1 files changed, 17 insertions, 7 deletions

diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 757c9171e7c2..ab996f9c0fe0 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -352,13 +352,24 @@ static int raw_send_hdrinc(struct sock *sk, void *from, size_t length,
 	skb->ip_summed = CHECKSUM_NONE;
 
 	skb->transport_header = skb->network_header;
-	err = memcpy_fromiovecend((void *)iph, from, 0, length);
-	if (err)
-		goto error_fault;
+	err = -EFAULT;
+	if (memcpy_fromiovecend((void *)iph, from, 0, length))
+		goto error_free;
 
-	/* We don't modify invalid header */
 	iphlen = iph->ihl * 4;
-	if (iphlen >= sizeof(*iph) && iphlen <= length) {
+
+	/*
+	 * We don't want to modify the ip header, but we do need to
+	 * be sure that it won't cause problems later along the network
+	 * stack.  Specifically we want to make sure that iph->ihl is a
+	 * sane value.  If ihl points beyond the length of the buffer passed
+	 * in, reject the frame as invalid
+	 */
+	err = -EINVAL;
+	if (iphlen > length)
+		goto error_free;
+
+	if (iphlen >= sizeof(*iph)) {
 		if (!iph->saddr)
 			iph->saddr = rt->rt_src;
 		iph->check   = 0;
@@ -381,8 +392,7 @@ static int raw_send_hdrinc(struct sock *sk, void *from, size_t length,
 out:
 	return 0;
 
-error_fault:
-	err = -EFAULT;
+error_free:
 	kfree_skb(skb);
 error:
 	IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS);