2 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
5 * Kylene Hall <kjhall@us.ibm.com>
6 * Reiner Sailer <sailer@us.ibm.com>
7 * Mimi Zohar <zohar@us.ibm.com>
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation, version 2 of the
15 * implemenents security file system for reporting
16 * current measurement list and IMA statistics
18 #include <linux/fcntl.h>
19 #include <linux/slab.h>
20 #include <linux/module.h>
21 #include <linux/seq_file.h>
22 #include <linux/rculist.h>
23 #include <linux/rcupdate.h>
24 #include <linux/parser.h>
25 #include <linux/vmalloc.h>
29 static DEFINE_MUTEX(ima_write_mutex);
31 bool ima_canonical_fmt;
32 static int __init default_canonical_fmt_setup(char *str)
35 ima_canonical_fmt = 1;
39 __setup("ima_canonical_fmt", default_canonical_fmt_setup);
41 static int valid_policy = 1;
43 static ssize_t ima_show_htable_value(char __user *buf, size_t count,
44 loff_t *ppos, atomic_long_t *val)
46 char tmpbuf[32]; /* greater than largest 'long' string value */
49 len = scnprintf(tmpbuf, sizeof(tmpbuf), "%li\n", atomic_long_read(val));
50 return simple_read_from_buffer(buf, count, ppos, tmpbuf, len);
53 static ssize_t ima_show_htable_violations(struct file *filp,
55 size_t count, loff_t *ppos)
57 return ima_show_htable_value(buf, count, ppos, &ima_htable.violations);
60 static const struct file_operations ima_htable_violations_ops = {
61 .read = ima_show_htable_violations,
62 .llseek = generic_file_llseek,
65 static ssize_t ima_show_measurements_count(struct file *filp,
67 size_t count, loff_t *ppos)
69 return ima_show_htable_value(buf, count, ppos, &ima_htable.len);
73 static const struct file_operations ima_measurements_count_ops = {
74 .read = ima_show_measurements_count,
75 .llseek = generic_file_llseek,
78 /* returns pointer to hlist_node */
79 static void *ima_measurements_start(struct seq_file *m, loff_t *pos)
82 struct ima_queue_entry *qe;
84 /* we need a lock since pos could point beyond last element */
86 list_for_each_entry_rcu(qe, &ima_measurements, later) {
96 static void *ima_measurements_next(struct seq_file *m, void *v, loff_t *pos)
98 struct ima_queue_entry *qe = v;
100 /* lock protects when reading beyond last element
101 * against concurrent list-extension
104 qe = list_entry_rcu(qe->later.next, struct ima_queue_entry, later);
108 return (&qe->later == &ima_measurements) ? NULL : qe;
111 static void ima_measurements_stop(struct seq_file *m, void *v)
115 void ima_putc(struct seq_file *m, void *data, int datalen)
118 seq_putc(m, *(char *)data++);
123 * char[20]=template digest
124 * 32bit-le=template name size
125 * char[n]=template name
127 * eventdata[n]=template specific data
129 int ima_measurements_show(struct seq_file *m, void *v)
131 /* the list never shrinks, so we don't need a lock here */
132 struct ima_queue_entry *qe = v;
133 struct ima_template_entry *e;
135 u32 pcr, namelen, template_data_len; /* temporary fields */
136 bool is_ima_template = false;
144 template_name = (e->template_desc->name[0] != '\0') ?
145 e->template_desc->name : e->template_desc->fmt;
149 * PCR used defaults to the same (config option) in
150 * little-endian format, unless set in policy
152 pcr = !ima_canonical_fmt ? e->pcr : cpu_to_le32(e->pcr);
153 ima_putc(m, &pcr, sizeof(e->pcr));
155 /* 2nd: template digest */
156 ima_putc(m, e->digest, TPM_DIGEST_SIZE);
158 /* 3rd: template name size */
159 namelen = !ima_canonical_fmt ? strlen(template_name) :
160 cpu_to_le32(strlen(template_name));
161 ima_putc(m, &namelen, sizeof(namelen));
163 /* 4th: template name */
164 ima_putc(m, template_name, strlen(template_name));
166 /* 5th: template length (except for 'ima' template) */
167 if (strcmp(template_name, IMA_TEMPLATE_IMA_NAME) == 0)
168 is_ima_template = true;
170 if (!is_ima_template) {
171 template_data_len = !ima_canonical_fmt ? e->template_data_len :
172 cpu_to_le32(e->template_data_len);
173 ima_putc(m, &template_data_len, sizeof(e->template_data_len));
176 /* 6th: template specific data */
177 for (i = 0; i < e->template_desc->num_fields; i++) {
178 enum ima_show_type show = IMA_SHOW_BINARY;
179 struct ima_template_field *field = e->template_desc->fields[i];
181 if (is_ima_template && strcmp(field->field_id, "d") == 0)
182 show = IMA_SHOW_BINARY_NO_FIELD_LEN;
183 if (is_ima_template && strcmp(field->field_id, "n") == 0)
184 show = IMA_SHOW_BINARY_OLD_STRING_FMT;
185 field->field_show(m, show, &e->template_data[i]);
190 static const struct seq_operations ima_measurments_seqops = {
191 .start = ima_measurements_start,
192 .next = ima_measurements_next,
193 .stop = ima_measurements_stop,
194 .show = ima_measurements_show
197 static int ima_measurements_open(struct inode *inode, struct file *file)
199 return seq_open(file, &ima_measurments_seqops);
202 static const struct file_operations ima_measurements_ops = {
203 .open = ima_measurements_open,
206 .release = seq_release,
209 void ima_print_digest(struct seq_file *m, u8 *digest, u32 size)
213 for (i = 0; i < size; i++)
214 seq_printf(m, "%02x", *(digest + i));
218 static int ima_ascii_measurements_show(struct seq_file *m, void *v)
220 /* the list never shrinks, so we don't need a lock here */
221 struct ima_queue_entry *qe = v;
222 struct ima_template_entry *e;
231 template_name = (e->template_desc->name[0] != '\0') ?
232 e->template_desc->name : e->template_desc->fmt;
234 /* 1st: PCR used (config option) */
235 seq_printf(m, "%2d ", e->pcr);
237 /* 2nd: SHA1 template hash */
238 ima_print_digest(m, e->digest, TPM_DIGEST_SIZE);
240 /* 3th: template name */
241 seq_printf(m, " %s", template_name);
243 /* 4th: template specific data */
244 for (i = 0; i < e->template_desc->num_fields; i++) {
246 if (e->template_data[i].len == 0)
249 e->template_desc->fields[i]->field_show(m, IMA_SHOW_ASCII,
250 &e->template_data[i]);
256 static const struct seq_operations ima_ascii_measurements_seqops = {
257 .start = ima_measurements_start,
258 .next = ima_measurements_next,
259 .stop = ima_measurements_stop,
260 .show = ima_ascii_measurements_show
263 static int ima_ascii_measurements_open(struct inode *inode, struct file *file)
265 return seq_open(file, &ima_ascii_measurements_seqops);
268 static const struct file_operations ima_ascii_measurements_ops = {
269 .open = ima_ascii_measurements_open,
272 .release = seq_release,
275 static ssize_t ima_read_policy(char *path)
280 int rc, pathlen = strlen(path);
286 strsep(&datap, "\n");
288 rc = kernel_read_file_from_path(path, &data, &size, 0, READING_POLICY);
290 pr_err("Unable to open file: %s (%d)", path, rc);
295 while (size > 0 && (p = strsep(&datap, "\n"))) {
296 pr_debug("rule: %s\n", p);
297 rc = ima_parse_add_rule(p);
312 static ssize_t ima_write_policy(struct file *file, const char __user *buf,
313 size_t datalen, loff_t *ppos)
