Commit 71f6f6dfdf7c7a67462386d9ea05c1095a89c555

Authored by Jesper Nilsson
Committed by David S. Miller
1 parent a170285772

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 <jesper.nilsson@axis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Showing 1 changed file with 1 additions and 3 deletions Side-by-side Diff

net/ipv6/ip6_input.c
... ... @@ -75,8 +75,7 @@
75 75 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
76 76 !idev || unlikely(idev->cnf.disable_ipv6)) {
77 77 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
78   - rcu_read_unlock();
79   - goto out;
  78 + goto drop;
80 79 }
81 80  
82 81 memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
... ... @@ -147,7 +146,6 @@
147 146 drop:
148 147 rcu_read_unlock();
149 148 kfree_skb(skb);
150   -out:
151 149 return 0;
152 150 }
153 151