[PATCH 6.0 112/157] net: dsa: hellcreek: Check return value

Greg Kroah-Hartman
2022-12-12T13:44:06Z

From: Artem Chernyshev <artem.chernyshev@red-soft.ru>

[ Upstream commit d4edb50688652eb10be270bc515da63815de428f ]

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@red-soft.ru>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Link: https://lore.kernel.org/r/20221201140032.26746-2-artem.chernyshev@red-soft.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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);

--
2.35.1