Linux 5.9-rc6
[sfrench/cifs-2.6.git] / security / selinux / selinuxfs.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Updated: Karl MacMillan <kmacmillan@tresys.com>
3  *
4  *      Added conditional policy language extensions
5  *
6  *  Updated: Hewlett-Packard <paul@paul-moore.com>
7  *
8  *      Added support for the policy capability bitmap
9  *
10  * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
11  * Copyright (C) 2003 - 2004 Tresys Technology, LLC
12  * Copyright (C) 2004 Red Hat, Inc., James Morris <jmorris@redhat.com>
13  */
14
15 #include <linux/kernel.h>
16 #include <linux/pagemap.h>
17 #include <linux/slab.h>
18 #include <linux/vmalloc.h>
19 #include <linux/fs.h>
20 #include <linux/fs_context.h>
21 #include <linux/mount.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 enum sel_inos {
45         SEL_ROOT_INO = 2,
46         SEL_LOAD,       /* load policy */
47         SEL_ENFORCE,    /* get or set enforcing status */
48         SEL_CONTEXT,    /* validate context */
49         SEL_ACCESS,     /* compute access decision */
50         SEL_CREATE,     /* compute create labeling decision */
51         SEL_RELABEL,    /* compute relabeling decision */
52         SEL_USER,       /* compute reachable user contexts */
53         SEL_POLICYVERS, /* return policy version for this kernel */
54         SEL_COMMIT_BOOLS, /* commit new boolean values */
55         SEL_MLS,        /* return if MLS policy is enabled */
56         SEL_DISABLE,    /* disable SELinux until next reboot */
57         SEL_MEMBER,     /* compute polyinstantiation membership decision */
58         SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
59         SEL_COMPAT_NET, /* whether to use old compat network packet controls */
60         SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
61         SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
62         SEL_STATUS,     /* export current status using mmap() */
63         SEL_POLICY,     /* allow userspace to read the in kernel policy */
64         SEL_VALIDATE_TRANS, /* compute validatetrans decision */
65         SEL_INO_NEXT,   /* The next inode number to use */
66 };
67
68 struct selinux_fs_info {
69         struct dentry *bool_dir;
70         unsigned int bool_num;
71         char **bool_pending_names;
72         unsigned int *bool_pending_values;
73         struct dentry *class_dir;
74         unsigned long last_class_ino;
75         bool policy_opened;
76         struct dentry *policycap_dir;
77         struct mutex mutex;
78         unsigned long last_ino;
79         struct selinux_state *state;
80         struct super_block *sb;
81 };
82
83 static int selinux_fs_info_create(struct super_block *sb)
84 {
85         struct selinux_fs_info *fsi;
86
87         fsi = kzalloc(sizeof(*fsi), GFP_KERNEL);
88         if (!fsi)
89                 return -ENOMEM;
90
91         mutex_init(&fsi->mutex);
92         fsi->last_ino = SEL_INO_NEXT - 1;
93         fsi->state = &selinux_state;
94         fsi->sb = sb;
95         sb->s_fs_info = fsi;
96         return 0;
97 }
98
99 static void selinux_fs_info_free(struct super_block *sb)
100 {
101         struct selinux_fs_info *fsi = sb->s_fs_info;
102         int i;
103
104         if (fsi) {
105                 for (i = 0; i < fsi->bool_num; i++)
106                         kfree(fsi->bool_pending_names[i]);
107                 kfree(fsi->bool_pending_names);
108                 kfree(fsi->bool_pending_values);
109         }
110         kfree(sb->s_fs_info);
111         sb->s_fs_info = NULL;
112 }
113
114 #define SEL_INITCON_INO_OFFSET          0x01000000
115 #define SEL_BOOL_INO_OFFSET             0x02000000
116 #define SEL_CLASS_INO_OFFSET            0x04000000
117 #define SEL_POLICYCAP_INO_OFFSET        0x08000000
118 #define SEL_INO_MASK                    0x00ffffff
119
120 #define TMPBUFLEN       12
121 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
122                                 size_t count, loff_t *ppos)
123 {
124         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
125         char tmpbuf[TMPBUFLEN];
126         ssize_t length;
127
128         length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
129                            enforcing_enabled(fsi->state));
130         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
131 }
132
133 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
134 static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
135                                  size_t count, loff_t *ppos)
136
137 {
138         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
139         struct selinux_state *state = fsi->state;
140         char *page = NULL;
141         ssize_t length;
142         int old_value, new_value;
143
144         if (count >= PAGE_SIZE)
145                 return -ENOMEM;
146
147         /* No partial writes. */
148         if (*ppos != 0)
149                 return -EINVAL;
150
151         page = memdup_user_nul(buf, count);
152         if (IS_ERR(page))
153                 return PTR_ERR(page);
154
155         length = -EINVAL;
156         if (sscanf(page, "%d", &new_value) != 1)
157                 goto out;
158
159         new_value = !!new_value;
160
161         old_value = enforcing_enabled(state);
162         if (new_value != old_value) {
163                 length = avc_has_perm(&selinux_state,
164                                       current_sid(), SECINITSID_SECURITY,
165                                       SECCLASS_SECURITY, SECURITY__SETENFORCE,
166                                       NULL);
167                 if (length)
168                         goto out;
169                 audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS,
170                         "enforcing=%d old_enforcing=%d auid=%u ses=%u"
171                         " enabled=1 old-enabled=1 lsm=selinux res=1",
172                         new_value, old_value,
173                         from_kuid(&init_user_ns, audit_get_loginuid(current)),
174                         audit_get_sessionid(current));
175                 enforcing_set(state, new_value);
176                 if (new_value)
177                         avc_ss_reset(state->avc, 0);
178                 selnl_notify_setenforce(new_value);
179                 selinux_status_update_setenforce(state, new_value);
180                 if (!new_value)
181                         call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL);
182         }
183         length = count;
184 out:
185         kfree(page);
186         return length;
187 }
188 #else
189 #define sel_write_enforce NULL
190 #endif
191
192 static const struct file_operations sel_enforce_ops = {
193         .read           = sel_read_enforce,
194         .write          = sel_write_enforce,
195         .llseek         = generic_file_llseek,
196 };
197
198 static ssize_t sel_read_handle_unknown(struct file *filp, char __user *buf,
199                                         size_t count, loff_t *ppos)
200 {
201         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
202         struct selinux_state *state = fsi->state;
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(state) :
208                 !security_get_allow_unknown(state);
209
210         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
211         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
212 }
213
214 static const struct file_operations sel_handle_unknown_ops = {
215         .read           = sel_read_handle_unknown,
216         .llseek         = generic_file_llseek,
217 };
218
219 static int sel_open_handle_status(struct inode *inode, struct file *filp)
220 {
221         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
222         struct page    *status = selinux_kernel_status_page(fsi->state);
223
224         if (!status)
225                 return -ENOMEM;
226
227         filp->private_data = status;
228
229         return 0;
230 }
231
232 static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
233                                       size_t count, loff_t *ppos)
234 {
235         struct page    *status = filp->private_data;
236
237         BUG_ON(!status);
238
239         return simple_read_from_buffer(buf, count, ppos,
240                                        page_address(status),
241                                        sizeof(struct selinux_kernel_status));
242 }
243
244 static int sel_mmap_handle_status(struct file *filp,
245                                   struct vm_area_struct *vma)
246 {
247         struct page    *status = filp->private_data;
248         unsigned long   size = vma->vm_end - vma->vm_start;
249
250         BUG_ON(!status);
251
252         /* only allows one page from the head */
253         if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
254                 return -EIO;
255         /* disallow writable mapping */
256         if (vma->vm_flags & VM_WRITE)
257                 return -EPERM;
258         /* disallow mprotect() turns it into writable */
259         vma->vm_flags &= ~VM_MAYWRITE;
260
261         return remap_pfn_range(vma, vma->vm_start,
262                                page_to_pfn(status),
263                                size, vma->vm_page_prot);
264 }
265
266 static const struct file_operations sel_handle_status_ops = {
267         .open           = sel_open_handle_status,
268         .read           = sel_read_handle_status,
269         .mmap           = sel_mmap_handle_status,
270         .llseek         = generic_file_llseek,
271 };
272
273 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
274 static ssize_t sel_write_disable(struct file *file, const char __user *buf,
275                                  size_t count, loff_t *ppos)
276
277 {
278         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
279         char *page;
280         ssize_t length;
281         int new_value;
282         int enforcing;
283
284         /* NOTE: we are now officially considering runtime disable as
285          *       deprecated, and using it will become increasingly painful
286          *       (e.g. sleeping/blocking) as we progress through future
287          *       kernel releases until eventually it is removed
288          */
289         pr_err("SELinux:  Runtime disable is deprecated, use selinux=0 on the kernel cmdline.\n");
290
291         if (count >= PAGE_SIZE)
292                 return -ENOMEM;
293
294         /* No partial writes. */
295         if (*ppos != 0)
296                 return -EINVAL;
297
298         page = memdup_user_nul(buf, count);
299         if (IS_ERR(page))
300                 return PTR_ERR(page);
301
302         length = -EINVAL;
303         if (sscanf(page, "%d", &new_value) != 1)
304                 goto out;
305
306         if (new_value) {
307                 enforcing = enforcing_enabled(fsi->state);
308                 length = selinux_disable(fsi->state);
309                 if (length)
310                         goto out;
311                 audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS,
312                         "enforcing=%d old_enforcing=%d auid=%u ses=%u"
313                         " enabled=0 old-enabled=1 lsm=selinux res=1",
314                         enforcing, enforcing,
315                         from_kuid(&init_user_ns, audit_get_loginuid(current)),
316                         audit_get_sessionid(current));
317         }
318
319         length = count;
320 out:
321         kfree(page);
322         return length;
323 }
324 #else
325 #define sel_write_disable NULL
326 #endif
327
328 static const struct file_operations sel_disable_ops = {
329         .write          = sel_write_disable,
330         .llseek         = generic_file_llseek,
331 };
332
333 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
334                                    size_t count, loff_t *ppos)
335 {
336         char tmpbuf[TMPBUFLEN];
337         ssize_t length;
338
339         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
340         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
341 }
342
343 static const struct file_operations sel_policyvers_ops = {
344         .read           = sel_read_policyvers,
345         .llseek         = generic_file_llseek,
346 };
347
348 /* declaration for sel_write_load */
349 static int sel_make_bools(struct selinux_fs_info *fsi);
350 static int sel_make_classes(struct selinux_fs_info *fsi);
351 static int sel_make_policycap(struct selinux_fs_info *fsi);
352
353 /* declaration for sel_make_class_dirs */
354 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
355                         unsigned long *ino);
356
357 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
358                                 size_t count, loff_t *ppos)
359 {
360         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
361         char tmpbuf[TMPBUFLEN];
362         ssize_t length;
363
364         length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
365                            security_mls_enabled(fsi->state));
366         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
367 }
368
369 static const struct file_operations sel_mls_ops = {
370         .read           = sel_read_mls,
371         .llseek         = generic_file_llseek,
372 };
373
374 struct policy_load_memory {
375         size_t len;
376         void *data;
377 };
378
379 static int sel_open_policy(struct inode *inode, struct file *filp)
380 {
381         struct selinux_fs_info *fsi = inode->i_sb->s_fs_info;
382         struct selinux_state *state = fsi->state;
383         struct policy_load_memory *plm = NULL;
384         int rc;
385
386         BUG_ON(filp->private_data);
387
388         mutex_lock(&fsi->mutex);
389
390         rc = avc_has_perm(&selinux_state,
391                           current_sid(), SECINITSID_SECURITY,
392                           SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL);
393         if (rc)
394                 goto err;
395
396         rc = -EBUSY;
397         if (fsi->policy_opened)
398                 goto err;
399
400         rc = -ENOMEM;
401         plm = kzalloc(sizeof(*plm), GFP_KERNEL);
402         if (!plm)
403                 goto err;
404
405         if (i_size_read(inode) != security_policydb_len(state)) {
406                 inode_lock(inode);
407                 i_size_write(inode, security_policydb_len(state));
408                 inode_unlock(inode);
409         }
410
411         rc = security_read_policy(state, &plm->data, &plm->len);
412         if (rc)
413                 goto err;
414
415         fsi->policy_opened = 1;
416
417         filp->private_data = plm;
418
419         mutex_unlock(&fsi->mutex);
420
421         return 0;
422 err:
423         mutex_unlock(&fsi->mutex);
424
425         if (plm)
426                 vfree(plm->data);
427         kfree(plm);
428         return rc;
429 }
430
431 static int sel_release_policy(struct inode *inode, struct file *filp)
432 {
433         struct selinux_fs_info *fsi = inode->i_sb->s_fs_info;
434         struct policy_load_memory *plm = filp->private_data;
435
436         BUG_ON(!plm);
437
438         fsi->policy_opened = 0;
439
440         vfree(plm->data);
441         kfree(plm);
442
443         return 0;
444 }
445
446 static ssize_t sel_read_policy(struct file *filp, char __user *buf,
447                                size_t count, loff_t *ppos)
448 {
449         struct policy_load_memory *plm = filp->private_data;
450         int ret;
451
452         ret = avc_has_perm(&selinux_state,
453                            current_sid(), SECINITSID_SECURITY,
454                           SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL);
455         if (ret)
456                 return ret;
457
458         return simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
459 }
460
461 static vm_fault_t sel_mmap_policy_fault(struct vm_fault *vmf)
462 {
463         struct policy_load_memory *plm = vmf->vma->vm_file->private_data;
464         unsigned long offset;
465         struct page *page;
466
467         if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
468                 return VM_FAULT_SIGBUS;
469
470         offset = vmf->pgoff << PAGE_SHIFT;
471         if (offset >= roundup(plm->len, PAGE_SIZE))
472                 return VM_FAULT_SIGBUS;
473
474         page = vmalloc_to_page(plm->data + offset);
475         get_page(page);
476
477         vmf->page = page;
478
479         return 0;
480 }
481
482 static const struct vm_operations_struct sel_mmap_policy_ops = {
483         .fault = sel_mmap_policy_fault,
484         .page_mkwrite = sel_mmap_policy_fault,
485 };
486
487 static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
488 {
489         if (vma->vm_flags & VM_SHARED) {
490                 /* do not allow mprotect to make mapping writable */
491                 vma->vm_flags &= ~VM_MAYWRITE;
492
493                 if (vma->vm_flags & VM_WRITE)
494                         return -EACCES;
495         }
496
497         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
498         vma->vm_ops = &sel_mmap_policy_ops;
499
500         return 0;
501 }
502
503 static const struct file_operations sel_policy_ops = {
504         .open           = sel_open_policy,
505         .read           = sel_read_policy,
506         .mmap           = sel_mmap_policy,
507         .release        = sel_release_policy,
508         .llseek         = generic_file_llseek,
509 };
510
511 static int sel_make_policy_nodes(struct selinux_fs_info *fsi)
512 {
513         int ret;
514
515         ret = sel_make_bools(fsi);
516         if (ret) {
517                 pr_err("SELinux: failed to load policy booleans\n");
518                 return ret;
519         }
520
521         ret = sel_make_classes(fsi);
522         if (ret) {
523                 pr_err("SELinux: failed to load policy classes\n");
524                 return ret;
525         }
526
527         ret = sel_make_policycap(fsi);
528         if (ret) {
529                 pr_err("SELinux: failed to load policy capabilities\n");
530                 return ret;
531         }
532
533         return 0;
534 }
535
536 static ssize_t sel_write_load(struct file *file, const char __user *buf,
537                               size_t count, loff_t *ppos)
538
539 {
540         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
541         ssize_t length;
542         void *data = NULL;
543
544         mutex_lock(&fsi->mutex);
545
546         length = avc_has_perm(&selinux_state,
