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FAILED: patch "[PATCH] media: mc: Clear minor number before put device" failed to apply to 5.10-stable tree

PATCH New [email protected] 2 participants 2 messages Oct 13, 2025

Subsystems (3)
Stable branch Media (V4L/DVB) Media controller framework
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author maintainer
#0 lore raw

The patch below does not apply to the 5.10-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 <[email protected]>.

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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 8cfc8cec1b4da88a47c243a11f384baefd092a50
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025101339-polygraph-crept-0130@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

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

From 8cfc8cec1b4da88a47c243a11f384baefd092a50 Mon Sep 17 00:00:00 2001
From: Edward Adam Davis <[email protected]>
Date: Wed, 10 Sep 2025 09:15:27 +0800
Subject: [PATCH] media: mc: Clear minor number before put device

The device minor should not be cleared after the device is released.

Fixes 9e14868dc952 ("media: mc: Clear minor number reservation at unregistration time")
Cc [email protected]
Reported-by [email protected]
Closes https://syzkaller.appspot.com/bug?extid=031d0cfd7c362817963f
Tested-by [email protected]
Signed-off-by Edward Adam Davis <[email protected]>
Signed-off-by Sakari Ailus <[email protected]>
Signed-off-by Hans Verkuil <[email protected]>
drivers/media/mc/mc-devnode.c +1 -4
index 0d01cbae98f2..6daa7aa99442 100644
@@ -276,13 +276,10 @@ void media_devnode_unregister(struct media_devnode *devnode)
 	/* Delete the cdev on this minor as well */
 	cdev_device_del(&devnode->cdev, &devnode->dev);
 	devnode->media_dev = NULL;
+	clear_bit(devnode->minor, media_devnode_nums);
 	mutex_unlock(&media_devnode_lock);
 
 	put_device(&devnode->dev);
-
-	mutex_lock(&media_devnode_lock);
-	clear_bit(devnode->minor, media_devnode_nums);
-	mutex_unlock(&media_devnode_lock);
 }
 
 /*
maintainer
#1 lore raw

PATCH 1/1 media: mc: Clear minor number before put device

From: Edward Adam Davis <[email protected]>

[ Upstream commit 8cfc8cec1b4da88a47c243a11f384baefd092a50 ]

The device minor should not be cleared after the device is released.

Fixes 9e14868dc952 ("media: mc: Clear minor number reservation at unregistration time")
Cc [email protected]
Reported-by [email protected]
Closes https://syzkaller.appspot.com/bug?extid=031d0cfd7c362817963f
Tested-by [email protected]
Signed-off-by Edward Adam Davis <[email protected]>
Signed-off-by Sakari Ailus <[email protected]>
Signed-off-by Hans Verkuil <[email protected]>
[ moved clear_bit from media_devnode_release callback to media_devnode_unregister before put_device ]
Signed-off-by Sasha Levin <[email protected]>
---
 drivers/media/mc/mc-devnode.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)
drivers/media/mc/mc-devnode.c +1 -5
index f249199dc616b..f8257aa5fc584 100644
@@ -50,11 +50,6 @@ static void media_devnode_release(struct device *cd)
 {
 	struct media_devnode *devnode = to_media_devnode(cd);
 
-	mutex_lock(&media_devnode_lock);
-	/* Mark device node number as free */
-	clear_bit(devnode->minor, media_devnode_nums);
-	mutex_unlock(&media_devnode_lock);
-
 	/* Release media_devnode and perform other cleanups as needed. */
 	if (devnode->release)
 		devnode->release(devnode);

@@ -283,6 +278,7 @@ void media_devnode_unregister(struct media_devnode *devnode)
 	/* Delete the cdev on this minor as well */
 	cdev_device_del(&devnode->cdev, &devnode->dev);
 	devnode->media_dev = NULL;
+	clear_bit(devnode->minor, media_devnode_nums);
 	mutex_unlock(&media_devnode_lock);
 
 	put_device(&devnode->dev);
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