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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/security/integrity/ima/ima_main.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/security/integrity/ima/ima_main.c')
-rw-r--r-- | kernel/security/integrity/ima/ima_main.c | 361 |
1 files changed, 361 insertions, 0 deletions
diff --git a/kernel/security/integrity/ima/ima_main.c b/kernel/security/integrity/ima/ima_main.c new file mode 100644 index 000000000..eeee00dce --- /dev/null +++ b/kernel/security/integrity/ima/ima_main.c @@ -0,0 +1,361 @@ +/* + * Copyright (C) 2005,2006,2007,2008 IBM Corporation + * + * Authors: + * Reiner Sailer <sailer@watson.ibm.com> + * Serge Hallyn <serue@us.ibm.com> + * Kylene Hall <kylene@us.ibm.com> + * Mimi Zohar <zohar@us.ibm.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation, version 2 of the + * License. + * + * File: ima_main.c + * implements the IMA hooks: ima_bprm_check, ima_file_mmap, + * and ima_file_check. + */ +#include <linux/module.h> +#include <linux/file.h> +#include <linux/binfmts.h> +#include <linux/mount.h> +#include <linux/mman.h> +#include <linux/slab.h> +#include <linux/xattr.h> +#include <linux/ima.h> +#include <crypto/hash_info.h> + +#include "ima.h" + +int ima_initialized; + +#ifdef CONFIG_IMA_APPRAISE +int ima_appraise = IMA_APPRAISE_ENFORCE; +#else +int ima_appraise; +#endif + +int ima_hash_algo = HASH_ALGO_SHA1; +static int hash_setup_done; + +static int __init hash_setup(char *str) +{ + struct ima_template_desc *template_desc = ima_template_desc_current(); + int i; + + if (hash_setup_done) + return 1; + + if (strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) { + if (strncmp(str, "sha1", 4) == 0) + ima_hash_algo = HASH_ALGO_SHA1; + else if (strncmp(str, "md5", 3) == 0) + ima_hash_algo = HASH_ALGO_MD5; + goto out; + } + + for (i = 0; i < HASH_ALGO__LAST; i++) { + if (strcmp(str, hash_algo_name[i]) == 0) { + ima_hash_algo = i; + break; + } + } +out: + hash_setup_done = 1; + return 1; +} +__setup("ima_hash=", hash_setup); + +/* + * ima_rdwr_violation_check + * + * Only invalidate the PCR for measured files: + * - Opening a file for write when already open for read, + * results in a time of measure, time of use (ToMToU) error. + * - Opening a file for read when already open for write, + * could result in a file measurement error. + * + */ +static void ima_rdwr_violation_check(struct file *file, + struct integrity_iint_cache *iint, + int must_measure, + char **pathbuf, + const char **pathname) +{ + struct inode *inode = file_inode(file); + fmode_t mode = file->f_mode; + bool send_tomtou = false, send_writers = false; + + if (mode & FMODE_WRITE) { + if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) { + if (!iint) + iint = integrity_iint_find(inode); + /* IMA_MEASURE is set from reader side */ + if (iint && (iint->flags & IMA_MEASURE)) + send_tomtou = true; + } + } else { + if ((atomic_read(&inode->i_writecount) > 0) && must_measure) + send_writers = true; + } + + if (!send_tomtou && !send_writers) + return; + + *pathname = ima_d_path(&file->f_path, pathbuf); + + if (send_tomtou) + ima_add_violation(file, *pathname, "invalid_pcr", "ToMToU"); + if (send_writers) + ima_add_violation(file, *pathname, + "invalid_pcr", "open_writers"); +} + +static void ima_check_last_writer(struct integrity_iint_cache *iint, + struct inode *inode, struct file *file) +{ + fmode_t mode = file->f_mode; + + if (!(mode & FMODE_WRITE)) + return; + + mutex_lock(&inode->i_mutex); + if (atomic_read(&inode->i_writecount) == 1) { + if ((iint->version != inode->i_version) || + (iint->flags & IMA_NEW_FILE)) { + iint->flags &= ~(IMA_DONE_MASK | IMA_NEW_FILE); + if (iint->flags & IMA_APPRAISE) + ima_update_xattr(iint, file); + } + } + mutex_unlock(&inode->i_mutex); +} + +/** + * ima_file_free - called on __fput() + * @file: pointer to file structure being freed + * + * Flag files that changed, based on i_version + */ +void ima_file_free(struct file *file) +{ + struct inode *inode = file_inode(file); + struct integrity_iint_cache *iint; + + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) + return; + + iint = integrity_iint_find(inode); + if (!iint) + return; + + ima_check_last_writer(iint, inode, file); +} + +static int process_measurement(struct file *file, int mask, int function, + int opened) +{ + struct inode *inode = file_inode(file); + struct integrity_iint_cache *iint = NULL; + struct ima_template_desc *template_desc; + char *pathbuf = NULL; + const char *pathname = NULL; + int rc = -ENOMEM, action, must_appraise; + struct evm_ima_xattr_data *xattr_value = NULL, **xattr_ptr = NULL; + int xattr_len = 0; + bool violation_check; + + if (!ima_policy_flag || !S_ISREG(inode->i_mode)) + return 0; + + /* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action + * bitmask based on the appraise/audit/measurement policy. + * Included is the appraise submask. + */ + action = ima_get_action(inode, mask, function); + violation_check = ((function == FILE_CHECK || function == MMAP_CHECK) && + (ima_policy_flag & IMA_MEASURE)); + if (!action && !violation_check) + return 0; + + must_appraise = action & IMA_APPRAISE; + + /* Is the