mirror of https://gitee.com/openkylin/linux.git
1107 lines
29 KiB
C
1107 lines
29 KiB
C
/*
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* Copyright (C) 2008 IBM Corporation
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* Author: Mimi Zohar <zohar@us.ibm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, version 2 of the License.
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*
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* ima_policy.c
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* - initialize default measure policy rules
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*
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*/
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#include <linux/module.h>
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#include <linux/list.h>
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#include <linux/fs.h>
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#include <linux/security.h>
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#include <linux/magic.h>
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#include <linux/parser.h>
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#include <linux/slab.h>
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#include <linux/rculist.h>
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#include <linux/genhd.h>
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#include <linux/seq_file.h>
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#include "ima.h"
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/* flags definitions */
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#define IMA_FUNC 0x0001
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#define IMA_MASK 0x0002
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#define IMA_FSMAGIC 0x0004
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#define IMA_UID 0x0008
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#define IMA_FOWNER 0x0010
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#define IMA_FSUUID 0x0020
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#define IMA_INMASK 0x0040
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#define IMA_EUID 0x0080
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#define IMA_PCR 0x0100
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#define UNKNOWN 0
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#define MEASURE 0x0001 /* same as IMA_MEASURE */
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#define DONT_MEASURE 0x0002
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#define APPRAISE 0x0004 /* same as IMA_APPRAISE */
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#define DONT_APPRAISE 0x0008
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#define AUDIT 0x0040
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#define INVALID_PCR(a) (((a) < 0) || \
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(a) >= (FIELD_SIZEOF(struct integrity_iint_cache, measured_pcrs) * 8))
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int ima_policy_flag;
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static int temp_ima_appraise;
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#define MAX_LSM_RULES 6
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enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
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LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
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};
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enum policy_types { ORIGINAL_TCB = 1, DEFAULT_TCB };
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struct ima_rule_entry {
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struct list_head list;
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int action;
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unsigned int flags;
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enum ima_hooks func;
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int mask;
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unsigned long fsmagic;
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u8 fsuuid[16];
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kuid_t uid;
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kuid_t fowner;
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int pcr;
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struct {
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void *rule; /* LSM file metadata specific */
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void *args_p; /* audit value */
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int type; /* audit type */
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} lsm[MAX_LSM_RULES];
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};
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/*
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* Without LSM specific knowledge, the default policy can only be
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* written in terms of .action, .func, .mask, .fsmagic, .uid, and .fowner
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*/
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/*
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* The minimum rule set to allow for full TCB coverage. Measures all files
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* opened or mmap for exec and everything read by root. Dangerous because
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* normal users can easily run the machine out of memory simply building
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* and running executables.
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*/
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static struct ima_rule_entry dont_measure_rules[] = {
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{.action = DONT_MEASURE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_MEASURE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_MEASURE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_MEASURE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_MEASURE, .fsmagic = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_MEASURE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_MEASURE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_MEASURE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_MEASURE, .fsmagic = CGROUP_SUPER_MAGIC,
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.flags = IMA_FSMAGIC},
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{.action = DONT_MEASURE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC}
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};
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static struct ima_rule_entry original_measurement_rules[] = {
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{.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC,
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.flags = IMA_FUNC | IMA_MASK},
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{.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC,
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.flags = IMA_FUNC | IMA_MASK},
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{.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
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.uid = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_MASK | IMA_UID},
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{.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
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{.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
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};
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static struct ima_rule_entry default_measurement_rules[] = {
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{.action = MEASURE, .func = MMAP_CHECK, .mask = MAY_EXEC,
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.flags = IMA_FUNC | IMA_MASK},
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{.action = MEASURE, .func = BPRM_CHECK, .mask = MAY_EXEC,
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.flags = IMA_FUNC | IMA_MASK},
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{.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
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.uid = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_INMASK | IMA_EUID},
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{.action = MEASURE, .func = FILE_CHECK, .mask = MAY_READ,
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.uid = GLOBAL_ROOT_UID, .flags = IMA_FUNC | IMA_INMASK | IMA_UID},
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{.action = MEASURE, .func = MODULE_CHECK, .flags = IMA_FUNC},
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{.action = MEASURE, .func = FIRMWARE_CHECK, .flags = IMA_FUNC},
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{.action = MEASURE, .func = POLICY_CHECK, .flags = IMA_FUNC},
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};
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static struct ima_rule_entry default_appraise_rules[] = {
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{.action = DONT_APPRAISE, .fsmagic = PROC_SUPER_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_APPRAISE, .fsmagic = SYSFS_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_APPRAISE, .fsmagic = DEBUGFS_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_APPRAISE, .fsmagic = TMPFS_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_APPRAISE, .fsmagic = RAMFS_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_APPRAISE, .fsmagic = DEVPTS_SUPER_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_APPRAISE, .fsmagic = BINFMTFS_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_APPRAISE, .fsmagic = SECURITYFS_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_APPRAISE, .fsmagic = SELINUX_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_APPRAISE, .fsmagic = NSFS_MAGIC, .flags = IMA_FSMAGIC},
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{.action = DONT_APPRAISE, .fsmagic = CGROUP_SUPER_MAGIC, .flags = IMA_FSMAGIC},
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#ifdef CONFIG_IMA_WRITE_POLICY
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{.action = APPRAISE, .func = POLICY_CHECK,
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.flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
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#endif
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#ifndef CONFIG_IMA_APPRAISE_SIGNED_INIT
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{.action = APPRAISE, .fowner = GLOBAL_ROOT_UID, .flags = IMA_FOWNER},
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#else
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/* force signature */
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{.action = APPRAISE, .fowner = GLOBAL_ROOT_UID,
