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 /*
 160  * initialise the security for the init task
 161  */
 162 static void cred_init_security(void)
 163 {
 164         struct cred *cred = (struct cred *) current->real_cred;
 165         struct task_security_struct *tsec;
 166
 167         tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
 168         if (!tsec)
 169                 panic("SELinux:  Failed to initialize initial task.\n");
 170
 171         tsec->osid = tsec->sid = SECINITSID_KERNEL;
 172         cred->security = tsec;
 173 }
 174
 175 /*
 176  * get the security ID of a set of credentials
 177  */
 178 static inline u32 cred_sid(const struct cred *cred)
 179 {
 180         const struct task_security_struct *tsec;
 181
 182         tsec = cred->security;
 183         return tsec->sid;
 184 }
 185
 186 /*
 187  * get the objective security ID of a task
 188  */
 189 static inline u32 task_sid(const struct task_struct *task)
 190 {
 191         u32 sid;
 192
 193         rcu_read_lock();
 194         sid = cred_sid(__task_cred(task));
 195         rcu_read_unlock();
 196         return sid;
 197 }
 198
 199 /*
 200  * get the subjective security ID of the current task
 201  */
 202 static inline u32 current_sid(void)
 203 {
 204         const struct task_security_struct *tsec = current_cred()->security;
 205
 206         return tsec->sid;
 207 }
 208
 209 /* Allocate and free functions for each kind of security blob. */
 210
 211 static int inode_alloc_security(struct inode *inode)
 212 {
 213         struct inode_security_struct *isec;
 214         u32 sid = current_sid();
 215
 216         isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
 217         if (!isec)
 218                 return -ENOMEM;
 219
 220         mutex_init(&isec->lock);
 221         INIT_LIST_HEAD(&isec->list);
 222         isec->inode = inode;
 223         isec->sid = SECINITSID_UNLABELED;
 224         isec->sclass = SECCLASS_FILE;
 225         isec->task_sid = sid;
 226         inode->i_security = isec;
 227
 228         return 0;
 229 }
 230
 231 static void inode_free_security(struct inode *inode)
 232 {
 233         struct inode_security_struct *isec = inode->i_security;
 234         struct superblock_security_struct *sbsec = inode->i_sb->s_security;
 235
 236         spin_lock(&sbsec->isec_lock);
 237         if (!list_empty(&isec->list))
 238                 list_del_init(&isec->list);
 239         spin_unlock(&sbsec->isec_lock);
 240
 241         inode->i_security = NULL;
 242         kmem_cache_free(sel_inode_cache, isec);
 243 }
 244
 245 static int file_alloc_security(struct file *file)
 246 {
 247         struct file_security_struct *fsec;
 248         u32 sid = current_sid();
 249
 250         fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
 251         if (!fsec)
 252                 return -ENOMEM;
 253
 254         fsec->sid = sid;
 255         fsec->fown_sid = sid;
 256         file->f_security = fsec;
 257
 258         return 0;
 259 }
 260
 261 static void file_free_security(struct file *file)
 262 {
 263         struct file_security_struct *fsec = file->f_security;
 264         file->f_security = NULL;
 265         kfree(fsec);
 266 }
 267
 268 static int superblock_alloc_security(struct super_block *sb)
 269 {
 270         struct superblock_security_struct *sbsec;
 271
 272         sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
 273         if (!sbsec)
 274                 return -ENOMEM;
 275
 276         mutex_init(&sbsec->lock);
 277         INIT_LIST_HEAD(&sbsec->list);
 278         INIT_LIST_HEAD(&sbsec->isec_head);
 279         spin_lock_init(&sbsec->isec_lock);
 280         sbsec->sb = sb;
 281         sbsec->sid = SECINITSID_UNLABELED;
 282         sbsec->def_sid = SECINITSID_FILE;
 283         sbsec->mntpoint_sid = SECINITSID_UNLABELED;
 284         sb->s_security = sbsec;
 285
 286         return 0;
 287 }
 288
 289 static void superblock_free_security(struct super_block *sb)
 290 {
 291         struct superblock_security_struct *sbsec = sb->s_security;
 292
 293         spin_lock(&sb_security_lock);
 294         if (!list_empty(&sbsec->list))
 295                 list_del_init(&sbsec->list);
 296         spin_unlock(&sb_security_lock);
 297
 298         sb->s_security = NULL;
 299         kfree(sbsec);
 300 }
 301
 302 static int sk_alloc_security(struct sock *sk, int family, gfp_t priority)
 303 {
 304         struct sk_security_struct *ssec;
 305
 306         ssec = kzalloc(sizeof(*ssec), priority);
 307         if (!ssec)
 308                 return -ENOMEM;
 309
 310         ssec->peer_sid = SECINITSID_UNLABELED;
 311         ssec->sid = SECINITSID_UNLABELED;
 312         sk->sk_security = ssec;
 313
 314         selinux_netlbl_sk_security_reset(ssec, family);
 315
 316         return 0;
 317 }
 318
 319 static void sk_free_security(struct sock *sk)
 320 {
 321         struct sk_security_struct *ssec = sk->sk_security;
 322
 323         sk->sk_security = NULL;
 324         selinux_netlbl_sk_security_free(ssec);
 325         kfree(ssec);
 326 }
 327
 328 /* The security server must be initialized before
 329    any labeling or access decisions can be provided. */
 330 extern int ss_initialized;
 331
 332 /* The file system's label must be initialized prior to use. */
 333
 334 static char *labeling_behaviors[6] = {
 335         "uses xattr",
 336         "uses transition SIDs",
 337         "uses task SIDs",
 338         "uses genfs_contexts",
 339         "not configured for labeling",
 340         "uses mountpoint labeling",
 341 };
 342
 343 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
 344
 345 static inline int inode_doinit(struct inode *inode)
 346 {
 347         return inode_doinit_with_dentry(inode, NULL);
 348 }
 349
 350 enum {
 351         Opt_error = -1,
 352         Opt_context = 1,
 353         Opt_fscontext = 2,
 354         Opt_defcontext = 3,
 355         Opt_rootcontext = 4,
 356 };
 357
 358 static const match_table_t tokens = {
 359         {Opt_context, CONTEXT_STR "%s"},
 360         {Opt_fscontext, FSCONTEXT_STR "%s"},
 361         {Opt_defcontext, DEFCONTEXT_STR "%s"},
 362         {Opt_rootcontext, ROOTCONTEXT_STR "%s"},
 363         {Opt_error, NULL},
 364 };
 365
 366 #define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"
 367
 368 static int may_context_mount_sb_relabel(u32 sid,
 369                         struct superblock_security_struct *sbsec,
 370                         const struct cred *cred)
 371 {
 372         const struct task_security_struct *tsec = cred->security;
 373         int rc;
 374
 375         rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
 376                           FILESYSTEM__RELABELFROM, NULL);
 377         if (rc)
 378                 return rc;
 379
 380         rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
 381                           FILESYSTEM__RELABELTO, NULL);
 382         return rc;
 383 }
 384
 385 static int may_context_mount_inode_relabel(u32 sid,
 386                         struct superblock_security_struct *sbsec,
 387                         const struct cred *cred)
 388 {
 389         const struct task_security_struct *tsec = cred->security;
 390         int rc;
 391         rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
 392                           FILESYSTEM__RELABELFROM, NULL);
 393         if (rc)
 394                 return rc;
 395
 396         rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
 397                           FILESYSTEM__ASSOCIATE, NULL);
 398         return rc;
 399 }
 400
 401 static int sb_finish_set_opts(struct super_block *sb)
 402 {
 403         struct superblock_security_struct *sbsec = sb->s_security;
 404         struct dentry *root = sb->s_root;
 405         struct inode *root_inode = root->d_inode;
 406         int rc = 0;
 407
 408         if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
 409                 /* Make sure that the xattr handler exists and that no
 410                    error other than -ENODATA is returned by getxattr on
 411                    the root directory.  -ENODATA is ok, as this may be
 412                    the first boot of the SELinux kernel before we have
 413                    assigned xattr values to the filesystem. */
 414                 if (!root_inode->i_op->getxattr) {
 415                         printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
 416                                "xattr support\n", sb->s_id, sb->s_type->name);
 417                         rc = -EOPNOTSUPP;
 418                         goto out;
 419                 }
 420                 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
 421                 if (rc < 0 && rc != -ENODATA) {
 422                         if (rc == -EOPNOTSUPP)
 423                                 printk(KERN_WARNING "SELinux: (dev %s, type "
 424                                        "%s) has no security xattr handler\n",
 425                                        sb->s_id, sb->s_type->name);
 426                         else
 427                                 printk(KERN_WARNING "SELinux: (dev %s, type "
 428                                        "%s) getxattr errno %d\n", sb->s_id,
 429                                        sb->s_type->name, -rc);
 430                         goto out;
 431                 }
 432         }
 433
 434         sbsec->initialized = 1;
 435
 436         if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
 437                 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
 438                        sb->s_id, sb->s_type->name);
 439         else
 440                 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
 441                        sb->s_id, sb->s_type->name,
 442                        labeling_behaviors[sbsec->behavior-1]);
 443
 444         /* Initialize the root inode. */
 445         rc = inode_doinit_with_dentry(root_inode, root);
 446
 447         /* Initialize any other inodes associated with the superblock, e.g.
 448            inodes created prior to initial policy load or inodes created
 449            during get_sb by a pseudo filesystem that directly
 450            populates itself. */
 451         spin_lock(&sbsec->isec_lock);
 452 next_inode:
 453         if (!list_empty(&sbsec->isec_head)) {
 454                 struct inode_security_struct *isec =
 455                                 list_entry(sbsec->isec_head.next,
 456                                            struct inode_security_struct, list);
 457                 struct inode *inode = isec->inode;
 458                 spin_unlock(&sbsec->isec_lock);
 459                 inode = igrab(inode);
 460                 if (inode) {
 461                         if (!IS_PRIVATE(inode))
 462                                 inode_doinit(inode);
 463                         iput(inode);
 464                 }
 465                 spin_lock(&sbsec->isec_lock);
 466                 list_del_init(&isec->list);
 467                 goto next_inode;
 468         }
 469         spin_unlock(&sbsec->isec_lock);
 470 out:
 471         return rc;
 472 }
 473
 474 /*
 475  * This function should allow an FS to ask what it's mount security
 476  * options were so it can use those later for submounts, displaying
 477  * mount options, or whatever.
 478  */
 479 static int selinux_get_mnt_opts(const struct super_block *sb,
 480                                 struct security_mnt_opts *opts)
 481 {
 482         int rc = 0, i;
 483         struct superblock_security_struct *sbsec = sb->s_security;
 484         char *context = NULL;
 485         u32 len;
 486         char tmp;
 487
 488         security_init_mnt_opts(opts);
 489
 490         if (!sbsec->initialized)
 491                 return -EINVAL;
 492
 493         if (!ss_initialized)
 494                 return -EINVAL;
 495
 496         /*
 497          * if we ever use sbsec flags for anything other than tracking mount
 498          * settings this is going to need a mask
 499          */
 500         tmp = sbsec->flags;
 501         /* count the number of mount options for this sb */
 502         for (i = 0; i < 8; i++) {
 503                 if (tmp & 0x01)
 504                         opts->num_mnt_opts++;
 505                 tmp >>= 1;
 506         }
 507
 508         opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
 509         if (!opts->mnt_opts) {
 510                 rc = -ENOMEM;
 511                 goto out_free;
 512         }
 513
 514         opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
 515         if (!opts->mnt_opts_flags) {
 516                 rc = -ENOMEM;
 517                 goto out_free;
 518         }
 519
 520         i = 0;
 521         if (sbsec->flags & FSCONTEXT_MNT) {
 522                 rc = security_sid_to_context(sbsec->sid, &context, &len);
 523                 if (rc)
 524                         goto out_free;
 525                 opts->mnt_opts[i] = context;
 526                 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
 527         }
 528         if (sbsec->flags & CONTEXT_MNT) {
 529                 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
 530                 if (rc)
 531                         goto out_free;
 532                 opts->mnt_opts[i] = context;
 533                 opts->mnt_opts_flags[i++] = CONTEXT_MNT;
 534         }
 535         if (sbsec->flags & DEFCONTEXT_MNT) {
 536                 rc = security_sid_to_context(sbsec->def_sid, &context, &len);
 537                 if (rc)
 538                         goto out_free;
 539                 opts->mnt_opts[i] = context;
 540                 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
 541         }
 542         if (sbsec->flags & ROOTCONTEXT_MNT) {
 543                 struct inode *root = sbsec->sb->s_root->d_inode;
 544                 struct inode_security_struct *isec = root->i_security;
 545
 546                 rc = security_sid_to_context(isec->sid, &context, &len);
 547                 if (rc)
 548                         goto out_free;
 549                 opts->mnt_opts[i] = context;
 550                 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
 551         }
 552
 553         BUG_ON(i != opts->num_mnt_opts);
 554
 555         return 0;
 556
 557 out_free:
 558         security_free_mnt_opts(opts);
 559         return rc;
 560 }
 561
 562 static int bad_option(struct superblock_security_struct *sbsec, char flag,
 563                       u32 old_sid, u32 new_sid)
 564 {
 565         /* check if the old mount command had the same options */
 566         if (sbsec->initialized)
 567                 if (!(sbsec->flags & flag) ||
 568                     (old_sid != new_sid))
 569                         return 1;
 570
 571         /* check if we were passed the same options twice,
 572          * aka someone passed context=a,context=b
 573          */
 574         if (!sbsec->initialized)
 575                 if (sbsec->flags & flag)
 576                         return 1;
 577         return 0;
 578 }
 579
 580 /*
 581  * Allow filesystems with binary mount data to explicitly set mount point
 582  * labeling information.
