From d0e16e0d1e3a8e7bfc6cefa0a715ccfda90d0dbd Mon Sep 17 00:00:00 2001
From: Gleb Smirnoff <glebius@FreeBSD.org>
Date: Mon, 18 Apr 2011 18:22:10 +0000
Subject: [PATCH] Pullup up to TCP header length before matching against
 'tcpopts'.

PR:		kern/156180
Reviewed by:	luigi
---
 sys/netinet/ipfw/ip_fw2.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/sys/netinet/ipfw/ip_fw2.c b/sys/netinet/ipfw/ip_fw2.c
index c8deb895b9a..119b9a1a77c 100644
--- a/sys/netinet/ipfw/ip_fw2.c
+++ b/sys/netinet/ipfw/ip_fw2.c
@@ -913,9 +913,10 @@ ipfw_chk(struct ip_fw_args *args)
  * pointer might become stale after other pullups (but we never use it
  * this way).
  */
-#define PULLUP_TO(_len, p, T)					\
+#define PULLUP_TO(_len, p, T)	PULLUP_LEN(_len, p, sizeof(T))
+#define PULLUP_LEN(_len, p, T)					\
 do {								\
-	int x = (_len) + sizeof(T);				\
+	int x = (_len) + T;					\
 	if ((m)->m_len < x) {					\
 		args->m = m = m_pullup(m, x);			\
 		if (m == NULL)					\
@@ -1600,6 +1601,7 @@ do {								\
 				break;
 
 			case O_TCPOPTS:
+				PULLUP_LEN(hlen, ulp, (TCP(ulp)->th_off << 2));
 				match = (proto == IPPROTO_TCP && offset == 0 &&
 				    tcpopts_match(TCP(ulp), cmd));
 				break;
@@ -2233,6 +2235,7 @@ do {								\
 			}
 
 		}	/* end of inner loop, scan opcodes */
+#undef PULLUP_LEN
 
 		if (done)
 			break;