ima_template_lib.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2013 Politecnico di Torino, Italy
  4 *                    TORSEC group -- https://security.polito.it
  5 *
  6 * Author: Roberto Sassu <roberto.sassu@polito.it>
  7 *
  8 * File: ima_template_lib.c
  9 *      Library of supported template fields.
 10 */
 11
 12#include "ima_template_lib.h"
 13#include <linux/xattr.h>
 14#include <linux/evm.h>
 15
 16static bool ima_template_hash_algo_allowed(u8 algo)
 17{
 18	if (algo == HASH_ALGO_SHA1 || algo == HASH_ALGO_MD5)
 19		return true;
 20
 21	return false;
 22}
 23
 24enum data_formats {
 25	DATA_FMT_DIGEST = 0,
 26	DATA_FMT_DIGEST_WITH_ALGO,
 27	DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO,
 28	DATA_FMT_STRING,
 29	DATA_FMT_HEX,
 30	DATA_FMT_UINT
 31};
 32
 33enum digest_type {
 34	DIGEST_TYPE_IMA,
 35	DIGEST_TYPE_VERITY,
 36	DIGEST_TYPE__LAST
 37};
 38
 39#define DIGEST_TYPE_NAME_LEN_MAX 7	/* including NUL */
 40static const char * const digest_type_name[DIGEST_TYPE__LAST] = {
 41	[DIGEST_TYPE_IMA] = "ima",
 42	[DIGEST_TYPE_VERITY] = "verity"
 43};
 44
 45static int ima_write_template_field_data(const void *data, const u32 datalen,
 46					 enum data_formats datafmt,
 47					 struct ima_field_data *field_data)
 48{
 49	u8 *buf, *buf_ptr;
 50	u32 buflen = datalen;
 51
 52	if (datafmt == DATA_FMT_STRING)
 53		buflen = datalen + 1;
 54
 55	buf = kzalloc(buflen, GFP_KERNEL);
 56	if (!buf)
 57		return -ENOMEM;
 58
 59	memcpy(buf, data, datalen);
 60
 61	/*
 62	 * Replace all space characters with underscore for event names and
 63	 * strings. This avoid that, during the parsing of a measurements list,
 64	 * filenames with spaces or that end with the suffix ' (deleted)' are
 65	 * split into multiple template fields (the space is the delimitator
 66	 * character for measurements lists in ASCII format).
 67	 */
 68	if (datafmt == DATA_FMT_STRING) {
 69		for (buf_ptr = buf; buf_ptr - buf < datalen; buf_ptr++)
 70			if (*buf_ptr == ' ')
 71				*buf_ptr = '_';
 72	}
 73
 74	field_data->data = buf;
 75	field_data->len = buflen;
 76	return 0;
 77}
 78
 79static void ima_show_template_data_ascii(struct seq_file *m,
 80					 enum ima_show_type show,
 81					 enum data_formats datafmt,
 82					 struct ima_field_data *field_data)
 83{
 84	u8 *buf_ptr = field_data->data;
 85	u32 buflen = field_data->len;
 86
 87	switch (datafmt) {
 88	case DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO:
 89	case DATA_FMT_DIGEST_WITH_ALGO:
 90		buf_ptr = strrchr(field_data->data, ':');
 91		if (buf_ptr != field_data->data)
 92			seq_printf(m, "%s", field_data->data);
 93
 94		/* skip ':' and '\0' */
 95		buf_ptr += 2;
 96		buflen -= buf_ptr - field_data->data;
 97		fallthrough;
 98	case DATA_FMT_DIGEST:
 99	case DATA_FMT_HEX:
100		if (!buflen)
101			break;
102		ima_print_digest(m, buf_ptr, buflen);
103		break;
104	case DATA_FMT_STRING:
105		seq_printf(m, "%s", buf_ptr);
106		break;
107	case DATA_FMT_UINT:
108		switch (field_data->len) {
109		case sizeof(u8):
110			seq_printf(m, "%u", *(u8 *)buf_ptr);
111			break;
112		case sizeof(u16):
113			if (ima_canonical_fmt)
114				seq_printf(m, "%u",
115					   le16_to_cpu(*(__le16 *)buf_ptr));
116			else
117				seq_printf(m, "%u", *(u16 *)buf_ptr);
118			break;
119		case sizeof(u32):
120			if (ima_canonical_fmt)
121				seq_printf(m, "%u",
122					   le32_to_cpu(*(__le32 *)buf_ptr));
123			else
124				seq_printf(m, "%u", *(u32 *)buf_ptr);
125			break;
126		case sizeof(u64):
127			if (ima_canonical_fmt)
128				seq_printf(m, "%llu",
129					   le64_to_cpu(*(__le64 *)buf_ptr));
130			else
131				seq_printf(m, "%llu", *(u64 *)buf_ptr);
132			break;
133		default:
134			break;
135		}
136		break;
137	default:
138		break;
139	}
140}
141
142static void ima_show_template_data_binary(struct seq_file *m,
143					  enum ima_show_type show,
144					  enum data_formats datafmt,
145					  struct ima_field_data *field_data)
146{
147	u32 len = (show == IMA_SHOW_BINARY_OLD_STRING_FMT) ?