 583  */
 584 static int selinux_set_mnt_opts(struct super_block *sb,
 585                                 struct security_mnt_opts *opts)
 586 {
 587         const struct cred *cred = current_cred();
 588         int rc = 0, i;
 589         struct superblock_security_struct *sbsec = sb->s_security;
 590         const char *name = sb->s_type->name;
 591         struct inode *inode = sbsec->sb->s_root->d_inode;
 592         struct inode_security_struct *root_isec = inode->i_security;
 593         u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
 594         u32 defcontext_sid = 0;
 595         char **mount_options = opts->mnt_opts;
 596         int *flags = opts->mnt_opts_flags;
 597         int num_opts = opts->num_mnt_opts;
 598
 599         mutex_lock(&sbsec->lock);
 600
 601         if (!ss_initialized) {
 602                 if (!num_opts) {
 603                         /* Defer initialization until selinux_complete_init,
 604                            after the initial policy is loaded and the security
 605                            server is ready to handle calls. */
 606                         spin_lock(&sb_security_lock);
 607                         if (list_empty(&sbsec->list))
 608                                 list_add(&sbsec->list, &superblock_security_head);
 609                         spin_unlock(&sb_security_lock);
 610                         goto out;
 611                 }
 612                 rc = -EINVAL;
 613                 printk(KERN_WARNING "SELinux: Unable to set superblock options "
 614                         "before the security server is initialized\n");
 615                 goto out;
 616         }
 617
 618         /*
 619          * Binary mount data FS will come through this function twice.  Once
 620          * from an explicit call and once from the generic calls from the vfs.
 621          * Since the generic VFS calls will not contain any security mount data
 622          * we need to skip the double mount verification.
 623          *
 624          * This does open a hole in which we will not notice if the first
 625          * mount using this sb set explict options and a second mount using
 626          * this sb does not set any security options.  (The first options
 627          * will be used for both mounts)
 628          */
 629         if (sbsec->initialized && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
 630             && (num_opts == 0))
 631                 goto out;
 632
 633         /*
 634          * parse the mount options, check if they are valid sids.
 635          * also check if someone is trying to mount the same sb more
 636          * than once with different security options.
 637          */
 638         for (i = 0; i < num_opts; i++) {
 639                 u32 sid;
 640                 rc = security_context_to_sid(mount_options[i],
 641                                              strlen(mount_options[i]), &sid);
 642                 if (rc) {
 643                         printk(KERN_WARNING "SELinux: security_context_to_sid"
 644                                "(%s) failed for (dev %s, type %s) errno=%d\n",
 645                                mount_options[i], sb->s_id, name, rc);
 646                         goto out;
 647                 }
 648                 switch (flags[i]) {
 649                 case FSCONTEXT_MNT:
 650                         fscontext_sid = sid;
 651
 652                         if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
 653                                         fscontext_sid))
 654                                 goto out_double_mount;
 655
 656                         sbsec->flags |= FSCONTEXT_MNT;
 657                         break;
 658                 case CONTEXT_MNT:
 659                         context_sid = sid;
 660
 661                         if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
 662                                         context_sid))
 663                                 goto out_double_mount;
 664
 665                         sbsec->flags |= CONTEXT_MNT;
 666                         break;
 667                 case ROOTCONTEXT_MNT:
 668                         rootcontext_sid = sid;
 669
 670                         if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
 671                                         rootcontext_sid))
 672                                 goto out_double_mount;
 673
 674                         sbsec->flags |= ROOTCONTEXT_MNT;
 675
 676                         break;
 677                 case DEFCONTEXT_MNT:
 678                         defcontext_sid = sid;
 679
 680                         if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
 681                                         defcontext_sid))
 682                                 goto out_double_mount;
 683
 684                         sbsec->flags |= DEFCONTEXT_MNT;
 685
 686                         break;
 687                 default:
 688                         rc = -EINVAL;
 689                         goto out;
 690                 }
 691         }
 692
 693         if (sbsec->initialized) {
 694                 /* previously mounted with options, but not on this attempt? */
 695                 if (sbsec->flags && !num_opts)
 696                         goto out_double_mount;
 697                 rc = 0;
 698                 goto out;
 699         }
 700
 701         if (strcmp(sb->s_type->name, "proc") == 0)
 702                 sbsec->proc = 1;
 703
 704         /* Determine the labeling behavior to use for this filesystem type. */
 705         rc = security_fs_use(sbsec->proc ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
 706         if (rc) {
 707                 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
 708                        __func__, sb->s_type->name, rc);
 709                 goto out;
 710         }
 711
 712         /* sets the context of the superblock for the fs being mounted. */
 713         if (fscontext_sid) {
 714                 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
 715                 if (rc)
 716                         goto out;
 717
 718                 sbsec->sid = fscontext_sid;
 719         }
 720
 721         /*
 722          * Switch to using mount point labeling behavior.
 723          * sets the label used on all file below the mountpoint, and will set
 724          * the superblock context if not already set.
 725          */
 726         if (context_sid) {
 727                 if (!fscontext_sid) {
 728                         rc = may_context_mount_sb_relabel(context_sid, sbsec,
 729                                                           cred);
 730                         if (rc)
 731                                 goto out;
 732                         sbsec->sid = context_sid;
 733                 } else {
 734                         rc = may_context_mount_inode_relabel(context_sid, sbsec,
 735                                                              cred);
 736                         if (rc)
 737                                 goto out;
 738                 }
 739                 if (!rootcontext_sid)
 740                         rootcontext_sid = context_sid;
 741
 742                 sbsec->mntpoint_sid = context_sid;
 743                 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
 744         }
 745
 746         if (rootcontext_sid) {
 747                 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
 748                                                      cred);
 749                 if (rc)
 750                         goto out;
 751
 752                 root_isec->sid = rootcontext_sid;
 753                 root_isec->initialized = 1;
 754         }
 755
 756         if (defcontext_sid) {
 757                 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
 758                         rc = -EINVAL;
 759                         printk(KERN_WARNING "SELinux: defcontext option is "
 760                                "invalid for this filesystem type\n");
 761                         goto out;
 762                 }
 763
 764                 if (defcontext_sid != sbsec->def_sid) {
 765                         rc = may_context_mount_inode_relabel(defcontext_sid,
 766                                                              sbsec, cred);
 767                         if (rc)
 768                                 goto out;
 769                 }
 770
 771                 sbsec->def_sid = defcontext_sid;
 772         }
 773
 774         rc = sb_finish_set_opts(sb);
 775 out:
 776         mutex_unlock(&sbsec->lock);
 777         return rc;
 778 out_double_mount:
 779         rc = -EINVAL;
 780         printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
 781                "security settings for (dev %s, type %s)\n", sb->s_id, name);
 782         goto out;
 783 }
 784
 785 static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
 786                                         struct super_block *newsb)
 787 {
 788         const struct superblock_security_struct *oldsbsec = oldsb->s_security;
 789         struct superblock_security_struct *newsbsec = newsb->s_security;
 790
 791         int set_fscontext =     (oldsbsec->flags & FSCONTEXT_MNT);
 792         int set_context =       (oldsbsec->flags & CONTEXT_MNT);
 793         int set_rootcontext =   (oldsbsec->flags & ROOTCONTEXT_MNT);
 794
 795         /*
 796          * if the parent was able to be mounted it clearly had no special lsm
 797          * mount options.  thus we can safely put this sb on the list and deal
 798          * with it later
 799          */
 800         if (!ss_initialized) {
 801                 spin_lock(&sb_security_lock);
 802                 if (list_empty(&newsbsec->list))
 803                         list_add(&newsbsec->list, &superblock_security_head);
 804                 spin_unlock(&sb_security_lock);
 805                 return;
 806         }
 807
 808         /* how can we clone if the old one wasn't set up?? */
 809         BUG_ON(!oldsbsec->initialized);
 810
 811         /* if fs is reusing a sb, just let its options stand... */
 812         if (newsbsec->initialized)
 813                 return;
 814
 815         mutex_lock(&newsbsec->lock);
 816
 817         newsbsec->flags = oldsbsec->flags;
 818
 819         newsbsec->sid = oldsbsec->sid;
 820         newsbsec->def_sid = oldsbsec->def_sid;
 821         newsbsec->behavior = oldsbsec->behavior;
 822
 823         if (set_context) {
 824                 u32 sid = oldsbsec->mntpoint_sid;
 825
 826                 if (!set_fscontext)
 827                         newsbsec->sid = sid;
 828                 if (!set_rootcontext) {
 829                         struct inode *newinode = newsb->s_root->d_inode;
 830                         struct inode_security_struct *newisec = newinode->i_security;
 831                         newisec->sid = sid;
 832                 }
 833                 newsbsec->mntpoint_sid = sid;
 834         }
 835         if (set_rootcontext) {
 836                 const struct inode *oldinode = oldsb->s_root->d_inode;
 837                 const struct inode_security_struct *oldisec = oldinode->i_security;
 838                 struct inode *newinode = newsb->s_root->d_inode;
 839                 struct inode_security_struct *newisec = newinode->i_security;
 840
 841                 newisec->sid = oldisec->sid;
 842         }
 843
 844         sb_finish_set_opts(newsb);
 845         mutex_unlock(&newsbsec->lock);
 846 }
 847
 848 static int selinux_parse_opts_str(char *options,
 849                                   struct security_mnt_opts *opts)
 850 {
 851         char *p;
 852         char *context = NULL, *defcontext = NULL;
 853         char *fscontext = NULL, *rootcontext = NULL;
 854         int rc, num_mnt_opts = 0;
 855
 856         opts->num_mnt_opts = 0;
 857
 858         /* Standard string-based options. */
 859         while ((p = strsep(&options, "|")) != NULL) {
 860                 int token;
 861                 substring_t args[MAX_OPT_ARGS];
 862
 863                 if (!*p)
 864                         continue;
 865
 866                 token = match_token(p, tokens, args);
 867
 868                 switch (token) {
 869                 case Opt_context:
 870                         if (context || defcontext) {
 871                                 rc = -EINVAL;
 872                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 873                                 goto out_err;
 874                         }
 875                         context = match_strdup(&args[0]);
 876                         if (!context) {
 877                                 rc = -ENOMEM;
 878                                 goto out_err;
 879                         }
 880                         break;
 881
 882                 case Opt_fscontext:
 883                         if (fscontext) {
 884                                 rc = -EINVAL;
 885                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 886                                 goto out_err;
 887                         }
 888                         fscontext = match_strdup(&args[0]);
 889                         if (!fscontext) {
 890                                 rc = -ENOMEM;
 891                                 goto out_err;
 892                         }
 893                         break;
 894
 895                 case Opt_rootcontext:
 896                         if (rootcontext) {
 897                                 rc = -EINVAL;
 898                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 899                                 goto out_err;
 900                         }
 901                         rootcontext = match_strdup(&args[0]);
 902                         if (!rootcontext) {
 903                                 rc = -ENOMEM;
 904                                 goto out_err;
 905                         }
 906                         break;
 907
 908                 case Opt_defcontext:
 909                         if (context || defcontext) {
 910                                 rc = -EINVAL;
 911                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 912                                 goto out_err;
 913                         }
 914                         defcontext = match_strdup(&args[0]);
 915                         if (!defcontext) {
 916                                 rc = -ENOMEM;
 917                                 goto out_err;
 918                         }
 919                         break;
 920
 921                 default:
 922                         rc = -EINVAL;
 923                         printk(KERN_WARNING "SELinux:  unknown mount option\n");
 924                         goto out_err;
 925
 926                 }
 927         }
 928
 929         rc = -ENOMEM;
 930         opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
 931         if (!opts->mnt_opts)
 932                 goto out_err;
 933
 934         opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
 935         if (!opts->mnt_opts_flags) {
 936                 kfree(opts->mnt_opts);
 937                 goto out_err;
 938         }
 939
 940         if (fscontext) {
 941                 opts->mnt_opts[num_mnt_opts] = fscontext;
 942                 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
 943         }
 944         if (context) {
 945                 opts->mnt_opts[num_mnt_opts] = context;
 946                 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
 947         }
 948         if (rootcontext) {
 949                 opts->mnt_opts[num_mnt_opts] = rootcontext;
 950                 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
 951         }
 952         if (defcontext) {
 953                 opts->mnt_opts[num_mnt_opts] = defcontext;
 954                 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
 955         }
 956
 957         opts->num_mnt_opts = num_mnt_opts;
 958         return 0;
 959
 960 out_err:
 961         kfree(context);
 962         kfree(defcontext);
 963         kfree(fscontext);
 964         kfree(rootcontext);
 965         return rc;
 966 }
 967 /*
 968  * string mount options parsing and call set the sbsec
 969  */
 970 static int superblock_doinit(struct super_block *sb, void *data)
 971 {
 972         int rc = 0;
 973         char *options = data;
 974         struct security_mnt_opts opts;
 975
 976         security_init_mnt_opts(&opts);
 977
 978         if (!data)
 979                 goto out;
 980
 981         BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
 982
 983         rc = selinux_parse_opts_str(options, &opts);
 984         if (rc)
 985                 goto out_err;
 986
 987 out:
 988         rc = selinux_set_mnt_opts(sb, &opts);
 989
 990 out_err:
 991         security_free_mnt_opts(&opts);
 992         return rc;
 993 }
 994
 995 static void selinux_write_opts(struct seq_file *m,
 996                                struct security_mnt_opts *opts)
 997 {
 998         int i;
 999         char *prefix;
1000
1001         for (i = 0; i < opts->num_mnt_opts; i++) {
1002                 char *has_comma = strchr(opts->mnt_opts[i], ',');
1003
1004                 switch (opts->mnt_opts_flags[i]) {
1005                 case CONTEXT_MNT:
1006                         prefix = CONTEXT_STR;
1007                         break;
1008                 case FSCONTEXT_MNT:
1009                         prefix = FSCONTEXT_STR;
1010                         break;
1011                 case ROOTCONTEXT_MNT:
1012                         prefix = ROOTCONTEXT_STR;
1013                         break;
1014                 case DEFCONTEXT_MNT:
1015                         prefix = DEFCONTEXT_STR;
1016                         break;
1017                 default:
1018                         BUG();
1019                 };
1020                 /* we need a comma before each option */
1021                 seq_putc(m, ',');
1022                 seq_puts(m, prefix);
1023                 if (has_comma)
1024                         seq_putc(m, '\"');
1025                 seq_puts(m, opts->mnt_opts[i]);
1026                 if (has_comma)
1027                         seq_putc(m, '\"');
1028         }
1029 }
1030
1031 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1032 {
1033         struct security_mnt_opts opts;
1034         int rc;
1035
1036         rc = selinux_get_mnt_opts(sb, &opts);
1037         if (rc) {
1038                 /* before policy load we may get EINVAL, don't show anything */
1039                 if (rc == -EINVAL)
1040                         rc = 0;
1041                 return rc;
1042         }
1043
1044         selinux_write_opts(m, &opts);
1045
1046         security_free_mnt_opts(&opts);
1047
1048         return rc;
1049 }
1050
1051 static inline u16 inode_mode_to_security_class(umode_t mode)
1052 {
1053         switch (mode & S_IFMT) {
1054         case S_IFSOCK:
1055                 return SECCLASS_SOCK_FILE;
1056         case S_IFLNK:
1057                 return SECCLASS_LNK_FILE;
1058         case S_IFREG:
1059                 return SECCLASS_FILE;
1060         case S_IFBLK:
1061                 return SECCLASS_BLK_FILE;
1062         case S_IFDIR:
1063                 return SECCLASS_DIR;
1064         case S_IFCHR:
1065                 return SECCLASS_CHR_FILE;
1066         case S_IFIFO:
1067                 return SECCLASS_FIFO_FILE;
1068
1069         }
1070
1071         return SECCLASS_FILE;
1072 }
1073
1074 static inline int default_protocol_stream(int protocol)
1075 {
1076         return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1077 }
1078
1079 static inline int default_protocol_dgram(int protocol)
1080 {
1081         return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1082 }
1083
1084 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1085 {
1086         switch (family) {
1087         case PF_UNIX:
1088                 switch (type) {
1089                 case SOCK_STREAM:
1090                 case SOCK_SEQPACKET:
1091                         return SECCLASS_UNIX_STREAM_SOCKET;
1092                 case SOCK_DGRAM:
1093                         return SECCLASS_UNIX_DGRAM_SOCKET;
1094                 }
1095                 break;
1096         case PF_INET:
1097         case PF_INET6:
1098                 switch (type) {
1099                 case SOCK_STREAM:
1100                         if (default_protocol_stream(protocol))
1101                                 return SECCLASS_TCP_SOCKET;
1102                         else
1103                                 return SECCLASS_RAWIP_SOCKET;
1104                 case SOCK_DGRAM:
1105                         if (default_protocol_dgram(protocol))
1106                                 return SECCLASS_UDP_SOCKET;
1107                         else
1108                                 return SECCLASS_RAWIP_SOCKET;
1109                 case SOCK_DCCP:
1110                         return SECCLASS_DCCP_SOCKET;
1111                 default:
1112                         return SECCLASS_RAWIP_SOCKET;
1113                 }
1114                 break;
1115         case PF_NETLINK:
1116                 switch (protocol) {
1117                 case NETLINK_ROUTE:
1118                         return SECCLASS_NETLINK_ROUTE_SOCKET;
1119                 case NETLINK_FIREWALL:
1120                         return SECCLASS_NETLINK_FIREWALL_SOCKET;
1121                 case NETLINK_INET_DIAG:
1122                         return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1123                 case NETLINK_NFLOG:
1124                         return SECCLASS_NETLINK_NFLOG_SOCKET;
1125                 case NETLINK_XFRM:
1126                         return SECCLASS_NETLINK_XFRM_SOCKET;
1127                 case NETLINK_SELINUX:
1128                         return SECCLASS_NETLINK_SELINUX_SOCKET;
1129                 case NETLINK_AUDIT:
1130                         return SECCLASS_NETLINK_AUDIT_SOCKET;
1131                 case NETLINK_IP6_FW:
1132                         return SECCLASS_NETLINK_IP6FW_SOCKET;
1133                 case NETLINK_DNRTMSG:
1134                         return SECCLASS_NETLINK_DNRT_SOCKET;
1135                 case NETLINK_KOBJECT_UEVENT:
1136                         return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1137                 default:
1138                         return SECCLASS_NETLINK_SOCKET;
1139                 }
1140         case PF_PACKET:
1141                 return SECCLASS_PACKET_SOCKET;
1142         case PF_KEY:
1143                 return SECCLASS_KEY_SOCKET;
1144         case PF_APPLETALK:
1145                 return SECCLASS_APPLETALK_SOCKET;
1146         }
1147
1148         return SECCLASS_SOCKET;
1149 }
1150
1151 #ifdef CONFIG_PROC_FS
1152 static int selinux_proc_get_sid(struct proc_dir_entry *de,
1153                                 u16 tclass,
1154                                 u32 *sid)
1155 {
1156         int buflen, rc;
1157         char *buffer, *path, *end;
1158
1159         buffer = (char *)__get_free_page(GFP_KERNEL);
1160         if (!buffer)
1161                 return -ENOMEM;
1162
1163         buflen = PAGE_SIZE;
1164         end = buffer+buflen;
1165         *--end = '\0';
1166         buflen--;
1167         path = end-1;
1168         *path = '/';
1169         while (de && de != de->parent) {
1170                 buflen -= de->namelen + 1;
1171                 if (buflen < 0)
1172                         break;
1173                 end -= de->namelen;
1174                 memcpy(end, de->name, de->namelen);
1175                 *--end = '/';
1176                 path = end;
1177                 de = de->parent;
1178         }
1179         rc = security_genfs_sid("proc", path, tclass, sid);
1180         free_page((unsigned long)buffer);
1181         return rc;
1182 }
1183 #else
1184 static int selinux_proc_get_sid(struct proc_dir_entry *de,
1185                                 u16 tclass,
1186                                 u32 *sid)
1187 {
1188         return -EINVAL;
1189 }
1190 #endif
1191
1192 /* The inode's security attributes must be initialized before first use. */
1193 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1194 {
1195         struct superblock_security_struct *sbsec = NULL;
1196         struct inode_security_struct *isec = inode->i_security;
1197         u32 sid;
1198         struct dentry *dentry;
1199 #define INITCONTEXTLEN 255
1200         char *context = NULL;
1201         unsigned len = 0;
1202         int rc = 0;
1203
1204         if (isec->initialized)
1205                 goto out;
1206
1207         mutex_lock(&isec->lock);
1208         if (isec->initialized)
1209                 goto out_unlock;
1210
1211         sbsec = inode->i_sb->s_security;
1212         if (!sbsec->initialized) {
1213                 /* Defer initialization until selinux_complete_init,
1214                    after the initial policy is loaded and the security
1215                    server is ready to handle calls. */
1216                 spin_lock(&sbsec->isec_lock);
1217                 if (list_empty(&isec->list))
1218                         list_add(&isec->list, &sbsec->isec_head);
1219                 spin_unlock(&sbsec->isec_lock);
1220                 goto out_unlock;
1221         }
1222
1223         switch (sbsec->behavior) {
1224         case SECURITY_FS_USE_XATTR:
1225                 if (!inode->i_op->getxattr) {
1226                         isec->sid = sbsec->def_sid;
1227                         break;
1228                 }
1229
1230                 /* Need a dentry, since the xattr API requires one.
