Re: [PATCH] rtl8187: fix use after free on failure path in rtl8187_probe()

[Hin-Tak Leung <htl10@users.sourceforge.net>]

------------------------------
On Sun, Mar 30, 2014 10:31 PM BST Larry Finger wrote:

>On 03/28/2014 03:26 PM, Alexey Khoroshilov wrote:
> If allocation of io_dmabuf fails, rtl8187_probe() calls usb_put_dev(udev)
> while usb_get_dev(udev) is not called yet. As a result refcnt is decremented
> incorrectly and usb_dev can be used after memory deallocation.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
> ---
>
>Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
>
>Thanks,
>
>Larry

Acked-by: Hin-Tak Leung <htl10@users.sourceforge.net>

Hin-Tak

>
>   drivers/net/wireless/rtl818x/rtl8187/dev.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/rtl818x/rtl8187/dev.c b/drivers/net/wireless/rtl818x/rtl8187/dev.c
> index fd78df813a85..d7f540a9dc9b 100644
> --- a/drivers/net/wireless/rtl818x/rtl8187/dev.c
> +++ b/drivers/net/wireless/rtl818x/rtl8187/dev.c
> @@ -1636,10 +1636,10 @@ static int rtl8187_probe(struct usb_interface *intf,
>
>    err_free_dmabuf:
>       kfree(priv->io_dmabuf);
> - err_free_dev:
> -    ieee80211_free_hw(dev);
>       usb_set_intfdata(intf, NULL);
>       usb_put_dev(udev);
> + err_free_dev:
> +    ieee80211_free_hw(dev);
>       return err;
>   }
>
>
>