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authorChristoph Lameter <cl@linux.com>2012-01-17 09:27:31 -0600
committerPekka Enberg <penberg@kernel.org>2012-02-06 12:24:13 +0200
commit66c4c35c6bc5a1a452b024cf0364635b28fd94e4 (patch)
tree75fa5528d28fdedde489e4d9ebc4a961aeecd6f0 /mm/slub.c
parent0ad9500e16fe24aa55809a2b00e0d2d0e658fc71 (diff)
downloadlwn-66c4c35c6bc5a1a452b024cf0364635b28fd94e4.tar.gz
lwn-66c4c35c6bc5a1a452b024cf0364635b28fd94e4.zip
slub: Do not hold slub_lock when calling sysfs_slab_add()
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>
Diffstat (limited to 'mm/slub.c')
-rw-r--r--mm/slub.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/slub.c b/mm/slub.c
index 5b915e86a9b0..bc7a8af24f16 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -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);