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| author | Oleg Nesterov <[email protected]> | 2025-06-13 17:26:50 +0000 |
|---|---|---|
| committer | Linus Torvalds <[email protected]> | 2025-06-13 17:55:49 +0000 |
| commit | f90fff1e152dedf52b932240ebbd670d83330eca (patch) | |
| tree | 82091a26b42acc31e985cad32197d08485fd07a3 /lib/crypto/mpi/mpi-mul.c | |
| parent | Merge tag 'trace-v6.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/... (diff) | |
| download | kernel-f90fff1e152dedf52b932240ebbd670d83330eca.tar.gz kernel-f90fff1e152dedf52b932240ebbd670d83330eca.zip | |
posix-cpu-timers: fix race between handle_posix_cpu_timers() and posix_cpu_timer_del()
If an exiting non-autoreaping task has already passed exit_notify() and
calls handle_posix_cpu_timers() from IRQ, it can be reaped by its parent
or debugger right after unlock_task_sighand().
If a concurrent posix_cpu_timer_del() runs at that moment, it won't be
able to detect timer->it.cpu.firing != 0: cpu_timer_task_rcu() and/or
lock_task_sighand() will fail.
Add the tsk->exit_state check into run_posix_cpu_timers() to fix this.
This fix is not needed if CONFIG_POSIX_CPU_TIMERS_TASK_WORK=y, because
exit_task_work() is called before exit_notify(). But the check still
makes sense, task_work_add(&tsk->posix_cputimers_work.work) will fail
anyway in this case.
Cc: [email protected]
Reported-by: Benoît Sevens <[email protected]>
Fixes: 0bdd2ed4138e ("sched: run_posix_cpu_timers: Don't check ->exit_state, use lock_task_sighand()")
Signed-off-by: Oleg Nesterov <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Diffstat (limited to 'lib/crypto/mpi/mpi-mul.c')
0 files changed, 0 insertions, 0 deletions