1b886d83cSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
23323eec9SMimi Zohar /*
33323eec9SMimi Zohar * Copyright (C) 2005,2006,2007,2008 IBM Corporation
43323eec9SMimi Zohar *
53323eec9SMimi Zohar * Authors:
63323eec9SMimi Zohar * Serge Hallyn <serue@us.ibm.com>
73323eec9SMimi Zohar * Reiner Sailer <sailer@watson.ibm.com>
83323eec9SMimi Zohar * Mimi Zohar <zohar@us.ibm.com>
93323eec9SMimi Zohar *
103323eec9SMimi Zohar * File: ima_queue.c
113323eec9SMimi Zohar * Implements queues that store template measurements and
123323eec9SMimi Zohar * maintains aggregate over the stored measurements
133323eec9SMimi Zohar * in the pre-configured TPM PCR (if available).
143323eec9SMimi Zohar * The measurement list is append-only. No entry is
153323eec9SMimi Zohar * ever removed or changed during the boot-cycle.
163323eec9SMimi Zohar */
1720ee451fSJoe Perches
183323eec9SMimi Zohar #include <linux/rculist.h>
195a0e3ad6STejun Heo #include <linux/slab.h>
203323eec9SMimi Zohar #include "ima.h"
213323eec9SMimi Zohar
227b7e5916SRoberto Sassu #define AUDIT_CAUSE_LEN_MAX 32
237b7e5916SRoberto Sassu
240b6cf6b9SRoberto Sassu /* pre-allocated array of tpm_digest structures to extend a PCR */
250b6cf6b9SRoberto Sassu static struct tpm_digest *digests;
260b6cf6b9SRoberto Sassu
273323eec9SMimi Zohar LIST_HEAD(ima_measurements); /* list of all measurements */
28d158847aSMimi Zohar #ifdef CONFIG_IMA_KEXEC
29d158847aSMimi Zohar static unsigned long binary_runtime_size;
30d158847aSMimi Zohar #else
31d158847aSMimi Zohar static unsigned long binary_runtime_size = ULONG_MAX;
32d158847aSMimi Zohar #endif
333323eec9SMimi Zohar
343323eec9SMimi Zohar /* key: inode (before secure-hashing a file) */
353323eec9SMimi Zohar struct ima_h_table ima_htable = {
363323eec9SMimi Zohar .len = ATOMIC_LONG_INIT(0),
373323eec9SMimi Zohar .violations = ATOMIC_LONG_INIT(0),
383323eec9SMimi Zohar .queue[0 ... IMA_MEASURE_HTABLE_SIZE - 1] = HLIST_HEAD_INIT
393323eec9SMimi Zohar };
403323eec9SMimi Zohar
413323eec9SMimi Zohar /* mutex protects atomicity of extending measurement list
423323eec9SMimi Zohar * and extending the TPM PCR aggregate. Since tpm_extend can take
433323eec9SMimi Zohar * long (and the tpm driver uses a mutex), we can't use the spinlock.
443323eec9SMimi Zohar */
453323eec9SMimi Zohar static DEFINE_MUTEX(ima_extend_list_mutex);
463323eec9SMimi Zohar
473323eec9SMimi Zohar /* lookup up the digest value in the hash table, and return the entry */
ima_lookup_digest_entry(u8 * digest_value,int pcr)4867696f6dSEric Richter static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value,
4967696f6dSEric Richter int pcr)
503323eec9SMimi Zohar {
513323eec9SMimi Zohar struct ima_queue_entry *qe, *ret = NULL;
523323eec9SMimi Zohar unsigned int key;
533323eec9SMimi Zohar int rc;
543323eec9SMimi Zohar
553323eec9SMimi Zohar key = ima_hash_key(digest_value);
563323eec9SMimi Zohar rcu_read_lock();
57b67bfe0dSSasha Levin hlist_for_each_entry_rcu(qe, &ima_htable.queue[key], hnext) {
582592677cSRoberto Sassu rc = memcmp(qe->entry->digests[ima_hash_algo_idx].digest,
592592677cSRoberto Sassu digest_value, hash_digest_size[ima_hash_algo]);
6067696f6dSEric Richter if ((rc == 0) && (qe->entry->pcr == pcr)) {
613323eec9SMimi Zohar ret = qe;
623323eec9SMimi Zohar break;
633323eec9SMimi Zohar }
643323eec9SMimi Zohar }
653323eec9SMimi Zohar rcu_read_unlock();
663323eec9SMimi Zohar return ret;
673323eec9SMimi Zohar }
683323eec9SMimi Zohar
69d158847aSMimi Zohar /*
70d158847aSMimi Zohar * Calculate the memory required for serializing a single
71d158847aSMimi Zohar * binary_runtime_measurement list entry, which contains a
72d158847aSMimi Zohar * couple of variable length fields (e.g template name and data).