148	    strlen(field_data->data) : field_data->len;
149
150	if (show != IMA_SHOW_BINARY_NO_FIELD_LEN) {
151		u32 field_len = !ima_canonical_fmt ?
152				len : (__force u32)cpu_to_le32(len);
153
154		ima_putc(m, &field_len, sizeof(field_len));
155	}
156
157	if (!len)
158		return;
159
160	ima_putc(m, field_data->data, len);
161}
162
163static void ima_show_template_field_data(struct seq_file *m,
164					 enum ima_show_type show,
165					 enum data_formats datafmt,
166					 struct ima_field_data *field_data)
167{
168	switch (show) {
169	case IMA_SHOW_ASCII:
170		ima_show_template_data_ascii(m, show, datafmt, field_data);
171		break;
172	case IMA_SHOW_BINARY:
173	case IMA_SHOW_BINARY_NO_FIELD_LEN:
174	case IMA_SHOW_BINARY_OLD_STRING_FMT:
175		ima_show_template_data_binary(m, show, datafmt, field_data);
176		break;
177	default:
178		break;
179	}
180}
181
182void ima_show_template_digest(struct seq_file *m, enum ima_show_type show,
183			      struct ima_field_data *field_data)
184{
185	ima_show_template_field_data(m, show, DATA_FMT_DIGEST, field_data);
186}
187
188void ima_show_template_digest_ng(struct seq_file *m, enum ima_show_type show,
189				 struct ima_field_data *field_data)
190{
191	ima_show_template_field_data(m, show, DATA_FMT_DIGEST_WITH_ALGO,
192				     field_data);
193}
194
195void ima_show_template_digest_ngv2(struct seq_file *m, enum ima_show_type show,
196				   struct ima_field_data *field_data)
197{
198	ima_show_template_field_data(m, show,
199				     DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO,
200				     field_data);
201}
202
203void ima_show_template_string(struct seq_file *m, enum ima_show_type show,
204			      struct ima_field_data *field_data)
205{
206	ima_show_template_field_data(m, show, DATA_FMT_STRING, field_data);
207}
208
209void ima_show_template_sig(struct seq_file *m, enum ima_show_type show,
210			   struct ima_field_data *field_data)
211{
212	ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data);
213}
214
215void ima_show_template_buf(struct seq_file *m, enum ima_show_type show,
216			   struct ima_field_data *field_data)
217{
218	ima_show_template_field_data(m, show, DATA_FMT_HEX, field_data);
219}
220
221void ima_show_template_uint(struct seq_file *m, enum ima_show_type show,
222			    struct ima_field_data *field_data)
223{
224	ima_show_template_field_data(m, show, DATA_FMT_UINT, field_data);
225}
226
227/**
228 * ima_parse_buf() - Parses lengths and data from an input buffer
229 * @bufstartp:       Buffer start address.
230 * @bufendp:         Buffer end address.
231 * @bufcurp:         Pointer to remaining (non-parsed) data.
232 * @maxfields:       Length of fields array.
233 * @fields:          Array containing lengths and pointers of parsed data.
234 * @curfields:       Number of array items containing parsed data.
235 * @len_mask:        Bitmap (if bit is set, data length should not be parsed).
236 * @enforce_mask:    Check if curfields == maxfields and/or bufcurp == bufendp.
237 * @bufname:         String identifier of the input buffer.
238 *
239 * Return: 0 on success, -EINVAL on error.
240 */
241int ima_parse_buf(void *bufstartp, void *bufendp, void **bufcurp,
242		  int maxfields, struct ima_field_data *fields, int *curfields,
243		  unsigned long *len_mask, int enforce_mask, char *bufname)
244{
245	void *bufp = bufstartp;
246	int i;
247
248	for (i = 0; i < maxfields; i++) {
249		if (len_mask == NULL || !test_bit(i, len_mask)) {
250			if (bufp > (bufendp - sizeof(u32)))
251				break;
252
253			if (ima_canonical_fmt)
254				fields[i].len = le32_to_cpu(*(__le32 *)bufp);
255			else
256				fields[i].len = *(u32 *)bufp;
257
258			bufp += sizeof(u32);
259		}
260
261		if (bufp > (bufendp - fields[i].len))
262			break;
263
264		fields[i].data = bufp;
265		bufp += fields[i].len;
266	}
267
268	if ((enforce_mask & ENFORCE_FIELDS) && i != maxfields) {
269		pr_err("%s: nr of fields mismatch: expected: %d, current: %d\n",
270		       bufname, maxfields, i);
271		return -EINVAL;
272	}
273
274	if ((enforce_mask & ENFORCE_BUFEND) && bufp != bufendp) {
275		pr_err("%s: buf end mismatch: expected: %p, current: %p\n",
276		       bufname, bufendp, bufp);
277		return -EINVAL;
278	}
279
280	if (curfields)
281		*curfields = i;
282
283	if (bufcurp)
284		*bufcurp = bufp;
285
286	return 0;
287}
288
289static int ima_eventdigest_init_common(const u8 *digest, u32 digestsize,
290				       u8 digest_type, u8 hash_algo,
291				       struct ima_field_data *field_data)
292{
293	/*
294	 * digest formats:
295	 *  - DATA_FMT_DIGEST: digest
296	 *  - DATA_FMT_DIGEST_WITH_ALGO: <hash algo> + ':' + '\0' + digest,
297	 *  - DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO:
298	 *	<digest type> + ':' + <hash algo> + ':' + '\0' + digest,
299	 *
300	 *    where 'DATA_FMT_DIGEST' is the original digest format ('d')
301	 *      with a hash size limitation of 20 bytes,
302	 *    where <digest type> is either "ima" or "verity",
303	 *    where <hash algo> is the hash_algo_name[] string.
304	 */
305	u8 buffer[DIGEST_TYPE_NAME_LEN_MAX + CRYPTO_MAX_ALG_NAME + 2 +
306		IMA_MAX_DIGEST_SIZE] = { 0 };
307	enum data_formats fmt = DATA_FMT_DIGEST;
308	u32 offset = 0;
309
310	if (digest_type < DIGEST_TYPE__LAST && hash_algo < HASH_ALGO__LAST) {
311		fmt = DATA_FMT_DIGEST_WITH_TYPE_AND_ALGO;
312		offset += 1 + sprintf(buffer, "%s:%s:",
313				      digest_type_name[digest_type],
314				      hash_algo_name[hash_algo]);
315	} else if (hash_algo < HASH_ALGO__LAST) {
316		fmt = DATA_FMT_DIGEST_WITH_ALGO;
317		offset += 1 + sprintf(buffer, "%s:",
318				      hash_algo_name[hash_algo]);
319	}
320
321	if (digest) {
322		memcpy(buffer + offset, digest, digestsize);
323	} else {
324		/*
325		 * If digest is NULL, the event being recorded is a violation.
326		 * Make room for the digest by increasing the offset by the
327		 * hash algorithm digest size. If the hash algorithm is not
328		 * specified increase the offset by IMA_DIGEST_SIZE which
329		 * fits SHA1 or MD5
330		 */
331		if (hash_algo < HASH_ALGO__LAST)
332			offset += hash_digest_size[hash_algo];
333		else
334			offset += IMA_DIGEST_SIZE;
335	}
336
337	return ima_write_template_field_data(buffer, offset + digestsize,
338					     fmt, field_data);
339}
340
341/*
342 * This function writes the digest of an event (with size limit).
