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,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 5A8DEC43613 for ; Thu, 20 Jun 2019 18:27:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2CFC5206BF for ; Thu, 20 Jun 2019 18:27:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561055221; bh=UUtY7uaP00LJZzWSApNObWwt5epQ/e5gEjLUXTwcBwc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xWPzTfH3SS4qBoYJgJe/uLFdvbvduFC7uq/1DOt4ns8dssb0CLTLbcWQVXTVHINn7 79YEwqM3cVAAstw3FouHfnPn9DoLZDnWAiy1VtF/6uKvHSQwYkeIsQrAOMJ4UzVqz6 D3doxVD6rOGCUCAOZ0JaOUKJexRGKLsIpb0t/sE8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728043AbfFTSF1 (ORCPT ); Thu, 20 Jun 2019 14:05:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:58692 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728005AbfFTSFV (ORCPT ); Thu, 20 Jun 2019 14:05:21 -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 30350204FD; Thu, 20 Jun 2019 18:05:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1561053920; bh=UUtY7uaP00LJZzWSApNObWwt5epQ/e5gEjLUXTwcBwc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0malLA22iPJjxgNOPG9dcchiKU8SLOMzWSddi68ufAbYvSHcylNTNlGSILsCLwlTk kt0ZtQpHXolk1daTmunRx4NER/vyj/aXdmSacnwxN8TgMRYjSJndn9V3gI2hjxgzgQ Sg/vYPza9ro0IVyq6AoNfGPVXOtGzIpZN/wIeEsQ= 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 4.9 072/117] Revert "ALSA: seq: Protect in-kernel ioctl calls with mutex" Date: Thu, 20 Jun 2019 19:56:46 +0200 Message-Id: <20190620174356.933060710@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190620174351.964339809@linuxfoundation.org> References: <20190620174351.964339809@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 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