diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2009-09-03 22:38:59 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-09-15 10:37:24 -0700 |
| commit | 82b257c06a952cbda39a26012fd7e7978ac0b423 (patch) | |
| tree | 9225676bcf3eaa6d7a15ce70fc312bcfae576b8f | |
| parent | 9579d79f10d42ce275c94b945a3df2f5173d8041 (diff) | |
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.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/slub.c b/mm/slub.c index f0175b454c74..cbf856b5bc08 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2447,8 +2447,6 @@ 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) { @@ -2459,6 +2457,8 @@ 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); |