73d158847aSMimi Zohar */
get_binary_runtime_size(struct ima_template_entry * entry)74d158847aSMimi Zohar static int get_binary_runtime_size(struct ima_template_entry *entry)
75d158847aSMimi Zohar {
76d158847aSMimi Zohar int size = 0;
77d158847aSMimi Zohar
78d158847aSMimi Zohar size += sizeof(u32); /* pcr */
79aa724fe1SRoberto Sassu size += TPM_DIGEST_SIZE;
80d158847aSMimi Zohar size += sizeof(int); /* template name size field */
81e4586c79SRoberto Sassu size += strlen(entry->template_desc->name);
82d158847aSMimi Zohar size += sizeof(entry->template_data_len);
83d158847aSMimi Zohar size += entry->template_data_len;
84d158847aSMimi Zohar return size;
85d158847aSMimi Zohar }
86d158847aSMimi Zohar
873323eec9SMimi Zohar /* ima_add_template_entry helper function:
88dcfc5693SMimi Zohar * - Add template entry to the measurement list and hash table, for
89dcfc5693SMimi Zohar * all entries except those carried across kexec.
903323eec9SMimi Zohar *
913323eec9SMimi Zohar * (Called with ima_extend_list_mutex held.)
923323eec9SMimi Zohar */
ima_add_digest_entry(struct ima_template_entry * entry,bool update_htable)93dcfc5693SMimi Zohar static int ima_add_digest_entry(struct ima_template_entry *entry,
94dcfc5693SMimi Zohar bool update_htable)
953323eec9SMimi Zohar {
963323eec9SMimi Zohar struct ima_queue_entry *qe;
973323eec9SMimi Zohar unsigned int key;
983323eec9SMimi Zohar
993323eec9SMimi Zohar qe = kmalloc(sizeof(*qe), GFP_KERNEL);
1003323eec9SMimi Zohar if (qe == NULL) {
10120ee451fSJoe Perches pr_err("OUT OF MEMORY ERROR creating queue entry\n");
1023323eec9SMimi Zohar return -ENOMEM;
1033323eec9SMimi Zohar }
1043323eec9SMimi Zohar qe->entry = entry;
1053323eec9SMimi Zohar
1063323eec9SMimi Zohar INIT_LIST_HEAD(&qe->later);
1073323eec9SMimi Zohar list_add_tail_rcu(&qe->later, &ima_measurements);
1083323eec9SMimi Zohar
1093323eec9SMimi Zohar atomic_long_inc(&ima_htable.len);
110dcfc5693SMimi Zohar if (update_htable) {
1112592677cSRoberto Sassu key = ima_hash_key(entry->digests[ima_hash_algo_idx].digest);
1123323eec9SMimi Zohar hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]);
113dcfc5693SMimi Zohar }
114d158847aSMimi Zohar
115d158847aSMimi Zohar if (binary_runtime_size != ULONG_MAX) {
116d158847aSMimi Zohar int size;
117d158847aSMimi Zohar
118d158847aSMimi Zohar size = get_binary_runtime_size(entry);
119d158847aSMimi Zohar binary_runtime_size = (binary_runtime_size < ULONG_MAX - size) ?
120d158847aSMimi Zohar binary_runtime_size + size : ULONG_MAX;
121d158847aSMimi Zohar }
1223323eec9SMimi Zohar return 0;
1233323eec9SMimi Zohar }
1243323eec9SMimi Zohar
125d158847aSMimi Zohar /*
126d158847aSMimi Zohar * Return the amount of memory required for serializing the
127d158847aSMimi Zohar * entire binary_runtime_measurement list, including the ima_kexec_hdr
128d158847aSMimi Zohar * structure.
