github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-30 11:11:26 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

can: gs_usb: gs_can_open(): initialize time counter before starting device

Browse Source 
On busy networks the CAN controller might receive CAN frames directly
after starting it but before the timecounter is setup. This will lead
to NULL pointer deref while converting the converting the CAN frame's
timestamp with the timecounter.

Close the race window by setting up the timecounter before starting
the CAN controller.

Fixes: 45dfa45f52 ("can: gs_usb: add RX and TX hardware timestamp support")
Link: https://lore.kernel.org/all/20220921081329.385509-1-mkl@pengutronix.de
Cc: John Whittington <git@jbrengineering.co.uk
Tested-by: John Whittington <git@jbrengineering.co.uk>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Marc Kleine-Budde 2022-09-20 11:46:12 +02:00
parent 29a8c9ec90
commit 103108cb96
1 changed files with 6 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/net/can/usb/gs_usb.c
View File

@ -972,6 +972,10 @@ static int gs_can_open(struct net_device *netdev)
if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
flags |= GS_CAN_MODE_HW_TIMESTAMP;
/* start polling timestamp */
if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
gs_usb_timestamp_init(dev);
/* finally start device */
dev->can.state = CAN_STATE_ERROR_ACTIVE;
dm->mode = cpu_to_le32(GS_CAN_MODE_START);
@ -985,16 +989,14 @@ 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);
if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
gs_usb_timestamp_stop(dev);
dev->can.state = CAN_STATE_STOPPED;
return rc;
}
kfree(dm);
/* start polling timestamp */
if (dev->feature & GS_CAN_FEATURE_HW_TIMESTAMP)
gs_usb_timestamp_init(dev);
parent->active_channels++;
if (!(dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
netif_start_queue(netdev);