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, 2009 Hewlett-Packard Development Company, L.P. 17 * Paul Moore <paul@paul-moore.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/kd.h> 28 #include <linux/kernel.h> 29 #include <linux/tracehook.h> 30 #include <linux/errno.h> 31 #include <linux/ext2_fs.h> 32 #include <linux/sched.h> 33 #include <linux/security.h> 34 #include <linux/xattr.h> 35 #include <linux/capability.h> 36 #include <linux/unistd.h> 37 #include <linux/mm.h> 38 #include <linux/mman.h> 39 #include <linux/slab.h> 40 #include <linux/pagemap.h> 41 #include <linux/proc_fs.h> 42 #include <linux/swap.h> 43 #include <linux/spinlock.h> 44 #include <linux/syscalls.h> 45 #include <linux/dcache.h> 46 #include <linux/file.h> 47 #include <linux/fdtable.h> 48 #include <linux/namei.h> 49 #include <linux/mount.h> 50 #include <linux/netfilter_ipv4.h> 51 #include <linux/netfilter_ipv6.h> 52 #include <linux/tty.h> 53 #include <net/icmp.h> 54 #include <net/ip.h> /* for local_port_range[] */ 55 #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */ 56 #include <net/net_namespace.h> 57 #include <net/netlabel.h> 58 #include <linux/uaccess.h> 59 #include <asm/ioctls.h> 60 #include <linux/atomic.h> 61 #include <linux/bitops.h> 62 #include <linux/interrupt.h> 63 #include <linux/netdevice.h> /* for network interface checks */ 64 #include <linux/netlink.h> 65 #include <linux/tcp.h> 66 #include <linux/udp.h> 67 #include <linux/dccp.h> 68 #include <linux/quota.h> 69 #include <linux/un.h> /* for Unix socket types */ 70 #include <net/af_unix.h> /* for Unix socket types */ 71 #include <linux/parser.h> 72 #include <linux/nfs_mount.h> 73 #include <net/ipv6.h> 74 #include <linux/hugetlb.h> 75 #include <linux/personality.h> 76 #include <linux/audit.h> 77 #include <linux/string.h> 78 #include <linux/selinux.h> 79 #include <linux/mutex.h> 80 #include <linux/posix-timers.h> 81 #include <linux/syslog.h> 82 #include <linux/user_namespace.h> 83 #include <linux/export.h> 84 #include <linux/msg.h> 85 #include <linux/shm.h> 86 87 #include "avc.h" 88 #include "objsec.h" 89 #include "netif.h" 90 #include "netnode.h" 91 #include "netport.h" 92 #include "xfrm.h" 93 #include "netlabel.h" 94 #include "audit.h" 95 #include "avc_ss.h" 96 97 #define NUM_SEL_MNT_OPTS 5 98 99 extern struct security_operations *security_ops; 100 101 /* SECMARK reference count */ 102 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0); 103 104 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP 105 int selinux_enforcing; 106 107 static int __init enforcing_setup(char *str) 108 { 109 unsigned long enforcing; 110 if (!strict_strtoul(str, 0, &enforcing)) 111 selinux_enforcing = enforcing ? 1 : 0; 112 return 1; 113 } 114 __setup("enforcing=", enforcing_setup); 115 #endif 116 117 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM 118 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE; 119 120 static int __init selinux_enabled_setup(char *str) 121 { 122 unsigned long enabled; 123 if (!strict_strtoul(str, 0, &enabled)) 124 selinux_enabled = enabled ? 1 : 0; 125 return 1; 126 } 127 __setup("selinux=", selinux_enabled_setup); 128 #else 129 int selinux_enabled = 1; 130 #endif 131 132 static struct kmem_cache *sel_inode_cache; 133 134 /** 135 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled 136 * 137 * Description: 138 * This function checks the SECMARK reference counter to see if any SECMARK 139 * targets are currently configured, if the reference counter is greater than 140 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is 141 * enabled, false (0) if SECMARK is disabled. 142 * 143 */ 144 static int selinux_secmark_enabled(void) 145 { 146 return (atomic_read(&selinux_secmark_refcount) > 0); 147 } 148 149 /* 150 * initialise the security for the init task 151 */ 152 static void cred_init_security(void) 153 { 154 struct cred *cred = (struct cred *) current->real_cred; 155 struct task_security_struct *tsec; 156 157 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL); 158 if (!tsec) 159 panic("SELinux: Failed to initialize initial task.\n"); 160 161 tsec->osid = tsec->sid = SECINITSID_KERNEL; 162 cred->security = tsec; 163 } 164 165 /* 166 * get the security ID of a set of credentials 167 */ 168 static inline u32 cred_sid(const struct cred *cred) 169 { 170 const struct task_security_struct *tsec; 171 172 tsec = cred->security; 173 return tsec->sid; 174 } 175 176 /* 177 * get the objective security ID of a task 178 */ 179 static inline u32 task_sid(const struct task_struct *task) 180 { 181 u32 sid; 182 183 rcu_read_lock(); 184 sid = cred_sid(__task_cred(task)); 185 rcu_read_unlock(); 186 return sid; 187 } 188 189 /* 190 * get the subjective security ID of the current task 191 */ 192 static inline u32 current_sid(void) 193 { 194 const struct task_security_struct *tsec = current_security(); 195 196 return tsec->sid; 197 } 198 199 /* Allocate and free functions for each kind of security blob. */ 200 201 static int inode_alloc_security(struct inode *inode) 202 { 203 struct inode_security_struct *isec; 204 u32 sid = current_sid(); 205 206 isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS); 207 if (!isec) 208 return -ENOMEM; 209 210 mutex_init(&isec->lock); 211 INIT_LIST_HEAD(&isec->list); 212 isec->inode = inode; 213 isec->sid = SECINITSID_UNLABELED; 214 isec->sclass = SECCLASS_FILE; 215 isec->task_sid = sid; 216 inode->i_security = isec; 217 218 return 0; 219 } 220 221 static void inode_free_security(struct inode *inode) 222 { 223 struct inode_security_struct *isec = inode->i_security; 224 struct superblock_security_struct *sbsec = inode->i_sb->s_security; 225 226 spin_lock(&sbsec->isec_lock); 227 if (!list_empty(&isec->list)) 228 list_del_init(&isec->list); 229 spin_unlock(&sbsec->isec_lock); 230 231 inode->i_security = NULL; 232 kmem_cache_free(sel_inode_cache, isec); 233 } 234 235 static int file_alloc_security(struct file *file) 236 { 237 struct file_security_struct *fsec; 238 u32 sid = current_sid(); 239 240 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL); 241 if (!fsec) 242 return -ENOMEM; 243 244 fsec->sid = sid; 245 fsec->fown_sid = sid; 246 file->f_security = fsec; 247 248 return 0; 249 } 250 251 static void file_free_security(struct file *file) 252 { 253 struct file_security_struct *fsec = file->f_security; 254 file->f_security = NULL; 255 kfree(fsec); 256 } 257 258 static int superblock_alloc_security(struct super_block *sb) 259 { 260 struct superblock_security_struct *sbsec; 261 262 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); 263 if (!sbsec) 264 return -ENOMEM; 265 266 mutex_init(&sbsec->lock); 267 INIT_LIST_HEAD(&sbsec->isec_head); 268 spin_lock_init(&sbsec->isec_lock); 269 sbsec->sb = sb; 270 sbsec->sid = SECINITSID_UNLABELED; 271 sbsec->def_sid = SECINITSID_FILE; 272 sbsec->mntpoint_sid = SECINITSID_UNLABELED; 273 sb->s_security = sbsec; 274 275 return 0; 276 } 277 278 static void superblock_free_security(struct super_block *sb) 279 { 280 struct superblock_security_struct *sbsec = sb->s_security; 281 sb->s_security = NULL; 282 kfree(sbsec); 283 } 284 285 /* The file system's label must be initialized prior to use. */ 286 287 static const char *labeling_behaviors[6] = { 288 "uses xattr", 289 "uses transition SIDs", 290 "uses task SIDs", 291 "uses genfs_contexts", 292 "not configured for labeling", 293 "uses mountpoint labeling", 294 }; 295 296 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); 297 298 static inline int inode_doinit(struct inode *inode) 299 { 300 return inode_doinit_with_dentry(inode, NULL); 301 } 302 303 enum { 304 Opt_error = -1, 305 Opt_context = 1, 306 Opt_fscontext = 2, 307 Opt_defcontext = 3, 308 Opt_rootcontext = 4, 309 Opt_labelsupport = 5, 310 }; 311 312 static const match_table_t tokens = { 313 {Opt_context, CONTEXT_STR "%s"}, 314 {Opt_fscontext, FSCONTEXT_STR "%s"}, 315 {Opt_defcontext, DEFCONTEXT_STR "%s"}, 316 {Opt_rootcontext, ROOTCONTEXT_STR "%s"}, 317 {Opt_labelsupport, LABELSUPP_STR}, 318 {Opt_error, NULL}, 319 }; 320 321 #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" 322 323 static int may_context_mount_sb_relabel(u32 sid, 324 struct superblock_security_struct *sbsec, 325 const struct cred *cred) 326 { 327 const struct task_security_struct *tsec = cred->security; 328 int rc; 329 330 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, 331 FILESYSTEM__RELABELFROM, NULL); 332 if (rc) 333 return rc; 334 335 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM, 336 FILESYSTEM__RELABELTO, NULL); 337 return rc; 338 } 339 340 static int may_context_mount_inode_relabel(u32 sid, 341 struct superblock_security_struct *sbsec, 342 const struct cred *cred) 343 { 344 const struct task_security_struct *tsec = cred->security; 345 int rc; 346 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, 347 FILESYSTEM__RELABELFROM, NULL); 348 if (rc) 349 return rc; 350 351 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, 352 FILESYSTEM__ASSOCIATE, NULL); 353 return rc; 354 } 355 356 static int sb_finish_set_opts(struct super_block *sb) 357 { 358 struct superblock_security_struct *sbsec = sb->s_security; 359 struct dentry *root = sb->s_root; 360 struct inode *root_inode = root->d_inode; 361 int rc = 0; 362 363 if (sbsec->behavior == SECURITY_FS_USE_XATTR) { 364 /* Make sure that the xattr handler exists and that no 365 error other than -ENODATA is returned by getxattr on 366 the root directory. -ENODATA is ok, as this may be 367 the first boot of the SELinux kernel before we have 368 assigned xattr values to the filesystem. */ 369 if (!root_inode->i_op->getxattr) { 370 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no " 371 "xattr support\n", sb->s_id, sb->s_type->name); 372 rc = -EOPNOTSUPP; 373 goto out; 374 } 375 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0); 376 if (rc < 0 && rc != -ENODATA) { 377 if (rc == -EOPNOTSUPP) 378 printk(KERN_WARNING "SELinux: (dev %s, type " 379 "%s) has no security xattr handler\n", 380 sb->s_id, sb->s_type->name); 381 else 382 printk(KERN_WARNING "SELinux: (dev %s, type " 383 "%s) getxattr errno %d\n", sb->s_id, 384 sb->s_type->name, -rc); 385 goto out; 386 } 387 } 388 389 sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP); 390 391 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) 392 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n", 393 sb->s_id, sb->s_type->name); 394 else 395 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n", 