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 static int valid_policy
= 1;
33 static ssize_t
ima_show_htable_value(char __user
*buf
, size_t count
,
34 loff_t
*ppos
, atomic_long_t
*val
)
36 char tmpbuf
[TMPBUFLEN
];
39 len
= scnprintf(tmpbuf
, TMPBUFLEN
, "%li\n", atomic_long_read(val
));
40 return simple_read_from_buffer(buf
, count
, ppos
, tmpbuf
, len
);
43 static ssize_t
ima_show_htable_violations(struct file
*filp
,
45 size_t count
, loff_t
*ppos
)
47 return ima_show_htable_value(buf
, count
, ppos
, &ima_htable
.violations
);
50 static const struct file_operations ima_htable_violations_ops
= {
51 .read
= ima_show_htable_violations
,
52 .llseek
= generic_file_llseek
,
55 static ssize_t
ima_show_measurements_count(struct file
*filp
,
57 size_t count
, loff_t
*ppos
)
59 return ima_show_htable_value(buf
, count
, ppos
, &ima_htable
.len
);
63 static const struct file_operations ima_measurements_count_ops
= {
64 .read
= ima_show_measurements_count
,
65 .llseek
= generic_file_llseek
,
68 /* returns pointer to hlist_node */
69 static void *ima_measurements_start(struct seq_file
*m
, loff_t
*pos
)
72 struct ima_queue_entry
*qe
;
74 /* we need a lock since pos could point beyond last element */
76 list_for_each_entry_rcu(qe
, &ima_measurements
, later
) {
86 static void *ima_measurements_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
88 struct ima_queue_entry
*qe
= v
;
90 /* lock protects when reading beyond last element
91 * against concurrent list-extension
94 qe
= list_entry_rcu(qe
->later
.next
, struct ima_queue_entry
, later
);
98 return (&qe
->later
== &ima_measurements
) ? NULL
: qe
;
101 static void ima_measurements_stop(struct seq_file
*m
, void *v
)
105 void ima_putc(struct seq_file
*m
, void *data
, int datalen
)
108 seq_putc(m
, *(char *)data
++);
113 * char[20]=template digest
114 * 32bit-le=template name size
115 * char[n]=template name
117 * eventdata[n]=template specific data
119 static int ima_measurements_show(struct seq_file
*m
, void *v
)
121 /* the list never shrinks, so we don't need a lock here */
122 struct ima_queue_entry
*qe
= v
;
123 struct ima_template_entry
*e
;
126 u32 pcr
= CONFIG_IMA_MEASURE_PCR_IDX
;
127 bool is_ima_template
= false;
135 template_name
= (e
->template_desc
->name
[0] != '\0') ?
136 e
->template_desc
->name
: e
->template_desc
->fmt
;
140 * PCR used is always the same (config option) in
141 * little-endian format
143 ima_putc(m
, &pcr
, sizeof(pcr
));
145 /* 2nd: template digest */
146 ima_putc(m
, e
->digest
, TPM_DIGEST_SIZE
);
148 /* 3rd: template name size */
149 namelen
= strlen(template_name
);
150 ima_putc(m
, &namelen
, sizeof(namelen
));
152 /* 4th: template name */
153 ima_putc(m
, template_name
, namelen
);
155 /* 5th: template length (except for 'ima' template) */
156 if (strcmp(template_name
, IMA_TEMPLATE_IMA_NAME
) == 0)
157 is_ima_template
= true;
159 if (!is_ima_template
)
160 ima_putc(m
, &e
->template_data_len
,
161 sizeof(e
->template_data_len
));
163 /* 6th: template specific data */
164 for (i
= 0; i
< e
->template_desc
->num_fields
; i
++) {
165 enum ima_show_type show
= IMA_SHOW_BINARY
;
166 struct ima_template_field
*field
= e
->template_desc
->fields
[i
];
168 if (is_ima_template
&& strcmp(field
->field_id
, "d") == 0)
169 show
= IMA_SHOW_BINARY_NO_FIELD_LEN
;
170 if (is_ima_template
&& strcmp(field
->field_id
, "n") == 0)
171 show
= IMA_SHOW_BINARY_OLD_STRING_FMT
;
172 field
->field_show(m
, show
, &e
->template_data
[i
]);
177 static const struct seq_operations ima_measurments_seqops
= {
178 .start
= ima_measurements_start
,
179 .next
= ima_measurements_next
,
180 .stop
= ima_measurements_stop
,
181 .show
= ima_measurements_show
184 static int ima_measurements_open(struct inode
*inode
, struct file
*file
)
186 return seq_open(file
, &ima_measurments_seqops
);
189 static const struct file_operations ima_measurements_ops
= {
190 .open
= ima_measurements_open
,
193 .release
= seq_release
,
196 void ima_print_digest(struct seq_file
*m
, u8
*digest
, u32 size
)
200 for (i
= 0; i
< size
; i
++)
201 seq_printf(m
, "%02x", *(digest
+ i
));
205 static int ima_ascii_measurements_show(struct seq_file
*m
, void *v
)
207 /* the list never shrinks, so we don't need a lock here */
208 struct ima_queue_entry
*qe
= v
;
209 struct ima_template_entry
*e
;
218 template_name
= (e
->template_desc
->name
[0] != '\0') ?
