diff options
| author |   stephen hemminger <shemminger@vyatta.com> | 2010-11-15 06:38:13 +0000 |
|---|---|---|
| committer |   David S. Miller <davem@davemloft.net> | 2010-11-15 11:13:17 -0800 |
| commit | b5ed54e94d324f17c97852296d61a143f01b227a (patch) | |
| tree | 2104d3cde24efc1145bc71beb4b61d79ed841132 /net/bridge/br_stp_bpdu.c | |
| parent | netdev: add rcu annotations to receive handler hook (diff) | |
| download | linux-dev-b5ed54e94d324f17c97852296d61a143f01b227a.tar.xz linux-dev-b5ed54e94d324f17c97852296d61a143f01b227a.zip | |
bridge: fix RCU races with bridge port
The macro br_port_exists() is not enough protection when only
RCU is being used. There is a tiny race where other CPU has cleared port
handler hook, but is bridge port flag might still be set.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/bridge/br_stp_bpdu.c')
| -rw-r--r-- | net/bridge/br_stp_bpdu.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/net/bridge/br_stp_bpdu.c b/net/bridge/br_stp_bpdu.c index 35cf27087b56..3d9a55d3822f 100644 --- a/net/bridge/br_stp_bpdu.c +++ b/net/bridge/br_stp_bpdu.c @@ -141,10 +141,6 @@ void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb, struct net_bridge *br; const unsigned char *buf; - if (!br_port_exists(dev)) - goto err; - p = br_port_get_rcu(dev); - if (!pskb_may_pull(skb, 4)) goto err; @@ -153,6 +149,10 @@ void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb, if (buf[0] != 0 || buf[1] != 0 || buf[2] != 0) goto err; + p = br_port_get_rcu(dev); + if (!p) + goto err; + br = p->br; spin_lock(&br->lock); |