129d158847aSMimi Zohar */
ima_get_binary_runtime_size(void)130d158847aSMimi Zohar unsigned long ima_get_binary_runtime_size(void)
131d158847aSMimi Zohar {
132d158847aSMimi Zohar if (binary_runtime_size >= (ULONG_MAX - sizeof(struct ima_kexec_hdr)))
133d158847aSMimi Zohar return ULONG_MAX;
134d158847aSMimi Zohar else
135d158847aSMimi Zohar return binary_runtime_size + sizeof(struct ima_kexec_hdr);
1364be92db3SRoberto Sassu }
137d158847aSMimi Zohar
ima_pcr_extend(struct tpm_digest * digests_arg,int pcr)1381ea973dfSRoberto Sassu static int ima_pcr_extend(struct tpm_digest *digests_arg, int pcr)
1393323eec9SMimi Zohar {
1403323eec9SMimi Zohar int result = 0;
1413323eec9SMimi Zohar
142ec403d8eSStefan Berger if (!ima_tpm_chip)
1433323eec9SMimi Zohar return result;
1443323eec9SMimi Zohar
1451ea973dfSRoberto Sassu result = tpm_pcr_extend(ima_tpm_chip, pcr, digests_arg);
1463323eec9SMimi Zohar if (result != 0)
14720ee451fSJoe Perches pr_err("Error Communicating to TPM chip, result: %d\n", result);
1483323eec9SMimi Zohar return result;
1493323eec9SMimi Zohar }
1503323eec9SMimi Zohar
151d158847aSMimi Zohar /*
152d158847aSMimi Zohar * Add template entry to the measurement list and hash table, and
153d158847aSMimi Zohar * extend the pcr.
154d158847aSMimi Zohar *
155d158847aSMimi Zohar * On systems which support carrying the IMA measurement list across
156d158847aSMimi Zohar * kexec, maintain the total memory size required for serializing the
157d158847aSMimi Zohar * binary_runtime_measurements.
1583323eec9SMimi Zohar */
ima_add_template_entry(struct ima_template_entry * entry,int violation,const char * op,struct inode * inode,const unsigned char * filename)1593323eec9SMimi Zohar int ima_add_template_entry(struct ima_template_entry *entry, int violation,
1609803d413SRoberto Sassu const char *op, struct inode *inode,
1619803d413SRoberto Sassu const unsigned char *filename)
1623323eec9SMimi Zohar {
1632592677cSRoberto Sassu u8 *digest = entry->digests[ima_hash_algo_idx].digest;
1641ea973dfSRoberto Sassu struct tpm_digest *digests_arg = entry->digests;
1653323eec9SMimi Zohar const char *audit_cause = "hash_added";
1667b7e5916SRoberto Sassu char tpm_audit_cause[AUDIT_CAUSE_LEN_MAX];
1673323eec9SMimi Zohar int audit_info = 1;
1687b7e5916SRoberto Sassu int result = 0, tpmresult = 0;
1693323eec9SMimi Zohar
1703323eec9SMimi Zohar mutex_lock(&ima_extend_list_mutex);
171*52c20839STushar Sugandhi if (!violation && !IS_ENABLED(CONFIG_IMA_DISABLE_HTABLE)) {
17267696f6dSEric Richter if (ima_lookup_digest_entry(digest, entry->pcr)) {
1733323eec9SMimi Zohar audit_cause = "hash_exists";
17445fae749SRoberto Sassu result = -EEXIST;
1753323eec9SMimi Zohar goto out;
1763323eec9SMimi Zohar }
1773323eec9SMimi Zohar }
1783323eec9SMimi Zohar
179*52c20839STushar Sugandhi result = ima_add_digest_entry(entry,
180*52c20839STushar Sugandhi !IS_ENABLED(CONFIG_IMA_DISABLE_HTABLE));
1813323eec9SMimi Zohar if (result < 0) {
