Commit 4ab37fcb authored by Jill Donahue's avatar Jill Donahue Committed by Greg Kroah-Hartman
Browse files

USB: gadget: f_midi: f_midi_complete to call queue_work 

When using USB MIDI, a lock is attempted to be acquired twice through a
re-entrant call to f_midi_transmit, causing a deadlock.

Fix it by using queue_work() to schedule the inner f_midi_transmit() via
a high priority work queue from the completion handler.

Link: https://lore.kernel.org/all/CAArt=LjxU0fUZOj06X+5tkeGT+6RbXzpWg1h4t4Fwa_KGVAX6g@mail.gmail.com/


Fixes: d5daf49b ("USB: gadget: midi: add midi function driver")
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarJill Donahue <jilliandonahue58@gmail.com>
Link: https://lore.kernel.org/r/20250211174805.1369265-1-jdonahue@fender.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4aac0db5

drivers/usb/gadget/function/f_midi.c

+1 −1
Original line number Diff line number Diff line
@@ -283,7 +283,7 @@ f_midi_complete(struct usb_ep *ep, struct usb_request *req) 
			/* Our transmit completed. See if there's more to go.

			 * f_midi_transmit eats req, don't queue it again. */

			req->length = 0;

			f_midi_transmit(midi);

			queue_work(system_highpri_wq, &midi->work);

			return;

		}

		break;