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 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 = filp->f_path.dentry->d_inode->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 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_RESERVED;
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 };
500
sel_write_load(struct file * file,const char __user * buf,size_t count,loff_t * ppos)501 static ssize_t sel_write_load(struct file *file, const char __user *buf,
502 size_t count, loff_t *ppos)
503
504 {
505 ssize_t length;
506 void *data = NULL;
507
508 mutex_lock(&sel_mutex);
509
510 length = task_has_security(current, SECURITY__LOAD_POLICY);
511 if (length)
512 goto out;
513
514 /* No partial writes. */
515 length = -EINVAL;
516 if (*ppos != 0)
517 goto out;
518
519 length = -EFBIG;
520 if (count > 64 * 1024 * 1024)
521 goto out;
522
523 length = -ENOMEM;
524 data = vmalloc(count);
525 if (!data)
526 goto out;
527
528 length = -EFAULT;
529 if (copy_from_user(data, buf, count) != 0)
530 goto out;
531
532 length = security_load_policy(data, count);
533 if (length)
534 goto out;
535
536 length = sel_make_bools();
537 if (length)
538 goto out1;
539
540 length = sel_make_classes();
541 if (length)
542 goto out1;
543
544 length = sel_make_policycap();
545 if (length)
546 goto out1;
547
548 length = count;
549
550 out1:
551 audit_log(current->audit_context, GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
552 "policy loaded auid=%u ses=%u",
553 audit_get_loginuid(current),
554 audit_get_sessionid(current));
555 out:
556 mutex_unlock(&sel_mutex);
557 vfree(data);
558 return length;
559 }
560
561 static const struct file_operations sel_load_ops = {
562 .write = sel_write_load,
563 .llseek = generic_file_llseek,
564 };
565
sel_write_context(struct file * file,char * buf,size_t size)566 static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
567 {
568 char *canon = NULL;
569 u32 sid, len;
570 ssize_t length;
571
572 length = task_has_security(current, SECURITY__CHECK_CONTEXT);
573 if (length)
574 goto out;
575
576 length = security_context_to_sid(buf, size, &sid);
577 if (length)
578 goto out;
579
580 length = security_sid_to_context(sid, &canon, &len);
581 if (length)
582 goto out;
583
584 length = -ERANGE;
585 if (len > SIMPLE_TRANSACTION_LIMIT) {
586 printk(KERN_ERR "SELinux: %s: context size (%u) exceeds "
587 "payload max\n", __func__, len);
588 goto out;
589 }
590
591 memcpy(buf, canon, len);
592 length = len;
593 out:
594 kfree(canon);
595 return length;
596 }
597
sel_read_checkreqprot(struct file * filp,char __user * buf,size_t count,loff_t * ppos)598 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
599 size_t count, loff_t *ppos)
600 {
601 char tmpbuf[TMPBUFLEN];
602 ssize_t length;
603
604 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", selinux_checkreqprot);
605 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
606 }
607
sel_write_checkreqprot(struct file * file,const char __user * buf,size_t count,loff_t * ppos)608 static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
609 size_t count, loff_t *ppos)
610 {
611 char *page = NULL;
612 ssize_t length;
613 unsigned int new_value;
614
615 length = task_has_security(current, SECURITY__SETCHECKREQPROT);
616 if (length)
617 goto out;
618
619 length = -ENOMEM;
620 if (count >= PAGE_SIZE)
621 goto out;
622
623 /* No partial writes. */
624 length = -EINVAL;
625 if (*ppos != 0)
626 goto out;
627
628 length = -ENOMEM;
629 page = (char *)get_zeroed_page(GFP_KERNEL);
630 if (!page)
631 goto out;
632
633 length = -EFAULT;
634 if (copy_from_user(page, buf, count))
635 goto out;
636
637 length = -EINVAL;
638 if (sscanf(page, "%u", &new_value) != 1)
639 goto out;
640
641 selinux_checkreqprot = new_value ? 1 : 0;
642 length = count;
643 out:
644 free_page((unsigned long) page);
645 return length;
646 }
647 static const struct file_operations sel_checkreqprot_ops = {
648 .read = sel_read_checkreqprot,
649 .write = sel_write_checkreqprot,
650 .llseek = generic_file_llseek,
651 };
652
653 /*
654 * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
655 */
656 static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
657 static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
658 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
659 static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
660 static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
661
662 static ssize_t (*write_op[])(struct file *, char *, size_t) = {
663 [SEL_ACCESS] = sel_write_access,
664 [SEL_CREATE] = sel_write_create,
665 [SEL_RELABEL] = sel_write_relabel,
666 [SEL_USER] = sel_write_user,
667 [SEL_MEMBER] = sel_write_member,
668 [SEL_CONTEXT] = sel_write_context,
669 };
670
selinux_transaction_write(struct file * file,const char __user * buf,size_t size,loff_t * pos)671 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
672 {
673 ino_t ino = file->f_path.dentry->d_inode->i_ino;
674 char *data;
675 ssize_t rv;
676
677 if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
678 return -EINVAL;
679
680 data = simple_transaction_get(file, buf, size);
681 if (IS_ERR(data))
682 return PTR_ERR(data);
683
684 rv = write_op[ino](file, data, size);
685 if (rv > 0) {
686 simple_transaction_set(file, rv);
687 rv = size;
688 }
689 return rv;
690 }
691
692 static const struct file_operations transaction_ops = {
693 .write = selinux_transaction_write,
694 .read = simple_transaction_read,
695 .release = simple_transaction_release,
696 .llseek = generic_file_llseek,
697 };
698
699 /*
700 * payload - write methods
701 * If the method has a response, the response should be put in buf,
702 * and the length returned. Otherwise return 0 or and -error.
