add idl4k kernel firmware version 1.13.0.105

This commit is contained in:
Jaroslav Kysela
2015-03-26 17:22:37 +01:00
parent 5194d2792e
commit e9070cdc77
31064 changed files with 12769984 additions and 0 deletions

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# IBM Integrity Measurement Architecture
#
config IMA
bool "Integrity Measurement Architecture(IMA)"
depends on ACPI
select SECURITYFS
select CRYPTO
select CRYPTO_HMAC
select CRYPTO_MD5
select CRYPTO_SHA1
select TCG_TPM
select TCG_TIS
help
The Trusted Computing Group(TCG) runtime Integrity
Measurement Architecture(IMA) maintains a list of hash
values of executables and other sensitive system files,
as they are read or executed. If an attacker manages
to change the contents of an important system file
being measured, we can tell.
If your system has a TPM chip, then IMA also maintains
an aggregate integrity value over this list inside the
TPM hardware, so that the TPM can prove to a third party
whether or not critical system files have been modified.
Read <http://www.usenix.org/events/sec04/tech/sailer.html>
to learn more about IMA.
If unsure, say N.
config IMA_MEASURE_PCR_IDX
int
depends on IMA
range 8 14
default 10
help
IMA_MEASURE_PCR_IDX determines the TPM PCR register index
that IMA uses to maintain the integrity aggregate of the
measurement list. If unsure, use the default 10.
config IMA_AUDIT
bool
depends on IMA
default y
help
This option adds a kernel parameter 'ima_audit', which
allows informational auditing messages to be enabled
at boot. If this option is selected, informational integrity
auditing messages can be enabled with 'ima_audit=1' on
the kernel command line.
config IMA_LSM_RULES
bool
depends on IMA && AUDIT && (SECURITY_SELINUX || SECURITY_SMACK)
default y
help
Disabling this option will disregard LSM based policy rules.

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#
# Makefile for building Trusted Computing Group's(TCG) runtime Integrity
# Measurement Architecture(IMA).
#
obj-$(CONFIG_IMA) += ima.o
ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
ima_policy.o ima_iint.o ima_audit.o

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/*
* Copyright (C) 2005,2006,2007,2008 IBM Corporation
*
* Authors:
* Reiner Sailer <sailer@watson.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.h
* internal Integrity Measurement Architecture (IMA) definitions
*/
#ifndef __LINUX_IMA_H
#define __LINUX_IMA_H
#include <linux/types.h>
#include <linux/crypto.h>
#include <linux/security.h>
#include <linux/hash.h>
#include <linux/tpm.h>
#include <linux/audit.h>
enum ima_show_type { IMA_SHOW_BINARY, IMA_SHOW_ASCII };
enum tpm_pcrs { TPM_PCR0 = 0, TPM_PCR8 = 8 };
/* digest size for IMA, fits SHA1 or MD5 */
#define IMA_DIGEST_SIZE 20
#define IMA_EVENT_NAME_LEN_MAX 255
#define IMA_HASH_BITS 9
#define IMA_MEASURE_HTABLE_SIZE (1 << IMA_HASH_BITS)
/* set during initialization */
extern int ima_initialized;
extern int ima_used_chip;
extern char *ima_hash;
/* IMA inode template definition */
struct ima_template_data {
u8 digest[IMA_DIGEST_SIZE]; /* sha1/md5 measurement hash */
char file_name[IMA_EVENT_NAME_LEN_MAX + 1]; /* name + \0 */
};
struct ima_template_entry {
u8 digest[IMA_DIGEST_SIZE]; /* sha1 or md5 measurement hash */
const char *template_name;
int template_len;
struct ima_template_data template;
};
struct ima_queue_entry {
struct hlist_node hnext; /* place in hash collision list */
struct list_head later; /* place in ima_measurements list */
struct ima_template_entry *entry;
};
extern struct list_head ima_measurements; /* list of all measurements */
/* declarations */
void integrity_audit_msg(int audit_msgno, struct inode *inode,
const unsigned char *fname, const char *op,
const char *cause, int result, int info);
/* Internal IMA function definitions */
void ima_iintcache_init(void);
int ima_init(void);
void ima_cleanup(void);
int ima_fs_init(void);
void ima_fs_cleanup(void);
int ima_add_template_entry(struct ima_template_entry *entry, int violation,
const char *op, struct inode *inode);
int ima_calc_hash(struct file *file, char *digest);
int ima_calc_template_hash(int template_len, void *template, char *digest);
int ima_calc_boot_aggregate(char *digest);
void ima_add_violation(struct inode *inode, const unsigned char *filename,
const char *op, const char *cause);
/*
* used to protect h_table and sha_table
*/
extern spinlock_t ima_queue_lock;
struct ima_h_table {
atomic_long_t len; /* number of stored measurements in the list */
atomic_long_t violations;
struct hlist_head queue[IMA_MEASURE_HTABLE_SIZE];
};
extern struct ima_h_table ima_htable;
static inline unsigned long ima_hash_key(u8 *digest)
{
return hash_long(*digest, IMA_HASH_BITS);
}
/* iint cache flags */
#define IMA_MEASURED 1
#define IMA_IINT_DUMP_STACK 512
/* integrity data associated with an inode */
struct ima_iint_cache {
u64 version; /* track inode changes */
unsigned long flags;
u8 digest[IMA_DIGEST_SIZE];
struct mutex mutex; /* protects: version, flags, digest */
long readcount; /* measured files readcount */
long writecount; /* measured files writecount */
long opencount; /* opens reference count */
struct kref refcount; /* ima_iint_cache reference count */
struct rcu_head rcu;
};
/* LIM API function definitions */
int ima_must_measure(struct ima_iint_cache *iint, struct inode *inode,
int mask, int function);
int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file);
void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
const unsigned char *filename);
int ima_store_template(struct ima_template_entry *entry, int violation,
struct inode *inode);
void ima_template_show(struct seq_file *m, void *e,
enum ima_show_type show);
/* radix tree calls to lookup, insert, delete
* integrity data associated with an inode.
*/
struct ima_iint_cache *ima_iint_insert(struct inode *inode);
struct ima_iint_cache *ima_iint_find_get(struct inode *inode);
struct ima_iint_cache *ima_iint_find_insert_get(struct inode *inode);
void ima_iint_delete(struct inode *inode);
void iint_free(struct kref *kref);
void iint_rcu_free(struct rcu_head *rcu);
/* IMA policy related functions */
enum ima_hooks { PATH_CHECK = 1, FILE_MMAP, BPRM_CHECK };
int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask);
void ima_init_policy(void);
void ima_update_policy(void);
int ima_parse_add_rule(char *);
void ima_delete_rules(void);
/* LSM based policy rules require audit */
#ifdef CONFIG_IMA_LSM_RULES
#define security_filter_rule_init security_audit_rule_init
#define security_filter_rule_match security_audit_rule_match
#else
static inline int security_filter_rule_init(u32 field, u32 op, char *rulestr,
void **lsmrule)
{
return -EINVAL;
}
static inline int security_filter_rule_match(u32 secid, u32 field, u32 op,
void *lsmrule,
struct audit_context *actx)
{
return -EINVAL;
}
#endif /* CONFIG_IMA_LSM_RULES */
#endif