318 if (datalen >= PAGE_SIZE)
319 datalen = PAGE_SIZE - 1;
321 /* No partial writes. */
326 data = memdup_user_nul(buf, datalen);
328 result = PTR_ERR(data);
332 result = mutex_lock_interruptible(&ima_write_mutex);
336 if (data[0] == '/') {
337 result = ima_read_policy(data);
338 } else if (ima_appraise & IMA_APPRAISE_POLICY) {
339 pr_err("IMA: signed policy file (specified as an absolute pathname) required\n");
340 integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
341 "policy_update", "signed policy required",
345 result = ima_parse_add_rule(data);
347 mutex_unlock(&ima_write_mutex);
357 static struct dentry *ima_dir;
358 static struct dentry *binary_runtime_measurements;
359 static struct dentry *ascii_runtime_measurements;
360 static struct dentry *runtime_measurements_count;
361 static struct dentry *violations;
362 static struct dentry *ima_policy;
368 static unsigned long ima_fs_flags;
370 #ifdef CONFIG_IMA_READ_POLICY
371 static const struct seq_operations ima_policy_seqops = {
372 .start = ima_policy_start,
373 .next = ima_policy_next,
374 .stop = ima_policy_stop,
375 .show = ima_policy_show,
380 * ima_open_policy: sequentialize access to the policy file
382 static int ima_open_policy(struct inode *inode, struct file *filp)
384 if (!(filp->f_flags & O_WRONLY)) {
385 #ifndef CONFIG_IMA_READ_POLICY
388 if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
390 if (!capable(CAP_SYS_ADMIN))
392 return seq_open(filp, &ima_policy_seqops);
395 if (test_and_set_bit(IMA_FS_BUSY, &ima_fs_flags))
401 * ima_release_policy - start using the new measure policy rules.
403 * Initially, ima_measure points to the default policy rules, now
404 * point to the new policy rules, and remove the securityfs policy file,
405 * assuming a valid policy.
407 static int ima_release_policy(struct inode *inode, struct file *file)
409 const char *cause = valid_policy ? "completed" : "failed";
411 if ((file->f_flags & O_ACCMODE) == O_RDONLY)
412 return seq_release(inode, file);
414 if (valid_policy && ima_check_policy() < 0) {
419 pr_info("IMA: policy update %s\n", cause);
420 integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
421 "policy_update", cause, !valid_policy, 0);
426 clear_bit(IMA_FS_BUSY, &ima_fs_flags);
431 #ifndef CONFIG_IMA_WRITE_POLICY
432 securityfs_remove(ima_policy);
435 clear_bit(IMA_FS_BUSY, &ima_fs_flags);
440 static const struct file_operations ima_measure_policy_ops = {
441 .open = ima_open_policy,
442 .write = ima_write_policy,
444 .release = ima_release_policy,
445 .llseek = generic_file_llseek,
448 int __init ima_fs_init(void)
450 ima_dir = securityfs_create_dir("ima", NULL);
454 binary_runtime_measurements =
455 securityfs_create_file("binary_runtime_measurements",
456 S_IRUSR | S_IRGRP, ima_dir, NULL,
457 &ima_measurements_ops);
458 if (IS_ERR(binary_runtime_measurements))
461 ascii_runtime_measurements =
462 securityfs_create_file("ascii_runtime_measurements",
463 S_IRUSR | S_IRGRP, ima_dir, NULL,
464 &ima_ascii_measurements_ops);
465 if (IS_ERR(ascii_runtime_measurements))
468 runtime_measurements_count =
469 securityfs_create_file("runtime_measurements_count",
470 S_IRUSR | S_IRGRP, ima_dir, NULL,
471 &ima_measurements_count_ops);
472 if (IS_ERR(runtime_measurements_count))
476 securityfs_create_file("violations", S_IRUSR | S_IRGRP,
477 ima_dir, NULL, &ima_htable_violations_ops);
478 if (IS_ERR(violations))
481 ima_policy = securityfs_create_file("policy", POLICY_FILE_FLAGS,
483 &ima_measure_policy_ops);
484 if (IS_ERR(ima_policy))
489 securityfs_remove(violations);
490 securityfs_remove(runtime_measurements_count);
491 securityfs_remove(ascii_runtime_measurements);
492 securityfs_remove(binary_runtime_measurements);
493 securityfs_remove(ima_dir);
494 securityfs_remove(ima_policy);