Commit 83888411 authored by Jakob Koschel's avatar Jakob Koschel Committed by Greg Kroah-Hartman
Browse files

usb: gadget: fsl: 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/20220308171818.384491-2-jakobkoschel@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ecb0a2f1

drivers/usb/gadget/udc/fsl_qe_udc.c

+8 −5
Original line number Diff line number Diff line
@@ -1776,7 +1776,8 @@ static int qe_ep_queue(struct usb_ep *_ep, struct usb_request *_req, 
static int qe_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)

{

	struct qe_ep *ep = container_of(_ep, struct qe_ep, ep);

	struct qe_req *req;

	struct qe_req *req = NULL;

	struct qe_req *iter;

	unsigned long flags;



	if (!_ep || !_req)
@@ -1785,12 +1786,14 @@ static int qe_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req) 
	spin_lock_irqsave(&ep->udc->lock, flags);



	/* make sure it's actually 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) {

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

		return -EINVAL;

	}

drivers/usb/gadget/udc/fsl_udc_core.c

+8 −5
Original line number Diff line number Diff line
@@ -918,7 +918,8 @@ fsl_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags) 
static int fsl_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)

{

	struct fsl_ep *ep = container_of(_ep, struct fsl_ep, ep);

	struct fsl_req *req;

	struct fsl_req *req = NULL;

	struct fsl_req *iter;

	unsigned long flags;

	int ep_num, stopped, ret = 0;

	u32 epctrl;
@@ -940,11 +941,13 @@ static int fsl_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req) 
	fsl_writel(epctrl, &dr_regs->endptctrl[ep_num]);



	/* make sure it's actually 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) {

		ret = -EINVAL;

		goto out;

	}