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/netfilter | |
| parent | 61391cde9eefac5cfcf6d214aa80c77e58b1626b (diff) | |
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/netfilter')
| -rw-r--r-- | net/bridge/netfilter/ebtables.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c index a1dcf83f0d58..cbc9f395ab1e 100644 --- a/net/bridge/netfilter/ebtables.c +++ b/net/bridge/netfilter/ebtables.c @@ -128,6 +128,7 @@ ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb, const struct net_device *in, const struct net_device *out) { const struct ethhdr *h = eth_hdr(skb); + const struct net_bridge_port *p; __be16 ethproto; int verdict, i; @@ -148,13 +149,11 @@ ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb, if (FWINV2(ebt_dev_check(e->out, out), EBT_IOUT)) return 1; /* rcu_read_lock()ed by nf_hook_slow */ - if (in && br_port_exists(in) && - FWINV2(ebt_dev_check(e->logical_in, br_port_get_rcu(in)->br->dev), - EBT_ILOGICALIN)) + if (in && (p = br_port_get_rcu(in)) != NULL && + FWINV2(ebt_dev_check(e->logical_in, p->br->dev), EBT_ILOGICALIN)) return 1; - if (out && br_port_exists(out) && - FWINV2(ebt_dev_check(e->logical_out, br_port_get_rcu(out)->br->dev), - EBT_ILOGICALOUT)) + if (out && (p = br_port_get_rcu(out)) != NULL && + FWINV2(ebt_dev_check(e->logical_out, p->br->dev), EBT_ILOGICALOUT)) return 1; if (e->bitmask & EBT_SOURCEMAC) { |