[PATCH AUTOSEL 5.12 035/116] can: dev: can_free_echo_skb(): don't crash the kernel if can_priv::echo_skb is accessed out of bounds
From: Sasha Levin <sashal@kernel.org>
Date: 2021-05-05 16:34:00
Also in:
linux-can, lkml, netdev
Subsystem:
can network drivers, the rest · Maintainers:
Marc Kleine-Budde, Vincent Mailhol, Linus Torvalds
From: Marc Kleine-Budde <mkl@pengutronix.de>
[ Upstream commit 4168d079aa41498639b2c64b4583375bcdf360d9 ]
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 (local)
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 6a64fe410987..c3508109263e 100644
--- a/drivers/net/can/dev/skb.c
+++ b/drivers/net/can/dev/skb.c@@ -151,7 +151,11 @@ 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]);
--
2.30.2