Commit d643a990 authored by Linus Torvalds's avatar Linus Torvalds

Merge tag 'integrity-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity

Pull IMA updates from Mimi Zohar:
 "New is IMA support for measuring kernel critical data, as per usual
  based on policy. The first example measures the in memory SELinux
  policy. The second example measures the kernel version.

  In addition are four bug fixes to address memory leaks and a missing
  'static' function declaration"

* tag 'integrity-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
  integrity: Make function integrity_add_key() static
  ima: Free IMA measurement buffer after kexec syscall
  ima: Free IMA measurement buffer on error
  IMA: Measure kernel version in early boot
  selinux: include a consumer of the new IMA critical data hook
  IMA: define a builtin critical data measurement policy
  IMA: extend critical data hook to limit the measurement based on a label
  IMA: limit critical data measurement based on a label
  IMA: add policy rule to measure critical data
  IMA: define a hook to measure kernel integrity critical data
  IMA: add support to measure buffer data hash
  IMA: generalize keyring specific measurement constructs
  evm: Fix memleak in init_desc
parents 23b6ba45 f6692213
......@@ -32,7 +32,7 @@ Description:
func:= [BPRM_CHECK][MMAP_CHECK][CREDS_CHECK][FILE_CHECK]MODULE_CHECK]
[FIRMWARE_CHECK]
[KEXEC_KERNEL_CHECK] [KEXEC_INITRAMFS_CHECK]
[KEXEC_CMDLINE] [KEY_CHECK]
[KEXEC_CMDLINE] [KEY_CHECK] [CRITICAL_DATA]
mask:= [[^]MAY_READ] [[^]MAY_WRITE] [[^]MAY_APPEND]
[[^]MAY_EXEC]
fsmagic:= hex value
......@@ -52,6 +52,9 @@ Description:
template:= name of a defined IMA template type
(eg, ima-ng). Only valid when action is "measure".
pcr:= decimal value
label:= [selinux]|[kernel_info]|[data_label]
data_label:= a unique string used for grouping and limiting critical data.
For example, "selinux" to measure critical data for SELinux.
default policy:
# PROC_SUPER_MAGIC
......
......@@ -1747,7 +1747,7 @@
ima_policy= [IMA]
The builtin policies to load during IMA setup.
Format: "tcb | appraise_tcb | secure_boot |
fail_securely"
fail_securely | critical_data"
The "tcb" policy measures all programs exec'd, files
mmap'd for exec, and all files opened with the read
......@@ -1766,6 +1766,9 @@
filesystems with the SB_I_UNVERIFIABLE_SIGNATURE
flag.
The "critical_data" policy measures kernel integrity
critical data.
ima_tcb [IMA] Deprecated. Use ima_policy= instead.
Load a policy which meets the needs of the Trusted
Computing Base. This means IMA will measure all
......
......@@ -31,6 +31,10 @@ extern void ima_post_path_mknod(struct dentry *dentry);
extern int ima_file_hash(struct file *file, char *buf, size_t buf_size);
extern int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size);
extern void ima_kexec_cmdline(int kernel_fd, const void *buf, int size);
extern void ima_measure_critical_data(const char *event_label,
const char *event_name,
const void *buf, size_t buf_len,
bool hash);
#ifdef CONFIG_IMA_APPRAISE_BOOTPARAM
extern void ima_appraise_parse_cmdline(void);
......@@ -128,6 +132,12 @@ static inline int ima_inode_hash(struct inode *inode, char *buf, size_t buf_size
}
static inline void ima_kexec_cmdline(int kernel_fd, const void *buf, int size) {}
static inline void ima_measure_critical_data(const char *event_label,
const char *event_name,
const void *buf, size_t buf_len,
bool hash) {}
#endif /* CONFIG_IMA */
#ifndef CONFIG_IMA_KEXEC
......
......@@ -300,6 +300,11 @@ struct kimage {
/* Information for loading purgatory */
struct purgatory_info purgatory_info;
#endif
#ifdef CONFIG_IMA_KEXEC
/* Virtual address of IMA measurement buffer for kexec syscall */
void *ima_buffer;
#endif
};
/* kexec interface functions */
......
