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 14:03:13 -0500 |
| commit | e6fac8c7fff3d816729ad16327837ba3216d48c9 (patch) | |
| tree | ae47301b16d7e74b7983d24cb27745bc67c4c132 /net | |
| parent | 97c28b72a5ceb80e193910cbed068b44c951bd94 (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>
Diffstat (limited to 'net')
| -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 e956ce6d1378..f8db4032d45a 100644 --- a/net/core/dst.c +++ b/net/core/dst.c @@ -285,7 +285,7 @@ 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); } } |