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[net-next] can: etas_es58x: fix null pointer dereference when handling error frames

Message ID 20210414200352.2473363-2-mkl@pengutronix.de
State New
Headers show
Series [net-next] can: etas_es58x: fix null pointer dereference when handling error frames | expand

Commit Message

Marc Kleine-Budde April 14, 2021, 8:03 p.m. UTC 
From: Vincent Mailhol <mailhol.vincent@wanadoo.fr>

During the handling of CAN bus errors, a CAN error SKB is allocated
using alloc_can_err_skb(). Even if the allocation of the SKB fails,
the function continues in order to do the stats handling.

All access to the can_frame pointer (cf) should be guarded by an if
statement:
	if (cf)

However, the increment of the rx_bytes stats:
	netdev->stats.rx_bytes += cf->can_dlc;
dereferences the cf pointer and was not guarded by an if condition
leading to a NULL pointer dereference if the can_err_skb() function
failed.

Replacing the cf->can_dlc by the macro CAN_ERR_DLC (which is the
length of any CAN error frames) solves this NULL pointer dereference.

Fixes: 8537257874e9 ("can: etas_es58x: add core support for ETAS ES58X CAN USB interfaces")
Link: https://lore.kernel.org/r/20210413114242.2760-1-mailhol.vincent@wanadoo.fr
Reported-by: Arunachalam Santhanam <arunachalam.santhanam@in.bosch.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/usb/etas_es58x/es58x_core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)


base-commit: 5871d0c6b8ea805916c3135d0c53b095315bc674
diff mbox series

Patch

diff --git a/drivers/net/can/usb/etas_es58x/es58x_core.c b/drivers/net/can/usb/etas_es58x/es58x_core.c
index 7222b3b6ca46..57e5f94468e9 100644
--- a/drivers/net/can/usb/etas_es58x/es58x_core.c
+++ b/drivers/net/can/usb/etas_es58x/es58x_core.c
@@ -856,7 +856,7 @@  int es58x_rx_err_msg(struct net_device *netdev, enum es58x_err error,
 	 * consistency.
 	 */
 	netdev->stats.rx_packets++;
-	netdev->stats.rx_bytes += cf->can_dlc;
+	netdev->stats.rx_bytes += CAN_ERR_DLC;
 
 	if (cf) {
 		if (cf->data[1])