From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EEAD13E559C for ; Tue, 25 Aug 2026 08:28:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787646528; cv=none; b=tL7/dpMd3iS87Qv0ODdR8YIbJG/fQQJO7ABt8Kw8tccPhzv8VpyDfAuK3vFJdtqy+9n67xXe8vBu5pET3/1deKPmXF9n7554Yk2wa6QgLfuOvD3UoclNMICGJwSK2jHviFEfHfXdvnk4xST9M+cKTMbkpSA2pxjCLLRGURDxaxI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787646528; c=relaxed/simple; bh=O5hpInFvfc14DjYaeDAOoPBWveVvqnxG8FDaQf1BQIg=; h=From:To:Subject:Date:Message-ID:MIME-Version; b=YXaBAb0nMLBtvhVtCHbWrXIvBMEm9pOtgvAbQC8oyI81bGmIDjabrVz3iwaOsun+pvwVZAQwVLZ0SuxtZ0tbBU9oq7vWiArBam8wxcop3cBBL2+GFIRaJ2ISPqK9eB1uWJWgDuaDO9bs5i21MB213jbza9tx7cjmtVwXN2eDG/E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=rd8rhSDB; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=+aL339Hx; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=ulXori7d; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=C6epso+Y; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="rd8rhSDB"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="+aL339Hx"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="ulXori7d"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="C6epso+Y" Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id C94A086DA9; Tue, 25 Aug 2026 08:28:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1787646519; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=wjHAGcnK0ZvPQt1wsP5hmNeXmRi5ZYMQySdP6zzFJK8=; b=rd8rhSDBwt5GYy/DHPkhaqJm79KZ92Li22LMx2qo3sZwXK0fnuPguDBN9wRWEU4kO5ahJ9 sPs2Nd1PAdKrslBrXh+zkYwyyWdoyvE1jOx0h6d2VHah/KZN4G/bbwxkFIF5TYuZrn83zK Df1Pt9YRjZ6P9RT63AZb7Q4GboAkAyI= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1787646519; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=wjHAGcnK0ZvPQt1wsP5hmNeXmRi5ZYMQySdP6zzFJK8=; b=+aL339Hxay4PWUe8rkq2tFXKQqjNx9XVvdXvpDg3m4rl4YA5jPtmoOolgy15dd5LXzHKmx WexFh0zpJVT67KBQ== Authentication-Results: smtp-out1.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1787646515; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=wjHAGcnK0ZvPQt1wsP5hmNeXmRi5ZYMQySdP6zzFJK8=; b=ulXori7dfxB39jw9cGfRTE9G8RgLpRllBtyZ1EFLjHBmEoOQpCaL70nzGqFZaxrOO76PiE DXMCPv0/Xw8U5NTcN4655HY50QTcIOBzNpYrf/zr+HBm/mZqnhTIWtcgJ6tkJQHRGmAOEd QJsyHF4puWiin/K5qTxOLqWeaf7uc14= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1787646515; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=wjHAGcnK0ZvPQt1wsP5hmNeXmRi5ZYMQySdP6zzFJK8=; b=C6epso+YRz4+hOfoCX72FfOolGXyyDgOKfymW3jyLcN4K2xvhNCPGSZp4gail3VCKXNDeu CFKcuYHDsgGrJ1Bw== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id ABBA513331; Tue, 25 Aug 2026 08:28:35 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id 2+prKDNSjWphDgAAD6G6ig (envelope-from ); Tue, 25 Aug 2026 08:28:35 +0000 From: Takashi Iwai To: linux-sound@vger.kernel.org Subject: [PATCH] ALSA: rawmidi: Another workaround for false-positive mutex lockdep warning Date: Tue, 25 Aug 2026 10:28:33 +0200 Message-ID: <20260825082834.952365-1-tiwai@suse.de> X-Mailer: git-send-email 2.55.0 Precedence: bulk X-Mailing-List: linux-sound@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Score: -2.80 X-Spam-Level: X-Spam-Flag: NO X-Spamd-Result: default: False [-2.80 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_MISSING_CHARSET(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-0.999]; MIME_GOOD(-0.10)[text/plain]; ARC_NA(0.00)[]; RCPT_COUNT_ONE(0.00)[1]; RCVD_VIA_SMTP_AUTH(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; DBL_BLOCKED_OPENRESOLVER(0.00)[appspotmail.com:email,suse.de:email,suse.de:mid,imap1.dmz-prg2.suse.org:helo]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; MIME_TRACE(0.00)[0:+]; FROM_EQ_ENVFROM(0.00)[]; TO_DN_NONE(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; RCVD_TLS_ALL(0.00)[] While