From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751513AbcBKOeN (ORCPT ); Thu, 11 Feb 2016 09:34:13 -0500 Received: from mx2.suse.de ([195.135.220.15]:49321 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753362AbcBKN7q (ORCPT ); Thu, 11 Feb 2016 08:59:46 -0500 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nicolas Boichat , Takashi Iwai , Jiri Slaby Subject: [PATCH 3.12 11/64] ALSA: pcm: Fix snd_pcm_hw_params struct copy in compat mode Date: Thu, 11 Feb 2016 14:58:47 +0100 Message-Id: <73c6819503642b1318343be17bf37bf4682669fe.1455198893.git.jslaby@suse.cz> X-Mailer: git-send-email 2.7.1 In-Reply-To: <74c0820133f1dada0d70c74bc70a9530b2697f86.1455198893.git.jslaby@suse.cz> References: <74c0820133f1dada0d70c74bc70a9530b2697f86.1455198893.git.jslaby@suse.cz> In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Nicolas Boichat 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit 43c54b8c7cfe22f868a751ba8a59abf1724160b1 upstream. This reverts one hunk of commit ef44a1ec6eee ("ALSA: sound/core: use memdup_user()"), which replaced a number of kmalloc followed by memcpy with memdup calls. In this case, we are copying from a struct snd_pcm_hw_params32 to a struct snd_pcm_hw_params, but the latter is 4 bytes longer than the 32-bit version, so we need to separate kmalloc and copy calls. This actually leads to an out-of-bounds memory access later on in sound/soc/soc-pcm.c:soc_pcm_hw_params() (detected using KASan). Fixes: ef44a1ec6eee ('ALSA: sound/core: use memdup_user()') Signed-off-by: Nicolas Boichat Signed-off-by: Takashi Iwai Signed-off-by: Jiri Slaby --- sound/core/pcm_compat.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/sound/core/pcm_compat.c b/sound/core/pcm_compat.c index c4ac3c1e19af..1bb1a43c7d03 100644 --- a/sound/core/pcm_compat.c +++ b/sound/core/pcm_compat.c @@ -236,10 +236,15 @@ static int snd_pcm_ioctl_hw_params_compat(struct snd_pcm_substream *substream, if (! (runtime = substream->runtime)) return -ENOTTY; - /* only fifo_size is different, so just copy all */ - data = memdup_user(data32, sizeof(*data32)); - if (IS_ERR(data)) - return PTR_ERR(data); + data = kmalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + /* only fifo_size (RO from userspace) is different, so just copy all */ + if (copy_from_user(data, data32, sizeof(*data32))) { + err = -EFAULT; + goto error; + } if (refine) err = snd_pcm_hw_refine(substream, data); -- 2.7.1