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