From 6411959c10fe917288cbb1038886999148560057 Mon Sep 17 00:00:00 2001
From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: Fri, 29 Sep 2023 10:23:47 +0200
Subject: [PATCH] can: dev: can_put_echo_skb(): don't crash kernel if can_priv::echo_skb is accessed out of bounds
Git-commit: 6411959c10fe917288cbb1038886999148560057
Patch-mainline: v6.7-rc1
References: git-fixes
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@pengutronix.de
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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 f6d05b3ef59a..3ebd4f779b9b 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) ||
--
2.35.3