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=-10.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, 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 13A65C43331 for ; Thu, 26 Mar 2020 23:35:54 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8FFA2206F8 for ; Thu, 26 Mar 2020 23:35:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="B1GoWsi8"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="R/4FECVG" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8FFA2206F8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id CCCD21668; Fri, 27 Mar 2020 00:35:01 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz CCCD21668 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1585265751; bh=DMDAmsX01Z1tF2K9W75nHKqQQTSG6LCtx+m5EJLBaZ4=; h=From:To:Subject:Date:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=B1GoWsi84gi3Z3d7AM8u/c1q9Wo2xI6CNf7iuDxJSBJYbMWN7C5yAu+JL96m6lWfl dYj/MbZCFG/U9/mtTwieGvPocC6FoN11qrkHSMVR4TB6niUuHwVhwBBM325e94bTYe TypB+Qd8VynH7A12Y5jIcEpA+WfI2gkKoFeasB8c= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id EF885F8033E; Fri, 27 Mar 2020 00:25:40 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 13E29F80339; Fri, 27 Mar 2020 00:25:37 +0100 (CET) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 26291F80339 for ; Fri, 27 Mar 2020 00:25:34 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 26291F80339 Authentication-Results: alsa1.perex.cz; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="R/4FECVG" 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 F251D208E0; Thu, 26 Mar 2020 23:25:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585265132; bh=DMDAmsX01Z1tF2K9W75nHKqQQTSG6LCtx+m5EJLBaZ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R/4FECVGGKqCnyhX6SmrKvOfaJnJ3xlcYd3A++Drdr7wBYZ3vyAHcpc4MT7t9/nA1 7ADg+HALouubT/CZYdE0xKnF7dcaAT17GMz/yjOl9YNNlHmahI3ftE6+hoG3JC/1XZ wrcHdk8FXM9pt9fvXUa0q5SFUupTy+9RH4R5HdoM= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 4.9 5/7] ALSA: pcm: oss: Avoid plugin buffer overflow Date: Thu, 26 Mar 2020 19:25:24 -0400 Message-Id: <20200326232526.8349-5-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200326232526.8349-1-sashal@kernel.org> References: <20200326232526.8349-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Cc: Takashi Iwai , Sasha Levin , syzbot+e1fe9f44fb8ecf4fb5dd@syzkaller.appspotmail.com, alsa-devel@alsa-project.org X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" From: Takashi Iwai [ Upstream commit f2ecf903ef06eb1bbbfa969db9889643d487e73a ] Each OSS PCM plugins allocate its internal buffer per pre-calculation of the max buffer size through the chain of plugins (calling src_frames and dst_frames callbacks). This works for most plugins, but the rate plugin might behave incorrectly. The calculation in the rate plugin involves with the fractional position, i.e. it may vary depending on the input position. Since the buffer size pre-calculation is always done with the offset zero, it may return a shorter size than it might be; this may result in the out-of-bound access as spotted by fuzzer. This patch addresses those possible buffer overflow accesses by simply setting the upper limit per the given buffer size for each plugin before src_frames() and after dst_frames() calls. Reported-by: syzbot+e1fe9f44fb8ecf4fb5dd@syzkaller.appspotmail.com Cc: Link: https://lore.kernel.org/r/000000000000b25ea005a02bcf21@google.com Link: https://lore.kernel.org/r/20200309082148.19855-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/oss/pcm_plugin.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/sound/core/oss/pcm_plugin.c b/sound/core/oss/pcm_plugin.c index c6888d76ca5e9..b08b2d2d804bd 100644 --- a/sound/core/oss/pcm_plugin.c +++ b/sound/core/oss/pcm_plugin.c @@ -209,6 +209,8 @@ snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *plug, snd_p if (stream == SNDRV_PCM_STREAM_PLAYBACK) { plugin = snd_pcm_plug_last(plug); while (plugin && drv_frames > 0) { + if (drv_frames > plugin->buf_frames) + drv_frames = plugin->buf_frames; plugin_prev = plugin->prev; if (plugin->src_frames) drv_frames = plugin->src_frames(plugin, drv_frames); @@ -220,6 +222,8 @@ snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *plug, snd_p plugin_next = plugin->next; if (plugin->dst_frames) drv_frames = plugin->dst_frames(plugin, drv_frames); + if (drv_frames > plugin->buf_frames) + drv_frames = plugin->buf_frames; plugin = plugin_next; } } else @@ -248,11 +252,15 @@ snd_pcm_sframes_t snd_pcm_plug_slave_size(struct snd_pcm_substream *plug, snd_pc if (frames < 0) return frames; } + if (frames > plugin->buf_frames) + frames = plugin->buf_frames; plugin = plugin_next; } } else if (stream == SNDRV_PCM_STREAM_CAPTURE) { plugin = snd_pcm_plug_last(plug); while (plugin) { + if (frames > plugin->buf_frames) + frames = plugin->buf_frames; plugin_prev = plugin->prev; if (plugin->src_frames) { frames = plugin->src_frames(plugin, frames); -- 2.20.1 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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 2073EC2D0E8 for ; Thu, 26 Mar 2020 23:26:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E9F6220409 for ; Thu, 26 Mar 2020 23:26:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585265165; bh=DMDAmsX01Z1tF2K9W75nHKqQQTSG6LCtx+m5EJLBaZ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=SsaGPC7g66nreuF1O+Ix6qdzyoU97gvaAjUq53Sv8JaHQ58tSJu1xhb5MI2AvIbAP r0xAeTF/fnAYb9dbXquDd58DO93f+9jYM+4A+lnQeoKYw1b6ozpQ6os/H0ZPg1nfu/ D8XIWwmInMceKn54FBgspHq+cnpD0uSIJ7Jkaitk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728464AbgCZX0E (ORCPT ); Thu, 26 Mar 2020 19:26:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:46556 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728300AbgCZXZd (ORCPT ); Thu, 26 Mar 2020 19:25:33 -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 F251D208E0; Thu, 26 Mar 2020 23:25:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585265132; bh=DMDAmsX01Z1tF2K9W75nHKqQQTSG6LCtx+m5EJLBaZ4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R/4FECVGGKqCnyhX6SmrKvOfaJnJ3xlcYd3A++Drdr7wBYZ3vyAHcpc4MT7t9/nA1 7ADg+HALouubT/CZYdE0xKnF7dcaAT17GMz/yjOl9YNNlHmahI3ftE6+hoG3JC/1XZ wrcHdk8FXM9pt9fvXUa0q5SFUupTy+9RH4R5HdoM= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Takashi Iwai , syzbot+e1fe9f44fb8ecf4fb5dd@syzkaller.appspotmail.com, Sasha Levin , alsa-devel@alsa-project.org Subject: [PATCH AUTOSEL 4.9 5/7] ALSA: pcm: oss: Avoid plugin buffer overflow Date: Thu, 26 Mar 2020 19:25:24 -0400 Message-Id: <20200326232526.8349-5-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200326232526.8349-1-sashal@kernel.org> References: <20200326232526.8349-1-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 f2ecf903ef06eb1bbbfa969db9889643d487e73a ] Each OSS PCM plugins allocate its internal buffer per pre-calculation of the max buffer size through the chain of plugins (calling src_frames and dst_frames callbacks). This works for most plugins, but the rate plugin might behave incorrectly. The calculation in the rate plugin involves with the fractional position, i.e. it may vary depending on the input position. Since the buffer size pre-calculation is always done with the offset zero, it may return a shorter size than it might be; this may result in the out-of-bound access as spotted by fuzzer. This patch addresses those possible buffer overflow accesses by simply setting the upper limit per the given buffer size for each plugin before src_frames() and after dst_frames() calls. Reported-by: syzbot+e1fe9f44fb8ecf4fb5dd@syzkaller.appspotmail.com Cc: Link: https://lore.kernel.org/r/000000000000b25ea005a02bcf21@google.com Link: https://lore.kernel.org/r/20200309082148.19855-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/oss/pcm_plugin.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/sound/core/oss/pcm_plugin.c b/sound/core/oss/pcm_plugin.c index c6888d76ca5e9..b08b2d2d804bd 100644 --- a/sound/core/oss/pcm_plugin.c +++ b/sound/core/oss/pcm_plugin.c @@ -209,6 +209,8 @@ snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *plug, snd_p if (stream == SNDRV_PCM_STREAM_PLAYBACK) { plugin = snd_pcm_plug_last(plug); while (plugin && drv_frames > 0) { + if (drv_frames > plugin->buf_frames) + drv_frames = plugin->buf_frames; plugin_prev = plugin->prev; if (plugin->src_frames) drv_frames = plugin->src_frames(plugin, drv_frames); @@ -220,6 +222,8 @@ snd_pcm_sframes_t snd_pcm_plug_client_size(struct snd_pcm_substream *plug, snd_p plugin_next = plugin->next; if (plugin->dst_frames) drv_frames = plugin->dst_frames(plugin, drv_frames); + if (drv_frames > plugin->buf_frames) + drv_frames = plugin->buf_frames; plugin = plugin_next; } } else @@ -248,11 +252,15 @@ snd_pcm_sframes_t snd_pcm_plug_slave_size(struct snd_pcm_substream *plug, snd_pc if (frames < 0) return frames; } + if (frames > plugin->buf_frames) + frames = plugin->buf_frames; plugin = plugin_next; } } else if (stream == SNDRV_PCM_STREAM_CAPTURE) { plugin = snd_pcm_plug_last(plug); while (plugin) { + if (frames > plugin->buf_frames) + frames = plugin->buf_frames; plugin_prev = plugin->prev; if (plugin->src_frames) { frames = plugin->src_frames(plugin, frames); -- 2.20.1