diff options
Diffstat (limited to 'net/dccp/ipv4.c')
| -rw-r--r-- | net/dccp/ipv4.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c index 1591b061105a..8f56e8723c73 100644 --- a/net/dccp/ipv4.c +++ b/net/dccp/ipv4.c @@ -254,12 +254,17 @@ static int dccp_v4_err(struct sk_buff *skb, u32 info) int err; 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 (icmp_socket_deliver()) 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; + iph = (struct iphdr *)skb->data; dh = (struct dccp_hdr *)(skb->data + offset); sk = __inet_lookup_established(net, &dccp_hashinfo, |