703 */
704
sel_write_access(struct file * file,char * buf,size_t size)705 static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
706 {
707 char *scon = NULL, *tcon = NULL;
708 u32 ssid, tsid;
709 u16 tclass;
710 struct av_decision avd;
711 ssize_t length;
712
713 length = task_has_security(current, SECURITY__COMPUTE_AV);
714 if (length)
715 goto out;
716
717 length = -ENOMEM;
718 scon = kzalloc(size + 1, GFP_KERNEL);
719 if (!scon)
720 goto out;
721
722 length = -ENOMEM;
723 tcon = kzalloc(size + 1, GFP_KERNEL);
724 if (!tcon)
725 goto out;
726
727 length = -EINVAL;
728 if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
729 goto out;
730
731 length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
732 if (length)
733 goto out;
734
735 length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
736 if (length)
737 goto out;
738
739 security_compute_av_user(ssid, tsid, tclass, &avd);
740
741 length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
742 "%x %x %x %x %u %x",
743 avd.allowed, 0xffffffff,
744 avd.auditallow, avd.auditdeny,
745 avd.seqno, avd.flags);
746 out:
747 kfree(tcon);
748 kfree(scon);
749 return length;
750 }
751
sel_write_create(struct file * file,char * buf,size_t size)752 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
753 {
754 char *scon = NULL, *tcon = NULL;
755 char *namebuf = NULL, *objname = NULL;
756 u32 ssid, tsid, newsid;
757 u16 tclass;
758 ssize_t length;
759 char *newcon = NULL;
760 u32 len;
761 int nargs;
762
763 length = task_has_security(current, SECURITY__COMPUTE_CREATE);
764 if (length)
765 goto out;
766
767 length = -ENOMEM;
768 scon = kzalloc(size + 1, GFP_KERNEL);
769 if (!scon)
770 goto out;
771
772 length = -ENOMEM;
773 tcon = kzalloc(size + 1, GFP_KERNEL);
774 if (!tcon)
775 goto out;
776
777 length = -ENOMEM;
778 namebuf = kzalloc(size + 1, GFP_KERNEL);
779 if (!namebuf)
780 goto out;
781
782 length = -EINVAL;
783 nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
784 if (nargs < 3 || nargs > 4)
785 goto out;
786 if (nargs == 4) {
787 /*
788 * If and when the name of new object to be queried contains
789 * either whitespace or multibyte characters, they shall be
790 * encoded based on the percentage-encoding rule.
791 * If not encoded, the sscanf logic picks up only left-half
792 * of the supplied name; splitted by a whitespace unexpectedly.
793 */
794 char *r, *w;
795 int c1, c2;
796
797 r = w = namebuf;
798 do {
799 c1 = *r++;
800 if (c1 == '+')
801 c1 = ' ';
802 else if (c1 == '%') {
803 c1 = hex_to_bin(*r++);
804 if (c1 < 0)
805 goto out;
806 c2 = hex_to_bin(*r++);
807 if (c2 < 0)
808 goto out;
809 c1 = (c1 << 4) | c2;
810 }
811 *w++ = c1;
812 } while (c1 != '\0');
813
814 objname = namebuf;
815 }
816
817 length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
818 if (length)
819 goto out;
820
821 length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
822 if (length)
823 goto out;
824
825 length = security_transition_sid_user(ssid, tsid, tclass,
826 objname, &newsid);
827 if (length)
828 goto out;
829
830 length = security_sid_to_context(newsid, &newcon, &len);
831 if (length)
832 goto out;
833
834 length = -ERANGE;
835 if (len > SIMPLE_TRANSACTION_LIMIT) {
836 printk(KERN_ERR "SELinux: %s: context size (%u) exceeds "
837 "payload max\n", __func__, len);
838 goto out;
839 }
840
841 memcpy(buf, newcon, len);
842 length = len;
843 out:
844 kfree(newcon);
845 kfree(namebuf);
846 kfree(tcon);
847 kfree(scon);
848 return length;
849 }
850
sel_write_relabel(struct file * file,char * buf,size_t size)851 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
852 {
853 char *scon = NULL, *tcon = NULL;
854 u32 ssid, tsid, newsid;
855 u16 tclass;
856 ssize_t length;
857 char *newcon = NULL;
858 u32 len;
859
860 length = task_has_security(current, SECURITY__COMPUTE_RELABEL);
861 if (length)
862 goto out;
863
864 length = -ENOMEM;
865 scon = kzalloc(size + 1, GFP_KERNEL);
866 if (!scon)
867 goto out;
868
869 length = -ENOMEM;
870 tcon = kzalloc(size + 1, GFP_KERNEL);
871 if (!tcon)
872 goto out;
873
874 length = -EINVAL;
875 if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
876 goto out;
877
878 length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
879 if (length)
880 goto out;
881
882 length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
883 if (length)
884 goto out;
885
886 length = security_change_sid(ssid, tsid, tclass, &newsid);
887 if (length)
888 goto out;
889
890 length = security_sid_to_context(newsid, &newcon, &len);
891 if (length)
892 goto out;
893
894 length = -ERANGE;
895 if (len > SIMPLE_TRANSACTION_LIMIT)
896 goto out;
897
898 memcpy(buf, newcon, len);
899 length = len;