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/*
* Copyright (C) 2008 IBM Corporation
*
* Author: 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_api.c
* Implements must_measure, collect_measurement, store_measurement,
* and store_template.
*/
#include <linux/module.h>
#include "ima.h"
static const char *IMA_TEMPLATE_NAME = "ima";
/*
* ima_store_template - store ima template measurements
*
* Calculate the hash of a template entry, add the template entry
* to an ordered list of measurement entries maintained inside the kernel,
* and also update the aggregate integrity value (maintained inside the
* configured TPM PCR) over the hashes of the current list of measurement
* entries.
*
* Applications retrieve the current kernel-held measurement list through
* the securityfs entries in /sys/kernel/security/ima. The signed aggregate
* TPM PCR (called quote) can be retrieved using a TPM user space library
* and is used to validate the measurement list.
*
* Returns 0 on success, error code otherwise
*/
int ima_store_template(struct ima_template_entry *entry,
int violation, struct inode *inode)
{
const char *op = "add_template_measure";
const char *audit_cause = "hashing_error";
int result;
memset(entry->digest, 0, sizeof(entry->digest));
entry->template_name = IMA_TEMPLATE_NAME;
entry->template_len = sizeof(entry->template);
if (!violation) {
result = ima_calc_template_hash(entry->template_len,
&entry->template,
entry->digest);
if (result < 0) {
integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode,
entry->template_name, op,
audit_cause, result, 0);
return result;
}
}
result = ima_add_template_entry(entry, violation, op, inode);
return result;
}
/*
* ima_add_violation - add violation to measurement list.
*
* Violations are flagged in the measurement list with zero hash values.
* By extending the PCR with 0xFF's instead of with zeroes, the PCR
* value is invalidated.
*/
void ima_add_violation(struct inode *inode, const unsigned char *filename,
const char *op, const char *cause)
{
struct ima_template_entry *entry;
int violation = 1;
int result;
/* can overflow, only indicator */
atomic_long_inc(&ima_htable.violations);
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry) {
result = -ENOMEM;
goto err_out;
}
memset(&entry->template, 0, sizeof(entry->template));
strncpy(entry->template.file_name, filename, IMA_EVENT_NAME_LEN_MAX);
result = ima_store_template(entry, violation, inode);
if (result < 0)
kfree(entry);
err_out:
integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
op, cause, result, 0);
}
/**
* ima_must_measure - measure decision based on policy.
* @inode: pointer to inode to measure
* @mask: contains the permission mask (MAY_READ, MAY_WRITE, MAY_EXECUTE)
* @function: calling function (PATH_CHECK, BPRM_CHECK, FILE_MMAP)
*
* The policy is defined in terms of keypairs:
* subj=, obj=, type=, func=, mask=, fsmagic=
* subj,obj, and type: are LSM specific.
* func: PATH_CHECK | BPRM_CHECK | FILE_MMAP
* mask: contains the permission mask
* fsmagic: hex value
*
* Must be called with iint->mutex held.
*
* Return 0 to measure. Return 1 if already measured.
* For matching a DONT_MEASURE policy, no policy, or other
* error, return an error code.
*/
int ima_must_measure(struct ima_iint_cache *iint, struct inode *inode,
int mask, int function)
{
int must_measure;
if (iint->flags & IMA_MEASURED)
return 1;
must_measure = ima_match_policy(inode, function, mask);
return must_measure ? 0 : -EACCES;
}
/*
* ima_collect_measurement - collect file measurement
*
* Calculate the file hash, if it doesn't already exist,
* storing the measurement and i_version in the iint.
*
* Must be called with iint->mutex held.
*
* Return 0 on success, error code otherwise
*/
int ima_collect_measurement(struct ima_iint_cache *iint, struct file *file)
{
int result = -EEXIST;
if (!(iint->flags & IMA_MEASURED)) {
u64 i_version = file->f_dentry->d_inode->i_version;
memset(iint->digest, 0, IMA_DIGEST_SIZE);
result = ima_calc_hash(file, iint->digest);
if (!result)
iint->version = i_version;
}
return result;
}
/*
* ima_store_measurement - store file measurement
*
* Create an "ima" template and then store the template by calling
* ima_store_template.
*
* We only get here if the inode has not already been measured,
* but the measurement could already exist:
* - multiple copies of the same file on either the same or
* different filesystems.
* - the inode was previously flushed as well as the iint info,
* containing the hashing info.
*
* Must be called with iint->mutex held.
*/
void ima_store_measurement(struct ima_iint_cache *iint, struct file *file,
const unsigned char *filename)
{
const char *op = "add_template_measure";
const char *audit_cause = "ENOMEM";
int result = -ENOMEM;
struct inode *inode = file->f_dentry->d_inode;
struct ima_template_entry *entry;
int violation = 0;
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry) {
integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
op, audit_cause, result, 0);
return;
}
memset(&entry->template, 0, sizeof(entry->template));
memcpy(entry->template.digest, iint->digest, IMA_DIGEST_SIZE);
strncpy(entry->template.file_name, filename, IMA_EVENT_NAME_LEN_MAX);
result = ima_store_template(entry, violation, inode);
if (!result)
iint->flags |= IMA_MEASURED;
else
kfree(entry);
}

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/*
* Copyright (C) 2008 IBM Corporation
* Author: 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: integrity_audit.c
* Audit calls for the integrity subsystem
*/
#include <linux/fs.h>
#include <linux/audit.h>
#include "ima.h"
static int ima_audit;
#ifdef CONFIG_IMA_AUDIT
/* ima_audit_setup - enable informational auditing messages */
static int __init ima_audit_setup(char *str)
{
unsigned long audit;
if (!strict_strtoul(str, 0, &audit))
ima_audit = audit ? 1 : 0;
return 1;
}
__setup("ima_audit=", ima_audit_setup);
#endif
void integrity_audit_msg(int audit_msgno, struct inode *inode,
const unsigned char *fname, const char *op,
const char *cause, int result, int audit_info)
{
struct audit_buffer *ab;
if (!ima_audit && audit_info == 1) /* Skip informational messages */
return;
ab = audit_log_start(current->audit_context, GFP_KERNEL, audit_msgno);
audit_log_format(ab, "integrity: pid=%d uid=%u auid=%u ses=%u",
current->pid, current_cred()->uid,
audit_get_loginuid(current),
audit_get_sessionid(current));
audit_log_task_context(ab);
audit_log_format(ab, " op=");
audit_log_string(ab, op);
audit_log_format(ab, " cause=");
audit_log_string(ab, cause);
audit_log_format(ab, " comm=");
audit_log_untrustedstring(ab, current->comm);
if (fname) {
audit_log_format(ab, " name=");
audit_log_untrustedstring(ab, fname);
}
if (inode)
audit_log_format(ab, " dev=%s ino=%lu",
inode->i_sb->s_id, inode->i_ino);
audit_log_format(ab, " res=%d", !result ? 0 : 1);
audit_log_end(ab);
}

