1 /* Updated: Karl MacMillan <kmacmillan@tresys.com>
2 *
3 * Added conditional policy language extensions
4 *
5 * Updated: Hewlett-Packard <paul@paul-moore.com>
6 *
7 * Added support for the policy capability bitmap
8 *
9 * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
10 * Copyright (C) 2003 - 2004 Tresys Technology, LLC
11 * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation, version 2.
15 */
16
17 #include <linux/kernel.h>
18 #include <linux/pagemap.h>
19 #include <linux/slab.h>
20 #include <linux/vmalloc.h>
21 #include <linux/fs.h>
22 #include <linux/mutex.h>
23 #include <linux/init.h>
24 #include <linux/string.h>
25 #include <linux/security.h>
26 #include <linux/major.h>
27 #include <linux/seq_file.h>
28 #include <linux/percpu.h>
29 #include <linux/audit.h>
30 #include <linux/uaccess.h>
31 #include <linux/kobject.h>
32 #include <linux/ctype.h>
33
34 /* selinuxfs pseudo filesystem for exporting the security policy API.
35 Based on the proc code and the fs/nfsd/nfsctl.c code. */
36
37 #include "flask.h"
38 #include "avc.h"
39 #include "avc_ss.h"
40 #include "security.h"
41 #include "objsec.h"
42 #include "conditional.h"
43
44 /* Policy capability filenames */
45 static char *policycap_names[] = {
46 "network_peer_controls",
47 "open_perms"
48 };
49
50 unsigned int selinux_checkreqprot = CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE;
51
checkreqprot_setup(char * str)52 static int __init checkreqprot_setup(char *str)
53 {
54 unsigned long checkreqprot;
55 if (!strict_strtoul(str, 0, &checkreqprot))
56 selinux_checkreqprot = checkreqprot ? 1 : 0;
57 return 1;
58 }
59 __setup("checkreqprot=", checkreqprot_setup);
60
61 static DEFINE_MUTEX(sel_mutex);
62
63 /* global data for booleans */
64 static struct dentry *bool_dir;
65 static int bool_num;
66 static char **bool_pending_names;
67 static int *bool_pending_values;
68
69 /* global data for classes */
70 static struct dentry *class_dir;
71 static unsigned long last_class_ino;
72
73 static char policy_opened;
74
75 /* global data for policy capabilities */
76 static struct dentry *policycap_dir;
77
78 /* Check whether a task is allowed to use a security operation. */
task_has_security(struct task_struct * tsk,u32 perms)79 static int task_has_security(struct task_struct *tsk,
80 u32 perms)
81 {
82 const struct task_security_struct *tsec;
83 u32 sid = 0;
84
85 rcu_read_lock();
86 tsec = __task_cred(tsk)->security;
87 if (tsec)
88 sid = tsec->sid;
89 rcu_read_unlock();
90 if (!tsec)
91 return -EACCES;
92
93 return avc_has_perm(sid, SECINITSID_SECURITY,
94 SECCLASS_SECURITY, perms, NULL);
95 }
96
97 enum sel_inos {
98 SEL_ROOT_INO = 2,
99 SEL_LOAD, /* load policy */
100 SEL_ENFORCE, /* get or set enforcing status */
101 SEL_CONTEXT, /* validate context */
102 SEL_ACCESS, /* compute access decision */
103 SEL_CREATE, /* compute create labeling decision */
104 SEL_RELABEL, /* compute relabeling decision */
105 SEL_USER, /* compute reachable user contexts */
106 SEL_POLICYVERS, /* return policy version for this kernel */
107 SEL_COMMIT_BOOLS, /* commit new boolean values */
108 SEL_MLS, /* return if MLS policy is enabled */
109 SEL_DISABLE, /* disable SELinux until next reboot */
110 SEL_MEMBER, /* compute polyinstantiation membership decision */
111 SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
112 SEL_COMPAT_NET, /* whether to use old compat network packet controls */
113 SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
114 SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
115 SEL_STATUS, /* export current status using mmap() */
116 SEL_POLICY, /* allow userspace to read the in kernel policy */
117 SEL_INO_NEXT, /* The next inode number to use */
118 };
119
120 static unsigned long sel_last_ino = SEL_INO_NEXT - 1;
121
122 #define SEL_INITCON_INO_OFFSET 0x01000000
123 #define SEL_BOOL_INO_OFFSET 0x02000000
124 #define SEL_CLASS_INO_OFFSET 0x04000000
125 #define SEL_POLICYCAP_INO_OFFSET 0x08000000
126 #define SEL_INO_MASK 0x00ffffff
127
128 #define TMPBUFLEN 12
sel_read_enforce(struct file * filp,char __user * buf,size_t count,loff_t * ppos)129 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
130 size_t count, loff_t *ppos)
131 {
132 char tmpbuf[TMPBUFLEN];
133 ssize_t length;
134
135 length = scnprintf(tmpbuf, TMPBUFLEN, "%d", selinux_enforcing);
136 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
137 }
138
139 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
sel_write_enforce(struct file * file,const char __user * buf,size_t count,loff_t * ppos)140 static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
141 size_t count, loff_t *ppos)
142
143 {
144 char *page = NULL;
145 ssize_t length;
146 int new_value;
147
148 length = -ENOMEM;
149 if (count >= PAGE_SIZE)
150 goto out;
151
152 /* No partial writes. */
153 length = EINVAL;
154 if (*ppos != 0)
155 goto out;
156
157 length = -ENOMEM;
158 page = (char *)get_zeroed_page(GFP_KERNEL);
159 if (!page)
160 goto out;
161
162 length = -EFAULT;
163 if (copy_from_user(page, buf, count))
164 goto out;
165
166 length = -EINVAL;
167 if (sscanf(page, "%d", &new_value) != 1)
168 goto out;
169
170 if (new_value != selinux_enforcing) {
171 length = task_has_security(current, SECURITY__SETENFORCE);
172 if (length)
173 goto out;
174 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
175 "enforcing=%d old_enforcing=%d auid=%u ses=%u",
176 new_value, selinux_enforcing,
177 from_kuid(&init_user_ns, audit_get_loginuid(current)),
178 audit_get_sessionid(current));
179 selinux_enforcing = new_value;
180 if (selinux_enforcing)
181 avc_ss_reset(0);
182 selnl_notify_setenforce(selinux_enforcing);
183 selinux_status_update_setenforce(selinux_enforcing);
184 }
185 length = count;
186 out:
187 free_page((unsigned long) page);
188 return length;
189 }
190 #else
191 #define sel_write_enforce NULL
192 #endif
193
194 static const struct file_operations sel_enforce_ops = {
195 .read = sel_read_enforce,
196 .write = sel_write_enforce,
197 .llseek = generic_file_llseek,
198 };
199
sel_read_handle_unknown(struct file * filp,char __user * buf,size_t count,loff_t * ppos)200 static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
201 size_t count, loff_t *ppos)
202 {
203 char tmpbuf[TMPBUFLEN];
204 ssize_t length;
205 ino_t ino = file_inode(filp)->i_ino;
206 int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
207 security_get_reject_unknown() : !security_get_allow_unknown();
208
209 length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
210 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
211 }
212