396 sb->s_id, sb->s_type->name, 397 labeling_behaviors[sbsec->behavior-1]); 398 399 if (sbsec->behavior == SECURITY_FS_USE_GENFS || 400 sbsec->behavior == SECURITY_FS_USE_MNTPOINT || 401 sbsec->behavior == SECURITY_FS_USE_NONE || 402 sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) 403 sbsec->flags &= ~SE_SBLABELSUPP; 404 405 /* Special handling for sysfs. Is genfs but also has setxattr handler*/ 406 if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0) 407 sbsec->flags |= SE_SBLABELSUPP; 408 409 /* Initialize the root inode. */ 410 rc = inode_doinit_with_dentry(root_inode, root); 411 412 /* Initialize any other inodes associated with the superblock, e.g. 413 inodes created prior to initial policy load or inodes created 414 during get_sb by a pseudo filesystem that directly 415 populates itself. */ 416 spin_lock(&sbsec->isec_lock); 417 next_inode: 418 if (!list_empty(&sbsec->isec_head)) { 419 struct inode_security_struct *isec = 420 list_entry(sbsec->isec_head.next, 421 struct inode_security_struct, list); 422 struct inode *inode = isec->inode; 423 spin_unlock(&sbsec->isec_lock); 424 inode = igrab(inode); 425 if (inode) { 426 if (!IS_PRIVATE(inode)) 427 inode_doinit(inode); 428 iput(inode); 429 } 430 spin_lock(&sbsec->isec_lock); 431 list_del_init(&isec->list); 432 goto next_inode; 433 } 434 spin_unlock(&sbsec->isec_lock); 435 out: 436 return rc; 437 } 438 439 /* 440 * This function should allow an FS to ask what it's mount security 441 * options were so it can use those later for submounts, displaying 442 * mount options, or whatever. 443 */ 444 static int selinux_get_mnt_opts(const struct super_block *sb, 445 struct security_mnt_opts *opts) 446 { 447 int rc = 0, i; 448 struct superblock_security_struct *sbsec = sb->s_security; 449 char *context = NULL; 450 u32 len; 451 char tmp; 452 453 security_init_mnt_opts(opts); 454 455 if (!(sbsec->flags & SE_SBINITIALIZED)) 456 return -EINVAL; 457 458 if (!ss_initialized) 459 return -EINVAL; 460 461 tmp = sbsec->flags & SE_MNTMASK; 462 /* count the number of mount options for this sb */ 463 for (i = 0; i < 8; i++) { 464 if (tmp & 0x01) 465 opts->num_mnt_opts++; 466 tmp >>= 1; 467 } 468 /* Check if the Label support flag is set */ 469 if (sbsec->flags & SE_SBLABELSUPP) 470 opts->num_mnt_opts++; 471 472 opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC); 473 if (!opts->mnt_opts) { 474 rc = -ENOMEM; 475 goto out_free; 476 } 477 478 opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC); 479 if (!opts->mnt_opts_flags) { 480 rc = -ENOMEM; 481 goto out_free; 482 } 483 484 i = 0; 485 if (sbsec->flags & FSCONTEXT_MNT) { 486 rc = security_sid_to_context(sbsec->sid, &context, &len); 487 if (rc) 488 goto out_free; 489 opts->mnt_opts[i] = context; 490 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT; 491 } 492 if (sbsec->flags & CONTEXT_MNT) { 493 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len); 494 if (rc) 495 goto out_free; 496 opts->mnt_opts[i] = context; 497 opts->mnt_opts_flags[i++] = CONTEXT_MNT; 498 } 499 if (sbsec->flags & DEFCONTEXT_MNT) { 500 rc = security_sid_to_context(sbsec->def_sid, &context, &len); 501 if (rc) 502 goto out_free; 503 opts->mnt_opts[i] = context; 504 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT; 505 } 506 if (sbsec->flags & ROOTCONTEXT_MNT) { 507 struct inode *root = sbsec->sb->s_root->d_inode; 508 struct inode_security_struct *isec = root->i_security; 509 510 rc = security_sid_to_context(isec->sid, &context, &len); 511 if (rc) 512 goto out_free; 513 opts->mnt_opts[i] = context; 514 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT; 515 } 516 if (sbsec->flags & SE_SBLABELSUPP) { 517 opts->mnt_opts[i] = NULL; 518 opts->mnt_opts_flags[i++] = SE_SBLABELSUPP; 519 } 520 521 BUG_ON(i != opts->num_mnt_opts); 522 523 return 0; 524 525 out_free: 526 security_free_mnt_opts(opts); 527 return rc; 528 } 529 530 static int bad_option(struct superblock_security_struct *sbsec, char flag, 531 u32 old_sid, u32 new_sid) 532 { 533 char mnt_flags = sbsec->flags & SE_MNTMASK; 534 535 /* check if the old mount command had the same options */ 536 if (sbsec->flags & SE_SBINITIALIZED) 537 if (!(sbsec->flags & flag) || 538 (old_sid != new_sid)) 539 return 1; 540 541 /* check if we were passed the same options twice, 542 * aka someone passed context=a,context=b 543 */ 544 if (!(sbsec->flags & SE_SBINITIALIZED)) 545 if (mnt_flags & flag) 546 return 1; 547 return 0; 548 } 549 550 /* 551 * Allow filesystems with binary mount data to explicitly set mount point 552 * labeling information. 553 */ 554 static int selinux_set_mnt_opts(struct super_block *sb, 555 struct security_mnt_opts *opts) 556 { 557 const struct cred *cred = current_cred(); 558 int rc = 0, i; 559 struct superblock_security_struct *sbsec = sb->s_security; 560 const char *name = sb->s_type->name; 561 struct inode *inode = sbsec->sb->s_root->d_inode; 562 struct inode_security_struct *root_isec = inode->i_security; 563 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; 564 u32 defcontext_sid = 0; 565 char **mount_options = opts->mnt_opts; 566 int *flags = opts->mnt_opts_flags; 567 int num_opts = opts->num_mnt_opts; 568 569 mutex_lock(&sbsec->lock); 570 571 if (!ss_initialized) { 572 if (!num_opts) { 573 /* Defer initialization until selinux_complete_init, 574 after the initial policy is loaded and the security 575 server is ready to handle calls. */ 576 goto out; 577 } 578 rc = -EINVAL; 579 printk(KERN_WARNING "SELinux: Unable to set superblock options " 580 "before the security server is initialized\n"); 581 goto out; 582 } 583 584 /* 585 * Binary mount data FS will come through this function twice. Once 586 * from an explicit call and once from the generic calls from the vfs. 587 * Since the generic VFS calls will not contain any security mount data 588 * we need to skip the double mount verification. 589 * 590 * This does open a hole in which we will not notice if the first 591 * mount using this sb set explict options and a second mount using 592 * this sb does not set any security options. (The first options 593 * will be used for both mounts) 594 */ 595 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) 596 && (num_opts == 0)) 597 goto out; 598 599 /* 600 * parse the mount options, check if they are valid sids. 601 * also check if someone is trying to mount the same sb more 602 * than once with different security options. 603 */ 604 for (i = 0; i < num_opts; i++) { 605 u32 sid; 606 607 if (flags[i] == SE_SBLABELSUPP) 608 continue; 609 rc = security_context_to_sid(mount_options[i], 610 strlen(mount_options[i]), &sid); 611 if (rc) { 612 printk(KERN_WARNING "SELinux: security_context_to_sid" 613 "(%s) failed for (dev %s, type %s) errno=%d\n", 614 mount_options[i], sb->s_id, name, rc); 615 goto out; 616 } 617 switch (flags[i]) { 618 case FSCONTEXT_MNT: 619 fscontext_sid = sid; 620 621 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, 622 fscontext_sid)) 623 goto out_double_mount; 624 625 sbsec->flags |= FSCONTEXT_MNT; 626 break; 627 case CONTEXT_MNT: 628 context_sid = sid; 629 630 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, 631 context_sid)) 632 goto out_double_mount; 633 634 sbsec->flags |= CONTEXT_MNT; 635 break; 636 case ROOTCONTEXT_MNT: 637 rootcontext_sid = sid; 638 639 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, 640 rootcontext_sid)) 641 goto out_double_mount; 642 643 sbsec->flags |= ROOTCONTEXT_MNT; 644 645 break; 646 case DEFCONTEXT_MNT: 647 defcontext_sid = sid; 648 649 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, 650 defcontext_sid)) 651 goto out_double_mount; 652 653 sbsec->flags |= DEFCONTEXT_MNT; 654 655 break; 656 default: 657 rc = -EINVAL; 658 goto out; 659 } 660 } 661 662 if (sbsec->flags & SE_SBINITIALIZED) { 663 /* previously mounted with options, but not on this attempt? */ 664 if ((sbsec->flags & SE_MNTMASK) && !num_opts) 665 goto out_double_mount; 666 rc = 0; 667 goto out; 668 } 669 670 if (strcmp(sb->s_type->name, "proc") == 0) 671 sbsec->flags |= SE_SBPROC; 672 673 /* Determine the labeling behavior to use for this filesystem type. */ 674 rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid); 675 if (rc) { 676 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n", 677 __func__, sb->s_type->name, rc); 678 goto out; 679 } 680 681 /* sets the context of the superblock for the fs being mounted. */ 682 if (fscontext_sid) { 683 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); 684 if (rc) 685 goto out; 686 687 sbsec->sid = fscontext_sid; 688 } 689 690 /* 691 * Switch to using mount point labeling behavior. 692 * sets the label used on all file below the mountpoint, and will set 693 * the superblock context if not already set. 694 */ 695 if (context_sid) { 696 if (!fscontext_sid) { 697 rc = may_context_mount_sb_relabel(context_sid, sbsec, 698 cred); 699 if (rc) 700 goto out; 701 sbsec->sid = context_sid; 702 } else { 703 rc = may_context_mount_inode_relabel(context_sid, sbsec, 704 cred); 705 if (rc) 706 goto out; 707 } 708 if (!rootcontext_sid) 709 rootcontext_sid = context_sid; 710 711 sbsec->mntpoint_sid = context_sid; 712 sbsec->behavior = SECURITY_FS_USE_MNTPOINT; 713 } 714 715 if (rootcontext_sid) { 716 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, 717 cred); 718 if (rc) 719 goto out; 720 721 root_isec->sid = rootcontext_sid; 722 root_isec->initialized = 1; 723 } 724 725 if (defcontext_sid) { 726 if (sbsec->behavior != SECURITY_FS_USE_XATTR) { 727 rc = -EINVAL; 728 printk(KERN_WARNING "SELinux: defcontext option is " 729 "invalid for this filesystem type\n"); 730 goto out; 731 } 732 733 if (defcontext_sid != sbsec->def_sid) { 734 rc = may_context_mount_inode_relabel(defcontext_sid, 735 sbsec, cred); 736 if (rc) 737 goto out; 738 } 739 740 sbsec->def_sid = defcontext_sid; 741 } 742 743 rc = sb_finish_set_opts(sb); 744 out: 745 mutex_unlock(&sbsec->lock); 746 return rc; 747 out_double_mount: 748 rc = -EINVAL; 749 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different " 750 "security settings for (dev %s, type %s)\n", sb->s_id, name); 751 goto out; 752 } 753 754 static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb, 755 struct super_block *newsb) 756 { 757 const struct superblock_security_struct *oldsbsec = oldsb->s_security; 758 struct superblock_security_struct *newsbsec = newsb->s_security; 759 760 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); 761 int set_context = (oldsbsec->flags & CONTEXT_MNT); 762 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT); 763 764 /* 765 * if the parent was able to be mounted it clearly had no special lsm 766 * mount options. thus we can safely deal with this superblock later 767 */ 768 if (!ss_initialized) 769 return; 770 771 /* how can we clone if the old one wasn't set up?? */ 772 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED)); 773 774 /* if fs is reusing a sb, just let its options stand... */ 775 if (newsbsec->flags & SE_SBINITIALIZED) 776 return; 777 778 mutex_lock(&newsbsec->lock); 779 780 newsbsec->flags = oldsbsec->flags; 781 782 newsbsec->sid = oldsbsec->sid; 783 newsbsec->def_sid = oldsbsec->def_sid; 784 newsbsec->behavior = oldsbsec->behavior; 785 786 if (set_context) { 787 u32 sid = oldsbsec->mntpoint_sid; 788 789 if (!set_fscontext) 790 newsbsec->sid = sid; 791 if (!set_rootcontext) { 792 struct inode *newinode = newsb->s_root->d_inode; 793 struct inode_security_struct *newisec = newinode->i_security; 794 newisec->sid = sid; 795 } 796 newsbsec->mntpoint_sid = sid; 797 } 798 if (set_rootcontext) { 799 const struct inode *oldinode = oldsb->s_root->d_inode; 800 const struct inode_security_struct *oldisec = oldinode->i_security; 801 struct inode *newinode = newsb->s_root->d_inode; 802 struct inode_security_struct *newisec = newinode->i_security; 803 804 newisec->sid = oldisec->sid; 805 } 806 807 sb_finish_set_opts(newsb); 808 mutex_unlock(&newsbsec->lock); 809 } 810 811 static int selinux_parse_opts_str(char *options, 812 struct security_mnt_opts *opts) 813 { 814 char *p; 815 char *context = NULL, *defcontext = NULL; 816 char *fscontext = NULL, *rootcontext = NULL; 817 int rc, num_mnt_opts = 0; 818 819 opts->num_mnt_opts = 0; 820 821 /* Standard string-based options. */ 822 while ((p = strsep(&options, "|")) != NULL) { 823 int token; 824 substring_t args[MAX_OPT_ARGS]; 825 826 if (!*p) 827 continue; 828 829 token = match_token(p, tokens, args); 830 831 switch (token) { 832 case Opt_context: 833 if (context || defcontext) { 834 rc = -EINVAL; 835 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 836 goto out_err; 837 } 838 context = match_strdup(&args[0]); 839 if (!context) { 840 rc = -ENOMEM; 841 goto out_err; 842 } 843 break; 844 845 case Opt_fscontext: 846 if (fscontext) { 847 rc = -EINVAL; 848 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 849 goto out_err; 850 } 851 fscontext = match_strdup(&args[0]); 852 if (!fscontext) { 853 rc = -ENOMEM; 854 goto out_err; 855 } 856 break; 857 858 case Opt_rootcontext: 859 if (rootcontext) { 860 rc = -EINVAL; 861 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 862 goto out_err; 863 } 864 rootcontext = match_strdup(&args[0]); 865 if (!rootcontext) { 866 rc = -ENOMEM; 867 goto out_err; 868 } 869 break; 870 871 case Opt_defcontext: 872 if (context || defcontext) { 873 rc = -EINVAL; 874 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 875 goto out_err; 876 } 877 defcontext = match_strdup(&args[0]); 878 if (!defcontext) { 879 rc = -ENOMEM; 880 goto out_err; 881 } 882 break; 883 case Opt_labelsupport: 884 break; 885 default: 886 rc = -EINVAL; 887 printk(KERN_WARNING "SELinux: unknown mount option\n"); 888 goto out_err; 889 890 } 891 } 892 893 rc = -ENOMEM; 894 opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC); 895 if (!opts->mnt_opts) 896 goto out_err; 897 898 opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC); 899 if (!opts->mnt_opts_flags) { 900 kfree(opts->mnt_opts); 901 goto out_err; 902 } 903 904 if (fscontext) { 905 opts->mnt_opts[num_mnt_opts] = fscontext; 906 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT; 907 } 908 if (context) { 909 opts->mnt_opts[num_mnt_opts] = context; 910 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT; 911 } 912 if (rootcontext) { 913 opts->mnt_opts[num_mnt_opts] = rootcontext; 914 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT; 915 } 916 if (defcontext) { 917 opts->mnt_opts[num_mnt_opts] = defcontext; 918 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT; 919 } 920 921 opts->num_mnt_opts = num_mnt_opts; 922 return 0; 923 924 out_err: 925 kfree(context); 926 kfree(defcontext); 927 kfree(fscontext); 928 kfree(rootcontext); 929 return rc; 930 } 931 /* 932 * string mount options parsing and call set the sbsec 933 */ 934 static int superblock_doinit(struct super_block *sb, void *data) 935 { 936 int rc = 0; 937 char *options = data; 938 struct security_mnt_opts opts; 939 940 security_init_mnt_opts(&opts); 941 942 if (!data) 943 goto out; 944 945 BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA); 946 947 rc = selinux_parse_opts_str(options, &opts); 948 if (rc) 949 goto out_err; 950 951 out: 952 rc = selinux_set_mnt_opts(sb, &opts); 953 954 out_err: 955 security_free_mnt_opts(&opts); 956 return rc; 957 } 958 959 static void selinux_write_opts(struct seq_file *m, 960 struct security_mnt_opts *opts) 961 { 962 int i; 963 char *prefix; 964 965 for (i = 0; i < opts->num_mnt_opts; i++) { 966 char *has_comma; 967 968 if (opts->mnt_opts[i]) 969 has_comma = strchr(opts->mnt_opts[i], ','); 970 else 971 has_comma = NULL; 972 973 switch (opts->mnt_opts_flags[i]) { 974 case CONTEXT_MNT: 975 prefix = CONTEXT_STR; 976 break; 977 case FSCONTEXT_MNT: 978 prefix = FSCONTEXT_STR; 979 break; 980 case ROOTCONTEXT_MNT: 981 prefix = ROOTCONTEXT_STR; 982 break; 983 case DEFCONTEXT_MNT: 984 prefix = DEFCONTEXT_STR; 985 break; 986 case SE_SBLABELSUPP: 987 seq_putc(m, ','); 988 seq_puts(m, LABELSUPP_STR); 989 continue; 990 default: 991 BUG(); 992 return; 993 }; 994 /* we need a comma before each option */ 995 seq_putc(m, ','); 996 seq_puts(m, prefix); 997 if (has_comma) 998 seq_putc(m, '\"'); 999 seq_puts(m, opts->mnt_opts[i]); 1000 if (has_comma) 1001 seq_putc(m, '\"'); 1002 } 1003 } 1004 1005 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) 1006 { 1007 struct security_mnt_opts opts; 1008 int rc; 1009 1010 rc = selinux_get_mnt_opts(sb, &opts); 1011 if (rc) { 1012 /* before policy load we may get EINVAL, don't show anything */ 1013 if (rc == -EINVAL) 1014 rc = 0; 1015 return rc; 1016 } 1017 1018 selinux_write_opts(m, &opts); 1019 1020 security_free_mnt_opts(&opts); 1021 1022 return rc; 1023 } 1024 1025 static inline u16 inode_mode_to_security_class(umode_t mode) 1026 { 1027 switch (mode & S_IFMT) { 1028 case S_IFSOCK: 1029 return SECCLASS_SOCK_FILE; 1030 case S_IFLNK: 1031 return SECCLASS_LNK_FILE; 1032 case S_IFREG: 1033 return SECCLASS_FILE; 1034 case S_IFBLK: 1035 return SECCLASS_BLK_FILE; 1036 case S_IFDIR: 1037 return SECCLASS_DIR; 1038 case S_IFCHR: 1039 return SECCLASS_CHR_FILE; 1040 case S_IFIFO: 1041 return SECCLASS_FIFO_FILE; 1042 1043 } 1044 1045 return SECCLASS_FILE; 1046 } 1047 1048 static inline int default_protocol_stream(int protocol) 1049 { 1050 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP); 1051 } 1052 1053 static inline int default_protocol_dgram(int protocol) 1054 { 1055 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP); 1056 } 1057 1058 static inline u16 socket_type_to_security_class(int family, int type, int protocol) 1059 { 1060 switch (family) { 1061 case PF_UNIX: 1062 switch (type) { 1063 case SOCK_STREAM: 1064 case SOCK_SEQPACKET: 1065 return SECCLASS_UNIX_STREAM_SOCKET; 1066 case SOCK_DGRAM: 1067 return SECCLASS_UNIX_DGRAM_SOCKET; 1068 } 1069 break; 1070 case PF_INET: 1071 case PF_INET6: 1072 switch (type) { 1073 case SOCK_STREAM: 1074 if (default_protocol_stream(protocol)) 1075 return SECCLASS_TCP_SOCKET; 1076 else 1077 return SECCLASS_RAWIP_SOCKET; 1078 case SOCK_DGRAM: 1079 if (default_protocol_dgram(protocol)) 1080 return SECCLASS_UDP_SOCKET; 1081 else 1082 return SECCLASS_RAWIP_SOCKET; 1083 case SOCK_DCCP: 1084 return SECCLASS_DCCP_SOCKET; 1085 default: 1086 return SECCLASS_RAWIP_SOCKET; 1087 } 1088 break; 1089 case PF_NETLINK: 1090 switch (protocol) { 1091 case NETLINK_ROUTE: 1092 return SECCLASS_NETLINK_ROUTE_SOCKET; 1093 case NETLINK_FIREWALL: 1094 return SECCLASS_NETLINK_FIREWALL_SOCKET; 1095 case NETLINK_SOCK_DIAG: 1096 return SECCLASS_NETLINK_TCPDIAG_SOCKET; 1097 case NETLINK_NFLOG: 1098 return SECCLASS_NETLINK_NFLOG_SOCKET; 1099 case NETLINK_XFRM: 1100 return SECCLASS_NETLINK_XFRM_SOCKET; 1101 case NETLINK_SELINUX: 1102 return SECCLASS_NETLINK_SELINUX_SOCKET; 1103 case NETLINK_AUDIT: 1104 return SECCLASS_NETLINK_AUDIT_SOCKET; 1105 case NETLINK_IP6_FW: 1106 return SECCLASS_NETLINK_IP6FW_SOCKET; 1107 case NETLINK_DNRTMSG: 1108 return SECCLASS_NETLINK_DNRT_SOCKET; 1109 case NETLINK_KOBJECT_UEVENT: 1110 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; 1111 default: 1112 return SECCLASS_NETLINK_SOCKET; 1113 } 1114 case PF_PACKET: 1115 return SECCLASS_PACKET_SOCKET; 1116 case PF_KEY: 1117 return SECCLASS_KEY_SOCKET; 1118 case PF_APPLETALK: 1119 return SECCLASS_APPLETALK_SOCKET; 1120 } 1121 1122 return SECCLASS_SOCKET; 1123 } 1124 1125 #ifdef CONFIG_PROC_FS 1126 static int selinux_proc_get_sid(struct dentry *dentry, 1127 u16 tclass, 1128 u32 *sid) 1129 { 1130 int rc; 1131 char *buffer, *path; 1132 1133 buffer = (char *)__get_free_page(GFP_KERNEL); 1134 if (!buffer) 1135 return -ENOMEM; 1136 1137 path = dentry_path_raw(dentry, buffer, PAGE_SIZE); 1138 if (IS_ERR(path)) 1139 rc = PTR_ERR(path); 1140 else { 1141 /* each process gets a /proc/PID/ entry. Strip off the 1142 * PID part to get a valid selinux labeling. 1143 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */ 1144 while (path[1] >= '0' && path[1] <= '9') { 1145 path[1] = '/'; 1146 path++; 1147 } 1148 rc = security_genfs_sid("proc", path, tclass, sid); 1149 } 1150 free_page((unsigned long)buffer); 1151 return rc; 1152 } 1153 #else 1154 static int selinux_proc_get_sid(struct dentry *dentry, 1155 u16 tclass, 1156 u32 *sid) 1157 { 1158 return -EINVAL; 1159 } 1160 #endif 1161 1162 /* The inode's security attributes must be initialized before first use. */ 1163 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) 1164 { 1165 struct superblock_security_struct *sbsec = NULL; 1166 struct inode_security_struct *isec = inode->i_security; 1167 u32 sid; 1168 struct dentry *dentry; 1169 #define INITCONTEXTLEN 255 1170 char *context = NULL; 1171 unsigned len = 0; 1172 int rc = 0; 1173 1174 if (isec->initialized) 1175 goto out; 1176 1177 mutex_lock(&isec->lock); 1178 if (isec->initialized) 1179 goto out_unlock; 1180 1181 sbsec = inode->i_sb->s_security; 1182 if (!