From: Jill Donahue jilliandonahue58@gmail.com
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_KGVA... Fixes: d5daf49b58661 ("USB: gadget: midi: add midi function driver") Cc: stable@vger.kernel.org Signed-off-by: Jill Donahue jilliandonahue58@gmail.com --- V3 -> V4: Adjusted changes based on latest kernel tree
drivers/usb/gadget/function/f_midi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c index 837fcdfa3840..a188648d7528 100644 --- a/drivers/usb/gadget/function/f_midi.c +++ b/drivers/usb/gadget/function/f_midi.c @@ -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;