Commit 4cb42217 authored by Felipe Balbi's avatar Felipe Balbi

usb: dwc3: gadget: fix for possible endpoint disable race

when we call dwc3_gadget_giveback(), we end up
releasing our controller's lock. Another thread
could get scheduled and disable the endpoint,
subsequently setting dep->endpoint.desc to NULL.

In that case, we would end up dereferencing a NULL
pointer which would result in a Kernel Oops. Let's
avoid the problem by simply returning early if we
have a NULL descriptor.
Signed-off-by: default avatarFelipe Balbi <felipe.balbi@linux.intel.com>
parent 9cad39fe
......@@ -2041,6 +2041,14 @@ static int dwc3_cleanup_done_reqs(struct dwc3 *dwc, struct dwc3_ep *dep,
break;
} while (1);
/*
* Our endpoint might get disabled by another thread during
* dwc3_gadget_giveback(). If that happens, we're just gonna return 1
* early on so DWC3_EP_BUSY flag gets cleared
*/
if (!dep->endpoint.desc)
return 1;
if (usb_endpoint_xfer_isoc(dep->endpoint.desc) &&
list_empty(&dep->started_list)) {
if (list_empty(&dep->pending_list)) {
......@@ -2078,7 +2086,7 @@ static void dwc3_endpoint_transfer_complete(struct dwc3 *dwc,
status = -ECONNRESET;
clean_busy = dwc3_cleanup_done_reqs(dwc, dep, event, status);
if (clean_busy && (is_xfer_complete ||
if (clean_busy && (!dep->endpoint.desc || is_xfer_complete ||
usb_endpoint_xfer_isoc(dep->endpoint.desc)))
dep->flags &= ~DWC3_EP_BUSY;
......@@ -2107,6 +2115,14 @@ static void dwc3_endpoint_transfer_complete(struct dwc3 *dwc,
dwc->u1u2 = 0;
}
/*
* Our endpoint might get disabled by another thread during
* dwc3_gadget_giveback(). If that happens, we're just gonna return 1
* early on so DWC3_EP_BUSY flag gets cleared
*/
if (!dep->endpoint.desc)
return;
if (!usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
int ret;
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment