From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AD6E1C282CE for ; Tue, 4 Jun 2019 23:30:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7D4B0206B8 for ; Tue, 4 Jun 2019 23:30:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559691058; bh=yfyAS/804NSzHyG/cFvbagIkgGYlflnYNBfkE8Ow/MQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=UsnG14P12+geIKLNds7FQvzonWOFaOCowiq9TzzfX8I9cW6LN7MZNb5o1iIwWLOUx 4cc2EpDXLg1udquW72sJrHgOOte5Fxd1tyGVC7+evvFU4yJT7GQ7GuHweQSOo+q/S/ D2+fXQwFw9rXKcSYaeg6vpNHHs9WXigCbJtDjQm8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726809AbfFDXaw (ORCPT ); Tue, 4 Jun 2019 19:30:52 -0400 Received: from mail.kernel.org ([198.145.29.99]:34344 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727336AbfFDXXo (ORCPT ); Tue, 4 Jun 2019 19:23:44 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DD40620859; Tue, 4 Jun 2019 23:23:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559690623; bh=yfyAS/804NSzHyG/cFvbagIkgGYlflnYNBfkE8Ow/MQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tVfpB0T4uIfXfLTuO0SZw12ODvWkk4U1SbSOd/VBOEpov7VkJjaNny5uIpU4R0DH3 LqeymtRL+Gp/oe+bO58CKYQ53S1ulhke+Oq08rWNUcAFmWcLgMtxBvPN2w2eQvyKu5 m0LxRmd6keKE82+Vb1AYA4u1MjHusnYm0834uvC0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Takashi Iwai , syzbot+47ded6c0f23016cde310@syzkaller.appspotmail.com, Sasha Levin Subject: [PATCH AUTOSEL 4.19 04/36] Revert "ALSA: seq: Protect in-kernel ioctl calls with mutex" Date: Tue, 4 Jun 2019 19:22:59 -0400 Message-Id: <20190604232333.7185-4-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190604232333.7185-1-sashal@kernel.org> References: <20190604232333.7185-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Takashi Iwai [ Upstream commit f0654ba94e33699b295ce4f3dc73094db6209035 ] This reverts commit feb689025fbb6f0aa6297d3ddf97de945ea4ad32. The fix attempt was incorrect, leading to the mutex deadlock through the close of OSS sequencer client. The proper fix needs more consideration, so let's revert it now. Fixes: feb689025fbb ("ALSA: seq: Protect in-kernel ioctl calls with mutex") Reported-by: syzbot+47ded6c0f23016cde310@syzkaller.appspotmail.com Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/seq/seq_clientmgr.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c index 37312a3ae60f..f59e13c1d84a 100644 --- a/sound/core/seq/seq_clientmgr.c +++ b/sound/core/seq/seq_clientmgr.c @@ -2337,19 +2337,14 @@ int snd_seq_kernel_client_ctl(int clientid, unsigned int cmd, void *arg) { const struct ioctl_handler *handler; struct snd_seq_client *client; - int err; client = clientptr(clientid); if (client == NULL) return -ENXIO; for (handler = ioctl_handlers; handler->cmd > 0; ++handler) { - if (handler->cmd == cmd) { - mutex_lock(&client->ioctl_mutex); - err = handler->func(client, arg); - mutex_unlock(&client->ioctl_mutex); - return err; - } + if (handler->cmd == cmd) + return handler->func(client, arg); } pr_debug("ALSA: seq unknown ioctl() 0x%x (type='%c', number=0x%02x)\n", -- 2.20.1