From e7a6994d043a1e31d5b17706a22ce33d2a3e4cdc Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Wed, 31 Oct 2018 14:05:26 +0100 Subject: [PATCH] can: dev: __can_get_echo_skb(): Don't crash the kernel if can_priv::echo_skb is accessed out of bounds If the "struct can_priv::echo_skb" is accessed out of bounds would lead to a kernel crash. Better print a sensible warning message instead and try to recover. Cc: linux-stable Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c index 46cc5fec4043d9..c05e4d50d43d74 100644 --- a/drivers/net/can/dev.c +++ b/drivers/net/can/dev.c @@ -481,7 +481,11 @@ struct sk_buff *__can_get_echo_skb(struct net_device *dev, unsigned int idx, u8 { 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 NULL; + } if (priv->echo_skb[idx]) { /* Using "struct canfd_frame::len" for the frame