Thomas Gleixner | b886d83c | 2019-06-01 10:08:55 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 2 | /* |
| 3 | * Copyright (C) 2005,2006,2007,2008 IBM Corporation |
| 4 | * |
| 5 | * Authors: |
| 6 | * Serge Hallyn <serue@us.ibm.com> |
| 7 | * Reiner Sailer <sailer@watson.ibm.com> |
| 8 | * Mimi Zohar <zohar@us.ibm.com> |
| 9 | * |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 10 | * File: ima_queue.c |
| 11 | * Implements queues that store template measurements and |
| 12 | * maintains aggregate over the stored measurements |
| 13 | * in the pre-configured TPM PCR (if available). |
| 14 | * The measurement list is append-only. No entry is |
| 15 | * ever removed or changed during the boot-cycle. |
| 16 | */ |
Joe Perches | 20ee451 | 2014-02-24 13:59:56 -0800 | [diff] [blame] | 17 | |
| 18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 19 | |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 20 | #include <linux/rculist.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 21 | #include <linux/slab.h> |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 22 | #include "ima.h" |
| 23 | |
Roberto Sassu | 7b7e591 | 2011-12-19 15:57:28 +0100 | [diff] [blame] | 24 | #define AUDIT_CAUSE_LEN_MAX 32 |
| 25 | |
Roberto Sassu | 0b6cf6b | 2019-02-06 17:24:52 +0100 | [diff] [blame] | 26 | /* pre-allocated array of tpm_digest structures to extend a PCR */ |
| 27 | static struct tpm_digest *digests; |
| 28 | |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 29 | LIST_HEAD(ima_measurements); /* list of all measurements */ |
Mimi Zohar | d158847 | 2016-12-19 16:22:42 -0800 | [diff] [blame] | 30 | #ifdef CONFIG_IMA_KEXEC |
| 31 | static unsigned long binary_runtime_size; |
| 32 | #else |
| 33 | static unsigned long binary_runtime_size = ULONG_MAX; |
| 34 | #endif |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 35 | |
| 36 | /* key: inode (before secure-hashing a file) */ |
| 37 | struct ima_h_table ima_htable = { |
| 38 | .len = ATOMIC_LONG_INIT(0), |
| 39 | .violations = ATOMIC_LONG_INIT(0), |
| 40 | .queue[0 ... IMA_MEASURE_HTABLE_SIZE - 1] = HLIST_HEAD_INIT |
| 41 | }; |
| 42 | |
| 43 | /* mutex protects atomicity of extending measurement list |
| 44 | * and extending the TPM PCR aggregate. Since tpm_extend can take |
| 45 | * long (and the tpm driver uses a mutex), we can't use the spinlock. |
| 46 | */ |
| 47 | static DEFINE_MUTEX(ima_extend_list_mutex); |
| 48 | |
| 49 | /* lookup up the digest value in the hash table, and return the entry */ |
Eric Richter | 67696f6 | 2016-06-01 13:14:05 -0500 | [diff] [blame] | 50 | static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value, |
| 51 | int pcr) |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 52 | { |
| 53 | struct ima_queue_entry *qe, *ret = NULL; |
| 54 | unsigned int key; |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 55 | int rc; |
| 56 | |
| 57 | key = ima_hash_key(digest_value); |
| 58 | rcu_read_lock(); |
Sasha Levin | b67bfe0 | 2013-02-27 17:06:00 -0800 | [diff] [blame] | 59 | hlist_for_each_entry_rcu(qe, &ima_htable.queue[key], hnext) { |
Mimi Zohar | 140d802 | 2013-03-11 20:29:47 -0400 | [diff] [blame] | 60 | rc = memcmp(qe->entry->digest, digest_value, TPM_DIGEST_SIZE); |
Eric Richter | 67696f6 | 2016-06-01 13:14:05 -0500 | [diff] [blame] | 61 | if ((rc == 0) && (qe->entry->pcr == pcr)) { |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 62 | ret = qe; |
| 63 | break; |
| 64 | } |
| 65 | } |
| 66 | rcu_read_unlock(); |
| 67 | return ret; |
| 68 | } |
| 69 | |
Mimi Zohar | d158847 | 2016-12-19 16:22:42 -0800 | [diff] [blame] | 70 | /* |
| 71 | * Calculate the memory required for serializing a single |
| 72 | * binary_runtime_measurement list entry, which contains a |
| 73 | * couple of variable length fields (e.g template name and data). |
| 74 | */ |
| 75 | static int get_binary_runtime_size(struct ima_template_entry *entry) |
| 76 | { |
| 77 | int size = 0; |
| 78 | |
| 79 | size += sizeof(u32); /* pcr */ |
| 80 | size += sizeof(entry->digest); |
| 81 | size += sizeof(int); /* template name size field */ |
