From f1791425cf0bcda43ab9a9a37df1ad3ccb1f6654 Mon Sep 17 00:00:00 2001
From: Antonio Quartulli <antonio@meshcoding.com>
Date: Thu, 30 Jan 2014 00:12:24 +0100
Subject: [PATCH] batman-adv: properly check pskb_may_pull return value

pskb_may_pull() returns 1 on success and 0 in case of failure,
therefore checking for the return value being negative does
not make sense at all.

This way if the function fails we will probably read beyond the current
skb data buffer. Fix this by doing the proper check.

Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
---
 net/batman-adv/routing.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c
index 1ed9f7c9ecea..c26f07368849 100644
--- a/net/batman-adv/routing.c
+++ b/net/batman-adv/routing.c
@@ -688,7 +688,7 @@ static int batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
 	int is_old_ttvn;
 
 	/* check if there is enough data before accessing it */
-	if (pskb_may_pull(skb, hdr_len + ETH_HLEN) < 0)
+	if (!pskb_may_pull(skb, hdr_len + ETH_HLEN))
 		return 0;
 
 	/* create a copy of the skb (in case of for re-routing) to modify it. */
-- 
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