# \[PATCH net 10/14\] can: dev: can\_put\_echo\_skb(): free skb on invalid echo index - From: Marc Kleine-Budde \ - Date: 2026-08-26 12:10:48 - List: netdev - Page: https://ratatoskr.run/netdev/2026/08/17464327 - Thread: https://ratatoskr.run/netdev/2026/08/17464352/t.md ```text From: Cunhao Lu can_put_echo_skb() consumes the skb on all paths except when the echo index is out of bounds. This leaves ownership with the caller on -EINVAL, unlike the other error paths, and can leak the skb if the caller expects consistent semantics. Free the skb before returning -EINVAL so that all return paths consume it. Fixes: 6411959c10fe ("can: dev: can_put_echo_skb(): don't crash kernel if can_priv::echo_skb is accessed out of bounds") Cc: Reviewed-by: Vincent Mailhol Signed-off-by: Cunhao Lu Link: https://patch.msgid.link/tencent_683AA16E643DE00211CD2FB62991264DC605@qq.com Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev/skb.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c index c7be21ed70dd..faafb1033d42 100644 --- a/drivers/net/can/dev/skb.c +++ b/drivers/net/can/dev/skb.c @@ -55,6 +55,7 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, if (idx >= priv->echo_skb_max) { netdev_err(dev, "%s: BUG! Trying to access can_priv::echo_skb out of bounds (%u/max %u)\n", __func__, idx, priv->echo_skb_max); + dev_kfree_skb_any(skb); return -EINVAL; } -- 2.53.0 ```