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

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

[Cai Huoqing]

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 <caihuoqing@baidu.com>
---
 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

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

[Cai,Huoqing]

Hello, Salah
I  have read  your patch
https://lore.kernel.org/patchwork/patch/1466782/
so I try to fix the same issue in stkwebcam:
may I add "Reported-by: Salah Triki <salah.triki@gmail.com>"
ask for your comfirmation
if not, I will remove it.

> -----Original Message-----
> From: Cai,Huoqing <caihuoqing@baidu.com>
> 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 <caihuoqing@baidu.com>
> 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 <caihuoqing@baidu.com>
> ---
>  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

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

[Cai Huoqing]

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 <caihuoqing@baidu.com>
---
 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