From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-133288-1522172516-2-5540823258068163793 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, HEADER_FROM_DIFFERENT_DOMAINS 0.249, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, T_RP_MATCHES_RCVD -0.01, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='CN', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='UTF-8' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: stable-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=arctest; t=1522172515; b=s9H+jXAGoo3XeomnJ4Q5ndrXtNSR3d0xQzExct+jMMIcfWA gVlB6qsTiBEfIPYAN+Hgf4ewE3WtCrLUqzFdMLIxqXPO3phIIL+cw/gCHfb35pj4 jFq8VatL8M9uGM0ZskfmQ7r8HMrJttc9rVYZ6EF3KCjkQuN6T2rPmNM3TvProIvb Ue/ZCI75W4zUqJeqh3lVkDUnAkfbntLTdWo3qV57Oop12OlgWcdVX3UTYIXTC7bm epVCoIVGyA0FN3rdMBKZyx8mYFPBm96YjpiJV6OK7bLnu5GBlDMyqd1AVERChIcG 0YDWU6hFvZU+63cUQxdkF0vMyRdJr1EftWYkj3Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=from:to:cc:subject:date:message-id :in-reply-to:references:mime-version:content-type:sender :list-id; s=arctest; t=1522172515; bh=tiSASD9YwCKeGyAvcqIQjHQktu U89nhfC7EvnjpGIic=; b=SFK58okgm4tD6a0hoEgbS96fkQdrCai+0d2mgQk9dp IeczkDj7fNNf9+aocEnhi4dIGFcMYlS1IO98knUpNsXLOWrvvR/NIbnJ6CGOpbYA FwhUi+77m17MFVha6jpSMO4o78YFa4xIZPBgAXck9OdxThCmAAnDLCsMHxGgDkK0 QrdL7a6lHA4opirAGSjbsNIbiCVlHaUFij9zT96CvFUb8YTg+p+zM+YOZusLdQ9D 3c34/lTs1X/olEyKfiDemvlYJu3EFYgLijQf45oYzUsJGa3YvnTKy3YWROmhKGb3 ghtHT5nS/Y/u9B7GvUNhvUDJCO4ftpfzPIVriNUEg/KQ== ARC-Authentication-Results: i=1; mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx2.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=linuxfoundation.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=stable-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=fail; x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=linuxfoundation.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfE4D4Pp2q7DHzMWrUDTEPULpL/OnWuQ0bU1E5R5hZdJq1Ii0YwhP1GFhZsLc9N9oHaQn5wsmzEEMd7sR5UtWCOi214LWJ5xzQPmCknk2zmnbfZIgbl+w zeaINq5FqJCJrXmTDQFufTpUygzQoD5SRM8c+tKV0NAZogQRM/rPxNJjuHBWPNeWhrBjZAmtMWAdZY7NKP8Gf+Kscdx/vezts9EZmjkX7CWUfmOVms9C8h2E X-CM-Analysis: v=2.3 cv=E8HjW5Vl c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=IkcTkHD0fZMA:10 a=v2DPQv5-lfwA:10 a=VwQbUJbxAAAA:8 a=ag1SF4gXAAAA:8 a=n4yHPK1a9YeVPVKjqp4A:9 a=FmBzSsjMmyFZxvAZ:21 a=9-BFIvEqx44UeleB:21 a=QEXdDO2ut3YA:10 a=AjGcO6oz07-iQ99wixmX:22 a=Yupwre4RP9_Eg_Bd0iYG:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752427AbeC0Rlh (ORCPT ); Tue, 27 Mar 2018 13:41:37 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:44098 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754086AbeC0Qdy (ORCPT ); Tue, 27 Mar 2018 12:33:54 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Takashi Iwai Subject: [PATCH 4.14 011/101] ALSA: aloop: Fix access to not-yet-ready substream via cable Date: Tue, 27 Mar 2018 18:26:43 +0200 Message-Id: <20180327162750.693836162@linuxfoundation.org> X-Mailer: git-send-email 2.16.3 In-Reply-To: <20180327162749.993880276@linuxfoundation.org> References: <20180327162749.993880276@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org X-Mailing-List: stable@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Takashi Iwai commit 8e6b1a72a75bb5067ccb6b56d8ca4aa3a300a64e upstream. In loopback_open() and loopback_close(), we assign and release the substream object to the corresponding cable in a racy way. It's neither locked nor done in the right position. The open callback assigns the substream before its preparation finishes, hence the other side of the cable may pick it up, which may lead to the invalid memory access. This patch addresses these: move the assignment to the end of the open callback, and wrap with cable->lock for avoiding concurrent accesses. Cc: Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/drivers/aloop.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/sound/drivers/aloop.c +++ b/sound/drivers/aloop.c @@ -666,7 +666,9 @@ static void free_cable(struct snd_pcm_su return; if (cable->streams[!substream->stream]) { /* other stream is still alive */ + spin_lock_irq(&cable->lock); cable->streams[substream->stream] = NULL; + spin_unlock_irq(&cable->lock); } else { /* free the cable */ loopback->cables[substream->number][dev] = NULL; @@ -706,7 +708,6 @@ static int loopback_open(struct snd_pcm_ loopback->cables[substream->number][dev] = cable; } dpcm->cable = cable; - cable->streams[substream->stream] = dpcm; snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS); @@ -738,6 +739,11 @@ static int loopback_open(struct snd_pcm_ runtime->hw = loopback_pcm_hardware; else runtime->hw = cable->hw; + + spin_lock_irq(&cable->lock); + cable->streams[substream->stream] = dpcm; + spin_unlock_irq(&cable->lock); + unlock: if (err < 0) { free_cable(substream);