Hi,
changbin.du@xxxxxxxxx writes:
> From: "Du, Changbin" <changbin.du@xxxxxxxxx>
>
> Queue a request to disabled ep doesn't make sense, and induce caller
> make mistakes.
>
> Here is a example for the android mtp gadget function driver. A mem
> corruption can happen on below senario.
> 1) On disconnect, mtp driver disable its EPs,
> 2) During send_file_work and receive_file_work, mtp queues a request
> to ep. (The mtp driver need improve its synchronization logic!)
> 3) mtp_function_unbind is invoked and all mtp requests are freed.
> 4) when dwc2 process the request queued on step 2, will cause kernel
> NULL pointer dereference exception.
>
> Signed-off-by: Du, Changbin <changbin.du@xxxxxxxxx>
> ---
> drivers/usb/dwc2/gadget.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> index 586bbcd..4d637ab 100644
> --- a/drivers/usb/dwc2/gadget.c
> +++ b/drivers/usb/dwc2/gadget.c
> @@ -786,6 +786,12 @@ static int dwc2_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req,
> ep->name, req, req->length, req->buf, req->no_interrupt,
> req->zero, req->short_not_ok);
>
> + if (!hs_ep->enabled) {
> + dev_warn(hs->dev, "%s: cannot queue to disabled ep\n",
> + __func__);
similar comment to previous patch:
if (dev_WARN_ONCE(hs->dev, !hs_ep->enabled,
"cannot queue to disabled ep %s\n", hs_ep->name))
> + return -ESHUTDOWN;
> + }
> +
> /* Prevent new request submission when controller is suspended */
> if (hs->lx_state == DWC2_L2) {
> dev_dbg(hs->dev, "%s: don't submit request while suspended\n",
> --
> 2.5.0
>
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--
balbi
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