lkml.org 
[lkml]   [2022]   [Mar]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 02/26] usb: gadget: bdc: 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/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 8e2f20b12519..fa88f210ecd5 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;
--
2.25.1
\
 
 \ /
  Last update: 2022-03-08 18:21    [W:0.309 / U:0.592 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site