From patchwork Mon Nov 20 17:33:08 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13461748 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 268B1C5AD4C for ; Mon, 20 Nov 2023 17:39:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234196AbjKTRjS (ORCPT ); Mon, 20 Nov 2023 12:39:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234195AbjKTRi5 (ORCPT ); Mon, 20 Nov 2023 12:38:57 -0500 Received: from frasgout13.his.huawei.com (frasgout13.his.huawei.com [14.137.139.46]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B71DDD69; Mon, 20 Nov 2023 09:38:32 -0800 (PST) Received: from mail02.huawei.com (unknown [172.18.147.228]) by frasgout13.his.huawei.com (SkyGuard) with ESMTP id 4SYvX84lFnz9yMKb; Tue, 21 Nov 2023 01:24:56 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP2 (Coremail) with SMTP id GxC2BwAHuGEqmVtlz4kHAQ--.4148S7; Mon, 20 Nov 2023 18:38:04 +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 Subject: [PATCH v6 15/25] security: Introduce inode_post_create_tmpfile hook Date: Mon, 20 Nov 2023 18:33:08 +0100 Message-Id: <20231120173318.1132868-16-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--.4148S7 X-Coremail-Antispam: 1UD129KBjvJXoWxWFyUZF4kuw4UJr45uw1fXrb_yoWrGw48pF WfK3W5Gws5XFy7WryvyF47uw1Sgay5WrWUJrZagwn0yFn7tr1ftF1Skr12kF13JrW8Gw1I q3ZFkrZxGr17trJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPSb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 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_Cr1lIxAIcVC2z280aVCY1x0267AKxVWxJr0_GcJvcSsGvfC2KfnxnUUI43ZEXa7I U04rW7UUUUU== X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAgAHBF1jj5KqcAAAs4 X-CFilter-Loop: Reflected Precedence: bulk List-ID: From: Roberto Sassu In preparation for moving IMA and EVM to the LSM infrastructure, introduce the inode_post_create_tmpfile hook. As temp files can be made persistent, treat new temp files like other new files, so that the file hash is calculated and stored in the security xattr. LSMs could also take some action after temp files have been created. The new hook cannot return an error and cannot cause the operation to be canceled. Signed-off-by: Roberto Sassu Acked-by: Casey Schaufler Reviewed-by: Mimi Zohar --- fs/namei.c | 1 + include/linux/lsm_hook_defs.h | 2 ++ include/linux/security.h | 6 ++++++ security/security.c | 15 +++++++++++++++ 4 files changed, 24 insertions(+) diff --git a/fs/namei.c b/fs/namei.c index b7f433720b1e..adb3ab27951a 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -3686,6 +3686,7 @@ static int vfs_tmpfile(struct mnt_idmap *idmap, inode->i_state |= I_LINKABLE; spin_unlock(&inode->i_lock); } + security_inode_post_create_tmpfile(idmap, inode); ima_post_create_tmpfile(idmap, inode); return 0; } diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index ee5ab180a312..4b195996f848 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -121,6 +121,8 @@ LSM_HOOK(int, 0, inode_init_security_anon, struct inode *inode, const struct qstr *name, const struct inode *context_inode) LSM_HOOK(int, 0, inode_create, struct inode *dir, struct dentry *dentry, umode_t mode) +LSM_HOOK(void, LSM_RET_VOID, inode_post_create_tmpfile, struct mnt_idmap *idmap, + struct inode *inode) LSM_HOOK(int, 0, inode_link, struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) LSM_HOOK(int, 0, inode_unlink, struct inode *dir, struct dentry *dentry) diff --git a/include/linux/security.h b/include/linux/security.h index 5f595135c8f2..d77b717b5a45 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -344,6 +344,8 @@ int security_inode_init_security_anon(struct inode *inode, const struct qstr *name, const struct inode *context_inode); int security_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode); +void security_inode_post_create_tmpfile(struct mnt_idmap *idmap, + struct inode *inode); int security_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry); int security_inode_unlink(struct inode *dir, struct dentry *dentry); @@ -809,6 +811,10 @@ static inline int security_inode_create(struct inode *dir, return 0; } +static inline void +security_inode_post_create_tmpfile(struct mnt_idmap *idmap, struct inode *inode) +{ } + static inline int security_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) diff --git a/security/security.c b/security/security.c index b0203c488d17..a1bdf4859448 100644 --- a/security/security.c +++ b/security/security.c @@ -2013,6 +2013,21 @@ int security_inode_create(struct inode *dir, struct dentry *dentry, } EXPORT_SYMBOL_GPL(security_inode_create); +/** + * security_inode_post_create_tmpfile() - Update inode security of new tmpfile + * @idmap: idmap of the mount + * @inode: inode of the new tmpfile + * + * Update inode security data after a tmpfile has been created. + */ +void security_inode_post_create_tmpfile(struct mnt_idmap *idmap, + struct inode *inode) +{ + if (unlikely(IS_PRIVATE(inode))) + return; + call_void_hook(inode_post_create_tmpfile, idmap, inode); +} + /** * security_inode_link() - Check if creating a hard link is allowed * @old_dentry: existing file