900 out:
901 kfree(newcon);
902 kfree(tcon);
903 kfree(scon);
904 return length;
905 }
906
sel_write_user(struct file * file,char * buf,size_t size)907 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
908 {
909 char *con = NULL, *user = NULL, *ptr;
910 u32 sid, *sids = NULL;
911 ssize_t length;
912 char *newcon;
913 int i, rc;
914 u32 len, nsids;
915
916 length = task_has_security(current, SECURITY__COMPUTE_USER);
917 if (length)
918 goto out;
919
920 length = -ENOMEM;
921 con = kzalloc(size + 1, GFP_KERNEL);
922 if (!con)
923 goto out;
924
925 length = -ENOMEM;
926 user = kzalloc(size + 1, GFP_KERNEL);
927 if (!user)
928 goto out;
929
930 length = -EINVAL;
931 if (sscanf(buf, "%s %s", con, user) != 2)
932 goto out;
933
934 length = security_context_to_sid(con, strlen(con) + 1, &sid);
935 if (length)
936 goto out;
937
938 length = security_get_user_sids(sid, user, &sids, &nsids);
939 if (length)
940 goto out;
941
942 length = sprintf(buf, "%u", nsids) + 1;
943 ptr = buf + length;
944 for (i = 0; i < nsids; i++) {
945 rc = security_sid_to_context(sids[i], &newcon, &len);
946 if (rc) {
947 length = rc;
948 goto out;
949 }
950 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
951 kfree(newcon);
952 length = -ERANGE;
953 goto out;
954 }
955 memcpy(ptr, newcon, len);
956 kfree(newcon);
957 ptr += len;
958 length += len;
959 }
960 out:
961 kfree(sids);
962 kfree(user);
963 kfree(con);
964 return length;
965 }
966
sel_write_member(struct file * file,char * buf,size_t size)967 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
968 {
969 char *scon = NULL, *tcon = NULL;
970 u32 ssid, tsid, newsid;
971 u16 tclass;
972 ssize_t length;
973 char *newcon = NULL;
974 u32 len;
975
976 length = task_has_security(current, SECURITY__COMPUTE_MEMBER);
977 if (length)
978 goto out;
979
980 length = -ENOMEM;
981 scon = kzalloc(size + 1, GFP_KERNEL);
982 if (!scon)
983 goto out;
984
985 length = -ENOMEM;
986 tcon = kzalloc(size + 1, GFP_KERNEL);
987 if (!tcon)
988 goto out;
989
990 length = -EINVAL;
991 if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
992 goto out;
993
994 length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
995 if (length)
996 goto out;
997
998 length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
999 if (length)
1000 goto out;
1001
1002 length = security_member_sid(ssid, tsid, tclass, &newsid);
1003 if (length)
1004 goto out;
1005
1006 length = security_sid_to_context(newsid, &newcon, &len);
1007 if (length)
1008 goto out;
1009
1010 length = -ERANGE;
1011 if (len > SIMPLE_TRANSACTION_LIMIT) {
1012 printk(KERN_ERR "SELinux: %s: context size (%u) exceeds "
1013 "payload max\n", __func__, len);
1014 goto out;
1015 }
1016
1017 memcpy(buf, newcon, len);
1018 length = len;
1019 out:
1020 kfree(newcon);
1021 kfree(tcon);
1022 kfree(scon);
1023 return length;
1024 }
1025
sel_make_inode(struct super_block * sb,int mode)1026 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1027 {
1028 struct inode *ret = new_inode(sb);
1029
1030 if (ret) {
1031 ret->i_mode = mode;
1032 ret->i_atime = ret->i_mtime = ret->i_ctime = CURRENT_TIME;
1033 }
1034 return ret;
1035 }
1036
sel_read_bool(struct file * filep,char __user * buf,size_t count,loff_t * ppos)1037 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1038 size_t count, loff_t *ppos)
1039 {
1040 char *page = NULL;
1041 ssize_t length;
1042 ssize_t ret;
1043 int cur_enforcing;
1044 struct inode *inode = filep->f_path.dentry->d_inode;
1045 unsigned index = inode->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 struct inode *inode = filep->f_path.dentry->d_inode;
1080 unsigned index = inode->i_ino & SEL_INO_MASK;
1081 const char *name = filep->f_path.dentry->d_name.name;
1082
1083 mutex_lock(&sel_mutex);
1084
1085 length = task_has_security(current, SECURITY__SETBOOL);
1086 if (length)
1087 goto out;
1088
1089 length = -EINVAL;
1090 if (index >= bool_num || strcmp(name, bool_pending_names[index]))
1091 goto out;
1092
1093 length = -ENOMEM;
1094 if (count >= PAGE_SIZE)
1095 goto out;
1096
1097 /* No partial writes. */
1098 length = -EINVAL;
1099 if (*ppos != 0)
1100 goto out;
1101
1102 length = -ENOMEM;
1103 page = (char *)get_zeroed_page(GFP_KERNEL);
1104 if (!page)
1105 goto out;
1106
1107 length = -EFAULT;
1108 if (copy_from_user(page, buf, count))
1109 goto out;
1110
1111 length = -EINVAL;
1112 if (sscanf(page, "%d", &new_value) != 1)
1113 goto out;
1114
1115 if (new_value)
1116 new_value = 1;
1117
1118 bool_pending_values[index] = new_value;
1119 length = count;
1120
1121 out:
1122 mutex_unlock(&sel_mutex);
1123 free_page((unsigned long) page);
1124 return length;
1125 }
1126
