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12#include <linux/rculist.h>
13#include "ima.h"
14#include "ima_template_lib.h"
15
16enum header_fields { HDR_PCR, HDR_DIGEST, HDR_TEMPLATE_NAME,
17 HDR_TEMPLATE_DATA, HDR__LAST };
18
19static struct ima_template_desc builtin_templates[] = {
20 {.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT},
21 {.name = "ima-ng", .fmt = "d-ng|n-ng"},
22 {.name = "ima-sig", .fmt = "d-ng|n-ng|sig"},
23 {.name = "ima-buf", .fmt = "d-ng|n-ng|buf"},
24 {.name = "ima-modsig", .fmt = "d-ng|n-ng|sig|d-modsig|modsig"},
25 {.name = "evm-sig",
26 .fmt = "d-ng|n-ng|evmsig|xattrnames|xattrlengths|xattrvalues|iuid|igid|imode"},
27 {.name = "", .fmt = ""},
28};
29
30static LIST_HEAD(defined_templates);
31static DEFINE_SPINLOCK(template_list);
32static int template_setup_done;
33
34static const struct ima_template_field supported_fields[] = {
35 {.field_id = "d", .field_init = ima_eventdigest_init,
36 .field_show = ima_show_template_digest},
37 {.field_id = "n", .field_init = ima_eventname_init,
38 .field_show = ima_show_template_string},
39 {.field_id = "d-ng", .field_init = ima_eventdigest_ng_init,
40 .field_show = ima_show_template_digest_ng},
41 {.field_id = "n-ng", .field_init = ima_eventname_ng_init,
42 .field_show = ima_show_template_string},
43 {.field_id = "sig", .field_init = ima_eventsig_init,
44 .field_show = ima_show_template_sig},
45 {.field_id = "buf", .field_init = ima_eventbuf_init,
46 .field_show = ima_show_template_buf},
47 {.field_id = "d-modsig", .field_init = ima_eventdigest_modsig_init,
48 .field_show = ima_show_template_digest_ng},
49 {.field_id = "modsig", .field_init = ima_eventmodsig_init,
50 .field_show = ima_show_template_sig},
51 {.field_id = "evmsig", .field_init = ima_eventevmsig_init,
52 .field_show = ima_show_template_sig},
53 {.field_id = "iuid", .field_init = ima_eventinodeuid_init,
54 .field_show = ima_show_template_uint},
55 {.field_id = "igid", .field_init = ima_eventinodegid_init,
56 .field_show = ima_show_template_uint},
57 {.field_id = "imode", .field_init = ima_eventinodemode_init,
58 .field_show = ima_show_template_uint},
59 {.field_id = "xattrnames",
60 .field_init = ima_eventinodexattrnames_init,
61 .field_show = ima_show_template_string},
62 {.field_id = "xattrlengths",
63 .field_init = ima_eventinodexattrlengths_init,
64 .field_show = ima_show_template_sig},
65 {.field_id = "xattrvalues",
66 .field_init = ima_eventinodexattrvalues_init,
67 .field_show = ima_show_template_sig},
68};
69
70
71
72
73
74
75#define MAX_TEMPLATE_NAME_LEN \
76 sizeof("d-ng|n-ng|evmsig|xattrnames|xattrlengths|xattrvalues|iuid|igid|imode")
77
78static struct ima_template_desc *ima_template;
79static struct ima_template_desc *ima_buf_template;
80
81
82
83
84
85
86
87
88bool ima_template_has_modsig(const struct ima_template_desc *ima_template)
89{
90 int i;
91
92 for (i = 0; i < ima_template->num_fields; i++)
93 if (!strcmp(ima_template->fields[i]->field_id, "modsig") ||
94 !strcmp(ima_template->fields[i]->field_id, "d-modsig"))
95 return true;
96
97 return false;
98}
99
100static int __init ima_template_setup(char *str)
101{
102 struct ima_template_desc *template_desc;
103 int template_len = strlen(str);
104
105 if (template_setup_done)
106 return 1;
107
108 if (!ima_template)
109 ima_init_template_list();
110
111
112
113
114
115 template_desc = lookup_template_desc(str);
116 if (!template_desc) {
117 pr_err("template %s not found, using %s\n",
118 str, CONFIG_IMA_DEFAULT_TEMPLATE);
119 return 1;
120 }
121
122
123
124
125
126 if (template_len == 3 && strcmp(str, IMA_TEMPLATE_IMA_NAME) == 0 &&
127 ima_hash_algo != HASH_ALGO_SHA1 && ima_hash_algo != HASH_ALGO_MD5) {
128 pr_err("template does not support hash alg\n");
129 return 1;
130 }
131
132 ima_template = template_desc;
133 template_setup_done = 1;
134 return 1;
135}
136__setup("ima_template=", ima_template_setup);
137
138static int __init ima_template_fmt_setup(char *str)
139{
140 int num_templates = ARRAY_SIZE(builtin_templates);
141
142 if (template_setup_done)
143 return 1;