(sbsec->flags & SE_SBINITIALIZED)) { 1183 /* Defer initialization until selinux_complete_init, 1184 after the initial policy is loaded and the security 1185 server is ready to handle calls. */ 1186 spin_lock(&sbsec->isec_lock); 1187 if (list_empty(&isec->list)) 1188 list_add(&isec->list, &sbsec->isec_head); 1189 spin_unlock(&sbsec->isec_lock); 1190 goto out_unlock; 1191 } 1192 1193 switch (sbsec->behavior) { 1194 case SECURITY_FS_USE_XATTR: 1195 if (!inode->i_op->getxattr) { 1196 isec->sid = sbsec->def_sid; 1197 break; 1198 } 1199 1200 /* Need a dentry, since the xattr API requires one. 1201 Life would be simpler if we could just pass the inode. */ 1202 if (opt_dentry) { 1203 /* Called from d_instantiate or d_splice_alias. */ 1204 dentry = dget(opt_dentry); 1205 } else { 1206 /* Called from selinux_complete_init, try to find a dentry. */ 1207 dentry = d_find_alias(inode); 1208 } 1209 if (!dentry) { 1210 /* 1211 * this is can be hit on boot when a file is accessed 1212 * before the policy is loaded. When we load policy we 1213 * may find inodes that have no dentry on the 1214 * sbsec->isec_head list. No reason to complain as these 1215 * will get fixed up the next time we go through 1216 * inode_doinit with a dentry, before these inodes could 1217 * be used again by userspace. 1218 */ 1219 goto out_unlock; 1220 } 1221 1222 len = INITCONTEXTLEN; 1223 context = kmalloc(len+1, GFP_NOFS); 1224 if (!context) { 1225 rc = -ENOMEM; 1226 dput(dentry); 1227 goto out_unlock; 1228 } 1229 context[len] = '\0'; 1230 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, 1231 context, len); 1232 if (rc == -ERANGE) { 1233 kfree(context); 1234 1235 /* Need a larger buffer. Query for the right size. */ 1236 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, 1237 NULL, 0); 1238 if (rc < 0) { 1239 dput(dentry); 1240 goto out_unlock; 1241 } 1242 len = rc; 1243 context = kmalloc(len+1, GFP_NOFS); 1244 if (!context) { 1245 rc = -ENOMEM; 1246 dput(dentry); 1247 goto out_unlock; 1248 } 1249 context[len] = '\0'; 1250 rc = inode->i_op->getxattr(dentry, 1251 XATTR_NAME_SELINUX, 1252 context, len); 1253 } 1254 dput(dentry); 1255 if (rc < 0) { 1256 if (rc != -ENODATA) { 1257 printk(KERN_WARNING "SELinux: %s: getxattr returned " 1258 "%d for dev=%s ino=%ld\n", __func__, 1259 -rc, inode->i_sb->s_id, inode->i_ino); 1260 kfree(context); 1261 goto out_unlock; 1262 } 1263 /* Map ENODATA to the default file SID */ 1264 sid = sbsec->def_sid; 1265 rc = 0; 1266 } else { 1267 rc = security_context_to_sid_default(context, rc, &sid, 1268 sbsec->def_sid, 1269 GFP_NOFS); 1270 if (rc) { 1271 char *dev = inode->i_sb->s_id; 1272 unsigned long ino = inode->i_ino; 1273 1274 if (rc == -EINVAL) { 1275 if (printk_ratelimit()) 1276 printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid " 1277 "context=%s. This indicates you may need to relabel the inode or the " 1278 "filesystem in question.\n", ino, dev, context); 1279 } else { 1280 printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) " 1281 "returned %d for dev=%s ino=%ld\n", 1282 __func__, context, -rc, dev, ino); 1283 } 1284 kfree(context); 1285 /* Leave with the unlabeled SID */ 1286 rc = 0; 1287 break; 1288 } 1289 } 1290 kfree(context); 1291 isec->sid = sid; 1292 break; 1293 case SECURITY_FS_USE_TASK: 1294 isec->sid = isec->task_sid; 1295 break; 1296 case SECURITY_FS_USE_TRANS: 1297 /* Default to the fs SID. */ 1298 isec->sid = sbsec->sid; 1299 1300 /* Try to obtain a transition SID. */ 1301 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1302 rc = security_transition_sid(isec->task_sid, sbsec->sid, 1303 isec->sclass, NULL, &sid); 1304 if (rc) 1305 goto out_unlock; 1306 isec->sid = sid; 1307 break; 1308 case SECURITY_FS_USE_MNTPOINT: 1309 isec->sid = sbsec->mntpoint_sid; 1310 break; 1311 default: 1312 /* Default to the fs superblock SID. */ 1313 isec->sid = sbsec->sid; 1314 1315 if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) { 1316 if (opt_dentry) { 1317 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1318 rc = selinux_proc_get_sid(opt_dentry, 1319 isec->sclass, 1320 &sid); 1321 if (rc) 1322 goto out_unlock; 1323 isec->sid = sid; 1324 } 1325 } 1326 break; 1327 } 1328 1329 isec->initialized = 1; 1330 1331 out_unlock: 1332 mutex_unlock(&isec->lock); 1333 out: 1334 if (isec->sclass == SECCLASS_FILE) 1335 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1336 return rc; 1337 } 1338 1339 /* Convert a Linux signal to an access vector. */ 1340 static inline u32 signal_to_av(int sig) 1341 { 1342 u32 perm = 0; 1343 1344 switch (sig) { 1345 case SIGCHLD: 1346 /* Commonly granted from child to parent. */ 1347 perm = PROCESS__SIGCHLD; 1348 break; 1349 case SIGKILL: 1350 /* Cannot be caught or ignored */ 1351 perm = PROCESS__SIGKILL; 1352 break; 1353 case SIGSTOP: 1354 /* Cannot be caught or ignored */ 1355 perm = PROCESS__SIGSTOP; 1356 break; 1357 default: 1358 /* All other signals. */ 1359 perm = PROCESS__SIGNAL; 1360 break; 1361 } 1362 1363 return perm; 1364 } 1365 1366 /* 1367 * Check permission between a pair of credentials 1368 * fork check, ptrace check, etc. 1369 */ 1370 static int cred_has_perm(const struct cred *actor, 1371 const struct cred *target, 1372 u32 perms) 1373 { 1374 u32 asid = cred_sid(actor), tsid = cred_sid(target); 1375 1376 return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL); 1377 } 1378 1379 /* 1380 * Check permission between a pair of tasks, e.g. signal checks, 1381 * fork check, ptrace check, etc. 1382 * tsk1 is the actor and tsk2 is the target 1383 * - this uses the default subjective creds of tsk1 1384 */ 1385 static int task_has_perm(const struct task_struct *tsk1, 1386 const struct task_struct *tsk2, 1387 u32 perms) 1388 { 1389 const struct task_security_struct *__tsec1, *__tsec2; 1390 u32 sid1, sid2; 1391 1392 rcu_read_lock(); 1393 __tsec1 = __task_cred(tsk1)->security; sid1 = __tsec1->sid; 1394 __tsec2 = __task_cred(tsk2)->security; sid2 = __tsec2->sid; 1395 rcu_read_unlock(); 1396 return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL); 1397 } 1398 1399 /* 1400 * Check permission between current and another task, e.g. signal checks, 1401 * fork check, ptrace check, etc. 1402 * current is the actor and tsk2 is the target 1403 * - this uses current's subjective creds 1404 */ 1405 static int current_has_perm(const struct task_struct *tsk, 1406 u32 perms) 1407 { 1408 u32 sid, tsid; 1409 1410 sid = current_sid(); 1411 tsid = task_sid(tsk); 1412 return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL); 1413 } 1414 1415 #if CAP_LAST_CAP > 63 1416 #error Fix SELinux to handle capabilities > 63. 1417 #endif 1418 1419 /* Check whether a task is allowed to use a capability. */ 1420 static int cred_has_capability(const struct cred *cred, 1421 int cap, int audit) 1422 { 1423 struct common_audit_data ad; 1424 struct av_decision avd; 1425 u16 sclass; 1426 u32 sid = cred_sid(cred); 1427 u32 av = CAP_TO_MASK(cap); 1428 int rc; 1429 1430 COMMON_AUDIT_DATA_INIT(&ad, CAP); 1431 ad.tsk = current; 1432 ad.u.cap = cap; 1433 1434 switch (CAP_TO_INDEX(cap)) { 1435 case 0: 1436 sclass = SECCLASS_CAPABILITY; 1437 break; 1438 case 1: 1439 sclass = SECCLASS_CAPABILITY2; 1440 break; 1441 default: 1442 printk(KERN_ERR 1443 "SELinux: out of range capability %d\n", cap); 1444 BUG(); 1445 return -EINVAL; 1446 } 1447 1448 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd); 1449 if (audit == SECURITY_CAP_AUDIT) { 1450 int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0); 1451 if (rc2) 1452 return rc2; 1453 } 1454 return rc; 1455 } 1456 1457 /* Check whether a task is allowed to use a system operation. */ 1458 static int task_has_system(struct task_struct *tsk, 1459 u32 perms) 1460 { 1461 u32 sid = task_sid(tsk); 1462 1463 return avc_has_perm(sid, SECINITSID_KERNEL, 1464 SECCLASS_SYSTEM, perms, NULL); 1465 } 1466 1467 /* Check whether a task has a particular permission to an inode. 1468 The 'adp' parameter is optional and allows other audit 1469 data to be passed (e.g. the dentry). */ 1470 static int inode_has_perm(const struct cred *cred, 1471 struct inode *inode, 1472 u32 perms, 1473 struct common_audit_data *adp, 1474 unsigned flags) 1475 { 1476 struct inode_security_struct *isec; 1477 u32 sid; 1478 1479 validate_creds(cred); 1480 1481 if (unlikely(IS_PRIVATE(inode))) 1482 return 0; 1483 1484 sid = cred_sid(cred); 1485 isec = inode->i_security; 1486 1487 return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags); 1488 } 1489 1490 static int inode_has_perm_noadp(const struct cred *cred, 1491 struct inode *inode, 1492 u32 perms, 1493 unsigned flags) 1494 { 1495 struct common_audit_data ad; 1496 1497 COMMON_AUDIT_DATA_INIT(&ad, INODE); 1498 ad.u.inode = inode; 1499 return inode_has_perm(cred, inode, perms, &ad, flags); 1500 } 1501 1502 /* Same as inode_has_perm, but pass explicit audit data containing 1503 the dentry to help the auditing code to more easily generate the 1504 pathname if needed. */ 1505 static inline int dentry_has_perm(const struct cred *cred, 1506 struct dentry *dentry, 1507 u32 av) 1508 { 1509 struct inode *inode = dentry->d_inode; 1510 struct common_audit_data ad; 1511 1512 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 1513 ad.u.dentry = dentry; 1514 return inode_has_perm(cred, inode, av, &ad, 0); 1515 } 1516 1517 /* Same as inode_has_perm, but pass explicit audit data containing 1518 the path to help the auditing code to more easily generate the 1519 pathname if needed. */ 1520 static inline int path_has_perm(const struct cred *cred, 1521 struct path *path, 1522 u32 av) 1523 { 1524 struct inode *inode = path->dentry->d_inode; 1525 struct common_audit_data ad; 1526 1527 COMMON_AUDIT_DATA_INIT(&ad, PATH); 1528 ad.u.path = *path; 1529 return inode_has_perm(cred, inode, av, &ad, 0); 1530 } 1531 1532 /* Check whether a task can use an open file descriptor to 1533 access an inode in a given way. Check access to the 1534 descriptor itself, and then use dentry_has_perm to 1535 check a particular permission to the file. 1536 Access to the descriptor is implicitly granted if it 1537 has the same SID as the process. If av is zero, then 1538 access to the file is not checked, e.g. for cases 1539 where only the descriptor is affected like seek. */ 1540 static int file_has_perm(const struct cred *cred, 1541 struct file *file, 1542 u32 av) 1543 { 1544 struct file_security_struct *fsec = file->f_security; 1545 struct inode *inode = file->f_path.dentry->d_inode; 1546 struct common_audit_data ad; 1547 u32 sid = cred_sid(cred); 1548 int rc; 1549 1550 COMMON_AUDIT_DATA_INIT(&ad, PATH); 1551 ad.u.path = file->f_path; 1552 1553 if (sid != fsec->sid) { 1554 rc = avc_has_perm(sid, fsec->sid, 1555 SECCLASS_FD, 1556 FD__USE, 1557 &ad); 1558 if (rc) 1559 goto out; 1560 } 1561 1562 /* av is zero if only checking access to the descriptor. */ 1563 rc = 0; 1564 if (av) 1565 rc = inode_has_perm(cred, inode, av, &ad, 0); 1566 1567 out: 1568 return rc; 1569 } 1570 1571 /* Check whether a task can create a file. */ 1572 static int may_create(struct inode *dir, 1573 struct dentry *dentry, 1574 u16 tclass) 1575 { 1576 const struct task_security_struct *tsec = current_security(); 1577 struct inode_security_struct *dsec; 1578 struct superblock_security_struct *sbsec; 1579 u32 sid, newsid; 1580 struct common_audit_data ad; 1581 int rc; 1582 1583 dsec = dir->i_security; 1584 sbsec = dir->i_sb->s_security; 1585 1586 sid = tsec->sid; 1587 newsid = tsec->create_sid; 1588 1589 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 1590 ad.u.dentry = dentry; 1591 1592 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, 1593 DIR__ADD_NAME | DIR__SEARCH, 1594 &ad); 1595 if (rc) 1596 return rc; 1597 1598 if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) { 1599 rc = security_transition_sid(sid, dsec->sid, tclass, 1600 &dentry->d_name, &newsid); 1601 if (rc) 1602 return rc; 1603 } 1604 1605 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad); 1606 if (rc) 1607 return rc; 1608 1609 return avc_has_perm(newsid, sbsec->sid, 1610 SECCLASS_FILESYSTEM, 1611 FILESYSTEM__ASSOCIATE, &ad); 1612 } 1613 1614 /* Check whether a task can create a key. */ 1615 static int may_create_key(u32 ksid, 1616 struct task_struct *ctx) 1617 { 1618 u32 sid = task_sid(ctx); 1619 1620 return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL); 1621 } 1622 1623 #define MAY_LINK 0 1624 #define MAY_UNLINK 1 1625 #define MAY_RMDIR 2 1626 1627 /* Check whether a task can link, unlink, or rmdir a file/directory. */ 1628 static int may_link(struct inode *dir, 1629 struct dentry *dentry, 1630 int kind) 1631 1632 { 1633 struct inode_security_struct *dsec, *isec; 1634 struct common_audit_data ad; 1635 u32 sid = current_sid(); 1636 u32 av; 1637 int rc; 1638 1639 dsec = dir->i_security; 1640 isec = dentry->d_inode->i_security; 1641 1642 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 1643 ad.u.dentry = dentry; 1644 1645 av = DIR__SEARCH; 1646 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); 1647 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad); 1648 if (rc) 1649 return rc; 1650 1651 switch (kind) { 1652 case MAY_LINK: 1653 av = FILE__LINK; 1654 break; 1655 case MAY_UNLINK: 1656 av = FILE__UNLINK; 1657 break; 1658 case MAY_RMDIR: 1659 av = DIR__RMDIR; 1660 break; 1661 default: 1662 printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n", 1663 __func__, kind); 1664 return 0; 1665 } 1666 1667 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad); 1668 return rc; 1669 } 1670 1671 static inline int may_rename(struct inode *old_dir, 1672 struct dentry *old_dentry, 1673 struct inode *new_dir, 1674 struct dentry *new_dentry) 1675 { 1676 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; 1677 struct common_audit_data ad; 1678 u32 sid = current_sid(); 1679 u32 av; 1680 int old_is_dir, new_is_dir; 1681 int rc; 1682 1683 old_dsec = old_dir->i_security; 1684 old_isec = old_dentry->d_inode->i_security; 1685 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode); 1686 new_dsec = new_dir->i_security; 1687 1688 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 1689 1690 ad.u.dentry = old_dentry; 1691 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR, 1692 DIR__REMOVE_NAME | DIR__SEARCH, &ad); 1693 if (rc) 1694 return rc; 1695 rc = avc_has_perm(sid, old_isec->sid, 1696 old_isec->sclass, FILE__RENAME, &ad); 1697 if (rc) 1698 return rc; 1699 if (old_is_dir && new_dir != old_dir) { 1700 rc = avc_has_perm(sid, old_isec->sid, 1701 old_isec->sclass, DIR__REPARENT, &ad); 1702 if (rc) 1703 return rc; 1704 } 1705 1706 ad.u.dentry = new_dentry; 1707 av = DIR__ADD_NAME | DIR__SEARCH; 1708 if (new_dentry->d_inode) 1709 av |= DIR__REMOVE_NAME; 1710 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad); 1711 if (rc) 1712 return rc; 1713 if (new_dentry->d_inode) { 1714 new_isec = new_dentry->d_inode->i_security; 1715 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode); 1716 rc = avc_has_perm(sid, new_isec->sid, 1717 new_isec->sclass, 1718 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); 1719 if (rc) 1720 return rc; 1721 } 1722 1723 return 0; 1724 } 1725 1726 /* Check whether a task can perform a filesystem operation. */ 1727 static int superblock_has_perm(const struct cred *cred, 1728 struct super_block *sb, 1729 u32 perms, 1730 struct common_audit_data *ad) 1731 { 1732 struct superblock_security_struct *sbsec; 1733 u32 sid = cred_sid(cred); 1734 1735 sbsec = sb->s_security; 1736 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); 1737 } 1738 1739 /* Convert a Linux mode and permission mask to an access vector. */ 1740 static inline u32 file_mask_to_av(int mode, int mask) 1741 { 1742 u32 av = 0; 1743 1744 if (!S_ISDIR(mode)) { 1745 if (mask & MAY_EXEC) 1746 av |= FILE__EXECUTE; 1747 if (mask & MAY_READ) 1748 av |= FILE__READ; 1749 1750 if (mask & MAY_APPEND) 1751 av |= FILE__APPEND; 1752 else if (mask & MAY_WRITE) 1753 av |= FILE__WRITE; 1754 1755 } else { 1756 if (mask & MAY_EXEC) 1757 av |= DIR__SEARCH; 1758 if (mask & MAY_WRITE) 1759 av |= DIR__WRITE; 1760 if (mask & MAY_READ) 1761 av |= DIR__READ; 1762 } 1763 1764 return av; 1765 } 1766 1767 /* Convert a Linux file to an access vector. */ 1768 static inline u32 file_to_av(struct file *file) 1769 { 1770 u32 av = 0; 1771 1772 if (file->f_mode & FMODE_READ) 1773 av |= FILE__READ; 1774 if (file->f_mode & FMODE_WRITE) { 1775 if (file->f_flags & O_APPEND) 1776 av |= FILE__APPEND; 1777 else 1778 av |= FILE__WRITE; 1779 } 1780 if (!av) { 1781 /* 1782 * Special file opened with flags 3 for ioctl-only use. 1783 */ 1784 av = FILE__IOCTL; 1785 } 1786 1787 return av; 1788 } 1789 1790 /* 1791 * Convert a file to an access vector and include the correct open 1792 * open permission. 1793 */ 1794 static inline u32 open_file_to_av(struct file *file) 1795 { 1796 u32 av = file_to_av(file); 1797 1798 if (selinux_policycap_openperm) 1799 av |= FILE__OPEN; 1800 1801 return av; 1802 } 1803 1804 /* Hook functions begin here. */ 1805 1806 static int selinux_ptrace_access_check(struct task_struct *child, 1807 unsigned int mode) 1808 { 1809 int rc; 1810 1811 rc = cap_ptrace_access_check(child, mode); 1812 if (rc) 1813 return rc; 1814 1815 if (mode & PTRACE_MODE_READ) { 1816 u32 sid = current_sid(); 1817 u32 csid = task_sid(child); 1818 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL); 1819 } 1820 1821 return current_has_perm(child, PROCESS__PTRACE); 1822 } 1823 1824 static int selinux_ptrace_traceme(struct task_struct *parent) 1825 { 1826 int rc; 1827 1828 rc = cap_ptrace_traceme(parent); 1829 if (rc) 1830 return rc; 1831 1832 return task_has_perm(parent, current, PROCESS__PTRACE); 1833 } 1834 1835 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, 1836 kernel_cap_t *inheritable, kernel_cap_t *permitted) 1837 { 1838 int error; 1839 1840 error = current_has_perm(target, PROCESS__GETCAP); 1841 if (error) 1842 return error; 1843 1844 return cap_capget(target, effective, inheritable, permitted); 1845 } 1846 1847 static int selinux_capset(struct cred *new, const struct cred *old, 1848 const kernel_cap_t *effective, 1849 const kernel_cap_t *inheritable, 1850 const kernel_cap_t *permitted) 1851 { 1852 int error; 1853 1854 error = cap_capset(new, old, 1855 effective, inheritable, permitted); 1856 if (error) 1857 return error; 1858 1859 return cred_has_perm(old, new, PROCESS__SETCAP); 1860 } 1861 1862 /* 1863 * (This comment used to live with the selinux_task_setuid hook, 1864 * which was removed). 1865 * 1866 * Since setuid only affects the current process, and since the SELinux 1867 * controls are not based on the Linux identity attributes, SELinux does not 1868 * need to control this operation. However, SELinux does control the use of 1869 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook. 1870 */ 1871 1872 static int selinux_capable(const struct cred *cred, struct user_namespace *ns, 1873 int cap, int audit) 1874 { 1875 int rc; 1876 1877 rc = cap_capable(cred, ns, cap, audit); 1878 if (rc) 1879 return rc; 1880 1881 return cred_has_capability(cred, cap, audit); 1882 } 1883 1884 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb) 1885 { 1886 const struct cred *cred = current_cred(); 1887 int rc = 0; 1888 1889 if (!sb) 1890 return 0; 1891 1892 switch (cmds) { 1893 case Q_SYNC: 1894 case Q_QUOTAON: 1895 case Q_QUOTAOFF: 1896 case Q_SETINFO: 1897 case Q_SETQUOTA: 1898 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL); 1899 break; 1900 case Q_GETFMT: 1901 case Q_GETINFO: 1902 case Q_GETQUOTA: 1903 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL); 1904 break; 1905 default: 1906 rc = 0; /* let the kernel handle invalid cmds */ 1907 break; 1908 } 1909 return rc; 1910 } 1911 1912 static int selinux_quota_on(struct dentry *dentry) 1913 { 1914 const struct cred *cred = current_cred(); 1915 1916 return dentry_has_perm(cred, dentry, FILE__QUOTAON); 1917 } 1918 1919 static int selinux_syslog(int type) 1920 { 1921 int rc; 1922 1923 switch (type) { 1924 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */ 1925 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */ 1926 rc = task_has_system(current, SYSTEM__SYSLOG_READ); 1927 break; 1928 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */ 1929 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */ 1930 /* Set level of messages printed to console */ 1931 case SYSLOG_ACTION_CONSOLE_LEVEL: 1932 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE); 1933 break; 1934 case SYSLOG_ACTION_CLOSE: /* Close log */ 1935 case SYSLOG_ACTION_OPEN: /* Open log */ 1936 case SYSLOG_ACTION_READ: /* Read from log */ 1937 case SYSLOG_ACTION_READ_CLEAR: /* Read/clear last kernel messages */ 1938 case SYSLOG_ACTION_CLEAR: /* Clear ring buffer */ 1939 default: 1940 rc = task_has_system(current, SYSTEM__SYSLOG_MOD); 1941 break; 1942 } 1943 return rc; 1944 } 1945 1946 /* 1947 * Check that a process has enough memory to allocate a new virtual 1948 * mapping. 