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 C9439C433E0 for ; Mon, 29 Jun 2020 18:56:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AF6AC20663 for ; Mon, 29 Jun 2020 18:56:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593456993; bh=HMYTN0rthApnSgRbc8HR0EZ95JaKoA184P4oglDPkFQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=vo04MrB/RIu5DWTJ0N4WFTSYIVC5BGt2R0Bi6YFPIdEhHkAUi+Ha00485q/nDof/I iCqjFziAK5YdvsaVfXytewEL38EWIejVl7jOSLKjdEQSWsR47jwqW3HPrRiLSwGmoh 9pHuLn6fJaN/+yewKrQIxE7TnKlxr5wcvsDE7YaE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730048AbgF2S4b (ORCPT ); Mon, 29 Jun 2020 14:56:31 -0400 Received: from mail.kernel.org ([198.145.29.99]:42446 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729966AbgF2SzR (ORCPT ); Mon, 29 Jun 2020 14:55:17 -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 8904820720; Mon, 29 Jun 2020 15:55:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593446116; bh=HMYTN0rthApnSgRbc8HR0EZ95JaKoA184P4oglDPkFQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Iob4gZU9ZJ+jq5NReZuBrtVRgV2EzcLkY2+sGR2ZWFCGlOAr1HCx5FoGjhd3T36In DZDrBJsgu3IINzwRjHhc1+A6UHvVL8XDF7EieZn5IsEgKLdMhc99kQuh0yChJzboql R1b7MHANJd+HU6IyOQLN2ewJ7W1iFKGgj9cOLKek= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Takashi Iwai , syzbot+fb14314433463ad51625@syzkaller.appspotmail.com, syzbot+2405ca3401e943c538b5@syzkaller.appspotmail.com, Sasha Levin Subject: [PATCH 4.4 107/135] ALSA: usb-audio: Fix OOB access of mixer element list Date: Mon, 29 Jun 2020 11:52:41 -0400 Message-Id: <20200629155309.2495516-108-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200629155309.2495516-1-sashal@kernel.org> References: <20200629155309.2495516-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.4.229-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.4.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.4.229-rc1 X-KernelTest-Deadline: 2020-07-01T15:53+00:00 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 220345e98f1cdc768eeb6e3364a0fa7ab9647fe7 ] The USB-audio mixer code holds a linked list of usb_mixer_elem_list, and several operations are performed for each mixer element. A few of them (snd_usb_mixer_notify_id() and snd_usb_mixer_interrupt_v2()) assume each mixer element being a usb_mixer_elem_info object that is a subclass of usb_mixer_elem_list, cast via container_of() and access it members. This may result in an out-of-bound access when a non-standard list element has been added, as spotted by syzkaller recently. This patch adds a new field, is_std_info, in usb_mixer_elem_list to indicate that the element is the usb_mixer_elem_info type or not, and skip the access to such an element if needed. Reported-by: syzbot+fb14314433463ad51625@syzkaller.appspotmail.com Reported-by: syzbot+2405ca3401e943c538b5@syzkaller.appspotmail.com Cc: Link: https://lore.kernel.org/r/20200624122340.9615-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/usb/mixer.c | 15 +++++++++++---- sound/usb/mixer.h | 9 +++++++-- sound/usb/mixer_quirks.c | 3 ++- 3 files changed, 20 insertions(+), 7 deletions(-) diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index c29931cd461fc..9b9d653d5e90b 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -584,8 +584,9 @@ static int check_matrix_bitmap(unsigned char *bmap, * if failed, give up and free the control instance. */ -int snd_usb_mixer_add_control(struct usb_mixer_elem_list *list, - struct snd_kcontrol *kctl) +int snd_usb_mixer_add_list(struct usb_mixer_elem_list *list, + struct snd_kcontrol *kctl, + bool is_std_info) { struct usb_mixer_interface *mixer = list->mixer; int err; @@ -598,6 +599,7 @@ int snd_usb_mixer_add_control(struct usb_mixer_elem_list *list, return err; } list->kctl = kctl; + list->is_std_info = is_std_info; list->next_id_elem = mixer->id_elems[list->id]; mixer->id_elems[list->id] = list; return 0; @@ -2331,8 +2333,11 @@ void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid) struct usb_mixer_elem_list *list; for_each_mixer_elem(list, mixer, unitid) { - struct usb_mixer_elem_info *info = - mixer_elem_list_to_info(list); + struct usb_mixer_elem_info *info; + + if (!list->is_std_info) + continue; + info = mixer_elem_list_to_info(list); /* invalidate cache, so the value is read from the device */ info->cached = 0; snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE, @@ -2410,6 +2415,8 @@ static void snd_usb_mixer_interrupt_v2(struct usb_mixer_interface *mixer, if (!list->kctl) continue; + if (!list->is_std_info) + continue; info = mixer_elem_list_to_info(list); if (count > 1 && info->control != control) diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h index 004d99037210f..7d16a92210705 100644 --- a/sound/usb/mixer.h +++ b/sound/usb/mixer.h @@ -48,6 +48,7 @@ struct usb_mixer_elem_list { struct usb_mixer_elem_list *next_id_elem; /* list of controls with same id */ struct snd_kcontrol *kctl; unsigned int id; + bool is_std_info; usb_mixer_elem_dump_func_t dump; usb_mixer_elem_resume_func_t resume; }; @@ -85,8 +86,12 @@ void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid); int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval, int request, int validx, int value_set); -int snd_usb_mixer_add_control(struct usb_mixer_elem_list *list, - struct snd_kcontrol *kctl); +int snd_usb_mixer_add_list(struct usb_mixer_elem_list *list, + struct snd_kcontrol *kctl, + bool is_std_info); + +#define snd_usb_mixer_add_control(list, kctl) \ + snd_usb_mixer_add_list(list, kctl, true) void snd_usb_mixer_elem_init_std(struct usb_mixer_elem_list *list, struct usb_mixer_interface *mixer, diff --git a/sound/usb/mixer_quirks.c b/sound/usb/mixer_quirks.c index 5d6af9c861ad9..198515f86fcc2 100644 --- a/sound/usb/mixer_quirks.c +++ b/sound/usb/mixer_quirks.c @@ -168,7 +168,8 @@ static int add_single_ctl_with_resume(struct usb_mixer_interface *mixer, return -ENOMEM; } kctl->private_free = snd_usb_mixer_elem_free; - return snd_usb_mixer_add_control(list, kctl); + /* don't use snd_usb_mixer_add_control() here, this is a special list element */ + return snd_usb_mixer_add_list(list, kctl, false); } /* -- 2.25.1