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/*
* Copyright (C) 2005,2006,2007,2008 IBM Corporation
*
* Authors:
* Mimi Zohar <zohar@us.ibm.com>
* Kylene Hall <kjhall@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_crypto.c
* Calculates md5/sha1 file hash, template hash, boot-aggreate hash
*/
#include <linux/kernel.h>
#include <linux/file.h>
#include <linux/crypto.h>
#include <linux/scatterlist.h>
#include <linux/err.h>
#include "ima.h"
static int init_desc(struct hash_desc *desc)
{
int rc;
desc->tfm = crypto_alloc_hash(ima_hash, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(desc->tfm)) {
pr_info("failed to load %s transform: %ld\n",
ima_hash, PTR_ERR(desc->tfm));
rc = PTR_ERR(desc->tfm);
return rc;
}
desc->flags = 0;
rc = crypto_hash_init(desc);
if (rc)
crypto_free_hash(desc->tfm);
return rc;
}
/*
* Calculate the MD5/SHA1 file digest
*/
int ima_calc_hash(struct file *file, char *digest)
{
struct hash_desc desc;
struct scatterlist sg[1];
loff_t i_size, offset = 0;
char *rbuf;
int rc;
rc = init_desc(&desc);
if (rc != 0)
return rc;
rbuf = kzalloc(PAGE_SIZE, GFP_KERNEL);
if (!rbuf) {
rc = -ENOMEM;
goto out;
}
i_size = i_size_read(file->f_dentry->d_inode);
while (offset < i_size) {
int rbuf_len;
rbuf_len = kernel_read(file, offset, rbuf, PAGE_SIZE);
if (rbuf_len < 0) {
rc = rbuf_len;
break;
}
if (rbuf_len == 0)
break;
offset += rbuf_len;
sg_init_one(sg, rbuf, rbuf_len);
rc = crypto_hash_update(&desc, sg, rbuf_len);
if (rc)
break;
}
kfree(rbuf);
if (!rc)
rc = crypto_hash_final(&desc, digest);
out:
crypto_free_hash(desc.tfm);
return rc;
}
/*
* Calculate the hash of a given template
*/
int ima_calc_template_hash(int template_len, void *template, char *digest)
{
struct hash_desc desc;
struct scatterlist sg[1];
int rc;
rc = init_desc(&desc);
if (rc != 0)
return rc;
sg_init_one(sg, template, template_len);
rc = crypto_hash_update(&desc, sg, template_len);
if (!rc)
rc = crypto_hash_final(&desc, digest);
crypto_free_hash(desc.tfm);
return rc;
}
static void __init ima_pcrread(int idx, u8 *pcr)
{
if (!ima_used_chip)
return;
if (tpm_pcr_read(TPM_ANY_NUM, idx, pcr) != 0)
pr_err("Error Communicating to TPM chip\n");
}
/*
* Calculate the boot aggregate hash
*/
int __init ima_calc_boot_aggregate(char *digest)
{
struct hash_desc desc;
struct scatterlist sg;
u8 pcr_i[IMA_DIGEST_SIZE];
int rc, i;
rc = init_desc(&desc);
if (rc != 0)
return rc;
/* cumulative sha1 over tpm registers 0-7 */
for (i = TPM_PCR0; i < TPM_PCR8; i++) {
ima_pcrread(i, pcr_i);
/* now accumulate with current aggregate */
sg_init_one(&sg, pcr_i, IMA_DIGEST_SIZE);
rc = crypto_hash_update(&desc, &sg, IMA_DIGEST_SIZE);
}
if (!rc)
crypto_hash_final(&desc, digest);
crypto_free_hash(desc.tfm);
return rc;
}

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/*
* Copyright (C) 2005,2006,2007,2008 IBM Corporation
*
* Authors:
* Kylene Hall <kjhall@us.ibm.com>
* Reiner Sailer <sailer@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_fs.c
* implemenents security file system for reporting
* current measurement list and IMA statistics
*/
#include <linux/fcntl.h>
#include <linux/module.h>
#include <linux/seq_file.h>
#include <linux/rculist.h>
#include <linux/rcupdate.h>
#include <linux/parser.h>
#include "ima.h"
static int valid_policy = 1;
#define TMPBUFLEN 12
static ssize_t ima_show_htable_value(char __user *buf, size_t count,
loff_t *ppos, atomic_long_t *val)
{
char tmpbuf[TMPBUFLEN];
ssize_t len;
len = scnprintf(tmpbuf, TMPBUFLEN, "%li\n", atomic_long_read(val));
return simple_read_from_buffer(buf, count, ppos, tmpbuf, len);
}
static ssize_t ima_show_htable_violations(struct file *filp,
char __user *buf,
size_t count, loff_t *ppos)
{
return ima_show_htable_value(buf, count, ppos, &ima_htable.violations);
}
static const struct file_operations ima_htable_violations_ops = {
.read = ima_show_htable_violations
};
static ssize_t ima_show_measurements_count(struct file *filp,
char __user *buf,
size_t count, loff_t *ppos)
{
return ima_show_htable_value(buf, count, ppos, &ima_htable.len);
}
static const struct file_operations ima_measurements_count_ops = {
.read = ima_show_measurements_count
};
/* returns pointer to hlist_node */
static void *ima_measurements_start(struct seq_file *m, loff_t *pos)
{
loff_t l = *pos;
struct ima_queue_entry *qe;
/* we need a lock since pos could point beyond last element */
rcu_read_lock();
list_for_each_entry_rcu(qe, &ima_measurements, later) {
if (!l--) {
rcu_read_unlock();
return qe;
}
}
rcu_read_unlock();
return NULL;
}
static void *ima_measurements_next(struct seq_file *m, void *v, loff_t *pos)
{
struct ima_queue_entry *qe = v;
/* lock protects when reading beyond last element
* against concurrent list-extension
*/
rcu_read_lock();
qe = list_entry_rcu(qe->later.next,
struct ima_queue_entry, later);
rcu_read_unlock();
(*pos)++;
return (&qe->later == &ima_measurements) ? NULL : qe;
}
static void ima_measurements_stop(struct seq_file *m, void *v)
{
}
static void ima_putc(struct seq_file *m, void *data, int datalen)
{
while (datalen--)
seq_putc(m, *(char *)data++);
}
/* print format:
* 32bit-le=pcr#
* char[20]=template digest
* 32bit-le=template name size
* char[n]=template name
* eventdata[n]=template specific data
*/
static int ima_measurements_show(struct seq_file *m, void *v)
{
/* the list never shrinks, so we don't need a lock here */
struct ima_queue_entry *qe = v;
struct ima_template_entry *e;
int namelen;
u32 pcr = CONFIG_IMA_MEASURE_PCR_IDX;
/* get entry */
e = qe->entry;
if (e == NULL)
return -1;
/*
* 1st: PCRIndex
* PCR used is always the same (config option) in
* little-endian format
*/
ima_putc(m, &pcr, sizeof pcr);
/* 2nd: template digest */
ima_putc(m, e->digest, IMA_DIGEST_SIZE);
/* 3rd: template name size */
namelen = strlen(e->template_name);
ima_putc(m, &namelen, sizeof namelen);
/* 4th: template name */
ima_putc(m, (void *)e->template_name, namelen);
/* 5th: template specific data */
ima_template_show(m, (struct ima_template_data *)&e->template,
IMA_SHOW_BINARY);
return 0;
}
static const struct seq_operations ima_measurments_seqops = {
.start = ima_measurements_start,
.next = ima_measurements_next,
.stop = ima_measurements_stop,
.show = ima_measurements_show
};
static int ima_measurements_open(struct inode *inode, struct file *file)
{
return seq_open(file, &ima_measurments_seqops);
}
static const struct file_operations ima_measurements_ops = {
.open = ima_measurements_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static void ima_print_digest(struct seq_file *m, u8 *digest)
{
int i;
for (i = 0; i < IMA_DIGEST_SIZE; i++)
seq_printf(m, "%02x", *(digest + i));
}
void ima_template_show(struct seq_file *m, void *e, enum ima_show_type show)
{
struct ima_template_data *entry = e;
int namelen;
switch (show) {
case IMA_SHOW_ASCII:
ima_print_digest(m, entry->digest);
seq_printf(m, " %s\n", entry->file_name);
break;
case IMA_SHOW_BINARY:
ima_putc(m, entry->digest, IMA_DIGEST_SIZE);
namelen = strlen(entry->file_name);
ima_putc(m, &namelen, sizeof namelen);
ima_putc(m, entry->file_name, namelen);
default:
break;
}
}
/* print in ascii */
static int ima_ascii_measurements_show(struct seq_file *m, void *v)
{
/* the list never shrinks, so we don't need a lock here */
struct ima_queue_entry *qe = v;
struct ima_template_entry *e;
/* get entry */
e = qe->entry;
if (e == NULL)
return -1;
/* 1st: PCR used (config option) */
seq_printf(m, "%2d ", CONFIG_IMA_MEASURE_PCR_IDX);
/* 2nd: SHA1 template hash */
ima_print_digest(m, e->digest);
/* 3th: template name */
seq_printf(m, " %s ", e->template_name);
/* 4th: template specific data */
ima_template_show(m, (struct ima_template_data *)&e->template,
IMA_SHOW_ASCII);
return 0;
}
static const struct seq_operations ima_ascii_measurements_seqops = {
.start = ima_measurements_start,
.next = ima_measurements_next,
.stop = ima_measurements_stop,
.show = ima_ascii_measurements_show
};
static int ima_ascii_measurements_open(struct inode *inode, struct file *file)
{
return seq_open(file, &ima_ascii_measurements_seqops);
}
static const struct file_operations ima_ascii_measurements_ops = {
.open = ima_ascii_measurements_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static ssize_t ima_write_policy(struct file *file, const char __user *buf,
size_t datalen, loff_t *ppos)
{
char *data;
int rc;
if (datalen >= PAGE_SIZE)
return -ENOMEM;
if (*ppos != 0) {
/* No partial writes. */
return -EINVAL;
}
data = kmalloc(datalen + 1, GFP_KERNEL);
if (!data)
return -ENOMEM;
if (copy_from_user(data, buf, datalen)) {
kfree(data);
return -EFAULT;
}
*(data + datalen) = '\0';
rc = ima_parse_add_rule(data);
if (rc < 0) {
datalen = -EINVAL;
valid_policy = 0;
}
kfree(data);
return datalen;
}
static struct dentry *ima_dir;
static struct dentry *binary_runtime_measurements;
static struct dentry *ascii_runtime_measurements;
static struct dentry *runtime_measurements_count;
static struct dentry *violations;
static struct dentry *ima_policy;
static atomic_t policy_opencount = ATOMIC_INIT(1);
/*
* ima_open_policy: sequentialize access to the policy file
*/
int ima_open_policy(struct inode * inode, struct file * filp)
{
/* No point in being allowed to open it if you aren't going to write */
if (!(filp->f_flags & O_WRONLY))
return -EACCES;
if (atomic_dec_and_test(&policy_opencount))
return 0;
return -EBUSY;
}
/*
* ima_release_policy - start using the new measure policy rules.
*
* Initially, ima_measure points to the default policy rules, now
* 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)
{
if (!valid_policy) {
ima_delete_rules();
valid_policy = 1;
atomic_set(&policy_opencount, 1);
return 0;
}
ima_update_policy();
securityfs_remove(ima_policy);
ima_policy = NULL;
return 0;
}
static const struct file_operations ima_measure_policy_ops = {
.open = ima_open_policy,
.write = ima_write_policy,
.release = ima_release_policy
};
int __init ima_fs_init(void)
{
ima_dir = securityfs_create_dir("ima", NULL);
if (IS_ERR(ima_dir))
return -1;
binary_runtime_measurements =
securityfs_create_file("binary_runtime_measurements",
S_IRUSR | S_IRGRP, ima_dir, NULL,
&ima_measurements_ops);
if (IS_ERR(binary_runtime_measurements))
goto out;
ascii_runtime_measurements =
securityfs_create_file("ascii_runtime_measurements",
S_IRUSR | S_IRGRP, ima_dir, NULL,
&ima_ascii_measurements_ops);
if (IS_ERR(ascii_runtime_measurements))
goto out;
runtime_measurements_count =
securityfs_create_file("runtime_measurements_count",
S_IRUSR | S_IRGRP, ima_dir, NULL,
&ima_measurements_count_ops);
if (IS_ERR(runtime_measurements_count))
goto out;
violations =
securityfs_create_file("violations", S_IRUSR | S_IRGRP,
ima_dir, NULL, &ima_htable_violations_ops);
if (IS_ERR(violations))
goto out;
ima_policy = securityfs_create_file("policy",
S_IWUSR,
ima_dir, NULL,
&ima_measure_policy_ops);
if (IS_ERR(ima_policy))
goto out;
return 0;
out:
securityfs_remove(runtime_measurements_count);
securityfs_remove(ascii_runtime_measurements);
securityfs_remove(binary_runtime_measurements);
securityfs_remove(ima_dir);
securityfs_remove(ima_policy);
return -1;
}
void __exit ima_fs_cleanup(void)
{
securityfs_remove(violations);
securityfs_remove(runtime_measurements_count);
securityfs_remove(ascii_runtime_measurements);
securityfs_remove(binary_runtime_measurements);
securityfs_remove(ima_dir);
securityfs_remove(ima_policy);
}

