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,URIBL_BLOCKED,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 9A2CBC433E1 for ; Mon, 29 Jun 2020 20:02:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7802220675 for ; Mon, 29 Jun 2020 20:02:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593460965; bh=WoMenmfxr0IjvI++MViBwkktvtiXVMqJDzJXgbCPS6k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=KcGUzM2aHBKJsX7r3J/Dg8lb6c2wpIJ+zdOebsLFPgvnPm+IohS3A3K+gYo2k1OJ2 KXhQL1eweFLwhLmZiDrDXN1f+hysd1864rW62o2o/fjSxWwVCGJxlTL6gj9m+gCCAs IHXvCsbnlVqYUvj6HUlswsDC4r+/ssFQNbdDMXGM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387590AbgF2UCo (ORCPT ); Mon, 29 Jun 2020 16:02:44 -0400 Received: from mail.kernel.org ([198.145.29.99]:40562 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732997AbgF2Tad (ORCPT ); Mon, 29 Jun 2020 15:30:33 -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 A7DA825239; Mon, 29 Jun 2020 15:35:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593444953; bh=WoMenmfxr0IjvI++MViBwkktvtiXVMqJDzJXgbCPS6k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=laZUBLxfBCLnOhsNH1Ggv2ZKup7loxkbLFQ5jJjTEgkNp8RAZcVZGY4QCtsHATZXn C17ewuKj6ZxdWhrV8Jds/qEnmLqL5W110AXlX4KDUvFTjgR4N8OJK4+JYOgV2syutc +YORMsos2A0WUluTaPDlEjPwBBsNADGvtCfxVd7c= 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, Greg Kroah-Hartman Subject: [PATCH 4.19 051/131] ALSA: usb-audio: Fix OOB access of mixer element list Date: Mon, 29 Jun 2020 11:33:42 -0400 Message-Id: <20200629153502.2494656-52-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200629153502.2494656-1-sashal@kernel.org> References: <20200629153502.2494656-1-sashal@kernel.org> MIME-Version: 1.0 X-KernelTest-Patch: http://kernel.org/pub/linux/kernel/v4.x/stable-review/patch-4.19.131-rc1.gz X-KernelTest-Tree: git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git X-KernelTest-Branch: linux-4.19.y X-KernelTest-Patches: git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git X-KernelTest-Version: 4.19.131-rc1 X-KernelTest-Deadline: 2020-07-01T15:34+00:00 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Takashi Iwai commit 220345e98f1cdc768eeb6e3364a0fa7ab9647fe7 upstream. 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: Greg Kroah-Hartman --- 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 8a0211131fc6f..45bd3d54be54b 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -591,8 +591,9 @@ 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; @@ -606,6 +607,7 @@ 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; @@ -3232,8 +3234,11 @@ void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid) unitid = delegate_notify(mixer, unitid, NULL, NULL); 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, @@ -3313,6 +3318,8 @@ 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 15ec90e96d4d9..f7e6fe1a96f9c 100644 --- a/sound/usb/mixer.h +++ b/sound/usb/mixer.h @@ -59,6 +59,7 @@ 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; }; @@ -96,8 +97,12 @@ 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 983e8a3ebfcfe..21c1135bb89b4 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