Merge tag 'ntfs3_for_6.4' of https://github.com/Paragon-Software-Group/linux-ntfs3
[linux-block.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/namei.h>
24 #include <linux/init.h>
25 #include <linux/string.h>
26 #include <linux/security.h>
27 #include <linux/major.h>
28 #include <linux/seq_file.h>
29 #include <linux/percpu.h>
30 #include <linux/audit.h>
31 #include <linux/uaccess.h>
32 #include <linux/kobject.h>
33 #include <linux/ctype.h>
34
35 /* selinuxfs pseudo filesystem for exporting the security policy API.
36    Based on the proc code and the fs/nfsd/nfsctl.c code. */
37
38 #include "flask.h"
39 #include "avc.h"
40 #include "avc_ss.h"
41 #include "security.h"
42 #include "objsec.h"
43 #include "conditional.h"
44 #include "ima.h"
45
46 enum sel_inos {
47         SEL_ROOT_INO = 2,
48         SEL_LOAD,       /* load policy */
49         SEL_ENFORCE,    /* get or set enforcing status */
50         SEL_CONTEXT,    /* validate context */
51         SEL_ACCESS,     /* compute access decision */
52         SEL_CREATE,     /* compute create labeling decision */
53         SEL_RELABEL,    /* compute relabeling decision */
54         SEL_USER,       /* compute reachable user contexts */
55         SEL_POLICYVERS, /* return policy version for this kernel */
56         SEL_COMMIT_BOOLS, /* commit new boolean values */
57         SEL_MLS,        /* return if MLS policy is enabled */
58         SEL_DISABLE,    /* disable SELinux until next reboot */
59         SEL_MEMBER,     /* compute polyinstantiation membership decision */
60         SEL_CHECKREQPROT, /* check requested protection, not kernel-applied one */
61         SEL_COMPAT_NET, /* whether to use old compat network packet controls */
62         SEL_REJECT_UNKNOWN, /* export unknown reject handling to userspace */
63         SEL_DENY_UNKNOWN, /* export unknown deny handling to userspace */
64         SEL_STATUS,     /* export current status using mmap() */
65         SEL_POLICY,     /* allow userspace to read the in kernel policy */
66         SEL_VALIDATE_TRANS, /* compute validatetrans decision */
67         SEL_INO_NEXT,   /* The next inode number to use */
68 };
69
70 struct selinux_fs_info {
71         struct dentry *bool_dir;
72         unsigned int bool_num;
73         char **bool_pending_names;
74         int *bool_pending_values;
75         struct dentry *class_dir;
76         unsigned long last_class_ino;
77         bool policy_opened;
78         struct dentry *policycap_dir;
79         unsigned long last_ino;
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         fsi->last_ino = SEL_INO_NEXT - 1;
92         fsi->sb = sb;
93         sb->s_fs_info = fsi;
94         return 0;
95 }
96
97 static void selinux_fs_info_free(struct super_block *sb)
98 {
99         struct selinux_fs_info *fsi = sb->s_fs_info;
100         int i;
101
102         if (fsi) {
103                 for (i = 0; i < fsi->bool_num; i++)
104                         kfree(fsi->bool_pending_names[i]);
105                 kfree(fsi->bool_pending_names);
106                 kfree(fsi->bool_pending_values);
107         }
108         kfree(sb->s_fs_info);
109         sb->s_fs_info = NULL;
110 }
111
112 #define SEL_INITCON_INO_OFFSET          0x01000000
113 #define SEL_BOOL_INO_OFFSET             0x02000000
114 #define SEL_CLASS_INO_OFFSET            0x04000000
115 #define SEL_POLICYCAP_INO_OFFSET        0x08000000
116 #define SEL_INO_MASK                    0x00ffffff
117
118 #define BOOL_DIR_NAME "booleans"
119 #define CLASS_DIR_NAME "class"
120 #define POLICYCAP_DIR_NAME "policy_capabilities"
121
122 #define TMPBUFLEN       12
123 static ssize_t sel_read_enforce(struct file *filp, char __user *buf,
124                                 size_t count, loff_t *ppos)
125 {
126         char tmpbuf[TMPBUFLEN];
127         ssize_t length;
128
129         length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
130                            enforcing_enabled());
131         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
132 }
133
134 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
135 static ssize_t sel_write_enforce(struct file *file, const char __user *buf,
136                                  size_t count, loff_t *ppos)
137
138 {
139         char *page = NULL;
140         ssize_t length;
141         int old_value, new_value;
142
143         if (count >= PAGE_SIZE)
144                 return -ENOMEM;
145
146         /* No partial writes. */
147         if (*ppos != 0)
148                 return -EINVAL;
149
150         page = memdup_user_nul(buf, count);
151         if (IS_ERR(page))
152                 return PTR_ERR(page);
153
154         length = -EINVAL;
155         if (sscanf(page, "%d", &new_value) != 1)
156                 goto out;
157
158         new_value = !!new_value;
159
160         old_value = enforcing_enabled();
161         if (new_value != old_value) {
162                 length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
163                                       SECCLASS_SECURITY, SECURITY__SETENFORCE,
164                                       NULL);
165                 if (length)
166                         goto out;
167                 audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_STATUS,
168                         "enforcing=%d old_enforcing=%d auid=%u ses=%u"
169                         " enabled=1 old-enabled=1 lsm=selinux res=1",
170                         new_value, old_value,
171                         from_kuid(&init_user_ns, audit_get_loginuid(current)),
172                         audit_get_sessionid(current));
173                 enforcing_set(new_value);
174                 if (new_value)
175                         avc_ss_reset(0);
176                 selnl_notify_setenforce(new_value);
177                 selinux_status_update_setenforce(new_value);
178                 if (!new_value)
179                         call_blocking_lsm_notifier(LSM_POLICY_CHANGE, NULL);
180
181                 selinux_ima_measure_state();
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         char tmpbuf[TMPBUFLEN];
202         ssize_t length;
203         ino_t ino = file_inode(filp)->i_ino;
204         int handle_unknown = (ino == SEL_REJECT_UNKNOWN) ?
205                 security_get_reject_unknown() :
206                 !security_get_allow_unknown();
207
208         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", handle_unknown);
209         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
210 }
211
212 static const struct file_operations sel_handle_unknown_ops = {
213         .read           = sel_read_handle_unknown,
214         .llseek         = generic_file_llseek,
215 };
216
217 static int sel_open_handle_status(struct inode *inode, struct file *filp)
218 {
219         struct page    *status = selinux_kernel_status_page();
220
221         if (!status)
222                 return -ENOMEM;
223
224         filp->private_data = status;
225
226         return 0;
227 }
228
229 static ssize_t sel_read_handle_status(struct file *filp, char __user *buf,
230                                       size_t count, loff_t *ppos)
231 {
232         struct page    *status = filp->private_data;
233
234         BUG_ON(!status);
235
236         return simple_read_from_buffer(buf, count, ppos,
237                                        page_address(status),
238                                        sizeof(struct selinux_kernel_status));
239 }
240
241 static int sel_mmap_handle_status(struct file *filp,
242                                   struct vm_area_struct *vma)
243 {
244         struct page    *status = filp->private_data;
245         unsigned long   size = vma->vm_end - vma->vm_start;
246
247         BUG_ON(!status);
248
249         /* only allows one page from the head */
250         if (vma->vm_pgoff > 0 || size != PAGE_SIZE)
251                 return -EIO;
252         /* disallow writable mapping */
253         if (vma->vm_flags & VM_WRITE)
254                 return -EPERM;
255         /* disallow mprotect() turns it into writable */
256         vm_flags_clear(vma, VM_MAYWRITE);
257
258         return remap_pfn_range(vma, vma->vm_start,
259                                page_to_pfn(status),
260                                size, vma->vm_page_prot);
261 }
262
263 static const struct file_operations sel_handle_status_ops = {
264         .open           = sel_open_handle_status,
265         .read           = sel_read_handle_status,
266         .mmap           = sel_mmap_handle_status,
267         .llseek         = generic_file_llseek,
268 };
269
270 static ssize_t sel_write_disable(struct file *file, const char __user *buf,
271                                  size_t count, loff_t *ppos)
272
273 {
274         char *page;
275         ssize_t length;
276         int new_value;
277
278         if (count >= PAGE_SIZE)
279                 return -ENOMEM;
280
281         /* No partial writes. */
282         if (*ppos != 0)
283                 return -EINVAL;
284
285         page = memdup_user_nul(buf, count);
286         if (IS_ERR(page))
287                 return PTR_ERR(page);
288
289         if (sscanf(page, "%d", &new_value) != 1) {
290                 length = -EINVAL;
291                 goto out;
292         }
293         length = count;
294
295         if (new_value) {
296                 pr_err("SELinux: https://github.com/SELinuxProject/selinux-kernel/wiki/DEPRECATE-runtime-disable\n");
297                 pr_err("SELinux: Runtime disable is not supported, use selinux=0 on the kernel cmdline.\n");
298         }
299
300 out:
301         kfree(page);
302         return length;
303 }
304
305 static const struct file_operations sel_disable_ops = {
306         .write          = sel_write_disable,
307         .llseek         = generic_file_llseek,
308 };
309
310 static ssize_t sel_read_policyvers(struct file *filp, char __user *buf,
311                                    size_t count, loff_t *ppos)
312 {
313         char tmpbuf[TMPBUFLEN];
314         ssize_t length;
315
316         length = scnprintf(tmpbuf, TMPBUFLEN, "%u", POLICYDB_VERSION_MAX);
317         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
318 }
319
320 static const struct file_operations sel_policyvers_ops = {
321         .read           = sel_read_policyvers,
322         .llseek         = generic_file_llseek,
323 };
324
325 /* declaration for sel_write_load */
326 static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_dir,
327                           unsigned int *bool_num, char ***bool_pending_names,
328                           int **bool_pending_values);
329 static int sel_make_classes(struct selinux_policy *newpolicy,
330                             struct dentry *class_dir,
331                             unsigned long *last_class_ino);
332
333 /* declaration for sel_make_class_dirs */
334 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
335                         unsigned long *ino);
336
337 /* declaration for sel_make_policy_nodes */
338 static struct dentry *sel_make_disconnected_dir(struct super_block *sb,
339                                                 unsigned long *ino);
340
341 /* declaration for sel_make_policy_nodes */
342 static void sel_remove_entries(struct dentry *de);
343
344 static ssize_t sel_read_mls(struct file *filp, char __user *buf,
345                                 size_t count, loff_t *ppos)
346 {
347         char tmpbuf[TMPBUFLEN];
348         ssize_t length;
349
350         length = scnprintf(tmpbuf, TMPBUFLEN, "%d",
351                            security_mls_enabled());
352         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
353 }
354
355 static const struct file_operations sel_mls_ops = {
356         .read           = sel_read_mls,
357         .llseek         = generic_file_llseek,
358 };
359
360 struct policy_load_memory {
361         size_t len;
362         void *data;
363 };
364
365 static int sel_open_policy(struct inode *inode, struct file *filp)
366 {
367         struct selinux_fs_info *fsi = inode->i_sb->s_fs_info;
368         struct policy_load_memory *plm = NULL;
369         int rc;
370
371         BUG_ON(filp->private_data);
372
373         mutex_lock(&selinux_state.policy_mutex);
374
375         rc = avc_has_perm(current_sid(), SECINITSID_SECURITY,
376                           SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL);
377         if (rc)
378                 goto err;
379
380         rc = -EBUSY;
381         if (fsi->policy_opened)
382                 goto err;
383
384         rc = -ENOMEM;
385         plm = kzalloc(sizeof(*plm), GFP_KERNEL);
386         if (!plm)
387                 goto err;
388
389         rc = security_read_policy(&plm->data, &plm->len);
390         if (rc)
391                 goto err;
392
393         if ((size_t)i_size_read(inode) != plm->len) {
394                 inode_lock(inode);
395                 i_size_write(inode, plm->len);
396                 inode_unlock(inode);
397         }
398
399         fsi->policy_opened = 1;
400
401         filp->private_data = plm;
402
403         mutex_unlock(&selinux_state.policy_mutex);
404
405         return 0;
406 err:
407         mutex_unlock(&selinux_state.policy_mutex);
408
409         if (plm)
410                 vfree(plm->data);
411         kfree(plm);
412         return rc;
413 }
414
415 static int sel_release_policy(struct inode *inode, struct file *filp)
416 {
417         struct selinux_fs_info *fsi = inode->i_sb->s_fs_info;
418         struct policy_load_memory *plm = filp->private_data;
419
420         BUG_ON(!plm);
421
422         fsi->policy_opened = 0;
423
424         vfree(plm->data);
425         kfree(plm);
426
427         return 0;
428 }
429
430 static ssize_t sel_read_policy(struct file *filp, char __user *buf,
431                                size_t count, loff_t *ppos)
432 {
433         struct policy_load_memory *plm = filp->private_data;
434         int ret;
435
436         ret = avc_has_perm(current_sid(), SECINITSID_SECURITY,
437                           SECCLASS_SECURITY, SECURITY__READ_POLICY, NULL);
438         if (ret)
439                 return ret;
440
441         return simple_read_from_buffer(buf, count, ppos, plm->data, plm->len);
442 }
443
444 static vm_fault_t sel_mmap_policy_fault(struct vm_fault *vmf)
445 {
446         struct policy_load_memory *plm = vmf->vma->vm_file->private_data;
447         unsigned long offset;
448         struct page *page;
449
450         if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
451                 return VM_FAULT_SIGBUS;
452
453         offset = vmf->pgoff << PAGE_SHIFT;
454         if (offset >= roundup(plm->len, PAGE_SIZE))
455                 return VM_FAULT_SIGBUS;
456
457         page = vmalloc_to_page(plm->data + offset);
458         get_page(page);
459
460         vmf->page = page;
461
462         return 0;
463 }
464
465 static const struct vm_operations_struct sel_mmap_policy_ops = {
466         .fault = sel_mmap_policy_fault,
467         .page_mkwrite = sel_mmap_policy_fault,
468 };
469
470 static int sel_mmap_policy(struct file *filp, struct vm_area_struct *vma)
471 {
472         if (vma->vm_flags & VM_SHARED) {
473                 /* do not allow mprotect to make mapping writable */
474                 vm_flags_clear(vma, VM_MAYWRITE);
475
476                 if (vma->vm_flags & VM_WRITE)
477                         return -EACCES;
478         }
479
480         vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
481         vma->vm_ops = &sel_mmap_policy_ops;
482
483         return 0;
484 }
485
486 static const struct file_operations sel_policy_ops = {
487         .open           = sel_open_policy,
488         .read           = sel_read_policy,
489         .mmap           = sel_mmap_policy,
490         .release        = sel_release_policy,
491         .llseek         = generic_file_llseek,
492 };
493
494 static void sel_remove_old_bool_data(unsigned int bool_num, char **bool_names,
495                                      int *bool_values)
496 {
497         u32 i;
498
499         /* bool_dir cleanup */
500         for (i = 0; i < bool_num; i++)
501                 kfree(bool_names[i]);
502         kfree(bool_names);
503         kfree(bool_values);
504 }
505
506 static int sel_make_policy_nodes(struct selinux_fs_info *fsi,
507                                 struct selinux_policy *newpolicy)
508 {
509         int ret = 0;
510         struct dentry *tmp_parent, *tmp_bool_dir, *tmp_class_dir, *old_dentry;
511         unsigned int tmp_bool_num, old_bool_num;
512         char **tmp_bool_names, **old_bool_names;
513         int *tmp_bool_values, *old_bool_values;
514         unsigned long tmp_ino = fsi->last_ino; /* Don't increment last_ino in this function */
515
516         tmp_parent = sel_make_disconnected_dir(fsi->sb, &tmp_ino);
517         if (IS_ERR(tmp_parent))
518                 return PTR_ERR(tmp_parent);
519
520         tmp_ino = fsi->bool_dir->d_inode->i_ino - 1; /* sel_make_dir will increment and set */
521         tmp_bool_dir = sel_make_dir(tmp_parent, BOOL_DIR_NAME, &tmp_ino);
522         if (IS_ERR(tmp_bool_dir)) {
523                 ret = PTR_ERR(tmp_bool_dir);
524                 goto out;
525         }
526
527         tmp_ino = fsi->class_dir->d_inode->i_ino - 1; /* sel_make_dir will increment and set */
528         tmp_class_dir = sel_make_dir(tmp_parent, CLASS_DIR_NAME, &tmp_ino);
529         if (IS_ERR(tmp_class_dir)) {
530                 ret = PTR_ERR(tmp_class_dir);
531                 goto out;
532         }
533
534         ret = sel_make_bools(newpolicy, tmp_bool_dir, &tmp_bool_num,
535                              &tmp_bool_names, &tmp_bool_values);
536         if (ret)
537                 goto out;
538
539         ret = sel_make_classes(newpolicy, tmp_class_dir,
540                                &fsi->last_class_ino);
541         if (ret)
542                 goto out;
543
544         /* booleans */
545         old_dentry = fsi->bool_dir;
546         lock_rename(tmp_bool_dir, old_dentry);
547         d_exchange(tmp_bool_dir, fsi->bool_dir);
548
549         old_bool_num = fsi->bool_num;
550         old_bool_names = fsi->bool_pending_names;
551         old_bool_values = fsi->bool_pending_values;
552
553         fsi->bool_num = tmp_bool_num;
554         fsi->bool_pending_names = tmp_bool_names;
555         fsi->bool_pending_values = tmp_bool_values;
556
557         sel_remove_old_bool_data(old_bool_num, old_bool_names, old_bool_values);
558
559         fsi->bool_dir = tmp_bool_dir;
560         unlock_rename(tmp_bool_dir, old_dentry);
561
562         /* classes */
563         old_dentry = fsi->class_dir;
564         lock_rename(tmp_class_dir, old_dentry);
565         d_exchange(tmp_class_dir, fsi->class_dir);
566         fsi->class_dir = tmp_class_dir;
567         unlock_rename(tmp_class_dir, old_dentry);
568
569 out:
570         /* Since the other temporary dirs are children of tmp_parent
571          * this will handle all the cleanup in the case of a failure before
572          * the swapover
573          */
574         sel_remove_entries(tmp_parent);
575         dput(tmp_parent); /* d_genocide() only handles the children */
