From 55b8050353c4a212c94d7156e2bd5885225b869b Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 19 Oct 2009 06:41:58 +0000 Subject: net: Fix IP_MULTICAST_IF ipv4/ipv6 setsockopt(IP_MULTICAST_IF) have dubious __dev_get_by_index() calls. This function should be called only with RTNL or dev_base_lock held, or reader could see a corrupt hash chain and eventually enter an endless loop. Fix is to call dev_get_by_index()/dev_put(). If this happens to be performance critical, we could define a new dev_exist_by_index() function to avoid touching dev refcount. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv6/ipv6_sockglue.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'net/ipv6') diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c index 14f54eb5a7f..4f7aaf6996a 100644 --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -496,13 +496,17 @@ done: goto e_inval; if (val) { + struct net_device *dev; + if (sk->sk_bound_dev_if && sk->sk_bound_dev_if != val) goto e_inval; - if (__dev_get_by_index(net, val) == NULL) { + dev = dev_get_by_index(net, val); + if (!dev) { retv = -ENODEV; break; } + dev_put(dev); } np->mcast_oif = val; retv = 0; -- cgit v1.2.3