From: "Du, Changbin" <changbin.du@xxxxxxxxx>
Queue a request to disabled ep doesn't make sense, and induce caller
make mistakes.
Here is a example for the android mtp gadget function driver. A mem
corruption can happen on below senario.
1) On disconnect, mtp driver disable its EPs,
2) During send_file_work and receive_file_work, mtp queues a request
to ep. (The mtp driver need improve its synchronization logic!)
3) mtp_function_unbind is invoked and all mtp requests are freed.
4) when dwc2 process the request queued on step 2, will cause kernel
NULL pointer dereference exception.
Signed-off-by: Du, Changbin <changbin.du@xxxxxxxxx>
---
drivers/usb/dwc2/gadget.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 586bbcd..4d637ab 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -786,6 +786,12 @@ static int dwc2_hsotg_ep_queue(struct usb_ep *ep, struct usb_request *req,
ep->name, req, req->length, req->buf, req->no_interrupt,
req->zero, req->short_not_ok);
+ if (!hs_ep->enabled) {
+ dev_warn(hs->dev, "%s: cannot queue to disabled ep\n",
+ __func__);
+ return -ESHUTDOWN;
+ }
+
/* Prevent new request submission when controller is suspended */
if (hs->lx_state == DWC2_L2) {
dev_dbg(hs->dev, "%s: don't submit request while suspended\n",
--
2.5.0
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