213 static const struct file_operations sel_handle_unknown_ops = {
214 .read = sel_read_handle_unknown,
215 .llseek = generic_file_llseek,
216 };
217
sel_open_handle_status(struct inode * inode,struct file * filp)218 static int sel_open_handle_status(struct inode *inode, struct file *filp)
219 {
220 struct page *status = selinux_kernel_status_page();
221
222 if (!status)
223 return -ENOMEM;
224
225 filp->private_data = status;
226
227 return 0;
228 }
229
sel_read_handle_status(struct file * filp,char __user * buf,size_t count,loff_t * ppos)230 static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
231 size_t count, loff_t *ppos)
232 {
233 struct page *status = filp->private_data;
234
235 BUG_ON(!status);
236
237 return simple_read_from_buffer(buf, count, ppos,
238 page_address(status),
239 sizeof(struct selinux_kernel_status));
240 }
241
sel_mmap_handle_status(struct file * filp,struct vm_area_struct * vma)242 static int sel_mmap_handle_status(struct file *filp,
243 struct vm_area_struct *vma)
244 {
245 struct page *status = filp->private_data;
246 unsigned long size = vma->vm_end - vma->vm_start;
247
248 BUG_ON(!status);
249
250 /* only allows one page from the head */
251 if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
252 return -EIO;
253 /* disallow writable mapping */
254 if (vma->vm_flags & VM_WRITE)
255 return -EPERM;
256 /* disallow mprotect() turns it into writable */
257 vma->vm_flags &= ~VM_MAYWRITE;
258
259 return remap_pfn_range(vma, vma->vm_start,
260 page_to_pfn(status),
261 size, vma->vm_page_prot);
262 }
263
264 static const struct file_operations sel_handle_status_ops = {
265 .open = sel_open_handle_status,
266 .read = sel_read_handle_status,
267 .mmap = sel_mmap_handle_status,
268 .llseek = generic_file_llseek,
269 };
270
271 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
sel_write_disable(struct file * file,const char __user * buf,size_t count,loff_t * ppos)272 static ssize_t sel_write_disable(struct file *file, const char __user *buf,
273 size_t count, loff_t *ppos)
274
275 {
276 char *page = NULL;
277 ssize_t length;
278 int new_value;
279
280 length = -ENOMEM;
281 if (count >= PAGE_SIZE)
282 goto out;
283
284 /* No partial writes. */
285 length = -EINVAL;
286 if (*ppos != 0)
287 goto out;
288
289 length = -ENOMEM;
290 page = (char *)get_zeroed_page(GFP_KERNEL);
291 if (!page)
292 goto out;
293
294 length = -EFAULT;
295 if (copy_from_user(page, buf, count))
296 goto out;
297
298 length = -EINVAL;
299 if (sscanf(page, "%d", &new_value) != 1)
300 goto out;
301
302 if (new_value) {
303 length = selinux_disable();
304 if (length)
305 goto out;
306 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_STATUS,
307 "selinux=0 auid=%u ses=%u",
308 from_kuid(&init_user_ns, audit_get_loginuid(current)),
309 audit_get_sessionid(current));
310 }
311
312 length = count;
313 out:
314 free_page((unsigned long) page);
315 return length;
316 }
317 #else
318 #define sel_write_disable NULL
319 #endif
320
321 static const struct file_operations sel_disable_ops = {
322 .write = sel_write_disable,
323 .llseek = generic_file_llseek,
324 };
325
sel_read_policyvers(struct file * filp,char __user * buf,size_t count,loff_t * ppos)326 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
327 size_t count, loff_t *ppos)
328 {
329 char tmpbuf[TMPBUFLEN];
330 ssize_t length;
331
332 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
333 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
334 }
335
336 static const struct file_operations sel_policyvers_ops = {
337 .read = sel_read_policyvers,
338 .llseek = generic_file_llseek,
339 };
340
341 /* declaration for sel_write_load */
342 static int sel_make_bools(void);
343 static int sel_make_classes(void);
344 static int sel_make_policycap(void);
345
346 /* declaration for sel_make_class_dirs */
347 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
348 unsigned long *ino);
349
sel_read_mls(struct file * filp,char __user * buf,size_t count,loff_t * ppos)350 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
351 size_t count, loff_t *ppos)
352 {
353 char tmpbuf[TMPBUFLEN];
354 ssize_t length;
355
356 length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
357 security_mls_enabled());
358 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
359 }
360
361 static const struct file_operations sel_mls_ops = {
362 .read = sel_read_mls,
363 .llseek = generic_file_llseek,
364 };
365
366 struct policy_load_memory {
367 size_t len;
368 void *data;
369 };
370
sel_open_policy(struct inode * inode,struct file * filp)371 static int sel_open_policy(struct inode *inode, struct file *filp)
372 {
373 struct policy_load_memory *plm = NULL;
374 int rc;
375
376 BUG_ON(filp->private_data);
377
378 mutex_lock(&sel_mutex);
379
380 rc = task_has_security(current, SECURITY__READ_POLICY);
381 if (rc)
382 goto err;
383
384 rc = -EBUSY;
385 if (policy_opened)
386 goto err;
387
388 rc = -ENOMEM;
389 plm = kzalloc(sizeof(*plm), GFP_KERNEL);
390 if (!plm)
391 goto err;
392
393 if (i_size_read(inode) != security_policydb_len()) {
394 mutex_lock(&inode->i_mutex);
395 i_size_write(inode, security_policydb_len());
396 mutex_unlock(&inode->i_mutex);
397 }
398
399 rc = security_read_policy(&plm->data, &plm->len);
400 if (rc)
401 goto err;
402
403 policy_opened = 1;
404
405 filp->private_data = plm;
406
407 mutex_unlock(&sel_mutex);
408
409 return 0;
410 err:
411 mutex_unlock(&sel_mutex);
412
413 if (plm)
414 vfree(plm->data);
415 kfree(plm);
416 return rc;
417 }
418
sel_release_policy(struct inode * inode,struct file * filp)419 static int sel_release_policy(struct inode *inode, struct file *filp)
420 {
421 struct policy_load_memory *plm = filp->private_data;
422
423 BUG_ON(!plm);
424
425 policy_opened = 0;
426
427 vfree(plm->data);
428 kfree(plm);
429
430 return 0;
431 }
432
sel_read_policy(struct file * filp,char __user * buf,size_t count,loff_t * ppos)433 static ssize_t sel_read_policy(struct file *filp, char __user *buf,
434 size_t count, loff_t *ppos)
435 {
436 struct policy_load_memory *plm = filp->private_data;
437 int ret;
438
439 mutex_lock(&sel_mutex);
440
441 ret = task_has_security(current, SECURITY__READ_POLICY);
442 if (ret)
443 goto out;
444
445 ret = simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
446 out:
447 mutex_unlock(&sel_mutex);
448 return ret;
449 }
450
sel_mmap_policy_fault(struct vm_area_struct * vma,struct vm_fault * vmf)451 static int sel_mmap_policy_fault(struct vm_area_struct *vma,
452 struct vm_fault *vmf)
453 {
454 struct policy_load_memory *plm = vma->vm_file->private_data;