1127 static const struct file_operations sel_bool_ops = {
1128 .read = sel_read_bool,
1129 .write = sel_write_bool,
1130 .llseek = generic_file_llseek,
1131 };
1132
sel_commit_bools_write(struct file * filep,const char __user * buf,size_t count,loff_t * ppos)1133 static ssize_t sel_commit_bools_write(struct file *filep,
1134 const char __user *buf,
1135 size_t count, loff_t *ppos)
1136 {
1137 char *page = NULL;
1138 ssize_t length;
1139 int new_value;
1140
1141 mutex_lock(&sel_mutex);
1142
1143 length = task_has_security(current, SECURITY__SETBOOL);
1144 if (length)
1145 goto out;
1146
1147 length = -ENOMEM;
1148 if (count >= PAGE_SIZE)
1149 goto out;
1150
1151 /* No partial writes. */
1152 length = -EINVAL;
1153 if (*ppos != 0)
1154 goto out;
1155
1156 length = -ENOMEM;
1157 page = (char *)get_zeroed_page(GFP_KERNEL);
1158 if (!page)
1159 goto out;
1160
1161 length = -EFAULT;
1162 if (copy_from_user(page, buf, count))
1163 goto out;
1164
1165 length = -EINVAL;
1166 if (sscanf(page, "%d", &new_value) != 1)
1167 goto out;
1168
1169 length = 0;
1170 if (new_value && bool_pending_values)
1171 length = security_set_bools(bool_num, bool_pending_values);
1172
1173 if (!length)
1174 length = count;
1175
1176 out:
1177 mutex_unlock(&sel_mutex);
1178 free_page((unsigned long) page);
1179 return length;
1180 }
1181
1182 static const struct file_operations sel_commit_bools_ops = {
1183 .write = sel_commit_bools_write,
1184 .llseek = generic_file_llseek,
1185 };
1186
sel_remove_entries(struct dentry * de)1187 static void sel_remove_entries(struct dentry *de)
1188 {
1189 struct list_head *node;
1190
1191 spin_lock(&de->d_lock);
1192 node = de->d_subdirs.next;
1193 while (node != &de->d_subdirs) {
1194 struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
1195
1196 spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
1197 list_del_init(node);
1198
1199 if (d->d_inode) {
1200 dget_dlock(d);
1201 spin_unlock(&de->d_lock);
1202 spin_unlock(&d->d_lock);
1203 d_delete(d);
1204 simple_unlink(de->d_inode, d);
1205 dput(d);
1206 spin_lock(&de->d_lock);
1207 } else
1208 spin_unlock(&d->d_lock);
1209 node = de->d_subdirs.next;
1210 }
1211
1212 spin_unlock(&de->d_lock);
1213 }
1214
1215 #define BOOL_DIR_NAME "booleans"
1216
sel_make_bools(void)1217 static int sel_make_bools(void)
1218 {
1219 int i, ret;
1220 ssize_t len;
1221 struct dentry *dentry = NULL;
1222 struct dentry *dir = bool_dir;
1223 struct inode *inode = NULL;
1224 struct inode_security_struct *isec;
1225 char **names = NULL, *page;
1226 int num;
1227 int *values = NULL;
1228 u32 sid;
1229
1230 /* remove any existing files */
1231 for (i = 0; i < bool_num; i++)
1232 kfree(bool_pending_names[i]);
1233 kfree(bool_pending_names);
1234 kfree(bool_pending_values);
1235 bool_num = 0;
1236 bool_pending_names = NULL;
1237 bool_pending_values = NULL;
1238
1239 sel_remove_entries(dir);
1240
1241 ret = -ENOMEM;
1242 page = (char *)get_zeroed_page(GFP_KERNEL);
1243 if (!page)
1244 goto out;
1245
1246 ret = security_get_bools(&num, &names, &values);
1247 if (ret)
1248 goto out;
1249
1250 for (i = 0; i < num; i++) {
1251 ret = -ENOMEM;
1252 dentry = d_alloc_name(dir, names[i]);
1253 if (!dentry)
1254 goto out;
1255
1256 ret = -ENOMEM;
1257 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1258 if (!inode)
1259 goto out;
1260
1261 ret = -EINVAL;
1262 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1263 if (len < 0)
1264 goto out;
1265
1266 ret = -ENAMETOOLONG;
1267 if (len >= PAGE_SIZE)
1268 goto out;
1269
1270 isec = (struct inode_security_struct *)inode->i_security;
1271 ret = security_genfs_sid("selinuxfs", page, SECCLASS_FILE, &sid);
1272 if (ret)
1273 goto out;
1274
1275 isec->sid = sid;
1276 isec->initialized = 1;
1277 inode->i_fop = &sel_bool_ops;
1278 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1279 d_add(dentry, inode);
1280 }
1281 bool_num = num;
1282 bool_pending_names = names;
1283 bool_pending_values = values;
1284
1285 free_page((unsigned long)page);
1286 return 0;
1287 out:
1288 free_page((unsigned long)page);
1289
1290 if (names) {
1291 for (i = 0; i < num; i++)
1292 kfree(names[i]);
1293 kfree(names);
1294 }
1295 kfree(values);
1296 sel_remove_entries(dir);
1297
1298 return ret;
1299 }
1300
1301 #define NULL_FILE_NAME "null"
1302
1303 struct dentry *selinux_null;
1304
sel_read_avc_cache_threshold(struct file * filp,char __user * buf,size_t count,loff_t * ppos)1305 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1306 size_t count, loff_t *ppos)
1307 {
1308 char tmpbuf[TMPBUFLEN];
1309 ssize_t length;
1310
1311 length = scnprintf(tmpbuf, TMPBUFLEN, "%u", avc_cache_threshold);
1312 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1313 }
