From: Edward Adam Davis <eadavis@qq.com>
To: syzbot+031d0cfd7c362817963f@syzkaller.appspotmail.com
Cc: laurent.pinchart@ideasonboard.com, linux-kernel@vger.kernel.org,
linux-media@vger.kernel.org, mchehab@kernel.org,
sakari.ailus@linux.intel.com, syzkaller-bugs@googlegroups.com
Subject: [PATCH Next] media: mc: Clear minor number before put device
Date: Wed, 10 Sep 2025 09:15:27 +0800 [thread overview]
Message-ID: <tencent_341BA32545BAFBBB2133249EDE1B774B4908@qq.com> (raw)
In-Reply-To: <68c097c5.050a0220.3c6139.000a.GAE@google.com>
The device minor should not be cleared after the device is released.
Fixes: 9e14868dc952 ("media: mc: Clear minor number reservation at unregistration time")
Reported-by: syzbot+031d0cfd7c362817963f@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=031d0cfd7c362817963f
Tested-by: syzbot+031d0cfd7c362817963f@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
drivers/media/mc/mc-devnode.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/media/mc/mc-devnode.c b/drivers/media/mc/mc-devnode.c
index 0d01cbae98f2..6daa7aa99442 100644
--- a/drivers/media/mc/mc-devnode.c
+++ b/drivers/media/mc/mc-devnode.c
@@ -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);
}
/*
--
2.43.0
next prev parent reply other threads:[~2025-09-10 1:20 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-09-09 21:10 [syzbot] [media?] KASAN: slab-use-after-free Read in media_devnode_unregister syzbot
2025-09-10 0:42 ` Edward Adam Davis
2025-09-10 1:09 ` syzbot
2025-09-10 1:15 ` Edward Adam Davis [this message]
2025-09-10 9:22 ` [PATCH Next] media: mc: Clear minor number before put device Laurent Pinchart
2025-09-10 10:31 ` [PATCH Next V2] " Edward Adam Davis
2025-09-11 10:43 ` Sakari Ailus
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=tencent_341BA32545BAFBBB2133249EDE1B774B4908@qq.com \
--to=eadavis@qq.com \
--cc=laurent.pinchart@ideasonboard.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=mchehab@kernel.org \
--cc=sakari.ailus@linux.intel.com \
--cc=syzbot+031d0cfd7c362817963f@syzkaller.appspotmail.com \
--cc=syzkaller-bugs@googlegroups.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®