From cc5706056baa3002b844ff240a1cc2199a978795 Mon Sep 17 00:00:00 2001 From: Joe Stringer Date: Mon, 14 Sep 2015 11:14:50 -0700 Subject: [PATCH] openvswitch: Fix IPv6 exthdr handling with ct helpers. Static code analysis reveals the following bug: net/openvswitch/conntrack.c:281 ovs_ct_helper() warn: unsigned 'protoff' is never less than zero. This signedness bug breaks error handling for IPv6 extension headers when using conntrack helpers. Fix the error by using a local signed variable. Fixes: cae3a2627520: "openvswitch: Allow attaching helpers to ct action" Reported-by: Dan Carpenter Signed-off-by: Joe Stringer Acked-by: Pravin B Shelar Signed-off-by: David S. Miller --- net/openvswitch/conntrack.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c index e8e524ad8a01..002a755fa07e 100644 --- a/net/openvswitch/conntrack.c +++ b/net/openvswitch/conntrack.c @@ -275,13 +275,15 @@ static int ovs_ct_helper(struct sk_buff *skb, u16 proto) case NFPROTO_IPV6: { u8 nexthdr = ipv6_hdr(skb)->nexthdr; __be16 frag_off; + int ofs; - protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), - &nexthdr, &frag_off); - if (protoff < 0 || (frag_off & htons(~0x7)) != 0) { + ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr, + &frag_off); + if (ofs < 0 || (frag_off & htons(~0x7)) != 0) { pr_debug("proto header not found\n"); return NF_ACCEPT; } + protoff = ofs; break; } default: -- 2.30.2