[IPV4]: Prevent oops when printing martian source

In some cases, we may be generating packets with a source address that qualifies as martian. This can happen when we're in the middle of setting up the network, and netfilter decides to reject a packet with an RST. The IPv4 routing code would try to print a warning and oops, because locally generated packets do not have a valid skb->mac.raw pointer at this point. Signed-off-by: David S. Miller <[email protected]>
mna · Jul 12, 2005 · 0b7f22a · 0b7f22a
1 parent af9debd
commit 0b7f22a
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
@@ -1685,7 +1685,7 @@ static void ip_handle_martian_source(struct net_device *dev,
 		printk(KERN_WARNING "martian source %u.%u.%u.%u from "
 			"%u.%u.%u.%u, on dev %s\n",
 			NIPQUAD(daddr), NIPQUAD(saddr), dev->name);
-		if (dev->hard_header_len) {
+		if (dev->hard_header_len && skb->mac.raw) {
 			int i;
 			unsigned char *p = skb->mac.raw;
 			printk(KERN_WARNING "ll header: ");