: plasmashell (6.3.6)

ApplicationNotResponding [ANR]: false
Qt Version: 6.8.2
Frameworks Version: 6.13.0
Operating System: Linux 6.12.41+deb13-amd64 x86_64
Windowing System: Wayland
Distribution: Debian GNU/Linux 13 (trixie)
DrKonqi: 6.3.4 [CoredumpBackend]

-- Information about the crash:
I experience this crash as a coredump notification that appears when starting a KDE Plasma session. Other than the notification, there is no noticeable effect on the system: I can use it just fine.

From the backtrace, the crash seems to occur in glibc's malloc with the error "tcache_thread_shutdown(): unaligned tcache chunk detected".

System details:
- AMD Phoenix3 (Ryzen 7 8845HS) integrated graphics
- Mesa 25.0.7-2 with radeonsi driver
- Wayland session with kwin_wayland compositor 
- Debian 13 trixie (stable)
- Kernel 6.12.41+deb13-amd64

The crash can be reproduced sometimes.

-- Backtrace (Reduced):
#5  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at ./nptl/pthread_kill.c:44
#6  0x00007fc321c9e9ff in __pthread_kill_internal (threadid=<optimized out>, signo=6) at ./nptl/pthread_kill.c:89
#7  0x00007fc321c49cc2 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#8  0x00007fc321c324ac in __GI_abort () at ./stdlib/abort.c:73
#9  0x00007fc321c33291 in __libc_message_impl (fmt=fmt@entry=0x7fc321db532d "%s\n") at ../sysdeps/posix/libc_fatal.c:134


Reported using DrKonqi

Comment 1 fausto.nunez@mailbox.org 2025-08-16 13:58:46 UTC

Created attachment 184143 [details]
New crash information added by DrKonqi

DrKonqi auto-attaching complete backtrace.

Comment 2 fausto.nunez@mailbox.org 2025-08-16 14:12:00 UTC

I suppose this:

> Other than the notification, there is no noticeable effect on the system: I can use it just fine.

...is not exactly true: the Plasma shell does crash and restart, so I see e.g. my panel disappear and appear again, etc.

Comment 3 Bug Janitor Service 2025-08-16 14:33:41 UTC

Thank you for the bug report!

Debian advises users to not submit bugs upstream (https://www.debian.org/Bugs/Reporting), and Plasma 6.3.6 is no longer eligible for support or maintenance from KDE. It's possible that the issue exists only in Debian at this point.

Could you report the bug to Debian using the report bug utility (https://packages.debian.org/stable/utils/reportbug)? If necessary, the maintainer of the package will forward the bug upstream.
Thanks for understanding!

Thanks again!