455 unsigned long offset;
456 struct page *page;
457
458 if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
459 return VM_FAULT_SIGBUS;
460
461 offset = vmf->pgoff << PAGE_SHIFT;
462 if (offset >= roundup(plm->len, PAGE_SIZE))
463 return VM_FAULT_SIGBUS;
464
465 page = vmalloc_to_page(plm->data + offset);
466 get_page(page);
467
468 vmf->page = page;
469
470 return 0;
471 }
472
473 static struct vm_operations_struct sel_mmap_policy_ops = {
474 .fault = sel_mmap_policy_fault,
475 .page_mkwrite = sel_mmap_policy_fault,
476 };
477
sel_mmap_policy(struct file * filp,struct vm_area_struct * vma)478 static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
479 {
480 if (vma->vm_flags & VM_SHARED) {
481 /* do not allow mprotect to make mapping writable */
482 vma->vm_flags &= ~VM_MAYWRITE;
483
484 if (vma->vm_flags & VM_WRITE)
485 return -EACCES;
486 }
487
488 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
489 vma->vm_ops = &sel_mmap_policy_ops;
490
491 return 0;
492 }
493
494 static const struct file_operations sel_policy_ops = {
495 .open = sel_open_policy,
496 .read = sel_read_policy,
497 .mmap = sel_mmap_policy,
498 .release = sel_release_policy,
499 .llseek = generic_file_llseek,
500 };
501
sel_write_load(struct file * file,const char __user * buf,size_t count,loff_t * ppos)502 static ssize_t sel_write_load(struct file *file, const char __user *buf,
503 size_t count, loff_t *ppos)
504
505 {
506 ssize_t length;
507 void *data = NULL;
508
509 mutex_lock(&sel_mutex);
510
511 length = task_has_security(current, SECURITY__LOAD_POLICY);
512 if (length)
513 goto out;
514
515 /* No partial writes. */
516 length = -EINVAL;
517 if (*ppos != 0)
518 goto out;
519
520 length = -EFBIG;
521 if (count > 64 * 1024 * 1024)
522 goto out;
523
524 length = -ENOMEM;
525 data = vmalloc(count);
526 if (!data)
527 goto out;
528
529 length = -EFAULT;
530 if (copy_from_user(data, buf, count) != 0)
531 goto out;
532
533 length = security_load_policy(data, count);
534 if (length)
535 goto out;
536
537 length = sel_make_bools();
538 if (length)
539 goto out1;
540
541 length = sel_make_classes();
542 if (length)
543 goto out1;
544
545 length = sel_make_policycap();
546 if (length)
547 goto out1;
548
549 length = count;
550
551 out1:
552 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
553 "policy loaded auid=%u ses=%u",
554 from_kuid(&init_user_ns, audit_get_loginuid(current)),
555 audit_get_sessionid(current));
556 out:
557 mutex_unlock(&sel_mutex);
558 vfree(data);
559 return length;
560 }
561
562 static const struct file_operations sel_load_ops = {
563 .write = sel_write_load,
564 .llseek = generic_file_llseek,
565 };
566
sel_write_context(struct file * file,char * buf,size_t size)567 static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
568 {
569 char *canon = NULL;
570 u32 sid, len;
571 ssize_t length;
572
573 length = task_has_security(current, SECURITY__CHECK_CONTEXT);
574 if (length)
575 goto out;
576
577 length = security_context_to_sid(buf, size, &sid);
578 if (length)
579 goto out;
580
581 length = security_sid_to_context(sid, &canon, &len);
582 if (length)
583 goto out;
584
585 length = -ERANGE;
586 if (len > SIMPLE_TRANSACTION_LIMIT) {
587 printk(KERN_ERR "SELinux: %s: context size (%u) exceeds "
588 "payload max\n", __func__, len);
589 goto out;
590 }
591
592 memcpy(buf, canon, len);
593 length = len;
594 out:
595 kfree(canon);
596 return length;
597 }
598
sel_read_checkreqprot(struct file * filp,char __user * buf,size_t count,loff_t * ppos)599 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
600 size_t count, loff_t *ppos)
601 {
602 char tmpbuf[TMPBUFLEN];
603 ssize_t length;
604
605 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
606 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
607 }
608
sel_write_checkreqprot(struct file * file,const char __user * buf,size_t count,loff_t * ppos)609 static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
610 size_t count, loff_t *ppos)
611 {
612 char *page = NULL;
613 ssize_t length;
614 unsigned int new_value;
615
616 length = task_has_security(current, SECURITY__SETCHECKREQPROT);
617 if (length)
618 goto out;
619
620 length = -ENOMEM;
621 if (count >= PAGE_SIZE)
622 goto out;
623
624 /* No partial writes. */
625 length = -EINVAL;
626 if (*ppos != 0)
627 goto out;
628
629 length = -ENOMEM;
630 page = (char *)get_zeroed_page(GFP_KERNEL);
631 if (!page)
632 goto out;
633
634 length = -EFAULT;
635 if (copy_from_user(page, buf, count))
636 goto out;
637
638 length = -EINVAL;
639 if (sscanf(page, "%u", &new_value) != 1)
640 goto out;
641
642 selinux_checkreqprot = new_value ? 1 : 0;
643 length = count;
644 out:
645 free_page((unsigned long) page);
646 return length;
647 }
648 static const struct file_operations sel_checkreqprot_ops = {
649 .read = sel_read_checkreqprot,
650 .write = sel_write_checkreqprot,
651 .llseek = generic_file_llseek,
652 };
653
654 /*
655 * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
656 */
657 static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
658 static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
659 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
660 static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
661 static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
662
663 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
664 [SEL_ACCESS] = sel_write_access,
665 [SEL_CREATE] = sel_write_create,
666 [SEL_RELABEL] = sel_write_relabel,
667 [SEL_USER] = sel_write_user,
668 [SEL_MEMBER] = sel_write_member,
669 [SEL_CONTEXT] = sel_write_context,
670 };
671
selinux_transaction_write(struct file * file,const char __user * buf,size_t size,loff_t * pos)672 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
673 {
674 ino_t ino = file_inode(file)->i_ino;
675 char *data;
676 ssize_t rv;
677
678 if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
679 return -EINVAL;
680
681 data = simple_transaction_get(file, buf, size);
682 if (IS_ERR(data))
683 return PTR_ERR(data);
684
685 rv = write_op[ino](file, data, size);
686 if (rv > 0) {
687 simple_transaction_set(file, rv);
688 rv = size;
689 }
690 return rv;
691 }
692
693 static const struct file_operations transaction_ops = {
694 .write = selinux_transaction_write,
695 .read = simple_transaction_read,
696 .release = simple_transaction_release,
697 .llseek = generic_file_llseek,
698 };
699
700 /*
701 * payload - write methods
702 * If the method has a response, the response should be put in buf,
703 * and the length returned. Otherwise return 0 or and -error.
