Subject: [PATCH 04/12] net: dsa: add error handling for pskb_trim_rcsum

From: Zhouyang Jia <[email-masked]>
Date: Mon, 11 Jun 2018 13:26:35 +0800

[ Upstream commit 349b71d6f427ff8211adf50839dbbff3f27c1805 ]

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 <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 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 7d20e1f3de28..56197f0d9608 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;
 }
-- 
2.17.1