mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-28 20:02:17 +00:00
![Linus Torvalds](/assets/img/avatar_default.png)
Pull integrity updates from Mimi Zohar: "Bug fixes, code clean up, and new features: - IMA policy rules can be defined in terms of LSM labels, making the IMA policy dependent on LSM policy label changes, in particular LSM label deletions. The new environment, in which IMA-appraisal is being used, frequently updates the LSM policy and permits LSM label deletions. - Prevent an mmap'ed shared file opened for write from also being mmap'ed execute. In the long term, making this and other similar changes at the VFS layer would be preferable. - The IMA per policy rule template format support is needed for a couple of new/proposed features (eg. kexec boot command line measurement, appended signatures, and VFS provided file hashes). - Other than the "boot-aggregate" record in the IMA measuremeent list, all other measurements are of file data. Measuring and storing the kexec boot command line in the IMA measurement list is the first buffer based measurement included in the measurement list" * 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: integrity: Introduce struct evm_xattr ima: Update MAX_TEMPLATE_NAME_LEN to fit largest reasonable definition KEXEC: Call ima_kexec_cmdline to measure the boot command line args IMA: Define a new template field buf IMA: Define a new hook to measure the kexec boot command line arguments IMA: support for per policy rule template formats integrity: Fix __integrity_init_keyring() section mismatch ima: Use designated initializers for struct ima_event_data ima: use the lsm policy update notifier LSM: switch to blocking policy update notifiers x86/ima: fix the Kconfig dependency for IMA_ARCH_POLICY ima: Make arch_policy_entry static ima: prevent a file already mmap'ed write to be mmap'ed execute x86/ima: check EFI SetupMode too
437 lines
11 KiB
C
437 lines
11 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Copyright (C) 2013 Politecnico di Torino, Italy
|
|
* TORSEC group -- http://security.polito.it
|
|
*
|
|
* Author: Roberto Sassu <roberto.sassu@polito.it>
|
|
*
|
|
* File: ima_template.c
|
|
* Helpers to manage template descriptors.
|
|
*/
|
|
|
|
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
|
|
|
#include <linux/rculist.h>
|
|
#include "ima.h"
|
|
#include "ima_template_lib.h"
|
|
|
|
enum header_fields { HDR_PCR, HDR_DIGEST, HDR_TEMPLATE_NAME,
|
|
HDR_TEMPLATE_DATA, HDR__LAST };
|
|
|
|
static struct ima_template_desc builtin_templates[] = {
|
|
{.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT},
|
|
{.name = "ima-ng", .fmt = "d-ng|n-ng"},
|
|
{.name = "ima-sig", .fmt = "d-ng|n-ng|sig"},
|
|
{.name = "ima-buf", .fmt = "d-ng|n-ng|buf"},
|
|
{.name = "", .fmt = ""}, /* placeholder for a custom format */
|
|
};
|
|
|
|
static LIST_HEAD(defined_templates);
|
|
static DEFINE_SPINLOCK(template_list);
|
|
|
|
static const struct ima_template_field supported_fields[] = {
|
|
{.field_id = "d", .field_init = ima_eventdigest_init,
|
|
.field_show = ima_show_template_digest},
|
|
{.field_id = "n", .field_init = ima_eventname_init,
|
|
.field_show = ima_show_template_string},
|
|
{.field_id = "d-ng", .field_init = ima_eventdigest_ng_init,
|
|
.field_show = ima_show_template_digest_ng},
|
|
{.field_id = "n-ng", .field_init = ima_eventname_ng_init,
|
|
.field_show = ima_show_template_string},
|
|
{.field_id = "sig", .field_init = ima_eventsig_init,
|
|
.field_show = ima_show_template_sig},
|
|
{.field_id = "buf", .field_init = ima_eventbuf_init,
|
|
.field_show = ima_show_template_buf},
|
|
};
|
|
|
|
/*
|
|
* Used when restoring measurements carried over from a kexec. 'd' and 'n' don't
|
|
* need to be accounted for since they shouldn't be defined in the same template
|
|
* description as 'd-ng' and 'n-ng' respectively.
|
|
*/
|
|
#define MAX_TEMPLATE_NAME_LEN sizeof("d-ng|n-ng|sig|buf")
|
|
|
|
static struct ima_template_desc *ima_template;
|
|
|
|
static int __init ima_template_setup(char *str)
|
|
{
|
|
struct ima_template_desc *template_desc;
|
|
int template_len = strlen(str);
|
|
|
|
if (ima_template)
|
|
return 1;
|
|
|
|
ima_init_template_list();
|
|
|
|
/*
|
|
* Verify that a template with the supplied name exists.
|
|
* If not, use CONFIG_IMA_DEFAULT_TEMPLATE.
|
|
*/
|
|
template_desc = lookup_template_desc(str);
|
|
if (!template_desc) {
|
|
pr_err("template %s not found, using %s\n",
|
|
str, CONFIG_IMA_DEFAULT_TEMPLATE);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Verify whether the current hash algorithm is supported
|
|
* by the 'ima' template.
|
|
*/
|
|
if (template_len == 3 && strcmp(str, IMA_TEMPLATE_IMA_NAME) == 0 &&
|
|
ima_hash_algo != HASH_ALGO_SHA1 && ima_hash_algo != HASH_ALGO_MD5) {
|
|
pr_err("template does not support hash alg\n");
|
|
return 1;
|
|
}
|
|
|
|
ima_template = template_desc;
|
|
return 1;
|
|
}
|
|
__setup("ima_template=", ima_template_setup);
|
|
|
|
static int __init ima_template_fmt_setup(char *str)
|
|
{
|
|
int num_templates = ARRAY_SIZE(builtin_templates);
|
|
|
|
if (ima_template)
|
|
return 1;
|
|
|
|
if (template_desc_init_fields(str, NULL, NULL) < 0) {
|
|
pr_err("format string '%s' not valid, using template %s\n",
|
|
str, CONFIG_IMA_DEFAULT_TEMPLATE);
|
|
return 1;
|
|
}
|
|
|
|
builtin_templates[num_templates - 1].fmt = str;
|
|
ima_template = builtin_templates + num_templates - 1;
|
|
|
|
return 1;
|
|
}
|
|
__setup("ima_template_fmt=", ima_template_fmt_setup);
|
|
|
|
struct ima_template_desc *lookup_template_desc(const char *name)
|
|
{
|
|
struct ima_template_desc *template_desc;
|
|
int found = 0;
|
|
|
|
rcu_read_lock();
|
|
list_for_each_entry_rcu(template_desc, &defined_templates, list) {
|
|
if ((strcmp(template_desc->name, name) == 0) ||
|
|
(strcmp(template_desc->fmt, name) == 0)) {
|
|
found = 1;
|
|
break;
|
|
}
|
|
}
|
|
rcu_read_unlock();
|
|
return found ? template_desc : NULL;
|
|
}
|
|
|
|
static const struct ima_template_field *
|
|
lookup_template_field(const char *field_id)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(supported_fields); i++)
|
|
if (strncmp(supported_fields[i].field_id, field_id,
|
|
IMA_TEMPLATE_FIELD_ID_MAX_LEN) == 0)
|
|
return &supported_fields[i];
|
|
return NULL;
|
|
}
|
|
|
|
static int template_fmt_size(const char *template_fmt)
|
|
{
|
|
char c;
|
|
int template_fmt_len = strlen(template_fmt);
|
|
int i = 0, j = 0;
|
|
|
|
while (i < template_fmt_len) {
|
|
c = template_fmt[i];
|
|
if (c == '|')
|
|
j++;
|
|
i++;
|
|
}
|
|
|
|
return j + 1;
|
|
}
|
|
|
|
int template_desc_init_fields(const char *template_fmt,
|
|
const struct ima_template_field ***fields,
|
|
int *num_fields)
|
|
{
|
|
const char *template_fmt_ptr;
|
|
const struct ima_template_field *found_fields[IMA_TEMPLATE_NUM_FIELDS_MAX];
|
|
int template_num_fields;
|
|
int i, len;
|
|
|
|
if (num_fields && *num_fields > 0) /* already initialized? */
|
|
return 0;
|
|
|
|
template_num_fields = template_fmt_size(template_fmt);
|
|
|
|
if (template_num_fields > IMA_TEMPLATE_NUM_FIELDS_MAX) {
|
|
pr_err("format string '%s' contains too many fields\n",
|
|
template_fmt);
|
|
return -EINVAL;
|
|
}
|
|
|
|
for (i = 0, template_fmt_ptr = template_fmt; i < template_num_fields;
|
|
i++, template_fmt_ptr += len + 1) {
|
|
char tmp_field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN + 1];
|
|
|
|
len = strchrnul(template_fmt_ptr, '|') - template_fmt_ptr;
|
|
if (len == 0 || len > IMA_TEMPLATE_FIELD_ID_MAX_LEN) {
|
|
pr_err("Invalid field with length %d\n", len);
|
|
return -EINVAL;
|
|
}
|
|
|
|
memcpy(tmp_field_id, template_fmt_ptr, len);
|
|
tmp_field_id[len] = '\0';
|
|
found_fields[i] = lookup_template_field(tmp_field_id);
