Merge patch series "can: populate ndo_change_mtu() to prevent buffer overflow"

Vincent Mailhol <[email protected]> says:

Four drivers, namely etas_es58x, hi311x, sun4i_can and mcba_usb forgot
to populate their net_device_ops->ndo_change_mtu(). Because of that,
the user is free to configure any MTU on these interfaces.

This can be abused by an attacker who could craft some skbs and send
them through PF_PACKET to perform a buffer overflow of up to 247 bytes
in each of these drivers.

This series contains four patches, one for each of the drivers, to add
the missing ndo_change_mtu() callback. The descriptions contain
detailed explanations of how the buffer overflow could be triggered.

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Marc Kleine-Budde <[email protected]>

Author: marckleinebudde

drivers/net/can/spi/hi311x.c

@@ -799,6 +799,7 @@ static const struct net_device_ops hi3110_netdev_ops = {
 	.ndo_open = hi3110_open,
 	.ndo_stop = hi3110_stop,
 	.ndo_start_xmit = hi3110_hard_start_xmit,
+	.ndo_change_mtu = can_change_mtu,
 };
 
 static const struct ethtool_ops hi3110_ethtool_ops = {

drivers/net/can/sun4i_can.c

@@ -768,6 +768,7 @@ static const struct net_device_ops sun4ican_netdev_ops = {
 	.ndo_open = sun4ican_open,
 	.ndo_stop = sun4ican_close,
 	.ndo_start_xmit = sun4ican_start_xmit,
+	.ndo_change_mtu = can_change_mtu,
 };
 
 static const struct ethtool_ops sun4ican_ethtool_ops = {

drivers/net/can/usb/etas_es58x/es58x_core.c

@@ -7,7 +7,7 @@
  *
  * Copyright (c) 2019 Robert Bosch Engineering and Business Solutions. All rights reserved.
  * Copyright (c) 2020 ETAS K.K.. All rights reserved.
- * Copyright (c) 2020-2022 Vincent Mailhol <mailhol[email protected]>
+ * Copyright (c) 2020-2025 Vincent Mailhol <mailhol@kernel.org>
  */
 
 #include <linux/unaligned.h>
@@ -1977,6 +1977,7 @@ static const struct net_device_ops es58x_netdev_ops = {
 	.ndo_stop = es58x_stop,
 	.ndo_start_xmit = es58x_start_xmit,
 	.ndo_eth_ioctl = can_eth_ioctl_hwts,
+	.ndo_change_mtu = can_change_mtu,
 };
 
 static const struct ethtool_ops es58x_ethtool_ops = {

drivers/net/can/usb/mcba_usb.c

@@ -761,6 +761,7 @@ static const struct net_device_ops mcba_netdev_ops = {
 	.ndo_open = mcba_usb_open,
 	.ndo_stop = mcba_usb_close,
 	.ndo_start_xmit = mcba_usb_start_xmit,
+	.ndo_change_mtu = can_change_mtu,
 };
 
 static const struct ethtool_ops mcba_ethtool_ops = {