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slub: Do not hold slub_lock when calling sysfs_slab_add()

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sysfs_slab_add() calls various sysfs functions that actually may
end up in userspace doing all sorts of things.

Release the slub_lock after adding the kmem_cache structure to the list.
At that point the address of the kmem_cache is not known so we are
guaranteed exlusive access to the following modifications to the
kmem_cache structure.

If the sysfs_slab_add fails then reacquire the slub_lock to
remove the kmem_cache structure from the list.

Cc: <stable@vger.kernel.org>	# 3.3+
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>
This commit is contained in:
Christoph Lameter 2012-01-17 09:27:31 -06:00 committed by Pekka Enberg
parent 0ad9500e16
commit 66c4c35c6b
1 changed files with 2 additions and 1 deletions
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3
mm/slub.c
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@ -3937,13 +3937,14 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size,
if (kmem_cache_open(s, n,
size, align, flags, ctor)) {
list_add(&s->list, &slab_caches);
up_write(&slub_lock);
if (sysfs_slab_add(s)) {
down_write(&slub_lock);
list_del(&s->list);
kfree(n);
kfree(s);
goto err;
}
up_write(&slub_lock);
return s;
}
kfree(n);