576
577         return ret;
578 }
579
580 static ssize_t sel_write_load(struct file *file, const char __user *buf,
581                               size_t count, loff_t *ppos)
582
583 {
584         struct selinux_fs_info *fsi = file_inode(file)->i_sb->s_fs_info;
585         struct selinux_load_state load_state;
586         ssize_t length;
587         void *data = NULL;
588
589         mutex_lock(&selinux_state.policy_mutex);
590
591         length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
592                               SECCLASS_SECURITY, SECURITY__LOAD_POLICY, NULL);
593         if (length)
594                 goto out;
595
596         /* No partial writes. */
597         length = -EINVAL;
598         if (*ppos != 0)
599                 goto out;
600
601         length = -ENOMEM;
602         data = vmalloc(count);
603         if (!data)
604                 goto out;
605
606         length = -EFAULT;
607         if (copy_from_user(data, buf, count) != 0)
608                 goto out;
609
610         length = security_load_policy(data, count, &load_state);
611         if (length) {
612                 pr_warn_ratelimited("SELinux: failed to load policy\n");
613                 goto out;
614         }
615
616         length = sel_make_policy_nodes(fsi, load_state.policy);
617         if (length) {
618                 pr_warn_ratelimited("SELinux: failed to initialize selinuxfs\n");
619                 selinux_policy_cancel(&load_state);
620                 goto out;
621         }
622
623         selinux_policy_commit(&load_state);
624
625         length = count;
626
627         audit_log(audit_context(), GFP_KERNEL, AUDIT_MAC_POLICY_LOAD,
628                 "auid=%u ses=%u lsm=selinux res=1",
629                 from_kuid(&init_user_ns, audit_get_loginuid(current)),
630                 audit_get_sessionid(current));
631 out:
632         mutex_unlock(&selinux_state.policy_mutex);
633         vfree(data);
634         return length;
635 }
636
637 static const struct file_operations sel_load_ops = {
638         .write          = sel_write_load,
639         .llseek         = generic_file_llseek,
640 };
641
642 static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
643 {
644         char *canon = NULL;
645         u32 sid, len;
646         ssize_t length;
647
648         length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
649                               SECCLASS_SECURITY, SECURITY__CHECK_CONTEXT, NULL);
650         if (length)
651                 goto out;
652
653         length = security_context_to_sid(buf, size, &sid, GFP_KERNEL);
654         if (length)
655                 goto out;
656
657         length = security_sid_to_context(sid, &canon, &len);
658         if (length)
659                 goto out;
660
661         length = -ERANGE;
662         if (len > SIMPLE_TRANSACTION_LIMIT) {
663                 pr_err("SELinux: %s:  context size (%u) exceeds "
664                         "payload max\n", __func__, len);
665                 goto out;
666         }
667
668         memcpy(buf, canon, len);
669         length = len;
670 out:
671         kfree(canon);
672         return length;
673 }
674
675 static ssize_t sel_read_checkreqprot(struct file *filp, char __user *buf,
676                                      size_t count, loff_t *ppos)
677 {
678         char tmpbuf[TMPBUFLEN];
679         ssize_t length;
680
681         length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
682                            checkreqprot_get());
683         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
684 }
685
686 static ssize_t sel_write_checkreqprot(struct file *file, const char __user *buf,
687                                       size_t count, loff_t *ppos)
688 {
689         char *page;
690         ssize_t length;
691         unsigned int new_value;
692
693         length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
694                               SECCLASS_SECURITY, SECURITY__SETCHECKREQPROT,
695                               NULL);
696         if (length)
697                 return length;
698
699         if (count >= PAGE_SIZE)
700                 return -ENOMEM;
701
702         /* No partial writes. */
703         if (*ppos != 0)
704                 return -EINVAL;
705
706         page = memdup_user_nul(buf, count);
707         if (IS_ERR(page))
708                 return PTR_ERR(page);
709
710         if (sscanf(page, "%u", &new_value) != 1) {
711                 length = -EINVAL;
712                 goto out;
713         }
714         length = count;
715
716         if (new_value) {
717                 char comm[sizeof(current->comm)];
718
719                 memcpy(comm, current->comm, sizeof(comm));
720                 pr_err("SELinux: %s (%d) set checkreqprot to 1. This is no longer supported.\n",
721                        comm, current->pid);
722         }
723
724         selinux_ima_measure_state();
725
726 out:
727         kfree(page);
728         return length;
729 }
730 static const struct file_operations sel_checkreqprot_ops = {
731         .read           = sel_read_checkreqprot,
732         .write          = sel_write_checkreqprot,
733         .llseek         = generic_file_llseek,
734 };
735
736 static ssize_t sel_write_validatetrans(struct file *file,
737                                         const char __user *buf,
738                                         size_t count, loff_t *ppos)
739 {
740         char *oldcon = NULL, *newcon = NULL, *taskcon = NULL;
741         char *req = NULL;
742         u32 osid, nsid, tsid;
743         u16 tclass;
744         int rc;
745
746         rc = avc_has_perm(current_sid(), SECINITSID_SECURITY,
747                           SECCLASS_SECURITY, SECURITY__VALIDATE_TRANS, NULL);
748         if (rc)
749                 goto out;
750
751         rc = -ENOMEM;
752         if (count >= PAGE_SIZE)
753                 goto out;
754
755         /* No partial writes. */
756         rc = -EINVAL;
757         if (*ppos != 0)
758                 goto out;
759
760         req = memdup_user_nul(buf, count);
761         if (IS_ERR(req)) {
762                 rc = PTR_ERR(req);
763                 req = NULL;
764                 goto out;
765         }
766
767         rc = -ENOMEM;
768         oldcon = kzalloc(count + 1, GFP_KERNEL);
769         if (!oldcon)
770                 goto out;
771
772         newcon = kzalloc(count + 1, GFP_KERNEL);
773         if (!newcon)
774                 goto out;
775
776         taskcon = kzalloc(count + 1, GFP_KERNEL);
777         if (!taskcon)
778                 goto out;
779
780         rc = -EINVAL;
781         if (sscanf(req, "%s %s %hu %s", oldcon, newcon, &tclass, taskcon) != 4)
782                 goto out;
783
784         rc = security_context_str_to_sid(oldcon, &osid, GFP_KERNEL);
785         if (rc)
786                 goto out;
787
788         rc = security_context_str_to_sid(newcon, &nsid, GFP_KERNEL);
789         if (rc)
790                 goto out;
791
792         rc = security_context_str_to_sid(taskcon, &tsid, GFP_KERNEL);
793         if (rc)
794                 goto out;
795
796         rc = security_validate_transition_user(osid, nsid, tsid, tclass);
797         if (!rc)
798                 rc = count;
799 out:
800         kfree(req);
801         kfree(oldcon);
802         kfree(newcon);
803         kfree(taskcon);
804         return rc;
805 }
806
807 static const struct file_operations sel_transition_ops = {
808         .write          = sel_write_validatetrans,
809         .llseek         = generic_file_llseek,
810 };
811
812 /*
813  * Remaining nodes use transaction based IO methods like nfsd/nfsctl.c
814  */
815 static ssize_t sel_write_access(struct file *file, char *buf, size_t size);
816 static ssize_t sel_write_create(struct file *file, char *buf, size_t size);
817 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size);
818 static ssize_t sel_write_user(struct file *file, char *buf, size_t size);
819 static ssize_t sel_write_member(struct file *file, char *buf, size_t size);
820
821 static ssize_t (*const write_op[])(struct file *, char *, size_t) = {
822         [SEL_ACCESS] = sel_write_access,
823         [SEL_CREATE] = sel_write_create,
824         [SEL_RELABEL] = sel_write_relabel,
825         [SEL_USER] = sel_write_user,
826         [SEL_MEMBER] = sel_write_member,
827         [SEL_CONTEXT] = sel_write_context,
828 };
829
830 static ssize_t selinux_transaction_write(struct file *file, const char __user *buf, size_t size, loff_t *pos)
831 {
832         ino_t ino = file_inode(file)->i_ino;
833         char *data;
834         ssize_t rv;
835
836         if (ino >= ARRAY_SIZE(write_op) || !write_op[ino])
837                 return -EINVAL;
838
839         data = simple_transaction_get(file, buf, size);
840         if (IS_ERR(data))
841                 return PTR_ERR(data);
842
843         rv = write_op[ino](file, data, size);
844         if (rv > 0) {
845                 simple_transaction_set(file, rv);
846                 rv = size;
847         }
848         return rv;
849 }
850
851 static const struct file_operations transaction_ops = {
852         .write          = selinux_transaction_write,
853         .read           = simple_transaction_read,
854         .release        = simple_transaction_release,
855         .llseek         = generic_file_llseek,
856 };
857
858 /*
859  * payload - write methods
860  * If the method has a response, the response should be put in buf,
861  * and the length returned.  Otherwise return 0 or and -error.
