1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
6 * Kylene Hall <kjhall@us.ibm.com>
7 * Reiner Sailer <sailer@us.ibm.com>
8 * Mimi Zohar <zohar@us.ibm.com>
11 * implemenents security file system for reporting
12 * current measurement list and IMA statistics
15 #include <linux/fcntl.h>
16 #include <linux/slab.h>
17 #include <linux/init.h>
18 #include <linux/seq_file.h>
19 #include <linux/rculist.h>
20 #include <linux/rcupdate.h>
21 #include <linux/parser.h>
22 #include <linux/vmalloc.h>
26 static DEFINE_MUTEX(ima_write_mutex
);
28 bool ima_canonical_fmt
;
29 static int __init
default_canonical_fmt_setup(char *str
)
32 ima_canonical_fmt
= true;
36 __setup("ima_canonical_fmt", default_canonical_fmt_setup
);
38 static int valid_policy
= 1;
40 static ssize_t
ima_show_htable_value(char __user
*buf
, size_t count
,
41 loff_t
*ppos
, atomic_long_t
*val
)
43 char tmpbuf
[32]; /* greater than largest 'long' string value */
46 len
= scnprintf(tmpbuf
, sizeof(tmpbuf
), "%li\n", atomic_long_read(val
));
47 return simple_read_from_buffer(buf
, count
, ppos
, tmpbuf
, len
);
50 static ssize_t
ima_show_htable_violations(struct file
*filp
,
52 size_t count
, loff_t
*ppos
)
54 return ima_show_htable_value(buf
, count
, ppos
, &ima_htable
.violations
);
57 static const struct file_operations ima_htable_violations_ops
= {
58 .read
= ima_show_htable_violations
,
59 .llseek
= generic_file_llseek
,
62 static ssize_t
ima_show_measurements_count(struct file
*filp
,
64 size_t count
, loff_t
*ppos
)
66 return ima_show_htable_value(buf
, count
, ppos
, &ima_htable
.len
);
70 static const struct file_operations ima_measurements_count_ops
= {
71 .read
= ima_show_measurements_count
,
72 .llseek
= generic_file_llseek
,
75 /* returns pointer to hlist_node */
76 static void *ima_measurements_start(struct seq_file
*m
, loff_t
*pos
)
79 struct ima_queue_entry
*qe
;
81 /* we need a lock since pos could point beyond last element */
83 list_for_each_entry_rcu(qe
, &ima_measurements
, later
) {
93 static void *ima_measurements_next(struct seq_file
*m
, void *v
, loff_t
*pos
)
95 struct ima_queue_entry
*qe
= v
;
97 /* lock protects when reading beyond last element
98 * against concurrent list-extension
101 qe
= list_entry_rcu(qe
->later
.next
, struct ima_queue_entry
, later
);
105 return (&qe
->later
== &ima_measurements
) ? NULL
: qe
;
108 static void ima_measurements_stop(struct seq_file
*m
, void *v
)
112 void ima_putc(struct seq_file
*m
, void *data
, int datalen
)
115 seq_putc(m
, *(char *)data
++);
120 * char[20]=template digest
121 * 32bit-le=template name size
122 * char[n]=template name
124 * eventdata[n]=template specific data
126 int ima_measurements_show(struct seq_file
*m
, void *v
)
128 /* the list never shrinks, so we don't need a lock here */
129 struct ima_queue_entry
*qe
= v
;
130 struct ima_template_entry
*e
;
132 u32 pcr
, namelen
, template_data_len
; /* temporary fields */
133 bool is_ima_template
= false;
141 template_name
= (e
->template_desc
->name
[0] != '\0') ?
142 e
->template_desc
->name
: e
->template_desc
->fmt
;
146 * PCR used defaults to the same (config option) in
147 * little-endian format, unless set in policy
149 pcr
= !ima_canonical_fmt
? e
->pcr
: cpu_to_le32(e
->pcr
);
150 ima_putc(m
, &pcr
, sizeof(e
->pcr
));
152 /* 2nd: template digest */
153 ima_putc(m
, e
->digest
, TPM_DIGEST_SIZE
);
155 /* 3rd: template name size */
156 namelen
= !ima_canonical_fmt
? strlen(template_name
) :
157 cpu_to_le32(strlen(template_name
));
158 ima_putc(m
, &namelen
, sizeof(namelen
));
160 /* 4th: template name */
161 ima_putc(m
, template_name
, strlen(template_name
));
163 /* 5th: template length (except for 'ima' template) */
164 if (strcmp(template_name
, IMA_TEMPLATE_IMA_NAME
) == 0)
165 is_ima_template
= true;
167 if (!is_ima_template
) {
168 template_data_len
= !ima_canonical_fmt
? e
->template_data_len
:
169 cpu_to_le32(e
->template_data_len
);
170 ima_putc(m
, &template_data_len
, sizeof(e
->template_data_len
));
173 /* 6th: template specific data */
174 for (i
= 0; i
< e
->template_desc
->num_fields
; i
++) {
175 enum ima_show_type show
= IMA_SHOW_BINARY
;
176 const struct ima_template_field
*field
=
177 e
->template_desc
->fields
[i
];
179 if (is_ima_template
&& strcmp(field
->field_id
, "d") == 0)
180 show
= IMA_SHOW_BINARY_NO_FIELD_LEN
;
181 if (is_ima_template
&& strcmp(field
->field_id
, "n") == 0)
182 show
= IMA_SHOW_BINARY_OLD_STRING_FMT
;
183 field
->field_show(m
, show
, &e
->template_data
[i
]);
188 static const struct seq_operations ima_measurments_seqops
= {
189 .start
= ima_measurements_start
,
190 .next
= ima_measurements_next
,
191 .stop
= ima_measurements_stop
,
192 .show
= ima_measurements_show
195 static int ima_measurements_open(struct inode
*inode
, struct file
*file
)
197 return seq_open(file
, &ima_measurments_seqops
);
200 static const struct file_operations ima_measurements_ops
= {
201 .open
= ima_measurements_open
,
204 .release
= seq_release
,
207 void ima_print_digest(struct seq_file
*m
, u8
*digest
, u32 size
)
211 for (i
= 0; i
< size
; i
++)
212 seq_printf(m
, "%02x", *(digest
+ i
));
216 static int ima_ascii_measurements_show(struct seq_file
*m
, void *v
)
218 /* the list never shrinks, so we don't need a lock here */
219 struct ima_queue_entry
*qe
= v
;
220 struct ima_template_entry
*e
;
229 template_name
= (e
->template_desc
->name
[0] != '\0') ?
230 e
->template_desc
->name
: e
->template_desc
->fmt
;
232 /* 1st: PCR used (config option) */
233 seq_printf(m
, "%2d ", e
->pcr
);
235 /* 2nd: SHA1 template hash */
236 ima_print_digest(m
, e
->digest
, TPM_DIGEST_SIZE
);
238 /* 3th: template name */
239 seq_printf(m
, " %s", template_name
);
241 /* 4th: template specific data */
242 for (i
= 0; i
< e
->template_desc
->num_fields
; i
++) {
244 if (e
->template_data
[i
].len
== 0)
247 e
->template_desc
->fields
[i
]->field_show(m
, IMA_SHOW_ASCII
,
248 &e
->template_data
[i
]);
254 static const struct seq_operations ima_ascii_measurements_seqops
= {
255 .start
= ima_measurements_start
,
256 .next
= ima_measurements_next
,
257 .stop
= ima_measurements_stop
,
258 .show
= ima_ascii_measurements_show
261 static int ima_ascii_measurements_open(struct inode
*inode
, struct file
*file
)
263 return seq_open(file
, &ima_ascii_measurements_seqops
);
266 static const struct file_operations ima_ascii_measurements_ops
= {
267 .open
= ima_ascii_measurements_open
,
270 .release
= seq_release
,
273 static ssize_t
ima_read_policy(char *path
)
278 int rc
, pathlen
= strlen(path
);
284 strsep(&datap
, "\n");
286 rc
= kernel_read_file_from_path(path
, &data
, &size
, 0, READING_POLICY
);
288 pr_err("Unable to open file: %s (%d)", path
, rc
);
293 while (size
> 0 && (p
= strsep(&datap
, "\n"))) {
294 pr_debug("rule: %s\n", p
);
295 rc
= ima_parse_add_rule(p
);
310 static ssize_t
ima_write_policy(struct file
*file
, const char __user
*buf
,
311 size_t datalen
, loff_t
*ppos
)
316 if (datalen
>= PAGE_SIZE
)
317 datalen
= PAGE_SIZE
- 1;
319 /* No partial writes. */
324 data
= memdup_user_nul(buf
, datalen
);
326 result
= PTR_ERR(data
);
330 result
= mutex_lock_interruptible(&ima_write_mutex
);
334 if (data
[0] == '/') {
335 result
= ima_read_policy(data
);
336 } else if (ima_appraise
& IMA_APPRAISE_POLICY
) {
337 pr_err("signed policy file (specified as an absolute pathname) required\n");
338 integrity_audit_msg(AUDIT_INTEGRITY_STATUS
, NULL
, NULL
,
339 "policy_update", "signed policy required",
343 result
= ima_parse_add_rule(data
);
345 mutex_unlock(&ima_write_mutex
);
355 static struct dentry
*ima_dir
;
356 static struct dentry
*ima_symlink
;
357 static struct dentry
*binary_runtime_measurements
;
358 static struct dentry
*ascii_runtime_measurements
;
359 static struct dentry
*runtime_measurements_count
;
360 static struct dentry
*violations
;
361 static struct dentry
*ima_policy
;
367 static unsigned long ima_fs_flags
;
369 #ifdef CONFIG_IMA_READ_POLICY
370 static const struct seq_operations ima_policy_seqops
= {
371 .start
= ima_policy_start
,
372 .next
= ima_policy_next
,
373 .stop
= ima_policy_stop
,
374 .show
= ima_policy_show
,
379 * ima_open_policy: sequentialize access to the policy file
381 static int ima_open_policy(struct inode
*inode
, struct file
*filp
)
383 if (!(filp
->f_flags
& O_WRONLY
)) {
384 #ifndef CONFIG_IMA_READ_POLICY
387 if ((filp
->f_flags
& O_ACCMODE
) != O_RDONLY
)
389 if (!capable(CAP_SYS_ADMIN
))
391 return seq_open(filp
, &ima_policy_seqops
);
394 if (test_and_set_bit(IMA_FS_BUSY
, &ima_fs_flags
))
400 * ima_release_policy - start using the new measure policy rules.
