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| author | Christoph Lameter <cl@linux.com> | 2012-01-17 09:27:31 -0600 |
|---|---|---|
| committer | Pekka Enberg <penberg@kernel.org> | 2012-02-06 12:24:13 +0200 |
| commit | 66c4c35c6bc5a1a452b024cf0364635b28fd94e4 (patch) | |
| tree | 75fa5528d28fdedde489e4d9ebc4a961aeecd6f0 /mm/slub.c | |
| parent | 0ad9500e16fe24aa55809a2b00e0d2d0e658fc71 (diff) | |
| download | lwn-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.c | 3 |
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); |