netfilter: bridge: don't leak skb in error paths

br_nf_dev_queue_xmit must free skb in its error path.
NF_DROP is misleading -- its an okfn, not a netfilter hook.

Fixes: 462fb2af9788a ("bridge : Sanitize skb before it enters the IP stack")
Fixes: efb6de9b4ba00 ("netfilter: bridge: forward IPv6 fragmented packets")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 8 insertions, 4 deletions

diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c
index 8a394bd3af83..c8b9bcfe997e 100644
--- a/net/bridge/br_netfilter_hooks.c
+++ b/net/bridge/br_netfilter_hooks.c
@@ -744,7 +744,7 @@ static int br_nf_dev_queue_xmit(struct sock *sk, struct sk_buff *skb)
                 struct brnf_frag_data *data;
 
                 if (br_validate_ipv4(skb))
-                        return NF_DROP;
+                        goto drop;
 
                 IPCB(skb)->frag_max_size = nf_bridge->frag_max_size;
 
@@ -769,7 +769,7 @@ static int br_nf_dev_queue_xmit(struct sock *sk, struct sk_buff *skb)
                 struct brnf_frag_data *data;
 
                 if (br_validate_ipv6(skb))
-                        return NF_DROP;
+                        goto drop;
 
                 IP6CB(skb)->frag_max_size = nf_bridge->frag_max_size;
 
@@ -784,12 +784,16 @@ static int br_nf_dev_queue_xmit(struct sock *sk, struct sk_buff *skb)
 
                 if (v6ops)
                         return v6ops->fragment(sk, skb, br_nf_push_frag_xmit);
-                else
-                        return -EMSGSIZE;
+
+                kfree_skb(skb);
+                return -EMSGSIZE;
         }
 #endif
         nf_bridge_info_free(skb);
         return br_dev_queue_push_xmit(sk, skb);
+ drop:
+        kfree_skb(skb);
+        return 0;
 }
 
 /* PF_BRIDGE/POST_ROUTING ********************************************/