From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:35336 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732407AbeKLISG (ORCPT ); Mon, 12 Nov 2018 03:18:06 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dmitry Vyukov , Waiman Long , Stephen Smalley , Paul Moore Subject: [PATCH 4.19 231/361] selinux: fix mounting of cgroup2 under older policies Date: Sun, 11 Nov 2018 14:19:38 -0800 Message-Id: <20181111221651.548385501@linuxfoundation.org> In-Reply-To: <20181111221619.915519183@linuxfoundation.org> References: <20181111221619.915519183@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stephen Smalley commit 7bb185edb0306bb90029a5fa6b9cff900ffdbf4b upstream. commit 901ef845fa2469c ("selinux: allow per-file labeling for cgroupfs") broke mounting of cgroup2 under older SELinux policies which lacked a genfscon rule for cgroup2. This prevents mounting of cgroup2 even when SELinux is permissive. Change the handling when there is no genfscon rule in policy to just mark the inode unlabeled and not return an error to the caller. This permits mounting and access if allowed by policy, e.g. to unconfined domains. I also considered changing the behavior of security_genfs_sid() to never return -ENOENT, but the current behavior is relied upon by other callers to perform caller-specific handling. Fixes: 901ef845fa2469c ("selinux: allow per-file labeling for cgroupfs") CC: Reported-by: Dmitry Vyukov Reported-by: Waiman Long Signed-off-by: Stephen Smalley Tested-by: Waiman Long Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman --- security/selinux/hooks.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1508,6 +1508,11 @@ static int selinux_genfs_get_sid(struct } rc = security_genfs_sid(&selinux_state, sb->s_type->name, path, tclass, sid); + if (rc == -ENOENT) { + /* No match in policy, mark as unlabeled. */ + *sid = SECINITSID_UNLABELED; + rc = 0; + } } free_page((unsigned long)buffer); return rc;