From 71f6f6dfdf7c7a67462386d9ea05c1095a89c555 Mon Sep 17 00:00:00 2001 From: Jesper Nilsson Date: Fri, 27 Mar 2009 00:17:45 -0700 Subject: [PATCH] ipv6: Plug sk_buff leak in ipv6_rcv (net/ipv6/ip6_input.c) Commit 778d80be52699596bf70e0eb0761cf5e1e46088d (ipv6: Add disable_ipv6 sysctl to disable IPv6 operaion on specific interface) seems to have introduced a leak of sk_buff's for ipv6 traffic, at least in some configurations where idev is NULL, or when ipv6 is disabled via sysctl. The problem is that if the first condition of the if-statement returns non-NULL, it returns an skb with only one reference, and when the other conditions apply, execution jumps to the "out" label, which does not call kfree_skb for it. To plug this leak, change to use the "drop" label instead. (this relies on it being ok to call kfree_skb on NULL) This also allows us to avoid calling rcu_read_unlock here, and removes the only user of the "out" label. Signed-off-by: Jesper Nilsson Signed-off-by: David S. Miller --- net/ipv6/ip6_input.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c index f171e8dbac91..8f04bd9da274 100644 --- a/net/ipv6/ip6_input.c +++ b/net/ipv6/ip6_input.c @@ -75,8 +75,7 @@ int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL || !idev || unlikely(idev->cnf.disable_ipv6)) { IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS); - rcu_read_unlock(); - goto out; + goto drop; } memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm)); @@ -147,7 +146,6 @@ err: drop: rcu_read_unlock(); kfree_skb(skb); -out: return 0; }