1231                    Life would be simpler if we could just pass the inode. */
1232                 if (opt_dentry) {
1233                         /* Called from d_instantiate or d_splice_alias. */
1234                         dentry = dget(opt_dentry);
1235                 } else {
1236                         /* Called from selinux_complete_init, try to find a dentry. */
1237                         dentry = d_find_alias(inode);
1238                 }
1239                 if (!dentry) {
1240                         printk(KERN_WARNING "SELinux: %s:  no dentry for dev=%s "
1241                                "ino=%ld\n", __func__, inode->i_sb->s_id,
1242                                inode->i_ino);
1243                         goto out_unlock;
1244                 }
1245
1246                 len = INITCONTEXTLEN;
1247                 context = kmalloc(len, GFP_NOFS);
1248                 if (!context) {
1249                         rc = -ENOMEM;
1250                         dput(dentry);
1251                         goto out_unlock;
1252                 }
1253                 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1254                                            context, len);
1255                 if (rc == -ERANGE) {
1256                         /* Need a larger buffer.  Query for the right size. */
1257                         rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1258                                                    NULL, 0);
1259                         if (rc < 0) {
1260                                 dput(dentry);
1261                                 goto out_unlock;
1262                         }
1263                         kfree(context);
1264                         len = rc;
1265                         context = kmalloc(len, GFP_NOFS);
1266                         if (!context) {
1267                                 rc = -ENOMEM;
1268                                 dput(dentry);
1269                                 goto out_unlock;
1270                         }
1271                         rc = inode->i_op->getxattr(dentry,
1272                                                    XATTR_NAME_SELINUX,
1273                                                    context, len);
1274                 }
1275                 dput(dentry);
1276                 if (rc < 0) {
1277                         if (rc != -ENODATA) {
1278                                 printk(KERN_WARNING "SELinux: %s:  getxattr returned "
1279                                        "%d for dev=%s ino=%ld\n", __func__,
1280                                        -rc, inode->i_sb->s_id, inode->i_ino);
1281                                 kfree(context);
1282                                 goto out_unlock;
1283                         }
1284                         /* Map ENODATA to the default file SID */
1285                         sid = sbsec->def_sid;
1286                         rc = 0;
1287                 } else {
1288                         rc = security_context_to_sid_default(context, rc, &sid,
1289                                                              sbsec->def_sid,
1290                                                              GFP_NOFS);
1291                         if (rc) {
1292                                 printk(KERN_WARNING "SELinux: %s:  context_to_sid(%s) "
1293                                        "returned %d for dev=%s ino=%ld\n",
1294                                        __func__, context, -rc,
1295                                        inode->i_sb->s_id, inode->i_ino);
1296                                 kfree(context);
1297                                 /* Leave with the unlabeled SID */
1298                                 rc = 0;
1299                                 break;
1300                         }
1301                 }
1302                 kfree(context);
1303                 isec->sid = sid;
1304                 break;
1305         case SECURITY_FS_USE_TASK:
1306                 isec->sid = isec->task_sid;
1307                 break;
1308         case SECURITY_FS_USE_TRANS:
1309                 /* Default to the fs SID. */
1310                 isec->sid = sbsec->sid;
1311
1312                 /* Try to obtain a transition SID. */
1313                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1314                 rc = security_transition_sid(isec->task_sid,
1315                                              sbsec->sid,
1316                                              isec->sclass,
1317                                              &sid);
1318                 if (rc)
1319                         goto out_unlock;
1320                 isec->sid = sid;
1321                 break;
1322         case SECURITY_FS_USE_MNTPOINT:
1323                 isec->sid = sbsec->mntpoint_sid;
1324                 break;
1325         default:
1326                 /* Default to the fs superblock SID. */
1327                 isec->sid = sbsec->sid;
1328
1329                 if (sbsec->proc && !S_ISLNK(inode->i_mode)) {
1330                         struct proc_inode *proci = PROC_I(inode);
1331                         if (proci->pde) {
1332                                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1333                                 rc = selinux_proc_get_sid(proci->pde,
1334                                                           isec->sclass,
1335                                                           &sid);
1336                                 if (rc)
1337                                         goto out_unlock;
1338                                 isec->sid = sid;
1339                         }
1340                 }
1341                 break;
1342         }
1343
1344         isec->initialized = 1;
1345
1346 out_unlock:
1347         mutex_unlock(&isec->lock);
1348 out:
1349         if (isec->sclass == SECCLASS_FILE)
1350                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1351         return rc;
1352 }
1353
1354 /* Convert a Linux signal to an access vector. */
1355 static inline u32 signal_to_av(int sig)
1356 {
1357         u32 perm = 0;
1358
1359         switch (sig) {
1360         case SIGCHLD:
1361                 /* Commonly granted from child to parent. */
1362                 perm = PROCESS__SIGCHLD;
1363                 break;
1364         case SIGKILL:
1365                 /* Cannot be caught or ignored */
1366                 perm = PROCESS__SIGKILL;
1367                 break;
1368         case SIGSTOP:
1369                 /* Cannot be caught or ignored */
1370                 perm = PROCESS__SIGSTOP;
1371                 break;
1372         default:
1373                 /* All other signals. */
1374                 perm = PROCESS__SIGNAL;
1375                 break;
1376         }
1377
1378         return perm;
1379 }
1380
1381 /*
1382  * Check permission between a pair of credentials
1383  * fork check, ptrace check, etc.
1384  */
1385 static int cred_has_perm(const struct cred *actor,
1386                          const struct cred *target,
1387                          u32 perms)
1388 {
1389         u32 asid = cred_sid(actor), tsid = cred_sid(target);
1390
1391         return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
1392 }
1393
1394 /*
1395  * Check permission between a pair of tasks, e.g. signal checks,
1396  * fork check, ptrace check, etc.
1397  * tsk1 is the actor and tsk2 is the target
1398  * - this uses the default subjective creds of tsk1
1399  */
1400 static int task_has_perm(const struct task_struct *tsk1,
1401                          const struct task_struct *tsk2,
1402                          u32 perms)
1403 {
1404         const struct task_security_struct *__tsec1, *__tsec2;
1405         u32 sid1, sid2;
1406
1407         rcu_read_lock();
1408         __tsec1 = __task_cred(tsk1)->security;  sid1 = __tsec1->sid;
1409         __tsec2 = __task_cred(tsk2)->security;  sid2 = __tsec2->sid;
1410         rcu_read_unlock();
1411         return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
1412 }
1413
1414 /*
1415  * Check permission between current and another task, e.g. signal checks,
1416  * fork check, ptrace check, etc.
1417  * current is the actor and tsk2 is the target
1418  * - this uses current's subjective creds
1419  */
1420 static int current_has_perm(const struct task_struct *tsk,
1421                             u32 perms)
1422 {
1423         u32 sid, tsid;
1424
1425         sid = current_sid();
1426         tsid = task_sid(tsk);
1427         return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
1428 }
1429
1430 #if CAP_LAST_CAP > 63
1431 #error Fix SELinux to handle capabilities > 63.
1432 #endif
1433
1434 /* Check whether a task is allowed to use a capability. */
1435 static int task_has_capability(struct task_struct *tsk,
1436                                const struct cred *cred,
1437                                int cap, int audit)
1438 {
1439         struct avc_audit_data ad;
1440         struct av_decision avd;
1441         u16 sclass;
1442         u32 sid = cred_sid(cred);
1443         u32 av = CAP_TO_MASK(cap);
1444         int rc;
1445
1446         AVC_AUDIT_DATA_INIT(&ad, CAP);
1447         ad.tsk = tsk;
1448         ad.u.cap = cap;
1449
1450         switch (CAP_TO_INDEX(cap)) {
1451         case 0:
1452                 sclass = SECCLASS_CAPABILITY;
1453                 break;
1454         case 1:
1455                 sclass = SECCLASS_CAPABILITY2;
1456                 break;
1457         default:
1458                 printk(KERN_ERR
1459                        "SELinux:  out of range capability %d\n", cap);
1460                 BUG();
1461         }
1462
1463         rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1464         if (audit == SECURITY_CAP_AUDIT)
1465                 avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
1466         return rc;
1467 }
1468
1469 /* Check whether a task is allowed to use a system operation. */
1470 static int task_has_system(struct task_struct *tsk,
1471                            u32 perms)
1472 {
1473         u32 sid = task_sid(tsk);
1474
1475         return avc_has_perm(sid, SECINITSID_KERNEL,
1476                             SECCLASS_SYSTEM, perms, NULL);
1477 }
1478
1479 /* Check whether a task has a particular permission to an inode.
1480    The 'adp' parameter is optional and allows other audit
1481    data to be passed (e.g. the dentry). */
1482 static int inode_has_perm(const struct cred *cred,
1483                           struct inode *inode,
1484                           u32 perms,
1485                           struct avc_audit_data *adp)
1486 {
1487         struct inode_security_struct *isec;
1488         struct avc_audit_data ad;
1489         u32 sid;
1490
1491         if (unlikely(IS_PRIVATE(inode)))
1492                 return 0;
1493
1494         sid = cred_sid(cred);
1495         isec = inode->i_security;
1496
1497         if (!adp) {
1498                 adp = &ad;
1499                 AVC_AUDIT_DATA_INIT(&ad, FS);
1500                 ad.u.fs.inode = inode;
1501         }
1502
1503         return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
1504 }
1505
1506 /* Same as inode_has_perm, but pass explicit audit data containing
1507    the dentry to help the auditing code to more easily generate the
1508    pathname if needed. */
1509 static inline int dentry_has_perm(const struct cred *cred,
1510                                   struct vfsmount *mnt,
1511                                   struct dentry *dentry,
1512                                   u32 av)
1513 {
1514         struct inode *inode = dentry->d_inode;
1515         struct avc_audit_data ad;
1516
1517         AVC_AUDIT_DATA_INIT(&ad, FS);
1518         ad.u.fs.path.mnt = mnt;
1519         ad.u.fs.path.dentry = dentry;
1520         return inode_has_perm(cred, inode, av, &ad);
1521 }
1522
1523 /* Check whether a task can use an open file descriptor to
1524    access an inode in a given way.  Check access to the
1525    descriptor itself, and then use dentry_has_perm to
1526    check a particular permission to the file.
1527    Access to the descriptor is implicitly granted if it
1528    has the same SID as the process.  If av is zero, then
1529    access to the file is not checked, e.g. for cases
1530    where only the descriptor is affected like seek. */
1531 static int file_has_perm(const struct cred *cred,
1532                          struct file *file,
1533                          u32 av)
1534 {
1535         struct file_security_struct *fsec = file->f_security;
1536         struct inode *inode = file->f_path.dentry->d_inode;
1537         struct avc_audit_data ad;
1538         u32 sid = cred_sid(cred);
1539         int rc;
1540
1541         AVC_AUDIT_DATA_INIT(&ad, FS);
1542         ad.u.fs.path = file->f_path;
1543
1544         if (sid != fsec->sid) {
1545                 rc = avc_has_perm(sid, fsec->sid,
1546                                   SECCLASS_FD,
1547                                   FD__USE,
1548                                   &ad);
1549                 if (rc)
1550                         goto out;
1551         }
1552
1553         /* av is zero if only checking access to the descriptor. */
1554         rc = 0;
1555         if (av)
1556                 rc = inode_has_perm(cred, inode, av, &ad);
1557
1558 out:
1559         return rc;
1560 }
1561
1562 /* Check whether a task can create a file. */
1563 static int may_create(struct inode *dir,
1564                       struct dentry *dentry,
1565                       u16 tclass)
1566 {
1567         const struct cred *cred = current_cred();
1568         const struct task_security_struct *tsec = cred->security;
1569         struct inode_security_struct *dsec;
1570         struct superblock_security_struct *sbsec;
1571         u32 sid, newsid;
1572         struct avc_audit_data ad;
1573         int rc;
1574
1575         dsec = dir->i_security;
1576         sbsec = dir->i_sb->s_security;
1577
1578         sid = tsec->sid;
1579         newsid = tsec->create_sid;
1580
1581         AVC_AUDIT_DATA_INIT(&ad, FS);
1582         ad.u.fs.path.dentry = dentry;
1583
1584         rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1585                           DIR__ADD_NAME | DIR__SEARCH,
1586                           &ad);
1587         if (rc)
1588                 return rc;
1589
1590         if (!newsid || sbsec->behavior == SECURITY_FS_USE_MNTPOINT) {
1591                 rc = security_transition_sid(sid, dsec->sid, tclass, &newsid);
1592                 if (rc)
1593                         return rc;
1594         }
1595
1596         rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1597         if (rc)
1598                 return rc;
1599
1600         return avc_has_perm(newsid, sbsec->sid,
1601                             SECCLASS_FILESYSTEM,
1602                             FILESYSTEM__ASSOCIATE, &ad);
1603 }
1604
1605 /* Check whether a task can create a key. */
1606 static int may_create_key(u32 ksid,
1607                           struct task_struct *ctx)
1608 {
1609         u32 sid = task_sid(ctx);
1610
1611         return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1612 }
1613
1614 #define MAY_LINK        0
1615 #define MAY_UNLINK      1
1616 #define MAY_RMDIR       2
1617
1618 /* Check whether a task can link, unlink, or rmdir a file/directory. */
1619 static int may_link(struct inode *dir,
1620                     struct dentry *dentry,
1621                     int kind)
1622
1623 {
1624         struct inode_security_struct *dsec, *isec;
1625         struct avc_audit_data ad;
1626         u32 sid = current_sid();
1627         u32 av;
1628         int rc;
1629
1630         dsec = dir->i_security;
1631         isec = dentry->d_inode->i_security;
1632
1633         AVC_AUDIT_DATA_INIT(&ad, FS);
1634         ad.u.fs.path.dentry = dentry;
1635
1636         av = DIR__SEARCH;
1637         av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1638         rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1639         if (rc)
1640                 return rc;
1641
1642         switch (kind) {
1643         case MAY_LINK:
1644                 av = FILE__LINK;
1645                 break;
1646         case MAY_UNLINK:
1647                 av = FILE__UNLINK;
1648                 break;
1649         case MAY_RMDIR:
1650                 av = DIR__RMDIR;
1651                 break;
1652         default:
1653                 printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
1654                         __func__, kind);
1655                 return 0;
1656         }
1657
1658         rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1659         return rc;
1660 }
1661
1662 static inline int may_rename(struct inode *old_dir,
1663                              struct dentry *old_dentry,
1664                              struct inode *new_dir,
1665                              struct dentry *new_dentry)
1666 {
1667         struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1668         struct avc_audit_data ad;
1669         u32 sid = current_sid();
1670         u32 av;
1671         int old_is_dir, new_is_dir;
1672         int rc;
1673
1674         old_dsec = old_dir->i_security;
1675         old_isec = old_dentry->d_inode->i_security;
1676         old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1677         new_dsec = new_dir->i_security;
1678
1679         AVC_AUDIT_DATA_INIT(&ad, FS);
1680
1681         ad.u.fs.path.dentry = old_dentry;
1682         rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1683                           DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1684         if (rc)
1685                 return rc;
1686         rc = avc_has_perm(sid, old_isec->sid,
1687                           old_isec->sclass, FILE__RENAME, &ad);
1688         if (rc)
1689                 return rc;
1690         if (old_is_dir && new_dir != old_dir) {
1691                 rc = avc_has_perm(sid, old_isec->sid,
1692                                   old_isec->sclass, DIR__REPARENT, &ad);
1693                 if (rc)
1694                         return rc;
1695         }
1696
1697         ad.u.fs.path.dentry = new_dentry;
1698         av = DIR__ADD_NAME | DIR__SEARCH;
1699         if (new_dentry->d_inode)
1700                 av |= DIR__REMOVE_NAME;
1701         rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1702         if (rc)
1703                 return rc;
1704         if (new_dentry->d_inode) {
1705                 new_isec = new_dentry->d_inode->i_security;
1706                 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1707                 rc = avc_has_perm(sid, new_isec->sid,
1708                                   new_isec->sclass,
1709                                   (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1710                 if (rc)
1711                         return rc;
1712         }
1713
1714         return 0;
1715 }
1716
1717 /* Check whether a task can perform a filesystem operation. */
1718 static int superblock_has_perm(const struct cred *cred,
1719                                struct super_block *sb,
1720                                u32 perms,
1721                                struct avc_audit_data *ad)
1722 {
1723         struct superblock_security_struct *sbsec;
1724         u32 sid = cred_sid(cred);
1725
1726         sbsec = sb->s_security;
1727         return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1728 }
1729
1730 /* Convert a Linux mode and permission mask to an access vector. */
1731 static inline u32 file_mask_to_av(int mode, int mask)
1732 {
1733         u32 av = 0;
1734
1735         if ((mode & S_IFMT) != S_IFDIR) {
1736                 if (mask & MAY_EXEC)
1737                         av |= FILE__EXECUTE;
1738                 if (mask & MAY_READ)
1739                         av |= FILE__READ;
1740
1741                 if (mask & MAY_APPEND)
1742                         av |= FILE__APPEND;
1743                 else if (mask & MAY_WRITE)
1744                         av |= FILE__WRITE;
1745
1746         } else {
1747                 if (mask & MAY_EXEC)
1748                         av |= DIR__SEARCH;
1749                 if (mask & MAY_WRITE)
1750                         av |= DIR__WRITE;
1751                 if (mask & MAY_READ)
1752                         av |= DIR__READ;
1753         }
1754
1755         return av;
1756 }
1757
1758 /* Convert a Linux file to an access vector. */
1759 static inline u32 file_to_av(struct file *file)
1760 {
1761         u32 av = 0;
1762
1763         if (file->f_mode & FMODE_READ)
1764                 av |= FILE__READ;
1765         if (file->f_mode & FMODE_WRITE) {
1766                 if (file->f_flags & O_APPEND)
1767                         av |= FILE__APPEND;
1768                 else
1769                         av |= FILE__WRITE;
1770         }
1771         if (!av) {
1772                 /*
1773                  * Special file opened with flags 3 for ioctl-only use.