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.flags = IMA_FOWNER | IMA_DIGSIG_REQUIRED},
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#endif
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};
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static LIST_HEAD(ima_default_rules);
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static LIST_HEAD(ima_policy_rules);
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static LIST_HEAD(ima_temp_rules);
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static struct list_head *ima_rules;
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static int ima_policy __initdata;
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static int __init default_measure_policy_setup(char *str)
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{
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if (ima_policy)
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return 1;
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ima_policy = ORIGINAL_TCB;
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return 1;
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}
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__setup("ima_tcb", default_measure_policy_setup);
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static int __init policy_setup(char *str)
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{
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if (ima_policy)
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return 1;
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if (strcmp(str, "tcb") == 0)
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ima_policy = DEFAULT_TCB;
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return 1;
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}
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__setup("ima_policy=", policy_setup);
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static bool ima_use_appraise_tcb __initdata;
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static int __init default_appraise_policy_setup(char *str)
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{
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ima_use_appraise_tcb = 1;
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return 1;
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}
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__setup("ima_appraise_tcb", default_appraise_policy_setup);
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/*
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* The LSM policy can be reloaded, leaving the IMA LSM based rules referring
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* to the old, stale LSM policy. Update the IMA LSM based rules to reflect
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* the reloaded LSM policy. We assume the rules still exist; and BUG_ON() if
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* they don't.
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*/
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static void ima_lsm_update_rules(void)
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{
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struct ima_rule_entry *entry;
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int result;
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int i;
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list_for_each_entry(entry, &ima_policy_rules, list) {
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for (i = 0; i < MAX_LSM_RULES; i++) {
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if (!entry->lsm[i].rule)
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continue;
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result = security_filter_rule_init(entry->lsm[i].type,
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Audit_equal,
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entry->lsm[i].args_p,
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&entry->lsm[i].rule);
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BUG_ON(!entry->lsm[i].rule);
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}
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}
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}
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/**
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* ima_match_rules - determine whether an inode matches the measure rule.
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* @rule: a pointer to a rule
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* @inode: a pointer to an inode
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* @func: LIM hook identifier
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* @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
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*
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* Returns true on rule match, false on failure.
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*/
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static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
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enum ima_hooks func, int mask)
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{
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struct task_struct *tsk = current;
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const struct cred *cred = current_cred();
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int i;
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if ((rule->flags & IMA_FUNC) &&
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(rule->func != func && func != POST_SETATTR))
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return false;
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if ((rule->flags & IMA_MASK) &&
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(rule->mask != mask && func != POST_SETATTR))
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return false;
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if ((rule->flags & IMA_INMASK) &&
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(!(rule->mask & mask) && func != POST_SETATTR))
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return false;
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if ((rule->flags & IMA_FSMAGIC)
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&& rule->fsmagic != inode->i_sb->s_magic)
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return false;
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if ((rule->flags & IMA_FSUUID) &&
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memcmp(rule->fsuuid, inode->i_sb->s_uuid, sizeof(rule->fsuuid)))
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return false;
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if ((rule->flags & IMA_UID) && !uid_eq(rule->uid, cred->uid))
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return false;
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if (rule->flags & IMA_EUID) {
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if (has_capability_noaudit(current, CAP_SETUID)) {
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if (!uid_eq(rule->uid, cred->euid)
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&& !uid_eq(rule->uid, cred->suid)
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&& !uid_eq(rule->uid, cred->uid))
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return false;
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} else if (!uid_eq(rule->uid, cred->euid))
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return false;
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}
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if ((rule->flags & IMA_FOWNER) && !uid_eq(rule->fowner, inode->i_uid))
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return false;
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for (i = 0; i < MAX_LSM_RULES; i++) {
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int rc = 0;
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u32 osid, sid;
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int retried = 0;
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if (!rule->lsm[i].rule)
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continue;
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retry:
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switch (i) {
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case LSM_OBJ_USER:
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case LSM_OBJ_ROLE:
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case LSM_OBJ_TYPE:
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security_inode_getsecid(inode, &osid);
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rc = security_filter_rule_match(osid,
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rule->lsm[i].type,
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Audit_equal,
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rule->lsm[i].rule,
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NULL);
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break;
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case LSM_SUBJ_USER:
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case LSM_SUBJ_ROLE:
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case LSM_SUBJ_TYPE:
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security_task_getsecid(tsk, &sid);
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rc = security_filter_rule_match(sid,
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rule->lsm[i].type,
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Audit_equal,
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rule->lsm[i].rule,
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NULL);
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default:
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break;
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}
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if ((rc < 0) && (!retried)) {
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retried = 1;
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ima_lsm_update_rules();
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goto retry;
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}
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if (!rc)
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return false;
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}
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return true;
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}
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/*
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* In addition to knowing that we need to appraise the file in general,
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* we need to differentiate between calling hooks, for hook specific rules.
