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authorstephen hemminger <shemminger@vyatta.com>2010-11-15 09:38:13 +0300
committerDavid S. Miller <davem@davemloft.net>2010-11-15 22:13:17 +0300
commitb5ed54e94d324f17c97852296d61a143f01b227a (patch)
tree2104d3cde24efc1145bc71beb4b61d79ed841132 /net/bridge/br_stp_bpdu.c
parent61391cde9eefac5cfcf6d214aa80c77e58b1626b (diff)
downloadlinux-b5ed54e94d324f17c97852296d61a143f01b227a.tar.xz
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.c8
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);