1774                  */
1775                 av = FILE__IOCTL;
1776         }
1777
1778         return av;
1779 }
1780
1781 /*
1782  * Convert a file to an access vector and include the correct open
1783  * open permission.
1784  */
1785 static inline u32 open_file_to_av(struct file *file)
1786 {
1787         u32 av = file_to_av(file);
1788
1789         if (selinux_policycap_openperm) {
1790                 mode_t mode = file->f_path.dentry->d_inode->i_mode;
1791                 /*
1792                  * lnk files and socks do not really have an 'open'
1793                  */
1794                 if (S_ISREG(mode))
1795                         av |= FILE__OPEN;
1796                 else if (S_ISCHR(mode))
1797                         av |= CHR_FILE__OPEN;
1798                 else if (S_ISBLK(mode))
1799                         av |= BLK_FILE__OPEN;
1800                 else if (S_ISFIFO(mode))
1801                         av |= FIFO_FILE__OPEN;
1802                 else if (S_ISDIR(mode))
1803                         av |= DIR__OPEN;
1804                 else
1805                         printk(KERN_ERR "SELinux: WARNING: inside %s with "
1806                                 "unknown mode:%o\n", __func__, mode);
1807         }
1808         return av;
1809 }
1810
1811 /* Hook functions begin here. */
1812
1813 static int selinux_ptrace_may_access(struct task_struct *child,
1814                                      unsigned int mode)
1815 {
1816         int rc;
1817
1818         rc = secondary_ops->ptrace_may_access(child, mode);
1819         if (rc)
1820                 return rc;
1821
1822         if (mode == PTRACE_MODE_READ) {
1823                 u32 sid = current_sid();
1824                 u32 csid = task_sid(child);
1825                 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
1826         }
1827
1828         return current_has_perm(child, PROCESS__PTRACE);
1829 }
1830
1831 static int selinux_ptrace_traceme(struct task_struct *parent)
1832 {
1833         int rc;
1834
1835         rc = secondary_ops->ptrace_traceme(parent);
1836         if (rc)
1837                 return rc;
1838
1839         return task_has_perm(parent, current, PROCESS__PTRACE);
1840 }
1841
1842 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1843                           kernel_cap_t *inheritable, kernel_cap_t *permitted)
1844 {
1845         int error;
1846
1847         error = current_has_perm(target, PROCESS__GETCAP);
1848         if (error)
1849                 return error;
1850
1851         return secondary_ops->capget(target, effective, inheritable, permitted);
1852 }
1853
1854 static int selinux_capset(struct cred *new, const struct cred *old,
1855                           const kernel_cap_t *effective,
1856                           const kernel_cap_t *inheritable,
1857                           const kernel_cap_t *permitted)
1858 {
1859         int error;
1860
1861         error = secondary_ops->capset(new, old,
1862                                       effective, inheritable, permitted);
1863         if (error)
1864                 return error;
1865
1866         return cred_has_perm(old, new, PROCESS__SETCAP);
1867 }
1868
1869 static int selinux_capable(struct task_struct *tsk, const struct cred *cred,
1870                            int cap, int audit)
1871 {
1872         int rc;
1873
1874         rc = secondary_ops->capable(tsk, cred, cap, audit);
1875         if (rc)
1876                 return rc;
1877
1878         return task_has_capability(tsk, cred, cap, audit);
1879 }
1880
1881 static int selinux_sysctl_get_sid(ctl_table *table, u16 tclass, u32 *sid)
1882 {
1883         int buflen, rc;
1884         char *buffer, *path, *end;
1885
1886         rc = -ENOMEM;
1887         buffer = (char *)__get_free_page(GFP_KERNEL);
1888         if (!buffer)
1889                 goto out;
1890
1891         buflen = PAGE_SIZE;
1892         end = buffer+buflen;
1893         *--end = '\0';
1894         buflen--;
1895         path = end-1;
1896         *path = '/';
1897         while (table) {
1898                 const char *name = table->procname;
1899                 size_t namelen = strlen(name);
1900                 buflen -= namelen + 1;
1901                 if (buflen < 0)
1902                         goto out_free;
1903                 end -= namelen;
1904                 memcpy(end, name, namelen);
1905                 *--end = '/';
1906                 path = end;
1907                 table = table->parent;
1908         }
1909         buflen -= 4;
1910         if (buflen < 0)
1911                 goto out_free;
1912         end -= 4;
1913         memcpy(end, "/sys", 4);
1914         path = end;
1915         rc = security_genfs_sid("proc", path, tclass, sid);
1916 out_free:
1917         free_page((unsigned long)buffer);
1918 out:
1919         return rc;
1920 }
1921
1922 static int selinux_sysctl(ctl_table *table, int op)
1923 {
1924         int error = 0;
1925         u32 av;
1926         u32 tsid, sid;
1927         int rc;
1928
1929         rc = secondary_ops->sysctl(table, op);
1930         if (rc)
1931                 return rc;
1932
1933         sid = current_sid();
1934
1935         rc = selinux_sysctl_get_sid(table, (op == 0001) ?
1936                                     SECCLASS_DIR : SECCLASS_FILE, &tsid);
1937         if (rc) {
1938                 /* Default to the well-defined sysctl SID. */
1939                 tsid = SECINITSID_SYSCTL;
1940         }
1941
1942         /* The op values are "defined" in sysctl.c, thereby creating
1943          * a bad coupling between this module and sysctl.c */
1944         if (op == 001) {
1945                 error = avc_has_perm(sid, tsid,
1946                                      SECCLASS_DIR, DIR__SEARCH, NULL);
1947         } else {
1948                 av = 0;
1949                 if (op & 004)
1950                         av |= FILE__READ;
1951                 if (op & 002)
1952                         av |= FILE__WRITE;
1953                 if (av)
1954                         error = avc_has_perm(sid, tsid,
1955                                              SECCLASS_FILE, av, NULL);
1956         }
1957
1958         return error;
1959 }
1960
1961 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1962 {
1963         const struct cred *cred = current_cred();
1964         int rc = 0;
1965
1966         if (!sb)
1967                 return 0;
1968
1969         switch (cmds) {
1970         case Q_SYNC:
1971         case Q_QUOTAON:
1972         case Q_QUOTAOFF:
1973         case Q_SETINFO:
1974         case Q_SETQUOTA:
1975                 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
1976                 break;
1977         case Q_GETFMT:
1978         case Q_GETINFO:
1979         case Q_GETQUOTA:
1980                 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
1981                 break;
1982         default:
1983                 rc = 0;  /* let the kernel handle invalid cmds */
1984                 break;
1985         }
1986         return rc;
1987 }
1988
1989 static int selinux_quota_on(struct dentry *dentry)
1990 {
1991         const struct cred *cred = current_cred();
1992
1993         return dentry_has_perm(cred, NULL, dentry, FILE__QUOTAON);
1994 }
1995
1996 static int selinux_syslog(int type)
1997 {
1998         int rc;
1999
2000         rc = secondary_ops->syslog(type);
2001         if (rc)
2002                 return rc;
2003
2004         switch (type) {
2005         case 3:         /* Read last kernel messages */
2006         case 10:        /* Return size of the log buffer */
2007                 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
2008                 break;
2009         case 6:         /* Disable logging to console */
2010         case 7:         /* Enable logging to console */
2011         case 8:         /* Set level of messages printed to console */
2012                 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
2013                 break;
2014         case 0:         /* Close log */
2015         case 1:         /* Open log */
2016         case 2:         /* Read from log */
2017         case 4:         /* Read/clear last kernel messages */
2018         case 5:         /* Clear ring buffer */
2019         default:
2020                 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
2021                 break;
2022         }
2023         return rc;
2024 }
2025
2026 /*
2027  * Check that a process has enough memory to allocate a new virtual
2028  * mapping. 0 means there is enough memory for the allocation to
2029  * succeed and -ENOMEM implies there is not.
2030  *
2031  * Note that secondary_ops->capable and task_has_perm_noaudit return 0
2032  * if the capability is granted, but __vm_enough_memory requires 1 if
2033  * the capability is granted.
2034  *
2035  * Do not audit the selinux permission check, as this is applied to all
2036  * processes that allocate mappings.