862  */
863
864 static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
865 {
866         char *scon = NULL, *tcon = NULL;
867         u32 ssid, tsid;
868         u16 tclass;
869         struct av_decision avd;
870         ssize_t length;
871
872         length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
873                               SECCLASS_SECURITY, SECURITY__COMPUTE_AV, NULL);
874         if (length)
875                 goto out;
876
877         length = -ENOMEM;
878         scon = kzalloc(size + 1, GFP_KERNEL);
879         if (!scon)
880                 goto out;
881
882         length = -ENOMEM;
883         tcon = kzalloc(size + 1, GFP_KERNEL);
884         if (!tcon)
885                 goto out;
886
887         length = -EINVAL;
888         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
889                 goto out;
890
891         length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL);
892         if (length)
893                 goto out;
894
895         length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
896         if (length)
897                 goto out;
898
899         security_compute_av_user(ssid, tsid, tclass, &avd);
900
901         length = scnprintf(buf, SIMPLE_TRANSACTION_LIMIT,
902                           "%x %x %x %x %u %x",
903                           avd.allowed, 0xffffffff,
904                           avd.auditallow, avd.auditdeny,
905                           avd.seqno, avd.flags);
906 out:
907         kfree(tcon);
908         kfree(scon);
909         return length;
910 }
911
912 static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
913 {
914         char *scon = NULL, *tcon = NULL;
915         char *namebuf = NULL, *objname = NULL;
916         u32 ssid, tsid, newsid;
917         u16 tclass;
918         ssize_t length;
919         char *newcon = NULL;
920         u32 len;
921         int nargs;
922
923         length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
924                               SECCLASS_SECURITY, SECURITY__COMPUTE_CREATE,
925                               NULL);
926         if (length)
927                 goto out;
928
929         length = -ENOMEM;
930         scon = kzalloc(size + 1, GFP_KERNEL);
931         if (!scon)
932                 goto out;
933
934         length = -ENOMEM;
935         tcon = kzalloc(size + 1, GFP_KERNEL);
936         if (!tcon)
937                 goto out;
938
939         length = -ENOMEM;
940         namebuf = kzalloc(size + 1, GFP_KERNEL);
941         if (!namebuf)
942                 goto out;
943
944         length = -EINVAL;
945         nargs = sscanf(buf, "%s %s %hu %s", scon, tcon, &tclass, namebuf);
946         if (nargs < 3 || nargs > 4)
947                 goto out;
948         if (nargs == 4) {
949                 /*
950                  * If and when the name of new object to be queried contains
951                  * either whitespace or multibyte characters, they shall be
952                  * encoded based on the percentage-encoding rule.
953                  * If not encoded, the sscanf logic picks up only left-half
954                  * of the supplied name; splitted by a whitespace unexpectedly.
955                  */
956                 char   *r, *w;
957                 int     c1, c2;
958
959                 r = w = namebuf;
960                 do {
961                         c1 = *r++;
962                         if (c1 == '+')
963                                 c1 = ' ';
964                         else if (c1 == '%') {
965                                 c1 = hex_to_bin(*r++);
966                                 if (c1 < 0)
967                                         goto out;
968                                 c2 = hex_to_bin(*r++);
969                                 if (c2 < 0)
970                                         goto out;
971                                 c1 = (c1 << 4) | c2;
972                         }
973                         *w++ = c1;
974                 } while (c1 != '\0');
975
976                 objname = namebuf;
977         }
978
979         length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL);
980         if (length)
981                 goto out;
982
983         length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
984         if (length)
985                 goto out;
986
987         length = security_transition_sid_user(ssid, tsid, tclass,
988                                               objname, &newsid);
989         if (length)
990                 goto out;
991
992         length = security_sid_to_context(newsid, &newcon, &len);
993         if (length)
994                 goto out;
995
996         length = -ERANGE;
997         if (len > SIMPLE_TRANSACTION_LIMIT) {
998                 pr_err("SELinux: %s:  context size (%u) exceeds "
999                         "payload max\n", __func__, len);
1000                 goto out;
1001         }
1002
1003         memcpy(buf, newcon, len);
1004         length = len;
1005 out:
1006         kfree(newcon);
1007         kfree(namebuf);
1008         kfree(tcon);
1009         kfree(scon);
1010         return length;
1011 }
1012
1013 static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
1014 {
1015         char *scon = NULL, *tcon = NULL;
1016         u32 ssid, tsid, newsid;
1017         u16 tclass;
1018         ssize_t length;
1019         char *newcon = NULL;
1020         u32 len;
1021
1022         length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
1023                               SECCLASS_SECURITY, SECURITY__COMPUTE_RELABEL,
1024                               NULL);
1025         if (length)
1026                 goto out;
1027
1028         length = -ENOMEM;
1029         scon = kzalloc(size + 1, GFP_KERNEL);
1030         if (!scon)
1031                 goto out;
1032
1033         length = -ENOMEM;
1034         tcon = kzalloc(size + 1, GFP_KERNEL);
1035         if (!tcon)
1036                 goto out;
1037
1038         length = -EINVAL;
1039         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
1040                 goto out;
1041
1042         length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL);
1043         if (length)
1044                 goto out;
1045
1046         length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
1047         if (length)
1048                 goto out;
1049
1050         length = security_change_sid(ssid, tsid, tclass, &newsid);
1051         if (length)
1052                 goto out;
1053
1054         length = security_sid_to_context(newsid, &newcon, &len);
1055         if (length)
1056                 goto out;
1057
1058         length = -ERANGE;
1059         if (len > SIMPLE_TRANSACTION_LIMIT)
1060                 goto out;
1061
1062         memcpy(buf, newcon, len);
1063         length = len;
1064 out:
1065         kfree(newcon);
1066         kfree(tcon);
1067         kfree(scon);
1068         return length;
1069 }
1070
1071 static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
1072 {
1073         char *con = NULL, *user = NULL, *ptr;
1074         u32 sid, *sids = NULL;
1075         ssize_t length;
1076         char *newcon;
1077         int i, rc;
1078         u32 len, nsids;
1079
1080         length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
1081                               SECCLASS_SECURITY, SECURITY__COMPUTE_USER,
1082                               NULL);
1083         if (length)
1084                 goto out;
1085
1086         length = -ENOMEM;
1087         con = kzalloc(size + 1, GFP_KERNEL);
1088         if (!con)
1089                 goto out;
1090
1091         length = -ENOMEM;
1092         user = kzalloc(size + 1, GFP_KERNEL);
1093         if (!user)
1094                 goto out;
1095
1096         length = -EINVAL;
1097         if (sscanf(buf, "%s %s", con, user) != 2)
1098                 goto out;
1099
1100         length = security_context_str_to_sid(con, &sid, GFP_KERNEL);
1101         if (length)
1102                 goto out;
1103
1104         length = security_get_user_sids(sid, user, &sids, &nsids);
1105         if (length)
1106                 goto out;
1107
1108         length = sprintf(buf, "%u", nsids) + 1;
1109         ptr = buf + length;
1110         for (i = 0; i < nsids; i++) {
1111                 rc = security_sid_to_context(sids[i], &newcon, &len);
1112                 if (rc) {
1113                         length = rc;
1114                         goto out;
1115                 }
1116                 if ((length + len) >= SIMPLE_TRANSACTION_LIMIT) {
1117                         kfree(newcon);
1118                         length = -ERANGE;
1119                         goto out;
1120                 }
1121                 memcpy(ptr, newcon, len);
1122                 kfree(newcon);
1123                 ptr += len;
1124                 length += len;
1125         }
1126 out:
1127         kfree(sids);
1128         kfree(user);
1129         kfree(con);
1130         return length;
1131 }
1132
1133 static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
1134 {
1135         char *scon = NULL, *tcon = NULL;
1136         u32 ssid, tsid, newsid;
1137         u16 tclass;
1138         ssize_t length;
