Re: [PATCH] usb: musb: Fix potential NULL dereference

[Bin Liu]

On Wed, Jan 23, 2019 at 08:51:42PM +0300, Matwey V. Kornilov wrote:
> We assign "urb->hcpriv = qh;" a few lines down. The valid qh for the urb is
> hep->hcpriv in this code path.
> 
> Fixes: 714bc5ef3eda ("musb: potential use after free")
> Signed-off-by: Matwey V. Kornilov <matwey@xxxxxxxxxx>
> ---
>  drivers/usb/musb/musb_host.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
> index c6118a962d37..6f267716768e 100644
> --- a/drivers/usb/musb/musb_host.c
> +++ b/drivers/usb/musb/musb_host.c
> @@ -2336,7 +2336,7 @@ static int musb_urb_enqueue(
>  		 * odd, rare, error prone, but legal.
>  		 */
>  		kfree(qh);
> -		qh = NULL;
> +		qh = hep->hcpriv;
>  		ret = 0;
>  	} else
>  		ret = musb_schedule(musb, qh,

Did you run into any issue? The original code seems to be correct to me.

Regards,
-Bin.