2016-04-22 22:07:04

by Alexey Khoroshilov

Subject: [PATCH] [media] au0828: fix double free in au0828_usb_probe()

In case of failure au0828_v4l2_device_register() deallocates dev
and returns error code to au0828_usb_probe(), which also
calls kfree(dev) on a failure path.

The patch removes duplicated code from au0828_v4l2_device_register().

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Alexey Khoroshilov <[email protected]>
---
drivers/media/usb/au0828/au0828-video.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/drivers/media/usb/au0828/au0828-video.c b/drivers/media/usb/au0828/au0828-video.c
index 32d7db96479c..7d0ec4cb248c 100644
--- a/drivers/media/usb/au0828/au0828-video.c
+++ b/drivers/media/usb/au0828/au0828-video.c
@@ -679,8 +679,6 @@ int au0828_v4l2_device_register(struct usb_interface *interface,
if (retval) {
pr_err("%s() v4l2_device_register failed\n",
__func__);
- mutex_unlock(&dev->lock);
- kfree(dev);
return retval;
}

@@ -691,8 +689,6 @@ int au0828_v4l2_device_register(struct usb_interface *interface,
if (retval) {
pr_err("%s() v4l2_ctrl_handler_init failed\n",
__func__);
- mutex_unlock(&dev->lock);
- kfree(dev);
return retval;
}
dev->v4l2_dev.ctrl_handler = &dev->v4l2_ctrl_hdl;
--
1.9.1

2016-04-25 14:20:53

by Shuah Khan

Subject: Re: [PATCH] [media] au0828: fix double free in au0828_usb_probe()

On 04/22/2016 04:05 PM, Alexey Khoroshilov wrote:
> In case of failure au0828_v4l2_device_register() deallocates dev
> and returns error code to au0828_usb_probe(), which also
> calls kfree(dev) on a failure path.
>
> The patch removes duplicated code from au0828_v4l2_device_register().
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <[email protected]>

I sent a fix in for this a few weeks ago:

https://lkml.org/lkml/2016/3/28/453

thanks,
-- Shuah

> ---
> drivers/media/usb/au0828/au0828-video.c | 4 ----
> 1 file changed, 4 deletions(-)
>
> diff --git a/drivers/media/usb/au0828/au0828-video.c b/drivers/media/usb/au0828/au0828-video.c
> index 32d7db96479c..7d0ec4cb248c 100644
> --- a/drivers/media/usb/au0828/au0828-video.c
> +++ b/drivers/media/usb/au0828/au0828-video.c
> @@ -679,8 +679,6 @@ int au0828_v4l2_device_register(struct usb_interface *interface,
> if (retval) {
> pr_err("%s() v4l2_device_register failed\n",
> __func__);
> - mutex_unlock(&dev->lock);
> - kfree(dev);
> return retval;
> }
>
> @@ -691,8 +689,6 @@ int au0828_v4l2_device_register(struct usb_interface *interface,
> if (retval) {
> pr_err("%s() v4l2_ctrl_handler_init failed\n",
> __func__);
> - mutex_unlock(&dev->lock);
> - kfree(dev);
> return retval;
> }
> dev->v4l2_dev.ctrl_handler = &dev->v4l2_ctrl_hdl;
>