Roberto Sassu | e4586c79 | 2017-05-16 14:53:47 +0200 | [diff] [blame] | 82 | size += strlen(entry->template_desc->name); |
Mimi Zohar | d158847 | 2016-12-19 16:22:42 -0800 | [diff] [blame] | 83 | size += sizeof(entry->template_data_len); |
| 84 | size += entry->template_data_len; |
| 85 | return size; |
| 86 | } |
| 87 | |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 88 | /* ima_add_template_entry helper function: |
Mimi Zohar | dcfc569 | 2016-12-19 16:22:38 -0800 | [diff] [blame] | 89 | * - Add template entry to the measurement list and hash table, for |
| 90 | * all entries except those carried across kexec. |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 91 | * |
| 92 | * (Called with ima_extend_list_mutex held.) |
| 93 | */ |
Mimi Zohar | dcfc569 | 2016-12-19 16:22:38 -0800 | [diff] [blame] | 94 | static int ima_add_digest_entry(struct ima_template_entry *entry, |
| 95 | bool update_htable) |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 96 | { |
| 97 | struct ima_queue_entry *qe; |
| 98 | unsigned int key; |
| 99 | |
| 100 | qe = kmalloc(sizeof(*qe), GFP_KERNEL); |
| 101 | if (qe == NULL) { |
Joe Perches | 20ee451 | 2014-02-24 13:59:56 -0800 | [diff] [blame] | 102 | pr_err("OUT OF MEMORY ERROR creating queue entry\n"); |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 103 | return -ENOMEM; |
| 104 | } |
| 105 | qe->entry = entry; |
| 106 | |
| 107 | INIT_LIST_HEAD(&qe->later); |
| 108 | list_add_tail_rcu(&qe->later, &ima_measurements); |
| 109 | |
| 110 | atomic_long_inc(&ima_htable.len); |
Mimi Zohar | dcfc569 | 2016-12-19 16:22:38 -0800 | [diff] [blame] | 111 | if (update_htable) { |
| 112 | key = ima_hash_key(entry->digest); |
| 113 | hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]); |
| 114 | } |
Mimi Zohar | d158847 | 2016-12-19 16:22:42 -0800 | [diff] [blame] | 115 | |
| 116 | if (binary_runtime_size != ULONG_MAX) { |
| 117 | int size; |
| 118 | |
| 119 | size = get_binary_runtime_size(entry); |
| 120 | binary_runtime_size = (binary_runtime_size < ULONG_MAX - size) ? |
| 121 | binary_runtime_size + size : ULONG_MAX; |
| 122 | } |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 123 | return 0; |
| 124 | } |
| 125 | |
Mimi Zohar | d158847 | 2016-12-19 16:22:42 -0800 | [diff] [blame] | 126 | /* |
| 127 | * Return the amount of memory required for serializing the |
| 128 | * entire binary_runtime_measurement list, including the ima_kexec_hdr |
| 129 | * structure. |
| 130 | */ |
| 131 | unsigned long ima_get_binary_runtime_size(void) |
| 132 | { |
| 133 | if (binary_runtime_size >= (ULONG_MAX - sizeof(struct ima_kexec_hdr))) |
| 134 | return ULONG_MAX; |
| 135 | else |
| 136 | return binary_runtime_size + sizeof(struct ima_kexec_hdr); |
| 137 | }; |
| 138 | |
Eric Richter | 544e1ce | 2016-06-01 13:14:07 -0500 | [diff] [blame] | 139 | static int ima_pcr_extend(const u8 *hash, int pcr) |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 140 | { |
| 141 | int result = 0; |
Roberto Sassu | 0b6cf6b | 2019-02-06 17:24:52 +0100 | [diff] [blame] | 142 | int i; |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 143 | |
Stefan Berger | ec403d8e | 2018-06-26 15:09:33 -0400 | [diff] [blame] | 144 | if (!ima_tpm_chip) |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 145 | return result; |
| 146 | |
Roberto Sassu | 0b6cf6b | 2019-02-06 17:24:52 +0100 | [diff] [blame] | 147 | for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++) |
| 148 | memcpy(digests[i].digest, hash, TPM_DIGEST_SIZE); |
| 149 | |
| 150 | result = tpm_pcr_extend(ima_tpm_chip, pcr, digests); |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 151 | if (result != 0) |
Joe Perches | 20ee451 | 2014-02-24 13:59:56 -0800 | [diff] [blame] | 152 | pr_err("Error Communicating to TPM chip, result: %d\n", result); |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 153 | return result; |
| 154 | } |
| 155 | |
Mimi Zohar | d158847 | 2016-12-19 16:22:42 -0800 | [diff] [blame] | 156 | /* |
| 157 | * Add template entry to the measurement list and hash table, and |
| 158 | * extend the pcr. |
| 159 | * |
| 160 | * On systems which support carrying the IMA measurement list across |
