4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
[ Upstream commit 4bc60736154bc9e0e39d3b88918f5d3762ebe5e0 ]
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: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/media/media-devnode.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/media/media-devnode.c b/drivers/media/media-devnode.c
index 6b87a721dc499..b4a62b3172e3d 100644
--- a/drivers/media/media-devnode.c
+++ b/drivers/media/media-devnode.c
@@ -253,15 +253,14 @@ int __must_check media_devnode_register(struct media_device *mdev,
devnode->cdev.owner = owner;
/* 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:
--
2.43.0
