Commit 4168d079 authored Mar 19, 2021 by Marc Kleine-Budde

can: dev: can_free_echo_skb(): don't crash the kernel if can_priv::echo_skb is...

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

A out of bounds access to "struct can_priv::echo_skb" leads to a
kernel crash. Better print a sensible warning message instead and try
to recover.

This patch is similar to:

| e7a6994d ("can: dev: __can_get_echo_skb(): Don't crash the kernel
|               if can_priv::echo_skb is accessed out of bounds")

Link: https://lore.kernel.org/r/20210319142700.305648-2-mkl@pengutronix.de


Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

parent 7119d786

drivers/net/can/dev/skb.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -157,7 +157,11 @@ void can_free_echo_skb(struct net_device *dev, unsigned int idx)
		{
		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;
		}

		if (priv->echo_skb[idx]) {
		dev_kfree_skb_any(priv->echo_skb[idx]);