CRED: Separate task security context from task_struct
[linux-3.10.git] / security / selinux / hooks.c
1 /*
2  *  NSA Security-Enhanced Linux (SELinux) security module
3  *
4  *  This file contains the SELinux hook function implementations.
5  *
6  *  Authors:  Stephen Smalley, <sds@epoch.ncsc.mil>
7  *            Chris Vance, <cvance@nai.com>
8  *            Wayne Salamon, <wsalamon@nai.com>
9  *            James Morris <jmorris@redhat.com>
10  *
11  *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
12  *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
13  *                                         Eric Paris <eparis@redhat.com>
14  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
15  *                          <dgoeddel@trustedcs.com>
16  *  Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
17  *              Paul Moore <paul.moore@hp.com>
18  *  Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
19  *                     Yuichi Nakamura <ynakam@hitachisoft.jp>
20  *
21  *      This program is free software; you can redistribute it and/or modify
22  *      it under the terms of the GNU General Public License version 2,
23  *      as published by the Free Software Foundation.
24  */
25
26 #include <linux/init.h>
27 #include <linux/kernel.h>
28 #include <linux/tracehook.h>
29 #include <linux/errno.h>
30 #include <linux/sched.h>
31 #include <linux/security.h>
32 #include <linux/xattr.h>
33 #include <linux/capability.h>
34 #include <linux/unistd.h>
35 #include <linux/mm.h>
36 #include <linux/mman.h>
37 #include <linux/slab.h>
38 #include <linux/pagemap.h>
39 #include <linux/swap.h>
40 #include <linux/spinlock.h>
41 #include <linux/syscalls.h>
42 #include <linux/file.h>
43 #include <linux/fdtable.h>
44 #include <linux/namei.h>
45 #include <linux/mount.h>
46 #include <linux/proc_fs.h>
47 #include <linux/netfilter_ipv4.h>
48 #include <linux/netfilter_ipv6.h>
49 #include <linux/tty.h>
50 #include <net/icmp.h>
51 #include <net/ip.h>             /* for local_port_range[] */
52 #include <net/tcp.h>            /* struct or_callable used in sock_rcv_skb */
53 #include <net/net_namespace.h>
54 #include <net/netlabel.h>
55 #include <linux/uaccess.h>
56 #include <asm/ioctls.h>
57 #include <asm/atomic.h>
58 #include <linux/bitops.h>
59 #include <linux/interrupt.h>
60 #include <linux/netdevice.h>    /* for network interface checks */
61 #include <linux/netlink.h>
62 #include <linux/tcp.h>
63 #include <linux/udp.h>
64 #include <linux/dccp.h>
65 #include <linux/quota.h>
66 #include <linux/un.h>           /* for Unix socket types */
67 #include <net/af_unix.h>        /* for Unix socket types */
68 #include <linux/parser.h>
69 #include <linux/nfs_mount.h>
70 #include <net/ipv6.h>
71 #include <linux/hugetlb.h>
72 #include <linux/personality.h>
73 #include <linux/sysctl.h>
74 #include <linux/audit.h>
75 #include <linux/string.h>
76 #include <linux/selinux.h>
77 #include <linux/mutex.h>
78 #include <linux/posix-timers.h>
79
80 #include "avc.h"
81 #include "objsec.h"
82 #include "netif.h"
83 #include "netnode.h"
84 #include "netport.h"
85 #include "xfrm.h"
86 #include "netlabel.h"
87 #include "audit.h"
88
89 #define XATTR_SELINUX_SUFFIX "selinux"
90 #define XATTR_NAME_SELINUX XATTR_SECURITY_PREFIX XATTR_SELINUX_SUFFIX
91
92 #define NUM_SEL_MNT_OPTS 4
93
94 extern unsigned int policydb_loaded_version;
95 extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm);
96 extern int selinux_compat_net;
97 extern struct security_operations *security_ops;
98
99 /* SECMARK reference count */
100 atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
101
102 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
103 int selinux_enforcing;
104
105 static int __init enforcing_setup(char *str)
106 {
107         unsigned long enforcing;
108         if (!strict_strtoul(str, 0, &enforcing))
109                 selinux_enforcing = enforcing ? 1 : 0;
110         return 1;
111 }
112 __setup("enforcing=", enforcing_setup);
113 #endif
114
115 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
116 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
117
118 static int __init selinux_enabled_setup(char *str)
119 {
120         unsigned long enabled;
121         if (!strict_strtoul(str, 0, &enabled))
122                 selinux_enabled = enabled ? 1 : 0;
123         return 1;
124 }
125 __setup("selinux=", selinux_enabled_setup);
126 #else
127 int selinux_enabled = 1;
128 #endif
129
130
131 /*
132  * Minimal support for a secondary security module,
133  * just to allow the use of the capability module.
134  */
135 static struct security_operations *secondary_ops;
136
137 /* Lists of inode and superblock security structures initialized
138    before the policy was loaded. */
139 static LIST_HEAD(superblock_security_head);
140 static DEFINE_SPINLOCK(sb_security_lock);
141
142 static struct kmem_cache *sel_inode_cache;
143
144 /**
145  * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
146  *
147  * Description:
148  * This function checks the SECMARK reference counter to see if any SECMARK
149  * targets are currently configured, if the reference counter is greater than
150  * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
151  * enabled, false (0) if SECMARK is disabled.
152  *
153  */
154 static int selinux_secmark_enabled(void)
155 {
156         return (atomic_read(&selinux_secmark_refcount) > 0);
157 }
158
159 /* Allocate and free functions for each kind of security blob. */
160
161 static int task_alloc_security(struct task_struct *task)
162 {
163         struct task_security_struct *tsec;
164
165         tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
166         if (!tsec)
167                 return -ENOMEM;
168
169         tsec->osid = tsec->sid = SECINITSID_UNLABELED;
170         task->cred->security = tsec;
171
172         return 0;
173 }
174
175 static void task_free_security(struct task_struct *task)
176 {
177         struct task_security_struct *tsec = task->cred->security;
178         task->cred->security = NULL;
179         kfree(tsec);
180 }
181
182 static int inode_alloc_security(struct inode *inode)
183 {
184         struct task_security_struct *tsec = current->cred->security;
185         struct inode_security_struct *isec;
186
187         isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
188         if (!isec)
189                 return -ENOMEM;
190
191         mutex_init(&isec->lock);
192         INIT_LIST_HEAD(&isec->list);
193         isec->inode = inode;
194         isec->sid = SECINITSID_UNLABELED;
195         isec->sclass = SECCLASS_FILE;
196         isec->task_sid = tsec->sid;
197         inode->i_security = isec;
198
199         return 0;
200 }
201
202 static void inode_free_security(struct inode *inode)
203 {
204         struct inode_security_struct *isec = inode->i_security;
205         struct superblock_security_struct *sbsec = inode->i_sb->s_security;
206
207         spin_lock(&sbsec->isec_lock);
208         if (!list_empty(&isec->list))
209                 list_del_init(&isec->list);
210         spin_unlock(&sbsec->isec_lock);
211
212         inode->i_security = NULL;
213         kmem_cache_free(sel_inode_cache, isec);
214 }
215
216 static int file_alloc_security(struct file *file)
217 {
218         struct task_security_struct *tsec = current->cred->security;
219         struct file_security_struct *fsec;
220
221         fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
222         if (!fsec)
223                 return -ENOMEM;
224
225         fsec->sid = tsec->sid;
226         fsec->fown_sid = tsec->sid;
227         file->f_security = fsec;
228
229         return 0;
230 }
231
232 static void file_free_security(struct file *file)
233 {
234         struct file_security_struct *fsec = file->f_security;
235         file->f_security = NULL;
236         kfree(fsec);
237 }
238
239 static int superblock_alloc_security(struct super_block *sb)
240 {
241         struct superblock_security_struct *sbsec;
242
243         sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
244         if (!sbsec)
245                 return -ENOMEM;
246
247         mutex_init(&sbsec->lock);
248         INIT_LIST_HEAD(&sbsec->list);
249         INIT_LIST_HEAD(&sbsec->isec_head);
250         spin_lock_init(&sbsec->isec_lock);
251         sbsec->sb = sb;
252         sbsec->sid = SECINITSID_UNLABELED;
253         sbsec->def_sid = SECINITSID_FILE;
254         sbsec->mntpoint_sid = SECINITSID_UNLABELED;
255         sb->s_security = sbsec;
256
257         return 0;
258 }
259
260 static void superblock_free_security(struct super_block *sb)
261 {
262         struct superblock_security_struct *sbsec = sb->s_security;
263
264         spin_lock(&sb_security_lock);
265         if (!list_empty(&sbsec->list))
266                 list_del_init(&sbsec->list);
267         spin_unlock(&sb_security_lock);
268
269         sb->s_security = NULL;
270         kfree(sbsec);
271 }
272
273 static int sk_alloc_security(struct sock *sk, int family, gfp_t priority)
274 {
275         struct sk_security_struct *ssec;
276
277         ssec = kzalloc(sizeof(*ssec), priority);
278         if (!ssec)
279                 return -ENOMEM;
280
281         ssec->peer_sid = SECINITSID_UNLABELED;
282         ssec->sid = SECINITSID_UNLABELED;
283         sk->sk_security = ssec;
284
285         selinux_netlbl_sk_security_reset(ssec, family);
286
287         return 0;
288 }
289
290 static void sk_free_security(struct sock *sk)
291 {
292         struct sk_security_struct *ssec = sk->sk_security;
293
294         sk->sk_security = NULL;
295         selinux_netlbl_sk_security_free(ssec);
296         kfree(ssec);
297 }
298
299 /* The security server must be initialized before
300    any labeling or access decisions can be provided. */
301 extern int ss_initialized;
302
303 /* The file system's label must be initialized prior to use. */
304
305 static char *labeling_behaviors[6] = {
306         "uses xattr",
307         "uses transition SIDs",
308         "uses task SIDs",
309         "uses genfs_contexts",
310         "not configured for labeling",
311         "uses mountpoint labeling",
312 };
313
314 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
315
316 static inline int inode_doinit(struct inode *inode)
317 {
318         return inode_doinit_with_dentry(inode, NULL);
319 }
320
321 enum {
322         Opt_error = -1,
323         Opt_context = 1,
324         Opt_fscontext = 2,
325         Opt_defcontext = 3,
326         Opt_rootcontext = 4,
327 };
328
329 static const match_table_t tokens = {
330         {Opt_context, CONTEXT_STR "%s"},
331         {Opt_fscontext, FSCONTEXT_STR "%s"},
332         {Opt_defcontext, DEFCONTEXT_STR "%s"},
333         {Opt_rootcontext, ROOTCONTEXT_STR "%s"},
334         {Opt_error, NULL},
335 };
336
337 #define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"
338
339 static int may_context_mount_sb_relabel(u32 sid,
340                         struct superblock_security_struct *sbsec,
341                         struct task_security_struct *tsec)
342 {
343         int rc;
344
345         rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
346                           FILESYSTEM__RELABELFROM, NULL);
347         if (rc)
348                 return rc;
349
350         rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
351                           FILESYSTEM__RELABELTO, NULL);
352         return rc;
353 }
354
355 static int may_context_mount_inode_relabel(u32 sid,
356                         struct superblock_security_struct *sbsec,
357                         struct task_security_struct *tsec)
358 {
359         int rc;
360         rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
361                           FILESYSTEM__RELABELFROM, NULL);
362         if (rc)
363                 return rc;
364
365         rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
366                           FILESYSTEM__ASSOCIATE, NULL);
367         return rc;
368 }
369
370 static int sb_finish_set_opts(struct super_block *sb)
371 {
372         struct superblock_security_struct *sbsec = sb->s_security;
373         struct dentry *root = sb->s_root;
374         struct inode *root_inode = root->d_inode;
375         int rc = 0;
376
377         if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
378                 /* Make sure that the xattr handler exists and that no
379                    error other than -ENODATA is returned by getxattr on
380                    the root directory.  -ENODATA is ok, as this may be
381                    the first boot of the SELinux kernel before we have
382                    assigned xattr values to the filesystem. */
383                 if (!root_inode->i_op->getxattr) {
384                         printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
385                                "xattr support\n", sb->s_id, sb->s_type->name);
386                         rc = -EOPNOTSUPP;
387                         goto out;
388                 }
389                 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
390                 if (rc < 0 && rc != -ENODATA) {
391                         if (rc == -EOPNOTSUPP)
392                                 printk(KERN_WARNING "SELinux: (dev %s, type "
393                                        "%s) has no security xattr handler\n",
394                                        sb->s_id, sb->s_type->name);
395                         else
396                                 printk(KERN_WARNING "SELinux: (dev %s, type "
397                                        "%s) getxattr errno %d\n", sb->s_id,
398                                        sb->s_type->name, -rc);
399                         goto out;
400                 }
401         }
402
403         sbsec->initialized = 1;
404
405         if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
406                 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
407                        sb->s_id, sb->s_type->name);
408         else
409                 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
410                        sb->s_id, sb->s_type->name,
411                        labeling_behaviors[sbsec->behavior-1]);
412
413         /* Initialize the root inode. */
414         rc = inode_doinit_with_dentry(root_inode, root);
415
416         /* Initialize any other inodes associated with the superblock, e.g.
