From 243cd0318af7e007a83a75f5c2cb6f55d5b91cf2 Mon Sep 17 00:00:00 2001
From: Sepherosa Ziehau <sephe@dragonflybsd.org>
Date: Thu, 16 Aug 2012 10:31:31 +0800
Subject: [PATCH] tcp: Stringent TSO segment length assertion.

---
 sys/netinet/tcp_output.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
index d3d6a0f0ab..a99cbbdeb6 100644
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -771,7 +771,8 @@ send:
 #endif
 
 	if (use_tso) {
-		KASSERT(len > segsz,
+		/* TSO segment length must be multiple of segment size */
+		KASSERT(len >= (2 * segsz) && (len % segsz == 0),
 		    ("invalid TSO len %ld, segsz %u", len, segsz));
 	} else {
 		KASSERT(len <= segsz,
-- 
2.41.0