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
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 #include <linux/fcntl.h>
22 #include <linux/slab.h>
23 #include <linux/module.h>
24 #include <linux/seq_file.h>
25 #include <linux/rculist.h>
26 #include <linux/rcupdate.h>
27 #include <linux/parser.h>
28 #include <linux/vmalloc.h>
32 static DEFINE_MUTEX(ima_write_mutex);
34 bool ima_canonical_fmt;
35 static int __init default_canonical_fmt_setup(char *str)
38 ima_canonical_fmt = true;
42 __setup("ima_canonical_fmt", default_canonical_fmt_setup);
44 static int valid_policy = 1;
46 static ssize_t ima_show_htable_value(char __user *buf, size_t count,
47 loff_t *ppos, atomic_long_t *val)
49 char tmpbuf[32]; /* greater than largest 'long' string value */
52 len = scnprintf(tmpbuf, sizeof(tmpbuf), "%li\n", atomic_long_read(val));
53 return simple_read_from_buffer(buf, count, ppos, tmpbuf, len);
56 static ssize_t ima_show_htable_violations(struct file *filp,
58 size_t count, loff_t *ppos)
60 return ima_show_htable_value(buf, count, ppos, &ima_htable.violations);
63 static const struct file_operations ima_htable_violations_ops = {
64 .read = ima_show_htable_violations,
65 .llseek = generic_file_llseek,
68 static ssize_t ima_show_measurements_count(struct file *filp,
70 size_t count, loff_t *ppos)
72 return ima_show_htable_value(buf, count, ppos, &ima_htable.len);
76 static const struct file_operations ima_measurements_count_ops = {
77 .read = ima_show_measurements_count,
78 .llseek = generic_file_llseek,
81 /* returns pointer to hlist_node */
82 static void *ima_measurements_start(struct seq_file *m, loff_t *pos)
85 struct ima_queue_entry *qe;
87 /* we need a lock since pos could point beyond last element */
89 list_for_each_entry_rcu(qe, &ima_measurements, later) {
99 static void *ima_measurements_next(struct seq_file *m, void *v, loff_t *pos)
101 struct ima_queue_entry *qe = v;
103 /* lock protects when reading beyond last element
104 * against concurrent list-extension
107 qe = list_entry_rcu(qe->later.next, struct ima_queue_entry, later);
111 return (&qe->later == &ima_measurements) ? NULL : qe;
114 static void ima_measurements_stop(struct seq_file *m, void *v)
118 void ima_putc(struct seq_file *m, void *data, int datalen)
121 seq_putc(m, *(char *)data++);
126 * char[20]=template digest
127 * 32bit-le=template name size
128 * char[n]=template name
130 * eventdata[n]=template specific data
132 int ima_measurements_show(struct seq_file *m, void *v)
134 /* the list never shrinks, so we don't need a lock here */
135 struct ima_queue_entry *qe = v;
136 struct ima_template_entry *e;
138 u32 pcr, namelen, template_data_len; /* temporary fields */
139 bool is_ima_template = false;
147 template_name = (e->template_desc->name[0] != '\0') ?
