[PATCH] media: stkwebcam: Use usb_get_dev() for the reference count of udev

-----Original Message-----
From: Cai,Huoqing <redacted>
Sent: 2021年8月2日 14:42
To: mchehab@kernel.org; hverkuil-cisco@xs4all.nl; paskripkin@gmail.com
Cc: linux-media@vger.kernel.org; Cai,Huoqing <redacted>
Subject: [PATCH] media: stkwebcam: Use usb_get_dev() for the reference count
of udev

Use usb_get_dev() to increment the reference count of the usb device structure
in order to avoid releasing the structure while it is still in use. And use
usb_put_dev() to decrement the reference count and thus, when it will be equal
to 0 the structure will be released.

Reported-by: Salah Triki <salah.triki@gmail.com>
Signed-off-by: Cai Huoqing <redacted>
---
 drivers/media/usb/stkwebcam/stk-webcam.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c

b/drivers/media/usb/stkwebcam/stk-webcam.c
index 0e231e576dc3..b54a23c6842e 100644

--- a/drivers/media/usb/stkwebcam/stk-webcam.c
+++ b/drivers/media/usb/stkwebcam/stk-webcam.c

@@ -1234,6 +1234,7 @@ static void stk_v4l_dev_release(struct video_device

*vd)
 	if (dev->sio_bufs != NULL || dev->isobufs != NULL)
 		pr_err("We are leaking memory\n");
 	usb_put_intf(dev->interface);
+	usb_put_dev(dev->udev);
 }

 static const struct video_device stk_v4l_data = { @@ -1309,7 +1310,7 @@
static int stk_camera_probe(struct usb_interface *interface,
 	init_waitqueue_head(&dev->wait_frame);
 	dev->first_init = 1; /* webcam LED management */

-	dev->udev = udev;
+	dev->udev = usb_get_dev(udev);
 	dev->interface = interface;
 	usb_get_intf(interface);

--
2.25.1