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*/
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static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
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{
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if (!(rule->flags & IMA_FUNC))
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return IMA_FILE_APPRAISE;
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switch (func) {
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case MMAP_CHECK:
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return IMA_MMAP_APPRAISE;
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case BPRM_CHECK:
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return IMA_BPRM_APPRAISE;
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case FILE_CHECK:
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case POST_SETATTR:
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return IMA_FILE_APPRAISE;
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case MODULE_CHECK ... MAX_CHECK - 1:
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default:
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return IMA_READ_APPRAISE;
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}
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}
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/**
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* ima_match_policy - decision based on LSM and other conditions
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* @inode: pointer to an inode for which the policy decision is being made
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* @func: IMA hook identifier
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* @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
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* @pcr: set the pcr to extend
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*
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* Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
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* conditions.
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*
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* Since the IMA policy may be updated multiple times we need to lock the
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* list when walking it. Reads are many orders of magnitude more numerous
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* than writes so ima_match_policy() is classical RCU candidate.
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*/
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int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask,
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int flags, int *pcr)
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{
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struct ima_rule_entry *entry;
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int action = 0, actmask = flags | (flags << 1);
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rcu_read_lock();
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list_for_each_entry_rcu(entry, ima_rules, list) {
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if (!(entry->action & actmask))
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continue;
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if (!ima_match_rules(entry, inode, func, mask))
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continue;
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action |= entry->flags & IMA_ACTION_FLAGS;
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action |= entry->action & IMA_DO_MASK;
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if (entry->action & IMA_APPRAISE)
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action |= get_subaction(entry, func);
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if (entry->action & IMA_DO_MASK)
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actmask &= ~(entry->action | entry->action << 1);
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else
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actmask &= ~(entry->action | entry->action >> 1);
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if ((pcr) && (entry->flags & IMA_PCR))
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*pcr = entry->pcr;
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if (!actmask)
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break;
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}
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rcu_read_unlock();
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return action;
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}
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/*
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* Initialize the ima_policy_flag variable based on the currently
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* loaded policy. Based on this flag, the decision to short circuit
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* out of a function or not call the function in the first place
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* can be made earlier.
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*/
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void ima_update_policy_flag(void)
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{
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struct ima_rule_entry *entry;
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list_for_each_entry(entry, ima_rules, list) {
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if (entry->action & IMA_DO_MASK)
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ima_policy_flag |= entry->action;
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}
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ima_appraise |= temp_ima_appraise;
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if (!ima_appraise)
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ima_policy_flag &= ~IMA_APPRAISE;
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}
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/**
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* ima_init_policy - initialize the default measure rules.
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*
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* ima_rules points to either the ima_default_rules or the
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* the new ima_policy_rules.
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*/
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void __init ima_init_policy(void)
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{
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int i, measure_entries, appraise_entries;
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/* if !ima_policy set entries = 0 so we load NO default rules */
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measure_entries = ima_policy ? ARRAY_SIZE(dont_measure_rules) : 0;
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appraise_entries = ima_use_appraise_tcb ?
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ARRAY_SIZE(default_appraise_rules) : 0;
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for (i = 0; i < measure_entries; i++)
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list_add_tail(&dont_measure_rules[i].list, &ima_default_rules);
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switch (ima_policy) {
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case ORIGINAL_TCB:
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for (i = 0; i < ARRAY_SIZE(original_measurement_rules); i++)
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list_add_tail(&original_measurement_rules[i].list,
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&ima_default_rules);
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break;
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case DEFAULT_TCB:
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for (i = 0; i < ARRAY_SIZE(default_measurement_rules); i++)
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list_add_tail(&default_measurement_rules[i].list,
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&ima_default_rules);
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default:
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break;
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}
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for (i = 0; i < appraise_entries; i++) {
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list_add_tail(&default_appraise_rules[i].list,
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&ima_default_rules);
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if (default_appraise_rules[i].func == POLICY_CHECK)
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temp_ima_appraise |= IMA_APPRAISE_POLICY;
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}
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ima_rules = &ima_default_rules;
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ima_update_policy_flag();
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}
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/* Make sure we have a valid policy, at least containing some rules. */
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int ima_check_policy(void)
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{
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if (list_empty(&ima_temp_rules))
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return -EINVAL;
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return 0;
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}
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|
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/**
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* ima_update_policy - update default_rules with new measure rules
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*
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* Called on file .release to update the default rules with a complete new
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* policy. What we do here is to splice ima_policy_rules and ima_temp_rules so
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* they make a queue. The policy may be updated multiple times and this is the
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* RCU updater.
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*
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* Policy rules are never deleted so ima_policy_flag gets zeroed only once when
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* we switch from the default policy to user defined.