1139         char *newcon = NULL;
1140         u32 len;
1141
1142         length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
1143                               SECCLASS_SECURITY, SECURITY__COMPUTE_MEMBER,
1144                               NULL);
1145         if (length)
1146                 goto out;
1147
1148         length = -ENOMEM;
1149         scon = kzalloc(size + 1, GFP_KERNEL);
1150         if (!scon)
1151                 goto out;
1152
1153         length = -ENOMEM;
1154         tcon = kzalloc(size + 1, GFP_KERNEL);
1155         if (!tcon)
1156                 goto out;
1157
1158         length = -EINVAL;
1159         if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
1160                 goto out;
1161
1162         length = security_context_str_to_sid(scon, &ssid, GFP_KERNEL);
1163         if (length)
1164                 goto out;
1165
1166         length = security_context_str_to_sid(tcon, &tsid, GFP_KERNEL);
1167         if (length)
1168                 goto out;
1169
1170         length = security_member_sid(ssid, tsid, tclass, &newsid);
1171         if (length)
1172                 goto out;
1173
1174         length = security_sid_to_context(newsid, &newcon, &len);
1175         if (length)
1176                 goto out;
1177
1178         length = -ERANGE;
1179         if (len > SIMPLE_TRANSACTION_LIMIT) {
1180                 pr_err("SELinux: %s:  context size (%u) exceeds "
1181                         "payload max\n", __func__, len);
1182                 goto out;
1183         }
1184
1185         memcpy(buf, newcon, len);
1186         length = len;
1187 out:
1188         kfree(newcon);
1189         kfree(tcon);
1190         kfree(scon);
1191         return length;
1192 }
1193
1194 static struct inode *sel_make_inode(struct super_block *sb, int mode)
1195 {
1196         struct inode *ret = new_inode(sb);
1197
1198         if (ret) {
1199                 ret->i_mode = mode;
1200                 ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret);
1201         }
1202         return ret;
1203 }
1204
1205 static ssize_t sel_read_bool(struct file *filep, char __user *buf,
1206                              size_t count, loff_t *ppos)
1207 {
1208         struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1209         char *page = NULL;
1210         ssize_t length;
1211         ssize_t ret;
1212         int cur_enforcing;
1213         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1214         const char *name = filep->f_path.dentry->d_name.name;
1215
1216         mutex_lock(&selinux_state.policy_mutex);
1217
1218         ret = -EINVAL;
1219         if (index >= fsi->bool_num || strcmp(name,
1220                                              fsi->bool_pending_names[index]))
1221                 goto out_unlock;
1222
1223         ret = -ENOMEM;
1224         page = (char *)get_zeroed_page(GFP_KERNEL);
1225         if (!page)
1226                 goto out_unlock;
1227
1228         cur_enforcing = security_get_bool_value(index);
1229         if (cur_enforcing < 0) {
1230                 ret = cur_enforcing;
1231                 goto out_unlock;
1232         }
1233         length = scnprintf(page, PAGE_SIZE, "%d %d", cur_enforcing,
1234                           fsi->bool_pending_values[index]);
1235         mutex_unlock(&selinux_state.policy_mutex);
1236         ret = simple_read_from_buffer(buf, count, ppos, page, length);
1237 out_free:
1238         free_page((unsigned long)page);
1239         return ret;
1240
1241 out_unlock:
1242         mutex_unlock(&selinux_state.policy_mutex);
1243         goto out_free;
1244 }
1245
1246 static ssize_t sel_write_bool(struct file *filep, const char __user *buf,
1247                               size_t count, loff_t *ppos)
1248 {
1249         struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1250         char *page = NULL;
1251         ssize_t length;
1252         int new_value;
1253         unsigned index = file_inode(filep)->i_ino & SEL_INO_MASK;
1254         const char *name = filep->f_path.dentry->d_name.name;
1255
1256         if (count >= PAGE_SIZE)
1257                 return -ENOMEM;
1258
1259         /* No partial writes. */
1260         if (*ppos != 0)
1261                 return -EINVAL;
1262
1263         page = memdup_user_nul(buf, count);
1264         if (IS_ERR(page))
1265                 return PTR_ERR(page);
1266
1267         mutex_lock(&selinux_state.policy_mutex);
1268
1269         length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
1270                               SECCLASS_SECURITY, SECURITY__SETBOOL,
1271                               NULL);
1272         if (length)
1273                 goto out;
1274
1275         length = -EINVAL;
1276         if (index >= fsi->bool_num || strcmp(name,
1277                                              fsi->bool_pending_names[index]))
1278                 goto out;
1279
1280         length = -EINVAL;
1281         if (sscanf(page, "%d", &new_value) != 1)
1282                 goto out;
1283
1284         if (new_value)
1285                 new_value = 1;
1286
1287         fsi->bool_pending_values[index] = new_value;
1288         length = count;
1289
1290 out:
1291         mutex_unlock(&selinux_state.policy_mutex);
1292         kfree(page);
1293         return length;
1294 }
1295
1296 static const struct file_operations sel_bool_ops = {
1297         .read           = sel_read_bool,
1298         .write          = sel_write_bool,
1299         .llseek         = generic_file_llseek,
1300 };
1301
1302 static ssize_t sel_commit_bools_write(struct file *filep,
1303                                       const char __user *buf,
1304                                       size_t count, loff_t *ppos)
1305 {
1306         struct selinux_fs_info *fsi = file_inode(filep)->i_sb->s_fs_info;
1307         char *page = NULL;
1308         ssize_t length;
1309         int new_value;
1310
1311         if (count >= PAGE_SIZE)
1312                 return -ENOMEM;
1313
1314         /* No partial writes. */
1315         if (*ppos != 0)
1316                 return -EINVAL;
1317
1318         page = memdup_user_nul(buf, count);
1319         if (IS_ERR(page))
1320                 return PTR_ERR(page);
1321
1322         mutex_lock(&selinux_state.policy_mutex);
1323
1324         length = avc_has_perm(current_sid(), SECINITSID_SECURITY,
1325                               SECCLASS_SECURITY, SECURITY__SETBOOL,
1326                               NULL);
1327         if (length)
1328                 goto out;
1329
1330         length = -EINVAL;
1331         if (sscanf(page, "%d", &new_value) != 1)
1332                 goto out;
1333
1334         length = 0;
1335         if (new_value && fsi->bool_pending_values)
1336                 length = security_set_bools(fsi->bool_num,
1337                                             fsi->bool_pending_values);
1338
1339         if (!length)
1340                 length = count;
1341
1342 out:
1343         mutex_unlock(&selinux_state.policy_mutex);
1344         kfree(page);
1345         return length;
1346 }
1347
1348 static const struct file_operations sel_commit_bools_ops = {
1349         .write          = sel_commit_bools_write,
1350         .llseek         = generic_file_llseek,
1351 };
1352
1353 static void sel_remove_entries(struct dentry *de)
1354 {
1355         d_genocide(de);
1356         shrink_dcache_parent(de);
1357 }
1358
1359 static int sel_make_bools(struct selinux_policy *newpolicy, struct dentry *bool_dir,
1360                           unsigned int *bool_num, char ***bool_pending_names,
1361                           int **bool_pending_values)
1362 {
1363         int ret;
1364         ssize_t len;
1365         struct dentry *dentry = NULL;
1366         struct inode *inode = NULL;
1367         struct inode_security_struct *isec;
1368         char **names = NULL, *page;
1369         u32 i, num;
1370         int *values = NULL;
1371         u32 sid;
1372
1373         ret = -ENOMEM;
1374         page = (char *)get_zeroed_page(GFP_KERNEL);
1375         if (!page)
1376                 goto out;
1377
1378         ret = security_get_bools(newpolicy, &num, &names, &values);
1379         if (ret)
1380                 goto out;
1381
1382         for (i = 0; i < num; i++) {
1383                 ret = -ENOMEM;
1384                 dentry = d_alloc_name(bool_dir, names[i]);
1385                 if (!dentry)
1386                         goto out;
1387
1388                 ret = -ENOMEM;
1389                 inode = sel_make_inode(bool_dir->d_sb, S_IFREG | S_IRUGO | S_IWUSR);
1390                 if (!inode) {
1391                         dput(dentry);
1392                         goto out;
1393                 }
1394
1395                 ret = -ENAMETOOLONG;
1396                 len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
1397                 if (len >= PAGE_SIZE) {
1398                         dput(dentry);
1399                         iput(inode);
1400                         goto out;
1401                 }
1402
1403                 isec = selinux_inode(inode);
1404                 ret = selinux_policy_genfs_sid(newpolicy, "selinuxfs", page,
