From patchwork Wed Mar 13 09:50:50 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Pisati X-Patchwork-Id: 227218 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 5DF112C02AE for ; Wed, 13 Mar 2013 20:51:16 +1100 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UFiKz-0001ox-WD; Wed, 13 Mar 2013 09:51:09 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UFiKp-0001ep-Ni for kernel-team@lists.ubuntu.com; Wed, 13 Mar 2013 09:50:59 +0000 Received: from 2-230-238-136.ip204.fastwebnet.it ([2.230.238.136] helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UFiKp-0000u8-Ki for kernel-team@lists.ubuntu.com; Wed, 13 Mar 2013 09:50:59 +0000 From: Paolo Pisati To: kernel-team@lists.ubuntu.com Subject: [PATCH 10/11] UBUNTU: ubuntu: overlayfs -- overlayfs: apply device cgroup and security permissions to overlay files Date: Wed, 13 Mar 2013 10:50:50 +0100 Message-Id: <1363168251-9374-11-git-send-email-paolo.pisati@canonical.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1363168251-9374-1-git-send-email-paolo.pisati@canonical.com> References: <1363168251-9374-1-git-send-email-paolo.pisati@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com From: Andy Whitcroft When checking permissions on an overlayfs inode we do not take into account either device cgroup restrictions nor security permissions. This allows a user to mount an overlayfs layer over a restricted device directory and by pass those permissions to open otherwise restricted files. Use devcgroup_inode_permission() and security_inode_permission() against the underlying inodes when calculating ovl_permission(). CVE-2012-0055 BugLink: http://bugs.launchpad.net/bugs/915941 BugLink: http://bugs.launchpad.net/bugs/918212 Signed-off-by: Andy Whitcroft (cherry picked from commit 59aa87f808b13463bc717ad69362b5372f6c5574) BugLink: http://bugs.launchpad.net/bugs/1076317 Signed-off-by: Paolo Pisati --- fs/overlayfs/inode.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index ba1a777..1145a76 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -10,6 +10,8 @@ #include #include #include +#include +#include #include "overlayfs.h" int ovl_setattr(struct dentry *dentry, struct iattr *attr) @@ -118,6 +120,11 @@ int ovl_permission(struct inode *inode, int mask) err = realinode->i_op->permission(realinode, mask); else err = generic_permission(realinode, mask); + + if (!err) + err = devcgroup_inode_permission(realinode, mask); + if (!err) + err = security_inode_permission(realinode, mask); out_dput: dput(alias); return err;