417            inodes created prior to initial policy load or inodes created
418            during get_sb by a pseudo filesystem that directly
419            populates itself. */
420         spin_lock(&sbsec->isec_lock);
421 next_inode:
422         if (!list_empty(&sbsec->isec_head)) {
423                 struct inode_security_struct *isec =
424                                 list_entry(sbsec->isec_head.next,
425                                            struct inode_security_struct, list);
426                 struct inode *inode = isec->inode;
427                 spin_unlock(&sbsec->isec_lock);
428                 inode = igrab(inode);
429                 if (inode) {
430                         if (!IS_PRIVATE(inode))
431                                 inode_doinit(inode);
432                         iput(inode);
433                 }
434                 spin_lock(&sbsec->isec_lock);
435                 list_del_init(&isec->list);
436                 goto next_inode;
437         }
438         spin_unlock(&sbsec->isec_lock);
439 out:
440         return rc;
441 }
442
443 /*
444  * This function should allow an FS to ask what it's mount security
445  * options were so it can use those later for submounts, displaying
446  * mount options, or whatever.
447  */
448 static int selinux_get_mnt_opts(const struct super_block *sb,
449                                 struct security_mnt_opts *opts)
450 {
451         int rc = 0, i;
452         struct superblock_security_struct *sbsec = sb->s_security;
453         char *context = NULL;
454         u32 len;
455         char tmp;
456
457         security_init_mnt_opts(opts);
458
459         if (!sbsec->initialized)
460                 return -EINVAL;
461
462         if (!ss_initialized)
463                 return -EINVAL;
464
465         /*
466          * if we ever use sbsec flags for anything other than tracking mount
467          * settings this is going to need a mask
468          */
469         tmp = sbsec->flags;
470         /* count the number of mount options for this sb */
471         for (i = 0; i < 8; i++) {
472                 if (tmp & 0x01)
473                         opts->num_mnt_opts++;
474                 tmp >>= 1;
475         }
476
477         opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
478         if (!opts->mnt_opts) {
479                 rc = -ENOMEM;
480                 goto out_free;
481         }
482
483         opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
484         if (!opts->mnt_opts_flags) {
485                 rc = -ENOMEM;
486                 goto out_free;
487         }
488
489         i = 0;
490         if (sbsec->flags & FSCONTEXT_MNT) {
491                 rc = security_sid_to_context(sbsec->sid, &context, &len);
492                 if (rc)
493                         goto out_free;
494                 opts->mnt_opts[i] = context;
495                 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
496         }
497         if (sbsec->flags & CONTEXT_MNT) {
498                 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
499                 if (rc)
500                         goto out_free;
501                 opts->mnt_opts[i] = context;
502                 opts->mnt_opts_flags[i++] = CONTEXT_MNT;
503         }
504         if (sbsec->flags & DEFCONTEXT_MNT) {
505                 rc = security_sid_to_context(sbsec->def_sid, &context, &len);
506                 if (rc)
507                         goto out_free;
508                 opts->mnt_opts[i] = context;
509                 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
510         }
511         if (sbsec->flags & ROOTCONTEXT_MNT) {
512                 struct inode *root = sbsec->sb->s_root->d_inode;
513                 struct inode_security_struct *isec = root->i_security;
514
515                 rc = security_sid_to_context(isec->sid, &context, &len);
516                 if (rc)
517                         goto out_free;
518                 opts->mnt_opts[i] = context;
519                 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
520         }
521
522         BUG_ON(i != opts->num_mnt_opts);
523
524         return 0;
525
526 out_free:
527         security_free_mnt_opts(opts);
528         return rc;
529 }
530
531 static int bad_option(struct superblock_security_struct *sbsec, char flag,
532                       u32 old_sid, u32 new_sid)
533 {
534         /* check if the old mount command had the same options */
535         if (sbsec->initialized)
536                 if (!(sbsec->flags & flag) ||
537                     (old_sid != new_sid))
538                         return 1;
539
540         /* check if we were passed the same options twice,
541          * aka someone passed context=a,context=b
542          */
543         if (!sbsec->initialized)
544                 if (sbsec->flags & flag)
545                         return 1;
546         return 0;
547 }
548
549 /*
550  * Allow filesystems with binary mount data to explicitly set mount point
551  * labeling information.
552  */
553 static int selinux_set_mnt_opts(struct super_block *sb,
554                                 struct security_mnt_opts *opts)
555 {
556         int rc = 0, i;
557         struct task_security_struct *tsec = current->cred->security;
558         struct superblock_security_struct *sbsec = sb->s_security;
559         const char *name = sb->s_type->name;
560         struct inode *inode = sbsec->sb->s_root->d_inode;
561         struct inode_security_struct *root_isec = inode->i_security;
562         u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
563         u32 defcontext_sid = 0;
564         char **mount_options = opts->mnt_opts;
565         int *flags = opts->mnt_opts_flags;
566         int num_opts = opts->num_mnt_opts;
567
568         mutex_lock(&sbsec->lock);
569
570         if (!ss_initialized) {
571                 if (!num_opts) {
572                         /* Defer initialization until selinux_complete_init,
573                            after the initial policy is loaded and the security
574                            server is ready to handle calls. */
575                         spin_lock(&sb_security_lock);
576                         if (list_empty(&sbsec->list))
577                                 list_add(&sbsec->list, &superblock_security_head);
578                         spin_unlock(&sb_security_lock);
579                         goto out;
580                 }
581                 rc = -EINVAL;
582                 printk(KERN_WARNING "SELinux: Unable to set superblock options "
583                         "before the security server is initialized\n");
584                 goto out;
585         }
586
587         /*
588          * Binary mount data FS will come through this function twice.  Once
589          * from an explicit call and once from the generic calls from the vfs.
590          * Since the generic VFS calls will not contain any security mount data
591          * we need to skip the double mount verification.
592          *
593          * This does open a hole in which we will not notice if the first
594          * mount using this sb set explict options and a second mount using
595          * this sb does not set any security options.  (The first options
596          * will be used for both mounts)
597          */
598         if (sbsec->initialized && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
599             && (num_opts == 0))
600                 goto out;
601
602         /*
603          * parse the mount options, check if they are valid sids.
604          * also check if someone is trying to mount the same sb more
605          * than once with different security options.
606          */
607         for (i = 0; i < num_opts; i++) {
608                 u32 sid;
609                 rc = security_context_to_sid(mount_options[i],
610                                              strlen(mount_options[i]), &sid);
611                 if (rc) {
612                         printk(KERN_WARNING "SELinux: security_context_to_sid"
613                                "(%s) failed for (dev %s, type %s) errno=%d\n",
614                                mount_options[i], sb->s_id, name, rc);
615                         goto out;
616                 }
617                 switch (flags[i]) {
618                 case FSCONTEXT_MNT:
619                         fscontext_sid = sid;
620
621                         if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
622                                         fscontext_sid))
623                                 goto out_double_mount;
624
625                         sbsec->flags |= FSCONTEXT_MNT;
626                         break;
627                 case CONTEXT_MNT:
628                         context_sid = sid;
629
630                         if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
631                                         context_sid))
632                                 goto out_double_mount;
633
634                         sbsec->flags |= CONTEXT_MNT;
635                         break;
636                 case ROOTCONTEXT_MNT:
637                         rootcontext_sid = sid;
638
639                         if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
640                                         rootcontext_sid))
641                                 goto out_double_mount;
642
643                         sbsec->flags |= ROOTCONTEXT_MNT;
644
645                         break;
646                 case DEFCONTEXT_MNT:
647                         defcontext_sid = sid;
648
649                         if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
650                                         defcontext_sid))
651                                 goto out_double_mount;
652
653                         sbsec->flags |= DEFCONTEXT_MNT;
654
655                         break;
656                 default:
657                         rc = -EINVAL;
658                         goto out;
659                 }
660         }
661
662         if (sbsec->initialized) {
663                 /* previously mounted with options, but not on this attempt? */
664                 if (sbsec->flags && !num_opts)
665                         goto out_double_mount;
666                 rc = 0;
667                 goto out;
668         }
669
670         if (strcmp(sb->s_type->name, "proc") == 0)
671                 sbsec->proc = 1;
672
673         /* Determine the labeling behavior to use for this filesystem type. */
674         rc = security_fs_use(sb->s_type->name, &sbsec->behavior, &sbsec->sid);
675         if (rc) {
676                 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
677                        __func__, sb->s_type->name, rc);
678                 goto out;
679         }
680
681         /* sets the context of the superblock for the fs being mounted. */
682         if (fscontext_sid) {
683
684                 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, tsec);
685                 if (rc)
686                         goto out;
687
688                 sbsec->sid = fscontext_sid;
689         }
690
691         /*
692          * Switch to using mount point labeling behavior.
693          * sets the label used on all file below the mountpoint, and will set
694          * the superblock context if not already set.
695          */
696         if (context_sid) {
697                 if (!fscontext_sid) {
698                         rc = may_context_mount_sb_relabel(context_sid, sbsec, tsec);
699                         if (rc)
700                                 goto out;
701                         sbsec->sid = context_sid;
702                 } else {
703                         rc = may_context_mount_inode_relabel(context_sid, sbsec, tsec);
704                         if (rc)
705                                 goto out;
706                 }
707                 if (!rootcontext_sid)
708                         rootcontext_sid = context_sid;
709
710                 sbsec->mntpoint_sid = context_sid;
711                 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
712         }
713
714         if (rootcontext_sid) {
715                 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, tsec);
716                 if (rc)
717                         goto out;
718
719                 root_isec->sid = rootcontext_sid;
720                 root_isec->initialized = 1;
721         }
722
723         if (defcontext_sid) {
724                 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
725                         rc = -EINVAL;
726                         printk(KERN_WARNING "SELinux: defcontext option is "
727                                "invalid for this filesystem type\n");
728                         goto out;
729                 }
730
731                 if (defcontext_sid != sbsec->def_sid) {
732                         rc = may_context_mount_inode_relabel(defcontext_sid,
733                                                              sbsec, tsec);
734                         if (rc)
735                                 goto out;
736                 }
737
738                 sbsec->def_sid = defcontext_sid;
739         }
740
741         rc = sb_finish_set_opts(sb);
742 out:
743         mutex_unlock(&sbsec->lock);
744         return rc;
745 out_double_mount:
746         rc = -EINVAL;
747         printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
748                "security settings for (dev %s, type %s)\n", sb->s_id, name);
749         goto out;
750 }
751
752 static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
753                                         struct super_block *newsb)
754 {
755         const struct superblock_security_struct *oldsbsec = oldsb->s_security;
756         struct superblock_security_struct *newsbsec = newsb->s_security;
757
758         int set_fscontext =     (oldsbsec->flags & FSCONTEXT_MNT);
759         int set_context =       (oldsbsec->flags & CONTEXT_MNT);
760         int set_rootcontext =   (oldsbsec->flags & ROOTCONTEXT_MNT);
761
762         /*
763          * if the parent was able to be mounted it clearly had no special lsm
764          * mount options.  thus we can safely put this sb on the list and deal
765          * with it later
766          */
767         if (!ss_initialized) {
768                 spin_lock(&sb_security_lock);
769                 if (list_empty(&newsbsec->list))
770                         list_add(&newsbsec->list, &superblock_security_head);
771                 spin_unlock(&sb_security_lock);
772                 return;
773         }
774
775         /* how can we clone if the old one wasn't set up?? */
776         BUG_ON(!oldsbsec->initialized);
777
778         /* if fs is reusing a sb, just let its options stand... */
779         if (newsbsec->initialized)
780                 return;
781
782         mutex_lock(&newsbsec->lock);
783
784         newsbsec->flags = oldsbsec->flags;
785
786         newsbsec->sid = oldsbsec->sid;
787         newsbsec->def_sid = oldsbsec->def_sid;
