Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422714AbXBHXDe (ORCPT ); Thu, 8 Feb 2007 18:03:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933346AbXBHXDe (ORCPT ); Thu, 8 Feb 2007 18:03:34 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:37158 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161390AbXBHXDd (ORCPT ); Thu, 8 Feb 2007 18:03:33 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Andrew Morton Cc: Stephen Smalley , Ingo Molnar , tglx@linutronix.de, linux-kernel@vger.kernel.org, selinux@tycho.nsa.gov, James Morris Subject: [PATCH 4/5] selinux: Enhance selinux to always ignore private inodes. References: <200701280106.l0S16CG3019873@shell0.pdx.osdl.net> <20070128003549.2ca38dc8.akpm@osdl.org> <20070128093358.GA2071@elte.hu> <20070128095712.GA6485@elte.hu> <20070128100627.GA8416@elte.hu> <20070128104548.a835d859.akpm@osdl.org> <1170075866.8720.15.camel@moss-spartans.epoch.ncsc.mil> <1170872654.11912.87.camel@moss-spartans.epoch.ncsc.mil> <1170882738.11912.144.camel@moss-spartans.epoch.ncsc.mil> <1170946871.11912.250.camel@moss-spartans.epoch.ncsc.mil> <1170958404.11912.313.camel@moss-spartans.epoch.ncsc.mil> Date: Thu, 08 Feb 2007 16:02:58 -0700 In-Reply-To: (Eric W. Biederman's message of "Thu, 08 Feb 2007 15:55:41 -0700") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1625 Lines: 43 From: Stephen Smalley Hmmm...turns out to not be quite enough, as the /proc/sys inodes aren't truly private to the fs, so we can run into them in a variety of security hooks beyond just the inode hooks, such as security_file_permission (when reading and writing them via the vfs helpers), security_sb_mount (when mounting other filesystems on directories in proc like binfmt_misc), and deeper within the security module itself (as in flush_unauthorized_files upon inheritance across execve). So I think we have to add an IS_PRIVATE() guard within SELinux, as below. Note however that the use of the private flag here could be confusing, as these inodes are _not_ private to the fs, are exposed to userspace, and security modules must implement the sysctl hook to get any access control over them. Signed-off-by: Eric W. Biederman --- security/selinux/hooks.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index de16b9f..ff9fccc 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1077,6 +1077,9 @@ static int inode_has_perm(struct task_struct *tsk, struct inode_security_struct *isec; struct avc_audit_data ad; + if (unlikely (IS_PRIVATE (inode))) + return 0; + tsec = tsk->security; isec = inode->i_security; -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/