arm/arm64: KVM: Fix BE accesses to GICv2 EISR and ELRSR regs
[linux/fpc-iii.git] / security / integrity / ima / ima_main.c
blob2917f980bf3075c3dacff3531cf03d8e4e39e6f6
1 /*
2 * Copyright (C) 2005,2006,2007,2008 IBM Corporation
4 * Authors:
5 * Reiner Sailer <sailer@watson.ibm.com>
6 * Serge Hallyn <serue@us.ibm.com>
7 * Kylene Hall <kylene@us.ibm.com>
8 * Mimi Zohar <zohar@us.ibm.com>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation, version 2 of the
13 * License.
15 * File: ima_main.c
16 * implements the IMA hooks: ima_bprm_check, ima_file_mmap,
17 * and ima_file_check.
19 #include <linux/module.h>
20 #include <linux/file.h>
21 #include <linux/binfmts.h>
22 #include <linux/mount.h>
23 #include <linux/mman.h>
24 #include <linux/slab.h>
25 #include <linux/xattr.h>
26 #include <linux/ima.h>
27 #include <crypto/hash_info.h>
29 #include "ima.h"
31 int ima_initialized;
33 #ifdef CONFIG_IMA_APPRAISE
34 int ima_appraise = IMA_APPRAISE_ENFORCE;
35 #else
36 int ima_appraise;
37 #endif
39 int ima_hash_algo = HASH_ALGO_SHA1;
40 static int hash_setup_done;
42 static int __init hash_setup(char *str)
44 struct ima_template_desc *template_desc = ima_template_desc_current();
45 int i;
47 if (hash_setup_done)
48 return 1;
50 if (strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) {
51 if (strncmp(str, "sha1", 4) == 0)
52 ima_hash_algo = HASH_ALGO_SHA1;
53 else if (strncmp(str, "md5", 3) == 0)
54 ima_hash_algo = HASH_ALGO_MD5;
55 goto out;
58 for (i = 0; i < HASH_ALGO__LAST; i++) {
59 if (strcmp(str, hash_algo_name[i]) == 0) {
60 ima_hash_algo = i;
61 break;
64 out:
65 hash_setup_done = 1;
66 return 1;
68 __setup("ima_hash=", hash_setup);
71 * ima_rdwr_violation_check
73 * Only invalidate the PCR for measured files:
74 * - Opening a file for write when already open for read,
75 * results in a time of measure, time of use (ToMToU) error.
76 * - Opening a file for read when already open for write,
77 * could result in a file measurement error.
80 static void ima_rdwr_violation_check(struct file *file)
82 struct inode *inode = file_inode(file);
83 fmode_t mode = file->f_mode;
84 bool send_tomtou = false, send_writers = false;
85 char *pathbuf = NULL;
86 const char *pathname;
88 if (!S_ISREG(inode->i_mode) || !ima_initialized)
89 return;
91 if (mode & FMODE_WRITE) {
92 if (atomic_read(&inode->i_readcount) && IS_IMA(inode)) {
93 struct integrity_iint_cache *iint;
94 iint = integrity_iint_find(inode);
95 /* IMA_MEASURE is set from reader side */
96 if (iint && (iint->flags & IMA_MEASURE))
97 send_tomtou = true;
99 } else {
100 if ((atomic_read(&inode->i_writecount) > 0) &&
101 ima_must_measure(inode, MAY_READ, FILE_CHECK))
102 send_writers = true;
105 if (!send_tomtou && !send_writers)
106 return;
108 pathname = ima_d_path(&file->f_path, &pathbuf);
110 if (send_tomtou)
111 ima_add_violation(file, pathname, "invalid_pcr", "ToMToU");
112 if (send_writers)
113 ima_add_violation(file, pathname,
114 "invalid_pcr", "open_writers");
115 kfree(pathbuf);
118 static void ima_check_last_writer(struct integrity_iint_cache *iint,
119 struct inode *inode, struct file *file)
121 fmode_t mode = file->f_mode;
123 if (!(mode & FMODE_WRITE))
124 return;
126 mutex_lock(&inode->i_mutex);
127 if (atomic_read(&inode->i_writecount) == 1 &&