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*/
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void ima_update_policy(void)
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{
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struct list_head *first, *last, *policy;
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|
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/* append current policy with the new rules */
|
|
first = (&ima_temp_rules)->next;
|
|
last = (&ima_temp_rules)->prev;
|
|
policy = &ima_policy_rules;
|
|
|
|
synchronize_rcu();
|
|
|
|
last->next = policy;
|
|
rcu_assign_pointer(list_next_rcu(policy->prev), first);
|
|
first->prev = policy->prev;
|
|
policy->prev = last;
|
|
|
|
/* prepare for the next policy rules addition */
|
|
INIT_LIST_HEAD(&ima_temp_rules);
|
|
|
|
if (ima_rules != policy) {
|
|
ima_policy_flag = 0;
|
|
ima_rules = policy;
|
|
}
|
|
ima_update_policy_flag();
|
|
}
|
|
|
|
enum {
|
|
Opt_err = -1,
|
|
Opt_measure = 1, Opt_dont_measure,
|
|
Opt_appraise, Opt_dont_appraise,
|
|
Opt_audit,
|
|
Opt_obj_user, Opt_obj_role, Opt_obj_type,
|
|
Opt_subj_user, Opt_subj_role, Opt_subj_type,
|
|
Opt_func, Opt_mask, Opt_fsmagic,
|
|
Opt_fsuuid, Opt_uid, Opt_euid, Opt_fowner,
|
|
Opt_appraise_type, Opt_permit_directio,
|
|
Opt_pcr
|
|
};
|
|
|
|
static match_table_t policy_tokens = {
|
|
{Opt_measure, "measure"},
|
|
{Opt_dont_measure, "dont_measure"},
|
|
{Opt_appraise, "appraise"},
|
|
{Opt_dont_appraise, "dont_appraise"},
|
|
{Opt_audit, "audit"},
|
|
{Opt_obj_user, "obj_user=%s"},
|
|
{Opt_obj_role, "obj_role=%s"},
|
|
{Opt_obj_type, "obj_type=%s"},
|
|
{Opt_subj_user, "subj_user=%s"},
|
|
{Opt_subj_role, "subj_role=%s"},
|
|
{Opt_subj_type, "subj_type=%s"},
|
|
{Opt_func, "func=%s"},
|
|
{Opt_mask, "mask=%s"},
|
|
{Opt_fsmagic, "fsmagic=%s"},
|
|
{Opt_fsuuid, "fsuuid=%s"},
|
|
{Opt_uid, "uid=%s"},
|
|
{Opt_euid, "euid=%s"},
|
|
{Opt_fowner, "fowner=%s"},
|
|
{Opt_appraise_type, "appraise_type=%s"},
|
|
{Opt_permit_directio, "permit_directio"},
|
|
{Opt_pcr, "pcr=%s"},
|
|
{Opt_err, NULL}
|
|
};
|
|
|
|
static int ima_lsm_rule_init(struct ima_rule_entry *entry,
|
|
substring_t *args, int lsm_rule, int audit_type)
|
|
{
|
|
int result;
|
|
|
|
if (entry->lsm[lsm_rule].rule)
|
|
return -EINVAL;
|
|
|
|
entry->lsm[lsm_rule].args_p = match_strdup(args);
|
|
if (!entry->lsm[lsm_rule].args_p)
|
|
return -ENOMEM;
|
|
|
|
entry->lsm[lsm_rule].type = audit_type;
|
|
result = security_filter_rule_init(entry->lsm[lsm_rule].type,
|
|
Audit_equal,
|
|
entry->lsm[lsm_rule].args_p,
|
|
&entry->lsm[lsm_rule].rule);
|
|
if (!entry->lsm[lsm_rule].rule) {
|
|
kfree(entry->lsm[lsm_rule].args_p);
|
|
return -EINVAL;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
static void ima_log_string(struct audit_buffer *ab, char *key, char *value)
|
|
{
|
|
audit_log_format(ab, "%s=", key);
|
|
audit_log_untrustedstring(ab, value);
|
|
audit_log_format(ab, " ");
|
|
}
|
|
|
|
static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
|
|
{
|
|
struct audit_buffer *ab;
|
|
char *from;
|
|
char *p;
|
|
int result = 0;
|
|
|
|
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE);
|
|
|
|
entry->uid = INVALID_UID;
|
|
entry->fowner = INVALID_UID;
|
|
entry->action = UNKNOWN;
|
|
while ((p = strsep(&rule, " \t")) != NULL) {
|
|
substring_t args[MAX_OPT_ARGS];
|
|
int token;
|
|
unsigned long lnum;
|
|
|
|
if (result < 0)
|
|
break;
|
|
if ((*p == '\0') || (*p == ' ') || (*p == '\t'))
|
|
continue;
|
|
token = match_token(p, policy_tokens, args);
|
|
switch (token) {
|
|
case Opt_measure:
|
|
ima_log_string(ab, "action", "measure");
|
|
|
|
if (entry->action != UNKNOWN)
|
|
result = -EINVAL;
|
|
|
|
entry->action = MEASURE;
|
|
break;
|
|
case Opt_dont_measure:
|
|
