diff options
| author | stephen hemminger <shemminger@vyatta.com> | 2010-11-15 07:38:13 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-11-15 20:13:17 +0100 |
| commit | b5ed54e94d324f17c97852296d61a143f01b227a (patch) | |
| tree | 2104d3cde24efc1145bc71beb4b61d79ed841132 /net/bridge/br_netlink.c | |
| parent | netdev: add rcu annotations to receive handler hook (diff) | |
| download | linux-b5ed54e94d324f17c97852296d61a143f01b227a.tar.xz linux-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_netlink.c')
| -rw-r--r-- | net/bridge/br_netlink.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c index 4a6a378c84e3..e3de0a428f5d 100644 --- a/net/bridge/br_netlink.c +++ b/net/bridge/br_netlink.c @@ -119,11 +119,13 @@ static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) idx = 0; for_each_netdev(net, dev) { + struct net_bridge_port *port = br_port_get(dev); + /* not a bridge port */ - if (!br_port_exists(dev) || idx < cb->args[0]) + if (!port || idx < cb->args[0]) goto skip; - if (br_fill_ifinfo(skb, br_port_get(dev), + if (br_fill_ifinfo(skb, port, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq, RTM_NEWLINK, NLM_F_MULTI) < 0) @@ -169,9 +171,9 @@ static int br_rtm_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) if (!dev) return -ENODEV; - if (!br_port_exists(dev)) - return -EINVAL; p = br_port_get(dev); + if (!p) + return -EINVAL; /* if kernel STP is running, don't allow changes */ if (p->br->stp_enabled == BR_KERNEL_STP) |