[PATCH 6.0 078/124] can: can327: can327_feed_frame_to_netdev(): fix potential skb leak when netdev is down

Greg Kroah-Hartman
2022-12-05T19:26:12Z

From: Ziyang Xuan <william.xuanziyang@huawei.com>

commit 8fa452cfafed521aaf5a18c71003fe24b1ee6141 upstream.

In can327_feed_frame_to_netdev(), it did not free the skb when netdev
is down, and all callers of can327_feed_frame_to_netdev() did not free
allocated skb too. That would trigger skb leak.

Fix it by adding kfree_skb() in can327_feed_frame_to_netdev() when netdev
is down. Not tested, just compiled.

Fixes: 43da2f07622f ("can: can327: CAN/ldisc driver for ELM327 based OBD-II adapters")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Link: https://lore.kernel.org/all/20221110061437.411525-1-william.xuanziyang@huawei.com
Reviewed-by: Max Staudt <max@enpas.org>
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/can/can327.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/can/can327.c b/drivers/net/can/can327.c
index 094197780776..ed3d0b8989a0 100644
--- a/drivers/net/can/can327.c
+++ b/drivers/net/can/can327.c
@@ -263,8 +263,10 @@ static void can327_feed_frame_to_netdev(struct can327 *elm, struct sk_buff *skb)
{
lockdep_assert_held(&elm->lock);

- if (!netif_running(elm->dev))
+ if (!netif_running(elm->dev)) {
+ kfree_skb(skb);
return;
+ }

/* Queue for NAPI pickup.
* rx-offload will update stats and LEDs for us.
--
2.38.1