2037  */
2038 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
2039 {
2040         int rc, cap_sys_admin = 0;
2041
2042         rc = selinux_capable(current, current_cred(), CAP_SYS_ADMIN,
2043                              SECURITY_CAP_NOAUDIT);
2044         if (rc == 0)
2045                 cap_sys_admin = 1;
2046
2047         return __vm_enough_memory(mm, pages, cap_sys_admin);
2048 }
2049
2050 /* binprm security operations */
2051
2052 static int selinux_bprm_set_creds(struct linux_binprm *bprm)
2053 {
2054         const struct task_security_struct *old_tsec;
2055         struct task_security_struct *new_tsec;
2056         struct inode_security_struct *isec;
2057         struct avc_audit_data ad;
2058         struct inode *inode = bprm->file->f_path.dentry->d_inode;
2059         int rc;
2060
2061         rc = secondary_ops->bprm_set_creds(bprm);
2062         if (rc)
2063                 return rc;
2064
2065         /* SELinux context only depends on initial program or script and not
2066          * the script interpreter */
2067         if (bprm->cred_prepared)
2068                 return 0;
2069
2070         old_tsec = current_security();
2071         new_tsec = bprm->cred->security;
2072         isec = inode->i_security;
2073
2074         /* Default to the current task SID. */
2075         new_tsec->sid = old_tsec->sid;
2076         new_tsec->osid = old_tsec->sid;
2077
2078         /* Reset fs, key, and sock SIDs on execve. */
2079         new_tsec->create_sid = 0;
2080         new_tsec->keycreate_sid = 0;
2081         new_tsec->sockcreate_sid = 0;
2082
2083         if (old_tsec->exec_sid) {
2084                 new_tsec->sid = old_tsec->exec_sid;
2085                 /* Reset exec SID on execve. */
2086                 new_tsec->exec_sid = 0;
2087         } else {
2088                 /* Check for a default transition on this program. */
2089                 rc = security_transition_sid(old_tsec->sid, isec->sid,
2090                                              SECCLASS_PROCESS, &new_tsec->sid);
2091                 if (rc)
2092                         return rc;
2093         }
2094
2095         AVC_AUDIT_DATA_INIT(&ad, FS);
2096         ad.u.fs.path = bprm->file->f_path;
2097
2098         if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
2099                 new_tsec->sid = old_tsec->sid;
2100
2101         if (new_tsec->sid == old_tsec->sid) {
2102                 rc = avc_has_perm(old_tsec->sid, isec->sid,
2103                                   SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2104                 if (rc)
2105                         return rc;
2106         } else {
2107                 /* Check permissions for the transition. */
2108                 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2109                                   SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2110                 if (rc)
2111                         return rc;
2112
2113                 rc = avc_has_perm(new_tsec->sid, isec->sid,
2114                                   SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2115                 if (rc)
2116                         return rc;
2117
2118                 /* Check for shared state */
2119                 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2120                         rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2121                                           SECCLASS_PROCESS, PROCESS__SHARE,
2122                                           NULL);
2123                         if (rc)
2124                                 return -EPERM;
2125                 }
2126
2127                 /* Make sure that anyone attempting to ptrace over a task that
2128                  * changes its SID has the appropriate permit */
2129                 if (bprm->unsafe &
2130                     (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2131                         struct task_struct *tracer;
2132                         struct task_security_struct *sec;
2133                         u32 ptsid = 0;
2134
2135                         rcu_read_lock();
2136                         tracer = tracehook_tracer_task(current);
2137                         if (likely(tracer != NULL)) {
2138                                 sec = __task_cred(tracer)->security;
2139                                 ptsid = sec->sid;
2140                         }
2141                         rcu_read_unlock();
2142
2143                         if (ptsid != 0) {
2144                                 rc = avc_has_perm(ptsid, new_tsec->sid,
2145                                                   SECCLASS_PROCESS,
2146                                                   PROCESS__PTRACE, NULL);
2147                                 if (rc)
2148                                         return -EPERM;
2149                         }
2150                 }
2151
2152                 /* Clear any possibly unsafe personality bits on exec: */
2153                 bprm->per_clear |= PER_CLEAR_ON_SETID;
2154         }
2155
2156         return 0;
2157 }
2158
2159 static int selinux_bprm_check_security(struct linux_binprm *bprm)
2160 {
2161         return secondary_ops->bprm_check_security(bprm);
2162 }
2163
2164 static int selinux_bprm_secureexec(struct linux_binprm *bprm)
2165 {
2166         const struct cred *cred = current_cred();
2167         const struct task_security_struct *tsec = cred->security;
2168         u32 sid, osid;
2169         int atsecure = 0;
2170
2171         sid = tsec->sid;
2172         osid = tsec->osid;
2173
2174         if (osid != sid) {
2175                 /* Enable secure mode for SIDs transitions unless
2176                    the noatsecure permission is granted between
2177                    the two SIDs, i.e. ahp returns 0. */
2178                 atsecure = avc_has_perm(osid, sid,
2179                                         SECCLASS_PROCESS,
2180                                         PROCESS__NOATSECURE, NULL);
2181         }
2182
2183         return (atsecure || secondary_ops->bprm_secureexec(bprm));
2184 }
2185
2186 extern struct vfsmount *selinuxfs_mount;
2187 extern struct dentry *selinux_null;
2188
2189 /* Derived from fs/exec.c:flush_old_files. */
2190 static inline void flush_unauthorized_files(const struct cred *cred,
2191                                             struct files_struct *files)
2192 {
2193         struct avc_audit_data ad;
2194         struct file *file, *devnull = NULL;
2195         struct tty_struct *tty;
2196         struct fdtable *fdt;
2197         long j = -1;
2198         int drop_tty = 0;
2199
2200         tty = get_current_tty();
2201         if (tty) {
2202                 file_list_lock();
2203                 if (!list_empty(&tty->tty_files)) {
2204                         struct inode *inode;
2205
2206                         /* Revalidate access to controlling tty.
2207                            Use inode_has_perm on the tty inode directly rather
2208                            than using file_has_perm, as this particular open
2209                            file may belong to another process and we are only
2210                            interested in the inode-based check here. */
2211                         file = list_first_entry(&tty->tty_files, struct file, f_u.fu_list);
2212                         inode = file->f_path.dentry->d_inode;
2213                         if (inode_has_perm(cred, inode,
2214                                            FILE__READ | FILE__WRITE, NULL)) {
2215                                 drop_tty = 1;
2216                         }
2217                 }
2218                 file_list_unlock();
2219                 tty_kref_put(tty);
2220         }
2221         /* Reset controlling tty. */
2222         if (drop_tty)
2223                 no_tty();
2224
2225         /* Revalidate access to inherited open files. */
2226
2227         AVC_AUDIT_DATA_INIT(&ad, FS);
2228
2229         spin_lock(&files->file_lock);
2230         for (;;) {
2231                 unsigned long set, i;
2232                 int fd;
2233
2234                 j++;
2235                 i = j * __NFDBITS;
2236                 fdt = files_fdtable(files);
2237                 if (i >= fdt->max_fds)
2238                         break;
2239                 set = fdt->open_fds->fds_bits[j];
2240                 if (!set)
2241                         continue;
2242                 spin_unlock(&files->file_lock);
2243                 for ( ; set ; i++, set >>= 1) {
2244                         if (set & 1) {
2245                                 file = fget(i);
2246                                 if (!file)
2247                                         continue;
2248                                 if (file_has_perm(cred,
2249                                                   file,
2250                                                   file_to_av(file))) {
2251                                         sys_close(i);
2252                                         fd = get_unused_fd();
2253                                         if (fd != i) {
2254                                                 if (fd >= 0)
2255                                                         put_unused_fd(fd);
2256                                                 fput(file);
2257                                                 continue;
2258                                         }
2259                                         if (devnull) {
2260                                                 get_file(devnull);
2261                                         } else {
2262                                                 devnull = dentry_open(
2263                                                         dget(selinux_null),
2264                                                         mntget(selinuxfs_mount),
2265                                                         O_RDWR, cred);
2266                                                 if (IS_ERR(devnull)) {
2267                                                         devnull = NULL;
2268                                                         put_unused_fd(fd);
2269                                                         fput(file);
2270                                                         continue;
2271                                                 }
2272                                         }
2273                                         fd_install(fd, devnull);
2274                                 }
2275                                 fput(file);
2276                         }
2277                 }
2278                 spin_lock(&files->file_lock);
2279
2280         }
2281         spin_unlock(&files->file_lock);
2282 }
2283
2284 /*
2285  * Prepare a process for imminent new credential changes due to exec
2286  */
2287 static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2288 {
2289         struct task_security_struct *new_tsec;
2290         struct rlimit *rlim, *initrlim;
2291         int rc, i;
2292
2293         secondary_ops->bprm_committing_creds(bprm);
2294
2295         new_tsec = bprm->cred->security;
2296         if (new_tsec->sid == new_tsec->osid)
2297                 return;
2298
2299         /* Close files for which the new task SID is not authorized. */
2300         flush_unauthorized_files(bprm->cred, current->files);
2301
2302         /* Always clear parent death signal on SID transitions. */
2303         current->pdeath_signal = 0;
2304
2305         /* Check whether the new SID can inherit resource limits from the old
2306          * SID.  If not, reset all soft limits to the lower of the current
2307          * task's hard limit and the init task's soft limit.
2308          *
2309          * Note that the setting of hard limits (even to lower them) can be
2310          * controlled by the setrlimit check.  The inclusion of the init task's
2311          * soft limit into the computation is to avoid resetting soft limits
2312          * higher than the default soft limit for cases where the default is
2313          * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2314          */
2315         rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2316                           PROCESS__RLIMITINH, NULL);
2317         if (rc) {
2318                 for (i = 0; i < RLIM_NLIMITS; i++) {
2319                         rlim = current->signal->rlim + i;
2320                         initrlim = init_task.signal->rlim + i;
2321                         rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2322                 }
2323                 update_rlimit_cpu(rlim->rlim_cur);
2324         }
2325 }
2326
2327 /*
2328  * Clean up the process immediately after the installation of new credentials
2329  * due to exec
2330  */
2331 static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2332 {
2333         const struct task_security_struct *tsec = current_security();
2334         struct itimerval itimer;
2335         struct sighand_struct *psig;
2336         u32 osid, sid;
2337         int rc, i;
2338         unsigned long flags;
2339
2340         secondary_ops->bprm_committed_creds(bprm);
2341
2342         osid = tsec->osid;
2343         sid = tsec->sid;
2344
2345         if (sid == osid)
2346                 return;
2347
2348         /* Check whether the new SID can inherit signal state from the old SID.
2349          * If not, clear itimers to avoid subsequent signal generation and
2350          * flush and unblock signals.
2351          *
2352          * This must occur _after_ the task SID has been updated so that any
2353          * kill done after the flush will be checked against the new SID.
