From patchwork Wed Apr 7 10:52:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 12187821 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 09356C433ED for ; Wed, 7 Apr 2021 10:53:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BEBFE613A9 for ; Wed, 7 Apr 2021 10:53:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351619AbhDGKxZ (ORCPT ); Wed, 7 Apr 2021 06:53:25 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:2788 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351597AbhDGKxR (ORCPT ); Wed, 7 Apr 2021 06:53:17 -0400 Received: from fraeml714-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FFh1r3K6Fz686sR; Wed, 7 Apr 2021 18:48:00 +0800 (CST) Received: from fraphisprd00473.huawei.com (7.182.8.141) by fraeml714-chm.china.huawei.com (10.206.15.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Wed, 7 Apr 2021 12:53:06 +0200 From: Roberto Sassu To: , CC: , , , , Roberto Sassu , Casey Schaufler Subject: [PATCH v5 04/12] ima: Move ima_reset_appraise_flags() call to post hooks Date: Wed, 7 Apr 2021 12:52:44 +0200 Message-ID: <20210407105252.30721-5-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210407105252.30721-1-roberto.sassu@huawei.com> References: <20210407105252.30721-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [7.182.8.141] X-ClientProxiedBy: lhreml753-chm.china.huawei.com (10.201.108.203) To fraeml714-chm.china.huawei.com (10.206.15.33) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org ima_inode_setxattr() and ima_inode_removexattr() hooks are called before an operation is performed. Thus, ima_reset_appraise_flags() should not be called there, as flags might be unnecessarily reset if the operation is denied. This patch introduces the post hooks ima_inode_post_setxattr() and ima_inode_post_removexattr(), and adds the call to ima_reset_appraise_flags() in the new functions. Cc: Casey Schaufler Signed-off-by: Roberto Sassu --- fs/xattr.c | 2 ++ include/linux/ima.h | 18 ++++++++++++++++++ security/integrity/ima/ima_appraise.c | 25 ++++++++++++++++++++++--- security/security.c | 1 + 4 files changed, 43 insertions(+), 3 deletions(-) diff --git a/fs/xattr.c b/fs/xattr.c index b3444e06cded..81847f132d26 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include #include @@ -502,6 +503,7 @@ __vfs_removexattr_locked(struct user_namespace *mnt_userns, if (!error) { fsnotify_xattr(dentry); + ima_inode_post_removexattr(dentry, name); evm_inode_post_removexattr(dentry, name); } diff --git a/include/linux/ima.h b/include/linux/ima.h index 61d5723ec303..5e059da43857 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -171,7 +171,13 @@ extern void ima_inode_post_setattr(struct user_namespace *mnt_userns, struct dentry *dentry); extern int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name, const void *xattr_value, size_t xattr_value_len); +extern void ima_inode_post_setxattr(struct dentry *dentry, + const char *xattr_name, + const void *xattr_value, + size_t xattr_value_len); extern int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name); +extern void ima_inode_post_removexattr(struct dentry *dentry, + const char *xattr_name); #else static inline bool is_ima_appraise_enabled(void) { @@ -192,11 +198,23 @@ static inline int ima_inode_setxattr(struct dentry *dentry, return 0; } +static inline void ima_inode_post_setxattr(struct dentry *dentry, + const char *xattr_name, + const void *xattr_value, + size_t xattr_value_len) +{ +} + static inline int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name) { return 0; } + +static inline void ima_inode_post_removexattr(struct dentry *dentry, + const char *xattr_name) +{ +} #endif /* CONFIG_IMA_APPRAISE */ #if defined(CONFIG_IMA_APPRAISE) && defined(CONFIG_INTEGRITY_TRUSTED_KEYRING) diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c index 565e33ff19d0..1f029e4c8d7f 100644 --- a/security/integrity/ima/ima_appraise.c +++ b/security/integrity/ima/ima_appraise.c @@ -577,21 +577,40 @@ int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name, if (result == 1) { if (!xattr_value_len || (xvalue->type >= IMA_XATTR_LAST)) return -EINVAL; - ima_reset_appraise_flags(d_backing_inode(dentry), - xvalue->type == EVM_IMA_XATTR_DIGSIG); result = 0; } return result; } +void ima_inode_post_setxattr(struct dentry *dentry, const char *xattr_name, + const void *xattr_value, size_t xattr_value_len) +{ + const struct evm_ima_xattr_data *xvalue = xattr_value; + int result; + + result = ima_protect_xattr(dentry, xattr_name, xattr_value, + xattr_value_len); + if (result == 1) + ima_reset_appraise_flags(d_backing_inode(dentry), + xvalue->type == EVM_IMA_XATTR_DIGSIG); +} + int ima_inode_removexattr(struct dentry *dentry, const char *xattr_name) { int result; result = ima_protect_xattr(dentry, xattr_name, NULL, 0); if (result == 1) { - ima_reset_appraise_flags(d_backing_inode(dentry), 0); result = 0; } return result; } + +void ima_inode_post_removexattr(struct dentry *dentry, const char *xattr_name) +{ + int result; + + result = ima_protect_xattr(dentry, xattr_name, NULL, 0); + if (result == 1) + ima_reset_appraise_flags(d_backing_inode(dentry), 0); +} diff --git a/security/security.c b/security/security.c index 5ac96b16f8fa..efb1f874dc41 100644 --- a/security/security.c +++ b/security/security.c @@ -1319,6 +1319,7 @@ void security_inode_post_setxattr(struct dentry *dentry, const char *name, if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) return; call_void_hook(inode_post_setxattr, dentry, name, value, size, flags); + ima_inode_post_setxattr(dentry, name, value, size); evm_inode_post_setxattr(dentry, name, value, size); }