219 e
->template_desc
->name
: e
->template_desc
->fmt
;
221 /* 1st: PCR used (config option) */
222 seq_printf(m
, "%2d ", CONFIG_IMA_MEASURE_PCR_IDX
);
224 /* 2nd: SHA1 template hash */
225 ima_print_digest(m
, e
->digest
, TPM_DIGEST_SIZE
);
227 /* 3th: template name */
228 seq_printf(m
, " %s", template_name
);
230 /* 4th: template specific data */
231 for (i
= 0; i
< e
->template_desc
->num_fields
; i
++) {
233 if (e
->template_data
[i
].len
== 0)
236 e
->template_desc
->fields
[i
]->field_show(m
, IMA_SHOW_ASCII
,
237 &e
->template_data
[i
]);
243 static const struct seq_operations ima_ascii_measurements_seqops
= {
244 .start
= ima_measurements_start
,
245 .next
= ima_measurements_next
,
246 .stop
= ima_measurements_stop
,
247 .show
= ima_ascii_measurements_show
250 static int ima_ascii_measurements_open(struct inode
*inode
, struct file
*file
)
252 return seq_open(file
, &ima_ascii_measurements_seqops
);
255 static const struct file_operations ima_ascii_measurements_ops
= {
256 .open
= ima_ascii_measurements_open
,
259 .release
= seq_release
,
262 static ssize_t
ima_read_policy(char *path
)
267 int rc
, pathlen
= strlen(path
);
273 strsep(&datap
, "\n");
275 rc
= kernel_read_file_from_path(path
, &data
, &size
, 0, READING_POLICY
);
277 pr_err("Unable to open file: %s (%d)", path
, rc
);
282 while (size
> 0 && (p
= strsep(&datap
, "\n"))) {
283 pr_debug("rule: %s\n", p
);
284 rc
= ima_parse_add_rule(p
);
299 static ssize_t
ima_write_policy(struct file
*file
, const char __user
*buf
,
300 size_t datalen
, loff_t
*ppos
)
305 if (datalen
>= PAGE_SIZE
)
306 datalen
= PAGE_SIZE
- 1;
308 /* No partial writes. */
314 data
= kmalloc(datalen
+ 1, GFP_KERNEL
);
318 *(data
+ datalen
) = '\0';
321 if (copy_from_user(data
, buf
, datalen
))
324 result
= mutex_lock_interruptible(&ima_write_mutex
);
328 if (data
[0] == '/') {
329 result
= ima_read_policy(data
);
330 } else if (ima_appraise
& IMA_APPRAISE_POLICY
) {
331 pr_err("IMA: signed policy file (specified as an absolute pathname) required\n");
332 integrity_audit_msg(AUDIT_INTEGRITY_STATUS
, NULL
, NULL
,
333 "policy_update", "signed policy required",
335 if (ima_appraise
& IMA_APPRAISE_ENFORCE
)
338 result
= ima_parse_add_rule(data
);
340 mutex_unlock(&ima_write_mutex
);
350 static struct dentry
*ima_dir
;
351 static struct dentry
*binary_runtime_measurements
;
352 static struct dentry
*ascii_runtime_measurements
;
353 static struct dentry
*runtime_measurements_count
;
354 static struct dentry
*violations
;
355 static struct dentry
*ima_policy
;
361 static unsigned long ima_fs_flags
;
363 #ifdef CONFIG_IMA_READ_POLICY
364 static const struct seq_operations ima_policy_seqops
= {
365 .start
= ima_policy_start
,
366 .next
= ima_policy_next
