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/af_inet6.c b/net/ipv6/af_inet6.c
index 95f4841..03e6ef3 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -816,7 +816,6 @@
const struct inet6_protocol *ops;
int proto;
struct frag_hdr *fptr;
- unsigned int unfrag_ip6hlen;
u8 *prevhdr;
int offset = 0;
@@ -855,11 +854,11 @@
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);
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);
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index df33bb5..2d10b80 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -1315,6 +1315,7 @@
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))
@@ -1351,9 +1352,10 @@
/* 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) +