linux-kernel - [PATCH] f_midi_complete to call tasklet_hi

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-ID: <CAArt=Lib_PiR1z07hb1E3tqq-PG=KVKU9CZP3cPsQE5ciokLVw@mail.gmail.com>
Date: Thu, 6 Feb 2025 12:32:14 -0700
From: Jillian Donahue <jilliandonahue58@...il.com>
To: gregkh@...uxfoundation.org, linux-kernel@...r.kernel.org, 
	linux-usb@...r.kernel.org
Subject: [PATCH] f_midi_complete to call tasklet_hi_schedule

>From 9cb2628740d9f55f6f3faa5cce2de5eb8590f434 Mon Sep 17 00:00:00 2001
From: Jill Donahue <jilliandonahue58@...il.com>
Date: Thu, 6 Feb 2025 10:18:05 -0700
Subject: [PATCH] f_midi_complete to call tasklet_hi_schedule

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 tasklet_hi_schedule() to schedule the inner
f_midi_transmit() via a tasklet from the completion handler.

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

Fixes: d5daf49b58661 ("USB: gadget: midi: add midi function driver")
Signed-off-by: Jill Donahue <jilliandonahue58@...il.com>
---
 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 837fcdfa3..37d438e5d 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);
+                       tasklet_hi_schedule(&midi->tasklet);
                        return;
                }
                break;
-- 
2.25.1