0 means there is enough memory for the allocation to 1949 * succeed and -ENOMEM implies there is not. 1950 * 1951 * Do not audit the selinux permission check, as this is applied to all 1952 * processes that allocate mappings. 1953 */ 1954 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) 1955 { 1956 int rc, cap_sys_admin = 0; 1957 1958 rc = selinux_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN, 1959 SECURITY_CAP_NOAUDIT); 1960 if (rc == 0) 1961 cap_sys_admin = 1; 1962 1963 return __vm_enough_memory(mm, pages, cap_sys_admin); 1964 } 1965 1966 /* binprm security operations */ 1967 1968 static int selinux_bprm_set_creds(struct linux_binprm *bprm) 1969 { 1970 const struct task_security_struct *old_tsec; 1971 struct task_security_struct *new_tsec; 1972 struct inode_security_struct *isec; 1973 struct common_audit_data ad; 1974 struct inode *inode = bprm->file->f_path.dentry->d_inode; 1975 int rc; 1976 1977 rc = cap_bprm_set_creds(bprm); 1978 if (rc) 1979 return rc; 1980 1981 /* SELinux context only depends on initial program or script and not 1982 * the script interpreter */ 1983 if (bprm->cred_prepared) 1984 return 0; 1985 1986 old_tsec = current_security(); 1987 new_tsec = bprm->cred->security; 1988 isec = inode->i_security; 1989 1990 /* Default to the current task SID. */ 1991 new_tsec->sid = old_tsec->sid; 1992 new_tsec->osid = old_tsec->sid; 1993 1994 /* Reset fs, key, and sock SIDs on execve. */ 1995 new_tsec->create_sid = 0; 1996 new_tsec->keycreate_sid = 0; 1997 new_tsec->sockcreate_sid = 0; 1998 1999 if (old_tsec->exec_sid) { 2000 new_tsec->sid = old_tsec->exec_sid; 2001 /* Reset exec SID on execve. */ 2002 new_tsec->exec_sid = 0; 2003 } else { 2004 /* Check for a default transition on this program. */ 2005 rc = security_transition_sid(old_tsec->sid, isec->sid, 2006 SECCLASS_PROCESS, NULL, 2007 &new_tsec->sid); 2008 if (rc) 2009 return rc; 2010 } 2011 2012 COMMON_AUDIT_DATA_INIT(&ad, PATH); 2013 ad.u.path = bprm->file->f_path; 2014 2015 if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) 2016 new_tsec->sid = old_tsec->sid; 2017 2018 if (new_tsec->sid == old_tsec->sid) { 2019 rc = avc_has_perm(old_tsec->sid, isec->sid, 2020 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); 2021 if (rc) 2022 return rc; 2023 } else { 2024 /* Check permissions for the transition. */ 2025 rc = avc_has_perm(old_tsec->sid, new_tsec->sid, 2026 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); 2027 if (rc) 2028 return rc; 2029 2030 rc = avc_has_perm(new_tsec->sid, isec->sid, 2031 SECCLASS_FILE, FILE__ENTRYPOINT, &ad); 2032 if (rc) 2033 return rc; 2034 2035 /* Check for shared state */ 2036 if (bprm->unsafe & LSM_UNSAFE_SHARE) { 2037 rc = avc_has_perm(old_tsec->sid, new_tsec->sid, 2038 SECCLASS_PROCESS, PROCESS__SHARE, 2039 NULL); 2040 if (rc) 2041 return -EPERM; 2042 } 2043 2044 /* Make sure that anyone attempting to ptrace over a task that 2045 * changes its SID has the appropriate permit */ 2046 if (bprm->unsafe & 2047 (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { 2048 struct task_struct *tracer; 2049 struct task_security_struct *sec; 2050 u32 ptsid = 0; 2051 2052 rcu_read_lock(); 2053 tracer = ptrace_parent(current); 2054 if (likely(tracer != NULL)) { 2055 sec = __task_cred(tracer)->security; 2056 ptsid = sec->sid; 2057 } 2058 rcu_read_unlock(); 2059 2060 if (ptsid != 0) { 2061 rc = avc_has_perm(ptsid, new_tsec->sid, 2062 SECCLASS_PROCESS, 2063 PROCESS__PTRACE, NULL); 2064 if (rc) 2065 return -EPERM; 2066 } 2067 } 2068 2069 /* Clear any possibly unsafe personality bits on exec: */ 2070 bprm->per_clear |= PER_CLEAR_ON_SETID; 2071 } 2072 2073 return 0; 2074 } 2075 2076 static int selinux_bprm_secureexec(struct linux_binprm *bprm) 2077 { 2078 const struct task_security_struct *tsec = current_security(); 2079 u32 sid, osid; 2080 int atsecure = 0; 2081 2082 sid = tsec->sid; 2083 osid = tsec->osid; 2084 2085 if (osid != sid) { 2086 /* Enable secure mode for SIDs transitions unless 2087 the noatsecure permission is granted between 2088 the two SIDs, i.e. ahp returns 0. */ 2089 atsecure = avc_has_perm(osid, sid, 2090 SECCLASS_PROCESS, 2091 PROCESS__NOATSECURE, NULL); 2092 } 2093 2094 return (atsecure || cap_bprm_secureexec(bprm)); 2095 } 2096 2097 /* Derived from fs/exec.c:flush_old_files. */ 2098 static inline void flush_unauthorized_files(const struct cred *cred, 2099 struct files_struct *files) 2100 { 2101 struct common_audit_data ad; 2102 struct file *file, *devnull = NULL; 2103 struct tty_struct *tty; 2104 struct fdtable *fdt; 2105 long j = -1; 2106 int drop_tty = 0; 2107 2108 tty = get_current_tty(); 2109 if (tty) { 2110 spin_lock(&tty_files_lock); 2111 if (!list_empty(&tty->tty_files)) { 2112 struct tty_file_private *file_priv; 2113 struct inode *inode; 2114 2115 /* Revalidate access to controlling tty. 2116 Use inode_has_perm on the tty inode directly rather 2117 than using file_has_perm, as this particular open 2118 file may belong to another process and we are only 2119 interested in the inode-based check here. */ 2120 file_priv = list_first_entry(&tty->tty_files, 2121 struct tty_file_private, list); 2122 file = file_priv->file; 2123 inode = file->f_path.dentry->d_inode; 2124 if (inode_has_perm_noadp(cred, inode, 2125 FILE__READ | FILE__WRITE, 0)) { 2126 drop_tty = 1; 2127 } 2128 } 2129 spin_unlock(&tty_files_lock); 2130 tty_kref_put(tty); 2131 } 2132 /* Reset controlling tty. */ 2133 if (drop_tty) 2134 no_tty(); 2135 2136 /* Revalidate access to inherited open files. */ 2137 2138 COMMON_AUDIT_DATA_INIT(&ad, INODE); 2139 2140 spin_lock(&files->file_lock); 2141 for (;;) { 2142 unsigned long set, i; 2143 int fd; 2144 2145 j++; 2146 i = j * __NFDBITS; 2147 fdt = files_fdtable(files); 2148 if (i >= fdt->max_fds) 2149 break; 2150 set = fdt->open_fds->fds_bits[j]; 2151 if (!set) 2152 continue; 2153 spin_unlock(&files->file_lock); 2154 for ( ; set ; i++, set >>= 1) { 2155 if (set & 1) { 2156 file = fget(i); 2157 if (!file) 2158 continue; 2159 if (file_has_perm(cred, 2160 file, 2161 file_to_av(file))) { 2162 sys_close(i); 2163 fd = get_unused_fd(); 2164 if (fd != i) { 2165 if (fd >= 0) 2166 put_unused_fd(fd); 2167 fput(file); 2168 continue; 2169 } 2170 if (devnull) { 2171 get_file(devnull); 2172 } else { 2173 devnull = dentry_open( 2174 dget(selinux_null), 2175 mntget(selinuxfs_mount), 2176 O_RDWR, cred); 2177 if (IS_ERR(devnull)) { 2178 devnull = NULL; 2179 put_unused_fd(fd); 2180 fput(file); 2181 continue; 2182 } 2183 } 2184 fd_install(fd, devnull); 2185 } 2186 fput(file); 2187 } 2188 } 2189 spin_lock(&files->file_lock); 2190 2191 } 2192 spin_unlock(&files->file_lock); 2193 } 2194 2195 /* 2196 * Prepare a process for imminent new credential changes due to exec 2197 */ 2198 static void selinux_bprm_committing_creds(struct linux_binprm *bprm) 2199 { 2200 struct task_security_struct *new_tsec; 2201 struct rlimit *rlim, *initrlim; 2202 int rc, i; 2203 2204 new_tsec = bprm->cred->security; 2205 if (new_tsec->sid == new_tsec->osid) 2206 return; 2207 2208 /* Close files for which the new task SID is not authorized. */ 2209 flush_unauthorized_files(bprm->cred, current->files); 2210 2211 /* Always clear parent death signal on SID transitions. */ 2212 current->pdeath_signal = 0; 2213 2214 /* Check whether the new SID can inherit resource limits from the old 2215 * SID. If not, reset all soft limits to the lower of the current 2216 * task's hard limit and the init task's soft limit. 2217 * 2218 * Note that the setting of hard limits (even to lower them) can be 2219 * controlled by the setrlimit check. The inclusion of the init task's 2220 * soft limit into the computation is to avoid resetting soft limits 2221 * higher than the default soft limit for cases where the default is 2222 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. 2223 */ 2224 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, 2225 PROCESS__RLIMITINH, NULL); 2226 if (rc) { 2227 /* protect against do_prlimit() */ 2228 task_lock(current); 2229 for (i = 0; i < RLIM_NLIMITS; i++) { 2230 rlim = current->signal->rlim + i; 2231 initrlim = init_task.signal->rlim + i; 2232 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); 2233 } 2234 task_unlock(current); 2235 update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); 2236 } 2237 } 2238 2239 /* 2240 * Clean up the process immediately after the installation of new credentials 2241 * due to exec 2242 */ 2243 static void selinux_bprm_committed_creds(struct linux_binprm *bprm) 2244 { 2245 const struct task_security_struct *tsec = current_security(); 2246 struct itimerval itimer; 2247 u32 osid, sid; 2248 int rc, i; 2249 2250 osid = tsec->osid; 2251 sid = tsec->sid; 2252 2253 if (sid == osid) 2254 return; 2255 2256 /* Check whether the new SID can inherit signal state from the old SID. 2257 * If not, clear itimers to avoid subsequent signal generation and 2258 * flush and unblock signals. 2259 * 2260 * This must occur _after_ the task SID has been updated so that any 2261 * kill done after the flush will be checked against the new SID. 2262 */ 2263 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); 2264 if (rc) { 2265 memset(&itimer, 0, sizeof itimer); 2266 for (i = 0; i < 3; i++) 2267 do_setitimer(i, &itimer, NULL); 2268 spin_lock_irq(¤t->sighand->siglock); 2269 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) { 2270 __flush_signals(current); 2271 flush_signal_handlers(current, 1); 2272 sigemptyset(¤t->blocked); 2273 } 2274 spin_unlock_irq(¤t->sighand->siglock); 2275 } 2276 2277 /* Wake up the parent if it is waiting so that it can recheck 2278 * wait permission to the new task SID. */ 2279 read_lock(&tasklist_lock); 2280 __wake_up_parent(current, current->real_parent); 2281 read_unlock(&tasklist_lock); 2282 } 2283 2284 /* superblock security operations */ 2285 2286 static int selinux_sb_alloc_security(struct super_block *sb) 2287 { 2288 return superblock_alloc_security(sb); 2289 } 2290 2291 static void selinux_sb_free_security(struct super_block *sb) 2292 { 2293 superblock_free_security(sb); 2294 } 2295 2296 static inline int match_prefix(char *prefix, int plen, char *option, int olen) 2297 { 2298 if (plen > olen) 2299 return 0; 2300 2301 return !memcmp(prefix, option, plen); 2302 } 2303 2304 static inline int selinux_option(char *option, int len) 2305 { 2306 return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) || 2307 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) || 2308 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) || 2309 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) || 2310 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len)); 2311 } 2312 2313 static inline void take_option(char **to, char *from, int *first, int len) 2314 { 2315 if (!