144
145 if (template_desc_init_fields(str, NULL, NULL) < 0) {
146 pr_err("format string '%s' not valid, using template %s\n",
147 str, CONFIG_IMA_DEFAULT_TEMPLATE);
148 return 1;
149 }
150
151 builtin_templates[num_templates - 1].fmt = str;
152 ima_template = builtin_templates + num_templates - 1;
153 template_setup_done = 1;
154
155 return 1;
156}
157__setup("ima_template_fmt=", ima_template_fmt_setup);
158
159struct ima_template_desc *lookup_template_desc(const char *name)
160{
161 struct ima_template_desc *template_desc;
162 int found = 0;
163
164 rcu_read_lock();
165 list_for_each_entry_rcu(template_desc, &defined_templates, list) {
166 if ((strcmp(template_desc->name, name) == 0) ||
167 (strcmp(template_desc->fmt, name) == 0)) {
168 found = 1;
169 break;
170 }
171 }
172 rcu_read_unlock();
173 return found ? template_desc : NULL;
174}
175
176static const struct ima_template_field *
177lookup_template_field(const char *field_id)
178{
179 int i;
180
181 for (i = 0; i < ARRAY_SIZE(supported_fields); i++)
182 if (strncmp(supported_fields[i].field_id, field_id,
183 IMA_TEMPLATE_FIELD_ID_MAX_LEN) == 0)
184 return &supported_fields[i];
185 return NULL;
186}
187
188static int template_fmt_size(const char *template_fmt)
189{
190 char c;
191 int template_fmt_len = strlen(template_fmt);
192 int i = 0, j = 0;
193
194 while (i < template_fmt_len) {
195 c = template_fmt[i];
196 if (c == '|')
197 j++;
198 i++;
199 }
200
201 return j + 1;
202}
203
204int template_desc_init_fields(const char *template_fmt,
205 const struct ima_template_field ***fields,
206 int *num_fields)
207{
208 const char *template_fmt_ptr;
209 const struct ima_template_field *found_fields[IMA_TEMPLATE_NUM_FIELDS_MAX];
210 int template_num_fields;
211 int i, len;
212
213 if (num_fields && *num_fields > 0)
214 return 0;
215
216 template_num_fields = template_fmt_size(template_fmt);
217
218 if (template_num_fields > IMA_TEMPLATE_NUM_FIELDS_MAX) {
219 pr_err("format string '%s' contains too many fields\n",
220 template_fmt);
221 return -EINVAL;
222 }
223
224 for (i = 0, template_fmt_ptr = template_fmt; i < template_num_fields;
225 i++, template_fmt_ptr += len + 1) {
226 char tmp_field_id[IMA_TEMPLATE_FIELD_ID_MAX_LEN + 1];
227
228 len = strchrnul(template_fmt_ptr, '|') - template_fmt_ptr;
229 if (len == 0 || len > IMA_TEMPLATE_FIELD_ID_MAX_LEN) {
230 pr_err("Invalid field with length %d\n", len);
231 return -EINVAL;
232 }
233
234 memcpy(tmp_field_id, template_fmt_ptr, len);
235 tmp_field_id[len] = '\0';
236 found_fields[i] = lookup_template_field(tmp_field_id);
237 if (!found_fields[i]) {
238 pr_err("field '%s' not found\n", tmp_field_id);
239 return -ENOENT;
240 }
241 }
242
243 if (fields && num_fields) {
244 *fields = kmalloc_array(i, sizeof(*fields), GFP_KERNEL);
245 if (*fields == NULL)
246 return -ENOMEM;
247
248 memcpy(*fields, found_fields, i * sizeof(*fields));
249 *num_fields = i;
250 }
251
252 return 0;
253}
254
255void ima_init_template_list(void)
256{
257 int i;
258
259 if (!list_empty(&defined_templates))
260 return;
261
262 spin_lock(&template_list);
263 for (i = 0; i < ARRAY_SIZE(builtin_templates); i++) {
264 list_add_tail_rcu(&builtin_templates[i].list,
265 &defined_templates);
266 }
267 spin_unlock(&template_list);
268}
269
270struct ima_template_desc *ima_template_desc_current(void)
271{
272 if (!ima_template) {
273 ima_init_template_list();
274 ima_template =
275 lookup_template_desc(CONFIG_IMA_DEFAULT_TEMPLATE);
276 }
277 return ima_template;
278}
279
280struct ima_template_desc *ima_template_desc_buf(void)
281{
282 if (!ima_buf_template) {
283 ima_init_template_list();
284 ima_buf_template = lookup_template_desc("ima-buf");
285 }
286 return ima_buf_template;
287}
288
289int __init ima_init_template(void)
290{
291 struct ima_template_desc *template = ima_template_desc_current();
292 int result;
293
294 result = template_desc_init_fields(template->fmt,
295 &(template->fields),
296 &(template->num_fields));
297 if (result < 0) {
298 pr_err("template %s init failed, result: %d\n",
299 (strlen(template->name) ?
