From patchwork Mon Nov 20 17:33:09 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13461792 X-Patchwork-Delegate: paul@paul-moore.com Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 44CFAC5AD4C for ; Mon, 20 Nov 2023 17:39:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234121AbjKTRjj (ORCPT ); Mon, 20 Nov 2023 12:39:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59022 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234123AbjKTRjN (ORCPT ); Mon, 20 Nov 2023 12:39:13 -0500 Received: from frasgout12.his.huawei.com (frasgout12.his.huawei.com [14.137.139.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2235B19A; Mon, 20 Nov 2023 09:38:46 -0800 (PST) Received: from mail02.huawei.com (unknown [172.18.147.228]) by frasgout12.his.huawei.com (SkyGuard) with ESMTP id 4SYvSs3rfpz9xxmv; Tue, 21 Nov 2023 01:22:05 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP2 (Coremail) with SMTP id GxC2BwAHuGEqmVtlz4kHAQ--.4148S8; Mon, 20 Nov 2023 18:38:18 +0100 (CET) From: Roberto Sassu To: viro@zeniv.linux.org.uk, brauner@kernel.org, chuck.lever@oracle.com, jlayton@kernel.org, neilb@suse.de, kolga@netapp.com, Dai.Ngo@oracle.com, tom@talpey.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, zohar@linux.ibm.com, dmitry.kasatkin@gmail.com, dhowells@redhat.com, jarkko@kernel.org, stephen.smalley.work@gmail.com, eparis@parisplace.org, casey@schaufler-ca.com, mic@digikod.net Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-security-module@vger.kernel.org, linux-integrity@vger.kernel.org, keyrings@vger.kernel.org, selinux@vger.kernel.org, Roberto Sassu , Stefan Berger Subject: [PATCH v6 16/25] security: Introduce inode_post_set_acl hook Date: Mon, 20 Nov 2023 18:33:09 +0100 Message-Id: <20231120173318.1132868-17-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231120173318.1132868-1-roberto.sassu@huaweicloud.com> References: <20231120173318.1132868-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: GxC2BwAHuGEqmVtlz4kHAQ--.4148S8 X-Coremail-Antispam: 1UD129KBjvJXoWxuryDCFWrXr1UXr15Gw18Grg_yoWrWw4kpF 4ft3Za93yrXFy7WryvyF4DC34SqFW5Kry7J392gw1SyFn7tr1jqFsIkFyYkFyrArW8GF1v gF4a9rsxC345Jr7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPab4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUAV Cq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0 rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI8IcVCY1x0267 AKxVWxJr0_GcWl84ACjcxK6I8E87Iv67AKxVWxJVW8Jr1l84ACjcxK6I8E87Iv6xkF7I0E 14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7 xfMcIj6xIIjxv20xvE14v26r126r1DMcIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Y z7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxVAaw2 AFwI0_GFv_Wryl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAq x4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6r W5MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Ar0_tr1lIxAIcVC0I7IYx2IY6xkF 7I0E14v26F4UJVW0owCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI 0_Gr0_Cr1lIxAIcVC2z280aVCY1x0267AKxVW0oVCq3bIYCTnIWIevJa73UjIFyTuYvjxU IrWFUUUUU X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAQAHBF1jj5apfgAAsy X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org From: Roberto Sassu In preparation for moving IMA and EVM to the LSM infrastructure, introduce the inode_post_set_acl hook. At inode_set_acl hook, EVM verifies the file's existing HMAC value. At inode_post_set_acl, EVM re-calculates the file's HMAC based on the modified POSIX ACL and other file metadata. Other LSMs could similarly take some action after successful POSIX ACL change. The new hook cannot return an error and cannot cause the operation to be reverted. Signed-off-by: Roberto Sassu Reviewed-by: Stefan Berger Acked-by: Casey Schaufler Reviewed-by: Mimi Zohar --- fs/posix_acl.c | 1 + include/linux/lsm_hook_defs.h | 2 ++ include/linux/security.h | 7 +++++++ security/security.c | 17 +++++++++++++++++ 4 files changed, 27 insertions(+) diff --git a/fs/posix_acl.c b/fs/posix_acl.c index a05fe94970ce..58e3c1e2fbbc 100644 --- a/fs/posix_acl.c +++ b/fs/posix_acl.c @@ -1137,6 +1137,7 @@ int vfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, error = -EIO; if (!error) { fsnotify_xattr(dentry); + security_inode_post_set_acl(dentry, acl_name, kacl); evm_inode_post_set_acl(dentry, acl_name, kacl); } diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 4b195996f848..5133dd88b5fb 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -157,6 +157,8 @@ LSM_HOOK(void, LSM_RET_VOID, inode_post_removexattr, struct dentry *dentry, const char *name) LSM_HOOK(int, 0, inode_set_acl, struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name, struct posix_acl *kacl) +LSM_HOOK(void, LSM_RET_VOID, inode_post_set_acl, struct dentry *dentry, + const char *acl_name, struct posix_acl *kacl) LSM_HOOK(int, 0, inode_get_acl, struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name) LSM_HOOK(int, 0, inode_remove_acl, struct mnt_idmap *idmap, diff --git a/include/linux/security.h b/include/linux/security.h index d77b717b5a45..948aaddf0edd 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -372,6 +372,8 @@ int security_inode_setxattr(struct mnt_idmap *idmap, int security_inode_set_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name, struct posix_acl *kacl); +void security_inode_post_set_acl(struct dentry *dentry, const char *acl_name, + struct posix_acl *kacl); int security_inode_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name); int security_inode_remove_acl(struct mnt_idmap *idmap, @@ -913,6 +915,11 @@ static inline int security_inode_set_acl(struct mnt_idmap *idmap, return 0; } +static inline void security_inode_post_set_acl(struct dentry *dentry, + const char *acl_name, + struct posix_acl *kacl) +{ } + static inline int security_inode_get_acl(struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name) diff --git a/security/security.c b/security/security.c index a1bdf4859448..5d25bbd18d66 100644 --- a/security/security.c +++ b/security/security.c @@ -2350,6 +2350,23 @@ int security_inode_set_acl(struct mnt_idmap *idmap, return evm_inode_set_acl(idmap, dentry, acl_name, kacl); } +/** + * security_inode_post_set_acl() - Update inode security from posix acls set + * @dentry: file + * @acl_name: acl name + * @kacl: acl struct + * + * Update inode security data after successfully setting posix acls on @dentry. + * The posix acls in @kacl are identified by @acl_name. + */ +void security_inode_post_set_acl(struct dentry *dentry, const char *acl_name, + struct posix_acl *kacl) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(inode_post_set_acl, dentry, acl_name, kacl); +} + /** * security_inode_get_acl() - Check if reading posix acls is allowed * @idmap: idmap of the mount