*first) { 2316 **to = ','; 2317 *to += 1; 2318 } else 2319 *first = 0; 2320 memcpy(*to, from, len); 2321 *to += len; 2322 } 2323 2324 static inline void take_selinux_option(char **to, char *from, int *first, 2325 int len) 2326 { 2327 int current_size = 0; 2328 2329 if (!*first) { 2330 **to = '|'; 2331 *to += 1; 2332 } else 2333 *first = 0; 2334 2335 while (current_size < len) { 2336 if (*from != '"') { 2337 **to = *from; 2338 *to += 1; 2339 } 2340 from += 1; 2341 current_size += 1; 2342 } 2343 } 2344 2345 static int selinux_sb_copy_data(char *orig, char *copy) 2346 { 2347 int fnosec, fsec, rc = 0; 2348 char *in_save, *in_curr, *in_end; 2349 char *sec_curr, *nosec_save, *nosec; 2350 int open_quote = 0; 2351 2352 in_curr = orig; 2353 sec_curr = copy; 2354 2355 nosec = (char *)get_zeroed_page(GFP_KERNEL); 2356 if (!nosec) { 2357 rc = -ENOMEM; 2358 goto out; 2359 } 2360 2361 nosec_save = nosec; 2362 fnosec = fsec = 1; 2363 in_save = in_end = orig; 2364 2365 do { 2366 if (*in_end == '"') 2367 open_quote = !open_quote; 2368 if ((*in_end == ',' && open_quote == 0) || 2369 *in_end == '\0') { 2370 int len = in_end - in_curr; 2371 2372 if (selinux_option(in_curr, len)) 2373 take_selinux_option(&sec_curr, in_curr, &fsec, len); 2374 else 2375 take_option(&nosec, in_curr, &fnosec, len); 2376 2377 in_curr = in_end + 1; 2378 } 2379 } while (*in_end++); 2380 2381 strcpy(in_save, nosec_save); 2382 free_page((unsigned long)nosec_save); 2383 out: 2384 return rc; 2385 } 2386 2387 static int selinux_sb_remount(struct super_block *sb, void *data) 2388 { 2389 int rc, i, *flags; 2390 struct security_mnt_opts opts; 2391 char *secdata, **mount_options; 2392 struct superblock_security_struct *sbsec = sb->s_security; 2393 2394 if (!(sbsec->flags & SE_SBINITIALIZED)) 2395 return 0; 2396 2397 if (!data) 2398 return 0; 2399 2400 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) 2401 return 0; 2402 2403 security_init_mnt_opts(&opts); 2404 secdata = alloc_secdata(); 2405 if (!secdata) 2406 return -ENOMEM; 2407 rc = selinux_sb_copy_data(data, secdata); 2408 if (rc) 2409 goto out_free_secdata; 2410 2411 rc = selinux_parse_opts_str(secdata, &opts); 2412 if (rc) 2413 goto out_free_secdata; 2414 2415 mount_options = opts.mnt_opts; 2416 flags = opts.mnt_opts_flags; 2417 2418 for (i = 0; i < opts.num_mnt_opts; i++) { 2419 u32 sid; 2420 size_t len; 2421 2422 if (flags[i] == SE_SBLABELSUPP) 2423 continue; 2424 len = strlen(mount_options[i]); 2425 rc = security_context_to_sid(mount_options[i], len, &sid); 2426 if (rc) { 2427 printk(KERN_WARNING "SELinux: security_context_to_sid" 2428 "(%s) failed for (dev %s, type %s) errno=%d\n", 2429 mount_options[i], sb->s_id, sb->s_type->name, rc); 2430 goto out_free_opts; 2431 } 2432 rc = -EINVAL; 2433 switch (flags[i]) { 2434 case FSCONTEXT_MNT: 2435 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid)) 2436 goto out_bad_option; 2437 break; 2438 case CONTEXT_MNT: 2439 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid)) 2440 goto out_bad_option; 2441 break; 2442 case ROOTCONTEXT_MNT: { 2443 struct inode_security_struct *root_isec; 2444 root_isec = sb->s_root->d_inode->i_security; 2445 2446 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid)) 2447 goto out_bad_option; 2448 break; 2449 } 2450 case DEFCONTEXT_MNT: 2451 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid)) 2452 goto out_bad_option; 2453 break; 2454 default: 2455 goto out_free_opts; 2456 } 2457 } 2458 2459 rc = 0; 2460 out_free_opts: 2461 security_free_mnt_opts(&opts); 2462 out_free_secdata: 2463 free_secdata(secdata); 2464 return rc; 2465 out_bad_option: 2466 printk(KERN_WARNING "SELinux: unable to change security options " 2467 "during remount (dev %s, type=%s)\n", sb->s_id, 2468 sb->s_type->name); 2469 goto out_free_opts; 2470 } 2471 2472 static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data) 2473 { 2474 const struct cred *cred = current_cred(); 2475 struct common_audit_data ad; 2476 int rc; 2477 2478 rc = superblock_doinit(sb, data); 2479 if (rc) 2480 return rc; 2481 2482 /* Allow all mounts performed by the kernel */ 2483 if (flags & MS_KERNMOUNT) 2484 return 0; 2485 2486 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 2487 ad.u.dentry = sb->s_root; 2488 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad); 2489 } 2490 2491 static int selinux_sb_statfs(struct dentry *dentry) 2492 { 2493 const struct cred *cred = current_cred(); 2494 struct common_audit_data ad; 2495 2496 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 2497 ad.u.dentry = dentry->d_sb->s_root; 2498 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); 2499 } 2500 2501 static int selinux_mount(char *dev_name, 2502 struct path *path, 2503 char *type, 2504 unsigned long flags, 2505 void *data) 2506 { 2507 const struct cred *cred = current_cred(); 2508 2509 if (flags & MS_REMOUNT) 2510 return superblock_has_perm(cred, path->dentry->d_sb, 2511 FILESYSTEM__REMOUNT, NULL); 2512 else 2513 return path_has_perm(cred, path, FILE__MOUNTON); 2514 } 2515 2516 static int selinux_umount(struct vfsmount *mnt, int flags) 2517 { 2518 const struct cred *cred = current_cred(); 2519 2520 return superblock_has_perm(cred, mnt->mnt_sb, 2521 FILESYSTEM__UNMOUNT, NULL); 2522 } 2523 2524 /* inode security operations */ 2525 2526 static int selinux_inode_alloc_security(struct inode *inode) 2527 { 2528 return inode_alloc_security(inode); 2529 } 2530 2531 static void selinux_inode_free_security(struct inode *inode) 2532 { 2533 inode_free_security(inode); 2534 } 2535 2536 static int selinux_inode_init_security(struct inode *inode, struct inode *dir, 2537 const struct qstr *qstr, char **name, 2538 void **value, size_t *len) 2539 { 2540 const struct task_security_struct *tsec = current_security(); 2541 struct inode_security_struct *dsec; 2542 struct superblock_security_struct *sbsec; 2543 u32 sid, newsid, clen; 2544 int rc; 2545 char *namep = NULL, *context; 2546 2547 dsec = dir->i_security; 2548 sbsec = dir->i_sb->s_security; 2549 2550 sid = tsec->sid; 2551 newsid = tsec->create_sid; 2552 2553 if ((sbsec->flags & SE_SBINITIALIZED) && 2554 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) 2555 newsid = sbsec->mntpoint_sid; 2556 else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) { 2557 rc = security_transition_sid(sid, dsec->sid, 2558 inode_mode_to_security_class(inode->i_mode), 2559 qstr, &newsid); 2560 if (rc) { 2561 printk(KERN_WARNING "%s: " 2562 "security_transition_sid failed, rc=%d (dev=%s " 2563 "ino=%ld)\n", 2564 __func__, 2565 -rc, inode->i_sb->s_id, inode->i_ino); 2566 return rc; 2567 } 2568 } 2569 2570 /* Possibly defer initialization to selinux_complete_init. */ 2571 if (sbsec->flags & SE_SBINITIALIZED) { 2572 struct inode_security_struct *isec = inode->i_security; 2573 isec->sclass = inode_mode_to_security_class(inode->i_mode); 2574 isec->sid = newsid; 2575 isec->initialized = 1; 2576 } 2577 2578 if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP)) 2579 return -EOPNOTSUPP; 2580 2581 if (name) { 2582 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS); 2583 if (!namep) 2584 return -ENOMEM; 2585 *name = namep; 2586 } 2587 2588 if (value && len) { 2589 rc = security_sid_to_context_force(newsid, &context, &clen); 2590 if (rc) { 2591 kfree(namep); 2592 return rc; 2593 } 2594 *value = context; 2595 *len = clen; 2596 } 2597 2598 return 0; 2599 } 2600 2601 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) 2602 { 2603 return may_create(dir, dentry, SECCLASS_FILE); 2604 } 2605 2606 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) 2607 { 2608 return may_link(dir, old_dentry, MAY_LINK); 2609 } 2610 2611 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) 2612 { 2613 return may_link(dir, dentry, MAY_UNLINK); 2614 } 2615 2616 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) 2617 { 2618 return may_create(dir, dentry, SECCLASS_LNK_FILE); 2619 } 2620 2621 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask) 2622 { 2623 return may_create(dir, dentry, SECCLASS_DIR); 2624 } 2625 2626 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) 2627 { 2628 return may_link(dir, dentry, MAY_RMDIR); 2629 } 2630 2631 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) 2632 { 2633 return may_create(dir, dentry, inode_mode_to_security_class(mode)); 2634 } 2635 2636 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, 2637 struct inode *new_inode, struct dentry *new_dentry) 2638 { 2639 return may_rename(old_inode, old_dentry, new_inode, new_dentry); 2640 } 2641 2642 static int selinux_inode_readlink(struct dentry *dentry) 2643 { 2644 const struct cred *cred = current_cred(); 2645 2646 return dentry_has_perm(cred, dentry, FILE__READ); 2647 } 2648 2649 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata) 2650 { 2651 const struct cred *cred = current_cred(); 2652 2653 return dentry_has_perm(cred, dentry, FILE__READ); 2654 } 2655 2656 static int selinux_inode_permission(struct inode *inode, int mask) 2657 { 2658 const struct cred *cred = current_cred(); 2659 struct common_audit_data ad; 2660 u32 perms; 2661 bool from_access; 2662 unsigned flags = mask & MAY_NOT_BLOCK; 2663 2664 from_access = mask & MAY_ACCESS; 2665 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); 2666 2667 /* No permission to check. Existence test. */ 2668 if (!mask) 2669 return 0; 2670 2671 COMMON_AUDIT_DATA_INIT(&ad, INODE); 2672 ad.u.inode = inode; 2673 2674 if (from_access) 2675 ad.selinux_audit_data.auditdeny |= FILE__AUDIT_ACCESS; 2676 2677 perms = file_mask_to_av(inode->i_mode, mask); 2678 2679 return inode_has_perm(cred, inode, perms, &ad, flags); 2680 } 2681 2682 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) 2683 { 2684 const struct cred *cred = current_cred(); 2685 unsigned int ia_valid = iattr->ia_valid; 2686 2687 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ 2688 if (ia_valid & ATTR_FORCE) { 2689 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | 2690 ATTR_FORCE); 2691 if (!ia_valid) 2692 return 0; 2693 } 2694 2695 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | 2696 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) 2697 return dentry_has_perm(cred, dentry, FILE__SETATTR); 2698 2699 return dentry_has_perm(cred, dentry, FILE__WRITE); 2700 } 2701 2702 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) 2703 { 2704 const struct cred *cred = current_cred(); 2705 struct path path; 2706 2707 path.dentry = dentry; 2708 path.mnt = mnt; 2709 2710 return path_has_perm(cred, &path, FILE__GETATTR); 2711 } 2712 2713 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name) 2714 { 2715 const struct cred *cred = current_cred(); 2716 2717 if (!strncmp(name, XATTR_SECURITY_PREFIX, 2718 sizeof XATTR_SECURITY_PREFIX - 1)) { 2719 if (!strcmp(name, XATTR_NAME_CAPS)) { 2720 if (!capable(CAP_SETFCAP)) 2721 return -EPERM; 2722 } else if (!capable(CAP_SYS_ADMIN)) { 2723 /* A different attribute in the security namespace. 