547                               current_sid(), SECINITSID_SECURITY,
548                               SECCLASS_SECURITY, SECURITY__LOAD_POLICY, NULL);
549         if (length)
550                 goto out;
551
552         /* No partial writes. */
553         length = -EINVAL;
554         if (*ppos != 0)
555                 goto out;
556
557         length = -ENOMEM;
558         data = vmalloc(count);
559         if (!data)
560                 goto out;
561
562         length = -EFAULT;
563         if (copy_from_user(data, buf, count) != 0)
564                 goto out;
565
566         length = security_load_policy(fsi->state, data, count);
567         if (length) {
568                 pr_warn_ratelimited("SELinux: failed to load policy\n");
569                 goto out;
570         }
571
572         length = sel_make_policy_nodes(fsi);
573         if (length)
574                 goto out1;
575
576         length = count;
577
578 out1:
579         audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
580                 "auid=%u ses=%u lsm=selinux res=1",
581                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
582                 audit_get_sessionid(current));
583 out:
584         mutex_unlock(&fsi->mutex);
585         vfree(data);
586         return length;
587 }
588
589 static const struct file_operations sel_load_ops = {
590         .write          = sel_write_load,
591         .llseek         = generic_file_llseek,
592 };
593
594 static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
595 {
596         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
597         struct selinux_state *state = fsi->state;
598         char *canon = NULL;
599         u32 sid, len;
600         ssize_t length;
601
602         length = avc_has_perm(&selinux_state,
603                               current_sid(), SECINITSID_SECURITY,
604                               SECCLASS_SECURITY, SECURITY__CHECK_CONTEXT, NULL);
605         if (length)
606                 goto out;
607
608         length = security_context_to_sid(state, buf, size, &sid, GFP_KERNEL);
609         if (length)
610                 goto out;
611
612         length = security_sid_to_context(state, sid, &canon, &len);
613         if (length)
614                 goto out;
615
616         length = -ERANGE;
617         if (len > SIMPLE_TRANSACTION_LIMIT) {
618                 pr_err("SELinux: %s:  context size (%u) exceeds "
619                         "payload max\n", __func__, len);
620                 goto out;
621         }
622
623         memcpy(buf, canon, len);
624         length = len;
625 out:
626         kfree(canon);
627         return length;
628 }
629
630 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
631                                      size_t count, loff_t *ppos)
632 {
633         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
634         char tmpbuf[TMPBUFLEN];
635         ssize_t length;
636
637         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", fsi->state->checkreqprot);
638         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
639 }
640
641 static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
642                                       size_t count, loff_t *ppos)
643 {
644         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
645         char *page;
646         ssize_t length;
647         unsigned int new_value;
648
649         length = avc_has_perm(&selinux_state,
650                               current_sid(), SECINITSID_SECURITY,
651                               SECCLASS_SECURITY, SECURITY__SETCHECKREQPROT,
652                               NULL);
653         if (length)
654                 return length;
655
656         if (count >= PAGE_SIZE)
657                 return -ENOMEM;
658
659         /* No partial writes. */
660         if (*ppos != 0)
661                 return -EINVAL;
662
663         page = memdup_user_nul(buf, count);
664         if (IS_ERR(page))
665                 return PTR_ERR(page);
666
667         length = -EINVAL;
668         if (sscanf(page, "%u", &new_value) != 1)
669                 goto out;
670
671         if (new_value) {
672                 char comm[sizeof(current->comm)];
673
674                 memcpy(comm, current->comm, sizeof(comm));
675                 pr_warn_once("SELinux: %s (%d) set checkreqprot to 1. This is deprecated and will be rejected in a future kernel release.\n",
676                              comm, current->pid);
677         }
678
679         fsi->state->checkreqprot = new_value ? 1 : 0;
680         length = count;
681 out:
682         kfree(page);
683         return length;
684 }
685 static const struct file_operations sel_checkreqprot_ops = {
686         .read           = sel_read_checkreqprot,
687         .write          = sel_write_checkreqprot,
688         .llseek         = generic_file_llseek,
689 };
690
691 static ssize_t sel_write_validatetrans(struct file *file,
692                                         const char __user *buf,
693                                         size_t count, loff_t *ppos)
694 {
695         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
696         struct selinux_state *state = fsi->state;
697         char *oldcon = NULL, *newcon = NULL, *taskcon = NULL;
698         char *req = NULL;
699         u32 osid, nsid, tsid;
700         u16 tclass;
701         int rc;
702
703         rc = avc_has_perm(&selinux_state,
704                           current_sid(), SECINITSID_SECURITY,
705                           SECCLASS_SECURITY, SECURITY__VALIDATE_TRANS, NULL);
706         if (rc)
707                 goto out;
708
709         rc = -ENOMEM;
710         if (count >= PAGE_SIZE)
711                 goto out;
712
713         /* No partial writes. */
714         rc = -EINVAL;
715         if (*ppos != 0)
716                 goto out;
717
718         req = memdup_user_nul(buf, count);
719         if (IS_ERR(req)) {
720                 rc = PTR_ERR(req);
721                 req = NULL;
722                 goto out;
723         }
724
725         rc = -ENOMEM;
726         oldcon = kzalloc(count + 1, GFP_KERNEL);
727         if (!oldcon)
728                 goto out;
729
730         newcon = kzalloc(count + 1, GFP_KERNEL);
731         if (!newcon)
732                 goto out;
733
734         taskcon = kzalloc(count + 1, GFP_KERNEL);
735         if (!taskcon)
736                 goto out;
737
738         rc = -EINVAL;
739         if (sscanf(req, "%s %s %hu %s", oldcon, newcon, &tclass, taskcon) != 4)
740                 goto out;
741
742         rc = security_context_str_to_sid(state, oldcon, &osid, GFP_KERNEL);
743         if (rc)
744                 goto out;
745
746         rc = security_context_str_to_sid(state, newcon, &nsid, GFP_KERNEL);
747         if (rc)
748                 goto out;
749
750         rc = security_context_str_to_sid(state, taskcon, &tsid, GFP_KERNEL);
751         if (rc)
752                 goto out;
753
754         rc = security_validate_transition_user(state, osid, nsid, tsid, tclass);
755         if (!rc)
756                 rc = count;
757 out:
758         kfree(req);
759         kfree(oldcon);
760         kfree(newcon);
761         kfree(taskcon);
762         return rc;
763 }
764
765 static const struct file_operations sel_transition_ops = {
766         .write          = sel_write_validatetrans,
767         .llseek         = generic_file_llseek,
768 };
769
770 /*
771  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
772  */
773 static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
774 static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
775 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
776 static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
777 static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
778
779 static ssize_t (*const write_op[])(struct file *, char *, size_t) = {
780         [SEL_ACCESS] = sel_write_access,
781         [SEL_CREATE] = sel_write_create,
782         [SEL_RELABEL] = sel_write_relabel,
783         [SEL_USER] = sel_write_user,
784         [SEL_MEMBER] = sel_write_member,
785         [SEL_CONTEXT] = sel_write_context,
786 };
787
788 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
789 {
790         ino_t ino = file_inode(file)->i_ino;
791         char *data;
792         ssize_t rv;
793
794         if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
795                 return -EINVAL;
796
797         data = simple_transaction_get(file, buf, size);
798         if (IS_ERR(data))
799                 return PTR_ERR(data);
800
801         rv = write_op[ino](file, data, size);
802         if (rv > 0) {
803                 simple_transaction_set(file, rv);
804                 rv = size;
805         }
806         return rv;
807 }
808
809 static const struct file_operations transaction_ops = {
810         .write          = selinux_transaction_write,
811         .read           = simple_transaction_read,
812         .release        = simple_transaction_release,
813         .llseek         = generic_file_llseek,
814 };
815
816 /*
817  * payload - write methods
818  * If the method has a response, the response should be put in buf,
819  * and the length returned.  Otherwise return 0 or and -error.
