This is a note to let you know that I've just added the patch titled
can: gs_usb: gs_can_open(): fix race dev->can.state condition
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
can-gs_usb-gs_can_open-fix-race-dev-can.state-condit.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 68d555970a7c9b74f1aa7572e678b544284a2aa9
Author: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Date: Tue Sep 20 11:40:56 2022 +0200
can: gs_usb: gs_can_open(): fix race dev->can.state condition
[ Upstream commit 5440428b3da65408dba0241985acb7a05258b85e ]
The dev->can.state is set to CAN_STATE_ERROR_ACTIVE, after the device
has been started. On busy networks the CAN controller might receive
CAN frame between and go into an error state before the dev->can.state
is assigned.
Assign dev->can.state before starting the controller to close the race
window.
Fixes: d08e973a77d1 ("can: gs_usb: Added support for the GS_USB CAN devices")
Link: https://lore.kernel.org/all/20220920195216.232481-1-mkl@xxxxxxxxxxxxxx
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index 1bfc497da9ac..a879200eaab0 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -678,6 +678,7 @@ static int gs_can_open(struct net_device *netdev)
flags |= GS_CAN_MODE_TRIPLE_SAMPLE;
/* finally start device */
+ dev->can.state = CAN_STATE_ERROR_ACTIVE;
dm->mode = cpu_to_le32(GS_CAN_MODE_START);
dm->flags = cpu_to_le32(flags);
rc = usb_control_msg(interface_to_usbdev(dev->iface),
@@ -694,13 +695,12 @@ static int gs_can_open(struct net_device *netdev)
if (rc < 0) {
netdev_err(netdev, "Couldn't start device (err=%d)\n", rc);
kfree(dm);
+ dev->can.state = CAN_STATE_STOPPED;
return rc;
}
kfree(dm);
- dev->can.state = CAN_STATE_ERROR_ACTIVE;
-
parent->active_channels++;
if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
netif_start_queue(netdev);
