Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

[platform/kernel/linux-starfive.git] / net / dccp / ipv6.c

diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index 686090b..33f6ccf 100644 (file)
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -74,7 +74,7 @@ static inline __u64 dccp_v6_init_sequence(struct sk_buff *skb)
 static int dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
                        u8 type, u8 code, int offset, __be32 info)
 {
-       const struct ipv6hdr *hdr = (const struct ipv6hdr *)skb->data;
+       const struct ipv6hdr *hdr;
        const struct dccp_hdr *dh;
        struct dccp_sock *dp;
        struct ipv6_pinfo *np;
@@ -83,12 +83,17 @@ static int dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
        __u64 seq;
        struct net *net = dev_net(skb->dev);
 
-       /* Only need dccph_dport & dccph_sport which are the first
-        * 4 bytes in dccp header.
+       /* For the first __dccp_basic_hdr_len() check, we only need dh->dccph_x,
+        * which is in byte 7 of the dccp header.
         * Our caller (icmpv6_notify()) already pulled 8 bytes for us.
+        *
+        * Later on, we want to access the sequence number fields, which are
+        * beyond 8 bytes, so we have to pskb_may_pull() ourselves.
         */
-       BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_sport) > 8);
-       BUILD_BUG_ON(offsetofend(struct dccp_hdr, dccph_dport) > 8);
+       dh = (struct dccp_hdr *)(skb->data + offset);
+       if (!pskb_may_pull(skb, offset + __dccp_basic_hdr_len(dh)))
+               return -EINVAL;
+       hdr = (const struct ipv6hdr *)skb->data;
        dh = (struct dccp_hdr *)(skb->data + offset);
 
        sk = __inet6_lookup_established(net, &dccp_hashinfo,