From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794047444; b=SAgXK+vLukfefYvNyswmHPq5aTGI8l6zP8p9pr0Hti/nyRYB/mL86wreOrcVx+vzHX9f 10mkG+NxqJTjCw7gZ3AgJeE9kz9bSFaSWQ5U+/8nprOc4OwMpZmey8AX3aQo7PjYUkwXM zWuKWsIU5Ve4io9kZS2HzsXG0d8xoVppXg3LgEEehweO0WVhZH8DyQduZ4bWqYJ3PCKAl vlczhCHbJNzK8Ctn7MvAZSdBrdh956hgiBKHwoAL+5OuKWV0ixQ4Ch0MILILMyPIq3Fgs 0VXMFBhiXKFyCQ0mLKLpXunB590CimJgcHE2v3RzvZ2Jvw7Xcwn1NdQa3oxJlQr1vpw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794047444; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=a2m/1rfqdINrIJixiFMvgqEdneNPPQvTnSLFxRuxklc=; b=24q+fAdi7AdE9mxRmPDfuJ2nKfoBp7UK4awDOQS/F+Qt5HcqoGPjeEXazCiuE93Q7A9o Up47ouTFBzHSOblgqU2Kt+z0+i/bZii79VX4oNdHo4c4MAv021yoqL4Fs/2+QzIgHDkT4 PyyKYng7HixbRD0rYmJAedZuW2aVbBPSUfk+2cOPTPmY4Dm3Cgvlvx7Kx4x+u5Oym5C4t CPrb9z9dX0NYR7rn5rawOnMHlXVDnHs4gGXSJx96elieloIWQU5yLgxYDiMh1vfZDarvR YLZYtnh4+bNnB1CMzf9GrjGjlgrRiWkuzgKyJX48mKqKKR9dj16enSRL4BHgdI0r8Gw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=eLEoHOYC; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CC687606A326 for ; Sat, 7 Nov 2026 10:30:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=eLEoHOYC Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B2091F0089F; Sat, 7 Nov 2026 10:30:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794047443; bh=a2m/1rfqdINrIJixiFMvgqEdneNPPQvTnSLFxRuxklc=; h=From:To:Cc:Subject:Date; b=eLEoHOYC2rJkPTAhk1W2JItVftkvn9g+1CrFV3lnwfw20ih62nrTK2vhuhA0VENyp ZSbleKkxAIW9iH/FRdEvd13gks8UeeHpNtKrgS+kgd+iZbLuYP6g2KxUMNyNw7mgko sxycDxLxMjqVTeIeQiNxkkeSoiBv0Bv+fdxLhsHylygm4PyZ0e9aAGflgCE7TnVrc6 TUw7vImihIKwg3kAclurXrnjb93jlBXwtRrpXNBmxO4p3HaTlkMbVX6IQQq7809gZP ROLFMXPltk5cMZdy/7FflyzcpK5azpP5LIhAVm4kCYL7hsKzmcD9GzppkQiBbVSzaq svUljLcdz6lmg== From: Sasha Levin To: runyu.xiao@seu.edu.cn, tiwai@suse.de Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] ALSA: usb-audio: Protect Roland control activation" failed to apply to 6.6-stable tree Date: Sat, 7 Nov 2026 05:30:42 -0500 Message-ID: <20261107053042-failed-6.6-19b42c1fff7f@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 19b42c1fff7f220a6346c614d79ce1bda6d95b40 # git commit -s git send-email --to '' --in-reply-to '20261107053042-failed-6.6-19b42c1fff7f@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 19b42c1fff7f220a6346c614d79ce1bda6d95b40 Mon Sep 17 00:00:00 2001 From: Runyu Xiao Date: Tue, 29 Sep 2026 22:17:26 +0800 Subject: [PATCH] ALSA: usb-audio: Protect Roland control activation The USB MIDI driver changes the Roland MIDI Input Mode control's access flags directly from the rawmidi open and close paths. These changes are not protected by the ALSA control core and the corresponding notifications can race with control access. Use snd_ctl_activate_id() so that the control core updates the access flags and sends the notification under its lock. Release the USB MIDI mutex before calling it because the control write path holds controls_rwsem while roland_load_put() takes the USB MIDI mutex. Keep the state transition and alternate-setting change under the USB MIDI mutex; rawmidi's open mutex serializes the enclosing open and close paths. Fixes: 96f61d9ade82 ("sound: usb-audio: allow switching altsetting on Roland USB MIDI devices") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Runyu Xiao Link: https://patch.msgid.link/20260929141726.2166899-1-runyu.xiao@seu.edu.cn Signed-off-by: Takashi Iwai --- sound/usb/midi.c | 53 ++++++++++++++++++++++++------------------------ 1 file changed, 27 insertions(+), 26 deletions(-) diff --git a/sound/usb/midi.c b/sound/usb/midi.c index 0480a9b89e8f3..e3d1575540613 100644 --- a/sound/usb/midi.c +++ b/sound/usb/midi.c @@ -1150,41 +1150,42 @@ static int substream_open(struct snd_rawmidi_substream *substream, int dir, int open) { struct snd_usb_midi *umidi = substream->rmidi->private_data; - struct snd_kcontrol *ctl; + struct snd_ctl_elem_id ctl_id; + bool activate_ctl = false; + bool active; guard(rwsem_read)(&umidi->disc_rwsem); if (umidi->disconnected) return open ? -ENODEV : 0; - guard(mutex)(&umidi->mutex); - if (open) { - if (!umidi->opened[0] && !umidi->opened[1]) { - if (umidi->roland_load_ctl) { - ctl = umidi->roland_load_ctl; - ctl->vd[0].access |= - SNDRV_CTL_ELEM_ACCESS_INACTIVE; - snd_ctl_notify(umidi->card, - SNDRV_CTL_EVENT_MASK_INFO, &ctl->id); - update_roland_altsetting(umidi); + scoped_guard(mutex, &umidi->mutex) { + if (open) { + if (!umidi->opened[0] && !umidi->opened[1]) { + if (umidi->roland_load_ctl) { + ctl_id = umidi->roland_load_ctl->id; + activate_ctl = true; + active = false; + update_roland_altsetting(umidi); + } } - } - umidi->opened[dir]++; - if (umidi->opened[1]) - snd_usbmidi_input_start(&umidi->list); - } else { - umidi->opened[dir]--; - if (!umidi->opened[1] && !umidi->keep_input_running) - snd_usbmidi_input_stop(&umidi->list); - if (!umidi->opened[0] && !umidi->opened[1]) { - if (umidi->roland_load_ctl) { - ctl = umidi->roland_load_ctl; - ctl->vd[0].access &= - ~SNDRV_CTL_ELEM_ACCESS_INACTIVE; - snd_ctl_notify(umidi->card, - SNDRV_CTL_EVENT_MASK_INFO, &ctl->id); + umidi->opened[dir]++; + if (umidi->opened[1]) + snd_usbmidi_input_start(&umidi->list); + } else { + umidi->opened[dir]--; + if (!umidi->opened[1] && !umidi->keep_input_running) + snd_usbmidi_input_stop(&umidi->list); + if (!umidi->opened[0] && !umidi->opened[1]) { + if (umidi->roland_load_ctl) { + ctl_id = umidi->roland_load_ctl->id; + activate_ctl = true; + active = true; + } } } } + if (activate_ctl) + snd_ctl_activate_id(umidi->card, &ctl_id, active); return 0; } -- 2.53.0