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    Subject[PATCH v2 12/26] usb: gadget: udc: net2280: 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/net2280.c | 13 ++++++++-----
    1 file changed, 8 insertions(+), 5 deletions(-)

    diff --git a/drivers/usb/gadget/udc/net2280.c b/drivers/usb/gadget/udc/net2280.c
    index 16e7d2db6411..051d024b369e 100644
    --- a/drivers/usb/gadget/udc/net2280.c
    +++ b/drivers/usb/gadget/udc/net2280.c
    @@ -1240,7 +1240,8 @@ static void nuke(struct net2280_ep *ep)
    static int net2280_dequeue(struct usb_ep *_ep, struct usb_request *_req)
    {
    struct net2280_ep *ep;
    - struct net2280_request *req;
    + struct net2280_request *req = NULL;
    + struct net2280_request *iter;
    unsigned long flags;
    u32 dmactl;
    int stopped;
    @@ -1266,11 +1267,13 @@ static int net2280_dequeue(struct usb_ep *_ep, struct usb_request *_req)
    }

    /* make sure it's still queued on this endpoint */
    - list_for_each_entry(req, &ep->queue, queue) {
    - if (&req->req == _req)
    - break;
    + list_for_each_entry(iter, &ep->queue, queue) {
    + if (&iter->req != _req)
    + continue;
    + req = iter;
    + break;
    }
    - if (&req->req != _req) {
    + if (!req) {
    ep->stopped = stopped;
    spin_unlock_irqrestore(&ep->dev->lock, flags);
    ep_dbg(ep->dev, "%s: Request mismatch\n", __func__);
    --
    2.25.1
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