ipv6: Check ip6_find_1stfragopt() return value properly.
commit 7dd7eb9513bd02184d45f000ab69d78cb1fa1531 upstream.
Do not use unsigned variables to see if it returns a negative
error or not.
Change-Id: Id592a2b94f9ada817145118b20e02832c833d84f
Fixes: 2423496af35d ("ipv6: Prevent overrun when parsing v6 header options")
Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 078e7cb..a3489f2 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -639,11 +639,10 @@
u8 *prevhdr, nexthdr = 0;
struct net *net = dev_net(skb_dst(skb)->dev);
- hlen = ip6_find_1stfragopt(skb, &prevhdr);
- if (hlen < 0) {
- err = hlen;
+ err = ip6_find_1stfragopt(skb, &prevhdr);
+ if (err < 0)
goto fail;
- }
+ hlen = err;
nexthdr = *prevhdr;
mtu = ip6_skb_dst_mtu(skb);