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Subject[PATCH v2 15/26] usb: gadget: udc-xilinx: remove usage of list iterator past the loop body
Date
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/udc-xilinx.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/usb/gadget/udc/udc-xilinx.c b/drivers/usb/gadget/udc/udc-xilinx.c
index 2907fad04e2c..428c755cf2e1 100644
--- a/drivers/usb/gadget/udc/udc-xilinx.c
+++ b/drivers/usb/gadget/udc/udc-xilinx.c
@@ -1136,17 +1136,20 @@ static int xudc_ep_queue(struct usb_ep *_ep, struct usb_request *_req,
static int xudc_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
struct xusb_ep *ep = to_xusb_ep(_ep);
- struct xusb_req *req = to_xusb_req(_req);
+ struct xusb_req *req = NULL;
+ struct xusb_req *iter;
struct xusb_udc *udc = ep->udc;
unsigned long flags;

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->usb_req == _req)
- break;
+ list_for_each_entry(iter, &ep->queue, queue) {
+ if (&iter->usb_req != _req)
+ continue;
+ req = iter;
+ break;
}
- if (&req->usb_req != _req) {
+ if (!req) {
spin_unlock_irqrestore(&udc->lock, flags);
return -EINVAL;
}
--
2.25.1
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