1314
sel_write_avc_cache_threshold(struct file * file,const char __user * buf,size_t count,loff_t * ppos)1315 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1316 const char __user *buf,
1317 size_t count, loff_t *ppos)
1318
1319 {
1320 char *page = NULL;
1321 ssize_t ret;
1322 int new_value;
1323
1324 ret = task_has_security(current, SECURITY__SETSECPARAM);
1325 if (ret)
1326 goto out;
1327
1328 ret = -ENOMEM;
1329 if (count >= PAGE_SIZE)
1330 goto out;
1331
1332 /* No partial writes. */
1333 ret = -EINVAL;
1334 if (*ppos != 0)
1335 goto out;
1336
1337 ret = -ENOMEM;
1338 page = (char *)get_zeroed_page(GFP_KERNEL);
1339 if (!page)
1340 goto out;
1341
1342 ret = -EFAULT;
1343 if (copy_from_user(page, buf, count))
1344 goto out;
1345
1346 ret = -EINVAL;
1347 if (sscanf(page, "%u", &new_value) != 1)
1348 goto out;
1349
1350 avc_cache_threshold = new_value;
1351
1352 ret = count;
1353 out:
1354 free_page((unsigned long)page);
1355 return ret;
1356 }
1357
sel_read_avc_hash_stats(struct file * filp,char __user * buf,size_t count,loff_t * ppos)1358 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1359 size_t count, loff_t *ppos)
1360 {
1361 char *page;
1362 ssize_t length;
1363
1364 page = (char *)__get_free_page(GFP_KERNEL);
1365 if (!page)
1366 return -ENOMEM;
1367
1368 length = avc_get_hash_stats(page);
1369 if (length >= 0)
1370 length = simple_read_from_buffer(buf, count, ppos, page, length);
1371 free_page((unsigned long)page);
1372
1373 return length;
1374 }
1375
1376 static const struct file_operations sel_avc_cache_threshold_ops = {
1377 .read = sel_read_avc_cache_threshold,
1378 .write = sel_write_avc_cache_threshold,
1379 .llseek = generic_file_llseek,
1380 };
1381
1382 static const struct file_operations sel_avc_hash_stats_ops = {
1383 .read = sel_read_avc_hash_stats,
1384 .llseek = generic_file_llseek,
1385 };
1386
1387 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
sel_avc_get_stat_idx(loff_t * idx)1388 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1389 {
1390 int cpu;
1391
1392 for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1393 if (!cpu_possible(cpu))
1394 continue;
1395 *idx = cpu + 1;
1396 return &per_cpu(avc_cache_stats, cpu);
1397 }
1398 return NULL;
1399 }
1400
sel_avc_stats_seq_start(struct seq_file * seq,loff_t * pos)1401 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1402 {
1403 loff_t n = *pos - 1;
1404
1405 if (*pos == 0)
1406 return SEQ_START_TOKEN;
1407
1408 return sel_avc_get_stat_idx(&n);
1409 }
1410
sel_avc_stats_seq_next(struct seq_file * seq,void * v,loff_t * pos)1411 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1412 {
1413 return sel_avc_get_stat_idx(pos);
1414 }
1415
sel_avc_stats_seq_show(struct seq_file * seq,void * v)1416 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1417 {
1418 struct avc_cache_stats *st = v;
1419
1420 if (v == SEQ_START_TOKEN)
1421 seq_printf(seq, "lookups hits misses allocations reclaims "
1422 "frees\n");
1423 else {
1424 unsigned int lookups = st->lookups;
1425 unsigned int misses = st->misses;
1426 unsigned int hits = lookups - misses;
1427 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1428 hits, misses, st->allocations,
1429 st->reclaims, st->frees);
1430 }
1431 return 0;
1432 }
1433
sel_avc_stats_seq_stop(struct seq_file * seq,void * v)1434 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1435 { }
1436
1437 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1438 .start = sel_avc_stats_seq_start,
1439 .next = sel_avc_stats_seq_next,
1440 .show = sel_avc_stats_seq_show,
1441 .stop = sel_avc_stats_seq_stop,
1442 };
1443
sel_open_avc_cache_stats(struct inode * inode,struct file * file)1444 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1445 {
1446 return seq_open(file, &sel_avc_cache_stats_seq_ops);
1447 }
1448
1449 static const struct file_operations sel_avc_cache_stats_ops = {
1450 .open = sel_open_avc_cache_stats,
1451 .read = seq_read,
1452 .llseek = seq_lseek,
1453 .release = seq_release,
1454 };
1455 #endif
1456
sel_make_avc_files(struct dentry * dir)1457 static int sel_make_avc_files(struct dentry *dir)
1458 {
1459 int i;
1460 static struct tree_descr files[] = {
1461 { "cache_threshold",
1462 &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1463 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1464 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1465 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1466 #endif
1467 };
1468
1469 for (i = 0; i < ARRAY_SIZE(files); i++) {
1470 struct inode *inode;
1471 struct dentry *dentry;
1472
1473 dentry = d_alloc_name(dir, files[i].name);
1474 if (!dentry)
1475 return -ENOMEM;
