diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-11-09 17:51:23 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-12-09 13:40:07 -0500 |
| commit | 0be0e5758dbdf3f61378b5d17d00363f92e93bae (patch) | |
| tree | 3c199964648d3d26b653a05f410082d9d2723a2d | |
| parent | 0861d012ecff07b74a8c6ecfda04bb1737831e09 (diff) | |
net: fix a race in dst_release()
[ Upstream commit d69bbf88c8d0b367cf3e3a052f6daadf630ee566 ]
Only cpu seeing dst refcount going to 0 can safely
dereference dst->flags.
Otherwise an other cpu might already have freed the dst.
Fixes: 27b75c95f10d ("net: avoid RCU for NOCACHE dst")
Reported-by: Greg Thelen <gthelen@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/core/dst.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/dst.c b/net/core/dst.c index c0e021871df8..01f9980af86e 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -283,7 +283,7 @@ void dst_release(struct dst_entry *dst) newrefcnt = atomic_dec_return(&dst->__refcnt); WARN_ON(newrefcnt < 0); - if (unlikely(dst->flags & DST_NOCACHE) && !newrefcnt) + if (!newrefcnt && unlikely(dst->flags & DST_NOCACHE)) call_rcu(&dst->rcu_head, dst_destroy_rcu); } } |