2354          */
2355         rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2356         if (rc) {
2357                 memset(&itimer, 0, sizeof itimer);
2358                 for (i = 0; i < 3; i++)
2359                         do_setitimer(i, &itimer, NULL);
2360                 flush_signals(current);
2361                 spin_lock_irq(&current->sighand->siglock);
2362                 flush_signal_handlers(current, 1);
2363                 sigemptyset(&current->blocked);
2364                 recalc_sigpending();
2365                 spin_unlock_irq(&current->sighand->siglock);
2366         }
2367
2368         /* Wake up the parent if it is waiting so that it can recheck
2369          * wait permission to the new task SID. */
2370         read_lock_irq(&tasklist_lock);
2371         psig = current->parent->sighand;
2372         spin_lock_irqsave(&psig->siglock, flags);
2373         wake_up_interruptible(&current->parent->signal->wait_chldexit);
2374         spin_unlock_irqrestore(&psig->siglock, flags);
2375         read_unlock_irq(&tasklist_lock);
2376 }
2377
2378 /* superblock security operations */
2379
2380 static int selinux_sb_alloc_security(struct super_block *sb)
2381 {
2382         return superblock_alloc_security(sb);
2383 }
2384
2385 static void selinux_sb_free_security(struct super_block *sb)
2386 {
2387         superblock_free_security(sb);
2388 }
2389
2390 static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2391 {
2392         if (plen > olen)
2393                 return 0;
2394
2395         return !memcmp(prefix, option, plen);
2396 }
2397
2398 static inline int selinux_option(char *option, int len)
2399 {
2400         return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2401                 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2402                 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2403                 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len));
2404 }
2405
2406 static inline void take_option(char **to, char *from, int *first, int len)
2407 {
2408         if (!*first) {
2409                 **to = ',';
2410                 *to += 1;
2411         } else
2412                 *first = 0;
2413         memcpy(*to, from, len);
2414         *to += len;
2415 }
2416
2417 static inline void take_selinux_option(char **to, char *from, int *first,
2418                                        int len)
2419 {
2420         int current_size = 0;
2421
2422         if (!*first) {
2423                 **to = '|';
2424                 *to += 1;
2425         } else
2426                 *first = 0;
2427
2428         while (current_size < len) {
2429                 if (*from != '"') {
2430                         **to = *from;
2431                         *to += 1;
2432                 }
2433                 from += 1;
2434                 current_size += 1;
2435         }
2436 }
2437
2438 static int selinux_sb_copy_data(char *orig, char *copy)
2439 {
2440         int fnosec, fsec, rc = 0;
2441         char *in_save, *in_curr, *in_end;
2442         char *sec_curr, *nosec_save, *nosec;
2443         int open_quote = 0;
2444
2445         in_curr = orig;
2446         sec_curr = copy;
2447
2448         nosec = (char *)get_zeroed_page(GFP_KERNEL);
2449         if (!nosec) {
2450                 rc = -ENOMEM;
2451                 goto out;
2452         }
2453
2454         nosec_save = nosec;
2455         fnosec = fsec = 1;
2456         in_save = in_end = orig;
2457
2458         do {
2459                 if (*in_end == '"')
2460                         open_quote = !open_quote;
2461                 if ((*in_end == ',' && open_quote == 0) ||
2462                                 *in_end == '\0') {
2463                         int len = in_end - in_curr;
2464
2465                         if (selinux_option(in_curr, len))
2466                                 take_selinux_option(&sec_curr, in_curr, &fsec, len);
2467                         else
2468                                 take_option(&nosec, in_curr, &fnosec, len);
2469
2470                         in_curr = in_end + 1;
2471                 }
2472         } while (*in_end++);
2473
2474         strcpy(in_save, nosec_save);
2475         free_page((unsigned long)nosec_save);
2476 out:
2477         return rc;
2478 }
2479
2480 static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
2481 {
2482         const struct cred *cred = current_cred();
2483         struct avc_audit_data ad;
2484         int rc;
2485
2486         rc = superblock_doinit(sb, data);
2487         if (rc)
2488                 return rc;
2489
2490         /* Allow all mounts performed by the kernel */
2491         if (flags & MS_KERNMOUNT)
2492                 return 0;
2493
2494         AVC_AUDIT_DATA_INIT(&ad, FS);
2495         ad.u.fs.path.dentry = sb->s_root;
2496         return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2497 }
2498
2499 static int selinux_sb_statfs(struct dentry *dentry)
2500 {
2501         const struct cred *cred = current_cred();
2502         struct avc_audit_data ad;
2503
2504         AVC_AUDIT_DATA_INIT(&ad, FS);
2505         ad.u.fs.path.dentry = dentry->d_sb->s_root;
2506         return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2507 }
2508
2509 static int selinux_mount(char *dev_name,
2510                          struct path *path,
2511                          char *type,
2512                          unsigned long flags,
2513                          void *data)
2514 {
2515         const struct cred *cred = current_cred();
2516         int rc;
2517
2518         rc = secondary_ops->sb_mount(dev_name, path, type, flags, data);
2519         if (rc)
2520                 return rc;
2521
2522         if (flags & MS_REMOUNT)
2523                 return superblock_has_perm(cred, path->mnt->mnt_sb,
2524                                            FILESYSTEM__REMOUNT, NULL);
2525         else
2526                 return dentry_has_perm(cred, path->mnt, path->dentry,
2527                                        FILE__MOUNTON);
2528 }
2529
2530 static int selinux_umount(struct vfsmount *mnt, int flags)
2531 {
2532         const struct cred *cred = current_cred();
2533         int rc;
2534
2535         rc = secondary_ops->sb_umount(mnt, flags);
2536         if (rc)
2537                 return rc;
2538
2539         return superblock_has_perm(cred, mnt->mnt_sb,
2540                                    FILESYSTEM__UNMOUNT, NULL);
2541 }
2542
2543 /* inode security operations */
2544
2545 static int selinux_inode_alloc_security(struct inode *inode)
2546 {
2547         return inode_alloc_security(inode);
2548 }
2549
2550 static void selinux_inode_free_security(struct inode *inode)
2551 {
2552         inode_free_security(inode);
2553 }
2554
2555 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2556                                        char **name, void **value,
2557                                        size_t *len)
2558 {
2559         const struct cred *cred = current_cred();
2560         const struct task_security_struct *tsec = cred->security;
2561         struct inode_security_struct *dsec;
2562         struct superblock_security_struct *sbsec;
2563         u32 sid, newsid, clen;
2564         int rc;
2565         char *namep = NULL, *context;
2566
2567         dsec = dir->i_security;
2568         sbsec = dir->i_sb->s_security;
2569
2570         sid = tsec->sid;
2571         newsid = tsec->create_sid;
2572
2573         if (!newsid || sbsec->behavior == SECURITY_FS_USE_MNTPOINT) {
2574                 rc = security_transition_sid(sid, dsec->sid,
2575                                              inode_mode_to_security_class(inode->i_mode),
2576                                              &newsid);
2577                 if (rc) {
2578                         printk(KERN_WARNING "%s:  "
2579                                "security_transition_sid failed, rc=%d (dev=%s "
2580                                "ino=%ld)\n",
2581                                __func__,
2582                                -rc, inode->i_sb->s_id, inode->i_ino);
2583                         return rc;
2584                 }
2585         }
2586
2587         /* Possibly defer initialization to selinux_complete_init. */
2588         if (sbsec->initialized) {
2589                 struct inode_security_struct *isec = inode->i_security;
2590                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2591                 isec->sid = newsid;
2592                 isec->initialized = 1;
2593         }
2594
2595         if (!ss_initialized || sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2596                 return -EOPNOTSUPP;
2597
2598         if (name) {
2599                 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
2600                 if (!namep)
2601                         return -ENOMEM;
2602                 *name = namep;
2603         }
2604
2605         if (value && len) {
2606                 rc = security_sid_to_context_force(newsid, &context, &clen);
2607                 if (rc) {
2608                         kfree(namep);
2609                         return rc;
2610                 }
2611                 *value = context;
2612                 *len = clen;
2613         }
2614
2615         return 0;
2616 }
2617
2618 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask)
2619 {
2620         return may_create(dir, dentry, SECCLASS_FILE);
2621 }
2622
2623 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2624 {
2625         int rc;
2626
2627         rc = secondary_ops->inode_link(old_dentry, dir, new_dentry);
2628         if (rc)
2629                 return rc;
2630         return may_link(dir, old_dentry, MAY_LINK);
2631 }
2632
2633 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2634 {
2635         int rc;
2636
2637         rc = secondary_ops->inode_unlink(dir, dentry);
2638         if (rc)
2639                 return rc;
2640         return may_link(dir, dentry, MAY_UNLINK);
2641 }
2642
2643 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2644 {
2645         return may_create(dir, dentry, SECCLASS_LNK_FILE);
2646 }
2647
2648 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask)
2649 {
2650         return may_create(dir, dentry, SECCLASS_DIR);
2651 }
2652
2653 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2654 {
2655         return may_link(dir, dentry, MAY_RMDIR);
2656 }
2657
2658 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
2659 {
2660         int rc;
2661
2662         rc = secondary_ops->inode_mknod(dir, dentry, mode, dev);
2663         if (rc)
2664                 return rc;
2665
2666         return may_create(dir, dentry, inode_mode_to_security_class(mode));
2667 }
2668
2669 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2670                                 struct inode *new_inode, struct dentry *new_dentry)
2671 {
2672         return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2673 }
2674
2675 static int selinux_inode_readlink(struct dentry *dentry)
2676 {
2677         const struct cred *cred = current_cred();
2678
2679         return dentry_has_perm(cred, NULL, dentry, FILE__READ);
2680 }
2681
2682 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2683 {
2684         const struct cred *cred = current_cred();
2685         int rc;
2686
2687         rc = secondary_ops->inode_follow_link(dentry, nameidata);
2688         if (rc)
2689                 return rc;
2690         return dentry_has_perm(cred, NULL, dentry, FILE__READ);
2691 }
2692
2693 static int selinux_inode_permission(struct inode *inode, int mask)
2694 {
2695         const struct cred *cred = current_cred();
2696         int rc;
2697
2698         rc = secondary_ops->inode_permission(inode, mask);
2699         if (rc)
2700                 return rc;
2701
2702         if (!mask) {
2703                 /* No permission to check.  Existence test. */
2704                 return 0;
2705         }
2706
2707         return inode_has_perm(cred, inode,
2708                               file_mask_to_av(inode->i_mode, mask), NULL);
2709 }
2710
2711 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2712 {
2713         const struct cred *cred = current_cred();
2714         int rc;
2715
2716         rc = secondary_ops->inode_setattr(dentry, iattr);
2717         if (rc)
2718                 return rc;
2719
2720         if (iattr->ia_valid & ATTR_FORCE)
2721                 return 0;
2722
2723         if (iattr->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2724                                ATTR_ATIME_SET | ATTR_MTIME_SET))
2725                 return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR);
2726
2727         return dentry_has_perm(cred, NULL, dentry, FILE__WRITE);
2728 }
2729
2730 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2731 {
2732         const struct cred *cred = current_cred();
2733
2734         return dentry_has_perm(cred, mnt, dentry, FILE__GETATTR);
2735 }
2736
2737 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2738 {
2739         const struct cred *cred = current_cred();
2740
2741         if (!strncmp(name, XATTR_SECURITY_PREFIX,
2742                      sizeof XATTR_SECURITY_PREFIX - 1)) {
2743                 if (!strcmp(name, XATTR_NAME_CAPS)) {
2744                         if (!capable(CAP_SETFCAP))
2745                                 return -EPERM;
2746                 } else if (!capable(CAP_SYS_ADMIN)) {
2747                         /* A different attribute in the security namespace.
2748                            Restrict to administrator. */
2749                         return -EPERM;
2750                 }
2751         }
2752
2753         /* Not an attribute we recognize, so just check the
2754            ordinary setattr permission. */
2755         return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR);
2756 }
2757
2758 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2759                                   const void *value, size_t size, int flags)
2760 {
2761         struct inode *inode = dentry->d_inode;
2762         struct inode_security_struct *isec = inode->i_security;
2763         struct superblock_security_struct *sbsec;
2764         struct avc_audit_data ad;
2765         u32 newsid, sid = current_sid();
2766         int rc = 0;
2767
2768         if (strcmp(name, XATTR_NAME_SELINUX))
2769                 return selinux_inode_setotherxattr(dentry, name);
2770
2771         sbsec = inode->i_sb->s_security;
2772         if (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)
2773                 return -EOPNOTSUPP;
2774
2775         if (!is_owner_or_cap(inode))
2776                 return -EPERM;
2777
2778         AVC_AUDIT_DATA_INIT(&ad, FS);
2779         ad.u.fs.path.dentry = dentry;
2780
2781         rc = avc_has_perm(sid, isec->sid, isec->sclass,
2782                           FILE__RELABELFROM, &ad);
2783         if (rc)
2784                 return rc;
2785
2786         rc = security_context_to_sid(value, size, &newsid);
2787         if (rc == -EINVAL) {
2788                 if (!capable(CAP_MAC_ADMIN))
2789                         return rc;
2790                 rc = security_context_to_sid_force(value, size, &newsid);
2791         }
2792         if (rc)
2793                 return rc;
2794
2795         rc = avc_has_perm(sid, newsid, isec->sclass,
2796                           FILE__RELABELTO, &ad);
2797         if (rc)
2798                 return rc;
2799
2800         rc = security_validate_transition(isec->sid, newsid, sid,
2801                                           isec->sclass);
2802         if (rc)
2803                 return rc;
2804
2805         return avc_has_perm(newsid,
2806                             sbsec->sid,
2807                             SECCLASS_FILESYSTEM,
2808                             FILESYSTEM__ASSOCIATE,
2809                             &ad);
2810 }
2811
2812 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2813                                         const void *value, size_t size,
2814                                         int flags)
2815 {
2816         struct inode *inode = dentry->d_inode;
2817         struct inode_security_struct *isec = inode->i_security;
2818         u32 newsid;
2819         int rc;
2820
2821         if (strcmp(name, XATTR_NAME_SELINUX)) {
2822                 /* Not an attribute we recognize, so nothing to do. */
2823                 return;
2824         }
2825
2826         rc = security_context_to_sid_force(value, size, &newsid);
2827         if (rc) {
2828                 printk(KERN_ERR "SELinux:  unable to map context to SID"
2829                        "for (%s, %lu), rc=%d\n",
2830                        inode->i_sb->s_id, inode->i_ino, -rc);
2831                 return;
2832         }
2833
2834         isec->sid = newsid;
2835         return;
2836 }
2837
2838 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
2839 {
2840         const struct cred *cred = current_cred();
2841
2842         return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR);
2843 }
2844
2845 static int selinux_inode_listxattr(struct dentry *dentry)
2846 {
2847         const struct cred *cred = current_cred();
2848
2849         return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR);
2850 }
2851
2852 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
2853 {
2854         if (strcmp(name, XATTR_NAME_SELINUX))
2855                 return selinux_inode_setotherxattr(dentry, name);
2856
2857         /* No one is allowed to remove a SELinux security label.
2858            You can change the label, but all data must be labeled. */
2859         return -EACCES;
2860 }
2861
2862 /*
2863  * Copy the inode security context value to the user.
2864  *
2865  * Permission check is handled by selinux_inode_getxattr hook.
2866  */
2867 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
2868 {
2869         u32 size;
2870         int error;
2871         char *context = NULL;
2872         struct inode_security_struct *isec = inode->i_security;
2873
2874         if (strcmp(name, XATTR_SELINUX_SUFFIX))
2875                 return -EOPNOTSUPP;
2876
2877         /*
2878          * If the caller has CAP_MAC_ADMIN, then get the raw context
2879          * value even if it is not defined by current policy; otherwise,
2880          * use the in-core value under current policy.
2881          * Use the non-auditing forms of the permission checks since
2882          * getxattr may be called by unprivileged processes commonly
2883          * and lack of permission just means that we fall back to the
2884          * in-core context value, not a denial.
