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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT autolearn=unavailable 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 BF186C169C4 for ; Mon, 11 Feb 2019 15:57:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8DC4B21B24 for ; Mon, 11 Feb 2019 15:57:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549900668; bh=mtvvRI3wp9+pV9E1Y73ZMdakdEsymN7zWb1ePqQQc88=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=WYGR4++EQmsMQ9T62Ef009iqKDC79pUV30V844UnyYIw1KsdweAx1fLNTgMwKI29w OjnyFZBW/3pAoO7+Nugqznst7w9jJ0iYp705h0UyE+waKuls/bbYS//C9wMBCSfVhV StHRx3Vftd7Wpf8KTwSNCZz3sYJFJn+sczeiIwPI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730393AbfBKOde (ORCPT ); Mon, 11 Feb 2019 09:33:34 -0500 Received: from mail.kernel.org ([198.145.29.99]:41262 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730648AbfBKOda (ORCPT ); Mon, 11 Feb 2019 09:33:30 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 394C520844; Mon, 11 Feb 2019 14:33:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1549895609; bh=mtvvRI3wp9+pV9E1Y73ZMdakdEsymN7zWb1ePqQQc88=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EJHYGCZsSUoT3jPtleyz682uylD2eP8AwRLdMv4bMRWFJRu1QIWwhOoKeqNbSt4EZ 9KhbrVE0hqDNJeR5vCP57ZO0iSkfPSTyu6cBc/B1YB31dt5VBKyVwtfDUVkVhsh/9S uhsdphheWZf6hdKn/WUYA0n9Fse8JzZN7ZGNHV1E= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Stephen Smalley , Ondrej Mosnacek , Tejun Heo , Sasha Levin Subject: [PATCH 4.20 262/352] cgroup: fix parsing empty mount option string Date: Mon, 11 Feb 2019 15:18:09 +0100 Message-Id: <20190211141903.715636746@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190211141846.543045703@linuxfoundation.org> References: <20190211141846.543045703@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ 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 1f84977fab47..498c6bcf992a 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -1744,7 +1744,7 @@ 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