148 e->template_desc->name : e->template_desc->fmt;
152 * PCR used defaults to the same (config option) in
153 * little-endian format, unless set in policy
155 pcr = !ima_canonical_fmt ? e->pcr : cpu_to_le32(e->pcr);
156 ima_putc(m, &pcr, sizeof(e->pcr));
158 /* 2nd: template digest */
159 ima_putc(m, e->digest, TPM_DIGEST_SIZE);
161 /* 3rd: template name size */
162 namelen = !ima_canonical_fmt ? strlen(template_name) :
163 cpu_to_le32(strlen(template_name));
164 ima_putc(m, &namelen, sizeof(namelen));
166 /* 4th: template name */
167 ima_putc(m, template_name, strlen(template_name));
169 /* 5th: template length (except for 'ima' template) */
170 if (strcmp(template_name, IMA_TEMPLATE_IMA_NAME) == 0)
171 is_ima_template = true;
173 if (!is_ima_template) {
174 template_data_len = !ima_canonical_fmt ? e->template_data_len :
175 cpu_to_le32(e->template_data_len);
176 ima_putc(m, &template_data_len, sizeof(e->template_data_len));
179 /* 6th: template specific data */
180 for (i = 0; i < e->template_desc->num_fields; i++) {
181 enum ima_show_type show = IMA_SHOW_BINARY;
182 struct ima_template_field *field = e->template_desc->fields[i];
184 if (is_ima_template && strcmp(field->field_id, "d") == 0)
185 show = IMA_SHOW_BINARY_NO_FIELD_LEN;
186 if (is_ima_template && strcmp(field->field_id, "n") == 0)
187 show = IMA_SHOW_BINARY_OLD_STRING_FMT;
188 field->field_show(m, show, &e->template_data[i]);
193 static const struct seq_operations ima_measurments_seqops = {
194 .start = ima_measurements_start,
195 .next = ima_measurements_next,
196 .stop = ima_measurements_stop,
197 .show = ima_measurements_show
200 static int ima_measurements_open(struct inode *inode, struct file *file)
202 return seq_open(file, &ima_measurments_seqops);
205 static const struct file_operations ima_measurements_ops = {
206 .open = ima_measurements_open,
209 .release = seq_release,
212 void ima_print_digest(struct seq_file *m, u8 *digest, u32 size)
216 for (i = 0; i < size; i++)
217 seq_printf(m, "%02x", *(digest + i));
221 static int ima_ascii_measurements_show(struct seq_file *m, void *v)
223 /* the list never shrinks, so we don't need a lock here */
224 struct ima_queue_entry *qe = v;
225 struct ima_template_entry *e;
234 template_name = (e->template_desc->name[0] != '\0') ?
235 e->template_desc->name : e->template_desc->fmt;
237 /* 1st: PCR used (config option) */
238 seq_printf(m, "%2d ", e->pcr);
240 /* 2nd: SHA1 template hash */
241 ima_print_digest(m, e->digest, TPM_DIGEST_SIZE);
243 /* 3th: template name */
244 seq_printf(m, " %s", template_name);
246 /* 4th: template specific data */
247 for (i = 0; i < e->template_desc->num_fields; i++) {
249 if (e->template_data[i].len == 0)
252 e->template_desc->fields[i]->field_show(m, IMA_SHOW_ASCII,
253 &e->template_data[i]);
259 static const struct seq_operations ima_ascii_measurements_seqops = {
260 .start = ima_measurements_start,
261 .next = ima_measurements_next,
262 .stop = ima_measurements_stop,
263 .show = ima_ascii_measurements_show
266 static int ima_ascii_measurements_open(struct inode *inode, struct file *file)
268 return seq_open(file, &ima_ascii_measurements_seqops);
271 static const struct file_operations ima_ascii_measurements_ops = {
272 .open = ima_ascii_measurements_open,
275 .release = seq_release,
278 static ssize_t ima_read_policy(char *path)
283 int rc, pathlen = strlen(path);
289 strsep(&datap, "\n");
291 rc = kernel_read_file_from_path(path, &data, &size, 0, READING_POLICY);
293 pr_err("Unable to open file: %s (%d)", path, rc);
298 while (size > 0 && (p = strsep(&datap, "\n"))) {
299 pr_debug("rule: %s\n", p);
300 rc = ima_parse_add_rule(p);
315 static ssize_t ima_write_policy(struct file *file, const char __user *buf,
316 size_t datalen, loff_t *ppos)
321 if (datalen >= PAGE_SIZE)
322 datalen = PAGE_SIZE - 1;
324 /* No partial writes. */
329 data = memdup_user_nul(buf, datalen);
331 result = PTR_ERR(data);
335 result = mutex_lock_interruptible(&ima_write_mutex);
339 if (data[0] == '/') {
340 result = ima_read_policy(data);
341 } else if (ima_appraise & IMA_APPRAISE_POLICY) {
342 pr_err("signed policy file (specified as an absolute pathname) required\n");
343 integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
344 "policy_update", "signed policy required",
348 result = ima_parse_add_rule(data);
350 mutex_unlock(&ima_write_mutex);
360 static struct dentry *ima_dir;
361 static struct dentry *ima_symlink;
362 static struct dentry *binary_runtime_measurements;
363 static struct dentry *ascii_runtime_measurements;
364 static struct dentry *runtime_measurements_count;
365 static struct dentry *violations;
366 static struct dentry *ima_policy;
372 static unsigned long ima_fs_flags;
374 #ifdef CONFIG_IMA_READ_POLICY
375 static const struct seq_operations ima_policy_seqops = {
376 .start = ima_policy_start,
377 .next = ima_policy_next,
378 .stop = ima_policy_stop,
379 .show = ima_policy_show,
384 * ima_open_policy: sequentialize access to the policy file
386 static int ima_open_policy(struct inode *inode, struct file *filp)
388 if (!(filp->f_flags & O_WRONLY)) {
389 #ifndef CONFIG_IMA_READ_POLICY
392 if ((filp->f_flags & O_ACCMODE) != O_RDONLY)
394 if (!capable(CAP_SYS_ADMIN))
396 return seq_open(filp, &ima_policy_seqops);
399 if (test_and_set_bit(IMA_FS_BUSY, &ima_fs_flags))
405 * ima_release_policy - start using the new measure policy rules.
