diff options
| author | JianJhen Chen <kchen@synology.com> | 2019-01-06 06:28:13 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-26 11:44:25 +0300 |
| commit | 23009dc3d4ff659739659c10f386a10af628b59f (patch) | |
| tree | e97ddc9b58d551d673722e014bdbabaa9949bf7f /net/bridge | |
| parent | 8c871bdbd02f71e31961dce3a70e77d450765f16 (diff) | |
| download | linux-23009dc3d4ff659739659c10f386a10af628b59f.tar.xz | |
net: bridge: fix a bug on using a neighbour cache entry without checking its state
[ Upstream commit 4c84edc11b76590859b1e45dd676074c59602dc4 ]
When handling DNAT'ed packets on a bridge device, the neighbour cache entry
from lookup was used without checking its state. It means that a cache entry
in the NUD_STALE state will be used directly instead of entering the NUD_DELAY
state to confirm the reachability of the neighbor.
This problem becomes worse after commit 2724680bceee ("neigh: Keep neighbour
cache entries if number of them is small enough."), since all neighbour cache
entries in the NUD_STALE state will be kept in the neighbour table as long as
the number of cache entries does not exceed the value specified in gc_thresh1.
This commit validates the state of a neighbour cache entry before using
the entry.
Signed-off-by: JianJhen Chen <kchen@synology.com>
Reviewed-by: JinLin Chen <jlchen@synology.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/bridge')
| -rw-r--r-- | net/bridge/br_netfilter.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index f076a8ede00b..6aec6b264f8e 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -287,7 +287,7 @@ static int br_nf_pre_routing_finish_bridge(struct sk_buff *skb) if (neigh) { int ret; - if (neigh->hh.hh_len) { + if ((neigh->nud_state & NUD_CONNECTED) && neigh->hh.hh_len) { neigh_hh_bridge(&neigh->hh, skb); skb->dev = nf_bridge->physindev; ret = br_handle_frame_finish(skb); |