788         newsbsec->behavior = oldsbsec->behavior;
789
790         if (set_context) {
791                 u32 sid = oldsbsec->mntpoint_sid;
792
793                 if (!set_fscontext)
794                         newsbsec->sid = sid;
795                 if (!set_rootcontext) {
796                         struct inode *newinode = newsb->s_root->d_inode;
797                         struct inode_security_struct *newisec = newinode->i_security;
798                         newisec->sid = sid;
799                 }
800                 newsbsec->mntpoint_sid = sid;
801         }
802         if (set_rootcontext) {
803                 const struct inode *oldinode = oldsb->s_root->d_inode;
804                 const struct inode_security_struct *oldisec = oldinode->i_security;
805                 struct inode *newinode = newsb->s_root->d_inode;
806                 struct inode_security_struct *newisec = newinode->i_security;
807
808                 newisec->sid = oldisec->sid;
809         }
810
811         sb_finish_set_opts(newsb);
812         mutex_unlock(&newsbsec->lock);
813 }
814
815 static int selinux_parse_opts_str(char *options,
816                                   struct security_mnt_opts *opts)
817 {
818         char *p;
819         char *context = NULL, *defcontext = NULL;
820         char *fscontext = NULL, *rootcontext = NULL;
821         int rc, num_mnt_opts = 0;
822
823         opts->num_mnt_opts = 0;
824
825         /* Standard string-based options. */
826         while ((p = strsep(&options, "|")) != NULL) {
827                 int token;
828                 substring_t args[MAX_OPT_ARGS];
829
830                 if (!*p)
831                         continue;
832
833                 token = match_token(p, tokens, args);
834
835                 switch (token) {
836                 case Opt_context:
837                         if (context || defcontext) {
838                                 rc = -EINVAL;
839                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
840                                 goto out_err;
841                         }
842                         context = match_strdup(&args[0]);
843                         if (!context) {
844                                 rc = -ENOMEM;
845                                 goto out_err;
846                         }
847                         break;
848
849                 case Opt_fscontext:
850                         if (fscontext) {
851                                 rc = -EINVAL;
852                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
853                                 goto out_err;
854                         }
855                         fscontext = match_strdup(&args[0]);
856                         if (!fscontext) {
857                                 rc = -ENOMEM;
858                                 goto out_err;
859                         }
860                         break;
861
862                 case Opt_rootcontext:
863                         if (rootcontext) {
864                                 rc = -EINVAL;
865                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
866                                 goto out_err;
867                         }
868                         rootcontext = match_strdup(&args[0]);
869                         if (!rootcontext) {
870                                 rc = -ENOMEM;
871                                 goto out_err;
872                         }
873                         break;
874
875                 case Opt_defcontext:
876                         if (context || defcontext) {
877                                 rc = -EINVAL;
878                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
879                                 goto out_err;
880                         }
881                         defcontext = match_strdup(&args[0]);
882                         if (!defcontext) {
883                                 rc = -ENOMEM;
884                                 goto out_err;
885                         }
886                         break;
887
888                 default:
889                         rc = -EINVAL;
890                         printk(KERN_WARNING "SELinux:  unknown mount option\n");
891                         goto out_err;
892
893                 }
894         }
895
896         rc = -ENOMEM;
897         opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
898         if (!opts->mnt_opts)
899                 goto out_err;
900
901         opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
902         if (!opts->mnt_opts_flags) {
903                 kfree(opts->mnt_opts);
904                 goto out_err;
905         }
906
907         if (fscontext) {
908                 opts->mnt_opts[num_mnt_opts] = fscontext;
909                 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
910         }
911         if (context) {
912                 opts->mnt_opts[num_mnt_opts] = context;
913                 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
914         }
915         if (rootcontext) {
916                 opts->mnt_opts[num_mnt_opts] = rootcontext;
917                 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
918         }
919         if (defcontext) {
920                 opts->mnt_opts[num_mnt_opts] = defcontext;
921                 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
922         }
923
924         opts->num_mnt_opts = num_mnt_opts;
925         return 0;
926
927 out_err:
928         kfree(context);
929         kfree(defcontext);
930         kfree(fscontext);
931         kfree(rootcontext);
932         return rc;
933 }
934 /*
935  * string mount options parsing and call set the sbsec
936  */
937 static int superblock_doinit(struct super_block *sb, void *data)
938 {
939         int rc = 0;
940         char *options = data;
941         struct security_mnt_opts opts;
942
943         security_init_mnt_opts(&opts);
944
945         if (!data)
946                 goto out;
947
948         BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
949
950         rc = selinux_parse_opts_str(options, &opts);
951         if (rc)
952                 goto out_err;
953
954 out:
955         rc = selinux_set_mnt_opts(sb, &opts);
956
957 out_err:
958         security_free_mnt_opts(&opts);
959         return rc;
960 }
961
962 static void selinux_write_opts(struct seq_file *m,
963                                struct security_mnt_opts *opts)
964 {
965         int i;
966         char *prefix;
967
968         for (i = 0; i < opts->num_mnt_opts; i++) {
969                 char *has_comma = strchr(opts->mnt_opts[i], ',');
970
971                 switch (opts->mnt_opts_flags[i]) {
972                 case CONTEXT_MNT:
973                         prefix = CONTEXT_STR;
974                         break;
975                 case FSCONTEXT_MNT:
976                         prefix = FSCONTEXT_STR;
977                         break;
978                 case ROOTCONTEXT_MNT:
979                         prefix = ROOTCONTEXT_STR;
980                         break;
981                 case DEFCONTEXT_MNT:
982                         prefix = DEFCONTEXT_STR;
983                         break;
984                 default:
985                         BUG();
986                 };
987                 /* we need a comma before each option */
988                 seq_putc(m, ',');
989                 seq_puts(m, prefix);
990                 if (has_comma)
991                         seq_putc(m, '\"');
992                 seq_puts(m, opts->mnt_opts[i]);
993                 if (has_comma)
994                         seq_putc(m, '\"');
995         }
996 }
997
998 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
999 {
1000         struct security_mnt_opts opts;
1001         int rc;
1002
1003         rc = selinux_get_mnt_opts(sb, &opts);
1004         if (rc) {
1005                 /* before policy load we may get EINVAL, don't show anything */
1006                 if (rc == -EINVAL)
1007                         rc = 0;
1008                 return rc;
1009         }
1010
1011         selinux_write_opts(m, &opts);
1012
1013         security_free_mnt_opts(&opts);
1014
1015         return rc;
1016 }
1017
1018 static inline u16 inode_mode_to_security_class(umode_t mode)
1019 {
1020         switch (mode & S_IFMT) {
1021         case S_IFSOCK:
1022                 return SECCLASS_SOCK_FILE;
1023         case S_IFLNK:
1024                 return SECCLASS_LNK_FILE;
1025         case S_IFREG:
1026                 return SECCLASS_FILE;
1027         case S_IFBLK:
1028                 return SECCLASS_BLK_FILE;
1029         case S_IFDIR:
1030                 return SECCLASS_DIR;
1031         case S_IFCHR:
1032                 return SECCLASS_CHR_FILE;
1033         case S_IFIFO:
1034                 return SECCLASS_FIFO_FILE;
1035
1036         }
1037
1038         return SECCLASS_FILE;
1039 }
1040
1041 static inline int default_protocol_stream(int protocol)
1042 {
1043         return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1044 }
1045
1046 static inline int default_protocol_dgram(int protocol)
1047 {
1048         return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1049 }
1050
1051 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1052 {
1053         switch (family) {
1054         case PF_UNIX:
1055                 switch (type) {
1056                 case SOCK_STREAM:
1057                 case SOCK_SEQPACKET:
1058                         return SECCLASS_UNIX_STREAM_SOCKET;
1059                 case SOCK_DGRAM:
1060                         return SECCLASS_UNIX_DGRAM_SOCKET;
1061                 }
1062                 break;
1063         case PF_INET:
1064         case PF_INET6:
1065                 switch (type) {
1066                 case SOCK_STREAM:
1067                         if (default_protocol_stream(protocol))
1068                                 return SECCLASS_TCP_SOCKET;
1069                         else
1070                                 return SECCLASS_RAWIP_SOCKET;
1071                 case SOCK_DGRAM:
1072                         if (default_protocol_dgram(protocol))
1073                                 return SECCLASS_UDP_SOCKET;
1074                         else
1075                                 return SECCLASS_RAWIP_SOCKET;
1076                 case SOCK_DCCP:
1077                         return SECCLASS_DCCP_SOCKET;
1078                 default:
1079                         return SECCLASS_RAWIP_SOCKET;
1080                 }
1081                 break;
1082         case PF_NETLINK:
1083                 switch (protocol) {
1084                 case NETLINK_ROUTE:
1085                         return SECCLASS_NETLINK_ROUTE_SOCKET;
1086                 case NETLINK_FIREWALL:
1087                         return SECCLASS_NETLINK_FIREWALL_SOCKET;
1088                 case NETLINK_INET_DIAG:
1089                         return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1090                 case NETLINK_NFLOG:
1091                         return SECCLASS_NETLINK_NFLOG_SOCKET;
1092                 case NETLINK_XFRM:
1093                         return SECCLASS_NETLINK_XFRM_SOCKET;
1094                 case NETLINK_SELINUX:
1095                         return SECCLASS_NETLINK_SELINUX_SOCKET;
1096                 case NETLINK_AUDIT:
1097                         return SECCLASS_NETLINK_AUDIT_SOCKET;
1098                 case NETLINK_IP6_FW:
1099                         return SECCLASS_NETLINK_IP6FW_SOCKET;
1100                 case NETLINK_DNRTMSG:
1101                         return SECCLASS_NETLINK_DNRT_SOCKET;
1102                 case NETLINK_KOBJECT_UEVENT:
1103                         return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1104                 default:
1105                         return SECCLASS_NETLINK_SOCKET;
1106                 }
1107         case PF_PACKET:
1108                 return SECCLASS_PACKET_SOCKET;
1109         case PF_KEY:
1110                 return SECCLASS_KEY_SOCKET;
1111         case PF_APPLETALK:
1112                 return SECCLASS_APPLETALK_SOCKET;
1113         }
1114
1115         return SECCLASS_SOCKET;
1116 }
1117
1118 #ifdef CONFIG_PROC_FS
1119 static int selinux_proc_get_sid(struct proc_dir_entry *de,
1120                                 u16 tclass,
1121                                 u32 *sid)
1122 {
1123         int buflen, rc;
1124         char *buffer, *path, *end;
1125
1126         buffer = (char *)__get_free_page(GFP_KERNEL);
1127         if (!buffer)
1128                 return -ENOMEM;
1129
1130         buflen = PAGE_SIZE;
1131         end = buffer+buflen;
1132         *--end = '\0';
1133         buflen--;
1134         path = end-1;
1135         *path = '/';
1136         while (de && de != de->parent) {
1137                 buflen -= de->namelen + 1;
1138                 if (buflen < 0)
1139                         break;
1140                 end -= de->namelen;
1141                 memcpy(end, de->name, de->namelen);
1142                 *--end = '/';
1143                 path = end;
1144                 de = de->parent;
1145         }
1146         rc = security_genfs_sid("proc", path, tclass, sid);
1147         free_page((unsigned long)buffer);
1148         return rc;
1149 }
1150 #else
1151 static int selinux_proc_get_sid(struct proc_dir_entry *de,
1152                                 u16 tclass,
1153                                 u32 *sid)
1154 {
1155         return -EINVAL;
1156 }
1157 #endif
1158
1159 /* The inode's security attributes must be initialized before first use. */
1160 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1161 {
1162         struct superblock_security_struct *sbsec = NULL;
1163         struct inode_security_struct *isec = inode->i_security;
1164         u32 sid;
1165         struct dentry *dentry;
1166 #define INITCONTEXTLEN 255
1167         char *context = NULL;
1168         unsigned len = 0;
1169         int rc = 0;
1170
1171         if (isec->initialized)
1172                 goto out;
1173
1174         mutex_lock(&isec->lock);
1175         if (isec->initialized)
1176                 goto out_unlock;
1177
1178         sbsec = inode->i_sb->s_security;
1179         if (!sbsec->initialized) {
1180                 /* Defer initialization until selinux_complete_init,
1181                    after the initial policy is loaded and the security
1182                    server is ready to handle calls. */
1183                 spin_lock(&sbsec->isec_lock);
1184                 if (list_empty(&isec->list))
1185                         list_add(&isec->list, &sbsec->isec_head);
1186                 spin_unlock(&sbsec->isec_lock);
1187                 goto out_unlock;
1188         }
1189
1190         switch (sbsec->behavior) {
1191         case SECURITY_FS_USE_XATTR:
1192                 if (!inode->i_op->getxattr) {
1193                         isec->sid = sbsec->def_sid;
1194                         break;
1195                 }
1196
1197                 /* Need a dentry, since the xattr API requires one.
