Commit d0eeb4e3 authored Mar 08, 2022 by Jakob Koschel Committed by Greg Kroah-Hartman Mar 15, 2022

usb: gadget: udc-xilinx: remove usage of list iterator past the loop body

If the list representing the request queue does not contain the expected
request, the value of the list_for_each_entry() iterator will not point
to a valid structure. To avoid type confusion in such case, the list
iterator scope will be limited to the list_for_each_entry() loop.

In preparation to limiting scope of the list iterator to the list traversal
loop, use a dedicated pointer to point to the found request object [1].

Link: https://lore.kernel.org/all/YhdfEIwI4EdtHdym@kroah.com/

Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Link: https://lore.kernel.org/r/20220308171818.384491-16-jakobkoschel@gmail.com

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent b6c44bee

drivers/usb/gadget/udc/udc-xilinx.c

+8 −5

Original line number	Diff line number	Diff line
		@@ -1136,17 +1136,20 @@ static int xudc_ep_queue(struct usb_ep _ep, struct usb_request _req,
		static int xudc_ep_dequeue(struct usb_ep _ep, struct usb_request _req)
		{
		struct xusb_ep *ep = to_xusb_ep(_ep);
		struct xusb_req *req = to_xusb_req(_req);
		struct xusb_req *req = NULL;
		struct xusb_req *iter;
		struct xusb_udc *udc = ep->udc;
		unsigned long flags;

		spin_lock_irqsave(&udc->lock, flags);
		/* Make sure it's actually queued on this endpoint */
		list_for_each_entry(req, &ep->queue, queue) {
		if (&req->usb_req == _req)
		list_for_each_entry(iter, &ep->queue, queue) {
		if (&iter->usb_req != _req)
		continue;
		req = iter;
		break;
		}
		if (&req->usb_req != _req) {
		if (!req) {
		spin_unlock_irqrestore(&udc->lock, flags);
		return -EINVAL;
		}