1823323eec9SMimi Zohar audit_cause = "ENOMEM";
1833323eec9SMimi Zohar audit_info = 0;
1843323eec9SMimi Zohar goto out;
1853323eec9SMimi Zohar }
1863323eec9SMimi Zohar
1873323eec9SMimi Zohar if (violation) /* invalidate pcr */
1881ea973dfSRoberto Sassu digests_arg = digests;
1893323eec9SMimi Zohar
1901ea973dfSRoberto Sassu tpmresult = ima_pcr_extend(digests_arg, entry->pcr);
1917b7e5916SRoberto Sassu if (tpmresult != 0) {
1927b7e5916SRoberto Sassu snprintf(tpm_audit_cause, AUDIT_CAUSE_LEN_MAX, "TPM_error(%d)",
1937b7e5916SRoberto Sassu tpmresult);
1947b7e5916SRoberto Sassu audit_cause = tpm_audit_cause;
1953323eec9SMimi Zohar audit_info = 0;
1963323eec9SMimi Zohar }
1973323eec9SMimi Zohar out:
1983323eec9SMimi Zohar mutex_unlock(&ima_extend_list_mutex);
1999803d413SRoberto Sassu integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
2003323eec9SMimi Zohar op, audit_cause, result, audit_info);
2013323eec9SMimi Zohar return result;
2023323eec9SMimi Zohar }
20394c3aac5SMimi Zohar
ima_restore_measurement_entry(struct ima_template_entry * entry)20494c3aac5SMimi Zohar int ima_restore_measurement_entry(struct ima_template_entry *entry)
20594c3aac5SMimi Zohar {
20694c3aac5SMimi Zohar int result = 0;
20794c3aac5SMimi Zohar
20894c3aac5SMimi Zohar mutex_lock(&ima_extend_list_mutex);
209dcfc5693SMimi Zohar result = ima_add_digest_entry(entry, 0);
21094c3aac5SMimi Zohar mutex_unlock(&ima_extend_list_mutex);
21194c3aac5SMimi Zohar return result;
21294c3aac5SMimi Zohar }
2130b6cf6b9SRoberto Sassu
ima_init_digests(void)2140b6cf6b9SRoberto Sassu int __init ima_init_digests(void)
2150b6cf6b9SRoberto Sassu {
2161ea973dfSRoberto Sassu u16 digest_size;
2171ea973dfSRoberto Sassu u16 crypto_id;
2180b6cf6b9SRoberto Sassu int i;
2190b6cf6b9SRoberto Sassu
2200b6cf6b9SRoberto Sassu if (!ima_tpm_chip)
2210b6cf6b9SRoberto Sassu return 0;
2220b6cf6b9SRoberto Sassu
2230b6cf6b9SRoberto Sassu digests = kcalloc(ima_tpm_chip->nr_allocated_banks, sizeof(*digests),
2240b6cf6b9SRoberto Sassu GFP_NOFS);
2250b6cf6b9SRoberto Sassu if (!digests)
2260b6cf6b9SRoberto Sassu return -ENOMEM;
2270b6cf6b9SRoberto Sassu
2281ea973dfSRoberto Sassu for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++) {
2290b6cf6b9SRoberto Sassu digests[i].alg_id = ima_tpm_chip->allocated_banks[i].alg_id;
2301ea973dfSRoberto Sassu digest_size = ima_tpm_chip->allocated_banks[i].digest_size;
2311ea973dfSRoberto Sassu crypto_id = ima_tpm_chip->allocated_banks[i].crypto_id;
2321ea973dfSRoberto Sassu
2331ea973dfSRoberto Sassu /* for unmapped TPM algorithms digest is still a padded SHA1 */
2341ea973dfSRoberto Sassu if (crypto_id == HASH_ALGO__LAST)
2351ea973dfSRoberto Sassu digest_size = SHA1_DIGEST_SIZE;
2361ea973dfSRoberto Sassu
2371ea973dfSRoberto Sassu memset(digests[i].digest, 0xff, digest_size);
2381ea973dfSRoberto Sassu }
2390b6cf6b9SRoberto Sassu
2400b6cf6b9SRoberto Sassu return 0;
2410b6cf6b9SRoberto Sassu }
242