Commit e6169a87 authored by Jakob Koschel's avatar Jakob Koschel Committed by Greg Kroah-Hartman
Browse files

usb: gadget: net2272: 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: default avatarJakob Koschel <jakobkoschel@gmail.com>
Link: https://lore.kernel.org/r/20220308171818.384491-12-jakobkoschel@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ac7a5d05

drivers/usb/gadget/udc/net2272.c

+7 −6
Original line number Diff line number Diff line
@@ -926,7 +926,7 @@ static int 
net2272_dequeue(struct usb_ep *_ep, struct usb_request *_req)

{

	struct net2272_ep *ep;

	struct net2272_request *req;

	struct net2272_request *req = NULL, *iter;

	unsigned long flags;

	int stopped;
@@ -939,11 +939,13 @@ net2272_dequeue(struct usb_ep *_ep, struct usb_request *_req) 
	ep->stopped = 1;



	/* make sure it's still queued on this endpoint */

	list_for_each_entry(req, &ep->queue, queue) {

		if (&req->req == _req)

	list_for_each_entry(iter, &ep->queue, queue) {

		if (&iter->req != _req)

			continue;

		req = iter;

		break;

	}

	if (&req->req != _req) {

	if (!req) {

		ep->stopped = stopped;

		spin_unlock_irqrestore(&ep->dev->lock, flags);

		return -EINVAL;
@@ -954,7 +956,6 @@ net2272_dequeue(struct usb_ep *_ep, struct usb_request *_req) 
		dev_dbg(ep->dev->dev, "unlink (%s) pio\n", _ep->name);

		net2272_done(ep, req, -ECONNRESET);

	}

	req = NULL;

	ep->stopped = stopped;



	spin_unlock_irqrestore(&ep->dev->lock, flags);