From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6DE9CC43612 for ; Thu, 17 Jan 2019 21:34:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4761820855 for ; Thu, 17 Jan 2019 21:34:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728802AbfAQVe0 (ORCPT ); Thu, 17 Jan 2019 16:34:26 -0500 Received: from mx2.suse.de ([195.135.220.15]:42674 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726821AbfAQVe0 (ORCPT ); Thu, 17 Jan 2019 16:34:26 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id DECBBAD05; Thu, 17 Jan 2019 21:34:23 +0000 (UTC) Date: Thu, 17 Jan 2019 15:34:21 -0600 From: Goldwyn Rodrigues To: Mimi Zohar Cc: Ignaz Forster , linux-integrity , linux-kernel , Fabian Vogt , Al Viro Subject: Re: [PATCH v2] ima: define ima_post_create_tmpfile() hook and add missing call Message-ID: <20190117213421.ggasuc263dpqh46c@merlin> References: <1545158873.4206.86.camel@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1545158873.4206.86.camel@linux.ibm.com> User-Agent: NeoMutt/20180323 Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On 13:47 18/12, Mimi Zohar wrote: > If tmpfiles can be made persistent, then newly created tmpfiles need to > be treated like any other new files in policy. > > This patch indicates which newly created tmpfiles are in policy, causing > the file hash to be calculated on __fput(). Discussed in overlayfs, this would be better if we use this on inode and called from vfs_tmpfile() instead of do_tmpfile(). This will cover the overlayfs case which uses tmpfiles while performing copy_up(). The patch is attached. Here is the updated patch which works for my cases. However, it is the the failure case after setting the IMA flags I am concerned about, though I don't think that should be as harmful. If tmpfiles can be made persistent, then newly created tmpfiles need to be treated like any other new files in policy. This patch indicates which newly created tmpfiles are in policy, causing the file hash to be calculated on __fput(). Reported-by: Ignaz Forster Signed-off-by: Mimi Zohar Signed-off-by: Goldwyn Rodrigues --- fs/namei.c | 1 + include/linux/ima.h | 6 ++++++ security/integrity/ima/ima_main.c | 35 +++++++++++++++++++++++++++++++++-- 3 files changed, 40 insertions(+), 2 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index 914178cdbe94..373a7ec4b09d 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3462,6 +3462,7 @@ struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode, int open_flag) inode->i_state |= I_LINKABLE; spin_unlock(&inode->i_lock); } + ima_post_create_tmpfile(inode); return child; out_err: diff --git a/include/linux/ima.h b/include/linux/ima.h index b5e16b8c50b7..32b0c5bdcd99 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -18,6 +18,7 @@ struct linux_binprm; #ifdef CONFIG_IMA extern int ima_bprm_check(struct linux_binprm *bprm); extern int ima_file_check(struct file *file, int mask); +extern void ima_post_create_tmpfile(struct inode *inode); extern void ima_file_free(struct file *file); extern int ima_file_mmap(struct file *file, unsigned long prot); extern int ima_load_data(enum kernel_load_data_id id); @@ -56,6 +57,11 @@ static inline int ima_file_check(struct file *file, int mask) return 0; } +static inline void ima_post_create_tmpfile(struct inode *inode) +{ + return; +} + static inline void ima_file_free(struct file *file) { return; diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 4ffac4f5c647..357edd140c09 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -396,6 +396,33 @@ int ima_file_check(struct file *file, int mask) } EXPORT_SYMBOL_GPL(ima_file_check); +/** + * ima_post_create_tmpfile - mark newly created tmpfile as new + * @file : newly created tmpfile + * + * No measuring, appraising or auditing of newly created tmpfiles is needed. + * Skip calling process_measurement(), but indicate which newly, created + * tmpfiles are in policy. + */ +void ima_post_create_tmpfile(struct inode *inode) +{ + struct integrity_iint_cache *iint; + int must_appraise; + + must_appraise = ima_must_appraise(inode, MAY_ACCESS, FILE_CHECK); + if (!must_appraise) + return; + + /* Nothing to do if we can't allocate memory */ + iint = integrity_inode_get(inode); + if (!iint) + return; + + /* needed for writing the security xattrs */ + set_bit(IMA_UPDATE_XATTR, &iint->atomic_flags); + iint->ima_file_status = INTEGRITY_PASS; +} + /** * ima_post_path_mknod - mark as a new inode * @dentry: newly created dentry @@ -413,9 +440,13 @@ void ima_post_path_mknod(struct dentry *dentry) if (!must_appraise) return; + /* Nothing to do if we can't allocate memory */ iint = integrity_inode_get(inode); - if (iint) - iint->flags |= IMA_NEW_FILE; + if (!iint) + return; + + /* needed for re-opening empty files */ + iint->flags |= IMA_NEW_FILE; } /** -- 2.16.4