net: dsa: add error handling for pskb_trim_rcsum

[ 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 <jiazhouyang09@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/dsa/tag_trailer.c b/net/dsa/tag_trailer.c
index fcc9aa72877d685986b1ec52df13bc5a650fbcad..374d586b4a2c2e0592357c3566448c67278b9a9e 100644 (file)
--- a/net/dsa/tag_trailer.c
+++ b/net/dsa/tag_trailer.c
@@ -79,7 +79,8 @@ static struct sk_buff *trailer_rcv(struct sk_buff *skb, struct net_device *dev,
        if (unlikely(ds->cpu_port_mask & BIT(source_port)))
                return NULL;
 
-       pskb_trim_rcsum(skb, skb->len - 4);
+       if (pskb_trim_rcsum(skb, skb->len - 4))
+               return NULL;
 
        skb->dev = ds->ports[source_port].netdev;