1476
1477 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1478 if (!inode)
1479 return -ENOMEM;
1480
1481 inode->i_fop = files[i].ops;
1482 inode->i_ino = ++sel_last_ino;
1483 d_add(dentry, inode);
1484 }
1485
1486 return 0;
1487 }
1488
sel_read_initcon(struct file * file,char __user * buf,size_t count,loff_t * ppos)1489 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1490 size_t count, loff_t *ppos)
1491 {
1492 struct inode *inode;
1493 char *con;
1494 u32 sid, len;
1495 ssize_t ret;
1496
1497 inode = file->f_path.dentry->d_inode;
1498 sid = inode->i_ino&SEL_INO_MASK;
1499 ret = security_sid_to_context(sid, &con, &len);
1500 if (ret)
1501 return ret;
1502
1503 ret = simple_read_from_buffer(buf, count, ppos, con, len);
1504 kfree(con);
1505 return ret;
1506 }
1507
1508 static const struct file_operations sel_initcon_ops = {
1509 .read = sel_read_initcon,
1510 .llseek = generic_file_llseek,
1511 };
1512
sel_make_initcon_files(struct dentry * dir)1513 static int sel_make_initcon_files(struct dentry *dir)
1514 {
1515 int i;
1516
1517 for (i = 1; i <= SECINITSID_NUM; i++) {
1518 struct inode *inode;
1519 struct dentry *dentry;
1520 dentry = d_alloc_name(dir, security_get_initial_sid_context(i));
1521 if (!dentry)
1522 return -ENOMEM;
1523
1524 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1525 if (!inode)
1526 return -ENOMEM;
1527
1528 inode->i_fop = &sel_initcon_ops;
1529 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1530 d_add(dentry, inode);
1531 }
1532
1533 return 0;
1534 }
1535
sel_div(unsigned long a,unsigned long b)1536 static inline unsigned int sel_div(unsigned long a, unsigned long b)
1537 {
1538 return a / b - (a % b < 0);
1539 }
1540
sel_class_to_ino(u16 class)1541 static inline unsigned long sel_class_to_ino(u16 class)
1542 {
1543 return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1544 }
1545
sel_ino_to_class(unsigned long ino)1546 static inline u16 sel_ino_to_class(unsigned long ino)
1547 {
1548 return sel_div(ino & SEL_INO_MASK, SEL_VEC_MAX + 1);
1549 }
1550
sel_perm_to_ino(u16 class,u32 perm)1551 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1552 {
1553 return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1554 }
1555
sel_ino_to_perm(unsigned long ino)1556 static inline u32 sel_ino_to_perm(unsigned long ino)
1557 {
1558 return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1559 }
1560
sel_read_class(struct file * file,char __user * buf,size_t count,loff_t * ppos)1561 static ssize_t sel_read_class(struct file *file, char __user *buf,
1562 size_t count, loff_t *ppos)
1563 {
1564 ssize_t rc, len;
1565 char *page;
1566 unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1567
1568 page = (char *)__get_free_page(GFP_KERNEL);
1569 if (!page)
1570 return -ENOMEM;
1571
1572 len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_class(ino));
1573 rc = simple_read_from_buffer(buf, count, ppos, page, len);
1574 free_page((unsigned long)page);
1575
1576 return rc;
1577 }
1578
1579 static const struct file_operations sel_class_ops = {
1580 .read = sel_read_class,
1581 .llseek = generic_file_llseek,
1582 };
1583
sel_read_perm(struct file * file,char __user * buf,size_t count,loff_t * ppos)1584 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1585 size_t count, loff_t *ppos)
1586 {
1587 ssize_t rc, len;
1588 char *page;
1589 unsigned long ino = file->f_path.dentry->d_inode->i_ino;
1590
1591 page = (char *)__get_free_page(GFP_KERNEL);
1592 if (!page)
1593 return -ENOMEM;
1594
1595 len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_perm(ino));
1596 rc = simple_read_from_buffer(buf, count, ppos, page, len);
1597 free_page((unsigned long)page);
1598
1599 return rc;
1600 }
1601
1602 static const struct file_operations sel_perm_ops = {
1603 .read = sel_read_perm,
1604 .llseek = generic_file_llseek,
1605 };
1606
sel_read_policycap(struct file * file,char __user * buf,size_t count,loff_t * ppos)1607 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1608 size_t count, loff_t *ppos)
1609 {
1610 int value;
1611 char tmpbuf[TMPBUFLEN];
1612 ssize_t length;
1613 unsigned long i_ino = file->f_path.dentry->d_inode->i_ino;
1614
1615 value = security_policycap_supported(i_ino & SEL_INO_MASK);
1616 length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1617
1618 return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1619 }
1620
1621 static const struct file_operations sel_policycap_ops = {
1622 .read = sel_read_policycap,
1623 .llseek = generic_file_llseek,
1624 };
1625
sel_make_perm_files(char * objclass,int classvalue,struct dentry * dir)1626 static int sel_make_perm_files(char *objclass, int classvalue,
1627 struct dentry *dir)