View File

@@ -0,0 +1,204 @@
/*
* Copyright (C) 2008 IBM Corporation
*
* Authors:
* 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_iint.c
* - implements the IMA hooks: ima_inode_alloc, ima_inode_free
* - cache integrity information associated with an inode
* using a radix tree.
*/
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/radix-tree.h>
#include "ima.h"
#define ima_iint_delete ima_inode_free
RADIX_TREE(ima_iint_store, GFP_ATOMIC);
DEFINE_SPINLOCK(ima_iint_lock);
static struct kmem_cache *iint_cache __read_mostly;
/* ima_iint_find_get - return the iint associated with an inode
*
* ima_iint_find_get gets a reference to the iint. Caller must
* remember to put the iint reference.
*/
struct ima_iint_cache *ima_iint_find_get(struct inode *inode)
{
struct ima_iint_cache *iint;
rcu_read_lock();
iint = radix_tree_lookup(&ima_iint_store, (unsigned long)inode);
if (!iint)
goto out;
kref_get(&iint->refcount);
out:
rcu_read_unlock();
return iint;
}
/* Allocate memory for the iint associated with the inode
* from the iint_cache slab, initialize the iint, and
* insert it into the radix tree.
*
* On success return a pointer to the iint; on failure return NULL.
*/
struct ima_iint_cache *ima_iint_insert(struct inode *inode)
{
struct ima_iint_cache *iint = NULL;
int rc = 0;
if (!ima_initialized)
return iint;
iint = kmem_cache_alloc(iint_cache, GFP_NOFS);
if (!iint)
return iint;
rc = radix_tree_preload(GFP_NOFS);
if (rc < 0)
goto out;
spin_lock(&ima_iint_lock);
rc = radix_tree_insert(&ima_iint_store, (unsigned long)inode, iint);
spin_unlock(&ima_iint_lock);
out:
if (rc < 0) {
kmem_cache_free(iint_cache, iint);
if (rc == -EEXIST) {
spin_lock(&ima_iint_lock);
iint = radix_tree_lookup(&ima_iint_store,
(unsigned long)inode);
spin_unlock(&ima_iint_lock);
} else
iint = NULL;
}
radix_tree_preload_end();
return iint;
}
/**
* ima_inode_alloc - allocate an iint associated with an inode
* @inode: pointer to the inode
*
* Return 0 on success, 1 on failure.
*/
int ima_inode_alloc(struct inode *inode)
{
struct ima_iint_cache *iint;
if (!ima_initialized)
return 0;
iint = ima_iint_insert(inode);
if (!iint)
return 1;
return 0;
}
/* ima_iint_find_insert_get - get the iint associated with an inode
*
* Most insertions are done at inode_alloc, except those allocated
* before late_initcall. When the iint does not exist, allocate it,
* initialize and insert it, and increment the iint refcount.
*
* (Can't initialize at security_initcall before any inodes are
* allocated, got to wait at least until proc_init.)
*
* Return the iint.
*/
struct ima_iint_cache *ima_iint_find_insert_get(struct inode *inode)
{
struct ima_iint_cache *iint = NULL;
iint = ima_iint_find_get(inode);
if (iint)
return iint;
iint = ima_iint_insert(inode);
if (iint)
kref_get(&iint->refcount);
return iint;
}
EXPORT_SYMBOL_GPL(ima_iint_find_insert_get);
/* iint_free - called when the iint refcount goes to zero */
void iint_free(struct kref *kref)
{
struct ima_iint_cache *iint = container_of(kref, struct ima_iint_cache,
refcount);
iint->version = 0;
iint->flags = 0UL;
if (iint->readcount != 0) {
printk(KERN_INFO "%s: readcount: %ld\n", __FUNCTION__,
iint->readcount);
iint->readcount = 0;
}
if (iint->writecount != 0) {
printk(KERN_INFO "%s: writecount: %ld\n", __FUNCTION__,
iint->writecount);
iint->writecount = 0;
}
if (iint->opencount != 0) {
printk(KERN_INFO "%s: opencount: %ld\n", __FUNCTION__,
iint->opencount);
iint->opencount = 0;
}
kref_set(&iint->refcount, 1);
kmem_cache_free(iint_cache, iint);
}
void iint_rcu_free(struct rcu_head *rcu_head)
{
struct ima_iint_cache *iint = container_of(rcu_head,
struct ima_iint_cache, rcu);
kref_put(&iint->refcount, iint_free);
}
/**
* ima_iint_delete - called on integrity_inode_free
* @inode: pointer to the inode
*
* Free the integrity information(iint) associated with an inode.
*/
void ima_iint_delete(struct inode *inode)
{
struct ima_iint_cache *iint;
if (!ima_initialized)
return;
spin_lock(&ima_iint_lock);
iint = radix_tree_delete(&ima_iint_store, (unsigned long)inode);
spin_unlock(&ima_iint_lock);
if (iint)
call_rcu(&iint->rcu, iint_rcu_free);
}
static void init_once(void *foo)
{
struct ima_iint_cache *iint = foo;
memset(iint, 0, sizeof *iint);
iint->version = 0;
iint->flags = 0UL;
mutex_init(&iint->mutex);
iint->readcount = 0;
iint->writecount = 0;
iint->opencount = 0;
kref_set(&iint->refcount, 1);
}
void __init ima_iintcache_init(void)
{
iint_cache =
kmem_cache_create("iint_cache", sizeof(struct ima_iint_cache), 0,
SLAB_PANIC, init_once);
}

