From f76d54a8882ed61d4686707fff58a84a1664860c Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 17 May 2017 22:54:11 -0400 Subject: [PATCH] ipv6: Check ip6_find_1stfragopt() return value properly. [ Upstream commit 7dd7eb9513bd02184d45f000ab69d78cb1fa1531 ] 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/ip6_offload.c | 9 ++++----- net/ipv6/ip6_output.c | 7 +++---- net/ipv6/udp_offload.c | 8 +++++--- 3 files changed, 12 insertions(+), 12 deletions(-) diff --git a/net/ipv6/ip6_offload.c b/net/ipv6/ip6_offload.c index 9a2247cfafbf..568bc0a52ca1 100644 --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -62,7 +62,6 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb, const struct net_offload *ops; int proto; struct frag_hdr *fptr; - unsigned int unfrag_ip6hlen; u8 *prevhdr; int offset = 0; bool encap, udpfrag; @@ -121,10 +120,10 @@ static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb, skb->network_header = (u8 *)ipv6h - skb->head; if (udpfrag) { - unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr); - if (unfrag_ip6hlen < 0) - return ERR_PTR(unfrag_ip6hlen); - fptr = (struct frag_hdr *)((u8 *)ipv6h + unfrag_ip6hlen); + int err = ip6_find_1stfragopt(skb, &prevhdr); + if (err < 0) + return ERR_PTR(err); + fptr = (struct frag_hdr *)((u8 *)ipv6h + err); fptr->frag_off = htons(offset); if (skb->next) fptr->frag_off |= htons(IP6_MF); diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 7a3a29cc033b..077e29bba699 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -571,11 +571,10 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, int ptr, offset = 0, err = 0; u8 *prevhdr, nexthdr = 0; - 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); diff --git a/net/ipv6/udp_offload.c b/net/ipv6/udp_offload.c index 04ed91da6cc9..01582966ffa0 100644 --- a/net/ipv6/udp_offload.c +++ b/net/ipv6/udp_offload.c @@ -29,6 +29,7 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, u8 frag_hdr_sz = sizeof(struct frag_hdr); __wsum csum; int tnl_hlen; + int err; mss = skb_shinfo(skb)->gso_size; if (unlikely(skb->len <= mss)) @@ -97,9 +98,10 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, /* 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)) + -- 2.20.1