......@@ -166,6 +166,11 @@ void kimage_file_post_load_cleanup(struct kimage *image)
vfree(pi->sechdrs);
pi->sechdrs = NULL;
#ifdef CONFIG_IMA_KEXEC
vfree(image->ima_buffer);
image->ima_buffer = NULL;
#endif /* CONFIG_IMA_KEXEC */
/* See if architecture has anything to cleanup post load */
arch_kimage_file_post_load_cleanup(image);
......
......@@ -143,8 +143,8 @@ int __init integrity_init_keyring(const unsigned int id)
return __integrity_init_keyring(id, perm, restriction);
}
int __init integrity_add_key(const unsigned int id, const void *data,
off_t size, key_perm_t perm)
static int __init integrity_add_key(const unsigned int id, const void *data,
off_t size, key_perm_t perm)
{
key_ref_t key;
int rc = 0;
......
......@@ -73,7 +73,7 @@ static struct shash_desc *init_desc(char type, uint8_t hash_algo)
{
long rc;
const char *algo;
struct crypto_shash **tfm, *tmp_tfm;
struct crypto_shash **tfm, *tmp_tfm = NULL;
struct shash_desc *desc;
if (type == EVM_XATTR_HMAC) {
......@@ -118,13 +118,16 @@ static struct shash_desc *init_desc(char type, uint8_t hash_algo)
alloc:
desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(*tfm),
GFP_KERNEL);
if (!desc)
if (!desc) {
crypto_free_shash(tmp_tfm);
return ERR_PTR(-ENOMEM);
}
desc->tfm = *tfm;
rc = crypto_shash_init(desc);
if (rc) {
crypto_free_shash(tmp_tfm);
kfree(desc);
return ERR_PTR(rc);
}
......
......@@ -201,6 +201,7 @@ static inline unsigned int ima_hash_key(u8 *digest)
hook(POLICY_CHECK, policy) \
hook(KEXEC_CMDLINE, kexec_cmdline) \
hook(KEY_CHECK, key) \
hook(CRITICAL_DATA, critical_data) \
hook(MAX_CHECK, none)
#define __ima_hook_enumify(ENUM, str) ENUM,
......@@ -256,7 +257,7 @@ static inline void ima_process_queued_keys(void) {}
int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
int mask, enum ima_hooks func, int *pcr,
struct ima_template_desc **template_desc,
const char *keyring);
const char *func_data);
int ima_must_measure(struct inode *inode, int mask, enum ima_hooks func);
int ima_collect_measurement(struct integrity_iint_cache *iint,
struct file *file, void *buf, loff_t size,
......@@ -268,7 +269,8 @@ void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
struct ima_template_desc *template_desc);
void process_buffer_measurement(struct inode *inode, const void *buf, int size,
const char *eventname, enum ima_hooks func,
int pcr, const char *keyring);
int pcr, const char *func_data,
bool buf_hash);
void ima_audit_measurement(struct integrity_iint_cache *iint,
const unsigned char *filename);
int ima_alloc_init_template(struct ima_event_data *event_data,
......@@ -284,7 +286,7 @@ const char *ima_d_path(const struct path *path, char **pathbuf, char *filename);
int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
enum ima_hooks func, int mask, int flags, int *pcr,
struct ima_template_desc **template_desc,
const char *keyring);
const char *func_data);
void ima_init_policy(void);
void ima_update_policy(void);
void ima_update_policy_flag(void);
......
......@@ -170,13 +170,13 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
* @func: caller identifier
* @pcr: pointer filled in if matched measure policy sets pcr=
* @template_desc: pointer filled in if matched measure policy sets template=
* @keyring: keyring name used to determine the action
* @func_data: func specific data, may be NULL
*
* The policy is defined in terms of keypairs:
* subj=, obj=, type=, func=, mask=, fsmagic=
* subj,obj, and type: are LSM specific.
* func: FILE_CHECK | BPRM_CHECK | CREDS_CHECK | MMAP_CHECK | MODULE_CHECK
* | KEXEC_CMDLINE | KEY_CHECK
* | KEXEC_CMDLINE | KEY_CHECK | CRITICAL_DATA
* mask: contains the permission mask
* fsmagic: hex value
*
......@@ -186,14 +186,14 @@ void ima_add_violation(struct file *file, const unsigned char *filename,
int ima_get_action(struct inode *inode, const struct cred *cred, u32 secid,
int mask, enum ima_hooks func, int *pcr,
struct ima_template_desc **template_desc,
const char *keyring)
const char *func_data)
{
int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE | IMA_HASH;
flags &= ima_policy_flag;
return ima_match_policy(inode, cred, secid, func, mask, flags, pcr,
template_desc, keyring);
template_desc, func_data);
}
/*
......
......@@ -352,7 +352,7 @@ int ima_check_blacklist(struct integrity_iint_cache *iint,
if ((rc == -EPERM) && (iint->flags & IMA_MEASURE))
process_buffer_measurement(NULL, digest, digestsize,
"blacklisted-hash", NONE,
pcr, NULL);
pcr, NULL, false);
}
return rc;
......
......@@ -60,5 +60,5 @@ void ima_post_key_create_or_update(struct key *keyring, struct key *key,
*/
process_buffer_measurement(NULL, payload, payload_len,
keyring->description, KEY_CHECK, 0,
keyring->description);
keyring->description, false);
}
......@@ -15,6 +15,8 @@
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/ima.h>
#include <generated/utsrelease.h>
#include "ima.h"
......@@ -147,5 +149,8 @@ int __init ima_init(void)
ima_init_key_queue();
ima_measure_critical_data("kernel_info", "kernel_version",
UTS_RELEASE, strlen(UTS_RELEASE), false);
return rc;
}
......@@ -119,6 +119,7 @@ void ima_add_kexec_buffer(struct kimage *image)
ret = kexec_add_buffer(&kbuf);
if (ret) {
pr_err("Error passing over kexec measurement buffer.\n");
vfree(kexec_buffer);
return;
}
......@@ -128,6 +129,8 @@ void ima_add_kexec_buffer(struct kimage *image)
return;
}
image->ima_buffer = kexec_buffer;
pr_debug("kexec measurement buffer for the loaded kernel at 0x%lx.\n",
kbuf.mem);
}
......
......@@ -809,20 +809,22 @@ int ima_post_load_data(char *buf, loff_t size,
}
/*
* process_buffer_measurement - Measure the buffer to ima log.
* process_buffer_measurement - Measure the buffer or the buffer data hash
* @inode: inode associated with the object being measured (NULL for KEY_CHECK)
* @buf: pointer to the buffer that needs to be added to the log.
* @size: size of buffer(in bytes).
* @eventname: event name to be used for the buffer entry.
* @func: IMA hook
* @pcr: pcr to extend the measurement
* @keyring: keyring name to determine the action to be performed
* @func_data: func specific data, may be NULL
* @buf_hash: measure buffer data hash
*
* Based on policy, the buffer is measured into the ima log.
* Based on policy, either the buffer data or buffer data hash is measured
*/
void process_buffer_measurement(struct inode *inode, const void *buf, int size,
const char *eventname, enum ima_hooks func,
int pcr, const char *keyring)
int pcr, const char *func_data,
bool buf_hash)
{
int ret = 0;
const char *audit_cause = "ENOMEM";
......@@ -837,6 +839,8 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size,
struct ima_digest_data hdr;
char digest[IMA_MAX_DIGEST_SIZE];
} hash = {};
char digest_hash[IMA_MAX_DIGEST_SIZE];
int digest_hash_len = hash_digest_size[ima_hash_algo];
int violation = 0;
int action = 0;
u32 secid;
......@@ -861,7 +865,7 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size,
if (func) {
security_task_getsecid(current, &secid);
action = ima_get_action(inode, current_cred(), secid, 0, func,
&pcr, &template, keyring);
&pcr, &template, func_data);
if (!(action & IMA_MEASURE))
return;
}
......@@ -879,13 +883,27 @@ void process_buffer_measurement(struct inode *inode, const void *buf, int size,
goto out;
}
if (buf_hash) {
memcpy(digest_hash, hash.hdr.digest, digest_hash_len);
ret = ima_calc_buffer_hash(digest_hash, digest_hash_len,
iint.ima_hash);
if (ret < 0) {
audit_cause = "hashing_error";
goto out;
}
event_data.buf = digest_hash;
event_data.buf_len = digest_hash_len;
}
ret = ima_alloc_init_template(&event_data, &entry, template);
if (ret < 0) {
audit_cause = "alloc_entry";
goto out;
}
ret = ima_store_template(entry, violation, NULL, buf, pcr);
ret = ima_store_template(entry, violation, NULL, event_data.buf, pcr);
if (ret < 0) {
audit_cause = "store_entry";
ima_free_template_entry(entry);
......@@ -920,10 +938,37 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size)
return;
process_buffer_measurement(file_inode(f.file), buf, size,
"kexec-cmdline", KEXEC_CMDLINE, 0, NULL);
"kexec-cmdline", KEXEC_CMDLINE, 0, NULL,
false);
fdput(f);
}
/**
* ima_measure_critical_data - measure kernel integrity critical data
* @event_label: unique event label for grouping and limiting critical data
* @event_name: event name for the record in the IMA measurement list
* @buf: pointer to buffer data
* @buf_len: length of buffer data (in bytes)
* @hash: measure buffer data hash
*
* Measure data critical to the integrity of the kernel into the IMA log
* and extend the pcr. Examples of critical data could be various data
* structures, policies, and states stored in kernel memory that can
* impact the integrity of the system.
*/
void ima_measure_critical_data(const char *event_label,
const char *event_name,
const void *buf, size_t buf_len,
bool hash)
{
if (!event_name || !event_label || !buf || !buf_len)
return;
process_buffer_measurement(NULL, buf, buf_len, event_name,
CRITICAL_DATA, 0, event_label,
hash);
}
static int __init init_ima(void)
{
int error;
......
......@@ -34,6 +34,7 @@
#define IMA_PCR 0x0100
#define IMA_FSNAME 0x0200
#define IMA_KEYRINGS 0x0400
#define IMA_LABEL 0x0800
#define UNKNOWN 0
#define MEASURE 0x0001 /* same as IMA_MEASURE */
......@@ -85,6 +86,7 @@ struct ima_rule_entry {
} lsm[MAX_LSM_RULES];
char *fsname;
struct ima_rule_opt_list *keyrings; /* Measure keys added to these keyrings */
struct ima_rule_opt_list *label; /* Measure data grouped under this label */
struct ima_template_desc *template;
};
......@@ -204,6 +206,10 @@ static struct ima_rule_entry secure_boot_rules[] __ro_after_init = {
.flags = IMA_FUNC | IMA_DIGSIG_REQUIRED},
};
static struct ima_rule_entry critical_data_rules[] __ro_after_init = {
{.action = MEASURE, .func = CRITICAL_DATA, .flags = IMA_FUNC},
};
/* An array of architecture specific rules */
static struct ima_rule_entry *arch_policy_entry __ro_after_init;
......@@ -226,6 +232,7 @@ __setup("ima_tcb", default_measure_policy_setup);
static bool ima_use_appraise_tcb __initdata;
static bool ima_use_secure_boot __initdata;
static bool ima_use_critical_data __initdata;
static bool ima_fail_unverifiable_sigs __ro_after_init;
static int __init policy_setup(char *str)
{
......@@ -240,6 +247,8 @@ static int __init policy_setup(char *str)
ima_use_appraise_tcb = true;
else if (strcmp(p, "secure_boot") == 0)
ima_use_secure_boot = true;
else if (strcmp(p, "critical_data") == 0)
ima_use_critical_data = true;
else if (strcmp(p, "fail_securely") == 0)
ima_fail_unverifiable_sigs = true;
else
......@@ -453,30 +462,46 @@ int ima_lsm_policy_change(struct notifier_block *nb, unsigned long event,
}
/**
* ima_match_keyring - determine whether the keyring matches the measure rule
* ima_match_rule_data - determine whether func_data matches the policy rule
* @rule: a pointer to a rule
* @keyring: name of the keyring to match against the measure rule
* @func_data: data to match against the measure rule data
* @cred: a pointer to a credentials structure for user validation
*
* Returns true if keyring matches one in the rule, false otherwise.