ima_log_string(ab, "action", "dont_measure");
|
|
|
|
if (entry->action != UNKNOWN)
|
|
result = -EINVAL;
|
|
|
|
entry->action = DONT_MEASURE;
|
|
break;
|
|
case Opt_appraise:
|
|
ima_log_string(ab, "action", "appraise");
|
|
|
|
if (entry->action != UNKNOWN)
|
|
result = -EINVAL;
|
|
|
|
entry->action = APPRAISE;
|
|
break;
|
|
case Opt_dont_appraise:
|
|
ima_log_string(ab, "action", "dont_appraise");
|
|
|
|
if (entry->action != UNKNOWN)
|
|
result = -EINVAL;
|
|
|
|
entry->action = DONT_APPRAISE;
|
|
break;
|
|
case Opt_audit:
|
|
ima_log_string(ab, "action", "audit");
|
|
|
|
if (entry->action != UNKNOWN)
|
|
result = -EINVAL;
|
|
|
|
entry->action = AUDIT;
|
|
break;
|
|
case Opt_func:
|
|
ima_log_string(ab, "func", args[0].from);
|
|
|
|
if (entry->func)
|
|
result = -EINVAL;
|
|
|
|
if (strcmp(args[0].from, "FILE_CHECK") == 0)
|
|
entry->func = FILE_CHECK;
|
|
/* PATH_CHECK is for backwards compat */
|
|
else if (strcmp(args[0].from, "PATH_CHECK") == 0)
|
|
entry->func = FILE_CHECK;
|
|
else if (strcmp(args[0].from, "MODULE_CHECK") == 0)
|
|
entry->func = MODULE_CHECK;
|
|
else if (strcmp(args[0].from, "FIRMWARE_CHECK") == 0)
|
|
entry->func = FIRMWARE_CHECK;
|
|
else if ((strcmp(args[0].from, "FILE_MMAP") == 0)
|
|
|| (strcmp(args[0].from, "MMAP_CHECK") == 0))
|
|
entry->func = MMAP_CHECK;
|
|
else if (strcmp(args[0].from, "BPRM_CHECK") == 0)
|
|
entry->func = BPRM_CHECK;
|
|
else if (strcmp(args[0].from, "KEXEC_KERNEL_CHECK") ==
|
|
0)
|
|
entry->func = KEXEC_KERNEL_CHECK;
|
|
else if (strcmp(args[0].from, "KEXEC_INITRAMFS_CHECK")
|
|
== 0)
|
|
entry->func = KEXEC_INITRAMFS_CHECK;
|
|
else if (strcmp(args[0].from, "POLICY_CHECK") == 0)
|
|
entry->func = POLICY_CHECK;
|
|
else
|
|
result = -EINVAL;
|
|
if (!result)
|
|
entry->flags |= IMA_FUNC;
|
|
break;
|
|
case Opt_mask:
|
|
ima_log_string(ab, "mask", args[0].from);
|
|
|
|
if (entry->mask)
|
|
result = -EINVAL;
|
|
|
|
from = args[0].from;
|
|
if (*from == '^')
|
|
from++;
|
|
|
|
if ((strcmp(from, "MAY_EXEC")) == 0)
|
|
entry->mask = MAY_EXEC;
|
|
else if (strcmp(from, "MAY_WRITE") == 0)
|
|
entry->mask = MAY_WRITE;
|
|
else if (strcmp(from, "MAY_READ") == 0)
|
|
entry->mask = MAY_READ;
|
|
else if (strcmp(from, "MAY_APPEND") == 0)
|
|
entry->mask = MAY_APPEND;
|
|
else
|
|
result = -EINVAL;
|
|
if (!result)
|
|
entry->flags |= (*args[0].from == '^')
|
|
? IMA_INMASK : IMA_MASK;
|
|
break;
|
|
case Opt_fsmagic:
|
|
ima_log_string(ab, "fsmagic", args[0].from);
|
|
|
|
if (entry->fsmagic) {
|
|
result = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
result = kstrtoul(args[0].from, 16, &entry->fsmagic);
|
|
if (!result)
|
|
entry->flags |= IMA_FSMAGIC;
|
|
break;
|
|
case Opt_fsuuid:
|
|
ima_log_string(ab, "fsuuid", args[0].from);
|
|
|
|
if (memchr_inv(entry->fsuuid, 0x00,
|
|
sizeof(entry->fsuuid))) {
|
|
result = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
result = blk_part_pack_uuid(args[0].from,
|
|
entry->fsuuid);
|
|
if (!result)
|
|
entry->flags |= IMA_FSUUID;
|
|
break;
|
|
case Opt_uid:
|
|
ima_log_string(ab, "uid", args[0].from);
|
|
case Opt_euid:
|
|
if (token == Opt_euid)
|
|
ima_log_string(ab, "euid", args[0].from);
|
|
|
|
if (uid_valid(entry->uid)) {
|
|
result = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
result = kstrtoul(args[0].from, 10, &lnum);
|
|
if (!result) {
|
|
entry->uid = make_kuid(current_user_ns(),
|
|
(uid_t) lnum);
|
|
if (!uid_valid(entry->uid) ||
|
|
(uid_t)lnum != lnum)
|
|
result = -EINVAL;
|
|
else
|
|
entry->flags |= (token == Opt_uid)
|
|
? IMA_UID : IMA_EUID;
|
|
}
|
|
break;
|
|
case Opt_fowner:
|
|
ima_log_string(ab, "fowner", args[0].from);
|
|
|
|
if (uid_valid(entry->fowner)) {
|
|
result = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
result = kstrtoul(args[0].from, 10, &lnum);