1198                    Life would be simpler if we could just pass the inode. */
1199                 if (opt_dentry) {
1200                         /* Called from d_instantiate or d_splice_alias. */
1201                         dentry = dget(opt_dentry);
1202                 } else {
1203                         /* Called from selinux_complete_init, try to find a dentry. */
1204                         dentry = d_find_alias(inode);
1205                 }
1206                 if (!dentry) {
1207                         printk(KERN_WARNING "SELinux: %s:  no dentry for dev=%s "
1208                                "ino=%ld\n", __func__, inode->i_sb->s_id,
1209                                inode->i_ino);
1210                         goto out_unlock;
1211                 }
1212
1213                 len = INITCONTEXTLEN;
1214                 context = kmalloc(len, GFP_NOFS);
1215                 if (!context) {
1216                         rc = -ENOMEM;
1217                         dput(dentry);
1218                         goto out_unlock;
1219                 }
1220                 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1221                                            context, len);
1222                 if (rc == -ERANGE) {
1223                         /* Need a larger buffer.  Query for the right size. */
1224                         rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1225                                                    NULL, 0);
1226                         if (rc < 0) {
1227                                 dput(dentry);
1228                                 goto out_unlock;
1229                         }
1230                         kfree(context);
1231                         len = rc;
1232                         context = kmalloc(len, GFP_NOFS);
1233                         if (!context) {
1234                                 rc = -ENOMEM;
1235                                 dput(dentry);
1236                                 goto out_unlock;
1237                         }
1238                         rc = inode->i_op->getxattr(dentry,
1239                                                    XATTR_NAME_SELINUX,
1240                                                    context, len);
1241                 }
1242                 dput(dentry);
1243                 if (rc < 0) {
1244                         if (rc != -ENODATA) {
1245                                 printk(KERN_WARNING "SELinux: %s:  getxattr returned "
1246                                        "%d for dev=%s ino=%ld\n", __func__,
1247                                        -rc, inode->i_sb->s_id, inode->i_ino);
1248                                 kfree(context);
1249                                 goto out_unlock;
1250                         }
1251                         /* Map ENODATA to the default file SID */
1252                         sid = sbsec->def_sid;
1253                         rc = 0;
1254                 } else {
1255                         rc = security_context_to_sid_default(context, rc, &sid,
1256                                                              sbsec->def_sid,
1257                                                              GFP_NOFS);
1258                         if (rc) {
1259                                 printk(KERN_WARNING "SELinux: %s:  context_to_sid(%s) "
1260                                        "returned %d for dev=%s ino=%ld\n",
1261                                        __func__, context, -rc,
1262                                        inode->i_sb->s_id, inode->i_ino);
1263                                 kfree(context);
1264                                 /* Leave with the unlabeled SID */
1265                                 rc = 0;
1266                                 break;
1267                         }
1268                 }
1269                 kfree(context);
1270                 isec->sid = sid;
1271                 break;
1272         case SECURITY_FS_USE_TASK:
1273                 isec->sid = isec->task_sid;
1274                 break;
1275         case SECURITY_FS_USE_TRANS:
1276                 /* Default to the fs SID. */
1277                 isec->sid = sbsec->sid;
1278
1279                 /* Try to obtain a transition SID. */
1280                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1281                 rc = security_transition_sid(isec->task_sid,
1282                                              sbsec->sid,
1283                                              isec->sclass,
1284                                              &sid);
1285                 if (rc)
1286                         goto out_unlock;
1287                 isec->sid = sid;
1288                 break;
1289         case SECURITY_FS_USE_MNTPOINT:
1290                 isec->sid = sbsec->mntpoint_sid;
1291                 break;
1292         default:
1293                 /* Default to the fs superblock SID. */
1294                 isec->sid = sbsec->sid;
1295
1296                 if (sbsec->proc && !S_ISLNK(inode->i_mode)) {
1297                         struct proc_inode *proci = PROC_I(inode);
1298                         if (proci->pde) {
1299                                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1300                                 rc = selinux_proc_get_sid(proci->pde,
1301                                                           isec->sclass,
1302                                                           &sid);
1303                                 if (rc)
1304                                         goto out_unlock;
1305                                 isec->sid = sid;
1306                         }
1307                 }
1308                 break;
1309         }
1310
1311         isec->initialized = 1;
1312
1313 out_unlock:
1314         mutex_unlock(&isec->lock);
1315 out:
1316         if (isec->sclass == SECCLASS_FILE)
1317                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1318         return rc;
1319 }
1320
1321 /* Convert a Linux signal to an access vector. */
1322 static inline u32 signal_to_av(int sig)
1323 {
1324         u32 perm = 0;
1325
1326         switch (sig) {
1327         case SIGCHLD:
1328                 /* Commonly granted from child to parent. */
1329                 perm = PROCESS__SIGCHLD;
1330                 break;
1331         case SIGKILL:
1332                 /* Cannot be caught or ignored */
1333                 perm = PROCESS__SIGKILL;
1334                 break;
1335         case SIGSTOP:
1336                 /* Cannot be caught or ignored */
1337                 perm = PROCESS__SIGSTOP;
1338                 break;
1339         default:
1340                 /* All other signals. */
1341                 perm = PROCESS__SIGNAL;
1342                 break;
1343         }
1344
1345         return perm;
1346 }
1347
1348 /* Check permission betweeen a pair of tasks, e.g. signal checks,
1349    fork check, ptrace check, etc. */
1350 static int task_has_perm(struct task_struct *tsk1,
1351                          struct task_struct *tsk2,
1352                          u32 perms)
1353 {
1354         struct task_security_struct *tsec1, *tsec2;
1355
1356         tsec1 = tsk1->cred->security;
1357         tsec2 = tsk2->cred->security;
1358         return avc_has_perm(tsec1->sid, tsec2->sid,
1359                             SECCLASS_PROCESS, perms, NULL);
1360 }
1361
1362 #if CAP_LAST_CAP > 63
1363 #error Fix SELinux to handle capabilities > 63.
1364 #endif
1365
1366 /* Check whether a task is allowed to use a capability. */
1367 static int task_has_capability(struct task_struct *tsk,
1368                                int cap, int audit)
1369 {
1370         struct task_security_struct *tsec;
1371         struct avc_audit_data ad;
1372         struct av_decision avd;
1373         u16 sclass;
1374         u32 av = CAP_TO_MASK(cap);
1375         int rc;
1376
1377         tsec = tsk->cred->security;
1378
1379         AVC_AUDIT_DATA_INIT(&ad, CAP);
1380         ad.tsk = tsk;
1381         ad.u.cap = cap;
1382
1383         switch (CAP_TO_INDEX(cap)) {
1384         case 0:
1385                 sclass = SECCLASS_CAPABILITY;
1386                 break;
1387         case 1:
1388                 sclass = SECCLASS_CAPABILITY2;
1389                 break;
1390         default:
1391                 printk(KERN_ERR
1392                        "SELinux:  out of range capability %d\n", cap);
1393                 BUG();
1394         }
1395
1396         rc = avc_has_perm_noaudit(tsec->sid, tsec->sid, sclass, av, 0, &avd);
1397         if (audit == SECURITY_CAP_AUDIT)
1398                 avc_audit(tsec->sid, tsec->sid, sclass, av, &avd, rc, &ad);
1399         return rc;
1400 }
1401
1402 /* Check whether a task is allowed to use a system operation. */
1403 static int task_has_system(struct task_struct *tsk,
1404                            u32 perms)
1405 {
1406         struct task_security_struct *tsec;
1407
1408         tsec = tsk->cred->security;
1409
1410         return avc_has_perm(tsec->sid, SECINITSID_KERNEL,
1411                             SECCLASS_SYSTEM, perms, NULL);
1412 }
1413
1414 /* Check whether a task has a particular permission to an inode.
1415    The 'adp' parameter is optional and allows other audit
1416    data to be passed (e.g. the dentry). */
1417 static int inode_has_perm(struct task_struct *tsk,
1418                           struct inode *inode,
1419                           u32 perms,
1420                           struct avc_audit_data *adp)
1421 {
1422         struct task_security_struct *tsec;
1423         struct inode_security_struct *isec;
1424         struct avc_audit_data ad;
1425
1426         if (unlikely(IS_PRIVATE(inode)))
1427                 return 0;
1428
1429         tsec = tsk->cred->security;
1430         isec = inode->i_security;
1431
1432         if (!adp) {
1433                 adp = &ad;
1434                 AVC_AUDIT_DATA_INIT(&ad, FS);
1435                 ad.u.fs.inode = inode;
1436         }
1437
1438         return avc_has_perm(tsec->sid, isec->sid, isec->sclass, perms, adp);
1439 }
1440
1441 /* Same as inode_has_perm, but pass explicit audit data containing
1442    the dentry to help the auditing code to more easily generate the
1443    pathname if needed. */
1444 static inline int dentry_has_perm(struct task_struct *tsk,
1445                                   struct vfsmount *mnt,
1446                                   struct dentry *dentry,
1447                                   u32 av)
1448 {
1449         struct inode *inode = dentry->d_inode;
1450         struct avc_audit_data ad;
1451         AVC_AUDIT_DATA_INIT(&ad, FS);
1452         ad.u.fs.path.mnt = mnt;
1453         ad.u.fs.path.dentry = dentry;
1454         return inode_has_perm(tsk, inode, av, &ad);
1455 }
1456
1457 /* Check whether a task can use an open file descriptor to
1458    access an inode in a given way.  Check access to the
1459    descriptor itself, and then use dentry_has_perm to
1460    check a particular permission to the file.
1461    Access to the descriptor is implicitly granted if it
1462    has the same SID as the process.  If av is zero, then
1463    access to the file is not checked, e.g. for cases
1464    where only the descriptor is affected like seek. */
1465 static int file_has_perm(struct task_struct *tsk,
1466                                 struct file *file,
1467                                 u32 av)
1468 {
1469         struct task_security_struct *tsec = tsk->cred->security;
1470         struct file_security_struct *fsec = file->f_security;
1471         struct inode *inode = file->f_path.dentry->d_inode;
1472         struct avc_audit_data ad;
1473         int rc;
1474
1475         AVC_AUDIT_DATA_INIT(&ad, FS);
1476         ad.u.fs.path = file->f_path;
1477
1478         if (tsec->sid != fsec->sid) {
1479                 rc = avc_has_perm(tsec->sid, fsec->sid,
1480                                   SECCLASS_FD,
1481                                   FD__USE,
1482                                   &ad);
1483                 if (rc)
1484                         return rc;
1485         }
1486
1487         /* av is zero if only checking access to the descriptor. */
1488         if (av)
1489                 return inode_has_perm(tsk, inode, av, &ad);
1490
1491         return 0;
1492 }
1493
1494 /* Check whether a task can create a file. */
1495 static int may_create(struct inode *dir,
1496                       struct dentry *dentry,
1497                       u16 tclass)
1498 {
1499         struct task_security_struct *tsec;
1500         struct inode_security_struct *dsec;
1501         struct superblock_security_struct *sbsec;
1502         u32 newsid;
1503         struct avc_audit_data ad;
1504         int rc;
1505
1506         tsec = current->cred->security;
1507         dsec = dir->i_security;
1508         sbsec = dir->i_sb->s_security;
1509
1510         AVC_AUDIT_DATA_INIT(&ad, FS);
1511         ad.u.fs.path.dentry = dentry;
1512
1513         rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR,
1514                           DIR__ADD_NAME | DIR__SEARCH,
1515                           &ad);
1516         if (rc)
1517                 return rc;
1518
1519         if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
1520                 newsid = tsec->create_sid;
1521         } else {
1522                 rc = security_transition_sid(tsec->sid, dsec->sid, tclass,
1523                                              &newsid);
1524                 if (rc)
1525                         return rc;
1526         }
1527
1528         rc = avc_has_perm(tsec->sid, newsid, tclass, FILE__CREATE, &ad);
1529         if (rc)
1530                 return rc;
1531
1532         return avc_has_perm(newsid, sbsec->sid,
1533                             SECCLASS_FILESYSTEM,
1534                             FILESYSTEM__ASSOCIATE, &ad);
1535 }
1536
1537 /* Check whether a task can create a key. */
1538 static int may_create_key(u32 ksid,
1539                           struct task_struct *ctx)
1540 {
1541         struct task_security_struct *tsec;
1542
1543         tsec = ctx->cred->security;
1544
1545         return avc_has_perm(tsec->sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1546 }
1547
1548 #define MAY_LINK        0
1549 #define MAY_UNLINK      1
1550 #define MAY_RMDIR       2
1551
1552 /* Check whether a task can link, unlink, or rmdir a file/directory. */
1553 static int may_link(struct inode *dir,
1554                     struct dentry *dentry,
1555                     int kind)
1556
1557 {
1558         struct task_security_struct *tsec;
1559         struct inode_security_struct *dsec, *isec;
1560         struct avc_audit_data ad;
1561         u32 av;
1562         int rc;
1563
1564         tsec = current->cred->security;
1565         dsec = dir->i_security;
1566         isec = dentry->d_inode->i_security;
1567
1568         AVC_AUDIT_DATA_INIT(&ad, FS);
1569         ad.u.fs.path.dentry = dentry;
1570
1571         av = DIR__SEARCH;
1572         av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1573         rc = avc_has_perm(tsec->sid, dsec->sid, SECCLASS_DIR, av, &ad);
1574         if (rc)
1575                 return rc;
1576
1577         switch (kind) {
1578         case MAY_LINK:
1579                 av = FILE__LINK;
1580                 break;
1581         case MAY_UNLINK:
1582                 av = FILE__UNLINK;
1583                 break;
1584         case MAY_RMDIR:
1585                 av = DIR__RMDIR;
1586                 break;
1587         default:
1588                 printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
1589                         __func__, kind);
1590                 return 0;
1591         }
1592
1593         rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass, av, &ad);
1594         return rc;
1595 }
1596
1597 static inline int may_rename(struct inode *old_dir,
1598                              struct dentry *old_dentry,
1599                              struct inode *new_dir,
1600                              struct dentry *new_dentry)
1601 {
1602         struct task_security_struct *tsec;
1603         struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1604         struct avc_audit_data ad;
1605         u32 av;
1606         int old_is_dir, new_is_dir;
1607         int rc;
1608
1609         tsec = current->cred->security;
1610         old_dsec = old_dir->i_security;
1611         old_isec = old_dentry->d_inode->i_security;
1612         old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1613         new_dsec = new_dir->i_security;
1614
1615         AVC_AUDIT_DATA_INIT(&ad, FS);
1616
1617         ad.u.fs.path.dentry = old_dentry;
1618         rc = avc_has_perm(tsec->sid, old_dsec->sid, SECCLASS_DIR,
1619                           DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1620         if (rc)
1621                 return rc;
1622         rc = avc_has_perm(tsec->sid, old_isec->sid,
1623                           old_isec->sclass, FILE__RENAME, &ad);
1624         if (rc)
1625                 return rc;
1626         if (old_is_dir && new_dir != old_dir) {
1627                 rc = avc_has_perm(tsec->sid, old_isec->sid,
1628                                   old_isec->sclass, DIR__REPARENT, &ad);
1629                 if (rc)
1630                         return rc;
1631         }
1632
1633         ad.u.fs.path.dentry = new_dentry;
1634         av = DIR__ADD_NAME | DIR__SEARCH;
1635         if (new_dentry->d_inode)
1636                 av |= DIR__REMOVE_NAME;
1637         rc = avc_has_perm(tsec->sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1638         if (rc)
1639                 return rc;
1640         if (new_dentry->d_inode) {
1641                 new_isec = new_dentry->d_inode->i_security;
1642                 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1643                 rc = avc_has_perm(tsec->sid, new_isec->sid,
1644                                   new_isec->sclass,
1645                                   (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1646                 if (rc)
1647                         return rc;
1648         }
1649
1650         return 0;
1651 }
1652
1653 /* Check whether a task can perform a filesystem operation. */
1654 static int superblock_has_perm(struct task_struct *tsk,
1655                                struct super_block *sb,
1656                                u32 perms,
1657                                struct avc_audit_data *ad)
1658 {
1659         struct task_security_struct *tsec;
1660         struct superblock_security_struct *sbsec;
1661
1662         tsec = tsk->cred->security;
1663         sbsec = sb->s_security;
1664         return avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
1665                             perms, ad);
1666 }
1667
1668 /* Convert a Linux mode and permission mask to an access vector. */
1669 static inline u32 file_mask_to_av(int mode, int mask)
1670 {
1671         u32 av = 0;
1672
1673         if ((mode & S_IFMT) != S_IFDIR) {
1674                 if (mask & MAY_EXEC)
1675                         av |= FILE__EXECUTE;
1676                 if (mask & MAY_READ)
1677                         av |= FILE__READ;
1678
1679                 if (mask & MAY_APPEND)
1680                         av |= FILE__APPEND;
1681                 else if (mask & MAY_WRITE)
1682                         av |= FILE__WRITE;
1683
1684         } else {
1685                 if (mask & MAY_EXEC)
1686                         av |= DIR__SEARCH;
1687                 if (mask & MAY_WRITE)
1688                         av |= DIR__WRITE;
1689                 if (mask & MAY_READ)
1690                         av |= DIR__READ;
1691         }
1692
1693         return av;
1694 }
1695
1696 /* Convert a Linux file to an access vector. */
1697 static inline u32 file_to_av(struct file *file)
1698 {
1699         u32 av = 0;
1700
1701         if (file->f_mode & FMODE_READ)
1702                 av |= FILE__READ;
1703         if (file->f_mode & FMODE_WRITE) {
1704                 if (file->f_flags & O_APPEND)
1705                         av |= FILE__APPEND;
1706                 else
1707                         av |= FILE__WRITE;
1708         }
1709         if (!av) {
1710                 /*
1711                  * Special file opened with flags 3 for ioctl-only use.
1712                  */
1713                 av = FILE__IOCTL;
1714         }
1715
1716         return av;
1717 }
1718
1719 /*
1720  * Convert a file to an access vector and include the correct open
1721  * open permission.
1722  */
1723 static inline u32 open_file_to_av(struct file *file)
1724 {
1725         u32 av = file_to_av(file);
1726
1727         if (selinux_policycap_openperm) {
1728                 mode_t mode = file->f_path.dentry->d_inode->i_mode;
1729                 /*
1730                  * lnk files and socks do not really have an 'open'
1731                  */
1732                 if (S_ISREG(mode))
1733                         av |= FILE__OPEN;
1734                 else if (S_ISCHR(mode))
1735                         av |= CHR_FILE__OPEN;
1736                 else if (S_ISBLK(mode))
1737                         av |= BLK_FILE__OPEN;
1738                 else if (S_ISFIFO(mode))
1739                         av |= FIFO_FILE__OPEN;
1740                 else if (S_ISDIR(mode))
1741                         av |= DIR__OPEN;
1742                 else
1743                         printk(KERN_ERR "SELinux: WARNING: inside %s with "
1744                                 "unknown mode:%o\n", __func__, mode);
1745         }
1746         return av;
1747 }
1748
1749 /* Hook functions begin here. */
1750
1751 static int selinux_ptrace_may_access(struct task_struct *child,
1752                                      unsigned int mode)
1753 {
1754         int rc;
1755
1756         rc = secondary_ops->ptrace_may_access(child, mode);
1757         if (rc)
1758                 return rc;
1759
1760         if (mode == PTRACE_MODE_READ) {
1761                 struct task_security_struct *tsec = current->cred->security;
1762                 struct task_security_struct *csec = child->cred->security;
1763                 return avc_has_perm(tsec->sid, csec->sid,
1764                                     SECCLASS_FILE, FILE__READ, NULL);
1765         }
1766
1767         return task_has_perm(current, child, PROCESS__PTRACE);
1768 }
1769
1770 static int selinux_ptrace_traceme(struct task_struct *parent)
1771 {
1772         int rc;
1773
1774         rc = secondary_ops->ptrace_traceme(parent);
1775         if (rc)
1776                 return rc;
1777
1778         return task_has_perm(parent, current, PROCESS__PTRACE);
1779 }
1780
1781 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1782                           kernel_cap_t *inheritable, kernel_cap_t *permitted)
1783 {
1784         int error;
1785
1786         error = task_has_perm(current, target, PROCESS__GETCAP);
1787         if (error)
1788                 return error;
1789
1790         return secondary_ops->capget(target, effective, inheritable, permitted);
1791 }
1792
1793 static int selinux_capset_check(const kernel_cap_t *effective,
1794                                 const kernel_cap_t *inheritable,
1795                                 const kernel_cap_t *permitted)
1796 {
1797         int error;
1798
1799         error = secondary_ops->capset_check(effective, inheritable, permitted);
1800         if (error)
1801                 return error;
1802
1803         return task_has_perm(current, current, PROCESS__SETCAP);
1804 }
1805
1806 static void selinux_capset_set(const kernel_cap_t *effective,
1807                                const kernel_cap_t *inheritable,
1808                                const kernel_cap_t *permitted)
1809 {
1810         secondary_ops->capset_set(effective, inheritable, permitted);
1811 }
1812
1813 static int selinux_capable(struct task_struct *tsk, int cap, int audit)
1814 {
1815         int rc;
1816
1817         rc = secondary_ops->capable(tsk, cap, audit);
1818         if (rc)
1819                 return rc;
1820
1821         return task_has_capability(tsk, cap, audit);
1822 }
1823
1824 static int selinux_sysctl_get_sid(ctl_table *table, u16 tclass, u32 *sid)
1825 {
1826         int buflen, rc;
1827         char *buffer, *path, *end;
1828
1829         rc = -ENOMEM;
1830         buffer = (char *)__get_free_page(GFP_KERNEL);
1831         if (!buffer)
1832                 goto out;
1833
1834         buflen = PAGE_SIZE;
1835         end = buffer+buflen;
1836         *--end = '\0';
1837         buflen--;
1838         path = end-1;
1839         *path = '/';
1840         while (table) {
1841                 const char *name = table->procname;
1842                 size_t namelen = strlen(name);
1843                 buflen -= namelen + 1;
1844                 if (buflen < 0)
1845                         goto out_free;
1846                 end -= namelen;
1847                 memcpy(end, name, namelen);
1848                 *--end = '/';
1849                 path = end;
1850                 table = table->parent;
1851         }
1852         buflen -= 4;
1853         if (buflen < 0)
1854                 goto out_free;
1855         end -= 4;
1856         memcpy(end, "/sys", 4);
1857         path = end;
1858         rc = security_genfs_sid("proc", path, tclass, sid);
1859 out_free:
1860         free_page((unsigned long)buffer);
1861 out:
1862         return rc;
1863 }
1864
1865 static int selinux_sysctl(ctl_table *table, int op)
1866 {
1867         int error = 0;
1868         u32 av;
1869         struct task_security_struct *tsec;
1870         u32 tsid;
1871         int rc;
1872
1873         rc = secondary_ops->sysctl(table, op);
1874         if (rc)
1875                 return rc;
1876
1877         tsec = current->cred->security;
1878
1879         rc = selinux_sysctl_get_sid(table, (op == 0001) ?
1880                                     SECCLASS_DIR : SECCLASS_FILE, &tsid);
1881         if (rc) {
1882                 /* Default to the well-defined sysctl SID. */
1883                 tsid = SECINITSID_SYSCTL;
1884         }
1885
1886         /* The op values are "defined" in sysctl.c, thereby creating
1887          * a bad coupling between this module and sysctl.c */
1888         if (op == 001) {
1889                 error = avc_has_perm(tsec->sid, tsid,
1890                                      SECCLASS_DIR, DIR__SEARCH, NULL);
1891         } else {
1892                 av = 0;
1893                 if (op & 004)
1894                         av |= FILE__READ;
1895                 if (op & 002)
1896                         av |= FILE__WRITE;
1897                 if (av)
1898                         error = avc_has_perm(tsec->sid, tsid,
1899                                              SECCLASS_FILE, av, NULL);
1900         }
1901
1902         return error;
1903 }
1904
1905 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1906 {
1907         int rc = 0;
1908
1909         if (!sb)
1910                 return 0;
1911
1912         switch (cmds) {
1913         case Q_SYNC:
1914         case Q_QUOTAON:
1915         case Q_QUOTAOFF:
1916         case Q_SETINFO:
1917         case Q_SETQUOTA:
1918                 rc = superblock_has_perm(current, sb, FILESYSTEM__QUOTAMOD,
1919                                          NULL);
1920                 break;
1921         case Q_GETFMT:
1922         case Q_GETINFO:
1923         case Q_GETQUOTA:
1924                 rc = superblock_has_perm(current, sb, FILESYSTEM__QUOTAGET,
1925                                          NULL);
1926                 break;
1927         default:
1928                 rc = 0;  /* let the kernel handle invalid cmds */
1929                 break;
1930         }
1931         return rc;
1932 }
1933
1934 static int selinux_quota_on(struct dentry *dentry)
1935 {
1936         return dentry_has_perm(current, NULL, dentry, FILE__QUOTAON);
1937 }
1938
1939 static int selinux_syslog(int type)
1940 {
1941         int rc;
1942
1943         rc = secondary_ops->syslog(type);
1944         if (rc)
1945                 return rc;
1946
1947         switch (type) {
1948         case 3:         /* Read last kernel messages */
1949         case 10:        /* Return size of the log buffer */
1950                 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1951                 break;
1952         case 6:         /* Disable logging to console */
1953         case 7:         /* Enable logging to console */
1954         case 8:         /* Set level of messages printed to console */
1955                 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1956                 break;
1957         case 0:         /* Close log */
1958         case 1:         /* Open log */
1959         case 2:         /* Read from log */
1960         case 4:         /* Read/clear last kernel messages */
1961         case 5:         /* Clear ring buffer */
1962         default:
1963                 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1964                 break;
1965         }
1966         return rc;
1967 }
1968
1969 /*
1970  * Check that a process has enough memory to allocate a new virtual
1971  * mapping. 0 means there is enough memory for the allocation to
1972  * succeed and -ENOMEM implies there is not.
1973  *
1974  * Note that secondary_ops->capable and task_has_perm_noaudit return 0
1975  * if the capability is granted, but __vm_enough_memory requires 1 if
1976  * the capability is granted.
1977  *
1978  * Do not audit the selinux permission check, as this is applied to all
1979  * processes that allocate mappings.
