diff mbox series

[15/20] can: dev: __can_get_echo_skb(): Don't crash the kernel if can_priv::echo_skb is accessed out of bounds

Message ID 20181112115728.18331-16-mkl@pengutronix.de
State Accepted, archived
Delegated to: David Miller
Headers show
Series pull-request: can 2018-11-09 | expand

Commit Message

Marc Kleine-Budde Nov. 12, 2018, 11:57 a.m. UTC 
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 <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/dev.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c
index 46cc5fec4043..c05e4d50d43d 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