3.2.89-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "David S. Miller" <davem@xxxxxxxxxxxxx> commit 7dd7eb9513bd02184d45f000ab69d78cb1fa1531 upstream. Do not use unsigned variables to see if it returns a negative error or not. Fixes: 2423496af35d ("ipv6: Prevent overrun when parsing v6 header options") Reported-by: Julia Lawall <julia.lawall@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> [bwh: Backported to 3.2: adjust filenames, context] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> --- --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -785,7 +785,6 @@ static struct sk_buff *ipv6_gso_segment( const struct inet6_protocol *ops; int proto; struct frag_hdr *fptr; - unsigned int unfrag_ip6hlen; u8 *prevhdr; int offset = 0; @@ -824,11 +823,11 @@ static struct sk_buff *ipv6_gso_segment( ipv6h->payload_len = htons(skb->len - skb->mac_len - sizeof(*ipv6h)); if (proto == IPPROTO_UDP) { - unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr); - if (unfrag_ip6hlen < 0) - return ERR_PTR(unfrag_ip6hlen); + int err = ip6_find_1stfragopt(skb, &prevhdr); + if (err < 0) + return ERR_PTR(err); fptr = (struct frag_hdr *)(skb_network_header(skb) + - unfrag_ip6hlen); + err); fptr->frag_off = htons(offset); if (skb->next != NULL) fptr->frag_off |= htons(IP6_MF); --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -631,11 +631,10 @@ int ip6_fragment(struct sk_buff *skb, in 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); --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -1316,6 +1316,7 @@ static struct sk_buff *udp6_ufo_fragment u8 frag_hdr_sz = sizeof(struct frag_hdr); int offset; __wsum csum; + int err; mss = skb_shinfo(skb)->gso_size; if (unlikely(skb->len <= mss)) @@ -1352,9 +1353,10 @@ static struct sk_buff *udp6_ufo_fragment /* Find the unfragmentable header and shift it left by frag_hdr_sz * bytes to insert fragment header. */ - unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr); - if (unfrag_ip6hlen < 0) - return ERR_PTR(unfrag_ip6hlen); + err = ip6_find_1stfragopt(skb, &prevhdr); + if (err < 0) + return ERR_PTR(err); + unfrag_ip6hlen = err; nexthdr = *prevhdr; *prevhdr = NEXTHDR_FRAGMENT; unfrag_len = skb_network_header(skb) - skb_mac_header(skb) +