1628 {
1629 int i, rc, nperms;
1630 char **perms;
1631
1632 rc = security_get_permissions(objclass, &perms, &nperms);
1633 if (rc)
1634 return rc;
1635
1636 for (i = 0; i < nperms; i++) {
1637 struct inode *inode;
1638 struct dentry *dentry;
1639
1640 rc = -ENOMEM;
1641 dentry = d_alloc_name(dir, perms[i]);
1642 if (!dentry)
1643 goto out;
1644
1645 rc = -ENOMEM;
1646 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1647 if (!inode)
1648 goto out;
1649
1650 inode->i_fop = &sel_perm_ops;
1651 /* i+1 since perm values are 1-indexed */
1652 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1653 d_add(dentry, inode);
1654 }
1655 rc = 0;
1656 out:
1657 for (i = 0; i < nperms; i++)
1658 kfree(perms[i]);
1659 kfree(perms);
1660 return rc;
1661 }
1662
sel_make_class_dir_entries(char * classname,int index,struct dentry * dir)1663 static int sel_make_class_dir_entries(char *classname, int index,
1664 struct dentry *dir)
1665 {
1666 struct dentry *dentry = NULL;
1667 struct inode *inode = NULL;
1668 int rc;
1669
1670 dentry = d_alloc_name(dir, "index");
1671 if (!dentry)
1672 return -ENOMEM;
1673
1674 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1675 if (!inode)
1676 return -ENOMEM;
1677
1678 inode->i_fop = &sel_class_ops;
1679 inode->i_ino = sel_class_to_ino(index);
1680 d_add(dentry, inode);
1681
1682 dentry = sel_make_dir(dir, "perms", &last_class_ino);
1683 if (IS_ERR(dentry))
1684 return PTR_ERR(dentry);
1685
1686 rc = sel_make_perm_files(classname, index, dentry);
1687
1688 return rc;
1689 }
1690
sel_remove_classes(void)1691 static void sel_remove_classes(void)
1692 {
1693 struct list_head *class_node;
1694
1695 list_for_each(class_node, &class_dir->d_subdirs) {
1696 struct dentry *class_subdir = list_entry(class_node,
1697 struct dentry, d_u.d_child);
1698 struct list_head *class_subdir_node;
1699
1700 list_for_each(class_subdir_node, &class_subdir->d_subdirs) {
1701 struct dentry *d = list_entry(class_subdir_node,
1702 struct dentry, d_u.d_child);
1703
1704 if (d->d_inode)
1705 if (d->d_inode->i_mode & S_IFDIR)
1706 sel_remove_entries(d);
1707 }
1708
1709 sel_remove_entries(class_subdir);
1710 }
1711
1712 sel_remove_entries(class_dir);
1713 }
1714
sel_make_classes(void)1715 static int sel_make_classes(void)
1716 {
1717 int rc, nclasses, i;
1718 char **classes;
1719
1720 /* delete any existing entries */
1721 sel_remove_classes();
1722
1723 rc = security_get_classes(&classes, &nclasses);
1724 if (rc)
1725 return rc;
1726
1727 /* +2 since classes are 1-indexed */
1728 last_class_ino = sel_class_to_ino(nclasses + 2);
1729
1730 for (i = 0; i < nclasses; i++) {
1731 struct dentry *class_name_dir;
1732
1733 class_name_dir = sel_make_dir(class_dir, classes[i],
1734 &last_class_ino);
1735 if (IS_ERR(class_name_dir)) {
1736 rc = PTR_ERR(class_name_dir);
1737 goto out;
1738 }
1739
1740 /* i+1 since class values are 1-indexed */
1741 rc = sel_make_class_dir_entries(classes[i], i + 1,
1742 class_name_dir);
1743 if (rc)
1744 goto out;
1745 }
1746 rc = 0;
1747 out:
1748 for (i = 0; i < nclasses; i++)
1749 kfree(classes[i]);
1750 kfree(classes);
1751 return rc;
1752 }
1753
sel_make_policycap(void)1754 static int sel_make_policycap(void)
1755 {
1756 unsigned int iter;
1757 struct dentry *dentry = NULL;
1758 struct inode *inode = NULL;
1759
1760 sel_remove_entries(policycap_dir);
1761
1762 for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1763 if (iter < ARRAY_SIZE(policycap_names))
1764 dentry = d_alloc_name(policycap_dir,
1765 policycap_names[iter]);
1766 else
1767 dentry = d_alloc_name(policycap_dir, "unknown");
1768
1769 if (dentry == NULL)
1770 return -ENOMEM;
1771
1772 inode = sel_make_inode(policycap_dir->d_sb, S_IFREG | S_IRUGO);
1773 if (inode == NULL)
1774 return -ENOMEM;
1775
1776 inode->i_fop = &sel_policycap_ops;
1777 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1778 d_add(dentry, inode);
1779 }
1780
1781 return 0;
1782 }
1783
sel_make_dir(struct dentry * dir,const char * name,unsigned long * ino)1784 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1785 unsigned long *ino)
1786 {
1787 struct dentry *dentry = d_alloc_name(dir, name);
1788 struct inode *inode;
1789
1790 if (!dentry)
1791 return ERR_PTR(-ENOMEM);
1792
1793 inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1794 if (!inode) {
1795 dput(dentry);
1796 return ERR_PTR(-ENOMEM);
1797 }
1798
1799 inode->i_op = &simple_dir_inode_operations;
1800 inode->i_fop = &simple_dir_operations;
1801 inode->i_ino = ++(*ino);
1802 /* directory inodes start off with i_nlink == 2 (for "." entry) */
1803 inc_nlink(inode);
1804 d_add(dentry, inode);
1805 /* bump link count on parent directory, too */