704 */
705
sel_write_access(struct file * file,char * buf,size_t size)706 static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
707 {
708 char *scon = NULL, *tcon = NULL;
709 u32 ssid, tsid;
710 u16 tclass;
711 struct av_decision avd;
712 ssize_t length;
713
714 length = task_has_security(current, SECURITY__COMPUTE_AV);
715 if (length)
716 goto out;
717
718 length = -ENOMEM;
719 scon = kzalloc(size + 1, GFP_KERNEL);
720 if (!scon)
721 goto out;
722
723 length = -ENOMEM;
724 tcon = kzalloc(size + 1, GFP_KERNEL);
725 if (!tcon)
726 goto out;
727
728 length = -EINVAL;
729 if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
730 goto out;
731
732 length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
733 if (length)
734 goto out;
735
736 length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
737 if (length)
738 goto out;
739
740 security_compute_av_user(ssid, tsid, tclass, &avd);
741
742 length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
743 "%x %x %x %x %u %x",
744 avd.allowed, 0xffffffff,
745 avd.auditallow, avd.auditdeny,
746 avd.seqno, avd.flags);
747 out:
748 kfree(tcon);
749 kfree(scon);
750 return length;
751 }
752
sel_write_create(struct file * file,char * buf,size_t size)753 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
754 {
755 char *scon = NULL, *tcon = NULL;
756 char *namebuf = NULL, *objname = NULL;
757 u32 ssid, tsid, newsid;
758 u16 tclass;
759 ssize_t length;
760 char *newcon = NULL;
761 u32 len;
762 int nargs;
763
764 length = task_has_security(current, SECURITY__COMPUTE_CREATE);
765 if (length)
766 goto out;
767
768 length = -ENOMEM;
769 scon = kzalloc(size + 1, GFP_KERNEL);
770 if (!scon)
771 goto out;
772
773 length = -ENOMEM;
774 tcon = kzalloc(size + 1, GFP_KERNEL);
775 if (!tcon)
776 goto out;
777
778 length = -ENOMEM;
779 namebuf = kzalloc(size + 1, GFP_KERNEL);
780 if (!namebuf)
781 goto out;
782
783 length = -EINVAL;
784 nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
785 if (nargs < 3 || nargs > 4)
786 goto out;
787 if (nargs == 4) {
788 /*
789 * If and when the name of new object to be queried contains
790 * either whitespace or multibyte characters, they shall be
791 * encoded based on the percentage-encoding rule.
792 * If not encoded, the sscanf logic picks up only left-half
793 * of the supplied name; splitted by a whitespace unexpectedly.
794 */
795 char *r, *w;
796 int c1, c2;
797
798 r = w = namebuf;
799 do {
800 c1 = *r++;
801 if (c1 == '+')
802 c1 = ' ';
803 else if (c1 == '%') {
804 c1 = hex_to_bin(*r++);
805 if (c1 < 0)
806 goto out;
807 c2 = hex_to_bin(*r++);
808 if (c2 < 0)
809 goto out;
810 c1 = (c1 << 4) | c2;
811 }
812 *w++ = c1;
813 } while (c1 != '\0');
814
815 objname = namebuf;
816 }
817
818 length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
819 if (length)
820 goto out;
821
822 length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
823 if (length)
824 goto out;
825
826 length = security_transition_sid_user(ssid, tsid, tclass,
827 objname, &newsid);
828 if (length)
829 goto out;
830
831 length = security_sid_to_context(newsid, &newcon, &len);
832 if (length)
833 goto out;
834
835 length = -ERANGE;
836 if (len > SIMPLE_TRANSACTION_LIMIT) {
837 printk(KERN_ERR "SELinux: %s: context size (%u) exceeds "
838 "payload max\n", __func__, len);
839 goto out;
840 }
841
842 memcpy(buf, newcon, len);
843 length = len;
844 out:
845 kfree(newcon);
846 kfree(namebuf);
847 kfree(tcon);
848 kfree(scon);
849 return length;
850 }
851
sel_write_relabel(struct file * file,char * buf,size_t size)852 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
853 {
854 char *scon = NULL, *tcon = NULL;
855 u32 ssid, tsid, newsid;
856 u16 tclass;
857 ssize_t length;
858 char *newcon = NULL;
859 u32 len;
860
861 length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
862 if (length)
863 goto out;
864
865 length = -ENOMEM;
866 scon = kzalloc(size + 1, GFP_KERNEL);
867 if (!scon)
868 goto out;
869
870 length = -ENOMEM;
871 tcon = kzalloc(size + 1, GFP_KERNEL);
872 if (!tcon)
873 goto out;
874
875 length = -EINVAL;
876 if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
877 goto out;
878
879 length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
880 if (length)
881 goto out;
882
883 length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
884 if (length)
885 goto out;
886
887 length = security_change_sid(ssid, tsid, tclass, &newsid);
888 if (length)
889 goto out;
890
891 length = security_sid_to_context(newsid, &newcon, &len);
892 if (length)
893 goto out;
894
895 length = -ERANGE;
896 if (len > SIMPLE_TRANSACTION_LIMIT)
897 goto out;
898
899 memcpy(buf, newcon, len);
900 length = len;
901 out:
902 kfree(newcon);
903 kfree(tcon);
904 kfree(scon);
905 return length;
906 }
907
sel_write_user(struct file * file,char * buf,size_t size)908 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
909 {
910 char *con = NULL, *user = NULL, *ptr;
911 u32 sid, *sids = NULL;
912 ssize_t length;
913 char *newcon;
914 int i, rc;
915 u32 len, nsids;
916
917 length = task_has_security(current, SECURITY__COMPUTE_USER);
918 if (length)
919 goto out;
920
921 length = -ENOMEM;
922 con = kzalloc(size + 1, GFP_KERNEL);
923 if (!con)
924 goto out;
925
926 length = -ENOMEM;
927 user = kzalloc(size + 1, GFP_KERNEL);
928 if (!user)
929 goto out;
930
931 length = -EINVAL;
932 if (sscanf(buf, "%s %s", con, user) != 2)
933 goto out;
934
935 length = security_context_to_sid(con, strlen(con) + 1, &sid);
936 if (length)
937 goto out;
938
939 length = security_get_user_sids(sid, user, &sids, &nsids);
940 if (length)
941 goto out;
942
943 length = sprintf(buf, "%u", nsids) + 1;
944 ptr = buf + length;
945 for (i = 0; i < nsids; i++) {
946 rc = security_sid_to_context(sids[i], &newcon, &len);
947 if (rc) {
948 length = rc;
949 goto out;
950 }
951 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
952 kfree(newcon);
953 length = -ERANGE;
954 goto out;
955 }
956 memcpy(ptr, newcon, len);
957 kfree(newcon);
958 ptr += len;
959 length += len;
960 }
961 out:
962 kfree(sids);
963 kfree(user);
964 kfree(con);
965 return length;
966 }
967
sel_write_member(struct file * file,char * buf,size_t size)968 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
969 {
970 char *scon = NULL, *tcon = NULL;
971 u32 ssid, tsid, newsid;
972 u16 tclass;
973 ssize_t length;
974 char *newcon = NULL;
975 u32 len;
976
977 length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
978 if (length)
979 goto out;
980
981 length = -ENOMEM;
982 scon = kzalloc(size + 1, GFP_KERNEL);
