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 <dan.carpenter@oracle.com>
Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index e8e524a..002a755 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -275,13 +275,15 @@
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: