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22#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23
24#include <linux/module.h>
25#include <linux/rculist.h>
26#include <linux/slab.h>
27#include "ima.h"
28
29#define AUDIT_CAUSE_LEN_MAX 32
30
31LIST_HEAD(ima_measurements);
32#ifdef CONFIG_IMA_KEXEC
33static unsigned long binary_runtime_size;
34#else
35static unsigned long binary_runtime_size = ULONG_MAX;
36#endif
37
38
39struct ima_h_table ima_htable = {
40 .len = ATOMIC_LONG_INIT(0),
41 .violations = ATOMIC_LONG_INIT(0),
42 .queue[0 ... IMA_MEASURE_HTABLE_SIZE - 1] = HLIST_HEAD_INIT
43};
44
45
46
47
48
49static DEFINE_MUTEX(ima_extend_list_mutex);
50
51
52static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value,
53 int pcr)
54{
55 struct ima_queue_entry *qe, *ret = NULL;
56 unsigned int key;
57 int rc;
58
59 key = ima_hash_key(digest_value);
60 rcu_read_lock();
61 hlist_for_each_entry_rcu(qe, &ima_htable.queue[key], hnext) {
62 rc = memcmp(qe->entry->digest, digest_value, TPM_DIGEST_SIZE);
63 if ((rc == 0) && (qe->entry->pcr == pcr)) {
64 ret = qe;
65 break;
66 }
67 }
68 rcu_read_unlock();
69 return ret;
70}
71
72
73
74
75
76
77static int get_binary_runtime_size(struct ima_template_entry *entry)
78{
79 int size = 0;
80
81 size += sizeof(u32);
82 size += sizeof(entry->digest);
83 size += sizeof(int);
84 size += strlen(entry->template_desc->name);
85 size += sizeof(entry->template_data_len);
86 size += entry->template_data_len;
87 return size;
88}
89
90
91
92
93
94
95
96static int ima_add_digest_entry(struct ima_template_entry *entry,
97 bool update_htable)
98{
99 struct ima_queue_entry *qe;
100 unsigned int key;
101
102 qe = kmalloc(sizeof(*qe), GFP_KERNEL);
103 if (qe == NULL) {
104 pr_err("OUT OF MEMORY ERROR creating queue entry\n");
105 return -ENOMEM;
106 }
107 qe->entry = entry;
108
109 INIT_LIST_HEAD(&qe->later);
110 list_add_tail_rcu(&qe->later, &ima_measurements);
111
112 atomic_long_inc(&ima_htable.len);
113 if (update_htable) {
114 key = ima_hash_key(entry->digest);
115 hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]);
116 }
117
118 if (binary_runtime_size != ULONG_MAX) {
119 int size;
120
121 size = get_binary_runtime_size(entry);
122 binary_runtime_size = (binary_runtime_size < ULONG_MAX - size) ?
123 binary_runtime_size + size : ULONG_MAX;
124 }
125 return 0;
126}
127
128
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130
131
132
133unsigned long ima_get_binary_runtime_size(void)
134{
135 if (binary_runtime_size >= (ULONG_MAX - sizeof(struct ima_kexec_hdr)))
136 return ULONG_MAX;
137 else
138 return binary_runtime_size + sizeof(struct ima_kexec_hdr);
139};
140
141static int ima_pcr_extend(const u8 *hash, int pcr)
142{
143 int result = 0;
144
145 if (!ima_used_chip)
146 return result;
147
148 result = tpm_pcr_extend(TPM_ANY_NUM, pcr, hash);
149 if (result != 0)
150 pr_err("Error Communicating to TPM chip, result: %d\n", result);
151 return result;
152}
153
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160
161
162int ima_add_template_entry(struct ima_template_entry *entry, int violation,
163 const char *op, struct inode *inode,
164 const unsigned char *filename)
165{
166 u8 digest[TPM_DIGEST_SIZE];
167 const char *audit_cause = "hash_added";
168 char tpm_audit_cause[AUDIT_CAUSE_LEN_MAX];
169 int audit_info = 1;
170 int result = 0, tpmresult = 0;
171
172 mutex_lock(&ima_extend_list_mutex);
173 if (!violation) {
174 memcpy(digest, entry->digest, sizeof(digest));
175 if (ima_lookup_digest_entry(digest, entry->pcr)) {
176 audit_cause = "hash_exists";
177 result = -EEXIST;
178 goto out;
179 }
180 }
181
182 result = ima_add_digest_entry(entry, 1);
183 if (result < 0) {
184 audit_cause = "ENOMEM";
185 audit_info = 0;
186 goto out;
187 }
188
189 if (violation)
190 memset(digest, 0xff, sizeof(digest));
191
192 tpmresult = ima_pcr_extend(digest, entry->pcr);
193 if (tpmresult != 0) {
194 snprintf(tpm_audit_cause, AUDIT_CAUSE_LEN_MAX, "TPM_error(%d)",
195 tpmresult);
196 audit_cause = tpm_audit_cause;
197 audit_info = 0;
198 }
199out:
200 mutex_unlock(&ima_extend_list_mutex);
201 integrity_audit_msg(AUDIT_INTEGRITY_PCR, inode, filename,
202 op, audit_cause, result, audit_info);
203 return result;
204}
205
206int ima_restore_measurement_entry(struct ima_template_entry *entry)
207{
208 int result = 0;
209
210 mutex_lock(&ima_extend_list_mutex);
211 result = ima_add_digest_entry(entry, 0);
212 mutex_unlock(&ima_extend_list_mutex);
213 return result;
214}
215