we attempted to work around the false-positive lockdep warning due to the nested mutex lock in rawmidi at the open path for a UMP legacy rawmidi, it didn't cover the similar locking at its close path, and this still caused another false-positive reports by syzkaller. Add a similar workaround to snd_rawmidi_kernel_release() as done in the former commit 9c04742e73b3 ("ALSA: rawmidi: Work around false-positive mutex lockdep warning") to cover completely. Reported-by: syzbot+7d1edf0ff6a05961020c@syzkaller.appspotmail.com Closes: https://lore.kernel.org/6a8c7e4d.4d75e56a.c9a88.0052.GAE@google.com Signed-off-by: Takashi Iwai --- include/sound/rawmidi.h | 8 +++++++- sound/core/rawmidi.c | 9 ++++++--- sound/core/ump.c | 3 ++- 3 files changed, 15 insertions(+), 5 deletions(-) diff --git a/include/sound/rawmidi.h b/include/sound/rawmidi.h index 88a6159364d0..4154035af414 100644 --- a/include/sound/rawmidi.h +++ b/include/sound/rawmidi.h @@ -179,7 +179,8 @@ int snd_rawmidi_info_select(struct snd_card *card, struct snd_rawmidi_info *info int snd_rawmidi_kernel_open_nested(struct snd_rawmidi *rmidi, int subdevice, int mode, struct snd_rawmidi_file *rfile, int depth); -int snd_rawmidi_kernel_release(struct snd_rawmidi_file *rfile); +int snd_rawmidi_kernel_release_nested(struct snd_rawmidi_file *rfile, + int depth); int snd_rawmidi_output_params(struct snd_rawmidi_substream *substream, struct snd_rawmidi_params *params); int snd_rawmidi_input_params(struct snd_rawmidi_substream *substream, @@ -201,6 +202,11 @@ static inline int snd_rawmidi_kernel_open(struct snd_rawmidi *rmidi, return snd_rawmidi_kernel_open_nested(rmidi, subdevice, mode, rfile, 0); } +static inline int snd_rawmidi_kernel_release(struct snd_rawmidi_file *rfile) +{ + return snd_rawmidi_kernel_release_nested(rfile, 0); +} + /* set up the tied devices */ static inline void snd_rawmidi_tie_devices(struct snd_rawmidi *r1, struct snd_rawmidi *r2) diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c index bf504e27f73e..b688fd76f5d5 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -571,7 +571,6 @@ static void rawmidi_release_priv(struct snd_rawmidi_file *rfile) struct snd_rawmidi *rmidi; rmidi = rfile->rmidi; - guard(mutex)(&rmidi->open_mutex); if (rfile->input) { close_substream(rmidi, rfile->input, 1); rfile->input = NULL; @@ -585,7 +584,8 @@ static void rawmidi_release_priv(struct snd_rawmidi_file *rfile) } /* called from sound/core/seq/seq_midi.c */ -int snd_rawmidi_kernel_release(struct snd_rawmidi_file *rfile) +int snd_rawmidi_kernel_release_nested(struct snd_rawmidi_file *rfile, + int depth) { struct snd_rawmidi *rmidi; @@ -593,7 +593,9 @@ int snd_rawmidi_kernel_release(struct snd_rawmidi_file *rfile) return -ENXIO; rmidi = rfile->rmidi; + mutex_lock_nested(&rmidi->open_mutex, depth); rawmidi_release_priv(rfile); + mutex_unlock(&rmidi->open_mutex); module_put(rmidi->card->module); return 0; } @@ -607,7 +609,8 @@ static int snd_rawmidi_release(struct inode *inode, struct file *file) rfile = file->private_data; rmidi = rfile->rmidi; - rawmidi_release_priv(rfile); + scoped_guard(mutex, &rmidi->open_mutex) + rawmidi_release_priv(rfile); kfree(rfile); module = rmidi->card->module; snd_card_file_remove(rmidi->card, file); diff --git a/sound/core/ump.c b/sound/core/ump.c index 82ad155c56e6..d183c8a000bd 100644 --- a/sound/core/ump.c +++ b/sound/core/ump.c @@ -1184,7 +1184,8 @@ static int snd_ump_legacy_close(struct snd_rawmidi_substream *substream) ump->legacy_substreams[dir][group] = NULL; if (dir == SNDRV_RAWMIDI_STREAM_OUTPUT) { if (!--ump->legacy_out_opens) - snd_rawmidi_kernel_release(&ump->legacy_out_rfile); + snd_rawmidi_kernel_release_nested(&ump->legacy_out_rfile, + SINGLE_DEPTH_NESTING); } return 0; } -- 2.55.0