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From:   Artem Chernyshev <artem.chernyshev@red-soft.ru>
To:     artem.chernyshev@red-soft.ru, Vladimir Oltean <olteanv@gmail.com>,
        Woojung Huh <woojung.huh@microchip.com>
Cc:     Florian Fainelli <f.fainelli@gmail.com>,
        "David S . Miller" <davem@davemloft.net>,
        UNGLinuxDriver@microchip.com, netdev@vger.kernel.org,
        linux-kernel@vger.kernel.org, lvc-project@linuxtesting.org
Subject: [PATCH v3 1/3] net: dsa: ksz: Check return value
Date:   Thu,  1 Dec 2022 17:00:30 +0300
Message-Id: <20221201140032.26746-1-artem.chernyshev@red-soft.ru>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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>
---
V1->V2 Fixes for tag_hellcreek.c and tag_sja1105.c
V2->V3 Split patch in 3 separate parts

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

diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
index 38fa19c1e2d5..429250298ac4 100644
--- a/net/dsa/tag_ksz.c
+++ b/net/dsa/tag_ksz.c
@@ -21,7 +21,8 @@ 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);
 
-- 
2.30.3