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=unavailable 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 22D30C31E5B for ; Mon, 17 Jun 2019 21:30:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E7550204FD for ; Mon, 17 Jun 2019 21:30:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560807053; bh=59veLdSvEe9BEys5yRYaEXKgybkj5rzWLSkW2eYQ+4I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Dd70ZCc0FB2BSgq44MtATK447rKSWcEgVj5nOyU8dGy3QxRu/ujgyptXZHIeX4jtu E1FnvA72HMOWxIQAFKATDAGILM122++Lkrwo9EBRxuCuZaOCMIr9lcaSqL5jUhmn9g Zlwrht0Z0JFp3WJwHJ85Gxx3xlGgvbhL/zmzMHEw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730279AbfFQV3y (ORCPT ); Mon, 17 Jun 2019 17:29:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:57074 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730296AbfFQV3x (ORCPT ); Mon, 17 Jun 2019 17:29:53 -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 56CE521734; Mon, 17 Jun 2019 21:29:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560806992; bh=59veLdSvEe9BEys5yRYaEXKgybkj5rzWLSkW2eYQ+4I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sGbTDEqYNSfMAdgi/D/8uVua4G5+fcveFPWO7SibrrWnfh6ADByxeKbgNf8lADNWR dkH4sN7dbj0SqzKJlgy32ZZfuitgrkQsXPrHEPe+Ns1I8EwHnnVGLzn4gRRB3LD8t8 w1R+YbALwi3UpmbqT075uFdlYtrusGoOxszWp1R4= 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 4.14 25/53] Revert "ALSA: seq: Protect in-kernel ioctl calls with mutex" Date: Mon, 17 Jun 2019 23:10:08 +0200 Message-Id: <20190617210750.276520329@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190617210745.104187490@linuxfoundation.org> References: <20190617210745.104187490@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 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