[PATCH 4.9 11/22] usb: musb: Balance list entry in musb_gadget_queue

[Greg Kroah-Hartman]

From: Viraj Shah <viraj.shah@xxxxxxxxxxxxx>

commit 21b5fcdccb32ff09b6b63d4a83c037150665a83f upstream.

musb_gadget_queue() adds the passed request to musb_ep::req_list. If the
endpoint is idle and it is the first request then it invokes
musb_queue_resume_work(). If the function returns an error then the
error is passed to the caller without any clean-up and the request
remains enqueued on the list. If the caller enqueues the request again
then the list corrupts.

Remove the request from the list on error.

Fixes: ea2f35c01d5ea ("usb: musb: Fix sleeping function called from invalid context for hdrc glue")
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Viraj Shah <viraj.shah@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20211021093644.4734-1-viraj.shah@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/usb/musb/musb_gadget.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -1284,9 +1284,11 @@ static int musb_gadget_queue(struct usb_
 		status = musb_queue_resume_work(musb,
 						musb_ep_restart_resume_work,
 						request);
-		if (status < 0)
+		if (status < 0) {
 			dev_err(musb->controller, "%s resume work: %i\n",
 				__func__, status);
+			list_del(&request->list);
+		}
 	}
 
 unlock: