From 4168d079aa41498639b2c64b4583375bcdf360d9 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Fri, 19 Mar 2021 15:08:13 +0100 Subject: [PATCH] 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: | e7a6994d043a ("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 --- drivers/net/can/dev/skb.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c index 22b0472a5fad1..2256391ddbb3e 100644 --- a/drivers/net/can/dev/skb.c +++ b/drivers/net/can/dev/skb.c @@ -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]); -- 2.39.5