net: dsa: ksz: Check return value

stable inclusion
from stable-v5.10.159
commit bccda3ad0748958473eb730e29c0487007a98832
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7NTXH

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=bccda3ad0748958473eb730e29c0487007a98832

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

[ Upstream commit 3d8fdcbf ]

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

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: bafe9ba7 ("net: dsa: ksz: Factor out common tag code")
Signed-off-by: NArtem Chernyshev <artem.chernyshev@red-soft.ru>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Reviewed-by: NFlorian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20221201140032.26746-1-artem.chernyshev@red-soft.ruSigned-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: Nsanglipeng <sanglipeng1@jd.com>

net/dsa/tag_ksz.c

@@ -22,7 +22,8 @@ static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
 	if (!skb->dev)
 		return NULL;
 
-	pskb_trim_rcsum(skb, skb->len - len);
+	if (pskb_trim_rcsum(skb, skb->len - len))
+		return NULL;
 
 	skb->offload_fwd_mark = true;