Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751767AbdFAP6l (ORCPT ); Thu, 1 Jun 2017 11:58:41 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33936 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752292AbdFAPpQ (ORCPT ); Thu, 1 Jun 2017 11:45:16 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "David S. Miller" , "Julia Lawall" Date: Thu, 01 Jun 2017 16:43:16 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 209/212] ipv6: Check ip6_find_1stfragopt() return value properly. In-Reply-To: X-SA-Exim-Connect-IP: 82.70.136.246 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2750 Lines: 88 3.16.44-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: "David S. Miller" 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 Signed-off-by: David S. Miller [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- 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(-) --- a/net/ipv6/ip6_offload.c +++ b/net/ipv6/ip6_offload.c @@ -86,7 +86,6 @@ static struct sk_buff *ipv6_gso_segment( const struct net_offload *ops; int proto; struct frag_hdr *fptr; - unsigned int unfrag_ip6hlen; u8 *prevhdr; int offset = 0; bool encap, udpfrag; @@ -144,10 +143,10 @@ static struct sk_buff *ipv6_gso_segment( 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 != NULL) fptr->frag_off |= htons(IP6_MF); --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -566,11 +566,10 @@ 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_offload.c +++ b/net/ipv6/udp_offload.c @@ -51,6 +51,7 @@ static struct sk_buff *udp6_ufo_fragment int offset; __wsum csum; int tnl_hlen; + int err; mss = skb_shinfo(skb)->gso_size; if (unlikely(skb->len <= mss)) @@ -101,9 +102,10 @@ 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)) +