1980  */
1981 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
1982 {
1983         int rc, cap_sys_admin = 0;
1984
1985         rc = selinux_capable(current, CAP_SYS_ADMIN, SECURITY_CAP_NOAUDIT);
1986         if (rc == 0)
1987                 cap_sys_admin = 1;
1988
1989         return __vm_enough_memory(mm, pages, cap_sys_admin);
1990 }
1991
1992 /* binprm security operations */
1993
1994 static int selinux_bprm_alloc_security(struct linux_binprm *bprm)
1995 {
1996         struct bprm_security_struct *bsec;
1997
1998         bsec = kzalloc(sizeof(struct bprm_security_struct), GFP_KERNEL);
1999         if (!bsec)
2000                 return -ENOMEM;
2001
2002         bsec->sid = SECINITSID_UNLABELED;
2003         bsec->set = 0;
2004
2005         bprm->security = bsec;
2006         return 0;
2007 }
2008
2009 static int selinux_bprm_set_security(struct linux_binprm *bprm)
2010 {
2011         struct task_security_struct *tsec;
2012         struct inode *inode = bprm->file->f_path.dentry->d_inode;
2013         struct inode_security_struct *isec;
2014         struct bprm_security_struct *bsec;
2015         u32 newsid;
2016         struct avc_audit_data ad;
2017         int rc;
2018
2019         rc = secondary_ops->bprm_set_security(bprm);
2020         if (rc)
2021                 return rc;
2022
2023         bsec = bprm->security;
2024
2025         if (bsec->set)
2026                 return 0;
2027
2028         tsec = current->cred->security;
2029         isec = inode->i_security;
2030
2031         /* Default to the current task SID. */
2032         bsec->sid = tsec->sid;
2033
2034         /* Reset fs, key, and sock SIDs on execve. */
2035         tsec->create_sid = 0;
2036         tsec->keycreate_sid = 0;
2037         tsec->sockcreate_sid = 0;
2038
2039         if (tsec->exec_sid) {
2040                 newsid = tsec->exec_sid;
2041                 /* Reset exec SID on execve. */
2042                 tsec->exec_sid = 0;
2043         } else {
2044                 /* Check for a default transition on this program. */
2045                 rc = security_transition_sid(tsec->sid, isec->sid,
2046                                              SECCLASS_PROCESS, &newsid);
2047                 if (rc)
2048                         return rc;
2049         }
2050
2051         AVC_AUDIT_DATA_INIT(&ad, FS);
2052         ad.u.fs.path = bprm->file->f_path;
2053
2054         if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
2055                 newsid = tsec->sid;
2056
2057         if (tsec->sid == newsid) {
2058                 rc = avc_has_perm(tsec->sid, isec->sid,
2059                                   SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2060                 if (rc)
2061                         return rc;
2062         } else {
2063                 /* Check permissions for the transition. */
2064                 rc = avc_has_perm(tsec->sid, newsid,
2065                                   SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2066                 if (rc)
2067                         return rc;
2068
2069                 rc = avc_has_perm(newsid, isec->sid,
2070                                   SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2071                 if (rc)
2072                         return rc;
2073
2074                 /* Clear any possibly unsafe personality bits on exec: */
2075                 current->personality &= ~PER_CLEAR_ON_SETID;
2076
2077                 /* Set the security field to the new SID. */
2078                 bsec->sid = newsid;
2079         }
2080
2081         bsec->set = 1;
2082         return 0;
2083 }
2084
2085 static int selinux_bprm_check_security(struct linux_binprm *bprm)
2086 {
2087         return secondary_ops->bprm_check_security(bprm);
2088 }
2089
2090
2091 static int selinux_bprm_secureexec(struct linux_binprm *bprm)
2092 {
2093         struct task_security_struct *tsec = current->cred->security;
2094         int atsecure = 0;
2095
2096         if (tsec->osid != tsec->sid) {
2097                 /* Enable secure mode for SIDs transitions unless
2098                    the noatsecure permission is granted between
2099                    the two SIDs, i.e. ahp returns 0. */
2100                 atsecure = avc_has_perm(tsec->osid, tsec->sid,
2101                                          SECCLASS_PROCESS,
2102                                          PROCESS__NOATSECURE, NULL);
2103         }
2104
2105         return (atsecure || secondary_ops->bprm_secureexec(bprm));
2106 }
2107
2108 static void selinux_bprm_free_security(struct linux_binprm *bprm)
2109 {
2110         kfree(bprm->security);
2111         bprm->security = NULL;
2112 }
2113
2114 extern struct vfsmount *selinuxfs_mount;
2115 extern struct dentry *selinux_null;
2116
2117 /* Derived from fs/exec.c:flush_old_files. */
2118 static inline void flush_unauthorized_files(struct files_struct *files)
2119 {
2120         struct avc_audit_data ad;
2121         struct file *file, *devnull = NULL;
2122         struct tty_struct *tty;
2123         struct fdtable *fdt;
2124         long j = -1;
2125         int drop_tty = 0;
2126
2127         tty = get_current_tty();
2128         if (tty) {
2129                 file_list_lock();
2130                 if (!list_empty(&tty->tty_files)) {
2131                         struct inode *inode;
2132
2133                         /* Revalidate access to controlling tty.
2134                            Use inode_has_perm on the tty inode directly rather
2135                            than using file_has_perm, as this particular open
2136                            file may belong to another process and we are only
2137                            interested in the inode-based check here. */
2138                         file = list_first_entry(&tty->tty_files, struct file, f_u.fu_list);
2139                         inode = file->f_path.dentry->d_inode;
2140                         if (inode_has_perm(current, inode,
2141                                            FILE__READ | FILE__WRITE, NULL)) {
2142                                 drop_tty = 1;
2143                         }
2144                 }
2145                 file_list_unlock();
2146                 tty_kref_put(tty);
2147         }
2148         /* Reset controlling tty. */
2149         if (drop_tty)
2150                 no_tty();
2151
2152         /* Revalidate access to inherited open files. */
2153
2154         AVC_AUDIT_DATA_INIT(&ad, FS);
2155
2156         spin_lock(&files->file_lock);
2157         for (;;) {
2158                 unsigned long set, i;
2159                 int fd;
2160
2161                 j++;
2162                 i = j * __NFDBITS;
2163                 fdt = files_fdtable(files);
2164                 if (i >= fdt->max_fds)
2165                         break;
2166                 set = fdt->open_fds->fds_bits[j];
2167                 if (!set)
2168                         continue;
2169                 spin_unlock(&files->file_lock);
2170                 for ( ; set ; i++, set >>= 1) {
2171                         if (set & 1) {
2172                                 file = fget(i);
2173                                 if (!file)
2174                                         continue;
2175                                 if (file_has_perm(current,
2176                                                   file,
2177                                                   file_to_av(file))) {
2178                                         sys_close(i);
2179                                         fd = get_unused_fd();
2180                                         if (fd != i) {
2181                                                 if (fd >= 0)
2182                                                         put_unused_fd(fd);
2183                                                 fput(file);
2184                                                 continue;
2185                                         }
2186                                         if (devnull) {
2187                                                 get_file(devnull);
2188                                         } else {
2189                                                 devnull = dentry_open(dget(selinux_null), mntget(selinuxfs_mount), O_RDWR);
2190                                                 if (IS_ERR(devnull)) {
2191                                                         devnull = NULL;
2192                                                         put_unused_fd(fd);
2193                                                         fput(file);
2194                                                         continue;
2195                                                 }
2196                                         }
2197                                         fd_install(fd, devnull);
2198                                 }
2199                                 fput(file);
2200                         }
2201                 }
2202                 spin_lock(&files->file_lock);
2203
2204         }
2205         spin_unlock(&files->file_lock);
2206 }
2207
2208 static void selinux_bprm_apply_creds(struct linux_binprm *bprm, int unsafe)
2209 {
2210         struct task_security_struct *tsec;
2211         struct bprm_security_struct *bsec;
2212         u32 sid;
2213         int rc;
2214
2215         secondary_ops->bprm_apply_creds(bprm, unsafe);
2216
2217         tsec = current->cred->security;
2218
2219         bsec = bprm->security;
2220         sid = bsec->sid;
2221
2222         tsec->osid = tsec->sid;
2223         bsec->unsafe = 0;
2224         if (tsec->sid != sid) {
2225                 /* Check for shared state.  If not ok, leave SID
2226                    unchanged and kill. */
2227                 if (unsafe & LSM_UNSAFE_SHARE) {
2228                         rc = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
2229                                         PROCESS__SHARE, NULL);
2230                         if (rc) {
2231                                 bsec->unsafe = 1;
2232                                 return;
2233                         }
2234                 }
2235
2236                 /* Check for ptracing, and update the task SID if ok.
2237                    Otherwise, leave SID unchanged and kill. */
2238                 if (unsafe & (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2239                         struct task_struct *tracer;
2240                         struct task_security_struct *sec;
2241                         u32 ptsid = 0;
2242
2243                         rcu_read_lock();
2244                         tracer = tracehook_tracer_task(current);
2245                         if (likely(tracer != NULL)) {
2246                                 sec = tracer->cred->security;
2247                                 ptsid = sec->sid;
2248                         }
2249                         rcu_read_unlock();
2250
2251                         if (ptsid != 0) {
2252                                 rc = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
2253                                                   PROCESS__PTRACE, NULL);
2254                                 if (rc) {
2255                                         bsec->unsafe = 1;
2256                                         return;
2257                                 }
2258                         }
2259                 }
2260                 tsec->sid = sid;
2261         }
2262 }
2263
2264 /*
2265  * called after apply_creds without the task lock held
2266  */
2267 static void selinux_bprm_post_apply_creds(struct linux_binprm *bprm)
2268 {
2269         struct task_security_struct *tsec;
2270         struct rlimit *rlim, *initrlim;
2271         struct itimerval itimer;
2272         struct bprm_security_struct *bsec;
2273         struct sighand_struct *psig;
2274         int rc, i;
2275         unsigned long flags;
2276
2277         tsec = current->cred->security;
2278         bsec = bprm->security;
2279
2280         if (bsec->unsafe) {
2281                 force_sig_specific(SIGKILL, current);
2282                 return;
2283         }
2284         if (tsec->osid == tsec->sid)
2285                 return;
2286
2287         /* Close files for which the new task SID is not authorized. */
2288         flush_unauthorized_files(current->files);
2289
2290         /* Check whether the new SID can inherit signal state
2291            from the old SID.  If not, clear itimers to avoid
2292            subsequent signal generation and flush and unblock
2293            signals. This must occur _after_ the task SID has
2294           been updated so that any kill done after the flush
2295           will be checked against the new SID. */
2296         rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
2297                           PROCESS__SIGINH, NULL);
2298         if (rc) {
2299                 memset(&itimer, 0, sizeof itimer);
2300                 for (i = 0; i < 3; i++)
2301                         do_setitimer(i, &itimer, NULL);
2302                 flush_signals(current);
2303                 spin_lock_irq(&current->sighand->siglock);
2304                 flush_signal_handlers(current, 1);
2305                 sigemptyset(&current->blocked);
2306                 recalc_sigpending();
2307                 spin_unlock_irq(&current->sighand->siglock);
2308         }
2309
2310         /* Always clear parent death signal on SID transitions. */
2311         current->pdeath_signal = 0;
2312
2313         /* Check whether the new SID can inherit resource limits
2314            from the old SID.  If not, reset all soft limits to
2315            the lower of the current task's hard limit and the init
2316            task's soft limit.  Note that the setting of hard limits
2317            (even to lower them) can be controlled by the setrlimit
2318            check. The inclusion of the init task's soft limit into
2319            the computation is to avoid resetting soft limits higher
2320            than the default soft limit for cases where the default
2321            is lower than the hard limit, e.g. RLIMIT_CORE or
2322            RLIMIT_STACK.*/
2323         rc = avc_has_perm(tsec->osid, tsec->sid, SECCLASS_PROCESS,
2324                           PROCESS__RLIMITINH, NULL);
2325         if (rc) {
2326                 for (i = 0; i < RLIM_NLIMITS; i++) {
2327                         rlim = current->signal->rlim + i;
2328                         initrlim = init_task.signal->rlim+i;
2329                         rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2330                 }
2331                 update_rlimit_cpu(rlim->rlim_cur);
2332         }
2333
2334         /* Wake up the parent if it is waiting so that it can
2335            recheck wait permission to the new task SID. */
2336         read_lock_irq(&tasklist_lock);
2337         psig = current->parent->sighand;
2338         spin_lock_irqsave(&psig->siglock, flags);
2339         wake_up_interruptible(&current->parent->signal->wait_chldexit);
2340         spin_unlock_irqrestore(&psig->siglock, flags);
2341         read_unlock_irq(&tasklist_lock);
2342 }
2343
2344 /* superblock security operations */
2345
2346 static int selinux_sb_alloc_security(struct super_block *sb)
2347 {
2348         return superblock_alloc_security(sb);
2349 }
2350
2351 static void selinux_sb_free_security(struct super_block *sb)
2352 {
2353         superblock_free_security(sb);
2354 }
2355
2356 static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2357 {
2358         if (plen > olen)
2359                 return 0;
2360
2361         return !memcmp(prefix, option, plen);
2362 }
2363
2364 static inline int selinux_option(char *option, int len)
2365 {
2366         return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2367                 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2368                 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2369                 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len));
