Commit 6411959c authored by Marc Kleine-Budde's avatar Marc Kleine-Budde
Browse files

can: dev: can_put_echo_skb(): don't crash kernel if can_priv::echo_skb is accessed out of bounds 

If the "struct can_priv::echoo_skb" is accessed out of bounds, this
would cause a kernel crash. Instead, issue a meaningful warning
message and return with an error.

Fixes: a6e4bc53 ("can: make the number of echo skb's configurable")
Link: https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-5-91b5c1fd922c@pengutronix.de


Reviewed-by: default avatarVincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent f0e0c809

drivers/net/can/dev/skb.c

+5 −1
Original line number Diff line number Diff line
@@ -49,7 +49,11 @@ int can_put_echo_skb(struct sk_buff *skb, struct net_device *dev, 
{

	struct can_priv *priv = netdev_priv(dev);



	BUG_ON(idx >= priv->echo_skb_max);

	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);

		return -EINVAL;

	}



	/* check flag whether this packet has to be looped back */

	if (!(dev->flags & IFF_ECHO) ||