820  */
821
822 static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
823 {
824         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
825         struct selinux_state *state = fsi->state;
826         char *scon = NULL, *tcon = NULL;
827         u32 ssid, tsid;
828         u16 tclass;
829         struct av_decision avd;
830         ssize_t length;
831
832         length = avc_has_perm(&selinux_state,
833                               current_sid(), SECINITSID_SECURITY,
834                               SECCLASS_SECURITY, SECURITY__COMPUTE_AV, NULL);
835         if (length)
836                 goto out;
837
838         length = -ENOMEM;
839         scon = kzalloc(size + 1, GFP_KERNEL);
840         if (!scon)
841                 goto out;
842
843         length = -ENOMEM;
844         tcon = kzalloc(size + 1, GFP_KERNEL);
845         if (!tcon)
846                 goto out;
847
848         length = -EINVAL;
849         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
850                 goto out;
851
852         length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL);
853         if (length)
854                 goto out;
855
856         length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL);
857         if (length)
858                 goto out;
859
860         security_compute_av_user(state, ssid, tsid, tclass, &avd);
861
862         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
863                           "%x %x %x %x %u %x",
864                           avd.allowed, 0xffffffff,
865                           avd.auditallow, avd.auditdeny,
866                           avd.seqno, avd.flags);
867 out:
868         kfree(tcon);
869         kfree(scon);
870         return length;
871 }
872
873 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
874 {
875         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
876         struct selinux_state *state = fsi->state;
877         char *scon = NULL, *tcon = NULL;
878         char *namebuf = NULL, *objname = NULL;
879         u32 ssid, tsid, newsid;
880         u16 tclass;
881         ssize_t length;
882         char *newcon = NULL;
883         u32 len;
884         int nargs;
885
886         length = avc_has_perm(&selinux_state,
887                               current_sid(), SECINITSID_SECURITY,
888                               SECCLASS_SECURITY, SECURITY__COMPUTE_CREATE,
889                               NULL);
890         if (length)
891                 goto out;
892
893         length = -ENOMEM;
894         scon = kzalloc(size + 1, GFP_KERNEL);
895         if (!scon)
896                 goto out;
897
898         length = -ENOMEM;
899         tcon = kzalloc(size + 1, GFP_KERNEL);
900         if (!tcon)
901                 goto out;
902
903         length = -ENOMEM;
904         namebuf = kzalloc(size + 1, GFP_KERNEL);
905         if (!namebuf)
906                 goto out;
907
908         length = -EINVAL;
909         nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
910         if (nargs < 3 || nargs > 4)
911                 goto out;
912         if (nargs == 4) {
913                 /*
914                  * If and when the name of new object to be queried contains
915                  * either whitespace or multibyte characters, they shall be
916                  * encoded based on the percentage-encoding rule.
917                  * If not encoded, the sscanf logic picks up only left-half
918                  * of the supplied name; splitted by a whitespace unexpectedly.
919                  */
920                 char   *r, *w;
921                 int     c1, c2;
922
923                 r = w = namebuf;
924                 do {
925                         c1 = *r++;
926                         if (c1 == '+')
927                                 c1 = ' ';
928                         else if (c1 == '%') {
929                                 c1 = hex_to_bin(*r++);
930                                 if (c1 < 0)
931                                         goto out;
932                                 c2 = hex_to_bin(*r++);
933                                 if (c2 < 0)
934                                         goto out;
935                                 c1 = (c1 << 4) | c2;
936                         }
937                         *w++ = c1;
938                 } while (c1 != '\0');
939
940                 objname = namebuf;
941         }
942
943         length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL);
944         if (length)
945                 goto out;
946
947         length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL);
948         if (length)
949                 goto out;
950
951         length = security_transition_sid_user(state, ssid, tsid, tclass,
952                                               objname, &newsid);
953         if (length)
954                 goto out;
955
956         length = security_sid_to_context(state, newsid, &newcon, &len);
957         if (length)
958                 goto out;
959
960         length = -ERANGE;
961         if (len > SIMPLE_TRANSACTION_LIMIT) {
962                 pr_err("SELinux: %s:  context size (%u) exceeds "
963                         "payload max\n", __func__, len);
964                 goto out;
965         }
966
967         memcpy(buf, newcon, len);
968         length = len;
969 out:
970         kfree(newcon);
971         kfree(namebuf);
972         kfree(tcon);
973         kfree(scon);
974         return length;
975 }
976
977 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
978 {
979         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
980         struct selinux_state *state = fsi->state;
981         char *scon = NULL, *tcon = NULL;
982         u32 ssid, tsid, newsid;
983         u16 tclass;
984         ssize_t length;
985         char *newcon = NULL;
986         u32 len;
987
988         length = avc_has_perm(&selinux_state,
989                               current_sid(), SECINITSID_SECURITY,
990                               SECCLASS_SECURITY, SECURITY__COMPUTE_RELABEL,
991                               NULL);
992         if (length)
993                 goto out;
994
995         length = -ENOMEM;
996         scon = kzalloc(size + 1, GFP_KERNEL);
997         if (!scon)
998                 goto out;
999
1000         length = -ENOMEM;
1001         tcon = kzalloc(size + 1, GFP_KERNEL);
1002         if (!tcon)
1003                 goto out;
1004
1005         length = -EINVAL;
1006         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
1007                 goto out;
1008
1009         length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL);
1010         if (length)
1011                 goto out;
1012
1013         length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL);
1014         if (length)
1015                 goto out;
1016
1017         length = security_change_sid(state, ssid, tsid, tclass, &newsid);
1018         if (length)
1019                 goto out;
1020
1021         length = security_sid_to_context(state, newsid, &newcon, &len);
1022         if (length)
1023                 goto out;
1024
1025         length = -ERANGE;
1026         if (len > SIMPLE_TRANSACTION_LIMIT)
1027                 goto out;
1028
1029         memcpy(buf, newcon, len);
1030         length = len;
1031 out:
1032         kfree(newcon);
1033         kfree(tcon);
1034         kfree(scon);
1035         return length;
1036 }
1037
1038 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
1039 {
1040         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1041         struct selinux_state *state = fsi->state;
1042         char *con = NULL, *user = NULL, *ptr;
1043         u32 sid, *sids = NULL;
1044         ssize_t length;
1045         char *newcon;
1046         int i, rc;
1047         u32 len, nsids;
1048
1049         length = avc_has_perm(&selinux_state,
1050                               current_sid(), SECINITSID_SECURITY,
1051                               SECCLASS_SECURITY, SECURITY__COMPUTE_USER,
1052                               NULL);
1053         if (length)
1054                 goto out;
1055
1056         length = -ENOMEM;
1057         con = kzalloc(size + 1, GFP_KERNEL);
1058         if (!con)
1059                 goto out;
1060
1061         length = -ENOMEM;
1062         user = kzalloc(size + 1, GFP_KERNEL);
1063         if (!user)
1064                 goto out;
1065
1066         length = -EINVAL;
1067         if (sscanf(buf, "%s %s", con, user) != 2)
1068                 goto out;
1069
1070         length = security_context_str_to_sid(state, con, &sid, GFP_KERNEL);
1071         if (length)
1072                 goto out;
1073
1074         length = security_get_user_sids(state, sid, user, &sids, &nsids);
1075         if (length)
1076                 goto out;
1077
1078         length = sprintf(buf, "%u", nsids) + 1;
1079         ptr = buf + length;
1080         for (i = 0; i < nsids; i++) {
1081                 rc = security_sid_to_context(state, sids[i], &newcon, &len);
1082                 if (rc) {
1083                         length = rc;
1084                         goto out;
1085                 }
1086                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
1087                         kfree(newcon);
1088                         length = -ERANGE;
1089                         goto out;
1090                 }
1091                 memcpy(ptr, newcon, len);
1092                 kfree(newcon);
1093                 ptr += len;
1094                 length += len;
1095         }
1096 out:
1097         kfree(sids);
1098         kfree(user);
1099         kfree(con);
1100         return length;
1101 }
1102
1103 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
1104 {
1105         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1106         struct selinux_state *state = fsi->state;
1107         char *scon = NULL, *tcon = NULL;
1108         u32 ssid, tsid, newsid;
1109         u16 tclass;
1110         ssize_t length;
1111         char *newcon = NULL;
1112         u32 len;
1113
1114         length = avc_has_perm(&selinux_state,
1115                               current_sid(), SECINITSID_SECURITY,
1116                               SECCLASS_SECURITY, SECURITY__COMPUTE_MEMBER,
1117                               NULL);
1118         if (length)
1119                 goto out;
1120
1121         length = -ENOMEM;
1122         scon = kzalloc(size + 1, GFP_KERNEL);
1123         if (!scon)
1124                 goto out;
1125
1126         length = -ENOMEM;
1127         tcon = kzalloc(size + 1, GFP_KERNEL);
1128         if (!tcon)
1129                 goto out;
1130
1131         length = -EINVAL;
1132         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
1133                 goto out;
1134
1135         length = security_context_str_to_sid(state, scon, &ssid, GFP_KERNEL);
1136         if (length)
1137                 goto out;
1138
1139         length = security_context_str_to_sid(state, tcon, &tsid, GFP_KERNEL);
1140         if (length)
1141                 goto out;
1142
1143         length = security_member_sid(state, ssid, tsid, tclass, &newsid);
1144         if (length)
1145                 goto out;
1146
1147         length = security_sid_to_context(state, newsid, &newcon, &len);
1148         if (length)
1149                 goto out;
1150
1151         length = -ERANGE;
1152         if (len > SIMPLE_TRANSACTION_LIMIT) {
1153                 pr_err("SELinux: %s:  context size (%u) exceeds "
1154                         "payload max\n", __func__, len);
1155                 goto out;
1156         }
1157
1158         memcpy(buf, newcon, len);
1159         length = len;
1160 out:
1161         kfree(newcon);
1162         kfree(tcon);
1163         kfree(scon);
1164         return length;
1165 }
1166
1167 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1168 {
1169         struct inode *ret = new_inode(sb);
1170
1171         if (ret) {
1172                 ret->i_mode = mode;
1173                 ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret);
1174         }
1175         return ret;
1176 }
1177
1178 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1179                              size_t count, loff_t *ppos)
1180 {
1181         struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1182         char *page = NULL;
1183         ssize_t length;
1184         ssize_t ret;
1185         int cur_enforcing;
1186         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1187         const char *name = filep->f_path.dentry->d_name.name;
1188
1189         mutex_lock(&fsi->mutex);
1190
1191         ret = -EINVAL;
1192         if (index >= fsi->bool_num || strcmp(name,
1193                                              fsi->bool_pending_names[index]))
1194                 goto out_unlock;
1195
1196         ret = -ENOMEM;
1197         page = (char *)get_zeroed_page(GFP_KERNEL);
1198         if (!page)
1199                 goto out_unlock;
1200
1201         cur_enforcing = security_get_bool_value(fsi->state, index);
1202         if (cur_enforcing < 0) {
1203                 ret = cur_enforcing;
1204                 goto out_unlock;
1205         }
1206         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1207                           fsi->bool_pending_values[index]);
1208         mutex_unlock(&fsi->mutex);
1209         ret = simple_read_from_buffer(buf, count, ppos, page, length);
1210 out_free:
1211         free_page((unsigned long)page);
1212         return ret;
1213
1214 out_unlock:
1215         mutex_unlock(&fsi->mutex);
1216         goto out_free;
1217 }
1218
1219 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1220                               size_t count, loff_t *ppos)
1221 {
1222         struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1223         char *page = NULL;
1224         ssize_t length;
1225         int new_value;
1226         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1227         const char *name = filep->f_path.dentry->d_name.name;
1228
1229         if (count >= PAGE_SIZE)
1230                 return -ENOMEM;
1231
1232         /* No partial writes. */
1233         if (*ppos != 0)
1234                 return -EINVAL;
1235
1236         page = memdup_user_nul(buf, count);
1237         if (IS_ERR(page))
1238                 return PTR_ERR(page);
1239
1240         mutex_lock(&fsi->mutex);
1241
1242         length = avc_has_perm(&selinux_state,
1243                               current_sid(), SECINITSID_SECURITY,
1244                               SECCLASS_SECURITY, SECURITY__SETBOOL,
1245                               NULL);
1246         if (length)
1247                 goto out;
1248
1249         length = -EINVAL;
1250         if (index >= fsi->bool_num || strcmp(name,
1251                                              fsi->bool_pending_names[index]))
1252                 goto out;
1253
1254         length = -EINVAL;
1255         if (sscanf(page, "%d", &new_value) != 1)
1256                 goto out;
1257
1258         if (new_value)
1259                 new_value = 1;
1260
1261         fsi->bool_pending_values[index] = new_value;
1262         length = count;
1263
1264 out:
1265         mutex_unlock(&fsi->mutex);
1266         kfree(page);
1267         return length;
1268 }
1269
1270 static const struct file_operations sel_bool_ops = {
1271         .read           = sel_read_bool,
1272         .write          = sel_write_bool,
1273         .llseek         = generic_file_llseek,
1274 };
1275
1276 static ssize_t sel_commit_bools_write(struct file *filep,
1277                                       const char __user *buf,
1278                                       size_t count, loff_t *ppos)
1279 {
1280         struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1281         char *page = NULL;
1282         ssize_t length;
1283         int new_value;
1284
1285         if (count >= PAGE_SIZE)
1286                 return -ENOMEM;
1287
1288         /* No partial writes. */
1289         if (*ppos != 0)
1290                 return -EINVAL;
1291
1292         page = memdup_user_nul(buf, count);
1293         if (IS_ERR(page))
1294                 return PTR_ERR(page);
1295
1296         mutex_lock(&fsi->mutex);
1297
1298         length = avc_has_perm(&selinux_state,
1299                               current_sid(), SECINITSID_SECURITY,
1300                               SECCLASS_SECURITY, SECURITY__SETBOOL,
1301                               NULL);
1302         if (length)
1303                 goto out;
1304
1305         length = -EINVAL;
1306         if (sscanf(page, "%d", &new_value) != 1)
1307                 goto out;
1308
1309         length = 0;
1310         if (new_value && fsi->bool_pending_values)
1311                 length = security_set_bools(fsi->state, fsi->bool_num,
1312                                             fsi->bool_pending_values);
1313
1314         if (!length)
1315                 length = count;
1316
1317 out:
1318         mutex_unlock(&fsi->mutex);
1319         kfree(page);
1320         return length;
1321 }
1322
1323 static const struct file_operations sel_commit_bools_ops = {
1324         .write          = sel_commit_bools_write,
1325         .llseek         = generic_file_llseek,
1326 };
1327
1328 static void sel_remove_entries(struct dentry *de)
1329 {
1330         d_genocide(de);
1331         shrink_dcache_parent(de);
1332 }
1333
1334 #define BOOL_DIR_NAME "booleans"
1335
1336 static int sel_make_bools(struct selinux_fs_info *fsi)
1337 {
1338         int ret;
1339         ssize_t len;
1340         struct dentry *dentry = NULL;
1341         struct dentry *dir = fsi->bool_dir;
1342         struct inode *inode = NULL;
1343         struct inode_security_struct *isec;
1344         char **names = NULL, *page;
1345         u32 i, num;
1346         int *values = NULL;
1347         u32 sid;
1348
1349         /* remove any existing files */
1350         for (i = 0; i < fsi->bool_num; i++)
1351                 kfree(fsi->bool_pending_names[i]);
1352         kfree(fsi->bool_pending_names);
1353         kfree(fsi->bool_pending_values);
1354         fsi->bool_num = 0;
1355         fsi->bool_pending_names = NULL;
1356         fsi->bool_pending_values = NULL;
1357
1358         sel_remove_entries(dir);
1359
1360         ret = -ENOMEM;
1361         page = (char *)get_zeroed_page(GFP_KERNEL);
1362         if (!page)
1363                 goto out;
1364
1365         ret = security_get_bools(fsi->state, &num, &names, &values);
1366         if (ret)
1367                 goto out;
1368
1369         for (i = 0; i < num; i++) {
1370                 ret = -ENOMEM;
1371                 dentry = d_alloc_name(dir, names[i]);
1372                 if (!dentry)
1373                         goto out;
1374
1375                 ret = -ENOMEM;
1376                 inode = sel_make_inode(dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1377                 if (!inode) {
1378                         dput(dentry);
1379                         goto out;
1380                 }
1381
1382                 ret = -ENAMETOOLONG;
1383                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1384                 if (len >= PAGE_SIZE) {
1385                         dput(dentry);
1386                         iput(inode);
1387                         goto out;
1388                 }
1389
1390                 isec = selinux_inode(inode);
1391                 ret = security_genfs_sid(fsi->state, "selinuxfs", page,
1392                                          SECCLASS_FILE, &sid);
1393                 if (ret) {
1394                         pr_warn_ratelimited("SELinux: no sid found, defaulting to security isid for %s\n",
1395                                            page);
1396                         sid = SECINITSID_SECURITY;
1397                 }
1398
1399                 isec->sid = sid;
1400                 isec->initialized = LABEL_INITIALIZED;
1401                 inode->i_fop = &sel_bool_ops;
1402                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1403                 d_add(dentry, inode);
1404         }
1405         fsi->bool_num = num;
1406         fsi->bool_pending_names = names;
1407         fsi->bool_pending_values = values;
1408
1409         free_page((unsigned long)page);
1410         return 0;
1411 out:
1412         free_page((unsigned long)page);
1413
1414         if (names) {
1415                 for (i = 0; i < num; i++)
1416                         kfree(names[i]);
1417                 kfree(names);
1418         }
1419         kfree(values);
1420         sel_remove_entries(dir);
1421
1422         return ret;
1423 }
1424
1425 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1426                                             size_t count, loff_t *ppos)
1427 {
1428         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
1429         struct selinux_state *state = fsi->state;
1430         char tmpbuf[TMPBUFLEN];
1431         ssize_t length;
1432
1433         length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1434                            avc_get_cache_threshold(state->avc));
1435         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1436 }
1437
1438 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1439                                              const char __user *buf,
1440                                              size_t count, loff_t *ppos)
1441
1442 {
1443         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1444         struct selinux_state *state = fsi->state;
1445         char *page;
1446         ssize_t ret;
1447         unsigned int new_value;
1448
1449         ret = avc_has_perm(&selinux_state,
1450                            current_sid(), SECINITSID_SECURITY,
1451                            SECCLASS_SECURITY, SECURITY__SETSECPARAM,
1452                            NULL);
1453         if (ret)
1454                 return ret;
1455
1456         if (count >= PAGE_SIZE)
1457                 return -ENOMEM;
1458
1459         /* No partial writes. */
1460         if (*ppos != 0)
1461                 return -EINVAL;
1462
1463         page = memdup_user_nul(buf, count);
1464         if (IS_ERR(page))
1465                 return PTR_ERR(page);
1466
1467         ret = -EINVAL;
1468         if (sscanf(page, "%u", &new_value) != 1)
1469                 goto out;
1470
1471         avc_set_cache_threshold(state->avc, new_value);
1472
1473         ret = count;
1474 out:
1475         kfree(page);
1476         return ret;
1477 }
1478
1479 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1480                                        size_t count, loff_t *ppos)
1481 {
1482         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
1483         struct selinux_state *state = fsi->state;
1484         char *page;
1485         ssize_t length;
1486
1487         page = (char *)__get_free_page(GFP_KERNEL);
1488         if (!page)
1489                 return -ENOMEM;
1490
1491         length = avc_get_hash_stats(state->avc, page);
1492         if (length >= 0)
1493                 length = simple_read_from_buffer(buf, count, ppos, page, length);
1494         free_page((unsigned long)page);
1495
1496         return length;
1497 }
1498
1499 static ssize_t sel_read_sidtab_hash_stats(struct file *filp, char __user *buf,
1500                                         size_t count, loff_t *ppos)
1501 {
1502         struct selinux_fs_info *fsi = file_inode(filp)->i_sb->s_fs_info;
1503         struct selinux_state *state = fsi->state;
1504         char *page;
1505         ssize_t length;
1506
1507         page = (char *)__get_free_page(GFP_KERNEL);
1508         if (!page)
1509                 return -ENOMEM;
1510
1511         length = security_sidtab_hash_stats(state, page);
1512         if (length >= 0)
1513                 length = simple_read_from_buffer(buf, count, ppos, page,
1514                                                 length);
1515         free_page((unsigned long)page);
1516
1517         return length;
1518 }
1519
1520 static const struct file_operations sel_sidtab_hash_stats_ops = {
1521         .read           = sel_read_sidtab_hash_stats,
1522         .llseek         = generic_file_llseek,
1523 };
1524
1525 static const struct file_operations sel_avc_cache_threshold_ops = {
1526         .read           = sel_read_avc_cache_threshold,
1527         .write          = sel_write_avc_cache_threshold,
1528         .llseek         = generic_file_llseek,
1529 };
1530
1531 static const struct file_operations sel_avc_hash_stats_ops = {
1532         .read           = sel_read_avc_hash_stats,
1533         .llseek         = generic_file_llseek,
1534 };
1535
1536 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1537 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1538 {
1539         int cpu;
1540
1541         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1542                 if (!cpu_possible(cpu))
1543                         continue;
1544                 *idx = cpu + 1;
1545                 return &per_cpu(avc_cache_stats, cpu);
1546         }
1547         (*idx)++;
1548         return NULL;
1549 }
1550
1551 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1552 {
1553         loff_t n = *pos - 1;
1554
1555         if (*pos == 0)
1556                 return SEQ_START_TOKEN;
1557
1558         return sel_avc_get_stat_idx(&n);
1559 }
1560
1561 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1562 {
1563         return sel_avc_get_stat_idx(pos);
1564 }
1565
1566 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1567 {
1568         struct avc_cache_stats *st = v;
1569
1570         if (v == SEQ_START_TOKEN) {
1571                 seq_puts(seq,
1572                          "lookups hits misses allocations reclaims frees\n");
1573         } else {
1574                 unsigned int lookups = st->lookups;
1575                 unsigned int misses = st->misses;
1576                 unsigned int hits = lookups - misses;
1577                 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1578                            hits, misses, st->allocations,
1579                            st->reclaims, st->frees);
1580         }
1581         return 0;
1582 }
1583
1584 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1585 { }
1586
1587 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1588         .start          = sel_avc_stats_seq_start,
1589         .next           = sel_avc_stats_seq_next,
1590         .show           = sel_avc_stats_seq_show,
1591         .stop           = sel_avc_stats_seq_stop,
1592 };
1593
1594 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1595 {
1596         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1597 }
1598
1599 static const struct file_operations sel_avc_cache_stats_ops = {
1600         .open           = sel_open_avc_cache_stats,
1601         .read           = seq_read,
1602         .llseek         = seq_lseek,
1603         .release        = seq_release,
1604 };
1605 #endif
1606
1607 static int sel_make_avc_files(struct dentry *dir)
1608 {
1609         struct super_block *sb = dir->d_sb;
1610         struct selinux_fs_info *fsi = sb->s_fs_info;
1611         int i;
1612         static const struct tree_descr files[] = {
1613                 { "cache_threshold",
1614                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1615                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1616 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1617                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1618 #endif
1619         };
1620
1621         for (i = 0; i < ARRAY_SIZE(files); i++) {
1622                 struct inode *inode;
1623                 struct dentry *dentry;
1624
1625                 dentry = d_alloc_name(dir, files[i].name);
1626                 if (!dentry)
1627                         return -ENOMEM;
1628
1629                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1630                 if (!inode) {
1631                         dput(dentry);
1632                         return -ENOMEM;
1633                 }
1634
1635                 inode->i_fop = files[i].ops;
1636                 inode->i_ino = ++fsi->last_ino;
1637                 d_add(dentry, inode);
1638         }
1639
1640         return 0;
1641 }
1642
1643 static int sel_make_ss_files(struct dentry *dir)
1644 {
1645         struct super_block *sb = dir->d_sb;
1646         struct selinux_fs_info *fsi = sb->s_fs_info;
1647         int i;
1648         static struct tree_descr files[] = {
1649                 { "sidtab_hash_stats", &sel_sidtab_hash_stats_ops, S_IRUGO },
1650         };
1651
1652         for (i = 0; i < ARRAY_SIZE(files); i++) {
1653                 struct inode *inode;
1654                 struct dentry *dentry;
1655
1656                 dentry = d_alloc_name(dir, files[i].name);
1657                 if (!dentry)
1658                         return -ENOMEM;
1659
1660                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1661                 if (!inode) {
1662                         dput(dentry);
1663                         return -ENOMEM;
1664                 }
1665
1666                 inode->i_fop = files[i].ops;
1667                 inode->i_ino = ++fsi->last_ino;
1668                 d_add(dentry, inode);
1669         }
1670
1671         return 0;
1672 }
1673
1674 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1675                                 size_t count, loff_t *ppos)
1676 {
1677         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1678         char *con;
1679         u32 sid, len;
1680         ssize_t ret;
1681
1682         sid = file_inode(file)->i_ino&SEL_INO_MASK;
1683         ret = security_sid_to_context(fsi->state, sid, &con, &len);
1684         if (ret)
1685                 return ret;
1686
1687         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1688         kfree(con);
1689         return ret;
1690 }
1691
1692 static const struct file_operations sel_initcon_ops = {
1693         .read           = sel_read_initcon,
1694         .llseek         = generic_file_llseek,
1695 };
1696
1697 static int sel_make_initcon_files(struct dentry *dir)
1698 {
1699         int i;
1700
1701         for (i = 1; i <= SECINITSID_NUM; i++) {
1702                 struct inode *inode;
1703                 struct dentry *dentry;
1704                 const char *s = security_get_initial_sid_context(i);
1705
1706                 if (!s)
1707                         continue;
1708                 dentry = d_alloc_name(dir, s);
1709                 if (!dentry)
1710                         return -ENOMEM;
1711
1712                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1713                 if (!inode) {
1714                         dput(dentry);
1715                         return -ENOMEM;
1716                 }
1717
1718                 inode->i_fop = &sel_initcon_ops;
1719                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1720                 d_add(dentry, inode);
1721         }
1722
1723         return 0;
1724 }
1725
1726 static inline unsigned long sel_class_to_ino(u16 class)
1727 {
1728         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1729 }
1730
1731 static inline u16 sel_ino_to_class(unsigned long ino)
1732 {
1733         return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1734 }
1735
1736 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1737 {
1738         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1739 }
1740
1741 static inline u32 sel_ino_to_perm(unsigned long ino)
1742 {
1743         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1744 }
1745
1746 static ssize_t sel_read_class(struct file *file, char __user *buf,
1747                                 size_t count, loff_t *ppos)
1748 {
1749         unsigned long ino = file_inode(file)->i_ino;
1750         char res[TMPBUFLEN];
1751         ssize_t len = scnprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1752         return simple_read_from_buffer(buf, count, ppos, res, len);
1753 }
1754
1755 static const struct file_operations sel_class_ops = {
1756         .read           = sel_read_class,
1757         .llseek         = generic_file_llseek,
1758 };
1759
1760 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1761                                 size_t count, loff_t *ppos)
1762 {
1763         unsigned long ino = file_inode(file)->i_ino;
1764         char res[TMPBUFLEN];
1765         ssize_t len = scnprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1766         return simple_read_from_buffer(buf, count, ppos, res, len);
1767 }
1768
1769 static const struct file_operations sel_perm_ops = {
1770         .read           = sel_read_perm,
1771         .llseek         = generic_file_llseek,
1772 };
1773
1774 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1775                                   size_t count, loff_t *ppos)
1776 {
1777         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
1778         int value;
1779         char tmpbuf[TMPBUFLEN];
1780         ssize_t length;
1781         unsigned long i_ino = file_inode(file)->i_ino;
1782
1783         value = security_policycap_supported(fsi->state, i_ino & SEL_INO_MASK);
1784         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1785
1786         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1787 }
1788
1789 static const struct file_operations sel_policycap_ops = {
1790         .read           = sel_read_policycap,
1791         .llseek         = generic_file_llseek,
1792 };
1793
1794 static int sel_make_perm_files(char *objclass, int classvalue,
1795                                 struct dentry *dir)
1796 {
1797         struct selinux_fs_info *fsi = dir->d_sb->s_fs_info;
1798         int i, rc, nperms;
1799         char **perms;
1800
1801         rc = security_get_permissions(fsi->state, objclass, &perms, &nperms);
1802         if (rc)
1803                 return rc;
1804
1805         for (i = 0; i < nperms; i++) {
1806                 struct inode *inode;
1807                 struct dentry *dentry;
1808
1809                 rc = -ENOMEM;
1810                 dentry = d_alloc_name(dir, perms[i]);
1811                 if (!dentry)
1812                         goto out;
1813
1814                 rc = -ENOMEM;
1815                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1816                 if (!inode) {
1817                         dput(dentry);
1818                         goto out;
1819                 }
1820
1821                 inode->i_fop = &sel_perm_ops;
1822                 /* i+1 since perm values are 1-indexed */
1823                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1824                 d_add(dentry, inode);
1825         }
1826         rc = 0;
1827 out:
1828         for (i = 0; i < nperms; i++)
1829                 kfree(perms[i]);
1830         kfree(perms);
1831         return rc;
1832 }
1833
1834 static int sel_make_class_dir_entries(char *classname, int index,
1835                                         struct dentry *dir)
1836 {
1837         struct super_block *sb = dir->d_sb;
1838         struct selinux_fs_info *fsi = sb->s_fs_info;
1839         struct dentry *dentry = NULL;
1840         struct inode *inode = NULL;
1841         int rc;
1842
1843         dentry = d_alloc_name(dir, "index");
1844         if (!dentry)
1845                 return -ENOMEM;
1846
1847         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1848         if (!inode) {
1849                 dput(dentry);
1850                 return -ENOMEM;
1851         }
1852
1853         inode->i_fop = &sel_class_ops;
1854         inode->i_ino = sel_class_to_ino(index);
1855         d_add(dentry, inode);
1856
1857         dentry = sel_make_dir(dir, "perms", &fsi->last_class_ino);
1858         if (IS_ERR(dentry))
1859                 return PTR_ERR(dentry);
1860
1861         rc = sel_make_perm_files(classname, index, dentry);
1862
1863         return rc;
1864 }
1865
1866 static int sel_make_classes(struct selinux_fs_info *fsi)
1867 {
1868
1869         int rc, nclasses, i;
1870         char **classes;
1871
1872         /* delete any existing entries */
1873         sel_remove_entries(fsi->class_dir);
1874
1875         rc = security_get_classes(fsi->state, &classes, &nclasses);
1876         if (rc)
1877                 return rc;
1878
1879         /* +2 since classes are 1-indexed */
1880         fsi->last_class_ino = sel_class_to_ino(nclasses + 2);
1881
1882         for (i = 0; i < nclasses; i++) {
1883                 struct dentry *class_name_dir;
1884
1885                 class_name_dir = sel_make_dir(fsi->class_dir, classes[i],
1886                                               &fsi->last_class_ino);
1887                 if (IS_ERR(class_name_dir)) {
1888                         rc = PTR_ERR(class_name_dir);
1889                         goto out;
1890                 }
1891
1892                 /* i+1 since class values are 1-indexed */
1893                 rc = sel_make_class_dir_entries(classes[i], i + 1,
1894                                 class_name_dir);
1895                 if (rc)
1896                         goto out;
1897         }
1898         rc = 0;
1899 out:
1900         for (i = 0; i < nclasses; i++)
1901                 kfree(classes[i]);
1902         kfree(classes);
1903         return rc;
1904 }
1905
1906 static int sel_make_policycap(struct selinux_fs_info *fsi)
1907 {
1908         unsigned int iter;
