Messages in this thread Patch in this message | | | From | Jakob Koschel <> | Subject | [PATCH 19/26] usb: gadget: udc: max3420_udc: remove using list iterator after loop body as a ptr | Date | Sun, 6 Mar 2022 18:50:27 +0100 |
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If the list does not contain the expected element, the value of 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 list_for_each_entry() loop.
In preparation to limiting scope of a list iterator to the list traversal loop, use a dedicated pointer to point to the found element [1]. Determining if an element was found is then simply checking if the pointer is != NULL instead of using the potentially bogus pointer.
Link: https://lore.kernel.org/all/YhdfEIwI4EdtHdym@kroah.com/ Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com> --- drivers/usb/gadget/udc/max3420_udc.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/gadget/udc/max3420_udc.c b/drivers/usb/gadget/udc/max3420_udc.c index d2a2b20cc1ad..d1b010b5f4a0 100644 --- a/drivers/usb/gadget/udc/max3420_udc.c +++ b/drivers/usb/gadget/udc/max3420_udc.c @@ -1044,22 +1044,25 @@ static int max3420_ep_queue(struct usb_ep *_ep, struct usb_request *_req, static int max3420_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req) { - struct max3420_req *t, *req = to_max3420_req(_req); + struct max3420_req *t = NULL; + struct max3420_req *req = to_max3420_req(_req); + struct max3420_req *tmp; struct max3420_ep *ep = to_max3420_ep(_ep); unsigned long flags; spin_lock_irqsave(&ep->lock, flags); /* Pluck the descriptor from queue */ - list_for_each_entry(t, &ep->queue, queue) - if (t == req) { + list_for_each_entry(tmp, &ep->queue, queue) + if (tmp == req) { list_del_init(&req->queue); + t = tmp; break; } spin_unlock_irqrestore(&ep->lock, flags); - if (t == req) + if (t) max3420_req_done(req, -ECONNRESET); return 0; -- 2.25.1
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