FAILED: patch "[PATCH] media: mc: mark the media devnode as registered from the," failed to apply to 4.19-stable tree

FAILED: patch "[PATCH] media: mc: mark the media devnode as registered from the," failed to apply to 4.19-stable tree

[gregkh]

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x 4bc60736154bc9e0e39d3b88918f5d3762ebe5e0
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2024061207-grooving-scholar-3378@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..

Possible dependencies:

4bc60736154b ("media: mc: mark the media devnode as registered from the, start")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 4bc60736154bc9e0e39d3b88918f5d3762ebe5e0 Mon Sep 17 00:00:00 2001
From: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Date: Fri, 23 Feb 2024 09:46:19 +0100
Subject: [PATCH] media: mc: mark the media devnode as registered from the,
 start

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@xs4all.nl>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Fixes: cf4b9211b568 ("[media] media: Media device node support")
Cc: stable@vger.kernel.org
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

diff --git a/drivers/media/mc/mc-devnode.c b/drivers/media/mc/mc-devnode.c
index 7f67825c8757..318e267e798e 100644
--- a/drivers/media/mc/mc-devnode.c
+++ b/drivers/media/mc/mc-devnode.c
@@ -245,15 +245,14 @@ int __must_check media_devnode_register(struct media_device *mdev,
 	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: