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=-8.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 104CFC31E5B for ; Mon, 17 Jun 2019 21:36:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8EE020657 for ; Mon, 17 Jun 2019 21:36:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560807370; bh=spFdKtBn734P0rF1qx0cgEPcZGvSaAAFlKMTfzB/c04=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eqvu5y7Ow/P0Q/810gukzjuPKbkiEM64rxVngKYPp47MmqE3t1osP2HLXmPy9tqO+ gG18QjzZR/3biu/LTAQHQSRTlonFP3xiHnF24poI+u1OmrgYFW/FAOI+vy7rjVk5C3 8gOcNwoPLbmFqEN55hSqgAU2g5gSQ/MNGyXdhmWs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729653AbfFQVgJ (ORCPT ); Mon, 17 Jun 2019 17:36:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:46656 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729462AbfFQVWF (ORCPT ); Mon, 17 Jun 2019 17:22:05 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id A2518208CB; Mon, 17 Jun 2019 21:22:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560806525; bh=spFdKtBn734P0rF1qx0cgEPcZGvSaAAFlKMTfzB/c04=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Jq/FYL3+rv4VfHQKi04BTe2gKWUQ7azsMaLUuClocCJyroZZr8Sco2v/R9b4Avmd+ jmuqoNBNW9r9GLVfxMgAXAhvF1wCt/a+eYvq2IaG/2xJYnlYZzIyBORyve2CORf6+o cN0HKZNT1YP2BWkjwzJZ5r5ehSVZvddUDxdfeTPQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+47ded6c0f23016cde310@syzkaller.appspotmail.com, Takashi Iwai , Sasha Levin Subject: [PATCH 5.1 045/115] Revert "ALSA: seq: Protect in-kernel ioctl calls with mutex" Date: Mon, 17 Jun 2019 23:09:05 +0200 Message-Id: <20190617210802.581623298@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190617210759.929316339@linuxfoundation.org> References: <20190617210759.929316339@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ 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 8599f2937ac1..c99e1b77a45b 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