diff mbox series

[v2,05/26] usb: gadget: udc: at91: remove usage of list iterator past the loop body

Message ID 20220308171818.384491-6-jakobkoschel@gmail.com
State New
Headers show
Series usb: gadget: remove usage of list iterator past the loop | expand

Commit Message

Jakob Koschel March 8, 2022, 5:17 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/at91_udc.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/drivers/usb/gadget/udc/at91_udc.c b/drivers/usb/gadget/udc/at91_udc.c
index 9040a0561466..728987280373 100644
--- a/drivers/usb/gadget/udc/at91_udc.c
+++ b/drivers/usb/gadget/udc/at91_udc.c
@@ -704,7 +704,7 @@  static int at91_ep_queue(struct usb_ep *_ep,
 static int at91_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
 {
 	struct at91_ep		*ep;
-	struct at91_request	*req;
+	struct at91_request	*req = NULL, *iter;
 	unsigned long		flags;
 	struct at91_udc		*udc;
 
@@ -717,11 +717,13 @@  static int at91_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
 	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->req == _req)
-			break;
+	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(&udc->lock, flags);
 		return -EINVAL;
 	}