Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753088AbdGYPtN (ORCPT ); Tue, 25 Jul 2017 11:49:13 -0400 Received: from lhrrgout.huawei.com ([194.213.3.17]:32203 "EHLO lhrrgout.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752761AbdGYPtK (ORCPT ); Tue, 25 Jul 2017 11:49:10 -0400 From: Roberto Sassu To: CC: , , , , Roberto Sassu Subject: [PATCH 03/12] ima: generalize policy file operations Date: Tue, 25 Jul 2017 17:44:14 +0200 Message-ID: <20170725154423.24845-4-roberto.sassu@huawei.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170725154423.24845-1-roberto.sassu@huawei.com> References: <20170725154423.24845-1-roberto.sassu@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.204.65.245] X-CFilter-Loop: Reflected X-Mirapoint-Virus-RAPID-Raw: score=unknown(0), refid=str=0001.0A020206.59776874.0258,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0, ip=0.0.0.0, so=2013-06-18 04:22:30, dmn=2013-03-21 17:37:32 X-Mirapoint-Loop-Id: 8e42a757a536e4fe5a84be6a21b42b7d Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3834 Lines: 121 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 upload and read provided data. Also, the new flag IMA_POLICY_BUSY has been defined specifically for the policy, as it might not be cleared at file release. This would prevent userspace applications from uploading files after a policy has been loaded. Signed-off-by: Roberto Sassu --- security/integrity/ima/ima_fs.c | 46 ++++++++++++++++++++++++++++------------- 1 file changed, 32 insertions(+), 14 deletions(-) diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c index e375206..f4199f2 100644 --- a/security/integrity/ima/ima_fs.c +++ b/security/integrity/ima/ima_fs.c @@ -384,6 +384,7 @@ static ssize_t ima_write_data(struct file *file, const char __user *buf, } enum ima_fs_flags { + IMA_POLICY_BUSY, IMA_FS_BUSY, }; @@ -399,22 +400,33 @@ 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) { + enum kernel_read_file_id file_id = ima_get_file_id(filp->f_path.dentry); + const struct seq_operations *seq_ops = NULL; + enum ima_fs_flags flag = IMA_FS_BUSY; + bool read_allowed = false; + + if (file_id == READING_POLICY) { + flag = IMA_POLICY_BUSY; +#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; } @@ -426,13 +438,19 @@ 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) { + enum kernel_read_file_id file_id = ima_get_file_id(file->f_path.dentry); const char *cause = valid_policy ? "completed" : "failed"; if ((file->f_flags & O_ACCMODE) == O_RDONLY) return seq_release(inode, file); + if (file_id != READING_POLICY) { + clear_bit(IMA_FS_BUSY, &ima_fs_flags); + return 0; + } + if (valid_policy && ima_check_policy() < 0) { cause = "failed"; valid_policy = 0; @@ -454,16 +472,16 @@ static int ima_release_policy(struct inode *inode, struct file *file) securityfs_remove(ima_policy); ima_policy = NULL; #else - clear_bit(IMA_FS_BUSY, &ima_fs_flags); + clear_bit(IMA_POLICY_BUSY, &ima_fs_flags); #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, }; @@ -502,7 +520,7 @@ 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; -- 2.9.3