From patchwork Mon Jan 4 18:03:52 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Seth Forshee X-Patchwork-Id: 7950241 Return-Path: X-Original-To: patchwork-selinux@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 823DD9F1CC for ; Mon, 4 Jan 2016 18:44:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CD0CC20304 for ; Mon, 4 Jan 2016 18:44:45 +0000 (UTC) Received: from emvm-gh1-uea08.nsa.gov (emvm-gh1-uea08.nsa.gov [63.239.67.9]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EDA8F20155 for ; Mon, 4 Jan 2016 18:44:44 +0000 (UTC) X-TM-IMSS-Message-ID: <75d9ff5f001043d5@nsa.gov> Received: from tarius.tycho.ncsc.mil ([144.51.242.1]) by nsa.gov ([10.208.42.193]) with ESMTP (TREND IMSS SMTP Service 7.1) id 75d9ff5f001043d5 ; Mon, 4 Jan 2016 13:42:49 -0500 Received: from prometheus.infosec.tycho.ncsc.mil (prometheus [192.168.25.40]) by tarius.tycho.ncsc.mil (8.14.4/8.14.4) with ESMTP id u04Ifqr8017507; Mon, 4 Jan 2016 13:41:54 -0500 Received: from tarius.tycho.ncsc.mil (tarius.infosec.tycho.ncsc.mil [144.51.242.1]) by prometheus.infosec.tycho.ncsc.mil (8.15.2/8.15.2) with ESMTP id u04I4gNB225783 for ; Mon, 4 Jan 2016 13:04:42 -0500 Received: from goalie.tycho.ncsc.mil (goalie [144.51.242.250]) by tarius.tycho.ncsc.mil (8.14.4/8.14.4) with ESMTP id u04I4gpH013588 for ; Mon, 4 Jan 2016 13:04:42 -0500 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A1CSAAAys4pWm7TVVdFeGQEBAQEPAQEBAYRJiFm1aIYPAoFoAQEBAQEBEgEBAQEBBgsLCSGEYwEBAQMSFRkBATcBD1E0AQUBHAYBEiKIDaJOgTE+MYpXhVQBBYweAQEBAQEBBAIBGgYKhDuCEY47jjWIVo8thz0xhTFEjCo1gReCaCKCA1MBhQ8BAQE X-IPAS-Result: A1CSAAAys4pWm7TVVdFeGQEBAQEPAQEBAYRJiFm1aIYPAoFoAQEBAQEBEgEBAQEBBgsLCSGEYwEBAQMSFRkBATcBD1E0AQUBHAYBEiKIDaJOgTE+MYpXhVQBBYweAQEBAQEBBAIBGgYKhDuCEY47jjWIVo8thz0xhTFEjCo1gReCaCKCA1MBhQ8BAQE X-IronPort-AV: E=Sophos;i="5.20,521,1444708800"; d="scan'208";a="5070761" Received: from emvm-gh1-uea08.nsa.gov ([10.208.42.193]) by goalie.tycho.ncsc.mil with ESMTP; 04 Jan 2016 13:04:41 -0500 X-TM-IMSS-Message-ID: <75b6b390001034a1@nsa.gov> Received: from mail-ig0-f180.google.com (mail-ig0-f180.google.com [209.85.213.180]) by nsa.gov ([10.208.42.193]) with ESMTP (TREND IMSS SMTP Service 7.1; TLSv1/SSLv3 AES128-SHA (128/128)) id 75b6b390001034a1 ; Mon, 4 Jan 2016 13:04:16 -0500 Received: by mail-ig0-f180.google.com with SMTP id ik10so192927igb.1 for ; Mon, 04 Jan 2016 10:04:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=amcOvjSJibxe9D0J1vUSJTc4CWm1bFCnFTdrUcC934M=; b=SjDCw1bU1sdlycv5aKZgGqsiW/PJTkK2QGikZRhg+suUCzhpN5tXpcDFCnVnX6GhTI fV3ea9/1GGL043c8UKh+ZZJvjwLipDkXjduVILgLt/51EazbdNI/VQp8QOtQZ5hemi2C 1hF4ZX5l4POt15S1LN/dBSc394xt8K9cZB4NZWnrKndSja07/LNHSSiLJruVfD1JCGnC 1b26kfaUkGQMgi6xMZrTMFn1zuWDVOg9DnWkiw1TUhqPcmw/Phq7Zhr7KzdJ8UrNNBsZ SAnnlYcY5Yu59jNRf9lCGWGjneZ+XVoCoZl3m5+WyeQB4c4w6uGznsdkhp4jPmkV0ut6 nFSA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=amcOvjSJibxe9D0J1vUSJTc4CWm1bFCnFTdrUcC934M=; b=QNxpAKYn+SdznlyJvvcV/AwWKP9RHO676VbeEu6d0NFwRJfHnWIuHe0glZjeGcfg+l lxm/FsZt65ZxJtOc+Hxc//N+hBv83Aj342LYtnb81wkMPKoMzKPOwmggFw6xgp6nkOd0 