usb: gadget: udc: net2280: 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/20220308171818.384491-13-jakobkoschel@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/udc/net2280.c b/drivers/usb/gadget/udc/net2280.c
index 16e7d2d..051d024 100644 (file)
--- a/drivers/usb/gadget/udc/net2280.c
+++ b/drivers/usb/gadget/udc/net2280.c
@@ -1240,7 +1240,8 @@ static void nuke(struct net2280_ep *ep)
 static int net2280_dequeue(struct usb_ep *_ep, struct usb_request *_req)
 {
        struct net2280_ep       *ep;
-       struct net2280_request  *req;
+       struct net2280_request  *req = NULL;
+       struct net2280_request  *iter;
        unsigned long           flags;
        u32                     dmactl;
        int                     stopped;
@@ -1266,11 +1267,13 @@ static int net2280_dequeue(struct usb_ep *_ep, struct usb_request *_req)
        }
 
        /* make sure it's still 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) {
                ep->stopped = stopped;
                spin_unlock_irqrestore(&ep->dev->lock, flags);
                ep_dbg(ep->dev, "%s: Request mismatch\n", __func__);