343 */
344int ima_eventdigest_init(struct ima_event_data *event_data,
345			 struct ima_field_data *field_data)
346{
347	struct ima_max_digest_data hash;
348	struct ima_digest_data *hash_hdr = container_of(&hash.hdr,
349						struct ima_digest_data, hdr);
350	u8 *cur_digest = NULL;
351	u32 cur_digestsize = 0;
352	struct inode *inode;
353	int result;
354
355	memset(&hash, 0, sizeof(hash));
356
357	if (event_data->violation)	/* recording a violation. */
358		goto out;
359
360	if (ima_template_hash_algo_allowed(event_data->iint->ima_hash->algo)) {
361		cur_digest = event_data->iint->ima_hash->digest;
362		cur_digestsize = event_data->iint->ima_hash->length;
363		goto out;
364	}
365
366	if ((const char *)event_data->filename == boot_aggregate_name) {
367		if (ima_tpm_chip) {
368			hash.hdr.algo = HASH_ALGO_SHA1;
369			result = ima_calc_boot_aggregate(hash_hdr);
370
371			/* algo can change depending on available PCR banks */
372			if (!result && hash.hdr.algo != HASH_ALGO_SHA1)
373				result = -EINVAL;
374
375			if (result < 0)
376				memset(&hash, 0, sizeof(hash));
377		}
378
379		cur_digest = hash_hdr->digest;
380		cur_digestsize = hash_digest_size[HASH_ALGO_SHA1];
381		goto out;
382	}
383
384	if (!event_data->file)	/* missing info to re-calculate the digest */
385		return -EINVAL;
386
387	inode = file_inode(event_data->file);
388	hash.hdr.algo = ima_template_hash_algo_allowed(ima_hash_algo) ?
389	    ima_hash_algo : HASH_ALGO_SHA1;
390	result = ima_calc_file_hash(event_data->file, hash_hdr);
391	if (result) {
392		integrity_audit_msg(AUDIT_INTEGRITY_DATA, inode,
393				    event_data->filename, "collect_data",
394				    "failed", result, 0);
395		return result;
396	}
397	cur_digest = hash_hdr->digest;
398	cur_digestsize = hash.hdr.length;
399out:
400	return ima_eventdigest_init_common(cur_digest, cur_digestsize,
401					   DIGEST_TYPE__LAST, HASH_ALGO__LAST,
402					   field_data);
403}
404
405/*
406 * This function writes the digest of an event (without size limit).
407 */
408int ima_eventdigest_ng_init(struct ima_event_data *event_data,
409			    struct ima_field_data *field_data)
410{
411	u8 *cur_digest = NULL, hash_algo = ima_hash_algo;
412	u32 cur_digestsize = 0;
413
414	if (event_data->violation)	/* recording a violation. */
415		goto out;
416
417	cur_digest = event_data->iint->ima_hash->digest;
418	cur_digestsize = event_data->iint->ima_hash->length;
419
420	hash_algo = event_data->iint->ima_hash->algo;
421out:
422	return ima_eventdigest_init_common(cur_digest, cur_digestsize,
423					   DIGEST_TYPE__LAST, hash_algo,
424					   field_data);
425}
426
427/*
428 * This function writes the digest of an event (without size limit),
429 * prefixed with both the digest type and hash algorithm.
430 */
431int ima_eventdigest_ngv2_init(struct ima_event_data *event_data,
432			      struct ima_field_data *field_data)
433{
434	u8 *cur_digest = NULL, hash_algo = ima_hash_algo;
435	u32 cur_digestsize = 0;
436	u8 digest_type = DIGEST_TYPE_IMA;
437
438	if (event_data->violation)	/* recording a violation. */
439		goto out;
440
441	cur_digest = event_data->iint->ima_hash->digest;
442	cur_digestsize = event_data->iint->ima_hash->length;
443
444	hash_algo = event_data->iint->ima_hash->algo;
445	if (event_data->iint->flags & IMA_VERITY_REQUIRED)
446		digest_type = DIGEST_TYPE_VERITY;
447out:
448	return ima_eventdigest_init_common(cur_digest, cur_digestsize,
449					   digest_type, hash_algo,
450					   field_data);
451}
452
453/*
454 * This function writes the digest of the file which is expected to match the
455 * digest contained in the file's appended signature.
