Re: [PATCH] [media] hdpvr: Fix an error handling path in hdpvr_probe()

From: Andrey Konovalov
Date: Fri Sep 22 2017 - 09:16:31 EST


On Fri, Sep 22, 2017 at 3:07 PM, Arvind Yadav <arvind.yadav.cs@xxxxxxxxx> wrote:
> Here, hdpvr_register_videodev() is responsible for setup and
> register a video device. Also defining and initializing a worker.
> hdpvr_register_videodev() is calling by hdpvr_probe at last.
> So No need to flash any work here.
> Unregister v4l2, free buffers and memory. If hdpvr_probe() will fail.
>
> Signed-off-by: Arvind Yadav <arvind.yadav.cs@xxxxxxxxx>

Reported-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>

Thanks, this fixes the crash!

Tested-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>

> ---
> drivers/media/usb/hdpvr/hdpvr-core.c | 26 +++++++++++++++-----------
> 1 file changed, 15 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/media/usb/hdpvr/hdpvr-core.c b/drivers/media/usb/hdpvr/hdpvr-core.c
> index dbe29c6..1e8cbaf 100644
> --- a/drivers/media/usb/hdpvr/hdpvr-core.c
> +++ b/drivers/media/usb/hdpvr/hdpvr-core.c
> @@ -292,7 +292,7 @@ static int hdpvr_probe(struct usb_interface *interface,
> /* register v4l2_device early so it can be used for printks */
> if (v4l2_device_register(&interface->dev, &dev->v4l2_dev)) {
> dev_err(&interface->dev, "v4l2_device_register failed\n");
> - goto error;
> + goto error_free_dev;
> }
>
> mutex_init(&dev->io_mutex);
> @@ -301,7 +301,7 @@ static int hdpvr_probe(struct usb_interface *interface,
> dev->usbc_buf = kmalloc(64, GFP_KERNEL);
> if (!dev->usbc_buf) {
> v4l2_err(&dev->v4l2_dev, "Out of memory\n");
> - goto error;
> + goto error_v4l2_unregister;
> }
>
> init_waitqueue_head(&dev->wait_buffer);
> @@ -339,13 +339,13 @@ static int hdpvr_probe(struct usb_interface *interface,
> }
> if (!dev->bulk_in_endpointAddr) {
> v4l2_err(&dev->v4l2_dev, "Could not find bulk-in endpoint\n");
> - goto error;
> + goto error_put_usb;
> }
>
> /* init the device */
> if (hdpvr_device_init(dev)) {
> v4l2_err(&dev->v4l2_dev, "device init failed\n");
> - goto error;
> + goto error_put_usb;
> }
>
> mutex_lock(&dev->io_mutex);
> @@ -353,7 +353,7 @@ static int hdpvr_probe(struct usb_interface *interface,
> mutex_unlock(&dev->io_mutex);
> v4l2_err(&dev->v4l2_dev,
> "allocating transfer buffers failed\n");
> - goto error;
> + goto error_put_usb;
> }
> mutex_unlock(&dev->io_mutex);
>
> @@ -361,7 +361,7 @@ static int hdpvr_probe(struct usb_interface *interface,
> retval = hdpvr_register_i2c_adapter(dev);
> if (retval < 0) {
> v4l2_err(&dev->v4l2_dev, "i2c adapter register failed\n");
> - goto error;
> + goto error_free_buffers;
> }
>
> client = hdpvr_register_ir_rx_i2c(dev);
> @@ -394,13 +394,17 @@ static int hdpvr_probe(struct usb_interface *interface,
> reg_fail:
> #if IS_ENABLED(CONFIG_I2C)
> i2c_del_adapter(&dev->i2c_adapter);
> +error_free_buffers:
> #endif
> + hdpvr_free_buffers(dev);
> +error_put_usb:
> + usb_put_dev(dev->udev);
> + kfree(dev->usbc_buf);
> +error_v4l2_unregister:
> + v4l2_device_unregister(&dev->v4l2_dev);
> +error_free_dev:
> + kfree(dev);
> error:
> - if (dev) {
> - flush_work(&dev->worker);
> - /* this frees allocated memory */
> - hdpvr_delete(dev);
> - }
> return retval;
> }
>
> --
> 1.9.1
>