2885          */
2886         error = selinux_capable(current, current_cred(), CAP_MAC_ADMIN,
2887                                 SECURITY_CAP_NOAUDIT);
2888         if (!error)
2889                 error = security_sid_to_context_force(isec->sid, &context,
2890                                                       &size);
2891         else
2892                 error = security_sid_to_context(isec->sid, &context, &size);
2893         if (error)
2894                 return error;
2895         error = size;
2896         if (alloc) {
2897                 *buffer = context;
2898                 goto out_nofree;
2899         }
2900         kfree(context);
2901 out_nofree:
2902         return error;
2903 }
2904
2905 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2906                                      const void *value, size_t size, int flags)
2907 {
2908         struct inode_security_struct *isec = inode->i_security;
2909         u32 newsid;
2910         int rc;
2911
2912         if (strcmp(name, XATTR_SELINUX_SUFFIX))
2913                 return -EOPNOTSUPP;
2914
2915         if (!value || !size)
2916                 return -EACCES;
2917
2918         rc = security_context_to_sid((void *)value, size, &newsid);
2919         if (rc)
2920                 return rc;
2921
2922         isec->sid = newsid;
2923         return 0;
2924 }
2925
2926 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2927 {
2928         const int len = sizeof(XATTR_NAME_SELINUX);
2929         if (buffer && len <= buffer_size)
2930                 memcpy(buffer, XATTR_NAME_SELINUX, len);
2931         return len;
2932 }
2933
2934 static int selinux_inode_need_killpriv(struct dentry *dentry)
2935 {
2936         return secondary_ops->inode_need_killpriv(dentry);
2937 }
2938
2939 static int selinux_inode_killpriv(struct dentry *dentry)
2940 {
2941         return secondary_ops->inode_killpriv(dentry);
2942 }
2943
2944 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2945 {
2946         struct inode_security_struct *isec = inode->i_security;
2947         *secid = isec->sid;
2948 }
2949
2950 /* file security operations */
2951
2952 static int selinux_revalidate_file_permission(struct file *file, int mask)
2953 {
2954         const struct cred *cred = current_cred();
2955         int rc;
2956         struct inode *inode = file->f_path.dentry->d_inode;
2957
2958         if (!mask) {
2959                 /* No permission to check.  Existence test. */
2960                 return 0;
2961         }
2962
2963         /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2964         if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2965                 mask |= MAY_APPEND;
2966
2967         rc = file_has_perm(cred, file,
2968                            file_mask_to_av(inode->i_mode, mask));
2969         if (rc)
2970                 return rc;
2971
2972         return selinux_netlbl_inode_permission(inode, mask);
2973 }
2974
2975 static int selinux_file_permission(struct file *file, int mask)
2976 {
2977         struct inode *inode = file->f_path.dentry->d_inode;
2978         struct file_security_struct *fsec = file->f_security;
2979         struct inode_security_struct *isec = inode->i_security;
2980         u32 sid = current_sid();
2981
2982         if (!mask) {
2983                 /* No permission to check.  Existence test. */
2984                 return 0;
2985         }
2986
2987         if (sid == fsec->sid && fsec->isid == isec->sid
2988             && fsec->pseqno == avc_policy_seqno())
2989                 return selinux_netlbl_inode_permission(inode, mask);
2990
2991         return selinux_revalidate_file_permission(file, mask);
2992 }
2993
2994 static int selinux_file_alloc_security(struct file *file)
2995 {
2996         return file_alloc_security(file);
2997 }
2998
2999 static void selinux_file_free_security(struct file *file)
3000 {
3001         file_free_security(file);
3002 }
3003
3004 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
3005                               unsigned long arg)
3006 {
3007         const struct cred *cred = current_cred();
3008         u32 av = 0;
3009
3010         if (_IOC_DIR(cmd) & _IOC_WRITE)
3011                 av |= FILE__WRITE;
3012         if (_IOC_DIR(cmd) & _IOC_READ)
3013                 av |= FILE__READ;
3014         if (!av)
3015                 av = FILE__IOCTL;
3016
3017         return file_has_perm(cred, file, av);
3018 }
3019
3020 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3021 {
3022         const struct cred *cred = current_cred();
3023         int rc = 0;
3024
3025 #ifndef CONFIG_PPC32
3026         if ((prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
3027                 /*
3028                  * We are making executable an anonymous mapping or a
3029                  * private file mapping that will also be writable.
3030                  * This has an additional check.
3031                  */
3032                 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
3033                 if (rc)
3034                         goto error;
3035         }
3036 #endif
3037
3038         if (file) {
3039                 /* read access is always possible with a mapping */
3040                 u32 av = FILE__READ;
3041
3042                 /* write access only matters if the mapping is shared */
3043                 if (shared && (prot & PROT_WRITE))
3044                         av |= FILE__WRITE;
3045
3046                 if (prot & PROT_EXEC)
3047                         av |= FILE__EXECUTE;
3048
3049                 return file_has_perm(cred, file, av);
3050         }
3051
3052 error:
3053         return rc;
3054 }
3055
3056 static int selinux_file_mmap(struct file *file, unsigned long reqprot,
3057                              unsigned long prot, unsigned long flags,
3058                              unsigned long addr, unsigned long addr_only)
3059 {
3060         int rc = 0;
3061         u32 sid = current_sid();
3062
3063         if (addr < mmap_min_addr)
3064                 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3065                                   MEMPROTECT__MMAP_ZERO, NULL);
3066         if (rc || addr_only)
3067                 return rc;
3068
3069         if (selinux_checkreqprot)
3070                 prot = reqprot;
3071
3072         return file_map_prot_check(file, prot,
3073                                    (flags & MAP_TYPE) == MAP_SHARED);
3074 }
3075
3076 static int selinux_file_mprotect(struct vm_area_struct *vma,
3077                                  unsigned long reqprot,
3078                                  unsigned long prot)
3079 {
3080         const struct cred *cred = current_cred();
3081         int rc;
3082
3083         rc = secondary_ops->file_mprotect(vma, reqprot, prot);
3084         if (rc)
3085                 return rc;
3086
3087         if (selinux_checkreqprot)
3088                 prot = reqprot;
3089
3090 #ifndef CONFIG_PPC32
3091         if ((prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3092                 rc = 0;
3093                 if (vma->vm_start >= vma->vm_mm->start_brk &&
3094                     vma->vm_end <= vma->vm_mm->brk) {
3095                         rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3096                 } else if (!vma->vm_file &&
3097                            vma->vm_start <= vma->vm_mm->start_stack &&
3098                            vma->vm_end >= vma->vm_mm->start_stack) {
3099                         rc = current_has_perm(current, PROCESS__EXECSTACK);
3100                 } else if (vma->vm_file && vma->anon_vma) {
3101                         /*
3102                          * We are making executable a file mapping that has
3103                          * had some COW done. Since pages might have been
3104                          * written, check ability to execute the possibly
3105                          * modified content.  This typically should only
3106                          * occur for text relocations.
3107                          */
3108                         rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3109                 }
3110                 if (rc)
3111                         return rc;
3112         }
3113 #endif
3114
3115         return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3116 }
3117
3118 static int selinux_file_lock(struct file *file, unsigned int cmd)
3119 {
3120         const struct cred *cred = current_cred();
3121
3122         return file_has_perm(cred, file, FILE__LOCK);
3123 }
3124
3125 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3126                               unsigned long arg)
3127 {
3128         const struct cred *cred = current_cred();
3129         int err = 0;
3130
3131         switch (cmd) {
3132         case F_SETFL:
3133                 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3134                         err = -EINVAL;
3135                         break;
3136                 }
3137
3138                 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3139                         err = file_has_perm(cred, file, FILE__WRITE);
3140                         break;
3141                 }
3142                 /* fall through */
3143         case F_SETOWN:
3144         case F_SETSIG:
3145         case F_GETFL:
3146         case F_GETOWN:
3147         case F_GETSIG:
3148                 /* Just check FD__USE permission */
3149                 err = file_has_perm(cred, file, 0);
3150                 break;
3151         case F_GETLK:
3152         case F_SETLK:
3153         case F_SETLKW:
3154 #if BITS_PER_LONG == 32
3155         case F_GETLK64:
3156         case F_SETLK64:
3157         case F_SETLKW64:
3158 #endif
3159                 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3160                         err = -EINVAL;
3161                         break;
3162                 }
3163                 err = file_has_perm(cred, file, FILE__LOCK);
3164                 break;
3165         }
3166
3167         return err;
3168 }
3169
3170 static int selinux_file_set_fowner(struct file *file)
3171 {
3172         struct file_security_struct *fsec;
3173
3174         fsec = file->f_security;
3175         fsec->fown_sid = current_sid();
3176
3177         return 0;
3178 }
3179
3180 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3181                                        struct fown_struct *fown, int signum)
3182 {
3183         struct file *file;
3184         u32 sid = current_sid();
3185         u32 perm;
3186         struct file_security_struct *fsec;
3187
3188         /* struct fown_struct is never outside the context of a struct file */
3189         file = container_of(fown, struct file, f_owner);
3190
3191         fsec = file->f_security;
3192
3193         if (!signum)
3194                 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3195         else
3196                 perm = signal_to_av(signum);
3197
3198         return avc_has_perm(fsec->fown_sid, sid,
3199                             SECCLASS_PROCESS, perm, NULL);
3200 }
3201
3202 static int selinux_file_receive(struct file *file)
3203 {
3204         const struct cred *cred = current_cred();
3205
3206         return file_has_perm(cred, file, file_to_av(file));
3207 }
3208
3209 static int selinux_dentry_open(struct file *file, const struct cred *cred)
3210 {
3211         struct file_security_struct *fsec;
3212         struct inode *inode;
3213         struct inode_security_struct *isec;
3214
3215         inode = file->f_path.dentry->d_inode;
3216         fsec = file->f_security;
3217         isec = inode->i_security;
3218         /*
3219          * Save inode label and policy sequence number
3220          * at open-time so that selinux_file_permission
3221          * can determine whether revalidation is necessary.
3222          * Task label is already saved in the file security
3223          * struct as its SID.
3224          */
3225         fsec->isid = isec->sid;
3226         fsec->pseqno = avc_policy_seqno();
3227         /*
3228          * Since the inode label or policy seqno may have changed
3229          * between the selinux_inode_permission check and the saving
3230          * of state above, recheck that access is still permitted.
3231          * Otherwise, access might never be revalidated against the
3232          * new inode label or new policy.
3233          * This check is not redundant - do not remove.
3234          */
3235         return inode_has_perm(cred, inode, open_file_to_av(file), NULL);
3236 }
3237
3238 /* task security operations */
3239
3240 static int selinux_task_create(unsigned long clone_flags)
3241 {
3242         int rc;
3243
3244         rc = secondary_ops->task_create(clone_flags);
3245         if (rc)
3246                 return rc;
3247
3248         return current_has_perm(current, PROCESS__FORK);
3249 }
3250
3251 /*
3252  * detach and free the LSM part of a set of credentials
3253  */
3254 static void selinux_cred_free(struct cred *cred)
3255 {
3256         struct task_security_struct *tsec = cred->security;
3257         cred->security = NULL;
3258         kfree(tsec);
3259 }
3260
3261 /*
3262  * prepare a new set of credentials for modification
3263  */
3264 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3265                                 gfp_t gfp)
3266 {
3267         const struct task_security_struct *old_tsec;
3268         struct task_security_struct *tsec;
3269
3270         old_tsec = old->security;
3271
3272         tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
3273         if (!tsec)
3274                 return -ENOMEM;
3275
3276         new->security = tsec;
3277         return 0;
3278 }
3279
3280 /*
3281  * commit new credentials
3282  */
3283 static void selinux_cred_commit(struct cred *new, const struct cred *old)
3284 {
3285         secondary_ops->cred_commit(new, old);
3286 }
3287
3288 /*
3289  * set the security data for a kernel service
3290  * - all the creation contexts are set to unlabelled
3291  */
3292 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3293 {
3294         struct task_security_struct *tsec = new->security;
3295         u32 sid = current_sid();
3296         int ret;
3297
3298         ret = avc_has_perm(sid, secid,
3299                            SECCLASS_KERNEL_SERVICE,
3300                            KERNEL_SERVICE__USE_AS_OVERRIDE,
3301                            NULL);
3302         if (ret == 0) {
3303                 tsec->sid = secid;
3304                 tsec->create_sid = 0;
3305                 tsec->keycreate_sid = 0;
3306                 tsec->sockcreate_sid = 0;
3307         }
3308         return ret;