appraise rule hook specific? */ + if (action & IMA_FILE_APPRAISE) + function = FILE_CHECK; + + mutex_lock(&inode->i_mutex); + + if (action) { + iint = integrity_inode_get(inode); + if (!iint) + goto out; + } + + if (violation_check) { + ima_rdwr_violation_check(file, iint, action & IMA_MEASURE, + &pathbuf, &pathname); + if (!action) { + rc = 0; + goto out_free; + } + } + + /* Determine if already appraised/measured based on bitmask + * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED, + * IMA_AUDIT, IMA_AUDITED) + */ + iint->flags |= action; + action &= IMA_DO_MASK; + action &= ~((iint->flags & IMA_DONE_MASK) >> 1); + + /* Nothing to do, just return existing appraised status */ + if (!action) { + if (must_appraise) + rc = ima_get_cache_status(iint, function); + goto out_digsig; + } + + template_desc = ima_template_desc_current(); + if ((action & IMA_APPRAISE_SUBMASK) || + strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0) + xattr_ptr = &xattr_value; + + rc = ima_collect_measurement(iint, file, xattr_ptr, &xattr_len); + if (rc != 0) { + if (file->f_flags & O_DIRECT) + rc = (iint->flags & IMA_PERMIT_DIRECTIO) ? 0 : -EACCES; + goto out_digsig; + } + + if (!pathname) /* ima_rdwr_violation possibly pre-fetched */ + pathname = ima_d_path(&file->f_path, &pathbuf); + + if (action & IMA_MEASURE) + ima_store_measurement(iint, file, pathname, + xattr_value, xattr_len); + if (action & IMA_APPRAISE_SUBMASK) + rc = ima_appraise_measurement(function, iint, file, pathname, + xattr_value, xattr_len, opened); + if (action & IMA_AUDIT) + ima_audit_measurement(iint, pathname); + +out_digsig: + if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG)) + rc = -EACCES; + kfree(xattr_value); +out_free: + if (pathbuf) + __putname(pathbuf); +out: + mutex_unlock(&inode->i_mutex); + if ((rc && must_appraise) && (ima_appraise & IMA_APPRAISE_ENFORCE)) + return -EACCES; + return 0; +} + +/** + * ima_file_mmap - based on policy, collect/store measurement. + * @file: pointer to the file to be measured (May be NULL) + * @prot: contains the protection that will be applied by the kernel. + * + * Measure files being mmapped executable based on the ima_must_measure() + * policy decision. + * + * On success return 0. On integrity appraisal error, assuming the file + * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. + */ +int ima_file_mmap(struct file *file, unsigned long prot) +{ + if (file && (prot & PROT_EXEC)) + return process_measurement(file, MAY_EXEC, MMAP_CHECK, 0); + return 0; +} + +/** + * ima_bprm_check - based on policy, collect/store measurement. + * @bprm: contains the linux_binprm structure + * + * The OS protects against an executable file, already open for write, + * from being executed in deny_write_access() and an executable file, + * already open for execute, from being modified in get_write_access(). + * So we can be certain that what we verify and measure here is actually + * what is being executed. + * + * On success return 0. On integrity appraisal error, assuming the file + * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. + */ +int ima_bprm_check(struct linux_binprm *bprm) +{ + return process_measurement(bprm->file, MAY_EXEC, BPRM_CHECK, 0); +} + +/** + * ima_path_check - based on policy, collect/store measurement. + * @file: pointer to the file to be measured + * @mask: contains MAY_READ, MAY_WRITE or MAY_EXECUTE + * + * Measure files based on the ima_must_measure() policy decision. + * + * On success return 0. On integrity appraisal error, assuming the file + * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. + */ +int ima_file_check(struct file *file, int mask, int opened) +{ + return process_measurement(file, + mask & (MAY_READ | MAY_WRITE | MAY_EXEC), + FILE_CHECK, opened); +} +EXPORT_SYMBOL_GPL(ima_file_check); + +/** + * ima_module_check - based on policy, collect/store/appraise measurement. + * @file: pointer to the file to be measured/appraised + * + * Measure/appraise kernel modules based on policy. + * + * On success return 0. On integrity appraisal error, assuming the file + * is in policy and IMA-appraisal is in enforcing mode, return -EACCES. + */ +int ima_module_check(struct file *file) +{ + if (!file) { +#ifndef CONFIG_MODULE_SIG_FORCE + if ((ima_appraise & IMA_APPRAISE_MODULES) && + (ima_appraise & IMA_APPRAISE_ENFORCE)) + return -EACCES; /* INTEGRITY_UNKNOWN */ +#endif + return 0; /* We rely on module signature checking */ + } + return process_measurement(file, MAY_EXEC, MODULE_CHECK, 0); +} + +int ima_fw_from_file(struct file *file, char *buf, size_t size) +{ + if (!file) { + if ((ima_appraise & IMA_APPRAISE_FIRMWARE) && + (ima_appraise & IMA_APPRAISE_ENFORCE)) + return -EACCES; /* INTEGRITY_UNKNOWN */ + return 0; + } + return process_measurement(file, MAY_EXEC, FIRMWARE_CHECK, 0); +} + +static int __init init_ima(void) +{ + int error; + + hash_setup(CONFIG_IMA_DEFAULT_HASH); + error = ima_init(); + if (!error) { + ima_initialized = 1; + ima_update_policy_flag(); + } + return error; +} + +late_initcall(init_ima); /* Start IMA after the TPM is available */ + +MODULE_DESCRIPTION("Integrity Measurement Architecture"); +MODULE_LICENSE("GPL"); |