From cf3748b323c3899cf19ba541c4469984d0fbf1a2 Mon Sep 17 00:00:00 2001 From: Cole Munz Date: Sat, 1 Aug 2026 01:38:16 -0500 Subject: [PATCH] usb: dwc3: gadget: don't error on dequeue of a completed request Dequeuing a request that has already been given back logs an error and returns -EINVAL: dwc3 23000000.usb: request 00000000ad92f1c4 was not queued to ep0out f_fs hits this on every teardown. functionfs_unbind() dequeues ep0req unconditionally before freeing it, which commit ce405d561b02 ("usb: gadget: f_fs: Ensure ep0req is dequeued before free_request") made deliberate to close a use-after-free. By then the control transfer has long completed, so dwc3_gadget_ep_dequeue() finds the request on none of cancelled_list, pending_list or started_list and falls through to the error path. Nothing is actually wrong. The request is not queued, which is what the caller asked for, and both callers ignore the return value and free the request straight after. The only effect is an error line in every gadget teardown, which buries real USB errors. dwc3 already tracks enough to tell the two cases apart. dwc3_gadget_ep_alloc_request() sets DWC3_REQUEST_STATUS_UNKNOWN, both __dwc3_gadget_ep_queue() and __dwc3_gadget_ep0_queue() set DWC3_REQUEST_STATUS_QUEUED, and dwc3_gadget_giveback() sets DWC3_REQUEST_STATUS_COMPLETED. A request that reaches the end of dequeue with status COMPLETED was queued to this endpoint and has finished. Anything else was never queued here, or the driver lost track of it. Keep the error for those, and return success for a completed request. This is narrower than the cdnsp fix for the same caller, commit 34f08eb0ba6e ("usb: cdnsp: Fixes issue with dequeuing not queued requests"), which returns 0 whenever usb_request::status is not -EINPROGRESS. That also swallows a request that was never queued, since status is zero out of allocation. Going by dwc3's own request status keeps that case an error, which is what was asked for when a separate ep0 dequeue was proposed in 2022. Link: https://lore.kernel.org/linux-usb/20221117054917.30104-1-quic_ugoswami@quicinc.com/ Signed-off-by: Cole Munz --- drivers/usb/dwc3/gadget.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 1082e9c9afaa89..10861269a26e77 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -2181,9 +2181,20 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep, } } - dev_err(dwc->dev, "request %p was not queued to %s\n", - request, ep->name); - ret = -EINVAL; + /* + * The request is on none of this endpoint's lists. That is the + * expected state once it has been given back: a function may dequeue + * a request before freeing it, and f_fs does so unconditionally for + * ep0req in functionfs_unbind(). Nothing is queued, which is what the + * caller asked for, so report success. Any other status means the + * request was never queued here or the driver lost track of it, and + * stays an error. + */ + if (req->status != DWC3_REQUEST_STATUS_COMPLETED) { + dev_err(dwc->dev, "request %p was not queued to %s\n", + request, ep->name); + ret = -EINVAL; + } out: spin_unlock_irqrestore(&dwc->lock, flags);