From patchwork Fri Jun 14 17:55:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Roberto Sassu X-Patchwork-Id: 10996231 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 5B1DC14E5 for ; Fri, 14 Jun 2019 18:01:25 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 504EE2844E for ; Fri, 14 Jun 2019 18:01:25 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 448D628722; Fri, 14 Jun 2019 18:01:25 +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 D9C5528723 for ; Fri, 14 Jun 2019 18:01:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727070AbfFNSBY (ORCPT ); Fri, 14 Jun 2019 14:01:24 -0400 Received: from lhrrgout.huawei.com ([185.176.76.210]:33012 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726758AbfFNSBX (ORCPT ); Fri, 14 Jun 2019 14:01:23 -0400 Received: from lhreml702-cah.china.huawei.com (unknown [172.18.7.108]) by Forcepoint Email with ESMTP id 61CBBF107AFE943A80B4; Fri, 14 Jun 2019 19:01:22 +0100 (IST) Received: from roberto-HP-EliteDesk-800-G2-DM-65W.huawei.com (10.204.65.154) by smtpsuk.huawei.com (10.201.108.43) with Microsoft SMTP Server (TLS) id 14.3.408.0; Fri, 14 Jun 2019 19:01:14 +0100 From: Roberto Sassu To: , , CC: , , , , , , Roberto Sassu Subject: [PATCH v4 04/14] ima: generalize policy file operations Date: Fri, 14 Jun 2019 19:55:03 +0200 Message-ID: <20190614175513.27097-5-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20190614175513.27097-1-roberto.sassu@huawei.com> References: <20190614175513.27097-1-roberto.sassu@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.204.65.154] X-CFilter-Loop: Reflected Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP This patch renames ima_open_policy() and ima_release_policy() respectively to ima_open_data_upload() and ima_release_data_upload(). They will be used to implement file operations for interfaces allowing to load data from user space. A new flag (IMA_POLICY_BUSY) has been defined to prevent concurrent policy upload. Signed-off-by: Roberto Sassu --- security/integrity/ima/ima_fs.c | 58 ++++++++++++++++++++++++--------- 1 file changed, 43 insertions(+), 15 deletions(-) diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index 9a10b62e380f..c8bbc56f735e 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -386,9 +386,20 @@ static ssize_t ima_write_data(struct file *file, const char __user *buf, } enum ima_fs_flags { + IMA_POLICY_BUSY, IMA_FS_BUSY, }; +static enum ima_fs_flags ima_get_dentry_flag(struct dentry *dentry) +{ + enum ima_fs_flags flag = IMA_FS_BUSY; + + if (dentry == ima_policy) + flag = IMA_POLICY_BUSY; + + return flag; +} + static unsigned long ima_fs_flags; #ifdef CONFIG_IMA_READ_POLICY @@ -401,22 +412,32 @@ static const struct seq_operations ima_policy_seqops = { #endif /* - * ima_open_policy: sequentialize access to the policy file + * ima_open_data_upload: sequentialize access to the data upload interface */ -static int ima_open_policy(struct inode *inode, struct file *filp) +static int ima_open_data_upload(struct inode *inode, struct file *filp) { + struct dentry *dentry = file_dentry(filp); + const struct seq_operations *seq_ops = NULL; + enum ima_fs_flags flag = ima_get_dentry_flag(dentry); + bool read_allowed = false; + + if (dentry == ima_policy) { +#ifdef CONFIG_IMA_READ_POLICY + read_allowed = true; + seq_ops = &ima_policy_seqops; +#endif + } + if (!(filp->f_flags & O_WRONLY)) { -#ifndef CONFIG_IMA_READ_POLICY - return -EACCES; -#else + if (!read_allowed) + return -EACCES; if ((filp->f_flags & O_ACCMODE) != O_RDONLY) return -EACCES; if (!capable(CAP_SYS_ADMIN)) return -EPERM; - return seq_open(filp, &ima_policy_seqops); -#endif + return seq_open(filp, seq_ops); } - if (test_and_set_bit(IMA_FS_BUSY, &ima_fs_flags)) + if (test_and_set_bit(flag, &ima_fs_flags)) return -EBUSY; return 0; } @@ -428,13 +449,20 @@ static int ima_open_policy(struct inode *inode, struct file *filp) * point to the new policy rules, and remove the securityfs policy file, * assuming a valid policy. */ -static int ima_release_policy(struct inode *inode, struct file *file) +static int ima_release_data_upload(struct inode *inode, struct file *file) { + struct dentry *dentry = file_dentry(file); const char *cause = valid_policy ? "completed" : "failed"; + enum ima_fs_flags flag = ima_get_dentry_flag(dentry); if ((file->f_flags & O_ACCMODE) == O_RDONLY) return seq_release(inode, file); + if (dentry != ima_policy) { + clear_bit(flag, &ima_fs_flags); + return 0; + } + if (valid_policy && ima_check_policy() < 0) { cause = "failed"; valid_policy = 0; @@ -447,7 +475,7 @@ static int ima_release_policy(struct inode *inode, struct file *file) if (!valid_policy) { ima_delete_rules(); valid_policy = 1; - clear_bit(IMA_FS_BUSY, &ima_fs_flags); + clear_bit(flag, &ima_fs_flags); return 0; } @@ -456,18 +484,18 @@ static int ima_release_policy(struct inode *inode, struct file *file) securityfs_remove(ima_policy); ima_policy = NULL; #elif defined(CONFIG_IMA_WRITE_POLICY) - clear_bit(IMA_FS_BUSY, &ima_fs_flags); + clear_bit(flag, &ima_fs_flags); #elif defined(CONFIG_IMA_READ_POLICY) inode->i_mode &= ~S_IWUSR; #endif return 0; } -static const struct file_operations ima_measure_policy_ops = { - .open = ima_open_policy, +static const struct file_operations ima_data_upload_ops = { + .open = ima_open_data_upload, .write = ima_write_data, .read = seq_read, - .release = ima_release_policy, + .release = ima_release_data_upload, .llseek = generic_file_llseek, }; @@ -511,7 +539,7 @@ int __init ima_fs_init(void) ima_policy = securityfs_create_file("policy", POLICY_FILE_FLAGS, ima_dir, NULL, - &ima_measure_policy_ops); + &ima_data_upload_ops); if (IS_ERR(ima_policy)) goto out;