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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 22EDCC282C8 for ; Mon, 28 Jan 2019 16:10:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E713E2173C for ; Mon, 28 Jan 2019 16:10:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548691833; bh=KOsus9xJWb51QeK4RNQD+lzR12jV4nQQJ2SBBKX/baI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PJGxvvzwtIypS9C+b9RTC6dOCOreMFYe4S7xamw/mSJyuEBG4dEtO4+FN9mj46Rlo NsoWfa1EQL+rEG7/niZTC/Bc2cgty8CyQD142EE1I3ahE13sVXrSdZ1Qaq+wnoOJQ1 mJL6XoCB/jf1N/wQq8XtI7Ss/ChHWZbJPlG3No+I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732815AbfA1QKb (ORCPT ); Mon, 28 Jan 2019 11:10:31 -0500 Received: from mail.kernel.org ([198.145.29.99]:36464 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732345AbfA1QK3 (ORCPT ); Mon, 28 Jan 2019 11:10:29 -0500 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 12B7921738; Mon, 28 Jan 2019 16:10:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1548691829; bh=KOsus9xJWb51QeK4RNQD+lzR12jV4nQQJ2SBBKX/baI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eR4SnWTYuasN0EpG/SdNfGVQeJUG0hJxi4p8bASp9qtTIVOxoyOV/CC4AgLW2DoAI T9P9NdYijv8kRHI21c3mKnSmqUhGf0L3HXHT50f4yrm3fk+kGjSW0fMvMsQaP/CiHq /uIHN2xu0N7hsO9pi3UOHru0GMFfdVyHslkrUcH0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ondrej Mosnacek , Tejun Heo , Sasha Levin Subject: [PATCH AUTOSEL 4.19 231/258] cgroup: fix parsing empty mount option string Date: Mon, 28 Jan 2019 10:58:57 -0500 Message-Id: <20190128155924.51521-231-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190128155924.51521-1-sashal@kernel.org> References: <20190128155924.51521-1-sashal@kernel.org> MIME-Version: 1.0 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: Ondrej Mosnacek [ Upstream commit e250d91d65750a0c0c62483ac4f9f357e7317617 ] This fixes the case where all mount options specified are consumed by an LSM and all that's left is an empty string. In this case cgroupfs should accept the string and not fail. How to reproduce (with SELinux enabled): # umount /sys/fs/cgroup/unified # mount -o context=system_u:object_r:cgroup_t:s0 -t cgroup2 cgroup2 /sys/fs/cgroup/unified mount: /sys/fs/cgroup/unified: wrong fs type, bad option, bad superblock on cgroup2, missing codepage or helper program, or other error. # dmesg | tail -n 1 [ 31.575952] cgroup: cgroup2: unknown option "" Fixes: 67e9c74b8a87 ("cgroup: replace __DEVEL__sane_behavior with cgroup2 fs type") [NOTE: should apply on top of commit 5136f6365ce3 ("cgroup: implement "nsdelegate" mount option"), older versions need manual rebase] Suggested-by: Stephen Smalley Signed-off-by: Ondrej Mosnacek Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin --- kernel/cgroup/cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 1aa517908561..e578c3999970 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -1743,7 +1743,7 @@ static int parse_cgroup_root_flags(char *data, unsigned int *root_flags) *root_flags = 0; - if (!data) + if (!data || *data == '\0') return 0; while ((token = strsep(&data, ",")) != NULL) { -- 2.19.1