|
|
if (!found_fields[i]) {
|
|
pr_err("field '%s' not found\n", tmp_field_id);
|
|
return -ENOENT;
|
|
}
|
|
}
|
|
|
|
if (fields && num_fields) {
|
|
*fields = kmalloc_array(i, sizeof(*fields), GFP_KERNEL);
|
|
if (*fields == NULL)
|
|
return -ENOMEM;
|
|
|
|
memcpy(*fields, found_fields, i * sizeof(*fields));
|
|
*num_fields = i;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void ima_init_template_list(void)
|
|
{
|
|
int i;
|
|
|
|
if (!list_empty(&defined_templates))
|
|
return;
|
|
|
|
spin_lock(&template_list);
|
|
for (i = 0; i < ARRAY_SIZE(builtin_templates); i++) {
|
|
list_add_tail_rcu(&builtin_templates[i].list,
|
|
&defined_templates);
|
|
}
|
|
spin_unlock(&template_list);
|
|
}
|
|
|
|
struct ima_template_desc *ima_template_desc_current(void)
|
|
{
|
|
if (!ima_template) {
|
|
ima_init_template_list();
|
|
ima_template =
|
|
lookup_template_desc(CONFIG_IMA_DEFAULT_TEMPLATE);
|
|
}
|
|
return ima_template;
|
|
}
|
|
|
|
int __init ima_init_template(void)
|
|
{
|
|
struct ima_template_desc *template = ima_template_desc_current();
|
|
int result;
|
|
|
|
result = template_desc_init_fields(template->fmt,
|
|
&(template->fields),
|
|
&(template->num_fields));
|
|
if (result < 0)
|
|
pr_err("template %s init failed, result: %d\n",
|
|
(strlen(template->name) ?
|
|
template->name : template->fmt), result);
|
|
|
|
return result;
|
|
}
|
|
|
|
static struct ima_template_desc *restore_template_fmt(char *template_name)
|
|
{
|
|
struct ima_template_desc *template_desc = NULL;
|
|
int ret;
|
|
|
|
ret = template_desc_init_fields(template_name, NULL, NULL);
|
|
if (ret < 0) {
|
|
pr_err("attempting to initialize the template \"%s\" failed\n",
|
|
template_name);
|
|
goto out;
|
|
}
|
|
|
|
template_desc = kzalloc(sizeof(*template_desc), GFP_KERNEL);
|
|
if (!template_desc)
|
|
goto out;
|
|
|
|
template_desc->name = "";
|
|
template_desc->fmt = kstrdup(template_name, GFP_KERNEL);
|
|
if (!template_desc->fmt)
|
|
goto out;
|
|
|
|
spin_lock(&template_list);
|
|
list_add_tail_rcu(&template_desc->list, &defined_templates);
|
|
spin_unlock(&template_list);
|
|
out:
|
|
return template_desc;
|
|
}
|
|
|
|
static int ima_restore_template_data(struct ima_template_desc *template_desc,
|
|
void *template_data,
|
|
int template_data_size,
|
|
struct ima_template_entry **entry)
|
|
{
|
|
int ret = 0;
|
|
int i;
|
|
|
|
*entry = kzalloc(sizeof(**entry) +
|
|
template_desc->num_fields * sizeof(struct ima_field_data),
|
|
GFP_NOFS);
|
|
if (!*entry)
|
|
return -ENOMEM;
|
|
|
|
ret = ima_parse_buf(template_data, template_data + template_data_size,
|
|
NULL, template_desc->num_fields,
|
|
(*entry)->template_data, NULL, NULL,
|
|
ENFORCE_FIELDS | ENFORCE_BUFEND, "template data");
|
|
if (ret < 0) {
|
|
kfree(*entry);
|
|
return ret;
|
|
}
|
|
|
|
(*entry)->template_desc = template_desc;
|
|
for (i = 0; i < template_desc->num_fields; i++) {
|
|
struct ima_field_data *field_data = &(*entry)->template_data[i];
|
|
u8 *data = field_data->data;
|
|
|
|
(*entry)->template_data[i].data =
|
|
kzalloc(field_data->len + 1, GFP_KERNEL);
|
|
if (!(*entry)->template_data[i].data) {
|
|
ret = -ENOMEM;
|
|
break;
|
|
}
|
|
memcpy((*entry)->template_data[i].data, data, field_data->len);
|
|
(*entry)->template_data_len += sizeof(field_data->len);
|
|
(*entry)->template_data_len += field_data->len;
|
|
}
|
|
|
|
if (ret < 0) {
|
|
ima_free_template_entry(*entry);
|
|