View File

@@ -0,0 +1,96 @@
/*
* Copyright (C) 2005,2006,2007,2008 IBM Corporation
*
* Authors:
* Reiner Sailer <sailer@watson.ibm.com>
* Leendert van Doorn <leendert@watson.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_init.c
* initialization and cleanup functions
*/
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/err.h>
#include "ima.h"
/* name for boot aggregate entry */
static const char *boot_aggregate_name = "boot_aggregate";
int ima_used_chip;
/* Add the boot aggregate to the IMA measurement list and extend
* the PCR register.
*
* Calculate the boot aggregate, a SHA1 over tpm registers 0-7,
* assuming a TPM chip exists, and zeroes if the TPM chip does not
* exist. Add the boot aggregate measurement to the measurement
* list and extend the PCR register.
*
* If a tpm chip does not exist, indicate the core root of trust is
* not hardware based by invalidating the aggregate PCR value.
* (The aggregate PCR value is invalidated by adding one value to
* the measurement list and extending the aggregate PCR value with
* a different value.) Violations add a zero entry to the measurement
* list and extend the aggregate PCR value with ff...ff's.
*/
static void __init ima_add_boot_aggregate(void)
{
struct ima_template_entry *entry;
const char *op = "add_boot_aggregate";
const char *audit_cause = "ENOMEM";
int result = -ENOMEM;
int violation = 1;
entry = kmalloc(sizeof(*entry), GFP_KERNEL);
if (!entry)
goto err_out;
memset(&entry->template, 0, sizeof(entry->template));
strncpy(entry->template.file_name, boot_aggregate_name,
IMA_EVENT_NAME_LEN_MAX);
if (ima_used_chip) {
violation = 0;
result = ima_calc_boot_aggregate(entry->template.digest);
if (result < 0) {
audit_cause = "hashing_error";
kfree(entry);
goto err_out;
}
}
result = ima_store_template(entry, violation, NULL);
if (result < 0)
kfree(entry);
return;
err_out:
integrity_audit_msg(AUDIT_INTEGRITY_PCR, NULL, boot_aggregate_name, op,
audit_cause, result, 0);
}
int __init ima_init(void)
{
u8 pcr_i[IMA_DIGEST_SIZE];
int rc;
ima_used_chip = 0;
rc = tpm_pcr_read(TPM_ANY_NUM, 0, pcr_i);
if (rc == 0)
ima_used_chip = 1;
if (!ima_used_chip)
pr_info("No TPM chip found, activating TPM-bypass!\n");
ima_add_boot_aggregate(); /* boot aggregate must be first entry */
ima_init_policy();
return ima_fs_init();
}
void __exit ima_cleanup(void)
{
ima_fs_cleanup();
}

