[PATCH 6.0 113/157] net: dsa: sja1105: Check return value

Greg Kroah-Hartman
2022-12-12T13:44:07Z

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

[ Upstream commit 8948876335b1752176afdff8e704099a3ea0f6e6 ]

Return NULL if we got unexpected value from skb_trim_rcsum() in
sja1110_rcv_inband_control_extension()

Fixes: 4913b8ebf8a9 ("net: dsa: add support for the SJA1110 native tagging protocol")
Signed-off-by: Artem Chernyshev <artem.chernyshev@red-soft.ru>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20221201140032.26746-3-artem.chernyshev@red-soft.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/dsa/tag_sja1105.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/dsa/tag_sja1105.c b/net/dsa/tag_sja1105.c
index 83e4136516b0..1a85125bda6d 100644
--- a/net/dsa/tag_sja1105.c
+++ b/net/dsa/tag_sja1105.c
@@ -665,7 +665,8 @@ static struct sk_buff *sja1110_rcv_inband_control_extension(struct sk_buff *skb,
* padding and trailer we need to account for the fact that
* skb->data points to skb_mac_header(skb) + ETH_HLEN.
*/
- pskb_trim_rcsum(skb, start_of_padding - ETH_HLEN);
+ if (pskb_trim_rcsum(skb, start_of_padding - ETH_HLEN))
+ return NULL;
/* Trap-to-host frame, no timestamp trailer */
} else {
*source_port = SJA1110_RX_HEADER_SRC_PORT(rx_header);
--
2.35.1