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=1794046066; b=bsgTX/IdkMHj/sjHae4/lydpZMAZ80Fg1x+bxhJTZ3eWs36l0TtVcPMj/uDQ9JPzooYz EODhrGY2EiabftCRRvkWBhOMbOuE7e622fdwX8oewimxpRfbgYnmoA5A+gEvV5sEuM4Zj Pa8CPmJ7ig2Tfr5iw7YkYOmhL1kMZugKhulttZ+ERx8fq7tNWxzi/y7ynU0YM5GcSb46H y+QXQu/LEp1hK6ty6KprTGr4OV2uR6/X7OWSUnyRr0Eny6f/2Dyknx1TD05eu5dGn9dY3 icz90Cu8dUuWYi/ugsyeY0rxaNGRmSg2c8Z+qNd1TqIUHS3J1tewneAyC6lAG23MdLQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794046066; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=GW0hYIN7+IceEmMSeevV4pIzk2+GIFsu79mR7Humawg=; b=ZbXXStVU6TyobPL9IFyrnqcjDo8zd7TVjbrZM66ly4Wd8JO6TAV0IVgv49y1QBYJKE3r YPrjb0Cz6Us1+opLZS91yY+SXFCIcyC9wgKpiXrxV77/53D8INhJqA8dUTaq29U78ndl+ VeXKgiroftT9dzf0/5icTJTwArVkSkTuxK273o00s+uOHQvj81BMc6UwGyvtP1KXSHXGv 0lK9Pg6fWi6ssxvMOGMMLgqLX9YkCO3rClMRfBbRz7z559XDbNI/iJ9R6TSckZzmszEeh R6nLo9R3FyzTzqL88fZkLxBQgt79lmiug30G3Fn1af83NO/F1/31tSagP7kGmpYZQaw== 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=gY5H3FMV; 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 AE7E8606A326 for ; Sat, 7 Nov 2026 10:07:45 +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=gY5H3FMV Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A9491F0089F; Sat, 7 Nov 2026 10:07:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794046065; bh=GW0hYIN7+IceEmMSeevV4pIzk2+GIFsu79mR7Humawg=; h=From:To:Cc:Subject:Date; b=gY5H3FMVftRNCxW1bmp6I+afKAqar/xGLhdYhrVhEzt/RHPFbS6zfkGAfJW79hyFS DW846UBegj0FqpK7ozF4lwh56gRsChjmJnVHXt7RDf+zPpuzmqnmRW525hFJQWetwf vcCk3Viug+c1KlVeV1hJ9LNGcBrdT0fi5ldw4CAm1V9ASzxsN69GNYOByRN1tL+FMP xZTz2a6q7BMftgJ6PT8BN26pCp83pq1ylqzUc1u77pylyfPhVIq/nzJKBhBpix+SKk nHrpqcW3cW7dnJxSlii09wBbDTkQre9u4d67QQWfvm2SYqPf7MHoZ9yFUNno7HJjAn OaubZHblOEERg== 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 6.18-stable tree Date: Sat, 7 Nov 2026 05:07:44 -0500 Message-ID: <20261107050744-failed-6.18-19b42c1fff7f@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 6.18-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-6.18.y git checkout FETCH_HEAD git cherry-pick -x 19b42c1fff7f220a6346c614d79ce1bda6d95b40 # git commit -s git send-email --to '' --in-reply-to '20261107050744-failed-6.18-19b42c1fff7f@kernel.org' --subject-prefix 'PATCH 6.18.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