2370 }
2371
2372 static inline void take_option(char **to, char *from, int *first, int len)
2373 {
2374         if (!*first) {
2375                 **to = ',';
2376                 *to += 1;
2377         } else
2378                 *first = 0;
2379         memcpy(*to, from, len);
2380         *to += len;
2381 }
2382
2383 static inline void take_selinux_option(char **to, char *from, int *first,
2384                                        int len)
2385 {
2386         int current_size = 0;
2387
2388         if (!*first) {
2389                 **to = '|';
2390                 *to += 1;
2391         } else
2392                 *first = 0;
2393
2394         while (current_size < len) {
2395                 if (*from != '"') {
2396                         **to = *from;
2397                         *to += 1;
2398                 }
2399                 from += 1;
2400                 current_size += 1;
2401         }
2402 }
2403
2404 static int selinux_sb_copy_data(char *orig, char *copy)
2405 {
2406         int fnosec, fsec, rc = 0;
2407         char *in_save, *in_curr, *in_end;
2408         char *sec_curr, *nosec_save, *nosec;
2409         int open_quote = 0;
2410
2411         in_curr = orig;
2412         sec_curr = copy;
2413
2414         nosec = (char *)get_zeroed_page(GFP_KERNEL);
2415         if (!nosec) {
2416                 rc = -ENOMEM;
2417                 goto out;
2418         }
2419
2420         nosec_save = nosec;
2421         fnosec = fsec = 1;
2422         in_save = in_end = orig;
2423
2424         do {
2425                 if (*in_end == '"')
2426                         open_quote = !open_quote;
2427                 if ((*in_end == ',' && open_quote == 0) ||
2428                                 *in_end == '\0') {
2429                         int len = in_end - in_curr;
2430
2431                         if (selinux_option(in_curr, len))
2432                                 take_selinux_option(&sec_curr, in_curr, &fsec, len);
2433                         else
2434                                 take_option(&nosec, in_curr, &fnosec, len);
2435
2436                         in_curr = in_end + 1;
2437                 }
2438         } while (*in_end++);
2439
2440         strcpy(in_save, nosec_save);
2441         free_page((unsigned long)nosec_save);
2442 out:
2443         return rc;
2444 }
2445
2446 static int selinux_sb_kern_mount(struct super_block *sb, void *data)
2447 {
2448         struct avc_audit_data ad;
2449         int rc;
2450
2451         rc = superblock_doinit(sb, data);
2452         if (rc)
2453                 return rc;
2454
2455         AVC_AUDIT_DATA_INIT(&ad, FS);
2456         ad.u.fs.path.dentry = sb->s_root;
2457         return superblock_has_perm(current, sb, FILESYSTEM__MOUNT, &ad);
2458 }
2459
2460 static int selinux_sb_statfs(struct dentry *dentry)
2461 {
2462         struct avc_audit_data ad;
2463
2464         AVC_AUDIT_DATA_INIT(&ad, FS);
2465         ad.u.fs.path.dentry = dentry->d_sb->s_root;
2466         return superblock_has_perm(current, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2467 }
2468
2469 static int selinux_mount(char *dev_name,
2470                          struct path *path,
2471                          char *type,
2472                          unsigned long flags,
2473                          void *data)
2474 {
2475         int rc;
2476
2477         rc = secondary_ops->sb_mount(dev_name, path, type, flags, data);
2478         if (rc)
2479                 return rc;
2480
2481         if (flags & MS_REMOUNT)
2482                 return superblock_has_perm(current, path->mnt->mnt_sb,
2483                                            FILESYSTEM__REMOUNT, NULL);
2484         else
2485                 return dentry_has_perm(current, path->mnt, path->dentry,
2486                                        FILE__MOUNTON);
2487 }
2488
2489 static int selinux_umount(struct vfsmount *mnt, int flags)
2490 {
2491         int rc;
2492
2493         rc = secondary_ops->sb_umount(mnt, flags);
2494         if (rc)
2495                 return rc;
2496
2497         return superblock_has_perm(current, mnt->mnt_sb,
2498                                    FILESYSTEM__UNMOUNT, NULL);
2499 }
2500
2501 /* inode security operations */
2502
2503 static int selinux_inode_alloc_security(struct inode *inode)
2504 {
2505         return inode_alloc_security(inode);
2506 }
2507
2508 static void selinux_inode_free_security(struct inode *inode)
2509 {
2510         inode_free_security(inode);
2511 }
2512
2513 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2514                                        char **name, void **value,
2515                                        size_t *len)
2516 {
2517         struct task_security_struct *tsec;
2518         struct inode_security_struct *dsec;
2519         struct superblock_security_struct *sbsec;
2520         u32 newsid, clen;
2521         int rc;
2522         char *namep = NULL, *context;
2523
2524         tsec = current->cred->security;
2525         dsec = dir->i_security;
2526         sbsec = dir->i_sb->s_security;
2527
2528         if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) {
2529                 newsid = tsec->create_sid;
2530         } else {
2531                 rc = security_transition_sid(tsec->sid, dsec->sid,
2532                                              inode_mode_to_security_class(inode->i_mode),
2533                                              &newsid);
2534                 if (rc) {
2535                         printk(KERN_WARNING "%s:  "
2536                                "security_transition_sid failed, rc=%d (dev=%s "
2537                                "ino=%ld)\n",
2538                                __func__,
2539                                -rc, inode->i_sb->s_id, inode->i_ino);
2540                         return rc;
2541                 }
2542         }
2543
2544         /* Possibly defer initialization to selinux_complete_init. */
2545         if (sbsec->initialized) {
2546                 struct inode_security_struct *isec = inode->i_security;
2547                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2548                 isec->sid = newsid;
2549                 isec->initialized = 1;
2550         }
2551
2552         if (!ss_initialized || sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2553                 return -EOPNOTSUPP;
2554
2555         if (name) {
2556                 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
2557                 if (!namep)
2558                         return -ENOMEM;
2559                 *name = namep;
2560         }
2561
2562         if (value && len) {
2563                 rc = security_sid_to_context_force(newsid, &context, &clen);
2564                 if (rc) {
2565                         kfree(namep);
2566                         return rc;
2567                 }
2568                 *value = context;
2569                 *len = clen;
2570         }
2571
2572         return 0;
2573 }
2574
2575 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2576 {
2577         return may_create(dir, dentry, SECCLASS_FILE);
2578 }
2579
2580 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2581 {
2582         int rc;
2583
2584         rc = secondary_ops->inode_link(old_dentry, dir, new_dentry);
2585         if (rc)
2586                 return rc;
2587         return may_link(dir, old_dentry, MAY_LINK);
2588 }
2589
2590 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2591 {
2592         int rc;
2593
2594         rc = secondary_ops->inode_unlink(dir, dentry);
2595         if (rc)
2596                 return rc;
2597         return may_link(dir, dentry, MAY_UNLINK);
2598 }
2599
2600 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2601 {
2602         return may_create(dir, dentry, SECCLASS_LNK_FILE);
2603 }
2604
2605 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2606 {
2607         return may_create(dir, dentry, SECCLASS_DIR);
2608 }
2609
2610 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2611 {
2612         return may_link(dir, dentry, MAY_RMDIR);
2613 }
2614
2615 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2616 {
2617         int rc;
2618
2619         rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2620         if (rc)
2621                 return rc;
2622
2623         return may_create(dir, dentry, inode_mode_to_security_class(mode));
2624 }
2625
2626 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2627                                 struct inode *new_inode, struct dentry *new_dentry)
2628 {
2629         return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2630 }
2631
2632 static int selinux_inode_readlink(struct dentry *dentry)
2633 {
2634         return dentry_has_perm(current, NULL, dentry, FILE__READ);
2635 }
2636
2637 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2638 {
2639         int rc;
2640
2641         rc = secondary_ops->inode_follow_link(dentry, nameidata);
2642         if (rc)
2643                 return rc;
2644         return dentry_has_perm(current, NULL, dentry, FILE__READ);
2645 }
2646
2647 static int selinux_inode_permission(struct inode *inode, int mask)
2648 {
2649         int rc;
2650
2651         rc = secondary_ops->inode_permission(inode, mask);
2652         if (rc)
2653                 return rc;
2654
2655         if (!mask) {
2656                 /* No permission to check.  Existence test. */
2657                 return 0;
2658         }
2659
2660         return inode_has_perm(current, inode,
2661                               file_mask_to_av(inode->i_mode, mask), NULL);
2662 }
2663
2664 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2665 {
2666         int rc;
2667
2668         rc = secondary_ops->inode_setattr(dentry, iattr);
2669         if (rc)
2670                 return rc;
2671
2672         if (iattr->ia_valid & ATTR_FORCE)
2673                 return 0;
2674
2675         if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2676                                ATTR_ATIME_SET | ATTR_MTIME_SET))
2677                 return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2678
2679         return dentry_has_perm(current, NULL, dentry, FILE__WRITE);
2680 }
2681
2682 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2683 {
2684         return dentry_has_perm(current, mnt, dentry, FILE__GETATTR);
2685 }
2686
2687 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2688 {
2689         if (!strncmp(name, XATTR_SECURITY_PREFIX,
2690                      sizeof XATTR_SECURITY_PREFIX - 1)) {
2691                 if (!strcmp(name, XATTR_NAME_CAPS)) {
2692                         if (!capable(CAP_SETFCAP))
2693                                 return -EPERM;
2694                 } else if (!capable(CAP_SYS_ADMIN)) {
2695                         /* A different attribute in the security namespace.
2696                            Restrict to administrator. */
2697                         return -EPERM;
2698                 }
2699         }
2700
2701         /* Not an attribute we recognize, so just check the
2702            ordinary setattr permission. */
2703         return dentry_has_perm(current, NULL, dentry, FILE__SETATTR);
2704 }
2705
2706 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2707                                   const void *value, size_t size, int flags)
2708 {
2709         struct task_security_struct *tsec = current->cred->security;
2710         struct inode *inode = dentry->d_inode;
2711         struct inode_security_struct *isec = inode->i_security;
2712         struct superblock_security_struct *sbsec;
2713         struct avc_audit_data ad;
2714         u32 newsid;
2715         int rc = 0;
2716
2717         if (strcmp(name, XATTR_NAME_SELINUX))
2718                 return selinux_inode_setotherxattr(dentry, name);
2719
2720         sbsec = inode->i_sb->s_security;
2721         if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2722                 return -EOPNOTSUPP;
2723
2724         if (!is_owner_or_cap(inode))
2725                 return -EPERM;
2726
2727         AVC_AUDIT_DATA_INIT(&ad, FS);
2728         ad.u.fs.path.dentry = dentry;
2729
2730         rc = avc_has_perm(tsec->sid, isec->sid, isec->sclass,
2731                           FILE__RELABELFROM, &ad);
2732         if (rc)
2733                 return rc;
2734
2735         rc = security_context_to_sid(value, size, &newsid);
2736         if (rc == -EINVAL) {
2737                 if (!capable(CAP_MAC_ADMIN))
2738                         return rc;
2739                 rc = security_context_to_sid_force(value, size, &newsid);
2740         }
2741         if (rc)
2742                 return rc;
2743
2744         rc = avc_has_perm(tsec->sid, newsid, isec->sclass,
2745                           FILE__RELABELTO, &ad);
2746         if (rc)
2747                 return rc;
2748
2749         rc = security_validate_transition(isec->sid, newsid, tsec->sid,
2750                                           isec->sclass);
2751         if (rc)
2752                 return rc;
2753
2754         return avc_has_perm(newsid,
2755                             sbsec->sid,
2756                             SECCLASS_FILESYSTEM,
2757                             FILESYSTEM__ASSOCIATE,
2758                             &ad);
2759 }
2760
2761 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2762                                         const void *value, size_t size,
2763                                         int flags)
2764 {
2765         struct inode *inode = dentry->d_inode;
2766         struct inode_security_struct *isec = inode->i_security;
2767         u32 newsid;
2768         int rc;
2769
2770         if (strcmp(name, XATTR_NAME_SELINUX)) {
2771                 /* Not an attribute we recognize, so nothing to do. */
2772                 return;
2773         }
2774
2775         rc = security_context_to_sid_force(value, size, &newsid);
2776         if (rc) {
2777                 printk(KERN_ERR "SELinux:  unable to map context to SID"
2778                        "for (%s, %lu), rc=%d\n",
2779                        inode->i_sb->s_id, inode->i_ino, -rc);
2780                 return;
2781         }
2782
2783         isec->sid = newsid;
2784         return;
2785 }
2786
2787 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
2788 {
2789         return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2790 }
2791
2792 static int selinux_inode_listxattr(struct dentry *dentry)
2793 {
2794         return dentry_has_perm(current, NULL, dentry, FILE__GETATTR);
2795 }
2796
2797 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
2798 {
2799         if (strcmp(name, XATTR_NAME_SELINUX))
2800                 return selinux_inode_setotherxattr(dentry, name);
2801
2802         /* No one is allowed to remove a SELinux security label.
2803            You can change the label, but all data must be labeled. */
2804         return -EACCES;
2805 }
2806
2807 /*
2808  * Copy the inode security context value to the user.
2809  *
2810  * Permission check is handled by selinux_inode_getxattr hook.
2811  */
2812 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
2813 {
2814         u32 size;
2815         int error;
2816         char *context = NULL;
2817         struct inode_security_struct *isec = inode->i_security;
2818
2819         if (strcmp(name, XATTR_SELINUX_SUFFIX))
2820                 return -EOPNOTSUPP;
2821
2822         /*
2823          * If the caller has CAP_MAC_ADMIN, then get the raw context
2824          * value even if it is not defined by current policy; otherwise,
2825          * use the in-core value under current policy.
2826          * Use the non-auditing forms of the permission checks since
2827          * getxattr may be called by unprivileged processes commonly
2828          * and lack of permission just means that we fall back to the
2829          * in-core context value, not a denial.