* Returns true if func_data matches one in the rule, false otherwise.
*/
static bool ima_match_keyring(struct ima_rule_entry *rule,
const char *keyring, const struct cred *cred)
static bool ima_match_rule_data(struct ima_rule_entry *rule,
const char *func_data,
const struct cred *cred)
{
const struct ima_rule_opt_list *opt_list = NULL;
bool matched = false;
size_t i;
if ((rule->flags & IMA_UID) && !rule->uid_op(cred->uid, rule->uid))
return false;
if (!rule->keyrings)
return true;
switch (rule->func) {
case KEY_CHECK:
if (!rule->keyrings)
return true;
opt_list = rule->keyrings;
break;
case CRITICAL_DATA:
if (!rule->label)
return true;
opt_list = rule->label;
break;
default:
return false;
}
if (!keyring)
if (!func_data)
return false;
for (i = 0; i < rule->keyrings->count; i++) {
if (!strcmp(rule->keyrings->items[i], keyring)) {
for (i = 0; i < opt_list->count; i++) {
if (!strcmp(opt_list->items[i], func_data)) {
matched = true;
break;
}
......@@ -493,24 +518,30 @@ static bool ima_match_keyring(struct ima_rule_entry *rule,
* @secid: the secid of the task to be validated
* @func: LIM hook identifier
* @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
* @keyring: keyring name to check in policy for KEY_CHECK func
* @func_data: func specific data, may be NULL
*
* Returns true on rule match, false on failure.
*/
static bool ima_match_rules(struct ima_rule_entry *rule, struct inode *inode,
const struct cred *cred, u32 secid,
enum ima_hooks func, int mask,
const char *keyring)
const char *func_data)
{
int i;
if (func == KEY_CHECK) {
return (rule->flags & IMA_FUNC) && (rule->func == func) &&
ima_match_keyring(rule, keyring, cred);
}
if ((rule->flags & IMA_FUNC) &&
(rule->func != func && func != POST_SETATTR))
return false;
switch (func) {
case KEY_CHECK:
case CRITICAL_DATA:
return ((rule->func == func) &&
ima_match_rule_data(rule, func_data, cred));
default:
break;
}
if ((rule->flags & IMA_MASK) &&
(rule->mask != mask && func != POST_SETATTR))
return false;
......@@ -610,8 +641,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
* @mask: requested action (MAY_READ | MAY_WRITE | MAY_APPEND | MAY_EXEC)
* @pcr: set the pcr to extend
* @template_desc: the template that should be used for this rule
* @keyring: the keyring name, if given, to be used to check in the policy.
* keyring can be NULL if func is anything other than KEY_CHECK.
* @func_data: func specific data, may be NULL
*
* Measure decision based on func/mask/fsmagic and LSM(subj/obj/type)
* conditions.
