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=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 71934C282CE for ; Tue, 4 Jun 2019 23:27:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3885D206B8 for ; Tue, 4 Jun 2019 23:27:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559690848; bh=BH2DFu3+7KehxzHLPAsAJYDzpvVppzmYsL8rKbaOXfY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uIH1NQkZEDI14jzyhIzSLvFQcT48gkTPgdrTErTwTefAFg31QBBdk9hWm88jWOE5Q YqfrDHjHsRoc/oOEX1RHLFc7A6+yWs83FKQSAKlo+cEiX3/mYf/3w9H5Fw6HJUpnXQ 0YR8lgl2bLva4ZyeitqPIeJlSbECrgjH6xCuf8Aw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727915AbfFDXZP (ORCPT ); Tue, 4 Jun 2019 19:25:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:36670 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727875AbfFDXZK (ORCPT ); Tue, 4 Jun 2019 19:25:10 -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 70F2820862; Tue, 4 Jun 2019 23:25:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559690710; bh=BH2DFu3+7KehxzHLPAsAJYDzpvVppzmYsL8rKbaOXfY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I5Y7KKJZfmTcevZAUO8OsOG5ga4CeDyMHiD6iXuy0pqbH5XrLA/fR0hE9FmlwAncl v3yXynCggD10p4yrkco96MhNBEbQ4qrnG9kousV5C4RIeNMm384IkFxPQDAwLTcpJy IPa9WRTRJRGF5x5MqANcx3RcknzsfbKg87dqidDw= 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 4.9 04/17] Revert "ALSA: seq: Protect in-kernel ioctl calls with mutex" Date: Tue, 4 Jun 2019 19:24:45 -0400 Message-Id: <20190604232459.7745-4-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190604232459.7745-1-sashal@kernel.org> References: <20190604232459.7745-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 881c965555c5..bc6d371031fc 100644 --- a/sound/core/seq/seq_clientmgr.c +++ b/sound/core/seq/seq_clientmgr.c @@ -2348,19 +2348,14 @@ 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