Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755243AbaKEPni (ORCPT ); Wed, 5 Nov 2014 10:43:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50072 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753644AbaKEPnf (ORCPT ); Wed, 5 Nov 2014 10:43:35 -0500 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 7/7] SELinux: Check against union and lower labels for file ops on lower files From: David Howells To: linux-unionfs@vger.kernel.org, selinux@tycho.nsa.gov Cc: dhowells@redhat.com, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Date: Wed, 05 Nov 2014 15:43:29 +0000 Message-ID: <20141105154328.2555.98013.stgit@warthog.procyon.org.uk> In-Reply-To: <20141105154217.2555.578.stgit@warthog.procyon.org.uk> References: <20141105154217.2555.578.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.17-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org File operations (eg. read, write) issued against a file that is attached to the lower layer of a union file needs to be checked against the union-layer label as well as the lower-layer label. Signed-off-by: David Howells --- security/selinux/hooks.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 57f9c641779f..7084ccb1321c 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -1673,6 +1673,7 @@ static int file_has_perm(const struct cred *cred, struct file *file, u32 av) { + struct inode_security_struct *isec; struct file_security_struct *fsec = file->f_security; struct inode *inode = file_inode(file); struct common_audit_data ad; @@ -1681,7 +1682,7 @@ static int file_has_perm(const struct cred *cred, ad.type = LSM_AUDIT_DATA_PATH; ad.u.path = file->f_path; - + if (sid != fsec->sid) { rc = avc_has_perm(sid, fsec->sid, SECCLASS_FD, @@ -1693,8 +1694,15 @@ static int file_has_perm(const struct cred *cred, /* av is zero if only checking access to the descriptor. */ rc = 0; - if (av) - rc = inode_has_perm(cred, inode, av, &ad); + if (av && likely(!IS_PRIVATE(inode))) { + if (fsec->union_isid) { + isec = inode->i_security; + rc = avc_has_perm(sid, fsec->union_isid, isec->sclass, + av, &ad); + } + if (!rc) + rc = inode_has_perm(cred, inode, av, &ad); + } out: return rc; -- 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/