1405                                          SECCLASS_FILE, &sid);
1406                 if (ret) {
1407                         pr_warn_ratelimited("SELinux: no sid found, defaulting to security isid for %s\n",
1408                                            page);
1409                         sid = SECINITSID_SECURITY;
1410                 }
1411
1412                 isec->sid = sid;
1413                 isec->initialized = LABEL_INITIALIZED;
1414                 inode->i_fop = &sel_bool_ops;
1415                 inode->i_ino = i|SEL_BOOL_INO_OFFSET;
1416                 d_add(dentry, inode);
1417         }
1418         *bool_num = num;
1419         *bool_pending_names = names;
1420         *bool_pending_values = values;
1421
1422         free_page((unsigned long)page);
1423         return 0;
1424 out:
1425         free_page((unsigned long)page);
1426
1427         if (names) {
1428                 for (i = 0; i < num; i++)
1429                         kfree(names[i]);
1430                 kfree(names);
1431         }
1432         kfree(values);
1433         sel_remove_entries(bool_dir);
1434
1435         return ret;
1436 }
1437
1438 static ssize_t sel_read_avc_cache_threshold(struct file *filp, char __user *buf,
1439                                             size_t count, loff_t *ppos)
1440 {
1441         char tmpbuf[TMPBUFLEN];
1442         ssize_t length;
1443
1444         length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
1445                            avc_get_cache_threshold());
1446         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1447 }
1448
1449 static ssize_t sel_write_avc_cache_threshold(struct file *file,
1450                                              const char __user *buf,
1451                                              size_t count, loff_t *ppos)
1452
1453 {
1454         char *page;
1455         ssize_t ret;
1456         unsigned int new_value;
1457
1458         ret = avc_has_perm(current_sid(), SECINITSID_SECURITY,
1459                            SECCLASS_SECURITY, SECURITY__SETSECPARAM,
1460                            NULL);
1461         if (ret)
1462                 return ret;
1463
1464         if (count >= PAGE_SIZE)
1465                 return -ENOMEM;
1466
1467         /* No partial writes. */
1468         if (*ppos != 0)
1469                 return -EINVAL;
1470
1471         page = memdup_user_nul(buf, count);
1472         if (IS_ERR(page))
1473                 return PTR_ERR(page);
1474
1475         ret = -EINVAL;
1476         if (sscanf(page, "%u", &new_value) != 1)
1477                 goto out;
1478
1479         avc_set_cache_threshold(new_value);
1480
1481         ret = count;
1482 out:
1483         kfree(page);
1484         return ret;
1485 }
1486
1487 static ssize_t sel_read_avc_hash_stats(struct file *filp, char __user *buf,
1488                                        size_t count, loff_t *ppos)
1489 {
1490         char *page;
1491         ssize_t length;
1492
1493         page = (char *)__get_free_page(GFP_KERNEL);
1494         if (!page)
1495                 return -ENOMEM;
1496
1497         length = avc_get_hash_stats(page);
1498         if (length >= 0)
1499                 length = simple_read_from_buffer(buf, count, ppos, page, length);
1500         free_page((unsigned long)page);
1501
1502         return length;
1503 }
1504
1505 static ssize_t sel_read_sidtab_hash_stats(struct file *filp, char __user *buf,
1506                                         size_t count, loff_t *ppos)
1507 {
1508         char *page;
1509         ssize_t length;
1510
1511         page = (char *)__get_free_page(GFP_KERNEL);
1512         if (!page)
1513                 return -ENOMEM;
1514
1515         length = security_sidtab_hash_stats(page);
1516         if (length >= 0)
1517                 length = simple_read_from_buffer(buf, count, ppos, page,
1518                                                 length);
1519         free_page((unsigned long)page);
1520
1521         return length;
1522 }
1523
1524 static const struct file_operations sel_sidtab_hash_stats_ops = {
1525         .read           = sel_read_sidtab_hash_stats,
1526         .llseek         = generic_file_llseek,
1527 };
1528
1529 static const struct file_operations sel_avc_cache_threshold_ops = {
1530         .read           = sel_read_avc_cache_threshold,
1531         .write          = sel_write_avc_cache_threshold,
1532         .llseek         = generic_file_llseek,
1533 };
1534
1535 static const struct file_operations sel_avc_hash_stats_ops = {
1536         .read           = sel_read_avc_hash_stats,
1537         .llseek         = generic_file_llseek,
1538 };
1539
1540 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1541 static struct avc_cache_stats *sel_avc_get_stat_idx(loff_t *idx)
1542 {
1543         int cpu;
1544
1545         for (cpu = *idx; cpu < nr_cpu_ids; ++cpu) {
1546                 if (!cpu_possible(cpu))
1547                         continue;
1548                 *idx = cpu + 1;
1549                 return &per_cpu(avc_cache_stats, cpu);
1550         }
1551         (*idx)++;
1552         return NULL;
1553 }
1554
1555 static void *sel_avc_stats_seq_start(struct seq_file *seq, loff_t *pos)
1556 {
1557         loff_t n = *pos - 1;
1558
1559         if (*pos == 0)
1560                 return SEQ_START_TOKEN;
1561
1562         return sel_avc_get_stat_idx(&n);
1563 }
1564
1565 static void *sel_avc_stats_seq_next(struct seq_file *seq, void *v, loff_t *pos)
1566 {
1567         return sel_avc_get_stat_idx(pos);
1568 }
1569
1570 static int sel_avc_stats_seq_show(struct seq_file *seq, void *v)
1571 {
1572         struct avc_cache_stats *st = v;
1573
1574         if (v == SEQ_START_TOKEN) {
1575                 seq_puts(seq,
1576                          "lookups hits misses allocations reclaims frees\n");
1577         } else {
1578                 unsigned int lookups = st->lookups;
1579                 unsigned int misses = st->misses;
1580                 unsigned int hits = lookups - misses;
1581                 seq_printf(seq, "%u %u %u %u %u %u\n", lookups,
1582                            hits, misses, st->allocations,
1583                            st->reclaims, st->frees);
1584         }
1585         return 0;
1586 }
1587
1588 static void sel_avc_stats_seq_stop(struct seq_file *seq, void *v)
1589 { }
1590
1591 static const struct seq_operations sel_avc_cache_stats_seq_ops = {
1592         .start          = sel_avc_stats_seq_start,
1593         .next           = sel_avc_stats_seq_next,
1594         .show           = sel_avc_stats_seq_show,
1595         .stop           = sel_avc_stats_seq_stop,
1596 };
1597
1598 static int sel_open_avc_cache_stats(struct inode *inode, struct file *file)
1599 {
1600         return seq_open(file, &sel_avc_cache_stats_seq_ops);
1601 }
1602
1603 static const struct file_operations sel_avc_cache_stats_ops = {
1604         .open           = sel_open_avc_cache_stats,
1605         .read           = seq_read,
1606         .llseek         = seq_lseek,
1607         .release        = seq_release,
1608 };
1609 #endif
1610
1611 static int sel_make_avc_files(struct dentry *dir)
1612 {
1613         struct super_block *sb = dir->d_sb;
1614         struct selinux_fs_info *fsi = sb->s_fs_info;
1615         int i;
1616         static const struct tree_descr files[] = {
1617                 { "cache_threshold",
1618                   &sel_avc_cache_threshold_ops, S_IRUGO|S_IWUSR },
1619                 { "hash_stats", &sel_avc_hash_stats_ops, S_IRUGO },
1620 #ifdef CONFIG_SECURITY_SELINUX_AVC_STATS
1621                 { "cache_stats", &sel_avc_cache_stats_ops, S_IRUGO },
1622 #endif
1623         };
1624
1625         for (i = 0; i < ARRAY_SIZE(files); i++) {
1626                 struct inode *inode;
1627                 struct dentry *dentry;
1628
1629                 dentry = d_alloc_name(dir, files[i].name);
1630                 if (!dentry)
1631                         return -ENOMEM;
1632
1633                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1634                 if (!inode) {
1635                         dput(dentry);
1636                         return -ENOMEM;
1637                 }
1638
1639                 inode->i_fop = files[i].ops;
1640                 inode->i_ino = ++fsi->last_ino;
1641                 d_add(dentry, inode);
1642         }
1643
1644         return 0;
1645 }
1646
1647 static int sel_make_ss_files(struct dentry *dir)
1648 {
1649         struct super_block *sb = dir->d_sb;
1650         struct selinux_fs_info *fsi = sb->s_fs_info;
1651         int i;
1652         static struct tree_descr files[] = {
1653                 { "sidtab_hash_stats", &sel_sidtab_hash_stats_ops, S_IRUGO },
1654         };
1655
1656         for (i = 0; i < ARRAY_SIZE(files); i++) {
1657                 struct inode *inode;
1658                 struct dentry *dentry;
1659
1660                 dentry = d_alloc_name(dir, files[i].name);
1661                 if (!dentry)
1662                         return -ENOMEM;
1663
1664                 inode = sel_make_inode(dir->d_sb, S_IFREG|files[i].mode);
1665                 if (!inode) {
1666                         dput(dentry);
1667                         return -ENOMEM;
