[PATCH]: fixed kernel panic when trying to find tcp option

[Yasuyuki Kozakai]

Hi,

This patch fixed panic on 2.6.9-rc2 when trying to find tcp option
in the packet which has no option.

If not fixed yet, please apply this patch.

Regards,

-----------------------------------------------------------------
Yasuyuki KOZAKAI @ USAGI Project <yasuyuki.kozakai at toshiba.co.jp>

-------------- next part --------------
--- linux-2.6.9-rc2/net/ipv4/netfilter/ip_tables.c	2004-09-15 14:04:16.000000000 +0900
+++ linux-2.6.9-rc2-nolinearize/net/ipv4/netfilter/ip_tables.c	2004-09-15 20:01:42.970226904 +0900
@@ -1464,8 +1464,9 @@ tcp_find_option(u_int8_t option,
 	unsigned int i;
 
 	duprintf("tcp_match: finding option\n");
+	if (!optlen)
+		return invert;
 	/* If we don't have the whole header, drop packet. */
-	BUG_ON(!optlen);
 	op = skb_header_pointer(skb,
 				skb->nh.iph->ihl*4 + sizeof(struct tcphdr),
 				optlen, _opt);