300 template->name : template->fmt), result);
301 return result;
302 }
303
304 template = ima_template_desc_buf();
305 if (!template) {
306 pr_err("Failed to get ima-buf template\n");
307 return -EINVAL;
308 }
309
310 result = template_desc_init_fields(template->fmt,
311 &(template->fields),
312 &(template->num_fields));
313 if (result < 0)
314 pr_err("template %s init failed, result: %d\n",
315 (strlen(template->name) ?
316 template->name : template->fmt), result);
317
318 return result;
319}
320
321static struct ima_template_desc *restore_template_fmt(char *template_name)
322{
323 struct ima_template_desc *template_desc = NULL;
324 int ret;
325
326 ret = template_desc_init_fields(template_name, NULL, NULL);
327 if (ret < 0) {
328 pr_err("attempting to initialize the template \"%s\" failed\n",
329 template_name);
330 goto out;
331 }
332
333 template_desc = kzalloc(sizeof(*template_desc), GFP_KERNEL);
334 if (!template_desc)
335 goto out;
336
337 template_desc->name = "";
338 template_desc->fmt = kstrdup(template_name, GFP_KERNEL);
339 if (!template_desc->fmt)
340 goto out;
341
342 spin_lock(&template_list);
343 list_add_tail_rcu(&template_desc->list, &defined_templates);
344 spin_unlock(&template_list);
345out:
346 return template_desc;
347}
348
349static int ima_restore_template_data(struct ima_template_desc *template_desc,
350 void *template_data,
351 int template_data_size,
352 struct ima_template_entry **entry)
353{
354 struct tpm_digest *digests;
355 int ret = 0;
356 int i;
357
358 *entry = kzalloc(struct_size(*entry, template_data,
359 template_desc->num_fields), GFP_NOFS);
360 if (!*entry)
361 return -ENOMEM;
362
363 digests = kcalloc(NR_BANKS(ima_tpm_chip) + ima_extra_slots,
364 sizeof(*digests), GFP_NOFS);
365 if (!digests) {
366 kfree(*entry);
367 return -ENOMEM;
368 }
369
370 (*entry)->digests = digests;
371
372 ret = ima_parse_buf(template_data, template_data + template_data_size,
373 NULL, template_desc->num_fields,
374 (*entry)->template_data, NULL, NULL,
375 ENFORCE_FIELDS | ENFORCE_BUFEND, "template data");
376 if (ret < 0) {
377 kfree((*entry)->digests);
378 kfree(*entry);
379 return ret;
380 }
381
382 (*entry)->template_desc = template_desc;
383 for (i = 0; i < template_desc->num_fields; i++) {
384 struct ima_field_data *field_data = &(*entry)->template_data[i];
385 u8 *data = field_data->data;
386
387 (*entry)->template_data[i].data =
388 kzalloc(field_data->len + 1, GFP_KERNEL);
389 if (!(*entry)->template_data[i].data) {
390 ret = -ENOMEM;
391 break;
392 }
393 memcpy((*entry)->template_data[i].data, data, field_data->len);
394 (*entry)->template_data_len += sizeof(field_data->len);
395 (*entry)->template_data_len += field_data->len;
396 }
397
398 if (ret < 0) {
399 ima_free_template_entry(*entry);
400 *entry = NULL;
401 }
402
403 return ret;
404}
405
406
407int ima_restore_measurement_list(loff_t size, void *buf)
408{
409 char template_name[MAX_TEMPLATE_NAME_LEN];
410 unsigned char zero[TPM_DIGEST_SIZE] = { 0 };
411
412 struct ima_kexec_hdr *khdr = buf;
413 struct ima_field_data hdr[HDR__LAST] = {
414 [HDR_PCR] = {.len = sizeof(u32)},
415 [HDR_DIGEST] = {.len = TPM_DIGEST_SIZE},
416 };
417
418 void *bufp = buf + sizeof(*khdr);
419 void *bufendp;
420 struct ima_template_entry *entry;
421 struct ima_template_desc *template_desc;
422 DECLARE_BITMAP(hdr_mask, HDR__LAST);
423 unsigned long count = 0;
424 int ret = 0;
425
426 if (!buf || size < sizeof(*khdr))
427 return 0;
428
429 if (ima_canonical_fmt) {
430 khdr->version = le16_to_cpu((__force __le16)khdr->version);
431 khdr->count = le64_to_cpu((__force __le64)khdr->count);
432 khdr->buffer_size = le64_to_cpu((__force __le64)khdr->buffer_size);
433 }
434
435 if (khdr->version != 1) {
436 pr_err("attempting to restore a incompatible measurement list");
437 return -EINVAL;
438 }
439
440 if (khdr->count > ULONG_MAX - 1) {
441 pr_err("attempting to restore too many measurements");
442 return -EINVAL;
443 }
444
445 bitmap_zero(hdr_mask, HDR__LAST);
446 bitmap_set(hdr_mask, HDR_PCR, 1);
447 bitmap_set(hdr_mask, HDR_DIGEST, 1);
448
449
450
451
452
453
454 bufendp = buf + khdr->buffer_size;
455 while ((bufp < bufendp) && (count++ < khdr->count)) {
456 int enforce_mask = ENFORCE_FIELDS;
457
458 enforce_mask |= (count == khdr->count) ? ENFORCE_BUFEND : 0;
459 ret = ima_parse_buf(bufp, bufendp, &bufp, HDR__LAST, hdr, NULL,
460 hdr_mask, enforce_mask, "entry header");
461 if (ret < 0)
462 break;
463
464 if (hdr[HDR_TEMPLATE_NAME].len >= MAX_TEMPLATE_NAME_LEN) {
465 pr_err("attempting to restore a template name that is too long\n");
466 ret = -EINVAL;
467 break;
468 }
469
470
471 memcpy(template_name, hdr[HDR_TEMPLATE_NAME].data,
472 hdr[HDR_TEMPLATE_NAME].len);
473 template_name[hdr[HDR_TEMPLATE_NAME].len] = 0;
474
475 if (strcmp(template_name, "ima") == 0) {
476 pr_err("attempting to restore an unsupported template \"%s\" failed\n",
477 template_name);
478 ret = -EINVAL;
479 break;
480 }
481
482 template_desc = lookup_template_desc(template_name);
483 if (!template_desc) {
484 template_desc = restore_template_fmt(template_name);
485 if (!template_desc)
486 break;
487 }
488
489
490
491
492
493 ret = template_desc_init_fields(template_desc->fmt,
494 &(template_desc->fields),
495 &(template_desc->num_fields));
496 if (ret < 0) {
497 pr_err("attempting to restore the template fmt \"%s\" failed\n",
498 template_desc->fmt);
499 ret = -EINVAL;
500 break;
501 }
502
503 ret = ima_restore_template_data(template_desc,
504 hdr[HDR_TEMPLATE_DATA].data,
505 hdr[HDR_TEMPLATE_DATA].len,
506 &entry);
507 if (ret < 0)
508 break;
509
510 if (memcmp(hdr[HDR_DIGEST].data, zero, sizeof(zero))) {
511 ret = ima_calc_field_array_hash(
512 &entry->template_data[0],
513 entry);
514 if (ret < 0) {
515 pr_err("cannot calculate template digest\n");
516 ret = -EINVAL;
517 break;
518 }
519 }
520
521 entry->pcr = !ima_canonical_fmt ? *(u32 *)(hdr[HDR_PCR].data) :
522 le32_to_cpu(*(__le32 *)(hdr[HDR_PCR].data));
523 ret = ima_restore_measurement_entry(entry);
524 if (ret < 0)
525 break;
526
527 }
528 return ret;
529}
530