View File

@@ -0,0 +1,368 @@
/*
* 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_path_check.
*/
#include <linux/module.h>
#include <linux/file.h>
#include <linux/binfmts.h>
#include <linux/mount.h>
#include <linux/mman.h>
#include "ima.h"
int ima_initialized;
char *ima_hash = "sha1";
static int __init hash_setup(char *str)
{
if (strncmp(str, "md5", 3) == 0)
ima_hash = "md5";
return 1;
}
__setup("ima_hash=", hash_setup);
/**
* ima_file_free - called on __fput()
* @file: pointer to file structure being freed
*
* Flag files that changed, based on i_version;
* and decrement the iint readcount/writecount.
*/
void ima_file_free(struct file *file)
{
struct inode *inode = file->f_dentry->d_inode;
struct ima_iint_cache *iint;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return;
iint = ima_iint_find_get(inode);
if (!iint)
return;
mutex_lock(&iint->mutex);
if (iint->opencount <= 0) {
printk(KERN_INFO
"%s: %s open/free imbalance (r:%ld w:%ld o:%ld f:%ld)\n",
__FUNCTION__, file->f_dentry->d_name.name,
iint->readcount, iint->writecount,
iint->opencount, atomic_long_read(&file->f_count));
if (!(iint->flags & IMA_IINT_DUMP_STACK)) {
dump_stack();
iint->flags |= IMA_IINT_DUMP_STACK;
}
}
iint->opencount--;
if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
iint->readcount--;
if (file->f_mode & FMODE_WRITE) {
iint->writecount--;
if (iint->writecount == 0) {
if (iint->version != inode->i_version)
iint->flags &= ~IMA_MEASURED;
}
}
mutex_unlock(&iint->mutex);
kref_put(&iint->refcount, iint_free);
}
/* ima_read_write_check - reflect possible reading/writing errors in the PCR.
*
* When opening a file for read, if the file is already open for write,
* the file could change, resulting in a file measurement error.
*
* Opening a file for write, if the file is already open for read, results
* in a time of measure, time of use (ToMToU) error.
*
* In either case invalidate the PCR.
*/
enum iint_pcr_error { TOMTOU, OPEN_WRITERS };
static void ima_read_write_check(enum iint_pcr_error error,
struct ima_iint_cache *iint,
struct inode *inode,
const unsigned char *filename)
{
switch (error) {
case TOMTOU:
if (iint->readcount > 0)
ima_add_violation(inode, filename, "invalid_pcr",
"ToMToU");
break;
case OPEN_WRITERS:
if (iint->writecount > 0)
ima_add_violation(inode, filename, "invalid_pcr",
"open_writers");
break;
}
}
static int get_path_measurement(struct ima_iint_cache *iint, struct file *file,
const unsigned char *filename)
{
int rc = 0;
iint->opencount++;
iint->readcount++;
rc = ima_collect_measurement(iint, file);
if (!rc)
ima_store_measurement(iint, file, filename);
return rc;
}
static void ima_update_counts(struct ima_iint_cache *iint, int mask)
{
iint->opencount++;
if ((mask & MAY_WRITE) || (mask == 0))
iint->writecount++;
else if (mask & (MAY_READ | MAY_EXEC))
iint->readcount++;
}
/**
* ima_path_check - based on policy, collect/store measurement.
* @path: contains a pointer to the path to be measured
* @mask: contains MAY_READ, MAY_WRITE or MAY_EXECUTE
*
* Measure the file being open for readonly, based on the
* ima_must_measure() policy decision.
*
* Keep read/write counters for all files, but 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.
*
* Always return 0 and audit dentry_open failures.
* (Return code will be based upon measurement appraisal.)
*/
int ima_path_check(struct path *path, int mask, int update_counts)
{
struct inode *inode = path->dentry->d_inode;
struct ima_iint_cache *iint;
struct file *file = NULL;
int rc;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return 0;
iint = ima_iint_find_insert_get(inode);
if (!iint)
return 0;
mutex_lock(&iint->mutex);
if (update_counts)
ima_update_counts(iint, mask);
rc = ima_must_measure(iint, inode, MAY_READ, PATH_CHECK);
if (rc < 0)
goto out;
if ((mask & MAY_WRITE) || (mask == 0))
ima_read_write_check(TOMTOU, iint, inode,
path->dentry->d_name.name);
if ((mask & (MAY_WRITE | MAY_READ | MAY_EXEC)) != MAY_READ)
goto out;
ima_read_write_check(OPEN_WRITERS, iint, inode,
path->dentry->d_name.name);
if (!(iint->flags & IMA_MEASURED)) {
struct dentry *dentry = dget(path->dentry);
struct vfsmount *mnt = mntget(path->mnt);
file = dentry_open(dentry, mnt, O_RDONLY | O_LARGEFILE,
current_cred());
if (IS_ERR(file)) {
int audit_info = 0;
integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode,
dentry->d_name.name,
"add_measurement",
"dentry_open failed",
1, audit_info);
file = NULL;
goto out;
}
rc = get_path_measurement(iint, file, dentry->d_name.name);
}
out:
mutex_unlock(&iint->mutex);
if (file)
fput(file);
kref_put(&iint->refcount, iint_free);
return 0;
}
EXPORT_SYMBOL_GPL(ima_path_check);
static int process_measurement(struct file *file, const unsigned char *filename,
int mask, int function)
{
struct inode *inode = file->f_dentry->d_inode;
struct ima_iint_cache *iint;
int rc;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return 0;
iint = ima_iint_find_insert_get(inode);
if (!iint)
return -ENOMEM;
mutex_lock(&iint->mutex);
rc = ima_must_measure(iint, inode, mask, function);
if (rc != 0)
goto out;
rc = ima_collect_measurement(iint, file);
if (!rc)
ima_store_measurement(iint, file, filename);
out:
mutex_unlock(&iint->mutex);
kref_put(&iint->refcount, iint_free);
return rc;
}
/*
* ima_counts_put - decrement file counts
*
* File counts are incremented in ima_path_check. On file open
* error, such as ETXTBSY, decrement the counts to prevent
* unnecessary imbalance messages.
*/
void ima_counts_put(struct path *path, int mask)
{
struct inode *inode = path->dentry->d_inode;
struct ima_iint_cache *iint;
/* The inode may already have been freed, freeing the iint
* with it. Verify the inode is not NULL before dereferencing
* it.
*/
if (!ima_initialized || !inode || !S_ISREG(inode->i_mode))
return;
iint = ima_iint_find_insert_get(inode);
if (!iint)
return;
mutex_lock(&iint->mutex);
iint->opencount--;
if ((mask & MAY_WRITE) || (mask == 0))
iint->writecount--;
else if (mask & (MAY_READ | MAY_EXEC))
iint->readcount--;
mutex_unlock(&iint->mutex);
kref_put(&iint->refcount, iint_free);
}
/*
* ima_counts_get - increment file counts
*
* - for IPC shm and shmat file.
* - for nfsd exported files.
*
* Increment the counts for these files to prevent unnecessary
* imbalance messages.
*/
void ima_counts_get(struct file *file)
{
struct inode *inode = file->f_dentry->d_inode;
struct ima_iint_cache *iint;
if (!ima_initialized || !S_ISREG(inode->i_mode))
return;
iint = ima_iint_find_insert_get(inode);
if (!iint)
return;
mutex_lock(&iint->mutex);
iint->opencount++;
if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
iint->readcount++;
if (file->f_mode & FMODE_WRITE)
iint->writecount++;
mutex_unlock(&iint->mutex);
kref_put(&iint->refcount, iint_free);
}
EXPORT_SYMBOL_GPL(ima_counts_get);
/**
* 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.
*
* Return 0 on success, an error code on failure.
* (Based on the results of appraise_measurement().)
*/
int ima_file_mmap(struct file *file, unsigned long prot)
{
int rc;
if (!file)
return 0;
if (prot & PROT_EXEC)
rc = process_measurement(file, file->f_dentry->d_name.name,
MAY_EXEC, FILE_MMAP);
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.
*
* Return 0 on success, an error code on failure.
* (Based on the results of appraise_measurement().)
*/
int ima_bprm_check(struct linux_binprm *bprm)
{
int rc;
rc = process_measurement(bprm->file, bprm->filename,
MAY_EXEC, BPRM_CHECK);
return 0;
}
static int __init init_ima(void)
{
int error;
ima_iintcache_init();
error = ima_init();
ima_initialized = 1;
return error;
}
static void __exit cleanup_ima(void)
{
ima_cleanup();
}
late_initcall(init_ima); /* Start IMA after the TPM is available */
MODULE_DESCRIPTION("Integrity Measurement Architecture");
MODULE_LICENSE("GPL");

