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can: dev: fix skb drop check

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In commit a6d190f8c7 ("can: skb: drop tx skb if in listen only
mode") the priv->ctrlmode element is read even on virtual CAN
interfaces that do not create the struct can_priv at startup. This
out-of-bounds read may lead to CAN frame drops for virtual CAN
interfaces like vcan and vxcan.

This patch mainly reverts the original commit and adds a new helper
for CAN interface drivers that provide the required information in
struct can_priv.

Fixes: a6d190f8c7 ("can: skb: drop tx skb if in listen only mode")
Reported-by: Dariusz Stojaczyk <Dariusz.Stojaczyk@opensynergy.com>
Cc: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Cc: Max Staudt <max@enpas.org>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20221102095431.36831-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org # 6.0.x
[mkl: patch pch_can, too]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Oliver Hartkopp
2022-11-02 10:54:31 +01:00
committed by Marc Kleine-Budde
parent 3eb3d283e8
commit ae64438be1
36 changed files with 51 additions and 43 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/net/can/dev/skb.c
View File

@@ -5,7 +5,6 @@
*/
#include <linux/can/dev.h>
#include <linux/can/netlink.h>
#include <linux/module.h>
#define MOD_DESC "CAN device driver interface"
@@ -337,8 +336,6 @@ static bool can_skb_headroom_valid(struct net_device *dev, struct sk_buff *skb)
/* Drop a given socketbuffer if it does not contain a valid CAN frame. */
bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb)
{
struct can_priv *priv = netdev_priv(dev);
switch (ntohs(skb->protocol)) {
case ETH_P_CAN:
if (!can_is_can_skb(skb))
@@ -359,13 +356,8 @@ bool can_dropped_invalid_skb(struct net_device *dev, struct sk_buff *skb)
goto inval_skb;
}
if (!can_skb_headroom_valid(dev, skb)) {
if (!can_skb_headroom_valid(dev, skb))
goto inval_skb;
} else if (priv->ctrlmode & CAN_CTRLMODE_LISTENONLY) {
netdev_info_once(dev,
"interface in listen only mode, dropping skb\n");
goto inval_skb;
}
return false;