From nobody Mon Jun 29 12:37:01 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D74F4C433F5 for ; Wed, 9 Feb 2022 19:15:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232688AbiBITPH (ORCPT ); Wed, 9 Feb 2022 14:15:07 -0500 Received: from gmail-smtp-in.l.google.com ([23.128.96.19]:40100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232298AbiBITPD (ORCPT ); Wed, 9 Feb 2022 14:15:03 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EA6BAC0086EA; Wed, 9 Feb 2022 11:14:55 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C144C61921; Wed, 9 Feb 2022 19:14:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9EB5AC340E7; Wed, 9 Feb 2022 19:14:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1644434089; bh=t5k1chf6+v5HfwvAbZWz1wYKfDCyFxon6T1Ca+KqJUM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aFbai6LqRQ8srZp+gK3iEPk57GtPiSiLANXxwCm2tdcPdvr+SulJblCi3rSQeN7ZQ RRkxRRLes7GIMVity6H1DSioOnCQkmJHMU+zlGeM4YY0xRCmovcIZ4ZpgdIfjbSlTO Mv8TENmDS8gkpKBW5CJG4D/UiTVsVVycfzNRkhTM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tabitha Sable , "Eric W. Biederman" , Tejun Heo , =?UTF-8?q?Michal=20Koutn=C3=BD?= Subject: [PATCH 4.9 1/2] cgroup-v1: Require capabilities to set release_agent Date: Wed, 9 Feb 2022 20:13:32 +0100 Message-Id: <20220209191247.878529283@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220209191247.830371456@linuxfoundation.org> References: <20220209191247.830371456@linuxfoundation.org> User-Agent: quilt/0.66 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric W. Biederman commit 24f6008564183aa120d07c03d9289519c2fe02af upstream. The cgroup release_agent is called with call_usermodehelper. The function call_usermodehelper starts the release_agent with a full set fo capabilitie= s. Therefore require capabilities when setting the release_agaent. Reported-by: Tabitha Sable Tested-by: Tabitha Sable Fixes: 81a6a5cdd2c5 ("Task Control Groups: automatic userspace notification= of idle cgroups") Cc: stable@vger.kernel.org # v2.6.24+ Signed-off-by: "Eric W. Biederman" Signed-off-by: Tejun Heo [mkoutny: Adjust for pre-fs_context, duplicate mount/remount check, drop lo= g messages.] Acked-by: Michal Koutn=C3=BD Signed-off-by: Greg Kroah-Hartman Tested-by: Florian Fainelli Tested-by: Guenter Roeck Tested-by: Linux Kernel Functional Testing Tested-by: Shuah Khan Tested-by: Slade Watkins --- kernel/cgroup.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1854,6 +1854,7 @@ static int cgroup_remount(struct kernfs_ { int ret =3D 0; struct cgroup_root *root =3D cgroup_root_from_kf(kf_root); + struct cgroup_namespace *ns =3D current->nsproxy->cgroup_ns; struct cgroup_sb_opts opts; u16 added_mask, removed_mask; =20 @@ -1873,6 +1874,13 @@ static int cgroup_remount(struct kernfs_ pr_warn("option changes via remount are deprecated (pid=3D%d comm=3D%s)\= n", task_tgid_nr(current), current->comm); =20 + /* See cgroup_mount release_agent handling */ + if (opts.release_agent && + ((ns->user_ns !=3D &init_user_ns) || !capable(CAP_SYS_ADMIN))) { + ret =3D -EINVAL; + goto out_unlock; + } + added_mask =3D opts.subsys_mask & ~root->subsys_mask; removed_mask =3D root->subsys_mask & ~opts.subsys_mask; =20 @@ -2248,6 +2256,16 @@ static struct dentry *cgroup_mount(struc goto out_unlock; } =20 + /* + * Release agent gets called with all capabilities, + * require capabilities to set release agent. + */ + if (opts.release_agent && + ((ns->user_ns !