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@@ -0,0 +1,436 @@
/*
* Copyright (C) 2008 IBM Corporation
* Author: 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.
*
* ima_policy.c
* - initialize default measure policy rules
*
*/
#include <linux/module.h>
#include <linux/list.h>
#include <linux/security.h>
#include <linux/magic.h>
#include <linux/parser.h>
#include "ima.h"
/* flags definitions */
#define IMA_FUNC 0x0001
#define IMA_MASK 0x0002
#define IMA_FSMAGIC 0x0004
#define IMA_UID 0x0008
enum ima_action { UNKNOWN = -1, DONT_MEASURE = 0, MEASURE };
#define MAX_LSM_RULES 6
enum lsm_rule_types { LSM_OBJ_USER, LSM_OBJ_ROLE, LSM_OBJ_TYPE,
LSM_SUBJ_USER, LSM_SUBJ_ROLE, LSM_SUBJ_TYPE
};
struct ima_measure_rule_entry {
struct list_head list;
enum ima_action action;
unsigned int flags;
enum ima_hooks func;
int mask;
unsigned long fsmagic;
uid_t uid;
struct {
void *rule; /* LSM file metadata specific */
int type; /* audit type */
} lsm[MAX_LSM_RULES];
};
/*
* Without LSM specific knowledge, the default policy can only be
* written in terms of .action, .func, .mask, .fsmagic, and .uid
*/
/*
* The minimum rule set to allow for full TCB coverage. Measures all files
* opened or mmap for exec and everything read by root. Dangerous because
* normal users can easily run the machine out of memory simply building
* and running executables.
*/
static struct ima_measure_rule_entry default_rules[] = {
{.action = DONT_MEASURE,.fsmagic = PROC_SUPER_MAGIC,.flags = IMA_FSMAGIC},
{.action = DONT_MEASURE,.fsmagic = SYSFS_MAGIC,.flags = IMA_FSMAGIC},
{.action = DONT_MEASURE,.fsmagic = DEBUGFS_MAGIC,.flags = IMA_FSMAGIC},
{.action = DONT_MEASURE,.fsmagic = TMPFS_MAGIC,.flags = IMA_FSMAGIC},
{.action = DONT_MEASURE,.fsmagic = SECURITYFS_MAGIC,.flags = IMA_FSMAGIC},
{.action = DONT_MEASURE,.fsmagic = SELINUX_MAGIC,.flags = IMA_FSMAGIC},
{.action = MEASURE,.func = FILE_MMAP,.mask = MAY_EXEC,
.flags = IMA_FUNC | IMA_MASK},
{.action = MEASURE,.func = BPRM_CHECK,.mask = MAY_EXEC,
.flags = IMA_FUNC | IMA_MASK},
{.action = MEASURE,.func = PATH_CHECK,.mask = MAY_READ,.uid = 0,
.flags = IMA_FUNC | IMA_MASK | IMA_UID},
};
static LIST_HEAD(measure_default_rules);
static LIST_HEAD(measure_policy_rules);
static struct list_head *ima_measure;
static DEFINE_MUTEX(ima_measure_mutex);
static bool ima_use_tcb __initdata;
static int __init default_policy_setup(char *str)
{
ima_use_tcb = 1;
return 1;
}
__setup("ima_tcb", default_policy_setup);
/**
* ima_match_rules - determine whether an inode matches the measure rule.
* @rule: a pointer to a rule
* @inode: a pointer to an inode
* @func: LIM hook identifier
* @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
*
* Returns true on rule match, false on failure.
*/
static bool ima_match_rules(struct ima_measure_rule_entry *rule,
struct inode *inode, enum ima_hooks func, int mask)
{
struct task_struct *tsk = current;
int i;
if ((rule->flags & IMA_FUNC) && rule->func != func)
return false;
if ((rule->flags & IMA_MASK) && rule->mask != mask)
return false;
if ((rule->flags & IMA_FSMAGIC)
&& rule->fsmagic != inode->i_sb->s_magic)
return false;
if ((rule->flags & IMA_UID) && rule->uid != tsk->cred->uid)
return false;
for (i = 0; i < MAX_LSM_RULES; i++) {
int rc = 0;
u32 osid, sid;
if (!rule->lsm[i].rule)
continue;
switch (i) {
case LSM_OBJ_USER:
case LSM_OBJ_ROLE:
case LSM_OBJ_TYPE:
security_inode_getsecid(inode, &osid);
rc = security_filter_rule_match(osid,
rule->lsm[i].type,
Audit_equal,
rule->lsm[i].rule,
NULL);
break;
case LSM_SUBJ_USER:
case LSM_SUBJ_ROLE:
case LSM_SUBJ_TYPE:
security_task_getsecid(tsk, &sid);
rc = security_filter_rule_match(sid,
rule->lsm[i].type,
Audit_equal,
rule->lsm[i].rule,
NULL);
default:
break;
}
if (!rc)
return false;
}
return true;
}
/**
* ima_match_policy - decision based on LSM and other conditions
* @inode: pointer to an inode for which the policy decision is being made
* @func: IMA hook identifier
* @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
*
* Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
* conditions.
*
* (There is no need for locking when walking the policy list,
* as elements in the list are never deleted, nor does the list
* change.)
*/
int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask)
{
struct ima_measure_rule_entry *entry;
list_for_each_entry(entry, ima_measure, list) {
bool rc;
rc = ima_match_rules(entry, inode, func, mask);
if (rc)
return entry->action;
}
return 0;
}
/**
* ima_init_policy - initialize the default measure rules.
*
* ima_measure points to either the measure_default_rules or the
* the new measure_policy_rules.
*/
void __init ima_init_policy(void)
{
int i, entries;
/* if !ima_use_tcb set entries = 0 so we load NO default rules */
if (ima_use_tcb)
entries = ARRAY_SIZE(default_rules);
else
entries = 0;
for (i = 0; i < entries; i++)
list_add_tail(&default_rules[i].list, &measure_default_rules);
ima_measure = &measure_default_rules;
}
/**
* ima_update_policy - update default_rules with new measure rules
*
* Called on file .release to update the default rules with a complete new
* policy. Once updated, the policy is locked, no additional rules can be
* added to the policy.
*/
void ima_update_policy(void)
{
const char *op = "policy_update";
const char *cause = "already exists";
int result = 1;
int audit_info = 0;
if (ima_measure == &measure_default_rules) {
ima_measure = &measure_policy_rules;
cause = "complete";
result = 0;
}
integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
NULL, op, cause, result, audit_info);
}
enum {
Opt_err = -1,
Opt_measure = 1, Opt_dont_measure,
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_uid
};
static match_table_t policy_tokens = {
{Opt_measure, "measure"},
{Opt_dont_measure, "dont_measure"},
{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_uid, "uid=%s"},
{Opt_err, NULL}
};
static int ima_lsm_rule_init(struct ima_measure_rule_entry *entry,
char *args, int lsm_rule, int audit_type)
{
int result;
entry->lsm[lsm_rule].type = audit_type;
result = security_filter_rule_init(entry->lsm[lsm_rule].type,
Audit_equal, args,
&entry->lsm[lsm_rule].rule);
if (!entry->lsm[lsm_rule].rule)
return -EINVAL;
return result;
}
static int ima_parse_rule(char *rule, struct ima_measure_rule_entry *entry)
{
struct audit_buffer *ab;
char *p;
int result = 0;
ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_INTEGRITY_RULE);
entry->action = -1;
while ((p = strsep(&rule, " \n")) != NULL) {
substring_t args[MAX_OPT_ARGS];
int token;
unsigned long lnum;
if (result < 0)
break;
if (!*p)
continue;
token = match_token(p, policy_tokens, args);
switch (token) {
case Opt_measure:
audit_log_format(ab, "%s ", "measure");
entry->action = MEASURE;
break;
case Opt_dont_measure:
audit_log_format(ab, "%s ", "dont_measure");
entry->action = DONT_MEASURE;
break;
case Opt_func:
audit_log_format(ab, "func=%s ", args[0].from);
if (strcmp(args[0].from, "PATH_CHECK") == 0)
entry->func = PATH_CHECK;
else if (strcmp(args[0].from, "FILE_MMAP") == 0)
entry->func = FILE_MMAP;
else if (strcmp(args[0].from, "BPRM_CHECK") == 0)
entry->func = BPRM_CHECK;
else
result = -EINVAL;
if (!result)
entry->flags |= IMA_FUNC;
break;
case Opt_mask:
audit_log_format(ab, "mask=%s ", args[0].from);
if ((strcmp(args[0].from, "MAY_EXEC")) == 0)
entry->mask = MAY_EXEC;
else if (strcmp(args[0].from, "MAY_WRITE") == 0)
entry->mask = MAY_WRITE;
else if (strcmp(args[0].from, "MAY_READ") == 0)
entry->mask = MAY_READ;
else if (strcmp(args[0].from, "MAY_APPEND") == 0)
entry->mask = MAY_APPEND;
else
result = -EINVAL;
if (!result)
entry->flags |= IMA_MASK;
break;
case Opt_fsmagic:
audit_log_format(ab, "fsmagic=%s ", args[0].from);
result = strict_strtoul(args[0].from, 16,
&entry->fsmagic);
if (!result)
entry->flags |= IMA_FSMAGIC;
break;
case Opt_uid:
audit_log_format(ab, "uid=%s ", args[0].from);
result = strict_strtoul(args[0].from, 10, &lnum);
if (!result) {
entry->uid = (uid_t) lnum;
if (entry->uid != lnum)
result = -EINVAL;
else
entry->flags |= IMA_UID;
}
break;
case Opt_obj_user:
audit_log_format(ab, "obj_user=%s ", args[0].from);
result = ima_lsm_rule_init(entry, args[0].from,
LSM_OBJ_USER,
AUDIT_OBJ_USER);
break;
case Opt_obj_role:
audit_log_format(ab, "obj_role=%s ", args[0].from);
result = ima_lsm_rule_init(entry, args[0].from,
LSM_OBJ_ROLE,
AUDIT_OBJ_ROLE);
break;
case Opt_obj_type:
audit_log_format(ab, "obj_type=%s ", args[0].from);
result = ima_lsm_rule_init(entry, args[0].from,
LSM_OBJ_TYPE,
AUDIT_OBJ_TYPE);
break;
case Opt_subj_user:
audit_log_format(ab, "subj_user=%s ", args[0].from);
result = ima_lsm_rule_init(entry, args[0].from,
LSM_SUBJ_USER,
AUDIT_SUBJ_USER);
break;
case Opt_subj_role:
audit_log_format(ab, "subj_role=%s ", args[0].from);
result = ima_lsm_rule_init(entry, args[0].from,
LSM_SUBJ_ROLE,
AUDIT_SUBJ_ROLE);
break;
case Opt_subj_type:
audit_log_format(ab, "subj_type=%s ", args[0].from);
result = ima_lsm_rule_init(entry, args[0].from,
LSM_SUBJ_TYPE,
AUDIT_SUBJ_TYPE);
break;
case Opt_err:
audit_log_format(ab, "UNKNOWN=%s ", p);
break;
}
}
if (entry->action == UNKNOWN)
result = -EINVAL;
audit_log_format(ab, "res=%d", !result ? 0 : 1);
audit_log_end(ab);
return result;
}
/**
* ima_parse_add_rule - add a rule to measure_policy_rules
* @rule - ima measurement policy rule
*
* Uses a mutex to protect the policy list from multiple concurrent writers.
* Returns 0 on success, an error code on failure.
*/
int ima_parse_add_rule(char *rule)
{
const char *op = "update_policy";
struct ima_measure_rule_entry *entry;
int result = 0;
int audit_info = 0;
/* Prevent installed policy from changing */
if (ima_measure != &measure_default_rules) {
integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
NULL, op, "already exists",
-EACCES, audit_info);
return -EACCES;
}
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(rule, entry);
if (!result) {
mutex_lock(&ima_measure_mutex);
list_add_tail(&entry->list, &measure_policy_rules);
mutex_unlock(&ima_measure_mutex);
} else {
kfree(entry);
integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
NULL, op, "invalid policy", result,
audit_info);
}
return result;
}
/* ima_delete_rules called to cleanup invalid policy */
void ima_delete_rules(void)
{
struct ima_measure_rule_entry *entry, *tmp;
mutex_lock(&ima_measure_mutex);
list_for_each_entry_safe(entry, tmp, &measure_policy_rules, list) {
list_del(&entry->list);
kfree(entry);
}
mutex_unlock(&ima_measure_mutex);
}

