From c6d939639fe06f1faf370fa370fe0ff62ee78ba6 Mon Sep 17 00:00:00 2001 From: Marc Kleine-Budde Date: Tue, 20 Sep 2022 11:40:56 +0200 Subject: [PATCH] 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@pengutronix.de Signed-off-by: Marc Kleine-Budde Signed-off-by: Sasha Levin --- drivers/net/can/usb/gs_usb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c index e26b3d6f5b48..5a43e542b302 100644 --- a/drivers/net/can/usb/gs_usb.c +++ b/drivers/net/can/usb/gs_usb.c @@ -680,6 +680,7 @@ 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), @@ -696,13 +697,12 @@ 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);