diff options
| author | JianJhen Chen <kchen@synology.com> | 2019-01-06 11:28:13 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-22 21:40:30 +0100 |
| commit | 54cbcff82d5eb7fd00d964a6c534362735460d19 (patch) | |
| tree | c55fb1b6f2b415f982e7b9743ce53e2e1432b3bd /net/bridge | |
| parent | c0e1392e37e1f4f1e325a0a8ad75e5832f168450 (diff) | |
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_hooks.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c index 37278dc280eb..e07a7e62c705 100644 --- a/net/bridge/br_netfilter_hooks.c +++ b/net/bridge/br_netfilter_hooks.c @@ -278,7 +278,7 @@ int br_nf_pre_routing_finish_bridge(struct net *net, struct sock *sk, struct sk_ struct nf_bridge_info *nf_bridge = nf_bridge_info_get(skb); 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(net, sk, skb); |