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 11872C31E5B for ; Mon, 17 Jun 2019 21:27:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D68BE206B7 for ; Mon, 17 Jun 2019 21:27:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560806840; bh=KJ+YJKyC3zl5fWNmO53Na+GxPfZc8sgKoRsOHBTjoss=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Cx9fuo/LqZzgRoZDP8xBRRbRfx8tFE4JmQEmr8rjC5CG8eKbPPo+G7a9y4WPs2QH8 XBmi7CZkNYCPah95/glgMCxGm8YMw1PWOiu0G2LVaVD7r7fIe+iUDg5T8/8fAFab6T dkAGm3i/BBBHPpM9xCdDbmxERJ6hs8cFSB6CZr30= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730379AbfFQV1T (ORCPT ); Mon, 17 Jun 2019 17:27:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:54198 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730374AbfFQV1R (ORCPT ); Mon, 17 Jun 2019 17:27:17 -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 0AE852063F; Mon, 17 Jun 2019 21:27:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560806836; bh=KJ+YJKyC3zl5fWNmO53Na+GxPfZc8sgKoRsOHBTjoss=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Zsm3VYqmqPfkdNKcjKzZfaB6YUjI6oKJtEGS5joReZBcyVHSJwcwM9Gh7ee8IdX5S wTbIMYZjvBeEBdp1lzja7fLO++M9NNghBP4YcebaSzzBhv4NByfl7jbYsBJOeCOibP 3wQ5LIyc2OujKEFirieu911QaiBN2mhrNN3uN9Ks= 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 4.19 30/75] Revert "ALSA: seq: Protect in-kernel ioctl calls with mutex" Date: Mon, 17 Jun 2019 23:09:41 +0200 Message-Id: <20190617210753.982269979@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190617210752.799453599@linuxfoundation.org> References: <20190617210752.799453599@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 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