983 if (!scon)
984 goto out;
985
986 length = -ENOMEM;
987 tcon = kzalloc(size + 1, GFP_KERNEL);
988 if (!tcon)
989 goto out;
990
991 length = -EINVAL;
992 if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
993 goto out;
994
995 length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
996 if (length)
997 goto out;
998
999 length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
1000 if (length)
1001 goto out;
1002
1003 length = security_member_sid(ssid, tsid, tclass, &newsid);
1004 if (length)
1005 goto out;
1006
1007 length = security_sid_to_context(newsid, &newcon, &len);
1008 if (length)
1009 goto out;
1010
1011 length = -ERANGE;
1012 if (len > SIMPLE_TRANSACTION_LIMIT) {
1013 printk(KERN_ERR "SELinux: %s: context size (%u) exceeds "
1014 "payload max\n", __func__, len);
1015 goto out;
1016 }
1017
1018 memcpy(buf, newcon, len);
1019 length = len;
1020 out:
1021 kfree(newcon);
1022 kfree(tcon);
1023 kfree(scon);
1024 return length;
1025 }
1026
sel_make_inode(struct super_block * sb,int mode)1027 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1028 {
1029 struct inode *ret = new_inode(sb);
1030
1031 if (ret) {
1032 ret->i_mode = mode;
1033 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
1034 }
1035 return ret;
1036 }
1037
sel_read_bool(struct file * filep,char __user * buf,size_t count,loff_t * ppos)1038 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1039 size_t count, loff_t *ppos)
1040 {
1041 char *page = NULL;
1042 ssize_t length;
1043 ssize_t ret;
1044 int cur_enforcing;
1045 unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1046 const char *name = filep->f_path.dentry->d_name.name;
1047
1048 mutex_lock(&sel_mutex);
1049
1050 ret = -EINVAL;
1051 if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1052 goto out;
1053
1054 ret = -ENOMEM;
1055 page = (char *)get_zeroed_page(GFP_KERNEL);
1056 if (!page)
1057 goto out;
1058
1059 cur_enforcing = security_get_bool_value(index);
1060 if (cur_enforcing < 0) {
1061 ret = cur_enforcing;
1062 goto out;
1063 }
1064 length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1065 bool_pending_values[index]);
1066 ret = simple_read_from_buffer(buf, count, ppos, page, length);
1067 out:
1068 mutex_unlock(&sel_mutex);
1069 free_page((unsigned long)page);
1070 return ret;
1071 }
1072
sel_write_bool(struct file * filep,const char __user * buf,size_t count,loff_t * ppos)1073 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1074 size_t count, loff_t *ppos)
1075 {
1076 char *page = NULL;
1077 ssize_t length;
1078 int new_value;
1079 unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1080 const char *name = filep->f_path.dentry->d_name.name;
1081
1082 mutex_lock(&sel_mutex);
1083
1084 length = task_has_security(current, SECURITY__SETBOOL);
1085 if (length)
1086 goto out;
1087
1088 length = -EINVAL;
1089 if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1090 goto out;
1091
1092 length = -ENOMEM;
1093 if (count >= PAGE_SIZE)
1094 goto out;
1095
1096 /* No partial writes. */
1097 length = -EINVAL;
1098 if (*ppos != 0)
1099 goto out;
1100
1101 length = -ENOMEM;
1102 page = (char *)get_zeroed_page(GFP_KERNEL);
1103 if (!page)
1104 goto out;
1105
1106 length = -EFAULT;
1107 if (copy_from_user(page, buf, count))
1108 goto out;
1109
1110 length = -EINVAL;
1111 if (sscanf(page, "%d", &new_value) != 1)
1112 goto out;
1113
1114 if (new_value)
1115 new_value = 1;
1116
1117 bool_pending_values[index] = new_value;
1118 length = count;
1119
1120 out:
1121 mutex_unlock(&sel_mutex);
1122 free_page((unsigned long) page);
1123 return length;
1124 }
1125
1126 static const struct file_operations sel_bool_ops = {
1127 .read = sel_read_bool,
1128 .write = sel_write_bool,
1129 .llseek = generic_file_llseek,
1130 };
1131
sel_commit_bools_write(struct file * filep,const char __user * buf,size_t count,loff_t * ppos)1132 static ssize_t sel_commit_bools_write(struct file *filep,
1133 const char __user *buf,
1134 size_t count, loff_t *ppos)
1135 {
1136 char *page = NULL;
1137 ssize_t length;
1138 int new_value;
1139
1140 mutex_lock(&sel_mutex);
1141
1142 length = task_has_security(current, SECURITY__SETBOOL);
1143 if (length)
1144 goto out;
1145
1146 length = -ENOMEM;
1147 if (count >= PAGE_SIZE)
1148 goto out;
1149
1150 /* No partial writes. */
1151 length = -EINVAL;
1152 if (*ppos != 0)
1153 goto out;
1154
1155 length = -ENOMEM;
1156 page = (char *)get_zeroed_page(GFP_KERNEL);
1157 if (!page)
1158 goto out;
1159
1160 length = -EFAULT;
1161 if (copy_from_user(page, buf, count))
1162 goto out;
1163
1164 length = -EINVAL;
1165 if (sscanf(page, "%d", &new_value) != 1)
1166 goto out;
1167
1168 length = 0;
1169 if (new_value && bool_pending_values)
1170 length = security_set_bools(bool_num, bool_pending_values);
1171
1172 if (!length)
1173 length = count;
1174
1175 out:
1176 mutex_unlock(&sel_mutex);
1177 free_page((unsigned long) page);
1178 return length;
1179 }
1180
1181 static const struct file_operations sel_commit_bools_ops = {
1182 .write = sel_commit_bools_write,
1183 .llseek = generic_file_llseek,
1184 };
1185
sel_remove_entries(struct dentry * de)1186 static void sel_remove_entries(struct dentry *de)
1187 {
1188 struct list_head *node;
1189
1190 spin_lock(&de->d_lock);
1191 node = de->d_subdirs.next;
1192 while (node != &de->d_subdirs) {
1193 struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
1194
1195 spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
1196 list_del_init(node);
1197
1198 if (d->d_inode) {
1199 dget_dlock(d);
1200 spin_unlock(&de->d_lock);
1201 spin_unlock(&d->d_lock);
1202 d_delete(d);
1203 simple_unlink(de->d_inode, d);
1204 dput(d);
1205 spin_lock(&de->d_lock);
1206 } else
1207 spin_unlock(&d->d_lock);
1208 node = de->d_subdirs.next;
1209 }
1210
1211 spin_unlock(&de->d_lock);
1212 }
1213
1214 #define BOOL_DIR_NAME "booleans"
1215
sel_make_bools(void)1216 static int sel_make_bools(void)
1217 {
1218 int i, ret;
1219 ssize_t len;
1220 struct dentry *dentry = NULL;
1221 struct dentry *dir = bool_dir;
1222 struct inode *inode = NULL;
1223 struct inode_security_struct *isec;
1224 char **names = NULL, *page;
1225 int num;
1226 int *values = NULL;
1227 u32 sid;
1228
1229 /* remove any existing files */
1230 for (i = 0; i < bool_num; i++)
1231 kfree(bool_pending_names[i]);
1232 kfree(bool_pending_names);
1233 kfree(bool_pending_values);
1234 bool_num = 0;
1235 bool_pending_names = NULL;
1236 bool_pending_values = NULL;
1237
1238 sel_remove_entries(dir);
1239
1240 ret = -ENOMEM;
1241 page = (char *)get_zeroed_page(GFP_KERNEL);