|
|
if (!result) {
|
|
entry->fowner = make_kuid(current_user_ns(), (uid_t)lnum);
|
|
if (!uid_valid(entry->fowner) || (((uid_t)lnum) != lnum))
|
|
result = -EINVAL;
|
|
else
|
|
entry->flags |= IMA_FOWNER;
|
|
}
|
|
break;
|
|
case Opt_obj_user:
|
|
ima_log_string(ab, "obj_user", args[0].from);
|
|
result = ima_lsm_rule_init(entry, args,
|
|
LSM_OBJ_USER,
|
|
AUDIT_OBJ_USER);
|
|
break;
|
|
case Opt_obj_role:
|
|
ima_log_string(ab, "obj_role", args[0].from);
|
|
result = ima_lsm_rule_init(entry, args,
|
|
LSM_OBJ_ROLE,
|
|
AUDIT_OBJ_ROLE);
|
|
break;
|
|
case Opt_obj_type:
|
|
ima_log_string(ab, "obj_type", args[0].from);
|
|
result = ima_lsm_rule_init(entry, args,
|
|
LSM_OBJ_TYPE,
|
|
AUDIT_OBJ_TYPE);
|
|
break;
|
|
case Opt_subj_user:
|
|
ima_log_string(ab, "subj_user", args[0].from);
|
|
result = ima_lsm_rule_init(entry, args,
|
|
LSM_SUBJ_USER,
|
|
AUDIT_SUBJ_USER);
|
|
break;
|
|
case Opt_subj_role:
|
|
ima_log_string(ab, "subj_role", args[0].from);
|
|
result = ima_lsm_rule_init(entry, args,
|
|
LSM_SUBJ_ROLE,
|
|
AUDIT_SUBJ_ROLE);
|
|
break;
|
|
case Opt_subj_type:
|
|
ima_log_string(ab, "subj_type", args[0].from);
|
|
result = ima_lsm_rule_init(entry, args,
|
|
LSM_SUBJ_TYPE,
|
|
AUDIT_SUBJ_TYPE);
|
|
break;
|
|
case Opt_appraise_type:
|
|
if (entry->action != APPRAISE) {
|
|
result = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
ima_log_string(ab, "appraise_type", args[0].from);
|
|
if ((strcmp(args[0].from, "imasig")) == 0)
|
|
entry->flags |= IMA_DIGSIG_REQUIRED;
|
|
else
|
|
result = -EINVAL;
|
|
break;
|
|
case Opt_permit_directio:
|
|
entry->flags |= IMA_PERMIT_DIRECTIO;
|
|
break;
|
|
case Opt_pcr:
|
|
if (entry->action != MEASURE) {
|
|
result = -EINVAL;
|
|
break;
|
|
}
|
|
ima_log_string(ab, "pcr", args[0].from);
|
|
|
|
result = kstrtoint(args[0].from, 10, &entry->pcr);
|
|
if (result || INVALID_PCR(entry->pcr))
|
|
result = -EINVAL;
|
|
else
|
|
entry->flags |= IMA_PCR;
|
|
|
|
break;
|
|
case Opt_err:
|
|
ima_log_string(ab, "UNKNOWN", p);
|
|
result = -EINVAL;
|
|
break;
|
|
}
|
|
}
|
|
if (!result && (entry->action == UNKNOWN))
|
|
result = -EINVAL;
|
|
else if (entry->func == MODULE_CHECK)
|
|
temp_ima_appraise |= IMA_APPRAISE_MODULES;
|
|
else if (entry->func == FIRMWARE_CHECK)
|
|
temp_ima_appraise |= IMA_APPRAISE_FIRMWARE;
|
|
else if (entry->func == POLICY_CHECK)
|
|
temp_ima_appraise |= IMA_APPRAISE_POLICY;
|
|
audit_log_format(ab, "res=%d", !result);
|
|
audit_log_end(ab);
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* ima_parse_add_rule - add a rule to ima_policy_rules
|
|
* @rule - ima measurement policy rule
|
|
*
|
|
* Avoid locking by allowing just one writer at a time in ima_write_policy()
|
|
* Returns the length of the rule parsed, an error code on failure
|
|
*/
|
|
ssize_t ima_parse_add_rule(char *rule)
|
|
{
|
|
static const char op[] = "update_policy";
|
|
char *p;
|
|
struct ima_rule_entry *entry;
|
|
ssize_t result, len;
|
|
int audit_info = 0;
|
|
|
|
p = strsep(&rule, "\n");
|
|
len = strlen(p) + 1;
|
|
p += strspn(p, " \t");
|
|
|
|
if (*p == '#' || *p == '\0')
|
|
return len;
|
|
|
|
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
|
|
if (!entry) {
|
|
integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
|
|
NULL, op, "-ENOMEM", -ENOMEM, audit_info);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
INIT_LIST_HEAD(&entry->list);
|
|
|
|
result = ima_parse_rule(p, entry);
|
|
if (result) {
|
|
kfree(entry);
|
|
integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
|
|
NULL, op, "invalid-policy", result,
|
|
audit_info);
|
|
return result;
|
|
}
|
|
|
|
list_add_tail(&entry->list, &ima_temp_rules);
|
|
|
|
return len;
|
|
}
|
|
|
|
/**
|
|
* ima_delete_rules() called to cleanup invalid in-flight policy.