......@@ -623,7 +653,7 @@ static int get_subaction(struct ima_rule_entry *rule, enum ima_hooks func)
int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
enum ima_hooks func, int mask, int flags, int *pcr,
struct ima_template_desc **template_desc,
const char *keyring)
const char *func_data)
{
struct ima_rule_entry *entry;
int action = 0, actmask = flags | (flags << 1);
......@@ -638,7 +668,7 @@ int ima_match_policy(struct inode *inode, const struct cred *cred, u32 secid,
continue;
if (!ima_match_rules(entry, inode, cred, secid, func, mask,
keyring))
func_data))
continue;
action |= entry->flags & IMA_ACTION_FLAGS;
......@@ -848,6 +878,11 @@ void __init ima_init_policy(void)
ARRAY_SIZE(default_appraise_rules),
IMA_DEFAULT_POLICY);
if (ima_use_critical_data)
add_rules(critical_data_rules,
ARRAY_SIZE(critical_data_rules),
IMA_DEFAULT_POLICY);
ima_update_policy_flag();
}
......@@ -907,7 +942,7 @@ enum {
Opt_uid_lt, Opt_euid_lt, Opt_fowner_lt,
Opt_appraise_type, Opt_appraise_flag,
Opt_permit_directio, Opt_pcr, Opt_template, Opt_keyrings,
Opt_err
Opt_label, Opt_err
};
static const match_table_t policy_tokens = {
......@@ -944,6 +979,7 @@ static const match_table_t policy_tokens = {
{Opt_pcr, "pcr=%s"},
{Opt_template, "template=%s"},
{Opt_keyrings, "keyrings=%s"},
{Opt_label, "label=%s"},
{Opt_err, NULL}
};
......@@ -1106,6 +1142,18 @@ static bool ima_validate_rule(struct ima_rule_entry *entry)
if (ima_rule_contains_lsm_cond(entry))
return false;
break;
case CRITICAL_DATA:
if (entry->action & ~(MEASURE | DONT_MEASURE))
return false;
if (entry->flags & ~(IMA_FUNC | IMA_UID | IMA_PCR |
IMA_LABEL))
return false;
if (ima_rule_contains_lsm_cond(entry))
return false;
break;
default:
return false;
......@@ -1238,6 +1286,8 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
else if (IS_ENABLED(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) &&
strcmp(args[0].from, "KEY_CHECK") == 0)
entry->func = KEY_CHECK;
else if (strcmp(args[0].from, "CRITICAL_DATA") == 0)
entry->func = CRITICAL_DATA;
else
result = -EINVAL;
if (!result)
......@@ -1308,6 +1358,23 @@ static int ima_parse_rule(char *rule, struct ima_rule_entry *entry)
entry->flags |= IMA_KEYRINGS;
break;
case Opt_label:
ima_log_string(ab, "label", args[0].from);
if (entry->label) {
result = -EINVAL;
break;
}
entry->label = ima_alloc_rule_opt_list(args);
if (IS_ERR(entry->label)) {
result = PTR_ERR(entry->label);
entry->label = NULL;
break;
}
entry->flags |= IMA_LABEL;
break;
case Opt_fsuuid:
ima_log_string(ab, "fsuuid", args[0].from);
......@@ -1688,6 +1755,12 @@ int ima_policy_show(struct seq_file *m, void *v)
seq_puts(m, " ");
}
if (entry->flags & IMA_LABEL) {
seq_puts(m, "label=");
ima_show_rule_opt_list(m, entry->label);
seq_puts(m, " ");
}
if (entry->flags & IMA_PCR) {
snprintf(tbuf, sizeof(tbuf), "%d", entry->pcr);
seq_printf(m, pt(Opt_pcr), tbuf);
......
......@@ -162,7 +162,8 @@ void ima_process_queued_keys(void)
entry->payload_len,
entry->keyring_name,
KEY_CHECK, 0,
entry->keyring_name);
entry->keyring_name,
false);
list_del(&entry->list);
ima_free_key_entry(entry);
}
......
......@@ -16,6 +16,8 @@ selinux-$(CONFIG_NETLABEL) += netlabel.o
selinux-$(CONFIG_SECURITY_INFINIBAND) += ibpkey.o
selinux-$(CONFIG_IMA) += ima.o
ccflags-y := -I$(srctree)/security/selinux -I$(srctree)/security/selinux/include
$(addprefix $(obj)/,$(selinux-y)): $(obj)/flask.h
......
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2021 Microsoft Corporation
*
* Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com)
*
* Measure critical data structures maintainted by SELinux
* using IMA subsystem.
*/
#include <linux/vmalloc.h>
#include <linux/ima.h>
#include "security.h"
#include "ima.h"
/*
* selinux_ima_measure_state - Measure hash of the SELinux policy
*
* @state: selinux state struct
*
* NOTE: This function must be called with policy_mutex held.
*/
void selinux_ima_measure_state(struct selinux_state *state)
{
void *policy = NULL;
size_t policy_len;
int rc = 0;
/*
* Measure SELinux policy only after initialization is completed.