1909         struct dentry *dentry = NULL;
1910         struct inode *inode = NULL;
1911
1912         sel_remove_entries(fsi->policycap_dir);
1913
1914         for (iter = 0; iter <= POLICYDB_CAPABILITY_MAX; iter++) {
1915                 if (iter < ARRAY_SIZE(selinux_policycap_names))
1916                         dentry = d_alloc_name(fsi->policycap_dir,
1917                                               selinux_policycap_names[iter]);
1918                 else
1919                         dentry = d_alloc_name(fsi->policycap_dir, "unknown");
1920
1921                 if (dentry == NULL)
1922                         return -ENOMEM;
1923
1924                 inode = sel_make_inode(fsi->sb, S_IFREG | 0444);
1925                 if (inode == NULL) {
1926                         dput(dentry);
1927                         return -ENOMEM;
1928                 }
1929
1930                 inode->i_fop = &sel_policycap_ops;
1931                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1932                 d_add(dentry, inode);
1933         }
1934
1935         return 0;
1936 }
1937
1938 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1939                         unsigned long *ino)
1940 {
1941         struct dentry *dentry = d_alloc_name(dir, name);
1942         struct inode *inode;
1943
1944         if (!dentry)
1945                 return ERR_PTR(-ENOMEM);
1946
1947         inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1948         if (!inode) {
1949                 dput(dentry);
1950                 return ERR_PTR(-ENOMEM);
1951         }
1952
1953         inode->i_op = &simple_dir_inode_operations;
1954         inode->i_fop = &simple_dir_operations;
1955         inode->i_ino = ++(*ino);
1956         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1957         inc_nlink(inode);
1958         d_add(dentry, inode);
1959         /* bump link count on parent directory, too */
1960         inc_nlink(d_inode(dir));
1961
1962         return dentry;
1963 }
1964
1965 #define NULL_FILE_NAME "null"
1966
1967 static int sel_fill_super(struct super_block *sb, struct fs_context *fc)
1968 {
1969         struct selinux_fs_info *fsi;
1970         int ret;
1971         struct dentry *dentry;
1972         struct inode *inode;
1973         struct inode_security_struct *isec;
1974
1975         static const struct tree_descr selinux_files[] = {
1976                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1977                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1978                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1979                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1980                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1981                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1982                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1983                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1984                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1985                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1986                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
1987                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
1988                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
1989                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
1990                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
1991                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
1992                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
1993                 [SEL_VALIDATE_TRANS] = {"validatetrans", &sel_transition_ops,
1994                                         S_IWUGO},
1995                 /* last one */ {""}
1996         };
1997
1998         ret = selinux_fs_info_create(sb);
1999         if (ret)
2000                 goto err;
2001
2002         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
2003         if (ret)
2004                 goto err;
2005
2006         fsi = sb->s_fs_info;
2007         fsi->bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &fsi->last_ino);
2008         if (IS_ERR(fsi->bool_dir)) {
2009                 ret = PTR_ERR(fsi->bool_dir);
2010                 fsi->bool_dir = NULL;
2011                 goto err;
2012         }
2013
2014         ret = -ENOMEM;
2015         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
2016         if (!dentry)
2017                 goto err;
2018
2019         ret = -ENOMEM;
2020         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
2021         if (!inode) {
2022                 dput(dentry);
2023                 goto err;
2024         }
2025
2026         inode->i_ino = ++fsi->last_ino;
2027         isec = selinux_inode(inode);
2028         isec->sid = SECINITSID_DEVNULL;
2029         isec->sclass = SECCLASS_CHR_FILE;
2030         isec->initialized = LABEL_INITIALIZED;
2031
2032         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
2033         d_add(dentry, inode);
2034
2035         dentry = sel_make_dir(sb->s_root, "avc", &fsi->last_ino);
2036         if (IS_ERR(dentry)) {
2037                 ret = PTR_ERR(dentry);
2038                 goto err;
2039         }
2040
2041         ret = sel_make_avc_files(dentry);
2042
2043         dentry = sel_make_dir(sb->s_root, "ss", &fsi->last_ino);
2044         if (IS_ERR(dentry)) {
2045                 ret = PTR_ERR(dentry);
2046                 goto err;
2047         }
2048
2049         ret = sel_make_ss_files(dentry);
2050         if (ret)
2051                 goto err;
2052
2053         dentry = sel_make_dir(sb->s_root, "initial_contexts", &fsi->last_ino);
2054         if (IS_ERR(dentry)) {
2055                 ret = PTR_ERR(dentry);
2056                 goto err;
2057         }
2058
2059         ret = sel_make_initcon_files(dentry);
2060         if (ret)
2061                 goto err;
2062
2063         fsi->class_dir = sel_make_dir(sb->s_root, "class", &fsi->last_ino);
2064         if (IS_ERR(fsi->class_dir)) {
2065                 ret = PTR_ERR(fsi->class_dir);
2066                 fsi->class_dir = NULL;
2067                 goto err;
2068         }
2069
2070         fsi->policycap_dir = sel_make_dir(sb->s_root, "policy_capabilities",
2071                                           &fsi->last_ino);
2072         if (IS_ERR(fsi->policycap_dir)) {
2073                 ret = PTR_ERR(fsi->policycap_dir);
2074                 fsi->policycap_dir = NULL;
2075                 goto err;
2076         }
2077
2078         ret = sel_make_policy_nodes(fsi);
2079         if (ret)
2080                 goto err;
2081         return 0;
2082 err:
2083         pr_err("SELinux: %s:  failed while creating inodes\n",
2084                 __func__);
2085
2086         selinux_fs_info_free(sb);
2087
2088         return ret;
2089 }
2090
2091 static int sel_get_tree(struct fs_context *fc)
2092 {
2093         return get_tree_single(fc, sel_fill_super);
2094 }
2095
2096 static const struct fs_context_operations sel_context_ops = {
2097         .get_tree       = sel_get_tree,
2098 };
2099
2100 static int sel_init_fs_context(struct fs_context *fc)
2101 {
2102         fc->ops = &sel_context_ops;
2103         return 0;
2104 }
2105
2106 static void sel_kill_sb(struct super_block *sb)
2107 {
2108         selinux_fs_info_free(sb);
2109         kill_litter_super(sb);
2110 }
2111
2112 static struct file_system_type sel_fs_type = {
2113         .name           = "selinuxfs",
2114         .init_fs_context = sel_init_fs_context,
2115         .kill_sb        = sel_kill_sb,
2116 };
2117
2118 struct vfsmount *selinuxfs_mount;
2119 struct path selinux_null;
2120
2121 static int __init init_sel_fs(void)
2122 {
2123         struct qstr null_name = QSTR_INIT(NULL_FILE_NAME,
2124                                           sizeof(NULL_FILE_NAME)-1);
2125         int err;
2126
2127         if (!selinux_enabled_boot)
2128                 return 0;
2129
2130         err = sysfs_create_mount_point(fs_kobj, "selinux");
2131         if (err)
2132                 return err;
2133
2134         err = register_filesystem(&sel_fs_type);
2135         if (err) {
2136                 sysfs_remove_mount_point(fs_kobj, "selinux");
2137                 return err;
2138         }
2139
2140         selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
2141         if (IS_ERR(selinuxfs_mount)) {
2142                 pr_err("selinuxfs:  could not mount!\n");
2143                 err = PTR_ERR(selinuxfs_mount);
2144                 selinuxfs_mount = NULL;
2145         }
2146         selinux_null.dentry = d_hash_and_lookup(selinux_null.mnt->mnt_root,
2147                                                 &null_name);
2148         if (IS_ERR(selinux_null.dentry)) {
2149                 pr_err("selinuxfs:  could not lookup null!\n");
2150                 err = PTR_ERR(selinux_null.dentry);
2151                 selinux_null.dentry = NULL;
2152         }
2153
2154         return err;
2155 }
2156
2157 __initcall(init_sel_fs);
2158
2159 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
2160 void exit_sel_fs(void)
2161 {
2162         sysfs_remove_mount_point(fs_kobj, "selinux");
2163         dput(selinux_null.dentry);
2164         kern_unmount(selinuxfs_mount);
2165         unregister_filesystem(&sel_fs_type);
2166 }
2167 #endif