2830          */
2831         error = selinux_capable(current, CAP_MAC_ADMIN, SECURITY_CAP_NOAUDIT);
2832         if (!error)
2833                 error = security_sid_to_context_force(isec->sid, &context,
2834                                                       &size);
2835         else
2836                 error = security_sid_to_context(isec->sid, &context, &size);
2837         if (error)
2838                 return error;
2839         error = size;
2840         if (alloc) {
2841                 *buffer = context;
2842                 goto out_nofree;
2843         }
2844         kfree(context);
2845 out_nofree:
2846         return error;
2847 }
2848
2849 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2850                                      const void *value, size_t size, int flags)
2851 {
2852         struct inode_security_struct *isec = inode->i_security;
2853         u32 newsid;
2854         int rc;
2855
2856         if (strcmp(name, XATTR_SELINUX_SUFFIX))
2857                 return -EOPNOTSUPP;
2858
2859         if (!value || !size)
2860                 return -EACCES;
2861
2862         rc = security_context_to_sid((void *)value, size, &newsid);
2863         if (rc)
2864                 return rc;
2865
2866         isec->sid = newsid;
2867         return 0;
2868 }
2869
2870 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2871 {
2872         const int len = sizeof(XATTR_NAME_SELINUX);
2873         if (buffer && len <= buffer_size)
2874                 memcpy(buffer, XATTR_NAME_SELINUX, len);
2875         return len;
2876 }
2877
2878 static int selinux_inode_need_killpriv(struct dentry *dentry)
2879 {
2880         return secondary_ops->inode_need_killpriv(dentry);
2881 }
2882
2883 static int selinux_inode_killpriv(struct dentry *dentry)
2884 {
2885         return secondary_ops->inode_killpriv(dentry);
2886 }
2887
2888 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2889 {
2890         struct inode_security_struct *isec = inode->i_security;
2891         *secid = isec->sid;
2892 }
2893
2894 /* file security operations */
2895
2896 static int selinux_revalidate_file_permission(struct file *file, int mask)
2897 {
2898         int rc;
2899         struct inode *inode = file->f_path.dentry->d_inode;
2900
2901         if (!mask) {
2902                 /* No permission to check.  Existence test. */
2903                 return 0;
2904         }
2905
2906         /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2907         if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2908                 mask |= MAY_APPEND;
2909
2910         rc = file_has_perm(current, file,
2911                            file_mask_to_av(inode->i_mode, mask));
2912         if (rc)
2913                 return rc;
2914
2915         return selinux_netlbl_inode_permission(inode, mask);
2916 }
2917
2918 static int selinux_file_permission(struct file *file, int mask)
2919 {
2920         struct inode *inode = file->f_path.dentry->d_inode;
2921         struct task_security_struct *tsec = current->cred->security;
2922         struct file_security_struct *fsec = file->f_security;
2923         struct inode_security_struct *isec = inode->i_security;
2924
2925         if (!mask) {
2926                 /* No permission to check.  Existence test. */
2927                 return 0;
2928         }
2929
2930         if (tsec->sid == fsec->sid && fsec->isid == isec->sid
2931             && fsec->pseqno == avc_policy_seqno())
2932                 return selinux_netlbl_inode_permission(inode, mask);
2933
2934         return selinux_revalidate_file_permission(file, mask);
2935 }
2936
2937 static int selinux_file_alloc_security(struct file *file)
2938 {
2939         return file_alloc_security(file);
2940 }
2941
2942 static void selinux_file_free_security(struct file *file)
2943 {
2944         file_free_security(file);
2945 }
2946
2947 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2948                               unsigned long arg)
2949 {
2950         u32 av = 0;
2951
2952         if (_IOC_DIR(cmd) & _IOC_WRITE)
2953                 av |= FILE__WRITE;
2954         if (_IOC_DIR(cmd) & _IOC_READ)
2955                 av |= FILE__READ;
2956         if (!av)
2957                 av = FILE__IOCTL;
2958
2959         return file_has_perm(current, file, av);
2960 }
2961
2962 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
2963 {
2964 #ifndef CONFIG_PPC32
2965         if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
2966                 /*
2967                  * We are making executable an anonymous mapping or a
2968                  * private file mapping that will also be writable.
2969                  * This has an additional check.
2970                  */
2971                 int rc = task_has_perm(current, current, PROCESS__EXECMEM);
2972                 if (rc)
2973                         return rc;
2974         }
2975 #endif
2976
2977         if (file) {
2978                 /* read access is always possible with a mapping */
2979                 u32 av = FILE__READ;
2980
2981                 /* write access only matters if the mapping is shared */
2982                 if (shared && (prot & PROT_WRITE))
2983                         av |= FILE__WRITE;
2984
2985                 if (prot & PROT_EXEC)
2986                         av |= FILE__EXECUTE;
2987
2988                 return file_has_perm(current, file, av);
2989         }
2990         return 0;
2991 }
2992
2993 static int selinux_file_mmap(struct file *file, unsigned long reqprot,
2994                              unsigned long prot, unsigned long flags,
2995                              unsigned long addr, unsigned long addr_only)
2996 {
2997         int rc = 0;
2998         u32 sid = ((struct task_security_struct *)
2999                    (current->cred->security))->sid;
3000
3001         if (addr < mmap_min_addr)
3002                 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3003                                   MEMPROTECT__MMAP_ZERO, NULL);
3004         if (rc || addr_only)
3005                 return rc;
3006
3007         if (selinux_checkreqprot)
3008                 prot = reqprot;
3009
3010         return file_map_prot_check(file, prot,
3011                                    (flags & MAP_TYPE) == MAP_SHARED);
3012 }
3013
3014 static int selinux_file_mprotect(struct vm_area_struct *vma,
3015                                  unsigned long reqprot,
3016                                  unsigned long prot)
3017 {
3018         int rc;
3019
3020         rc = secondary_ops->file_mprotect(vma, reqprot, prot);
3021         if (rc)
3022                 return rc;
3023
3024         if (selinux_checkreqprot)
3025                 prot = reqprot;
3026
3027 #ifndef CONFIG_PPC32
3028         if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3029                 rc = 0;
3030                 if (vma->vm_start >= vma->vm_mm->start_brk &&
3031                     vma->vm_end <= vma->vm_mm->brk) {
3032                         rc = task_has_perm(current, current,
3033                                            PROCESS__EXECHEAP);
3034                 } else if (!vma->vm_file &&
3035                            vma->vm_start <= vma->vm_mm->start_stack &&
3036                            vma->vm_end >= vma->vm_mm->start_stack) {
3037                         rc = task_has_perm(current, current, PROCESS__EXECSTACK);
3038                 } else if (vma->vm_file && vma->anon_vma) {
3039                         /*
3040                          * We are making executable a file mapping that has
3041                          * had some COW done. Since pages might have been
3042                          * written, check ability to execute the possibly
3043                          * modified content.  This typically should only
3044                          * occur for text relocations.
3045                          */
3046                         rc = file_has_perm(current, vma->vm_file,
3047                                            FILE__EXECMOD);
3048                 }
3049                 if (rc)
3050                         return rc;
3051         }
3052 #endif
3053
3054         return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3055 }
3056
3057 static int selinux_file_lock(struct file *file, unsigned int cmd)
3058 {
3059         return file_has_perm(current, file, FILE__LOCK);
3060 }
3061
3062 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3063                               unsigned long arg)
3064 {
3065         int err = 0;
3066
3067         switch (cmd) {
3068         case F_SETFL:
3069                 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3070                         err = -EINVAL;
3071                         break;
3072                 }
3073
3074                 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3075                         err = file_has_perm(current, file, FILE__WRITE);
3076                         break;
3077                 }
3078                 /* fall through */
3079         case F_SETOWN:
3080         case F_SETSIG:
3081         case F_GETFL:
3082         case F_GETOWN:
3083         case F_GETSIG:
3084                 /* Just check FD__USE permission */
3085                 err = file_has_perm(current, file, 0);
3086                 break;
3087         case F_GETLK:
3088         case F_SETLK:
3089         case F_SETLKW:
3090 #if BITS_PER_LONG == 32
3091         case F_GETLK64:
3092         case F_SETLK64:
3093         case F_SETLKW64:
3094 #endif
3095                 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3096                         err = -EINVAL;
3097                         break;
3098                 }
3099                 err = file_has_perm(current, file, FILE__LOCK);
3100                 break;
3101         }
3102
3103         return err;
3104 }
3105
3106 static int selinux_file_set_fowner(struct file *file)
3107 {
3108         struct task_security_struct *tsec;
3109         struct file_security_struct *fsec;
3110
3111         tsec = current->cred->security;
3112         fsec = file->f_security;
3113         fsec->fown_sid = tsec->sid;
3114
3115         return 0;
3116 }
3117
3118 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3119                                        struct fown_struct *fown, int signum)
3120 {
3121         struct file *file;
3122         u32 perm;
3123         struct task_security_struct *tsec;
3124         struct file_security_struct *fsec;
3125
3126         /* struct fown_struct is never outside the context of a struct file */
3127         file = container_of(fown, struct file, f_owner);
3128
3129         tsec = tsk->cred->security;
3130         fsec = file->f_security;
3131
3132         if (!signum)
3133                 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3134         else
3135                 perm = signal_to_av(signum);
3136
3137         return avc_has_perm(fsec->fown_sid, tsec->sid,
3138                             SECCLASS_PROCESS, perm, NULL);
3139 }
3140
3141 static int selinux_file_receive(struct file *file)
3142 {
3143         return file_has_perm(current, file, file_to_av(file));
3144 }
3145
3146 static int selinux_dentry_open(struct file *file)
3147 {
3148         struct file_security_struct *fsec;
3149         struct inode *inode;
3150         struct inode_security_struct *isec;
3151         inode = file->f_path.dentry->d_inode;
3152         fsec = file->f_security;
3153         isec = inode->i_security;
3154         /*
3155          * Save inode label and policy sequence number
3156          * at open-time so that selinux_file_permission
3157          * can determine whether revalidation is necessary.
3158          * Task label is already saved in the file security
3159          * struct as its SID.
3160          */
3161         fsec->isid = isec->sid;
3162         fsec->pseqno = avc_policy_seqno();
3163         /*
3164          * Since the inode label or policy seqno may have changed
3165          * between the selinux_inode_permission check and the saving
3166          * of state above, recheck that access is still permitted.
3167          * Otherwise, access might never be revalidated against the
3168          * new inode label or new policy.
3169          * This check is not redundant - do not remove.
3170          */
3171         return inode_has_perm(current, inode, open_file_to_av(file), NULL);
3172 }
3173
3174 /* task security operations */
3175
3176 static int selinux_task_create(unsigned long clone_flags)
3177 {
3178         int rc;
3179
3180         rc = secondary_ops->task_create(clone_flags);
3181         if (rc)
3182                 return rc;
3183
3184         return task_has_perm(current, current, PROCESS__FORK);
3185 }
3186
3187 static int selinux_task_alloc_security(struct task_struct *tsk)
3188 {
3189         struct task_security_struct *tsec1, *tsec2;
3190         int rc;
3191
3192         tsec1 = current->cred->security;
3193
3194         rc = task_alloc_security(tsk);
3195         if (rc)
3196                 return rc;
3197         tsec2 = tsk->cred->security;
3198
3199         tsec2->osid = tsec1->osid;
3200         tsec2->sid = tsec1->sid;
3201
3202         /* Retain the exec, fs, key, and sock SIDs across fork */
3203         tsec2->exec_sid = tsec1->exec_sid;
3204         tsec2->create_sid = tsec1->create_sid;
3205         tsec2->keycreate_sid = tsec1->keycreate_sid;
3206         tsec2->sockcreate_sid = tsec1->sockcreate_sid;
3207
3208         return 0;
3209 }
3210
3211 static void selinux_task_free_security(struct task_struct *tsk)
3212 {
3213         task_free_security(tsk);
3214 }
3215
3216 static int selinux_task_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
3217 {
3218         /* Since setuid only affects the current process, and
3219            since the SELinux controls are not based on the Linux
3220            identity attributes, SELinux does not need to control
3221            this operation.  However, SELinux does control the use
3222            of the CAP_SETUID and CAP_SETGID capabilities using the
3223            capable hook. */
3224         return 0;
3225 }
3226
3227 static int selinux_task_post_setuid(uid_t id0, uid_t id1, uid_t id2, int flags)
3228 {
3229         return secondary_ops->task_post_setuid(id0, id1, id2, flags);
3230 }
3231
3232 static int selinux_task_setgid(gid_t id0, gid_t id1, gid_t id2, int flags)
3233 {
3234         /* See the comment for setuid above. */
3235         return 0;
3236 }
3237
3238 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
3239 {
3240         return task_has_perm(current, p, PROCESS__SETPGID);
3241 }
3242
3243 static int selinux_task_getpgid(struct task_struct *p)
3244 {
3245         return task_has_perm(current, p, PROCESS__GETPGID);
3246 }
3247
3248 static int selinux_task_getsid(struct task_struct *p)
3249 {
3250         return task_has_perm(current, p, PROCESS__GETSESSION);
3251 }
3252
3253 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
3254 {
3255         struct task_security_struct *tsec = p->cred->security;
3256         *secid = tsec->sid;
3257 }
3258
3259 static int selinux_task_setgroups(struct group_info *group_info)
3260 {
3261         /* See the comment for setuid above. */
3262         return 0;
3263 }
3264
3265 static int selinux_task_setnice(struct task_struct *p, int nice)
3266 {
3267         int rc;
3268
3269         rc = secondary_ops->task_setnice(p, nice);
3270         if (rc)
3271                 return rc;
3272
3273         return task_has_perm(current, p, PROCESS__SETSCHED);
3274 }
3275
3276 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
3277 {
3278         int rc;
3279
3280         rc = secondary_ops->task_setioprio(p, ioprio);
3281         if (rc)
3282                 return rc;
3283
3284         return task_has_perm(current, p, PROCESS__SETSCHED);
3285 }
3286
3287 static int selinux_task_getioprio(struct task_struct *p)
3288 {
3289         return task_has_perm(current, p, PROCESS__GETSCHED);
3290 }
3291
3292 static int selinux_task_setrlimit(unsigned int resource, struct rlimit *new_rlim)
3293 {
3294         struct rlimit *old_rlim = current->signal->rlim + resource;
3295         int rc;
3296
3297         rc = secondary_ops->task_setrlimit(resource, new_rlim);
3298         if (rc)
3299                 return rc;
3300