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: Jakob Koschel <jakobkoschel@gmail.com>
Link: https://lore.kernel.org/r/20220308171818.384491-12-jakobkoschel@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/udc/net2272.c b/drivers/usb/gadget/udc/net2272.c
index 7c38057..6a88846 100644 (file)
--- a/drivers/usb/gadget/udc/net2272.c
+++ b/drivers/usb/gadget/udc/net2272.c
@@ -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)
-                       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);
                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);