[PATCH v3 2/3] net: dsa: hellcreek: Check return value

[Artem Chernyshev]

Return NULL if we got unexpected value from skb_trim_rcsum() 
in hellcreek_rcv()

Fixes: 01ef09caad66 ("net: dsa: Add tag handling for Hirschmann Hellcreek switches")
Signed-off-by: Artem Chernyshev <artem.chernyshev@xxxxxxxxxxx>
---
V1->V2 Fixes for tag_hellcreek.c and tag_sja1105.c
V2->V3 Split patch in 3 separate parts

 net/dsa/tag_hellcreek.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/dsa/tag_hellcreek.c b/net/dsa/tag_hellcreek.c
index 846588c0070a..53a206d11685 100644
--- a/net/dsa/tag_hellcreek.c
+++ b/net/dsa/tag_hellcreek.c
@@ -49,7 +49,8 @@ static struct sk_buff *hellcreek_rcv(struct sk_buff *skb,
 		return NULL;
 	}
 
-	pskb_trim_rcsum(skb, skb->len - HELLCREEK_TAG_LEN);
+	if (pskb_trim_rcsum(skb, skb->len - HELLCREEK_TAG_LEN))
+		return NULL;
 
 	dsa_default_offload_fwd_mark(skb);
 
-- 
2.30.3