ipv6: gre: fix ip6gre_err()
ip6gre_err() miscomputes grehlen (sizeof(ipv6h) is 4 or 8,
not 40 as expected), and should take into account 'offset' parameter.
Also uses pskb_may_pull() to cope with some fragged skbs
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index a84ad5d..424d11a 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -415,8 +415,8 @@
u8 type, u8 code, int offset, __be32 info)
{
const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
- __be16 *p = (__be16 *)(ipv6h + 1);
- int grehlen = sizeof(ipv6h) + 4;
+ __be16 *p = (__be16 *)(skb->data + offset);
+ int grehlen = offset + 4;
struct ip6_tnl *t;
__be16 flags;
@@ -432,8 +432,10 @@
}
/* If only 8 bytes returned, keyed message will be dropped here */
- if (skb_headlen(skb) < grehlen)
+ if (!pskb_may_pull(skb, grehlen))
return;
+ ipv6h = (const struct ipv6hdr *)skb->data;
+ p = (__be16 *)(skb->data + offset);
rcu_read_lock();