The min length of dccp packet is 12, and if we want check the sequence
number, the length of dccp packet must not less than
__dccp_basic_hdr_len(dh). If the length of dccp packet is less than this
value, check for sequence number will get unpredictable result.
This patch fix the problem.
Signed-off-by: Wei Yongjun <yjwei@xxxxxxxxxxxxxx>
diff -Nurp a/net/dccp/ipv4.c b/net/dccp/ipv4.c
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -196,8 +196,8 @@ static inline void dccp_do_pmtu_discovery(struct sock *sk,
static void dccp_v4_err(struct sk_buff *skb, u32 info)
{
const struct iphdr *iph = (struct iphdr *)skb->data;
- const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data +
- (iph->ihl << 2));
+ const int ihlen = iph->ihl * 4;
+ const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + ihlen);
struct dccp_sock *dp;
struct inet_sock *inet;
const int type = icmp_hdr(skb)->type;
@@ -206,7 +206,8 @@ static void dccp_v4_err(struct sk_buff *skb, u32 info)
__u64 seq;
int err;
- if (skb->len < (iph->ihl << 2) + 8) {
+ if (skb->len < ihlen + 12 ||
+ skb->len < ihlen + __dccp_basic_hdr_len(dh)) {
ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
return;
}
--
To unsubscribe from this list: send the line "unsubscribe dccp" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
