From patchwork Wed Aug 16 17:30:20 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mimi Zohar X-Patchwork-Id: 9904387 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 1537A603FB for ; Wed, 16 Aug 2017 17:31:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F24AF28A5C for ; Wed, 16 Aug 2017 17:31:09 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id F09BF28A5B; Wed, 16 Aug 2017 17:31:09 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 747B828949 for ; Wed, 16 Aug 2017 17:31:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752064AbdHPRat (ORCPT ); Wed, 16 Aug 2017 13:30:49 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:54262 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752031AbdHPRar (ORCPT ); Wed, 16 Aug 2017 13:30:47 -0400 Received: from pps.filterd (m0098404.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v7GHSpmo058179 for ; Wed, 16 Aug 2017 13:30:47 -0400 Received: from e23smtp07.au.ibm.com (e23smtp07.au.ibm.com [202.81.31.140]) by mx0a-001b2d01.pphosted.com with ESMTP id 2ccrk2ers4-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 16 Aug 2017 13:30:47 -0400 Received: from localhost by e23smtp07.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Thu, 17 Aug 2017 03:30:43 +1000 Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay08.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v7GHUg8l42401952; Thu, 17 Aug 2017 03:30:42 +1000 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v7GHUfXZ014856; Thu, 17 Aug 2017 03:30:42 +1000 Received: from localhost.localdomain.com ([9.80.83.117]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id v7GHUNh9014102; Thu, 17 Aug 2017 03:30:39 +1000 From: Mimi Zohar To: Christoph Hellwig , Al Viro Cc: Jan Kara , Jeff Layton , Mimi Zohar , linux-fsdevel@vger.kernel.org, linux-ima-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org Subject: [RFC PATCH 4/4] ima: define a new ima_sb_post_remount hook Date: Wed, 16 Aug 2017 13:30:20 -0400 X-Mailer: git-send-email 2.7.4 In-Reply-To: <1502904620-20075-1-git-send-email-zohar@linux.vnet.ibm.com> References: <1502904620-20075-1-git-send-email-zohar@linux.vnet.ibm.com> X-TM-AS-MML: disable x-cbid: 17081617-0044-0000-0000-00000282BDDD X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17081617-0045-0000-0000-00000715E647 Message-Id: <1502904620-20075-5-git-send-email-zohar@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-08-16_07:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1707230000 definitions=main-1708160288 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Compare the previous i_version flag with the remounted i_version flag. Only if there is a change, log change message. Signed-off-by: Mimi Zohar --- include/linux/ima.h | 9 +++++++++ security/integrity/ima/ima_main.c | 22 ++++++++++++++++++++-- security/security.c | 1 + 3 files changed, 30 insertions(+), 2 deletions(-) diff --git a/include/linux/ima.h b/include/linux/ima.h index 4475cb01149c..bd98221c00d5 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -25,6 +25,9 @@ extern int ima_post_read_file(struct file *file, void *buf, loff_t size, extern void ima_post_path_mknod(struct dentry *dentry); extern void ima_sb_post_new_mount(const struct vfsmount *newmnt, const struct path *path); +extern void ima_sb_post_remount(const struct super_block *sb, + unsigned long prev_sb_flags, + const struct path *path); #ifdef CONFIG_IMA_KEXEC extern void ima_add_kexec_buffer(struct kimage *image); @@ -70,6 +73,12 @@ static inline void ima_post_path_mknod(struct dentry *dentry) static inline void ima_sb_post_new_mount(const struct vfsmount *newmnt, const struct path *path) { } + +static inline void ima_sb_post_remount(const struct super_block *sb, + unsigned long prev_sb_flags, + const struct path *path) +{ } + #endif /* CONFIG_IMA */ #ifndef CONFIG_IMA_KEXEC diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index a0a685189001..1b180f974e8d 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -373,8 +373,10 @@ void ima_sb_post_new_mount(const struct vfsmount *newmnt, sb = newmnt ? newmnt->mnt_sb : path->mnt->mnt_sb; - if ((sb->s_flags & MS_I_VERSION) || (sb->s_flags & MS_RDONLY) || - (sb->s_flags & MS_KERNMOUNT)) + if ((sb->s_flags & MS_KERNMOUNT) || (sb->s_flags & MS_RDONLY)) + return; + + if (newmnt && (sb->s_flags & MS_I_VERSION)) return; for (i = 0; i < ARRAY_SIZE(pseudo_fs); i++) { @@ -394,9 +396,25 @@ void ima_sb_post_new_mount(const struct vfsmount *newmnt, if (newmnt) pr_warn("ima: %s mounted without i_version enabled\n", pathname); + else if (sb->s_flags & MS_I_VERSION) + pr_warn("ima: %s re-mounted with i_version enabled\n", + pathname); + else + pr_warn("ima: %s re-mounted without i_version enabled\n", + pathname); __putname(pathbuf); } +void ima_sb_post_remount(const struct super_block *sb, + unsigned long prev_sb_flags, + const struct path *path) +{ + if ((sb->s_flags & MS_I_VERSION) == (prev_sb_flags & MS_I_VERSION)) + return; /* nothing changed */ + + ima_sb_post_new_mount(NULL, path); +} + /** * ima_read_file - pre-measure/appraise hook decision based on policy * @file: pointer to the file to be measured/appraised/audit diff --git a/security/security.c b/security/security.c index 7981ad9019c9..1e2051a52b9f 100644 --- a/security/security.c +++ b/security/security.c @@ -382,6 +382,7 @@ void security_sb_post_remount(const struct super_block *sb, const struct path *path) { call_void_hook(sb_post_remount, sb, prev_sb_flags, path); + ima_sb_post_remount(sb, prev_sb_flags, path); } int security_sb_kern_mount(struct super_block *sb, int flags, void *data)