This is a note to let you know that I've just added the patch titled
can: dev: can_put_echo_skb(): don't crash kernel if can_priv::echo_skb is accessed out of bounds
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
can-dev-can_put_echo_skb-don-t-crash-kernel-if-can_p.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 380c98496a4d23437f9ce5a4cdfa72393c96d7ef
Author: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Date: Fri Sep 29 10:23:47 2023 +0200
can: dev: can_put_echo_skb(): don't crash kernel if can_priv::echo_skb is accessed out of bounds
[ Upstream commit 6411959c10fe917288cbb1038886999148560057 ]
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: a6e4bc530403 ("can: make the number of echo skb's configurable")
Link: https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-5-91b5c1fd922c@xxxxxxxxxxxxxx
Reviewed-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/can/dev/skb.c b/drivers/net/can/dev/skb.c
index f6d05b3ef59ab..3ebd4f779b9bd 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c
@@ -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) ||
