summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorEric Dumazet <eric.dumazet@gmail.com>2009-09-03 22:38:59 +0300
committerGreg Kroah-Hartman <gregkh@suse.de>2009-09-15 10:45:24 -0700
commite8f23f08a0dbfbaf5e95fa77a12c8cb2b1bd97e7 (patch)
tree7c0d382c59fd283d35e4fefc75a00be2a6b28f55
parent6c135b4e133017a8aeef1534107ee4b1f11d3265 (diff)
downloadlinux-stable-e8f23f08a0dbfbaf5e95fa77a12c8cb2b1bd97e7.tar.gz
linux-stable-e8f23f08a0dbfbaf5e95fa77a12c8cb2b1bd97e7.tar.bz2
linux-stable-e8f23f08a0dbfbaf5e95fa77a12c8cb2b1bd97e7.zip
slub: Fix kmem_cache_destroy() with SLAB_DESTROY_BY_RCU
commit d76b1590e06a63a3d8697168cd0aabf1c4b3cb3a upstream. kmem_cache_destroy() should call rcu_barrier() *after* kmem_cache_close() and *before* sysfs_slab_remove() or risk rcu_free_slab() being called after kmem_cache is deleted (kfreed). rmmod nf_conntrack can crash the machine because it has to kmem_cache_destroy() a SLAB_DESTROY_BY_RCU enabled cache. Reported-by: Zdenek Kabelac <zdenek.kabelac@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--mm/slub.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/slub.c b/mm/slub.c
index 253016d3cb4c..0b95a6cc8a41 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2490,8 +2490,6 @@ static inline int kmem_cache_close(struct kmem_cache *s)
*/
void kmem_cache_destroy(struct kmem_cache *s)
{
- if (s->flags & SLAB_DESTROY_BY_RCU)
- rcu_barrier();
down_write(&slub_lock);
s->refcount--;
if (!s->refcount) {
@@ -2502,6 +2500,8 @@ void kmem_cache_destroy(struct kmem_cache *s)
"still has objects.\n", s->name, __func__);
dump_stack();
}
+ if (s->flags & SLAB_DESTROY_BY_RCU)
+ rcu_barrier();
sysfs_slab_remove(s);
} else
up_write(&slub_lock);