[IPV6]: Ensure to have hop-by-hop options in our header of &sk_buff.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 2a1e7e4..d88cab7 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -489,6 +489,18 @@
{
struct inet6_skb_parm *opt = IP6CB(skb);
+ /*
+ * skb->nh.raw is equal to skb->data, and
+ * skb->h.raw - skb->nh.raw is always equal to
+ * sizeof(struct ipv6hdr) by definition of
+ * hop-by-hop options.
+ */
+ if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
+ !pskb_may_pull(skb, sizeof(struct ipv6hdr) + ((skb->h.raw[1] + 1) << 3))) {
+ kfree_skb(skb);
+ return -1;
+ }
+
opt->hop = sizeof(struct ipv6hdr);
if (ip6_parse_tlv(tlvprochopopt_lst, skb)) {
skb->h.raw += (skb->h.raw[1]+1)<<3;