456 */
457int ima_eventdigest_modsig_init(struct ima_event_data *event_data,
458				struct ima_field_data *field_data)
459{
460	enum hash_algo hash_algo;
461	const u8 *cur_digest;
462	u32 cur_digestsize;
463
464	if (!event_data->modsig)
465		return 0;
466
467	if (event_data->violation) {
468		/* Recording a violation. */
469		hash_algo = HASH_ALGO_SHA1;
470		cur_digest = NULL;
471		cur_digestsize = 0;
472	} else {
473		int rc;
474
475		rc = ima_get_modsig_digest(event_data->modsig, &hash_algo,
476					   &cur_digest, &cur_digestsize);
477		if (rc)
478			return rc;
479		else if (hash_algo == HASH_ALGO__LAST || cur_digestsize == 0)
480			/* There was some error collecting the digest. */
481			return -EINVAL;
482	}
483
484	return ima_eventdigest_init_common(cur_digest, cur_digestsize,
485					   DIGEST_TYPE__LAST, hash_algo,
486					   field_data);
487}
488
489static int ima_eventname_init_common(struct ima_event_data *event_data,
490				     struct ima_field_data *field_data,
491				     bool size_limit)
492{
493	const char *cur_filename = NULL;
494	struct name_snapshot filename;
495	u32 cur_filename_len = 0;
496	bool snapshot = false;
497	int ret;
498
499	BUG_ON(event_data->filename == NULL && event_data->file == NULL);
500
501	if (event_data->filename) {
502		cur_filename = event_data->filename;
503		cur_filename_len = strlen(event_data->filename);
504
505		if (!size_limit || cur_filename_len <= IMA_EVENT_NAME_LEN_MAX)
506			goto out;
507	}
508
509	if (event_data->file) {
510		take_dentry_name_snapshot(&filename,
511					  event_data->file->f_path.dentry);
512		snapshot = true;
513		cur_filename = filename.name.name;
514		cur_filename_len = strlen(cur_filename);
515	} else
516		/*
517		 * Truncate filename if the latter is too long and
518		 * the file descriptor is not available.
519		 */
520		cur_filename_len = IMA_EVENT_NAME_LEN_MAX;
521out:
522	ret = ima_write_template_field_data(cur_filename, cur_filename_len,
523					    DATA_FMT_STRING, field_data);
524
525	if (snapshot)
526		release_dentry_name_snapshot(&filename);
527
528	return ret;
529}
530
531/*
532 * This function writes the name of an event (with size limit).
533 */
534int ima_eventname_init(struct ima_event_data *event_data,
535		       struct ima_field_data *field_data)
536{
537	return ima_eventname_init_common(event_data, field_data, true);
538}
539
540/*
541 * This function writes the name of an event (without size limit).
542 */
543int ima_eventname_ng_init(struct ima_event_data *event_data,
544			  struct ima_field_data *field_data)
545{
546	return ima_eventname_init_common(event_data, field_data, false);
547}
548
549/*
550 *  ima_eventsig_init - include the file signature as part of the template data
551 */
552int ima_eventsig_init(struct ima_event_data *event_data,
553		      struct ima_field_data *field_data)
554{
555	struct evm_ima_xattr_data *xattr_value = event_data->xattr_value;
556
557	if (!xattr_value ||
558	    (xattr_value->type != EVM_IMA_XATTR_DIGSIG &&
559	     xattr_value->type != IMA_VERITY_DIGSIG))
560		return ima_eventevmsig_init(event_data, field_data);
561
562	return ima_write_template_field_data(xattr_value, event_data->xattr_len,
563					     DATA_FMT_HEX, field_data);
564}
565
566/*
567 *  ima_eventbuf_init - include the buffer(kexec-cmldine) as part of the
568 *  template data.
569 */
570int ima_eventbuf_init(struct ima_event_data *event_data,
571		      struct ima_field_data *field_data)
572{
573	if ((!event_data->buf) || (event_data->buf_len == 0))
574		return 0;
575
576	return ima_write_template_field_data(event_data->buf,
577					     event_data->buf_len, DATA_FMT_HEX,
578					     field_data);
579}
580
581/*
582 *  ima_eventmodsig_init - include the appended file signature as part of the
583 *  template data
584 */
585int ima_eventmodsig_init(struct ima_event_data *event_data,
586			 struct ima_field_data *field_data)
587{
588	const void *data;
589	u32 data_len;
590	int rc;
591
592	if (!event_data->modsig)
593		return 0;
594
595	/*
596	 * modsig is a runtime structure containing pointers. Get its raw data
597	 * instead.