1668                 }
1669
1670                 inode->i_fop = files[i].ops;
1671                 inode->i_ino = ++fsi->last_ino;
1672                 d_add(dentry, inode);
1673         }
1674
1675         return 0;
1676 }
1677
1678 static ssize_t sel_read_initcon(struct file *file, char __user *buf,
1679                                 size_t count, loff_t *ppos)
1680 {
1681         char *con;
1682         u32 sid, len;
1683         ssize_t ret;
1684
1685         sid = file_inode(file)->i_ino&SEL_INO_MASK;
1686         ret = security_sid_to_context(sid, &con, &len);
1687         if (ret)
1688                 return ret;
1689
1690         ret = simple_read_from_buffer(buf, count, ppos, con, len);
1691         kfree(con);
1692         return ret;
1693 }
1694
1695 static const struct file_operations sel_initcon_ops = {
1696         .read           = sel_read_initcon,
1697         .llseek         = generic_file_llseek,
1698 };
1699
1700 static int sel_make_initcon_files(struct dentry *dir)
1701 {
1702         int i;
1703
1704         for (i = 1; i <= SECINITSID_NUM; i++) {
1705                 struct inode *inode;
1706                 struct dentry *dentry;
1707                 const char *s = security_get_initial_sid_context(i);
1708
1709                 if (!s)
1710                         continue;
1711                 dentry = d_alloc_name(dir, s);
1712                 if (!dentry)
1713                         return -ENOMEM;
1714
1715                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1716                 if (!inode) {
1717                         dput(dentry);
1718                         return -ENOMEM;
1719                 }
1720
1721                 inode->i_fop = &sel_initcon_ops;
1722                 inode->i_ino = i|SEL_INITCON_INO_OFFSET;
1723                 d_add(dentry, inode);
1724         }
1725
1726         return 0;
1727 }
1728
1729 static inline unsigned long sel_class_to_ino(u16 class)
1730 {
1731         return (class * (SEL_VEC_MAX + 1)) | SEL_CLASS_INO_OFFSET;
1732 }
1733
1734 static inline u16 sel_ino_to_class(unsigned long ino)
1735 {
1736         return (ino & SEL_INO_MASK) / (SEL_VEC_MAX + 1);
1737 }
1738
1739 static inline unsigned long sel_perm_to_ino(u16 class, u32 perm)
1740 {
1741         return (class * (SEL_VEC_MAX + 1) + perm) | SEL_CLASS_INO_OFFSET;
1742 }
1743
1744 static inline u32 sel_ino_to_perm(unsigned long ino)
1745 {
1746         return (ino & SEL_INO_MASK) % (SEL_VEC_MAX + 1);
1747 }
1748
1749 static ssize_t sel_read_class(struct file *file, char __user *buf,
1750                                 size_t count, loff_t *ppos)
1751 {
1752         unsigned long ino = file_inode(file)->i_ino;
1753         char res[TMPBUFLEN];
1754         ssize_t len = scnprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
1755         return simple_read_from_buffer(buf, count, ppos, res, len);
1756 }
1757
1758 static const struct file_operations sel_class_ops = {
1759         .read           = sel_read_class,
1760         .llseek         = generic_file_llseek,
1761 };
1762
1763 static ssize_t sel_read_perm(struct file *file, char __user *buf,
1764                                 size_t count, loff_t *ppos)
1765 {
1766         unsigned long ino = file_inode(file)->i_ino;
1767         char res[TMPBUFLEN];
1768         ssize_t len = scnprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
1769         return simple_read_from_buffer(buf, count, ppos, res, len);
1770 }
1771
1772 static const struct file_operations sel_perm_ops = {
1773         .read           = sel_read_perm,
1774         .llseek         = generic_file_llseek,
1775 };
1776
1777 static ssize_t sel_read_policycap(struct file *file, char __user *buf,
1778                                   size_t count, loff_t *ppos)
1779 {
1780         int value;
1781         char tmpbuf[TMPBUFLEN];
1782         ssize_t length;
1783         unsigned long i_ino = file_inode(file)->i_ino;
1784
1785         value = security_policycap_supported(i_ino & SEL_INO_MASK);
1786         length = scnprintf(tmpbuf, TMPBUFLEN, "%d", value);
1787
1788         return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
1789 }
1790
1791 static const struct file_operations sel_policycap_ops = {
1792         .read           = sel_read_policycap,
1793         .llseek         = generic_file_llseek,
1794 };
1795
1796 static int sel_make_perm_files(struct selinux_policy *newpolicy,
1797                         char *objclass, int classvalue,
1798                         struct dentry *dir)
1799 {
1800         int i, rc, nperms;
1801         char **perms;
1802
1803         rc = security_get_permissions(newpolicy, objclass, &perms, &nperms);
1804         if (rc)
1805                 return rc;
1806
1807         for (i = 0; i < nperms; i++) {
1808                 struct inode *inode;
1809                 struct dentry *dentry;
1810
1811                 rc = -ENOMEM;
1812                 dentry = d_alloc_name(dir, perms[i]);
1813                 if (!dentry)
1814                         goto out;
1815
1816                 rc = -ENOMEM;
1817                 inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1818                 if (!inode) {
1819                         dput(dentry);
1820                         goto out;
1821                 }
1822
1823                 inode->i_fop = &sel_perm_ops;
1824                 /* i+1 since perm values are 1-indexed */
1825                 inode->i_ino = sel_perm_to_ino(classvalue, i + 1);
1826                 d_add(dentry, inode);
1827         }
1828         rc = 0;
1829 out:
1830         for (i = 0; i < nperms; i++)
1831                 kfree(perms[i]);
1832         kfree(perms);
1833         return rc;
1834 }
1835
1836 static int sel_make_class_dir_entries(struct selinux_policy *newpolicy,
1837                                 char *classname, int index,
1838                                 struct dentry *dir)
1839 {
1840         struct super_block *sb = dir->d_sb;
1841         struct selinux_fs_info *fsi = sb->s_fs_info;
1842         struct dentry *dentry = NULL;
1843         struct inode *inode = NULL;
1844
1845         dentry = d_alloc_name(dir, "index");
1846         if (!dentry)
1847                 return -ENOMEM;
1848
1849         inode = sel_make_inode(dir->d_sb, S_IFREG|S_IRUGO);
1850         if (!inode) {
1851                 dput(dentry);
1852                 return -ENOMEM;
1853         }
1854
1855         inode->i_fop = &sel_class_ops;
1856         inode->i_ino = sel_class_to_ino(index);
1857         d_add(dentry, inode);
1858
1859         dentry = sel_make_dir(dir, "perms", &fsi->last_class_ino);
1860         if (IS_ERR(dentry))
1861                 return PTR_ERR(dentry);
1862
1863         return sel_make_perm_files(newpolicy, classname, index, dentry);
1864 }
1865
1866 static int sel_make_classes(struct selinux_policy *newpolicy,
1867                             struct dentry *class_dir,
1868                             unsigned long *last_class_ino)
1869 {
1870
1871         int rc, nclasses, i;
1872         char **classes;
1873
1874         rc = security_get_classes(newpolicy, &classes, &nclasses);
1875         if (rc)
1876                 return rc;
1877
1878         /* +2 since classes are 1-indexed */
1879         *last_class_ino = sel_class_to_ino(nclasses + 2);
1880
1881         for (i = 0; i < nclasses; i++) {
1882                 struct dentry *class_name_dir;
1883
1884                 class_name_dir = sel_make_dir(class_dir, classes[i],
1885                                               last_class_ino);
1886                 if (IS_ERR(class_name_dir)) {
1887                         rc = PTR_ERR(class_name_dir);
1888                         goto out;
1889                 }
1890
1891                 /* i+1 since class values are 1-indexed */
1892                 rc = sel_make_class_dir_entries(newpolicy, classes[i], i + 1,
1893                                 class_name_dir);
1894                 if (rc)
1895                         goto out;
1896         }
1897         rc = 0;
1898 out:
1899         for (i = 0; i < nclasses; i++)
1900                 kfree(classes[i]);
1901         kfree(classes);
1902         return rc;
1903 }
1904
1905 static int sel_make_policycap(struct selinux_fs_info *fsi)
1906 {
1907         unsigned int iter;
1908         struct dentry *dentry = NULL;
1909         struct inode *inode = NULL;
1910
1911         for (iter = 0; iter <= POLICYDB_CAP_MAX; iter++) {
1912                 if (iter < ARRAY_SIZE(selinux_policycap_names))
1913                         dentry = d_alloc_name(fsi->policycap_dir,
1914                                               selinux_policycap_names[iter]);
1915                 else
1916                         dentry = d_alloc_name(fsi->policycap_dir, "unknown");
1917
1918                 if (dentry == NULL)
1919                         return -ENOMEM;
1920
1921                 inode = sel_make_inode(fsi->sb, S_IFREG | 0444);
1922                 if (inode == NULL) {
1923                         dput(dentry);
1924                         return -ENOMEM;
1925                 }
1926
1927                 inode->i_fop = &sel_policycap_ops;