|
|
* We don't need locking as we operate on the temp list, which is
|
|
* different from the active one. There is also only one user of
|
|
* ima_delete_rules() at a time.
|
|
*/
|
|
void ima_delete_rules(void)
|
|
{
|
|
struct ima_rule_entry *entry, *tmp;
|
|
int i;
|
|
|
|
temp_ima_appraise = 0;
|
|
list_for_each_entry_safe(entry, tmp, &ima_temp_rules, list) {
|
|
for (i = 0; i < MAX_LSM_RULES; i++)
|
|
kfree(entry->lsm[i].args_p);
|
|
|
|
list_del(&entry->list);
|
|
kfree(entry);
|
|
}
|
|
}
|
|
|
|
#ifdef CONFIG_IMA_READ_POLICY
|
|
enum {
|
|
mask_exec = 0, mask_write, mask_read, mask_append
|
|
};
|
|
|
|
static char *mask_tokens[] = {
|
|
"MAY_EXEC",
|
|
"MAY_WRITE",
|
|
"MAY_READ",
|
|
"MAY_APPEND"
|
|
};
|
|
|
|
enum {
|
|
func_file = 0, func_mmap, func_bprm,
|
|
func_module, func_firmware, func_post,
|
|
func_kexec_kernel, func_kexec_initramfs,
|
|
func_policy
|
|
};
|
|
|
|
static char *func_tokens[] = {
|
|
"FILE_CHECK",
|
|
"MMAP_CHECK",
|
|
"BPRM_CHECK",
|
|
"MODULE_CHECK",
|
|
"FIRMWARE_CHECK",
|
|
"POST_SETATTR",
|
|
"KEXEC_KERNEL_CHECK",
|
|
"KEXEC_INITRAMFS_CHECK",
|
|
"POLICY_CHECK"
|
|
};
|
|
|
|
void *ima_policy_start(struct seq_file *m, loff_t *pos)
|
|
{
|
|
loff_t l = *pos;
|
|
struct ima_rule_entry *entry;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(entry, ima_rules, list) {
|
|
if (!l--) {
|
|
rcu_read_unlock();
|
|
return entry;
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
return NULL;
|
|
}
|
|
|
|
void *ima_policy_next(struct seq_file *m, void *v, loff_t *pos)
|
|
{
|
|
struct ima_rule_entry *entry = v;
|
|
|
|
rcu_read_lock();
|
|
entry = list_entry_rcu(entry->list.next, struct ima_rule_entry, list);
|
|
rcu_read_unlock();
|
|
(*pos)++;
|
|
|
|
return (&entry->list == ima_rules) ? NULL : entry;
|
|
}
|
|
|
|
void ima_policy_stop(struct seq_file *m, void *v)
|
|
{
|
|
}
|
|
|
|
#define pt(token) policy_tokens[token + Opt_err].pattern
|
|
#define mt(token) mask_tokens[token]
|
|
#define ft(token) func_tokens[token]
|
|
|
|
/*
|
|
* policy_func_show - display the ima_hooks policy rule
|
|
*/
|
|
static void policy_func_show(struct seq_file *m, enum ima_hooks func)
|
|
{
|
|
char tbuf[64] = {0,};
|
|
|
|
switch (func) {
|
|
case FILE_CHECK:
|
|
seq_printf(m, pt(Opt_func), ft(func_file));
|
|
break;
|
|
case MMAP_CHECK:
|
|
seq_printf(m, pt(Opt_func), ft(func_mmap));
|
|
break;
|
|
case BPRM_CHECK:
|
|
seq_printf(m, pt(Opt_func), ft(func_bprm));
|
|
break;
|
|
case MODULE_CHECK:
|
|
seq_printf(m, pt(Opt_func), ft(func_module));
|
|
break;
|
|
case FIRMWARE_CHECK:
|
|
seq_printf(m, pt(Opt_func), ft(func_firmware));
|
|
break;
|
|
case POST_SETATTR:
|
|
seq_printf(m, pt(Opt_func), ft(func_post));
|
|
break;
|
|
case KEXEC_KERNEL_CHECK:
|
|
seq_printf(m, pt(Opt_func), ft(func_kexec_kernel));
|
|
break;
|
|
case KEXEC_INITRAMFS_CHECK:
|
|
seq_printf(m, pt(Opt_func), ft(func_kexec_initramfs));
|
|
break;
|
|
case POLICY_CHECK:
|
|
seq_printf(m, pt(Opt_func), ft(func_policy));
|
|
break;
|
|
default:
|
|
snprintf(tbuf, sizeof(tbuf), "%d", func);
|
|
seq_printf(m, pt(Opt_func), tbuf);
|
|
