From b6af554427adf9b5960295305d698442680f7caa Mon Sep 17 00:00:00 2001 From: Jakob Koschel Date: Tue, 8 Mar 2022 18:17:54 +0100 Subject: [PATCH] usb: gadget: bdc: 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 Link: https://lore.kernel.org/r/20220308171818.384491-3-jakobkoschel@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/udc/bdc/bdc_ep.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/drivers/usb/gadget/udc/bdc/bdc_ep.c b/drivers/usb/gadget/udc/bdc/bdc_ep.c index 8e2f20b..fa88f21 100644 --- a/drivers/usb/gadget/udc/bdc/bdc_ep.c +++ b/drivers/usb/gadget/udc/bdc/bdc_ep.c @@ -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; -- 2.7.4