598	 */
599	rc = ima_get_raw_modsig(event_data->modsig, &data, &data_len);
600	if (rc)
601		return rc;
602
603	return ima_write_template_field_data(data, data_len, DATA_FMT_HEX,
604					     field_data);
605}
606
607/*
608 *  ima_eventevmsig_init - include the EVM portable signature as part of the
609 *  template data
610 */
611int ima_eventevmsig_init(struct ima_event_data *event_data,
612			 struct ima_field_data *field_data)
613{
614	struct evm_ima_xattr_data *xattr_data = NULL;
615	int rc = 0;
616
617	if (!event_data->file)
618		return 0;
619
620	rc = vfs_getxattr_alloc(&nop_mnt_idmap, file_dentry(event_data->file),
621				XATTR_NAME_EVM, (char **)&xattr_data, 0,
622				GFP_NOFS);
623	if (rc <= 0 || xattr_data->type != EVM_XATTR_PORTABLE_DIGSIG) {
624		rc = 0;
625		goto out;
626	}
627
628	rc = ima_write_template_field_data((char *)xattr_data, rc, DATA_FMT_HEX,
629					   field_data);
630
631out:
632	kfree(xattr_data);
633	return rc;
634}
635
636static int ima_eventinodedac_init_common(struct ima_event_data *event_data,
637					 struct ima_field_data *field_data,
638					 bool get_uid)
639{
640	unsigned int id;
641
642	if (!event_data->file)
643		return 0;
644
645	if (get_uid)
646		id = i_uid_read(file_inode(event_data->file));
647	else
648		id = i_gid_read(file_inode(event_data->file));
649
650	if (ima_canonical_fmt) {
651		if (sizeof(id) == sizeof(u16))
652			id = (__force u16)cpu_to_le16(id);
653		else
654			id = (__force u32)cpu_to_le32(id);
655	}
656
657	return ima_write_template_field_data((void *)&id, sizeof(id),
658					     DATA_FMT_UINT, field_data);
659}
660
661/*
662 *  ima_eventinodeuid_init - include the inode UID as part of the template
663 *  data
664 */
665int ima_eventinodeuid_init(struct ima_event_data *event_data,
666			   struct ima_field_data *field_data)
667{
668	return ima_eventinodedac_init_common(event_data, field_data, true);
669}
670
671/*
672 *  ima_eventinodegid_init - include the inode GID as part of the template
673 *  data
674 */
675int ima_eventinodegid_init(struct ima_event_data *event_data,
676			   struct ima_field_data *field_data)
677{
678	return ima_eventinodedac_init_common(event_data, field_data, false);
679}
680
681/*
682 *  ima_eventinodemode_init - include the inode mode as part of the template
683 *  data
684 */
685int ima_eventinodemode_init(struct ima_event_data *event_data,
686			    struct ima_field_data *field_data)
687{
688	struct inode *inode;
689	u16 mode;
690
691	if (!event_data->file)
692		return 0;
693
694	inode = file_inode(event_data->file);
695	mode = inode->i_mode;
696	if (ima_canonical_fmt)
697		mode = (__force u16)cpu_to_le16(mode);
698
699	return ima_write_template_field_data((char *)&mode, sizeof(mode),
700					     DATA_FMT_UINT, field_data);
701}
702
703static int ima_eventinodexattrs_init_common(struct ima_event_data *event_data,
704					    struct ima_field_data *field_data,
705					    char type)
706{
707	u8 *buffer = NULL;
708	int rc;
709
710	if (!event_data->file)
711		return 0;
712
713	rc = evm_read_protected_xattrs(file_dentry(event_data->file), NULL, 0,
714				       type, ima_canonical_fmt);
715	if (rc < 0)
716		return 0;
717
718	buffer = kmalloc(rc, GFP_KERNEL);
719	if (!buffer)
720		return 0;
721
722	rc = evm_read_protected_xattrs(file_dentry(event_data->file), buffer,
723				       rc, type, ima_canonical_fmt);
724	if (rc < 0) {
725		rc = 0;
726		goto out;
727	}
728
729	rc = ima_write_template_field_data((char *)buffer, rc, DATA_FMT_HEX,
730					   field_data);
731out:
732	kfree(buffer);
733	return rc;
734}
735
736/*
737 *  ima_eventinodexattrnames_init - include a list of xattr names as part of the
738 *  template data
739 */
740int ima_eventinodexattrnames_init(struct ima_event_data *event_data,
741				  struct ima_field_data *field_data)
742{
743	return ima_eventinodexattrs_init_common(event_data, field_data, 'n');
744}
745
746/*
747 *  ima_eventinodexattrlengths_init - include a list of xattr lengths as part of
748 *  the template data
749 */
750int ima_eventinodexattrlengths_init(struct ima_event_data *event_data,
751				    struct ima_field_data *field_data)
752{
753	return ima_eventinodexattrs_init_common(event_data, field_data, 'l');
754}
755
756/*
757 *  ima_eventinodexattrvalues_init - include a list of xattr values as part of
758 *  the template data
759 */
760int ima_eventinodexattrvalues_init(struct ima_event_data *event_data,
761				   struct ima_field_data *field_data)
762{
763	return ima_eventinodexattrs_init_common(event_data, field_data, 'v');
764}