407 * Initially, ima_measure points to the default policy rules, now
408 * point to the new policy rules, and remove the securityfs policy file,
409 * assuming a valid policy.
411 static int ima_release_policy(struct inode *inode, struct file *file)
413 const char *cause = valid_policy ? "completed" : "failed";
415 if ((file->f_flags & O_ACCMODE) == O_RDONLY)
416 return seq_release(inode, file);
418 if (valid_policy && ima_check_policy() < 0) {
423 pr_info("policy update %s\n", cause);
424 integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
425 "policy_update", cause, !valid_policy, 0);
430 clear_bit(IMA_FS_BUSY, &ima_fs_flags);
435 #if !defined(CONFIG_IMA_WRITE_POLICY) && !defined(CONFIG_IMA_READ_POLICY)
436 securityfs_remove(ima_policy);
438 #elif defined(CONFIG_IMA_WRITE_POLICY)
439 clear_bit(IMA_FS_BUSY, &ima_fs_flags);
440 #elif defined(CONFIG_IMA_READ_POLICY)
441 inode->i_mode &= ~S_IWUSR;
446 static const struct file_operations ima_measure_policy_ops = {
447 .open = ima_open_policy,
448 .write = ima_write_policy,
450 .release = ima_release_policy,
451 .llseek = generic_file_llseek,
454 int __init ima_fs_init(void)
456 ima_dir = securityfs_create_dir("ima", integrity_dir);
460 ima_symlink = securityfs_create_symlink("ima", NULL, "integrity/ima",
462 if (IS_ERR(ima_symlink))
465 binary_runtime_measurements =
466 securityfs_create_file("binary_runtime_measurements",
467 S_IRUSR | S_IRGRP, ima_dir, NULL,
468 &ima_measurements_ops);
469 if (IS_ERR(binary_runtime_measurements))
472 ascii_runtime_measurements =
473 securityfs_create_file("ascii_runtime_measurements",
474 S_IRUSR | S_IRGRP, ima_dir, NULL,
475 &ima_ascii_measurements_ops);
476 if (IS_ERR(ascii_runtime_measurements))
479 runtime_measurements_count =
480 securityfs_create_file("runtime_measurements_count",
481 S_IRUSR | S_IRGRP, ima_dir, NULL,
482 &ima_measurements_count_ops);
483 if (IS_ERR(runtime_measurements_count))
487 securityfs_create_file("violations", S_IRUSR | S_IRGRP,
488 ima_dir, NULL, &ima_htable_violations_ops);
489 if (IS_ERR(violations))
492 ima_policy = securityfs_create_file("policy", POLICY_FILE_FLAGS,
494 &ima_measure_policy_ops);
495 if (IS_ERR(ima_policy))
500 securityfs_remove(violations);
501 securityfs_remove(runtime_measurements_count);
502 securityfs_remove(ascii_runtime_measurements);
503 securityfs_remove(binary_runtime_measurements);
504 securityfs_remove(ima_symlink);
505 securityfs_remove(ima_dir);
506 securityfs_remove(ima_policy);