402 * Initially, ima_measure points to the default policy rules, now
403 * point to the new policy rules, and remove the securityfs policy file,
404 * assuming a valid policy.
406 static int ima_release_policy(struct inode
*inode
, struct file
*file
)
408 const char *cause
= valid_policy
? "completed" : "failed";
410 if ((file
->f_flags
& O_ACCMODE
) == O_RDONLY
)
411 return seq_release(inode
, file
);
413 if (valid_policy
&& ima_check_policy() < 0) {
418 pr_info("policy update %s\n", cause
);
419 integrity_audit_msg(AUDIT_INTEGRITY_STATUS
, NULL
, NULL
,
420 "policy_update", cause
, !valid_policy
, 0);
425 clear_bit(IMA_FS_BUSY
, &ima_fs_flags
);
430 #if !defined(CONFIG_IMA_WRITE_POLICY) && !defined(CONFIG_IMA_READ_POLICY)
431 securityfs_remove(ima_policy
);
433 #elif defined(CONFIG_IMA_WRITE_POLICY)
434 clear_bit(IMA_FS_BUSY
, &ima_fs_flags
);
435 #elif defined(CONFIG_IMA_READ_POLICY)
436 inode
->i_mode
&= ~S_IWUSR
;
441 static const struct file_operations ima_measure_policy_ops
= {
442 .open
= ima_open_policy
,
443 .write
= ima_write_policy
,
445 .release
= ima_release_policy
,
446 .llseek
= generic_file_llseek
,
449 int __init
ima_fs_init(void)
451 ima_dir
= securityfs_create_dir("ima", integrity_dir
);
455 ima_symlink
= securityfs_create_symlink("ima", NULL
, "integrity/ima",
457 if (IS_ERR(ima_symlink
))
460 binary_runtime_measurements
=
461 securityfs_create_file("binary_runtime_measurements",
462 S_IRUSR
| S_IRGRP
, ima_dir
, NULL
,
463 &ima_measurements_ops
);
464 if (IS_ERR(binary_runtime_measurements
))
467 ascii_runtime_measurements
=
468 securityfs_create_file("ascii_runtime_measurements",
469 S_IRUSR
| S_IRGRP
, ima_dir
, NULL
,
470 &ima_ascii_measurements_ops
);
471 if (IS_ERR(ascii_runtime_measurements
))
474 runtime_measurements_count
=
475 securityfs_create_file("runtime_measurements_count",
476 S_IRUSR
| S_IRGRP
, ima_dir
, NULL
,
477 &ima_measurements_count_ops
);
478 if (IS_ERR(runtime_measurements_count
))
482 securityfs_create_file("violations", S_IRUSR
| S_IRGRP
,
483 ima_dir
, NULL
, &ima_htable_violations_ops
);
484 if (IS_ERR(violations
))
487 ima_policy
= securityfs_create_file("policy", POLICY_FILE_FLAGS
,
489 &ima_measure_policy_ops
);
490 if (IS_ERR(ima_policy
))
495 securityfs_remove(violations
);
496 securityfs_remove(runtime_measurements_count
);
497 securityfs_remove(ascii_runtime_measurements
);
498 securityfs_remove(binary_runtime_measurements
);
499 securityfs_remove(ima_symlink
);
500 securityfs_remove(ima_dir
);
501 securityfs_remove(ima_policy
);