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@@ -0,0 +1,141 @@
/*
* Copyright (C) 2005,2006,2007,2008 IBM Corporation
*
* Authors:
* Serge Hallyn <serue@us.ibm.com>
* Reiner Sailer <sailer@watson.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_queue.c
* Implements queues that store template measurements and
* maintains aggregate over the stored measurements
* in the pre-configured TPM PCR (if available).
* The measurement list is append-only. No entry is
* ever removed or changed during the boot-cycle.
*/
#include <linux/module.h>
#include <linux/rculist.h>
#include "ima.h"
LIST_HEAD(ima_measurements); /* list of all measurements */
/* key: inode (before secure-hashing a file) */
struct ima_h_table ima_htable = {
.len = ATOMIC_LONG_INIT(0),
.violations = ATOMIC_LONG_INIT(0),
.queue[0 ... IMA_MEASURE_HTABLE_SIZE - 1] = HLIST_HEAD_INIT
};
/* mutex protects atomicity of extending measurement list
* and extending the TPM PCR aggregate. Since tpm_extend can take
* long (and the tpm driver uses a mutex), we can't use the spinlock.
*/
static DEFINE_MUTEX(ima_extend_list_mutex);
/* lookup up the digest value in the hash table, and return the entry */
static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value)
{
struct ima_queue_entry *qe, *ret = NULL;
unsigned int key;
struct hlist_node *pos;
int rc;
key = ima_hash_key(digest_value);
rcu_read_lock();
hlist_for_each_entry_rcu(qe, pos, &ima_htable.queue[key], hnext) {
rc = memcmp(qe->entry->digest, digest_value, IMA_DIGEST_SIZE);
if (rc == 0) {
ret = qe;
break;
}
}
rcu_read_unlock();
return ret;
}
/* ima_add_template_entry helper function:
* - Add template entry to measurement list and hash table.
*
* (Called with ima_extend_list_mutex held.)
*/
static int ima_add_digest_entry(struct ima_template_entry *entry)
{
struct ima_queue_entry *qe;
unsigned int key;
qe = kmalloc(sizeof(*qe), GFP_KERNEL);
if (qe == NULL) {
pr_err("OUT OF MEMORY ERROR creating queue entry.\n");
return -ENOMEM;
}
qe->entry = entry;
INIT_LIST_HEAD(&qe->later);
list_add_tail_rcu(&qe->later, &ima_measurements);
atomic_long_inc(&ima_htable.len);
key = ima_hash_key(entry->digest);
hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]);
return 0;
}
static int ima_pcr_extend(const u8 *hash)
{
int result = 0;
if (!ima_used_chip)
return result;
result = tpm_pcr_extend(TPM_ANY_NUM, CONFIG_IMA_MEASURE_PCR_IDX, hash);
if (result != 0)
pr_err("Error Communicating to TPM chip\n");
return result;
}
/* Add template entry to the measurement list and hash table,
* and extend the pcr.
*/
int ima_add_template_entry(struct ima_template_entry *entry, int violation,
const char *op, struct inode *inode)
{
u8 digest[IMA_DIGEST_SIZE];
const char *audit_cause = "hash_added";
int audit_info = 1;
int result = 0;
mutex_lock(&ima_extend_list_mutex);
if (!violation) {
memcpy(digest, entry->digest, sizeof digest);
if (ima_lookup_digest_entry(digest)) {
audit_cause = "hash_exists";
goto out;
}
}
result = ima_add_digest_entry(entry);
if (result < 0) {
audit_cause = "ENOMEM";
audit_info = 0;
goto out;
}
if (violation) /* invalidate pcr */
memset(digest, 0xff, sizeof digest);
result = ima_pcr_extend(digest);
if (result != 0) {
audit_cause = "TPM error";
audit_info = 0;
}
out:
mutex_unlock(&ima_extend_list_mutex);
integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode,
entry->template.file_name,
op, audit_cause, result, audit_info);
return result;
}