*/
if (!selinux_initialized(state))
return;
rc = security_read_state_kernel(state, &policy, &policy_len);
if (rc) {
pr_err("SELinux: %s: failed to read policy %d.\n", __func__, rc);
return;
}
ima_measure_critical_data("selinux", "selinux-policy-hash",
policy, policy_len, true);
vfree(policy);
}
/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Copyright (C) 2021 Microsoft Corporation
*
* Author: Lakshmi Ramasubramanian (nramas@linux.microsoft.com)
*
* Measure critical data structures maintainted by SELinux
* using IMA subsystem.
*/
#ifndef _SELINUX_IMA_H_
#define _SELINUX_IMA_H_
#include "security.h"
#ifdef CONFIG_IMA
extern void selinux_ima_measure_state(struct selinux_state *selinux_state);
#else
static inline void selinux_ima_measure_state(struct selinux_state *selinux_state)
{
}
#endif
#endif /* _SELINUX_IMA_H_ */
......@@ -229,7 +229,8 @@ void selinux_policy_cancel(struct selinux_state *state,
struct selinux_policy *policy);
int security_read_policy(struct selinux_state *state,
void **data, size_t *len);
int security_read_state_kernel(struct selinux_state *state,
void **data, size_t *len);
int security_policycap_supported(struct selinux_state *state,
unsigned int req_cap);
......
......@@ -65,6 +65,7 @@
#include "ebitmap.h"
#include "audit.h"
#include "policycap_names.h"
#include "ima.h"
/* Forward declaration. */
static int context_struct_to_string(struct policydb *policydb,
......@@ -2178,6 +2179,7 @@ static void selinux_notify_policy_change(struct selinux_state *state,
selinux_status_update_policyload(state, seqno);
selinux_netlbl_cache_invalidate();
selinux_xfrm_notify_policyload();
selinux_ima_measure_state(state);
}
void selinux_policy_commit(struct selinux_state *state,
......@@ -3869,8 +3871,33 @@ int security_netlbl_sid_to_secattr(struct selinux_state *state,
}
#endif /* CONFIG_NETLABEL */
/**
* __security_read_policy - read the policy.
* @policy: SELinux policy
* @data: binary policy data
* @len: length of data in bytes
*
*/
static int __security_read_policy(struct selinux_policy *policy,
void *data, size_t *len)
{
int rc;
struct policy_file fp;
fp.data = data;
fp.len = *len;
rc = policydb_write(&policy->policydb, &fp);
if (rc)
return rc;
*len = (unsigned long)fp.data - (unsigned long)data;
return 0;
}
/**
* security_read_policy - read the policy.
* @state: selinux_state
* @data: binary policy data
* @len: length of data in bytes
*
......@@ -3879,8 +3906,6 @@ int security_read_policy(struct selinux_state *state,
void **data, size_t *len)
{
struct selinux_policy *policy;
int rc;
struct policy_file fp;
policy = rcu_dereference_protected(
state->policy, lockdep_is_held(&state->policy_mutex));
......@@ -3892,14 +3917,35 @@ int security_read_policy(struct selinux_state *state,
if (!*data)
return -ENOMEM;
fp.data = *data;
fp.len = *len;
return __security_read_policy(policy, *data, len);
}
rc = policydb_write(&policy->policydb, &fp);
if (rc)
return rc;
/**
* security_read_state_kernel - read the policy.
* @state: selinux_state
* @data: binary policy data
* @len: length of data in bytes
*
* Allocates kernel memory for reading SELinux policy.
* This function is for internal use only and should not
* be used for returning data to user space.
*
* This function must be called with policy_mutex held.
*/
int security_read_state_kernel(struct selinux_state *state,
void **data, size_t *len)
{
struct selinux_policy *policy;
*len = (unsigned long)fp.data - (unsigned long)*data;
return 0;
policy = rcu_dereference_protected(
state->policy, lockdep_is_held(&state->policy_mutex));
if (!policy)
return -EINVAL;
*len = policy->policydb.len;
*data = vmalloc(*len);
if (!*data)
return -ENOMEM;
return __security_read_policy(policy, *data, len);
}
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