From: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
commit 4bc60736154bc9e0e39d3b88918f5d3762ebe5e0 upstream.
First the media device node was created, and if successful it was
marked as 'registered'. This leaves a small race condition where
an application can open the device node and get an error back
because the 'registered' flag was not yet set.
Change the order: first set the 'registered' flag, then actually
register the media device node. If that fails, then clear the flag.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Fixes: cf4b9211b568 ("[media] media: Media device node support")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/media/mc/mc-devnode.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
--- a/drivers/media/mc/mc-devnode.c
+++ b/drivers/media/mc/mc-devnode.c
@@ -245,15 +245,14 @@ int __must_check media_devnode_register(
kobject_set_name(&devnode->cdev.kobj, "media%d", devnode->minor);
/* Part 3: Add the media and char device */
+ set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
ret = cdev_device_add(&devnode->cdev, &devnode->dev);
if (ret < 0) {
+ clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
pr_err("%s: cdev_device_add failed\n", __func__);
goto cdev_add_error;
}
- /* Part 4: Activate this minor. The char device can now be used. */
- set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
-
return 0;
cdev_add_error:
Patches currently in stable-queue which might be from hverkuil-cisco@xxxxxxxxx are
queue-6.9/media-mgb4-fix-double-debugfs-remove.patch
queue-6.9/media-mc-fix-graph-walk-in-media_pipeline_start.patch
queue-6.9/media-ov2740-fix-link_freq-and-pixel_rate-control-value-reporting.patch
queue-6.9/media-v4l-async-fix-notifier-list-entry-init.patch
queue-6.9/media-v4l-async-don-t-set-notifier-s-v4l2-device-if-registering-fails.patch
queue-6.9/media-mc-mark-the-media-devnode-as-registered-from-the-start.patch
queue-6.9/media-v4l-async-properly-re-initialise-notifier-entry-in-unregister.patch
queue-6.9/media-v4l2-core-hold-videodev_lock-until-dev-reg-finishes.patch
