From patchwork Fri Feb 21 07:39:50 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 230810 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=-9.8 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=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 14641C35648 for ; Fri, 21 Feb 2020 08:29:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DFCF020679 for ; Fri, 21 Feb 2020 08:29:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582273788; bh=Kg5IVRnEpP2SMZz+UVMqxwQ0BK2QI7KyO+6LMZWsYPg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=nOhkNsOkPG8hEjws600WohcPj2/hJLyAKyP99txw4syqlO5HdXm54HmNEn1DcvBZj VsUwXlGfSGg/aFcuFYdQcKED4GUCcvXawcnYRwzKyVmRq9FtE2eUaUWsKE3e49U2kB mBfs3qI1VapEE7wrf3LfqthwJgmCdItPtRSTgCwM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733287AbgBUIRA (ORCPT ); Fri, 21 Feb 2020 03:17:00 -0500 Received: from mail.kernel.org ([198.145.29.99]:54232 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387599AbgBUIQ6 (ORCPT ); Fri, 21 Feb 2020 03:16:58 -0500 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 9651524682; Fri, 21 Feb 2020 08:16:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1582273018; bh=Kg5IVRnEpP2SMZz+UVMqxwQ0BK2QI7KyO+6LMZWsYPg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q2DdOPomZNiJOYs5W6UA6yfQT9qWWlG/e4K+VlnI49PhhY5k0OTAzq8PPL6vYf0Ju qeschWZgHi1eV/uirIEUj0QzPPdvkFJBpOM/R7zZEPubpCuEin693UFZFPv1vCovcr eIWF2iuFdrL+wFnK0gG5p/6DgbR6wo+zGnzEizhw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Takashi Sakamoto , Jaroslav Kysela , Takashi Iwai , Sasha Levin Subject: [PATCH 4.19 017/191] ALSA: ctl: allow TLV read operation for callback type of element in locked case Date: Fri, 21 Feb 2020 08:39:50 +0100 Message-Id: <20200221072253.251887423@linuxfoundation.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200221072250.732482588@linuxfoundation.org> References: <20200221072250.732482588@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Takashi Sakamoto [ Upstream commit d61fe22c2ae42d9fd76c34ef4224064cca4b04b0 ] A design of ALSA control core allows applications to execute three operations for TLV feature; read, write and command. Furthermore, it allows driver developers to process the operations by two ways; allocated array or callback function. In the former, read operation is just allowed, thus developers uses the latter when device driver supports variety of models or the target model is expected to dynamically change information stored in TLV container. The core also allows applications to lock any element so that the other applications can't perform write operation to the element for element value and TLV information. When the element is locked, write and command operation for TLV information are prohibited as well as element value. Any read operation should be allowed in the case. At present, when an element has callback function for TLV information, TLV read operation returns EPERM if the element is locked. On the other hand, the read operation is success when an element has allocated array for TLV information. In both cases, read operation is success for element value expectedly. This commit fixes the bug. This change can be backported to v4.14 kernel or later. Signed-off-by: Takashi Sakamoto Reviewed-by: Jaroslav Kysela Link: https://lore.kernel.org/r/20191223093347.15279-1-o-takashi@sakamocchi.jp Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/control.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/sound/core/control.c b/sound/core/control.c index 649d3217590ed..d1312f14d78fb 100644 --- a/sound/core/control.c +++ b/sound/core/control.c @@ -1468,8 +1468,9 @@ static int call_tlv_handler(struct snd_ctl_file *file, int op_flag, if (kctl->tlv.c == NULL) return -ENXIO; - /* When locked, this is unavailable. */ - if (vd->owner != NULL && vd->owner != file) + /* Write and command operations are not allowed for locked element. */ + if (op_flag != SNDRV_CTL_TLV_OP_READ && + vd->owner != NULL && vd->owner != file) return -EPERM; return kctl->tlv.c(kctl, op_flag, size, buf);