From patchwork Thu Aug 31 10:41:13 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 13371201 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 3A5F2C83F01 for ; Thu, 31 Aug 2023 10:43:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244551AbjHaKnY (ORCPT ); Thu, 31 Aug 2023 06:43:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55944 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233470AbjHaKnY (ORCPT ); Thu, 31 Aug 2023 06:43:24 -0400 Received: from frasgout12.his.huawei.com (unknown [14.137.139.154]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8DC14E4A; Thu, 31 Aug 2023 03:43:15 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.18.147.227]) by frasgout12.his.huawei.com (SkyGuard) with ESMTP id 4Rby7V02Mkz9v7JW; Thu, 31 Aug 2023 18:28:54 +0800 (CST) Received: from huaweicloud.com (unknown [10.204.63.22]) by APP1 (Coremail) with SMTP id LxC2BwBXC7t9bvBkiGfdAQ--.39787S4; Thu, 31 Aug 2023 11:42:46 +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, zohar@linux.ibm.com, dmitry.kasatkin@gmail.com, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, dhowells@redhat.com, jarkko@kernel.org, stephen.smalley.work@gmail.com, eparis@parisplace.org, casey@schaufler-ca.com Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, keyrings@vger.kernel.org, selinux@vger.kernel.org, Roberto Sassu Subject: [PATCH v2 02/25] ima: Align ima_post_path_mknod() definition with LSM infrastructure Date: Thu, 31 Aug 2023 12:41:13 +0200 Message-Id: <20230831104136.903180-3-roberto.sassu@huaweicloud.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230831104136.903180-1-roberto.sassu@huaweicloud.com> References: <20230831104136.903180-1-roberto.sassu@huaweicloud.com> MIME-Version: 1.0 X-CM-TRANSID: LxC2BwBXC7t9bvBkiGfdAQ--.39787S4 X-Coremail-Antispam: 1UD129KBjvJXoWxGFyfuw43Ar4DXF4fXry3XFb_yoWrCF1kpF s5t3Z8Grn5Zry7uFy8AFW5Aa4FvasrXF45WFZYg34ayFnIqrn0qFsa9FWY9ryrKFWkCryx tF4UtrW5uw4UtFJanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUP2b4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUXw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV WxJr0_GcWl84ACjcxK6I8E87Iv67AKxVW8JVWxJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_ Cr1j6rxdM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMc Ij6xIIjxv20xvE14v26r106r15McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_ Jr0_Gr1lF7xvr2IYc2Ij64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1lc7CjxVAaw2AFwI 0_GFv_Wryl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG 67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MI IYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Xr0_Ar1lIxAIcVC0I7IYx2IY6xkF7I0E 14v26F4UJVW0owCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Gr 0_Cr1lIxAIcVC2z280aVCY1x0267AKxVWxJr0_GcJvcSsGvfC2KfnxnUUI43ZEXa7IU0jN t3UUUUU== X-CM-SenderInfo: purev21wro2thvvxqx5xdzvxpfor3voofrz/1tbiAQAGBF1jj5NcxgAAs7 X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: keyrings@vger.kernel.org From: Roberto Sassu Change ima_post_path_mknod() definition, so that it can be registered as implementation of the path_post_mknod hook. Since LSMs see a umask-stripped mode from security_path_mknod(), pass the same to ima_post_path_mknod() as well. Also, make sure that ima_post_path_mknod() is executed only if (mode & S_IFMT) is equal to zero or S_IFREG. Add this check to take into account the different placement of the path_post_mknod hook (to be introduced) in do_mknodat(). Since the new hook will be placed after the switch(), the check ensures that ima_post_path_mknod() is invoked as originally intended when it is registered as implementation of path_post_mknod. Signed-off-by: Roberto Sassu --- fs/namei.c | 9 ++++++--- include/linux/ima.h | 7 +++++-- security/integrity/ima/ima_main.c | 10 +++++++++- 3 files changed, 20 insertions(+), 6 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index e56ff39a79bc..c5e96f716f98 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -4024,6 +4024,7 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode, struct path path; int error; unsigned int lookup_flags = 0; + umode_t mode_stripped; error = may_mknod(mode); if (error) @@ -4034,8 +4035,9 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode, if (IS_ERR(dentry)) goto out1; - error = security_path_mknod(&path, dentry, - mode_strip_umask(path.dentry->d_inode, mode), dev); + mode_stripped = mode_strip_umask(path.dentry->d_inode, mode); + + error = security_path_mknod(&path, dentry, mode_stripped, dev); if (error) goto out2; @@ -4045,7 +4047,8 @@ static int do_mknodat(int dfd, struct filename *name, umode_t mode, error = vfs_create(idmap, path.dentry->d_inode, dentry, mode, true); if (!error) - ima_post_path_mknod(idmap, dentry); + ima_post_path_mknod(idmap, &path, dentry, + mode_stripped, dev); break; case S_IFCHR: case S_IFBLK: error = vfs_mknod(idmap, path.dentry->d_inode, diff --git a/include/linux/ima.h b/include/linux/ima.h index 910a2f11a906..179ce52013b2 100644 --- a/include/linux/ima.h +++ b/include/linux/ima.h @@ -32,7 +32,8 @@ extern int ima_read_file(struct file *file, enum kernel_read_file_id id, extern int ima_post_read_file(struct file *file, void *buf, loff_t size, enum kernel_read_file_id id); extern void ima_post_path_mknod(struct mnt_idmap *idmap, - struct dentry *dentry); + const struct path *dir, struct dentry *dentry, + umode_t mode, unsigned int dev); extern int ima_file_hash(struct file *file, char *buf, size_t buf_size); extern int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size); extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size); @@ -114,7 +115,9 @@ static inline int ima_post_read_file(struct file *file, void *buf, loff_t size, } static inline void ima_post_path_mknod(struct mnt_idmap *idmap, - struct dentry *dentry) + const struct path *dir, + struct dentry *dentry, + umode_t mode, unsigned int dev) { return; } diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c index 365db0e43d7c..76eba92d7f10 100644 --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -696,18 +696,26 @@ void ima_post_create_tmpfile(struct mnt_idmap *idmap, /** * ima_post_path_mknod - mark as a new inode * @idmap: idmap of the mount the inode was found from + * @dir: path structure of parent of the new file * @dentry: newly created dentry + * @mode: mode of the new file + * @dev: undecoded device number * * Mark files created via the mknodat syscall as new, so that the * file data can be written later. */ void ima_post_path_mknod(struct mnt_idmap *idmap, - struct dentry *dentry) + const struct path *dir, struct dentry *dentry, + umode_t mode, unsigned int dev) { struct integrity_iint_cache *iint; struct inode *inode = dentry->d_inode; int must_appraise; + /* See do_mknodat(), IMA is executed for case 0: and case S_IFREG: */ + if ((mode & S_IFMT) != 0 && (mode & S_IFMT) != S_IFREG) + return; + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) return;