1928                 inode->i_ino = iter | SEL_POLICYCAP_INO_OFFSET;
1929                 d_add(dentry, inode);
1930         }
1931
1932         return 0;
1933 }
1934
1935 static struct dentry *sel_make_dir(struct dentry *dir, const char *name,
1936                         unsigned long *ino)
1937 {
1938         struct dentry *dentry = d_alloc_name(dir, name);
1939         struct inode *inode;
1940
1941         if (!dentry)
1942                 return ERR_PTR(-ENOMEM);
1943
1944         inode = sel_make_inode(dir->d_sb, S_IFDIR | S_IRUGO | S_IXUGO);
1945         if (!inode) {
1946                 dput(dentry);
1947                 return ERR_PTR(-ENOMEM);
1948         }
1949
1950         inode->i_op = &simple_dir_inode_operations;
1951         inode->i_fop = &simple_dir_operations;
1952         inode->i_ino = ++(*ino);
1953         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1954         inc_nlink(inode);
1955         d_add(dentry, inode);
1956         /* bump link count on parent directory, too */
1957         inc_nlink(d_inode(dir));
1958
1959         return dentry;
1960 }
1961
1962 static struct dentry *sel_make_disconnected_dir(struct super_block *sb,
1963                                                 unsigned long *ino)
1964 {
1965         struct inode *inode = sel_make_inode(sb, S_IFDIR | S_IRUGO | S_IXUGO);
1966
1967         if (!inode)
1968                 return ERR_PTR(-ENOMEM);
1969
1970         inode->i_op = &simple_dir_inode_operations;
1971         inode->i_fop = &simple_dir_operations;
1972         inode->i_ino = ++(*ino);
1973         /* directory inodes start off with i_nlink == 2 (for "." entry) */
1974         inc_nlink(inode);
1975         return d_obtain_alias(inode);
1976 }
1977
1978 #define NULL_FILE_NAME "null"
1979
1980 static int sel_fill_super(struct super_block *sb, struct fs_context *fc)
1981 {
1982         struct selinux_fs_info *fsi;
1983         int ret;
1984         struct dentry *dentry;
1985         struct inode *inode;
1986         struct inode_security_struct *isec;
1987
1988         static const struct tree_descr selinux_files[] = {
1989                 [SEL_LOAD] = {"load", &sel_load_ops, S_IRUSR|S_IWUSR},
1990                 [SEL_ENFORCE] = {"enforce", &sel_enforce_ops, S_IRUGO|S_IWUSR},
1991                 [SEL_CONTEXT] = {"context", &transaction_ops, S_IRUGO|S_IWUGO},
1992                 [SEL_ACCESS] = {"access", &transaction_ops, S_IRUGO|S_IWUGO},
1993                 [SEL_CREATE] = {"create", &transaction_ops, S_IRUGO|S_IWUGO},
1994                 [SEL_RELABEL] = {"relabel", &transaction_ops, S_IRUGO|S_IWUGO},
1995                 [SEL_USER] = {"user", &transaction_ops, S_IRUGO|S_IWUGO},
1996                 [SEL_POLICYVERS] = {"policyvers", &sel_policyvers_ops, S_IRUGO},
1997                 [SEL_COMMIT_BOOLS] = {"commit_pending_bools", &sel_commit_bools_ops, S_IWUSR},
1998                 [SEL_MLS] = {"mls", &sel_mls_ops, S_IRUGO},
1999                 [SEL_DISABLE] = {"disable", &sel_disable_ops, S_IWUSR},
2000                 [SEL_MEMBER] = {"member", &transaction_ops, S_IRUGO|S_IWUGO},
2001                 [SEL_CHECKREQPROT] = {"checkreqprot", &sel_checkreqprot_ops, S_IRUGO|S_IWUSR},
2002                 [SEL_REJECT_UNKNOWN] = {"reject_unknown", &sel_handle_unknown_ops, S_IRUGO},
2003                 [SEL_DENY_UNKNOWN] = {"deny_unknown", &sel_handle_unknown_ops, S_IRUGO},
2004                 [SEL_STATUS] = {"status", &sel_handle_status_ops, S_IRUGO},
2005                 [SEL_POLICY] = {"policy", &sel_policy_ops, S_IRUGO},
2006                 [SEL_VALIDATE_TRANS] = {"validatetrans", &sel_transition_ops,
2007                                         S_IWUGO},
2008                 /* last one */ {""}
2009         };
2010
2011         ret = selinux_fs_info_create(sb);
2012         if (ret)
2013                 goto err;
2014
2015         ret = simple_fill_super(sb, SELINUX_MAGIC, selinux_files);
2016         if (ret)
2017                 goto err;
2018
2019         fsi = sb->s_fs_info;
2020         fsi->bool_dir = sel_make_dir(sb->s_root, BOOL_DIR_NAME, &fsi->last_ino);
2021         if (IS_ERR(fsi->bool_dir)) {
2022                 ret = PTR_ERR(fsi->bool_dir);
2023                 fsi->bool_dir = NULL;
2024                 goto err;
2025         }
2026
2027         ret = -ENOMEM;
2028         dentry = d_alloc_name(sb->s_root, NULL_FILE_NAME);
2029         if (!dentry)
2030                 goto err;
2031
2032         ret = -ENOMEM;
2033         inode = sel_make_inode(sb, S_IFCHR | S_IRUGO | S_IWUGO);
2034         if (!inode) {
2035                 dput(dentry);
2036                 goto err;
2037         }
2038
2039         inode->i_ino = ++fsi->last_ino;
2040         isec = selinux_inode(inode);
2041         isec->sid = SECINITSID_DEVNULL;
2042         isec->sclass = SECCLASS_CHR_FILE;
2043         isec->initialized = LABEL_INITIALIZED;
2044
2045         init_special_inode(inode, S_IFCHR | S_IRUGO | S_IWUGO, MKDEV(MEM_MAJOR, 3));
2046         d_add(dentry, inode);
2047
2048         dentry = sel_make_dir(sb->s_root, "avc", &fsi->last_ino);
2049         if (IS_ERR(dentry)) {
2050                 ret = PTR_ERR(dentry);
2051                 goto err;
2052         }
2053
2054         ret = sel_make_avc_files(dentry);
2055         if (ret)
2056                 goto err;
2057
2058         dentry = sel_make_dir(sb->s_root, "ss", &fsi->last_ino);
2059         if (IS_ERR(dentry)) {
2060                 ret = PTR_ERR(dentry);
2061                 goto err;
2062         }
2063
2064         ret = sel_make_ss_files(dentry);
2065         if (ret)
2066                 goto err;
2067
2068         dentry = sel_make_dir(sb->s_root, "initial_contexts", &fsi->last_ino);
2069         if (IS_ERR(dentry)) {
2070                 ret = PTR_ERR(dentry);
2071                 goto err;
2072         }
2073
2074         ret = sel_make_initcon_files(dentry);
2075         if (ret)
2076                 goto err;
2077
2078         fsi->class_dir = sel_make_dir(sb->s_root, CLASS_DIR_NAME, &fsi->last_ino);
2079         if (IS_ERR(fsi->class_dir)) {
2080                 ret = PTR_ERR(fsi->class_dir);
2081                 fsi->class_dir = NULL;
2082                 goto err;
2083         }
2084
2085         fsi->policycap_dir = sel_make_dir(sb->s_root, POLICYCAP_DIR_NAME,
2086                                           &fsi->last_ino);
2087         if (IS_ERR(fsi->policycap_dir)) {
2088                 ret = PTR_ERR(fsi->policycap_dir);
2089                 fsi->policycap_dir = NULL;
2090                 goto err;
2091         }
2092
2093         ret = sel_make_policycap(fsi);
2094         if (ret) {
2095                 pr_err("SELinux: failed to load policy capabilities\n");
2096                 goto err;
2097         }
2098
2099         return 0;
2100 err:
2101         pr_err("SELinux: %s:  failed while creating inodes\n",
2102                 __func__);
2103
2104         selinux_fs_info_free(sb);
2105
2106         return ret;
2107 }
2108
2109 static int sel_get_tree(struct fs_context *fc)
2110 {
2111         return get_tree_single(fc, sel_fill_super);
2112 }
2113
2114 static const struct fs_context_operations sel_context_ops = {
2115         .get_tree       = sel_get_tree,
2116 };
2117
2118 static int sel_init_fs_context(struct fs_context *fc)
2119 {
2120         fc->ops = &sel_context_ops;
2121         return 0;
2122 }
2123
2124 static void sel_kill_sb(struct super_block *sb)
2125 {
2126         selinux_fs_info_free(sb);
2127         kill_litter_super(sb);
2128 }
2129
2130 static struct file_system_type sel_fs_type = {
2131         .name           = "selinuxfs",
2132         .init_fs_context = sel_init_fs_context,
2133         .kill_sb        = sel_kill_sb,
2134 };
2135
2136 static struct vfsmount *selinuxfs_mount __ro_after_init;
2137 struct path selinux_null __ro_after_init;
2138
2139 static int __init init_sel_fs(void)
2140 {
2141         struct qstr null_name = QSTR_INIT(NULL_FILE_NAME,
2142                                           sizeof(NULL_FILE_NAME)-1);
2143         int err;
2144
2145         if (!selinux_enabled_boot)
2146                 return 0;
2147
2148         err = sysfs_create_mount_point(fs_kobj, "selinux");
2149         if (err)
2150                 return err;
2151
2152         err = register_filesystem(&sel_fs_type);
2153         if (err) {
2154                 sysfs_remove_mount_point(fs_kobj, "selinux");
2155                 return err;
2156         }
2157
2158         selinux_null.mnt = selinuxfs_mount = kern_mount(&sel_fs_type);
2159         if (IS_ERR(selinuxfs_mount)) {
2160                 pr_err("selinuxfs:  could not mount!\n");
2161                 err = PTR_ERR(selinuxfs_mount);
2162                 selinuxfs_mount = NULL;
2163         }
2164         selinux_null.dentry = d_hash_and_lookup(selinux_null.mnt->mnt_root,
2165                                                 &null_name);
2166         if (IS_ERR(selinux_null.dentry)) {
2167                 pr_err("selinuxfs:  could not lookup null!\n");
2168                 err = PTR_ERR(selinux_null.dentry);
2169                 selinux_null.dentry = NULL;
2170         }
2171
2172         return err;
2173 }
2174
2175 __initcall(init_sel_fs);