128 iint->version != inode->i_version) {
129 iint->flags &= ~IMA_DONE_MASK;
130 if (iint->flags & IMA_APPRAISE)
131 ima_update_xattr(iint, file);
133 mutex_unlock(&inode->i_mutex);
137 * ima_file_free - called on __fput()
138 * @file: pointer to file structure being freed
140 * Flag files that changed, based on i_version
142 void ima_file_free(struct file *file)
144 struct inode *inode = file_inode(file);
145 struct integrity_iint_cache *iint;
147 if (!iint_initialized || !S_ISREG(inode->i_mode))
148 return;
150 iint = integrity_iint_find(inode);
151 if (!iint)
152 return;
154 ima_check_last_writer(iint, inode, file);
157 static int process_measurement(struct file *file, const char *filename,
158 int mask, int function)
160 struct inode *inode = file_inode(file);
161 struct integrity_iint_cache *iint;
162 struct ima_template_desc *template_desc;
163 char *pathbuf = NULL;
164 const char *pathname = NULL;
165 int rc = -ENOMEM, action, must_appraise, _func;
166 struct evm_ima_xattr_data *xattr_value = NULL, **xattr_ptr = NULL;
167 int xattr_len = 0;
169 if (!ima_initialized || !S_ISREG(inode->i_mode))
170 return 0;
172 /* Return an IMA_MEASURE, IMA_APPRAISE, IMA_AUDIT action
173 * bitmask based on the appraise/audit/measurement policy.
174 * Included is the appraise submask.
176 action = ima_get_action(inode, mask, function);
177 if (!action)
178 return 0;
180 must_appraise = action & IMA_APPRAISE;
182 /* Is the appraise rule hook specific? */
183 _func = (action & IMA_FILE_APPRAISE) ? FILE_CHECK : function;
185 mutex_lock(&inode->i_mutex);
187 iint = integrity_inode_get(inode);
188 if (!iint)
189 goto out;
191 /* Determine if already appraised/measured based on bitmask
192 * (IMA_MEASURE, IMA_MEASURED, IMA_XXXX_APPRAISE, IMA_XXXX_APPRAISED,
193 * IMA_AUDIT, IMA_AUDITED)
195 iint->flags |= action;
196 action &= IMA_DO_MASK;
197 action &= ~((iint->flags & IMA_DONE_MASK) >> 1);
199 /* Nothing to do, just return existing appraised status */
200 if (!action) {
201 if (must_appraise)
202 rc = ima_get_cache_status(iint, _func);
203 goto out_digsig;
206 template_desc = ima_template_desc_current();
207 if (strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) == 0) {
208 if (action & IMA_APPRAISE_SUBMASK)
209 xattr_ptr = &xattr_value;
210 } else
211 xattr_ptr = &xattr_value;
213 rc = ima_collect_measurement(iint, file, xattr_ptr, &xattr_len);
214 if (rc != 0) {
215 if (file->f_flags & O_DIRECT)
216 rc = (iint->flags & IMA_PERMIT_DIRECTIO) ? 0 : -EACCES;
217 goto out_digsig;
220 pathname = filename ?: ima_d_path(&file->f_path, &pathbuf);
222 if (action & IMA_MEASURE)
223 ima_store_measurement(iint, file, pathname,
224 xattr_value, xattr_len);
225 if (action & IMA_APPRAISE_SUBMASK)
226 rc = ima_appraise_measurement(_func, iint, file, pathname,
227 xattr_value, xattr_len);
228 if (action & IMA_AUDIT)
229 ima_audit_measurement(iint, pathname);
230 kfree(pathbuf);
231 out_digsig:
232 if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG))
233 rc = -EACCES;
234 out:
235 mutex_unlock(&inode->i_mutex);
236 kfree(xattr_value);
237 if ((rc && must_appraise) && (ima_appraise & IMA_APPRAISE_ENFORCE))
238 return -EACCES;
239 return 0;
243 * ima_file_mmap - based on policy, collect/store measurement.