1242 if (!page)
1243 goto out;
1244
1245 ret = security_get_bools(&num, &names, &values);
1246 if (ret)
1247 goto out;
1248
1249 for (i = 0; i < num; i++) {
1250 ret = -ENOMEM;
1251 dentry = d_alloc_name(dir, names[i]);
1252 if (!dentry)
1253 goto out;
1254
1255 ret = -ENOMEM;
1256 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1257 if (!inode)
1258 goto out;
1259
1260 ret = -ENAMETOOLONG;
1261 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1262 if (len >= PAGE_SIZE)
1263 goto out;
1264
1265 isec = (struct inode_security_struct *)inode->i_security;
1266 ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1267 if (ret)
1268 goto out;
1269
1270 isec->sid = sid;
1271 isec->initialized = 1;
1272 inode->i_fop = &sel_bool_ops;
1273 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1274 d_add(dentry, inode);
1275 }
1276 bool_num = num;
1277 bool_pending_names = names;
1278 bool_pending_values = values;
1279
1280 free_page((unsigned long)page);
1281 return 0;
1282 out:
1283 free_page((unsigned long)page);
1284
1285 if (names) {
1286 for (i = 0; i < num; i++)
1287 kfree(names[i]);
1288 kfree(names);
1289 }
1290 kfree(values);
1291 sel_remove_entries(dir);
1292
1293 return ret;
1294 }
1295
1296 #define NULL_FILE_NAME "null"
1297
1298 struct path selinux_null;
1299
sel_read_avc_cache_threshold(struct file * filp,char __user * buf,size_t count,loff_t * ppos)1300 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1301 size_t count, loff_t *ppos)
1302 {
1303 char tmpbuf[TMPBUFLEN];
1304 ssize_t length;
1305
1306 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1307 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1308 }
1309
sel_write_avc_cache_threshold(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1310 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1311 const char __user *buf,
1312 size_t count, loff_t *ppos)
1313
1314 {
1315 char *page = NULL;
1316 ssize_t ret;
1317 int new_value;
1318
1319 ret = task_has_security(current, SECURITY__SETSECPARAM);
1320 if (ret)
1321 goto out;
1322
1323 ret = -ENOMEM;
1324 if (count >= PAGE_SIZE)
1325 goto out;
1326
1327 /* No partial writes. */
1328 ret = -EINVAL;
1329 if (*ppos != 0)
1330 goto out;
1331
1332 ret = -ENOMEM;
1333 page = (char *)get_zeroed_page(GFP_KERNEL);
1334 if (!page)
1335 goto out;
1336
1337 ret = -EFAULT;
1338 if (copy_from_user(page, buf, count))
1339 goto out;
1340
1341 ret = -EINVAL;
1342 if (sscanf(page, "%u", &new_value) != 1)
1343 goto out;
1344
1345 avc_cache_threshold = new_value;
1346
1347 ret = count;
1348 out:
1349 free_page((unsigned long)page);
1350 return ret;
1351 }
1352
sel_read_avc_hash_stats(struct file * filp,char __user * buf,size_t count,loff_t * ppos)1353 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1354 size_t count, loff_t *ppos)
1355 {
1356 char *page;
1357 ssize_t length;
1358
1359 page = (char *)__get_free_page(GFP_KERNEL);
1360 if (!page)
1361 return -ENOMEM;
1362
1363 length = avc_get_hash_stats(page);
1364 if (length >= 0)
1365 length = simple_read_from_buffer(buf, count, ppos, page, length);
1366 free_page((unsigned long)page);
1367
1368 return length;
1369 }
1370
1371 static const struct file_operations sel_avc_cache_threshold_ops = {
1372 .read = sel_read_avc_cache_threshold,
1373 .write = sel_write_avc_cache_threshold,
1374 .llseek = generic_file_llseek,
1375 };
1376
1377 static const struct file_operations sel_avc_hash_stats_ops = {
1378 .read = sel_read_avc_hash_stats,
1379 .llseek = generic_file_llseek,
1380 };
1381
1382 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
sel_avc_get_stat_idx(loff_t * idx)1383 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1384 {
1385 int cpu;
1386
1387 for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1388 if (!cpu_possible(cpu))
1389 continue;
1390 *idx = cpu + 1;
1391 return &per_cpu(avc_cache_stats, cpu);
1392 }
1393 return NULL;
1394 }
1395
sel_avc_stats_seq_start(struct seq_file * seq,loff_t * pos)1396 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1397 {
1398 loff_t n = *pos - 1;
1399
1400 if (*pos == 0)
1401 return SEQ_START_TOKEN;
1402
1403 return sel_avc_get_stat_idx(&n);
1404 }
1405
sel_avc_stats_seq_next(struct seq_file * seq,void * v,loff_t * pos)1406 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1407 {
1408 return sel_avc_get_stat_idx(pos);
1409 }
1410
sel_avc_stats_seq_show(struct seq_file * seq,void * v)1411 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1412 {
1413 struct avc_cache_stats *st = v;
1414
1415 if (v == SEQ_START_TOKEN)
1416 seq_printf(seq, "lookups hits misses allocations reclaims "
1417 "frees\n");
1418 else {
1419 unsigned int lookups = st->lookups;
1420 unsigned int misses = st->misses;
1421 unsigned int hits = lookups - misses;
1422 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1423 hits, misses, st->allocations,
1424 st->reclaims, st->frees);
1425 }
1426 return 0;
1427 }
1428
sel_avc_stats_seq_stop(struct seq_file * seq,void * v)1429 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1430 { }
1431
1432 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1433 .start = sel_avc_stats_seq_start,
1434 .next = sel_avc_stats_seq_next,
1435 .show = sel_avc_stats_seq_show,
1436 .stop = sel_avc_stats_seq_stop,
1437 };
1438
sel_open_avc_cache_stats(struct inode * inode,struct file * file)1439 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1440 {
1441 return seq_open(file, &sel_avc_cache_stats_seq_ops);
1442 }
1443
1444 static const struct file_operations sel_avc_cache_stats_ops = {
1445 .open = sel_open_avc_cache_stats,
1446 .read = seq_read,
1447 .llseek = seq_lseek,
1448 .release = seq_release,
1449 };
1450 #endif
1451
sel_make_avc_files(struct dentry * dir)1452 static int sel_make_avc_files(struct dentry *dir)
1453 {
1454 int i;
1455 static struct tree_descr files[] = {
1456 { "cache_threshold",
1457 &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1458 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1459 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1460 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1461 #endif
1462 };
1463
1464 for (i = 0; i < ARRAY_SIZE(files); i++) {
1465 struct inode *inode;
1466 struct dentry *dentry;
1467
1468 dentry = d_alloc_name(dir, files[i].name);
1469 if (!dentry)
1470 return -ENOMEM;
1471
1472 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1473 if (!inode)
1474 return -ENOMEM;
1475
1476 inode->i_fop = files[i].ops;
1477 inode->i_ino = ++sel_last_ino;
1478 d_add(dentry, inode);
1479 }
1480
1481 return 0;
