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| author | Christoph Lameter <cl@linux.com> | 2012-01-17 09:27:31 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-04-02 09:27:20 -0700 |
| commit | 295706896259f338b1c69e0b3a293c77beb372c0 (patch) | |
| tree | 9357f13b4386ff44bef75103a9ba455c76285ca9 | |
| parent | a1bdf3aaf88552ce9820f90bae9d6f7e44831c60 (diff) | |
| download | lwn-295706896259f338b1c69e0b3a293c77beb372c0.tar.gz lwn-295706896259f338b1c69e0b3a293c77beb372c0.zip | |
slub: Do not hold slub_lock when calling sysfs_slab_add()
commit 66c4c35c6bc5a1a452b024cf0364635b28fd94e4 upstream.
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.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 0d0901ebaea2..10ab2335e2ea 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3439,13 +3439,14 @@ 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); |