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usb: gadget: bdc: remove usage of list iterator past the loop body

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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/20220308171818.384491-3-jakobkoschel@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jakob Koschel 2022-03-08 18:17:54 +01:00 committed by Greg Kroah-Hartman
parent 838884110f
commit b6af554427
1 changed files with 9 additions and 4 deletions
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13
drivers/usb/gadget/udc/bdc/bdc_ep.c
View file

@ -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 *iter;
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)
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(&bdc->lock, flags);
dev_err(bdc->dev, "usb_req !=req n");
return -EINVAL;