1806 inc_nlink(dir->d_inode);
1807
1808 return dentry;
1809 }
1810
sel_fill_super(struct super_block * sb,void * data,int silent)1811 static int sel_fill_super(struct super_block *sb, void *data, int silent)
1812 {
1813 int ret;
1814 struct dentry *dentry;
1815 struct inode *inode;
1816 struct inode_security_struct *isec;
1817
1818 static struct tree_descr selinux_files[] = {
1819 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1820 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1821 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1822 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1823 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1824 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1825 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1826 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1827 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1828 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1829 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1830 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1831 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1832 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1833 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1834 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1835 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUSR},
1836 /* last one */ {""}
1837 };
1838 ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
1839 if (ret)
1840 goto err;
1841
1842 bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &sel_last_ino);
1843 if (IS_ERR(bool_dir)) {
1844 ret = PTR_ERR(bool_dir);
1845 bool_dir = NULL;
1846 goto err;
1847 }
1848
1849 ret = -ENOMEM;
1850 dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
1851 if (!dentry)
1852 goto err;
1853
1854 ret = -ENOMEM;
1855 inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
1856 if (!inode)
1857 goto err;
1858
1859 inode->i_ino = ++sel_last_ino;
1860 isec = (struct inode_security_struct *)inode->i_security;
1861 isec->sid = SECINITSID_DEVNULL;
1862 isec->sclass = SECCLASS_CHR_FILE;
1863 isec->initialized = 1;
1864
1865 init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
1866 d_add(dentry, inode);
1867 selinux_null = dentry;
1868
1869 dentry = sel_make_dir(sb->s_root, "avc", &sel_last_ino);
1870 if (IS_ERR(dentry)) {
1871 ret = PTR_ERR(dentry);
1872 goto err;
1873 }
1874
1875 ret = sel_make_avc_files(dentry);
1876 if (ret)
1877 goto err;
1878
1879 dentry = sel_make_dir(sb->s_root, "initial_contexts", &sel_last_ino);
1880 if (IS_ERR(dentry)) {
1881 ret = PTR_ERR(dentry);
1882 goto err;
1883 }
1884
1885 ret = sel_make_initcon_files(dentry);
1886 if (ret)
1887 goto err;
1888
1889 class_dir = sel_make_dir(sb->s_root, "class", &sel_last_ino);
1890 if (IS_ERR(class_dir)) {
1891 ret = PTR_ERR(class_dir);
1892 class_dir = NULL;
1893 goto err;
1894 }
1895
1896 policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities", &sel_last_ino);
1897 if (IS_ERR(policycap_dir)) {
1898 ret = PTR_ERR(policycap_dir);
1899 policycap_dir = NULL;
1900 goto err;
1901 }
1902 return 0;
1903 err:
1904 printk(KERN_ERR "SELinux: %s: failed while creating inodes\n",
1905 __func__);
1906 return ret;
1907 }
1908
sel_mount(struct file_system_type * fs_type,int flags,const char * dev_name,void * data)1909 static struct dentry *sel_mount(struct file_system_type *fs_type,
1910 int flags, const char *dev_name, void *data)
1911 {
1912 return mount_single(fs_type, flags, data, sel_fill_super);
1913 }
1914
1915 static struct file_system_type sel_fs_type = {
1916 .name = "selinuxfs",
1917 .mount = sel_mount,
1918 .kill_sb = kill_litter_super,
1919 };
1920
1921 struct vfsmount *selinuxfs_mount;
1922 static struct kobject *selinuxfs_kobj;
1923
init_sel_fs(void)1924 static int __init init_sel_fs(void)
1925 {
1926 int err;
1927
1928 if (!selinux_enabled)
1929 return 0;
1930
1931 selinuxfs_kobj = kobject_create_and_add("selinux", fs_kobj);
1932 if (!selinuxfs_kobj)
1933 return -ENOMEM;
1934
1935 err = register_filesystem(&sel_fs_type);
1936 if (err) {
1937 kobject_put(selinuxfs_kobj);
1938 return err;
1939 }
1940
1941 selinuxfs_mount = kern_mount(&sel_fs_type);
1942 if (IS_ERR(selinuxfs_mount)) {
1943 printk(KERN_ERR "selinuxfs: could not mount!\n");
1944 err = PTR_ERR(selinuxfs_mount);
1945 selinuxfs_mount = NULL;
1946 }
1947
1948 return err;
1949 }
1950
1951 __initcall(init_sel_fs);
1952
1953 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
exit_sel_fs(void)1954 void exit_sel_fs(void)
1955 {
1956 kobject_put(selinuxfs_kobj);
1957 kern_unmount(selinuxfs_mount);
1958 unregister_filesystem(&sel_fs_type);
1959 }
1960 #endif
1961