,
367 .stop
= ima_policy_stop
,
368 .show
= ima_policy_show
,
373 * ima_open_policy: sequentialize access to the policy file
375 static int ima_open_policy(struct inode
*inode
, struct file
*filp
)
377 if (!(filp
->f_flags
& O_WRONLY
)) {
378 #ifndef CONFIG_IMA_READ_POLICY
381 if ((filp
->f_flags
& O_ACCMODE
) != O_RDONLY
)
383 if (!capable(CAP_SYS_ADMIN
))
385 return seq_open(filp
, &ima_policy_seqops
);
388 if (test_and_set_bit(IMA_FS_BUSY
, &ima_fs_flags
))
394 * ima_release_policy - start using the new measure policy rules.
396 * Initially, ima_measure points to the default policy rules, now
397 * point to the new policy rules, and remove the securityfs policy file,
398 * assuming a valid policy.
400 static int ima_release_policy(struct inode
*inode
, struct file
*file
)
402 const char *cause
= valid_policy
? "completed" : "failed";
404 if ((file
->f_flags
& O_ACCMODE
) == O_RDONLY
)
407 if (valid_policy
&& ima_check_policy() < 0) {
412 pr_info("IMA: policy update %s\n", cause
);
413 integrity_audit_msg(AUDIT_INTEGRITY_STATUS
, NULL
, NULL
,
414 "policy_update", cause
, !valid_policy
, 0);
419 clear_bit(IMA_FS_BUSY
, &ima_fs_flags
);
424 #ifndef CONFIG_IMA_WRITE_POLICY
425 securityfs_remove(ima_policy
);
428 clear_bit(IMA_FS_BUSY
, &ima_fs_flags
);
433 static const struct file_operations ima_measure_policy_ops
= {
434 .open
= ima_open_policy
,
435 .write
= ima_write_policy
,
437 .release
= ima_release_policy
,
438 .llseek
= generic_file_llseek
,
441 int __init
ima_fs_init(void)
443 ima_dir
= securityfs_create_dir("ima", NULL
);
447 binary_runtime_measurements
=
448 securityfs_create_file("binary_runtime_measurements",
449 S_IRUSR
| S_IRGRP
, ima_dir
, NULL
,
450 &ima_measurements_ops
);
451 if (IS_ERR(binary_runtime_measurements
))
454 ascii_runtime_measurements
=
455 securityfs_create_file("ascii_runtime_measurements",
456 S_IRUSR
| S_IRGRP
, ima_dir
, NULL
,
457 &ima_ascii_measurements_ops
);
458 if (IS_ERR(ascii_runtime_measurements
))
461 runtime_measurements_count
=
462 securityfs_create_file("runtime_measurements_count",
463 S_IRUSR
| S_IRGRP
, ima_dir
, NULL
,
464 &ima_measurements_count_ops
);
465 if (IS_ERR(runtime_measurements_count
))
469 securityfs_create_file("violations", S_IRUSR
| S_IRGRP
,
470 ima_dir
, NULL
, &ima_htable_violations_ops
);
471 if (IS_ERR(violations
))
474 ima_policy
= securityfs_create_file("policy", POLICY_FILE_FLAGS
,
476 &ima_measure_policy_ops
);
477 if (IS_ERR(ima_policy
))
482 securityfs_remove(violations
);
483 securityfs_remove(runtime_measurements_count
);
484 securityfs_remove(ascii_runtime_measurements
);
485 securityfs_remove(binary_runtime_measurements
);
486 securityfs_remove(ima_dir
);
487 securityfs_remove(ima_policy
);