From: Artem Chernyshev <artem.chernyshev@red-soft.ru>
Date: Thu, 1 Dec 2022 14:00:30 +0000 (+0300)
Subject: net: dsa: ksz: Check return value
X-Git-Tag: v5.15.92~1543
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a4c342e645d6bc7d947d682fcfd4fc245ecf99e5;p=platform%2Fkernel%2Flinux-rpi.git

net: dsa: ksz: Check return value

[ Upstream commit 3d8fdcbf1f42e2bb9ae8b8c0b6f202278c788a22 ]

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: bafe9ba7d908 ("net: dsa: ksz: Factor out common tag code")
Signed-off-by: Artem Chernyshev <artem.chernyshev@red-soft.ru>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20221201140032.26746-1-artem.chernyshev@red-soft.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
index fa1d60d..6795dd0 100644
--- a/net/dsa/tag_ksz.c
+++ b/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;
 
 	dsa_default_offload_fwd_mark(skb);