break;
|
|
}
|
|
seq_puts(m, " ");
|
|
}
|
|
|
|
int ima_policy_show(struct seq_file *m, void *v)
|
|
{
|
|
struct ima_rule_entry *entry = v;
|
|
int i;
|
|
char tbuf[64] = {0,};
|
|
|
|
rcu_read_lock();
|
|
|
|
if (entry->action & MEASURE)
|
|
seq_puts(m, pt(Opt_measure));
|
|
if (entry->action & DONT_MEASURE)
|
|
seq_puts(m, pt(Opt_dont_measure));
|
|
if (entry->action & APPRAISE)
|
|
seq_puts(m, pt(Opt_appraise));
|
|
if (entry->action & DONT_APPRAISE)
|
|
seq_puts(m, pt(Opt_dont_appraise));
|
|
if (entry->action & AUDIT)
|
|
seq_puts(m, pt(Opt_audit));
|
|
|
|
seq_puts(m, " ");
|
|
|
|
if (entry->flags & IMA_FUNC)
|
|
policy_func_show(m, entry->func);
|
|
|
|
if (entry->flags & IMA_MASK) {
|
|
if (entry->mask & MAY_EXEC)
|
|
seq_printf(m, pt(Opt_mask), mt(mask_exec));
|
|
if (entry->mask & MAY_WRITE)
|
|
seq_printf(m, pt(Opt_mask), mt(mask_write));
|
|
if (entry->mask & MAY_READ)
|
|
seq_printf(m, pt(Opt_mask), mt(mask_read));
|
|
if (entry->mask & MAY_APPEND)
|
|
seq_printf(m, pt(Opt_mask), mt(mask_append));
|
|
seq_puts(m, " ");
|
|
}
|
|
|
|
if (entry->flags & IMA_FSMAGIC) {
|
|
snprintf(tbuf, sizeof(tbuf), "0x%lx", entry->fsmagic);
|
|
seq_printf(m, pt(Opt_fsmagic), tbuf);
|
|
seq_puts(m, " ");
|
|
}
|
|
|
|
if (entry->flags & IMA_PCR) {
|
|
snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr);
|
|
seq_printf(m, pt(Opt_pcr), tbuf);
|
|
seq_puts(m, " ");
|
|
}
|
|
|
|
if (entry->flags & IMA_FSUUID) {
|
|
seq_printf(m, "fsuuid=%pU", entry->fsuuid);
|
|
seq_puts(m, " ");
|
|
}
|
|
|
|
if (entry->flags & IMA_UID) {
|
|
snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid));
|
|
seq_printf(m, pt(Opt_uid), tbuf);
|
|
seq_puts(m, " ");
|
|
}
|
|
|
|
if (entry->flags & IMA_EUID) {
|
|
snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->uid));
|
|
seq_printf(m, pt(Opt_euid), tbuf);
|
|
seq_puts(m, " ");
|
|
}
|
|
|
|
if (entry->flags & IMA_FOWNER) {
|
|
snprintf(tbuf, sizeof(tbuf), "%d", __kuid_val(entry->fowner));
|
|
seq_printf(m, pt(Opt_fowner), tbuf);
|
|
seq_puts(m, " ");
|
|
}
|
|
|
|
for (i = 0; i < MAX_LSM_RULES; i++) {
|
|
if (entry->lsm[i].rule) {
|
|
switch (i) {
|
|
case LSM_OBJ_USER:
|
|
seq_printf(m, pt(Opt_obj_user),
|
|
(char *)entry->lsm[i].args_p);
|
|
break;
|
|
case LSM_OBJ_ROLE:
|
|
seq_printf(m, pt(Opt_obj_role),
|
|
(char *)entry->lsm[i].args_p);
|
|
break;
|
|
case LSM_OBJ_TYPE:
|
|
seq_printf(m, pt(Opt_obj_type),
|
|
(char *)entry->lsm[i].args_p);
|
|
break;
|
|
case LSM_SUBJ_USER:
|
|
seq_printf(m, pt(Opt_subj_user),
|
|
(char *)entry->lsm[i].args_p);
|
|
break;
|
|
case LSM_SUBJ_ROLE:
|
|
seq_printf(m, pt(Opt_subj_role),
|
|
(char *)entry->lsm[i].args_p);
|
|
break;
|
|
case LSM_SUBJ_TYPE:
|
|
seq_printf(m, pt(Opt_subj_type),
|
|
(char *)entry->lsm[i].args_p);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (entry->flags & IMA_DIGSIG_REQUIRED)
|
|
seq_puts(m, "appraise_type=imasig ");
|
|
if (entry->flags & IMA_PERMIT_DIRECTIO)
|
|
seq_puts(m, "permit_directio ");
|
|
rcu_read_unlock();
|
|
seq_puts(m, "\n");
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_IMA_READ_POLICY */
|