*entry = NULL;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/* Restore the serialized binary measurement list without extending PCRs. */
|
|
int ima_restore_measurement_list(loff_t size, void *buf)
|
|
{
|
|
char template_name[MAX_TEMPLATE_NAME_LEN];
|
|
|
|
struct ima_kexec_hdr *khdr = buf;
|
|
struct ima_field_data hdr[HDR__LAST] = {
|
|
[HDR_PCR] = {.len = sizeof(u32)},
|
|
[HDR_DIGEST] = {.len = TPM_DIGEST_SIZE},
|
|
};
|
|
|
|
void *bufp = buf + sizeof(*khdr);
|
|
void *bufendp;
|
|
struct ima_template_entry *entry;
|
|
struct ima_template_desc *template_desc;
|
|
DECLARE_BITMAP(hdr_mask, HDR__LAST);
|
|
unsigned long count = 0;
|
|
int ret = 0;
|
|
|
|
if (!buf || size < sizeof(*khdr))
|
|
return 0;
|
|
|
|
if (ima_canonical_fmt) {
|
|
khdr->version = le16_to_cpu(khdr->version);
|
|
khdr->count = le64_to_cpu(khdr->count);
|
|
khdr->buffer_size = le64_to_cpu(khdr->buffer_size);
|
|
}
|
|
|
|
if (khdr->version != 1) {
|
|
pr_err("attempting to restore a incompatible measurement list");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (khdr->count > ULONG_MAX - 1) {
|
|
pr_err("attempting to restore too many measurements");
|
|
return -EINVAL;
|
|
}
|
|
|
|
bitmap_zero(hdr_mask, HDR__LAST);
|
|
bitmap_set(hdr_mask, HDR_PCR, 1);
|
|
bitmap_set(hdr_mask, HDR_DIGEST, 1);
|
|
|
|
/*
|
|
* ima kexec buffer prefix: version, buffer size, count
|
|
* v1 format: pcr, digest, template-name-len, template-name,
|
|
* template-data-size, template-data
|
|
*/
|
|
bufendp = buf + khdr->buffer_size;
|
|
while ((bufp < bufendp) && (count++ < khdr->count)) {
|
|
int enforce_mask = ENFORCE_FIELDS;
|
|
|
|
enforce_mask |= (count == khdr->count) ? ENFORCE_BUFEND : 0;
|
|
ret = ima_parse_buf(bufp, bufendp, &bufp, HDR__LAST, hdr, NULL,
|
|
hdr_mask, enforce_mask, "entry header");
|
|
if (ret < 0)
|
|
break;
|
|
|
|
if (hdr[HDR_TEMPLATE_NAME].len >= MAX_TEMPLATE_NAME_LEN) {
|
|
pr_err("attempting to restore a template name that is too long\n");
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
/* template name is not null terminated */
|
|
memcpy(template_name, hdr[HDR_TEMPLATE_NAME].data,
|
|
hdr[HDR_TEMPLATE_NAME].len);
|
|
template_name[hdr[HDR_TEMPLATE_NAME].len] = 0;
|
|
|
|
if (strcmp(template_name, "ima") == 0) {
|
|
pr_err("attempting to restore an unsupported template \"%s\" failed\n",
|
|
template_name);
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
template_desc = lookup_template_desc(template_name);
|
|
if (!template_desc) {
|
|
template_desc = restore_template_fmt(template_name);
|
|
if (!template_desc)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Only the running system's template format is initialized
|
|
* on boot. As needed, initialize the other template formats.
|
|
*/
|
|
ret = template_desc_init_fields(template_desc->fmt,
|
|
&(template_desc->fields),
|
|
&(template_desc->num_fields));
|
|
if (ret < 0) {
|
|
pr_err("attempting to restore the template fmt \"%s\" failed\n",
|
|
template_desc->fmt);
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
|
|
ret = ima_restore_template_data(template_desc,
|
|
hdr[HDR_TEMPLATE_DATA].data,
|
|
hdr[HDR_TEMPLATE_DATA].len,
|
|
&entry);
|
|
if (ret < 0)
|
|
break;
|
|
|
|
memcpy(entry->digest, hdr[HDR_DIGEST].data,
|
|
hdr[HDR_DIGEST].len);
|
|
entry->pcr = !ima_canonical_fmt ? *(hdr[HDR_PCR].data) :
|
|
le32_to_cpu(*(hdr[HDR_PCR].data));
|
|
ret = ima_restore_measurement_entry(entry);
|
|
if (ret < 0)
|
|
break;
|
|
|
|
}
|
|
return ret;
|
|
}
|