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From:   Zhouyang Jia <jiazhouyang09@gmail.com>
Cc:     Zhouyang Jia <jiazhouyang09@gmail.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Vivien Didelot <vivien.didelot@savoirfairelinux.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        "David S. Miller" <davem@davemloft.net>, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH] net: dsa: add error handling for pskb_trim_rcsum
Date:   Mon, 11 Jun 2018 13:26:35 +0800
Message-Id: <1528694795-32000-1-git-send-email-jiazhouyang09@gmail.com>
To:     unlisted-recipients:; (no To-header on input)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

When pskb_trim_rcsum fails, the lack of error-handling code may
cause unexpected results.

This patch adds error-handling code after calling pskb_trim_rcsum.

Signed-off-by: Zhouyang Jia <jiazhouyang09@gmail.com>
---
 net/dsa/tag_trailer.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/dsa/tag_trailer.c b/net/dsa/tag_trailer.c
index 7d20e1f..56197f0 100644
--- a/net/dsa/tag_trailer.c
+++ b/net/dsa/tag_trailer.c
@@ -75,7 +75,8 @@ static struct sk_buff *trailer_rcv(struct sk_buff *skb, struct net_device *dev,
 	if (!skb->dev)
 		return NULL;
 
-	pskb_trim_rcsum(skb, skb->len - 4);
+	if (pskb_trim_rcsum(skb, skb->len - 4))
+		return NULL;
 
 	return skb;
 }
-- 
2.7.4