diff mbox series

[02/26] usb: gadget: bdc: remove usage of list iterator past the loop body

Message ID 20220306175034.3084609-3-jakobkoschel@gmail.com
State Superseded
Headers show
Series usb: gadget: remove usage of list iterator past the loop | expand

Commit Message

Jakob Koschel March 6, 2022, 5:50 p.m. UTC
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>
---
 drivers/usb/gadget/udc/bdc/bdc_ep.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/usb/gadget/udc/bdc/bdc_ep.c b/drivers/usb/gadget/udc/bdc/bdc_ep.c
index 8e2f20b12519..829e96791d0a 100644
--- a/drivers/usb/gadget/udc/bdc/bdc_ep.c
+++ b/drivers/usb/gadget/udc/bdc/bdc_ep.c
@@ -1757,6 +1757,7 @@  static int bdc_gadget_ep_dequeue(struct usb_ep *_ep,
 				  struct usb_request *_req)
 {
 	struct bdc_req *req;
+	struct bdc_req *tmp;
 	unsigned long flags;
 	struct bdc_ep *ep;
 	struct bdc *bdc;
@@ -1771,12 +1772,16 @@  static int bdc_gadget_ep_dequeue(struct usb_ep *_ep,
 	dev_dbg(bdc->dev, "%s ep:%s req:%p\n", __func__, ep->name, req);
 	bdc_dbg_bd_list(bdc, ep);
 	spin_lock_irqsave(&bdc->lock, flags);
+
+	req = NULL;
 	/* make sure it's still queued on this endpoint */
-	list_for_each_entry(req, &ep->queue, queue) {
-		if (&req->usb_req == _req)
+	list_for_each_entry(tmp, &ep->queue, queue) {
+		if (&tmp->usb_req == _req) {
+			req = tmp;
 			break;
+		}
 	}
-	if (&req->usb_req != _req) {
+	if (!req) {
 		spin_unlock_irqrestore(&bdc->lock, flags);
 		dev_err(bdc->dev, "usb_req !=req n");
 		return -EINVAL;