1482 }
1483
sel_read_initcon(struct file * file,char __user * buf,size_t count,loff_t * ppos)1484 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1485 size_t count, loff_t *ppos)
1486 {
1487 char *con;
1488 u32 sid, len;
1489 ssize_t ret;
1490
1491 sid = file_inode(file)->i_ino&SEL_INO_MASK;
1492 ret = security_sid_to_context(sid, &con, &len);
1493 if (ret)
1494 return ret;
1495
1496 ret = simple_read_from_buffer(buf, count, ppos, con, len);
1497 kfree(con);
1498 return ret;
1499 }
1500
1501 static const struct file_operations sel_initcon_ops = {
1502 .read = sel_read_initcon,
1503 .llseek = generic_file_llseek,
1504 };
1505
sel_make_initcon_files(struct dentry * dir)1506 static int sel_make_initcon_files(struct dentry *dir)
1507 {
1508 int i;
1509
1510 for (i = 1; i <= SECINITSID_NUM; i++) {
1511 struct inode *inode;
1512 struct dentry *dentry;
1513 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1514 if (!dentry)
1515 return -ENOMEM;
1516
1517 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1518 if (!inode)
1519 return -ENOMEM;
1520
1521 inode->i_fop = &sel_initcon_ops;
1522 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1523 d_add(dentry, inode);
1524 }
1525
1526 return 0;
1527 }
1528
sel_class_to_ino(u16 class)1529 static inline unsigned long sel_class_to_ino(u16 class)
1530 {
1531 return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1532 }
1533
sel_ino_to_class(unsigned long ino)1534 static inline u16 sel_ino_to_class(unsigned long ino)
1535 {
1536 return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1537 }
1538
sel_perm_to_ino(u16 class,u32 perm)1539 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1540 {
1541 return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1542 }
1543
sel_ino_to_perm(unsigned long ino)1544 static inline u32 sel_ino_to_perm(unsigned long ino)
1545 {
1546 return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1547 }
1548
sel_read_class(struct file * file,char __user * buf,size_t count,loff_t * ppos)1549 static ssize_t sel_read_class(struct file *file, char __user *buf,
1550 size_t count, loff_t *ppos)
1551 {
1552 unsigned long ino = file_inode(file)->i_ino;
1553 char res[TMPBUFLEN];
1554 ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1555 return simple_read_from_buffer(buf, count, ppos, res, len);
1556 }
1557
1558 static const struct file_operations sel_class_ops = {
1559 .read = sel_read_class,
1560 .llseek = generic_file_llseek,
1561 };
1562
sel_read_perm(struct file * file,char __user * buf,size_t count,loff_t * ppos)1563 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1564 size_t count, loff_t *ppos)
1565 {
1566 unsigned long ino = file_inode(file)->i_ino;
1567 char res[TMPBUFLEN];
1568 ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1569 return simple_read_from_buffer(buf, count, ppos, res, len);
1570 }
1571
1572 static const struct file_operations sel_perm_ops = {
1573 .read = sel_read_perm,
1574 .llseek = generic_file_llseek,
1575 };
1576
sel_read_policycap(struct file * file,char __user * buf,size_t count,loff_t * ppos)1577 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1578 size_t count, loff_t *ppos)
1579 {
1580 int value;
1581 char tmpbuf[TMPBUFLEN];
1582 ssize_t length;
1583 unsigned long i_ino = file_inode(file)->i_ino;
1584
1585 value = security_policycap_supported(i_ino & SEL_INO_MASK);
1586 length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1587
1588 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1589 }
1590
1591 static const struct file_operations sel_policycap_ops = {
1592 .read = sel_read_policycap,
1593 .llseek = generic_file_llseek,
1594 };
1595
sel_make_perm_files(char * objclass,int classvalue,struct dentry * dir)1596 static int sel_make_perm_files(char *objclass, int classvalue,
1597 struct dentry *dir)
1598 {
1599 int i, rc, nperms;
1600 char **perms;
1601
1602 rc = security_get_permissions(objclass, &perms, &nperms);
1603 if (rc)
1604 return rc;
1605
1606 for (i = 0; i < nperms; i++) {
1607 struct inode *inode;
1608 struct dentry *dentry;
1609
1610 rc = -ENOMEM;
1611 dentry = d_alloc_name(dir, perms[i]);
1612 if (!dentry)
1613 goto out;
1614
1615 rc = -ENOMEM;
1616 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1617 if (!inode)
1618 goto out;
1619
1620 inode->i_fop = &sel_perm_ops;
1621 /* i+1 since perm values are 1-indexed */
1622 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1623 d_add(dentry, inode);
1624 }
1625 rc = 0;
1626 out:
1627 for (i = 0; i < nperms; i++)
1628 kfree(perms[i]);
1629 kfree(perms);
1630 return rc;
1631 }
1632
sel_make_class_dir_entries(char * classname,int index,struct dentry * dir)1633 static int sel_make_class_dir_entries(char *classname, int index,
1634 struct dentry *dir)
1635 {
1636 struct dentry *dentry = NULL;
1637 struct inode *inode = NULL;
1638 int rc;
1639
1640 dentry = d_alloc_name(dir, "index");
1641 if (!dentry)
1642 return -ENOMEM;
1643
1644 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1645 if (!inode)
1646 return -ENOMEM;
1647
1648 inode->i_fop = &sel_class_ops;
1649 inode->i_ino = sel_class_to_ino(index);
1650 d_add(dentry, inode);
1651
1652 dentry = sel_make_dir(dir, "perms", &last_class_ino);
1653 if (IS_ERR(dentry))
1654 return PTR_ERR(dentry);
1655
1656 rc = sel_make_perm_files(classname, index, dentry);
1657
1658 return rc;
1659 }
1660
sel_remove_classes(void)1661 static void sel_remove_classes(void)
1662 {
1663 struct list_head *class_node;
1664
1665 list_for_each(class_node, &class_dir->d_subdirs) {
1666 struct dentry *class_subdir = list_entry(class_node,
1667 struct dentry, d_u.d_child);
1668 struct list_head *class_subdir_node;
1669
1670 list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
1671 struct dentry *d = list_entry(class_subdir_node,
1672 struct dentry, d_u.d_child);
1673
1674 if (d->d_inode)
1675 if (d->d_inode->i_mode & S_IFDIR)
1676 sel_remove_entries(d);
1677 }
1678
1679 sel_remove_entries(class_subdir);
1680 }
1681
1682 sel_remove_entries(class_dir);
1683 }
1684
sel_make_classes(void)1685 static int sel_make_classes(void)
1686 {
1687 int rc, nclasses, i;
1688 char **classes;
1689
1690 /* delete any existing entries */
1691 sel_remove_classes();
1692
1693 rc = security_get_classes(&classes, &nclasses);
1694 if (rc)
1695 return rc;
1696
1697 /* +2 since classes are 1-indexed */
1698 last_class_ino = sel_class_to_ino(nclasses + 2);
1699
1700 for (i = 0; i < nclasses; i++) {
1701 struct dentry *class_name_dir;
1702
1703 class_name_dir = sel_make_dir(class_dir, classes[i],
