This is a note to let you know that I've just added the patch titled
media: usbtv: Remove useless locks in usbtv_video_free()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
media-usbtv-remove-useless-locks-in-usbtv_video_free.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 646a2cf4ab79b25d33dc1e7268978be429831e4d
Author: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
Date: Sat Mar 2 11:37:08 2024 +0100
media: usbtv: Remove useless locks in usbtv_video_free()
[ Upstream commit 65e6a2773d655172143cc0b927cdc89549842895 ]
Remove locks calls in usbtv_video_free() because
are useless and may led to a deadlock as reported here:
https://syzkaller.appspot.com/x/bisect.txt?x=166dc872180000
Also remove usbtv_stop() call since it will be called when
unregistering the device.
Before 'c838530d230b' this issue would only be noticed if you
disconnect while streaming and now it is noticeable even when
disconnecting while not streaming.
Fixes: c838530d230b ("media: media videobuf2: Be more flexible on the number of queue stored buffers")
Fixes: f3d27f34fdd7 ("[media] usbtv: Add driver for Fushicai USBTV007 video frame grabber")
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxxxxxxxxx>
Reviewed-by: Tomasz Figa <tfiga@xxxxxxxxxxxx>
Tested-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
[hverkuil: fix minor spelling mistake in log message]
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/media/usb/usbtv/usbtv-video.c b/drivers/media/usb/usbtv/usbtv-video.c
index 3b4a2e7692309..f2aaec0f77c8d 100644
--- a/drivers/media/usb/usbtv/usbtv-video.c
+++ b/drivers/media/usb/usbtv/usbtv-video.c
@@ -959,15 +959,8 @@ int usbtv_video_init(struct usbtv *usbtv)
void usbtv_video_free(struct usbtv *usbtv)
{
- mutex_lock(&usbtv->vb2q_lock);
- mutex_lock(&usbtv->v4l2_lock);
-
- usbtv_stop(usbtv);
vb2_video_unregister_device(&usbtv->vdev);
v4l2_device_disconnect(&usbtv->v4l2_dev);
- mutex_unlock(&usbtv->v4l2_lock);
- mutex_unlock(&usbtv->vb2q_lock);
-
v4l2_device_put(&usbtv->v4l2_dev);
}
