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ipc/sem: do not sleep with a spin lock held 

We can't call kvfree() with a spin lock held, so defer it.

Link: https://lkml.kernel.org/r/20211223031207.556189-1-chi.minghao@zte.com.cn
Fixes: fc37a3b8b4 ("[PATCH] ipc sem: use kvmalloc for sem_undo allocation")
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Yang Guang <cgel.zte@gmail.com>
Cc: Davidlohr Bueso <dbueso@suse.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Cc: Vasily Averin <vvs@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Minghao Chi 2022-02-03 20:49:33 -08:00 committed by Linus Torvalds
parent 314c459a6f
commit 520ba72406
1 changed files with 2 additions and 2 deletions
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4
ipc/sem.c
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@ -1964,6 +1964,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
*/ */
un = lookup_undo(ulp, semid); un = lookup_undo(ulp, semid);
if (un) { if (un) {
spin_unlock(&ulp->lock);
kvfree(new); kvfree(new);
goto success; goto success;
} }
@ -1976,9 +1977,8 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid)
ipc_assert_locked_object(&sma->sem_perm); ipc_assert_locked_object(&sma->sem_perm);
list_add(&new->list_id, &sma->list_id); list_add(&new->list_id, &sma->list_id);
un = new; un = new;
success:
spin_unlock(&ulp->lock); spin_unlock(&ulp->lock);
success:
sem_unlock(sma, -1); sem_unlock(sma, -1);
out: out:
return un; return un;