Re: Please consider fb3bbcfe344e ("exit: change the release_task() paths to call flush_sigqueue() lockless") for 5.10.y, 5.15.y, 6.1.y, 6.6.y, and 6.12.y

[Sasha Levin]

On Thu, Jul 09, 2026 at 10:31:20PM -0400, Michael Bommarito wrote:
> Upstream commit: fb3bbcfe344e64a46574a638b051ffd78762c12d
> Subject: exit: change the release_task() paths to call flush_sigqueue() lockless
>
> Backport note:
> The mechanical check above reports whether the upstream diff applies to
> each listed branch as-is. In this refresh, the upstream diff applies
> cleanly to the file snapshots for all requested series.

The diff applies cleanly, but it isn't safe on any of the requested
branches. The commit's correctness depends on the v6.13+ posix-timer
rework (6017a158beb1 "posix-timers: Embed sigqueue in struct k_itimer"
and friends), after which timer deletion no longer clears
SIGQUEUE_PREALLOC or frees tmr->sigq behind the exiting task's back.

-- 
Thanks,
Sasha