=3D &init_user_ns) || !capable(CAP_SYS_ADMIN))) { + ret =3D -EINVAL; + goto out_unlock; + } + root =3D kzalloc(sizeof(*root), GFP_KERNEL); if (!root) { ret =3D -ENOMEM; @@ -3026,6 +3044,14 @@ static ssize_t cgroup_release_agent_writ =20 BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX); =20 + /* + * Release agent gets called with all capabilities, + * require capabilities to set release agent. + */ + if ((of->file->f_cred->user_ns !=3D &init_user_ns) || + !capable(CAP_SYS_ADMIN)) + return -EPERM; + cgrp =3D cgroup_kn_lock_live(of->kn, false); if (!cgrp) return -ENODEV; From nobody Mon Jun 29 12:37:01 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9DF12C433EF for ; Wed, 9 Feb 2022 19:26:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234038AbiBIT0d (ORCPT ); Wed, 9 Feb 2022 14:26:33 -0500 Received: from gmail-smtp-in.l.google.com ([23.128.96.19]:46152 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234385AbiBIT0I (ORCPT ); Wed, 9 Feb 2022 14:26:08 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 049D5C102FED; Wed, 9 Feb 2022 11:19:55 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 5C3DEB8238C; Wed, 9 Feb 2022 19:14:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8C001C340E7; Wed, 9 Feb 2022 19:14:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1644434092; bh=eoZDwWkV4rsrAJOY5F0LAs5kTxbQ7KPvapYjwLwSSJI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kEi4yUF0j+4L2R7nkzZenYZutTMROVoJH+mMSQYop0n9IQFzvo6F2PAOTCsmbOrxf d7Wj+PUuuR3EYo3YlCcJJALAnj10VbXMvVpvCVcW8zg5VelhDKsgpU/+tEQfEfox0f nQO7lcjw4dXIuKbyKihcJegDtcw5kK2pKGMxnxvg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ulf Hansson , Xiyu Yang , Xin Xiong , Xin Tan , Tony Lindgren , Yang Li , linux-mmc@vger.kernel.org, whitehat002 Subject: [PATCH 4.9 2/2] moxart: fix potential use-after-free on remove path Date: Wed, 9 Feb 2022 20:13:33 +0100 Message-Id: <20220209191247.913724368@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220209191247.830371456@linuxfoundation.org> References: <20220209191247.830371456@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Greg Kroah-Hartman commit bd2db32e7c3e35bd4d9b8bbff689434a50893546 upstream. It was reported that the mmc host structure could be accessed after it was freed in moxart_remove(), so fix this by saving the base register of the device and using it instead of the pointer dereference. Cc: Ulf Hansson Cc: Xiyu Yang Cc: Xin Xiong Cc: Xin Tan Cc: Tony Lindgren Cc: Yang Li Cc: linux-mmc@vger.kernel.org Cc: stable Reported-by: whitehat002 Signed-off-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20220127071638.4057899-1-gregkh@linuxfounda= tion.org Signed-off-by: Ulf Hansson Signed-off-by: Greg Kroah-Hartman Tested-by: Florian Fainelli Tested-by: Guenter Roeck Tested-by: Linux Kernel Functional Testing Tested-by: Shuah Khan Tested-by: Slade Watkins --- drivers/mmc/host/moxart-mmc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/mmc/host/moxart-mmc.c +++ b/drivers/mmc/host/moxart-mmc.c @@ -698,12 +698,12 @@ static int moxart_remove(struct platform if (!IS_ERR(host->dma_chan_rx)) dma_release_channel(host->dma_chan_rx); mmc_remove_host(mmc); - mmc_free_host(mmc); =20 writel(0, host->base + REG_INTERRUPT_MASK); writel(0, host->base + REG_POWER_CONTROL); writel(readl(host->base + REG_CLOCK_CONTROL) | CLK_OFF, host->base + REG_CLOCK_CONTROL); + mmc_free_host(mmc); } return 0; }