By the way, why do we need to store the qh in urb->hcpriv?
qh can always be accessible through urb->ep->hcpriv
Wouldn't it be better to drop entire urb->hcpriv usage?
ср, 23 янв. 2019 г. в 20:52, Matwey V. Kornilov <matwey@xxxxxxxxxx>:
>
> 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,
> --
> 2.16.4
>
--
With best regards,
Matwey V. Kornilov