| 161 | * kexec, maintain the total memory size required for serializing the |
| 162 | * binary_runtime_measurements. |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 163 | */ |
| 164 | int ima_add_template_entry(struct ima_template_entry *entry, int violation, |
Roberto Sassu | 9803d41 | 2013-06-07 12:16:27 +0200 | [diff] [blame] | 165 | const char *op, struct inode *inode, |
| 166 | const unsigned char *filename) |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 167 | { |
Mimi Zohar | 140d802 | 2013-03-11 20:29:47 -0400 | [diff] [blame] | 168 | u8 digest[TPM_DIGEST_SIZE]; |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 169 | const char *audit_cause = "hash_added"; |
Roberto Sassu | 7b7e591 | 2011-12-19 15:57:28 +0100 | [diff] [blame] | 170 | char tpm_audit_cause[AUDIT_CAUSE_LEN_MAX]; |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 171 | int audit_info = 1; |
Roberto Sassu | 7b7e591 | 2011-12-19 15:57:28 +0100 | [diff] [blame] | 172 | int result = 0, tpmresult = 0; |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 173 | |
| 174 | mutex_lock(&ima_extend_list_mutex); |
| 175 | if (!violation) { |
Dmitry Kasatkin | 2bb930a | 2014-03-04 18:04:20 +0200 | [diff] [blame] | 176 | memcpy(digest, entry->digest, sizeof(digest)); |
Eric Richter | 67696f6 | 2016-06-01 13:14:05 -0500 | [diff] [blame] | 177 | if (ima_lookup_digest_entry(digest, entry->pcr)) { |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 178 | audit_cause = "hash_exists"; |
Roberto Sassu | 45fae74 | 2011-12-19 15:57:27 +0100 | [diff] [blame] | 179 | result = -EEXIST; |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 180 | goto out; |
| 181 | } |
| 182 | } |
| 183 | |
Mimi Zohar | dcfc569 | 2016-12-19 16:22:38 -0800 | [diff] [blame] | 184 | result = ima_add_digest_entry(entry, 1); |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 185 | if (result < 0) { |
| 186 | audit_cause = "ENOMEM"; |
| 187 | audit_info = 0; |
| 188 | goto out; |
| 189 | } |
| 190 | |
| 191 | if (violation) /* invalidate pcr */ |
Dmitry Kasatkin | 2bb930a | 2014-03-04 18:04:20 +0200 | [diff] [blame] | 192 | memset(digest, 0xff, sizeof(digest)); |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 193 | |
Eric Richter | 544e1ce | 2016-06-01 13:14:07 -0500 | [diff] [blame] | 194 | tpmresult = ima_pcr_extend(digest, entry->pcr); |
Roberto Sassu | 7b7e591 | 2011-12-19 15:57:28 +0100 | [diff] [blame] | 195 | if (tpmresult != 0) { |
| 196 | snprintf(tpm_audit_cause, AUDIT_CAUSE_LEN_MAX, "TPM_error(%d)", |
| 197 | tpmresult); |
| 198 | audit_cause = tpm_audit_cause; |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 199 | audit_info = 0; |
| 200 | } |
| 201 | out: |
| 202 | mutex_unlock(&ima_extend_list_mutex); |
Roberto Sassu | 9803d41 | 2013-06-07 12:16:27 +0200 | [diff] [blame] | 203 | integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename, |
Mimi Zohar | 3323eec | 2009-02-04 09:06:58 -0500 | [diff] [blame] | 204 | op, audit_cause, result, audit_info); |
| 205 | return result; |
| 206 | } |
Mimi Zohar | 94c3aac | 2016-12-19 16:22:35 -0800 | [diff] [blame] | 207 | |
| 208 | int ima_restore_measurement_entry(struct ima_template_entry *entry) |
| 209 | { |
| 210 | int result = 0; |
| 211 | |
| 212 | mutex_lock(&ima_extend_list_mutex); |
Mimi Zohar | dcfc569 | 2016-12-19 16:22:38 -0800 | [diff] [blame] | 213 | result = ima_add_digest_entry(entry, 0); |
Mimi Zohar | 94c3aac | 2016-12-19 16:22:35 -0800 | [diff] [blame] | 214 | mutex_unlock(&ima_extend_list_mutex); |
| 215 | return result; |
| 216 | } |
Roberto Sassu | 0b6cf6b | 2019-02-06 17:24:52 +0100 | [diff] [blame] | 217 | |
| 218 | int __init ima_init_digests(void) |
| 219 | { |
| 220 | int i; |
| 221 | |
| 222 | if (!ima_tpm_chip) |
| 223 | return 0; |
| 224 | |
| 225 | digests = kcalloc(ima_tpm_chip->nr_allocated_banks, sizeof(*digests), |
| 226 | GFP_NOFS); |
| 227 | if (!digests) |
| 228 | return -ENOMEM; |
| 229 | |
| 230 | for (i = 0; i < ima_tpm_chip->nr_allocated_banks; i++) |
| 231 | digests[i].alg_id = ima_tpm_chip->allocated_banks[i].alg_id; |
| 232 | |
| 233 | return 0; |
| 234 | } |