1704 &last_class_ino);
1705 if (IS_ERR(class_name_dir)) {
1706 rc = PTR_ERR(class_name_dir);
1707 goto out;
1708 }
1709
1710 /* i+1 since class values are 1-indexed */
1711 rc = sel_make_class_dir_entries(classes[i], i + 1,
1712 class_name_dir);
1713 if (rc)
1714 goto out;
1715 }
1716 rc = 0;
1717 out:
1718 for (i = 0; i < nclasses; i++)
1719 kfree(classes[i]);
1720 kfree(classes);
1721 return rc;
1722 }
1723
sel_make_policycap(void)1724 static int sel_make_policycap(void)
1725 {
1726 unsigned int iter;
1727 struct dentry *dentry = NULL;
1728 struct inode *inode = NULL;
1729
1730 sel_remove_entries(policycap_dir);
1731
1732 for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1733 if (iter < ARRAY_SIZE(policycap_names))
1734 dentry = d_alloc_name(policycap_dir,
1735 policycap_names[iter]);
1736 else
1737 dentry = d_alloc_name(policycap_dir, "unknown");
1738
1739 if (dentry == NULL)
1740 return -ENOMEM;
1741
1742 inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1743 if (inode == NULL)
1744 return -ENOMEM;
1745
1746 inode->i_fop = &sel_policycap_ops;
1747 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1748 d_add(dentry, inode);
1749 }
1750
1751 return 0;
1752 }
1753
sel_make_dir(struct dentry * dir,const char * name,unsigned long * ino)1754 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1755 unsigned long *ino)
1756 {
1757 struct dentry *dentry = d_alloc_name(dir, name);
1758 struct inode *inode;
1759
1760 if (!dentry)
1761 return ERR_PTR(-ENOMEM);
1762
1763 inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1764 if (!inode) {
1765 dput(dentry);
1766 return ERR_PTR(-ENOMEM);
1767 }
1768
1769 inode->i_op = &simple_dir_inode_operations;
1770 inode->i_fop = &simple_dir_operations;
1771 inode->i_ino = ++(*ino);
1772 /* directory inodes start off with i_nlink == 2 (for "." entry) */
1773 inc_nlink(inode);
1774 d_add(dentry, inode);
1775 /* bump link count on parent directory, too */
1776 inc_nlink(dir->d_inode);
1777
1778 return dentry;
1779 }
1780
sel_fill_super(struct super_block * sb,void * data,int silent)1781 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1782 {
1783 int ret;
1784 struct dentry *dentry;
1785 struct inode *inode;
1786 struct inode_security_struct *isec;
1787
1788 static struct tree_descr selinux_files[] = {
1789 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1790 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1791 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1792 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1793 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1794 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1795 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1796 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1797 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1798 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1799 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1800 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1801 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1802 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1803 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1804 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1805 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1806 /* last one */ {""}
1807 };
1808 ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1809 if (ret)
1810 goto err;
1811
1812 bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino);
1813 if (IS_ERR(bool_dir)) {
1814 ret = PTR_ERR(bool_dir);
1815 bool_dir = NULL;
1816 goto err;
1817 }
1818
1819 ret = -ENOMEM;
1820 dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1821 if (!dentry)
1822 goto err;
1823
1824 ret = -ENOMEM;
1825 inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1826 if (!inode)
1827 goto err;
1828
1829 inode->i_ino = ++sel_last_ino;
1830 isec = (struct inode_security_struct *)inode->i_security;
1831 isec->sid = SECINITSID_DEVNULL;
1832 isec->sclass = SECCLASS_CHR_FILE;
1833 isec->initialized = 1;
1834
1835 init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1836 d_add(dentry, inode);
1837 selinux_null.dentry = dentry;
1838
1839 dentry = sel_make_dir(sb->s_root, "avc", &sel_last_ino);
1840 if (IS_ERR(dentry)) {
1841 ret = PTR_ERR(dentry);
1842 goto err;
1843 }
1844
1845 ret = sel_make_avc_files(dentry);
1846 if (ret)
1847 goto err;
1848
1849 dentry = sel_make_dir(sb->s_root, "initial_contexts", &sel_last_ino);
1850 if (IS_ERR(dentry)) {
1851 ret = PTR_ERR(dentry);
1852 goto err;
1853 }
1854
1855 ret = sel_make_initcon_files(dentry);
1856 if (ret)
1857 goto err;
1858
1859 class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino);
1860 if (IS_ERR(class_dir)) {
1861 ret = PTR_ERR(class_dir);
1862 class_dir = NULL;
1863 goto err;
1864 }
1865
1866 policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino);
1867 if (IS_ERR(policycap_dir)) {
1868 ret = PTR_ERR(policycap_dir);
1869 policycap_dir = NULL;
1870 goto err;
1871 }
1872 return 0;
1873 err:
1874 printk(KERN_ERR "SELinux: %s: failed while creating inodes\n",
1875 __func__);
1876 return ret;
1877 }
1878
sel_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)1879 static struct dentry *sel_mount(struct file_system_type *fs_type,
1880 int flags, const char *dev_name, void *data)
1881 {
1882 return mount_single(fs_type, flags, data, sel_fill_super);
1883 }
1884
1885 static struct file_system_type sel_fs_type = {
1886 .name = "selinuxfs",
1887 .mount = sel_mount,
1888 .kill_sb = kill_litter_super,
1889 };
1890
1891 struct vfsmount *selinuxfs_mount;
1892 static struct kobject *selinuxfs_kobj;
1893
init_sel_fs(void)1894 static int __init init_sel_fs(void)
1895 {
1896 int err;
1897
1898 if (!selinux_enabled)
1899 return 0;
1900
1901 selinuxfs_kobj = kobject_create_and_add("selinux", fs_kobj);
1902 if (!selinuxfs_kobj)
1903 return -ENOMEM;
1904
1905 err = register_filesystem(&sel_fs_type);
1906 if (err) {
1907 kobject_put(selinuxfs_kobj);
1908 return err;
1909 }
1910
1911 selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
1912 if (IS_ERR(selinuxfs_mount)) {
1913 printk(KERN_ERR "selinuxfs: could not mount!\n");
1914 err = PTR_ERR(selinuxfs_mount);
1915 selinuxfs_mount = NULL;
1916 }
1917
1918 return err;
1919 }
1920
1921 __initcall(init_sel_fs);
1922
1923 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
exit_sel_fs(void)1924 void exit_sel_fs(void)
1925 {
1926 kobject_put(selinuxfs_kobj);
1927 kern_unmount(selinuxfs_mount);
1928 unregister_filesystem(&sel_fs_type);
1929 }
1930 #endif
1931