244 * @file: pointer to the file to be measured (May be NULL)
245 * @prot: contains the protection that will be applied by the kernel.
247 * Measure files being mmapped executable based on the ima_must_measure()
248 * policy decision.
250 * On success return 0. On integrity appraisal error, assuming the file
251 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
253 int ima_file_mmap(struct file *file, unsigned long prot)
255 if (file && (prot & PROT_EXEC))
256 return process_measurement(file, NULL, MAY_EXEC, MMAP_CHECK);
257 return 0;
261 * ima_bprm_check - based on policy, collect/store measurement.
262 * @bprm: contains the linux_binprm structure
264 * The OS protects against an executable file, already open for write,
265 * from being executed in deny_write_access() and an executable file,
266 * already open for execute, from being modified in get_write_access().
267 * So we can be certain that what we verify and measure here is actually
268 * what is being executed.
270 * On success return 0. On integrity appraisal error, assuming the file
271 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
273 int ima_bprm_check(struct linux_binprm *bprm)
275 return process_measurement(bprm->file,
276 (strcmp(bprm->filename, bprm->interp) == 0) ?
277 bprm->filename : bprm->interp,
278 MAY_EXEC, BPRM_CHECK);
282 * ima_path_check - based on policy, collect/store measurement.
283 * @file: pointer to the file to be measured
284 * @mask: contains MAY_READ, MAY_WRITE or MAY_EXECUTE
286 * Measure files based on the ima_must_measure() policy decision.
288 * On success return 0. On integrity appraisal error, assuming the file
289 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
291 int ima_file_check(struct file *file, int mask)
293 ima_rdwr_violation_check(file);
294 return process_measurement(file, NULL,
295 mask & (MAY_READ | MAY_WRITE | MAY_EXEC),
296 FILE_CHECK);
298 EXPORT_SYMBOL_GPL(ima_file_check);
301 * ima_module_check - based on policy, collect/store/appraise measurement.
302 * @file: pointer to the file to be measured/appraised
304 * Measure/appraise kernel modules based on policy.
306 * On success return 0. On integrity appraisal error, assuming the file
307 * is in policy and IMA-appraisal is in enforcing mode, return -EACCES.
309 int ima_module_check(struct file *file)
311 if (!file) {
312 #ifndef CONFIG_MODULE_SIG_FORCE
313 if ((ima_appraise & IMA_APPRAISE_MODULES) &&
314 (ima_appraise & IMA_APPRAISE_ENFORCE))
315 return -EACCES; /* INTEGRITY_UNKNOWN */
316 #endif
317 return 0; /* We rely on module signature checking */
319 return process_measurement(file, NULL, MAY_EXEC, MODULE_CHECK);
322 int ima_fw_from_file(struct file *file, char *buf, size_t size)
324 if (!file) {
325 if ((ima_appraise & IMA_APPRAISE_FIRMWARE) &&
326 (ima_appraise & IMA_APPRAISE_ENFORCE))
327 return -EACCES; /* INTEGRITY_UNKNOWN */
328 return 0;
330 return process_measurement(file, NULL, MAY_EXEC, FIRMWARE_CHECK);
333 static int __init init_ima(void)
335 int error;
337 hash_setup(CONFIG_IMA_DEFAULT_HASH);
338 error = ima_init();
339 if (error)
340 goto out;
342 error = ima_init_keyring(INTEGRITY_KEYRING_IMA);
343 if (error)
344 goto out;
345 ima_initialized = 1;
346 out:
347 return error;
350 late_initcall(init_ima); /* Start IMA after the TPM is available */
352 MODULE_DESCRIPTION("Integrity Measurement Architecture");
353 MODULE_LICENSE("GPL");