From c52a3f89f882b84fc422000655c023fe73e701cf Mon Sep 17 00:00:00 2001
From: Thomas Graf <tgraf@suug.ch>
Date: Sat, 18 Jun 2005 22:51:26 -0700
Subject: [PATCH] [NETLINK]: Fix RTA_NEST_CANCEL().

Only skb_trim() if 'start' is non-NULL.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 include/linux/rtnetlink.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index 5a5cda1602..6fff8c4c99 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -924,7 +924,8 @@ extern void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const voi
 	(skb)->len; })
 
 #define RTA_NEST_CANCEL(skb, start) \
-({	skb_trim(skb, (unsigned char *) (start) - (skb)->data); \
+({	if (start) \
+		skb_trim(skb, (unsigned char *) (start) - (skb)->data); \
 	-1; })
 
 #define RTA_GET_U32(rta) \
-- 
2.39.5