linux-kernel - [PATCH] media: usbtv: Remove useless locks in usbtv_video

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Date: Tue, 20 Feb 2024 09:06:28 +0100
From: Benjamin Gaignard <benjamin.gaignard@...labora.com>
To: mchehab@...nel.org,
	hverkuil-cisco@...all.nl,
	tfiga@...omium.org
Cc: linux-media@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	kernel@...labora.com,
	Benjamin Gaignard <benjamin.gaignard@...labora.com>
Subject: [PATCH] media: usbtv: Remove useless locks in usbtv_video_free()

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

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@...labora.com>
Fixes: c838530d230b ("media: media videobuf2: Be more flexible on the number of queue stored buffers")
---
 drivers/media/usb/usbtv/usbtv-video.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/media/usb/usbtv/usbtv-video.c b/drivers/media/usb/usbtv/usbtv-video.c
index 62a583040cd4..96276358d116 100644
--- a/drivers/media/usb/usbtv/usbtv-video.c
+++ b/drivers/media/usb/usbtv/usbtv-video.c
@@ -963,15 +963,9 @@ 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);
 }
-- 
2.40.1