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 E07FEC282CE for ; Tue, 4 Jun 2019 23:24:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B095320863 for ; Tue, 4 Jun 2019 23:24:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559690675; bh=qSJtONssb2dXmC2zEM/bd1LwV7WzJgwEOxApzS/gU38=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=gdaEDFqFptXI0fGSSNHEbEN/P0+Pfe2iRRhE9Scb9V4s9Sy1nFrIpdJI+a//D2s1A SRdsOzKVyQRNpHdd4EljLivLzc+jMmdXMWH7KZ2ymj7dqRP23+fNt1RgkksXAML0/W tvcPFLZS3LAnAhhymautcGhYVt+bJa5DD7behxZg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727626AbfFDXYe (ORCPT ); Tue, 4 Jun 2019 19:24:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:35494 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726988AbfFDXY2 (ORCPT ); Tue, 4 Jun 2019 19:24:28 -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 376B3208CB; Tue, 4 Jun 2019 23:24:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1559690667; bh=qSJtONssb2dXmC2zEM/bd1LwV7WzJgwEOxApzS/gU38=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2hGs0m/R5vBtD58HIGa4srrQ/yRp3eemypF07CF0Ra8CZCZZtTrBa7Vy1fjc3IuT0 FVv09tuWLGoztWiGnhiDVat1WKJeI6Myzzuz0qogco5M1sMK5RQaamt8VbMwwOfT2k c6Fsl60vhXiB0SNnGEq/f8xsGBO1qA6f9Bcbd+8Y= 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 4.14 04/24] Revert "ALSA: seq: Protect in-kernel ioctl calls with mutex" Date: Tue, 4 Jun 2019 19:23:55 -0400 Message-Id: <20190604232416.7479-4-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190604232416.7479-1-sashal@kernel.org> References: <20190604232416.7479-1-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 068880ac47b5..7d2c07c1237c 100644 --- a/sound/core/seq/seq_clientmgr.c +++ b/sound/core/seq/seq_clientmgr.c @@ -2342,19 +2342,14 @@ 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