F/Ef9Kq8aM5NDklmqzNT7PuDgHudG/xYIlpIdEzNh6+Xw/RIP+1kkQou2zXNJF+jGC8d P6sQO96WoTKqA/ktZtvghTjMd/maGF/EvRmKn9QwhO9VhaT4KJpmvIvwSd2UnedSWmoe yaCYjyQp7zjfj1xrK7j4TtFghbxqtJpEetNwyxbVL6F/Fz+95xp2J6acOQSoH8kXCuht 6x9A== X-Gm-Message-State: ALoCoQmQKOfgWj0c8dnDk5v0zEf6zz9gXA610UtxJN7Wam2XT9J/xg26WEii3jbdpbM7e2SQb2itLJ+6Ah/CyN22pcO+y1Jv1w== X-Received: by 10.50.79.234 with SMTP id m10mr30692716igx.23.1451930679979; Mon, 04 Jan 2016 10:04:39 -0800 (PST) Received: from localhost ([66.64.121.229]) by smtp.gmail.com with ESMTPSA id kc8sm16124479igb.4.2016.01.04.10.04.39 (version=TLS1_2 cipher=AES128-SHA bits=128/128); Mon, 04 Jan 2016 10:04:39 -0800 (PST) From: Seth Forshee To: "Eric W. Biederman" , Alexander Viro Subject: [PATCH RESEND v2 13/18] fs: Allow superblock owner to access do_remount_sb() Date: Mon, 4 Jan 2016 12:03:52 -0600 Message-Id: <1451930639-94331-14-git-send-email-seth.forshee@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1451930639-94331-1-git-send-email-seth.forshee@canonical.com> References: <1451930639-94331-1-git-send-email-seth.forshee@canonical.com> X-TM-AS-MML: disable X-Mailman-Approved-At: Mon, 04 Jan 2016 13:14:22 -0500 X-BeenThere: selinux@tycho.nsa.gov X-Mailman-Version: 2.1.20 Precedence: list List-Id: "Security-Enhanced Linux \(SELinux\) mailing list" List-Post: List-Help: Cc: Serge Hallyn , Seth Forshee , dm-devel@redhat.com, Miklos Szeredi , Richard Weinberger , linux-security-module@vger.kernel.org, linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, fuse-devel@lists.sourceforge.net, Austin S Hemmelgarn , linux-mtd@lists.infradead.org, selinux@tycho.nsa.gov, linux-fsdevel@vger.kernel.org MIME-Version: 1.0 Errors-To: selinux-bounces@tycho.nsa.gov Sender: "Selinux" X-Spam-Status: No, score=-6.8 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Superblock level remounts are currently restricted to global CAP_SYS_ADMIN, as is the path for changing the root mount to read only on umount. Loosen both of these permission checks to also allow CAP_SYS_ADMIN in any namespace which is privileged towards the userns which originally mounted the filesystem. Signed-off-by: Seth Forshee Acked-by: "Eric W. Biederman" Acked-by: Serge Hallyn --- fs/namespace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 18fc58760aec..b00a765895e7 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -1510,7 +1510,7 @@ static int do_umount(struct mount *mnt, int flags) * Special case for "unmounting" root ... * we just try to remount it readonly. */ - if (!capable(CAP_SYS_ADMIN)) + if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) return -EPERM; down_write(&sb->s_umount); if (!(sb->s_flags & MS_RDONLY)) @@ -2199,7 +2199,7 @@ static int do_remount(struct path *path, int flags, int mnt_flags, down_write(&sb->s_umount); if (flags & MS_BIND) err = change_mount_flags(path->mnt, flags); - else if (!capable(CAP_SYS_ADMIN)) + else if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) err = -EPERM; else err = do_remount_sb(sb, flags, data, 0);