Re: [PATCH] net: usb: rtl8150: fix memory leak on usb_submit_urb() failure

[Petko Manolov <petkan@nucleusys.com>]

On 25-12-16 20:43:05, Deepakkumar Karn wrote:
>   In async_set_registers(), when usb_submit_urb() fails, the allocated
>   async_req structure and URB are not freed, causing a memory leak.
> 
>   The completion callback async_set_reg_cb() is responsible for freeing
>   these allocations, but it is only called after the URB is successfully
>   submitted and completes (successfully or with error). If submission
>   fails, the callback never runs and the memory is leaked.
> 
>   Fix this by freeing both the URB and the request structure in the error
>   path when usb_submit_urb() fails.
> 
> Reported-by: syzbot+8dd915c7cb0490fc8c52@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=8dd915c7cb0490fc8c52
> Fixes: 4d12997a9bb3 ("drivers: net: usb: rtl8150: concurrent URB bugfix")
> Signed-off-by: Deepakkumar Karn <dkarn@redhat.com>
> ---
>  drivers/net/usb/rtl8150.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c
> index 278e6cb6f4d9..e40b0669d9f4 100644
> --- a/drivers/net/usb/rtl8150.c
> +++ b/drivers/net/usb/rtl8150.c
> @@ -211,6 +211,8 @@ static int async_set_registers(rtl8150_t *dev, u16 indx, u16 size, u16 reg)
>  		if (res == -ENODEV)
>  			netif_device_detach(dev->netdev);
>  		dev_err(&dev->udev->dev, "%s failed with %d\n", __func__, res);
> +		kfree(req);
> +		usb_free_urb(async_urb);
>  	}
>  	return res;
>  }
> -- 
> 2.52.0


ACK.

Nice catch.  This bug has been lurking for a very long time... :)


cheers,
Petko