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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 0C9AFC43331 for ; Wed, 30 Dec 2020 13:07:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C88CB2220B for ; Wed, 30 Dec 2020 13:07:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727888AbgL3NHf (ORCPT ); Wed, 30 Dec 2020 08:07:35 -0500 Received: from mail.kernel.org ([198.145.29.99]:53386 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727449AbgL3NF2 (ORCPT ); Wed, 30 Dec 2020 08:05:28 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id D71B1229EF; Wed, 30 Dec 2020 13:04:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1609333474; bh=lAXHsb70nJP+WYyBcH4Sr0dYyef1OZUZJDEgRu/5+Wg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MT/Mg4JGG1hPSHbCbsP1k5QWOjxRowd68evOaAKrTQilr8fPT2poXfw/v9j64wfiv Ki/uzT4tYW8B4OxTtGCdxhQZZ9qYIgTpU9LmTb7QobcdRkngiAoI+Z3n0ej3bQI9NQ w1bW00PqNoiixIuyTqTz6yUUfD7R4zR2zPRJQ9Qn0osfy4noIPTdNZ4Pjrmm2I6x0x fgWTvLMM+9WMrQl8rsu/xOw+Zkv+E99K6hRkLNDHHmOMtHY0SHuGVm0hm3PdqHULs8 E7d8GshT7LpAwPUX5XiWIrEalh9HNttrzYSgsNGVwX5ZeR4phmbqaAnb53vDE7o4Rt YdfaUGf8KuRyg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Takashi Iwai , Lars-Peter Clausen , Sasha Levin , alsa-devel@alsa-project.org Subject: [PATCH AUTOSEL 4.19 09/10] ALSA: pcm: Clear the full allocated memory at hw_params Date: Wed, 30 Dec 2020 08:04:21 -0500 Message-Id: <20201230130422.3637448-9-sashal@kernel.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20201230130422.3637448-1-sashal@kernel.org> References: <20201230130422.3637448-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Takashi Iwai [ Upstream commit 618de0f4ef11acd8cf26902e65493d46cc20cc89 ] The PCM hw_params core function tries to clear up the PCM buffer before actually using for avoiding the information leak from the previous usages or the usage before a new allocation. It performs the memset() with runtime->dma_bytes, but this might still leave some remaining bytes untouched; namely, the PCM buffer size is aligned in page size for mmap, hence runtime->dma_bytes doesn't necessarily cover all PCM buffer pages, and the remaining bytes are exposed via mmap. This patch changes the memory clearance to cover the all buffer pages if the stream is supposed to be mmap-ready (that guarantees that the buffer size is aligned in page size). Reviewed-by: Lars-Peter Clausen Link: https://lore.kernel.org/r/20201218145625.2045-3-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/pcm_native.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index 7c12b0deb4eb5..db62dbe7eaa8a 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -753,8 +753,13 @@ static int snd_pcm_hw_params(struct snd_pcm_substream *substream, runtime->boundary *= 2; /* clear the buffer for avoiding possible kernel info leaks */ - if (runtime->dma_area && !substream->ops->copy_user) - memset(runtime->dma_area, 0, runtime->dma_bytes); + if (runtime->dma_area && !substream->ops->copy_user) { + size_t size = runtime->dma_bytes; + + if (runtime->info & SNDRV_PCM_INFO_MMAP) + size = PAGE_ALIGN(size); + memset(runtime->dma_area, 0, size); + } snd_pcm_timer_resolution_change(substream); snd_pcm_set_state(substream, SNDRV_PCM_STATE_SETUP); -- 2.27.0