[PATCH 4.16 04/64] net: dsa: add error handling for pskb_trim_rcsum

[Greg Kroah-Hartman]

4.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Zhouyang Jia <jiazhouyan...@gmail.com>

[ 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 <jiazhouyan...@gmail.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 net/dsa/tag_trailer.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/net/dsa/tag_trailer.c
+++ b/net/dsa/tag_trailer.c
@@ -75,7 +75,8 @@ static struct sk_buff *trailer_rcv(struc
        if (!skb->dev)
                return NULL;
 
-       pskb_trim_rcsum(skb, skb->len - 4);
+       if (pskb_trim_rcsum(skb, skb->len - 4))
+               return NULL;
 
        return skb;
 }