2724 Restrict to administrator. */ 2725 return -EPERM; 2726 } 2727 } 2728 2729 /* Not an attribute we recognize, so just check the 2730 ordinary setattr permission. */ 2731 return dentry_has_perm(cred, dentry, FILE__SETATTR); 2732 } 2733 2734 static int selinux_inode_setxattr(struct dentry *dentry, const char *name, 2735 const void *value, size_t size, int flags) 2736 { 2737 struct inode *inode = dentry->d_inode; 2738 struct inode_security_struct *isec = inode->i_security; 2739 struct superblock_security_struct *sbsec; 2740 struct common_audit_data ad; 2741 u32 newsid, sid = current_sid(); 2742 int rc = 0; 2743 2744 if (strcmp(name, XATTR_NAME_SELINUX)) 2745 return selinux_inode_setotherxattr(dentry, name); 2746 2747 sbsec = inode->i_sb->s_security; 2748 if (!(sbsec->flags & SE_SBLABELSUPP)) 2749 return -EOPNOTSUPP; 2750 2751 if (!inode_owner_or_capable(inode)) 2752 return -EPERM; 2753 2754 COMMON_AUDIT_DATA_INIT(&ad, DENTRY); 2755 ad.u.dentry = dentry; 2756 2757 rc = avc_has_perm(sid, isec->sid, isec->sclass, 2758 FILE__RELABELFROM, &ad); 2759 if (rc) 2760 return rc; 2761 2762 rc = security_context_to_sid(value, size, &newsid); 2763 if (rc == -EINVAL) { 2764 if (!capable(CAP_MAC_ADMIN)) 2765 return rc; 2766 rc = security_context_to_sid_force(value, size, &newsid); 2767 } 2768 if (rc) 2769 return rc; 2770 2771 rc = avc_has_perm(sid, newsid, isec->sclass, 2772 FILE__RELABELTO, &ad); 2773 if (rc) 2774 return rc; 2775 2776 rc = security_validate_transition(isec->sid, newsid, sid, 2777 isec->sclass); 2778 if (rc) 2779 return rc; 2780 2781 return avc_has_perm(newsid, 2782 sbsec->sid, 2783 SECCLASS_FILESYSTEM, 2784 FILESYSTEM__ASSOCIATE, 2785 &ad); 2786 } 2787 2788 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, 2789 const void *value, size_t size, 2790 int flags) 2791 { 2792 struct inode *inode = dentry->d_inode; 2793 struct inode_security_struct *isec = inode->i_security; 2794 u32 newsid; 2795 int rc; 2796 2797 if (strcmp(name, XATTR_NAME_SELINUX)) { 2798 /* Not an attribute we recognize, so nothing to do. */ 2799 return; 2800 } 2801 2802 rc = security_context_to_sid_force(value, size, &newsid); 2803 if (rc) { 2804 printk(KERN_ERR "SELinux: unable to map context to SID" 2805 "for (%s, %lu), rc=%d\n", 2806 inode->i_sb->s_id, inode->i_ino, -rc); 2807 return; 2808 } 2809 2810 isec->sid = newsid; 2811 return; 2812 } 2813 2814 static int selinux_inode_getxattr(struct dentry *dentry, const char *name) 2815 { 2816 const struct cred *cred = current_cred(); 2817 2818 return dentry_has_perm(cred, dentry, FILE__GETATTR); 2819 } 2820 2821 static int selinux_inode_listxattr(struct dentry *dentry) 2822 { 2823 const struct cred *cred = current_cred(); 2824 2825 return dentry_has_perm(cred, dentry, FILE__GETATTR); 2826 } 2827 2828 static int selinux_inode_removexattr(struct dentry *dentry, const char *name) 2829 { 2830 if (strcmp(name, XATTR_NAME_SELINUX)) 2831 return selinux_inode_setotherxattr(dentry, name); 2832 2833 /* No one is allowed to remove a SELinux security label. 2834 You can change the label, but all data must be labeled. */ 2835 return -EACCES; 2836 } 2837 2838 /* 2839 * Copy the inode security context value to the user. 2840 * 2841 * Permission check is handled by selinux_inode_getxattr hook. 2842 */ 2843 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc) 2844 { 2845 u32 size; 2846 int error; 2847 char *context = NULL; 2848 struct inode_security_struct *isec = inode->i_security; 2849 2850 if (strcmp(name, XATTR_SELINUX_SUFFIX)) 2851 return -EOPNOTSUPP; 2852 2853 /* 2854 * If the caller has CAP_MAC_ADMIN, then get the raw context 2855 * value even if it is not defined by current policy; otherwise, 2856 * use the in-core value under current policy. 2857 * Use the non-auditing forms of the permission checks since 2858 * getxattr may be called by unprivileged processes commonly 2859 * and lack of permission just means that we fall back to the 2860 * in-core context value, not a denial. 2861 */ 2862 error = selinux_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN, 2863 SECURITY_CAP_NOAUDIT); 2864 if (!error) 2865 error = security_sid_to_context_force(isec->sid, &context, 2866 &size); 2867 else 2868 error = security_sid_to_context(isec->sid, &context, &size); 2869 if (error) 2870 return error; 2871 error = size; 2872 if (alloc) { 2873 *buffer = context; 2874 goto out_nofree; 2875 } 2876 kfree(context); 2877 out_nofree: 2878 return error; 2879 } 2880 2881 static int selinux_inode_setsecurity(struct inode *inode, const char *name, 2882 const void *value, size_t size, int flags) 2883 { 2884 struct inode_security_struct *isec = inode->i_security; 2885 u32 newsid; 2886 int rc; 2887 2888 if (strcmp(name, XATTR_SELINUX_SUFFIX)) 2889 return -EOPNOTSUPP; 2890 2891 if (!value || !size) 2892 return -EACCES; 2893 2894 rc = security_context_to_sid((void *)value, size, &newsid); 2895 if (rc) 2896 return rc; 2897 2898 isec->sid = newsid; 2899 isec->initialized = 1; 2900 return 0; 2901 } 2902 2903 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) 2904 { 2905 const int len = sizeof(XATTR_NAME_SELINUX); 2906 if (buffer && len <= buffer_size) 2907 memcpy(buffer, XATTR_NAME_SELINUX, len); 2908 return len; 2909 } 2910 2911 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid) 2912 { 2913 struct inode_security_struct *isec = inode->i_security; 2914 *secid = isec->sid; 2915 } 2916 2917 /* file security operations */ 2918 2919 static int selinux_revalidate_file_permission(struct file *file, int mask) 2920 { 2921 const struct cred *cred = current_cred(); 2922 struct inode *inode = file->f_path.dentry->d_inode; 2923 2924 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ 2925 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) 2926 mask |= MAY_APPEND; 2927 2928 return file_has_perm(cred, file, 2929 file_mask_to_av(inode->i_mode, mask)); 2930 } 2931 2932 static int selinux_file_permission(struct file *file, int mask) 2933 { 2934 struct inode *inode = file->f_path.dentry->d_inode; 2935 struct file_security_struct *fsec = file->f_security; 2936 struct inode_security_struct *isec = inode->i_security; 2937 u32 sid = current_sid(); 2938 2939 if (!mask) 2940 /* No permission to check. Existence test. */ 2941 return 0; 2942 2943 if (sid == fsec->sid && fsec->isid == isec->sid && 2944 fsec->pseqno == avc_policy_seqno()) 2945 /* No change since dentry_open check. */ 2946 return 0; 2947 2948 return selinux_revalidate_file_permission(file, mask); 2949 } 2950 2951 static int selinux_file_alloc_security(struct file *file) 2952 { 2953 return file_alloc_security(file); 2954 } 2955 2956 static void selinux_file_free_security(struct file *file) 2957 { 2958 file_free_security(file); 2959 } 2960 2961 static int selinux_file_ioctl(struct file *file, unsigned int cmd, 2962 unsigned long arg) 2963 { 2964 const struct cred *cred = current_cred(); 2965 int error = 0; 2966 2967 switch (cmd) { 2968 case FIONREAD: 2969 /* fall through */ 2970 case FIBMAP: 2971 /* fall through */ 2972 case FIGETBSZ: 2973 /* fall through */ 2974 case EXT2_IOC_GETFLAGS: 2975 /* fall through */ 2976 case EXT2_IOC_GETVERSION: 2977 error = file_has_perm(cred, file, FILE__GETATTR); 2978 break; 2979 2980 case EXT2_IOC_SETFLAGS: 2981 /* fall through */ 2982 case EXT2_IOC_SETVERSION: 2983 error = file_has_perm(cred, file, FILE__SETATTR); 2984 break; 2985 2986 /* sys_ioctl() checks */ 2987 case FIONBIO: 2988 /* fall through */ 2989 case FIOASYNC: 2990 error = file_has_perm(cred, file, 0); 2991 break; 2992 2993 case KDSKBENT: 2994 case KDSKBSENT: 2995 error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG, 2996 SECURITY_CAP_AUDIT); 2997 break; 2998 2999 /* default case assumes that the command will go 3000 * to the file's ioctl() function. 3001 */ 3002 default: 3003 error = file_has_perm(cred, file, FILE__IOCTL); 3004 } 3005 return error; 3006 } 3007 3008 static int default_noexec; 3009 3010 static int file_map_prot_check(struct file *file, unsigned long prot, int shared) 3011 { 3012 const struct cred *cred = current_cred(); 3013 int rc = 0; 3014 3015 if (default_noexec && 3016 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) { 3017 /* 3018 * We are making executable an anonymous mapping or a 3019 * private file mapping that will also be writable. 3020 * This has an additional check. 3021 */ 3022 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM); 3023 if (rc) 3024 goto error; 3025 } 3026 3027 if (file) { 3028 /* read access is always possible with a mapping */ 3029 u32 av = FILE__READ; 3030 3031 /* write access only matters if the mapping is shared */ 3032 if (shared && (prot & PROT_WRITE)) 3033 av |= FILE__WRITE; 3034 3035 if (prot & PROT_EXEC) 3036 av |= FILE__EXECUTE; 3037 3038 return file_has_perm(cred, file, av); 3039 } 3040 3041 error: 3042 return rc; 3043 } 3044 3045 static int selinux_file_mmap(struct file *file, unsigned long reqprot, 3046 unsigned long prot, unsigned long flags, 3047 unsigned long addr, unsigned long addr_only) 3048 { 3049 int rc = 0; 3050 u32 sid = current_sid(); 3051 3052 /* 3053 * notice that we are intentionally putting the SELinux check before 3054 * the secondary cap_file_mmap check. This is such a likely attempt 3055 * at bad behaviour/exploit that we always want to get the AVC, even 3056 * if DAC would have also denied the operation. 3057 */ 3058 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) { 3059 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, 3060 MEMPROTECT__MMAP_ZERO, NULL); 3061 if (rc) 3062 return rc; 3063 } 3064 3065 /* do DAC check on address space usage */ 3066 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only); 3067 if (rc || addr_only) 3068 return rc; 3069 3070 if (selinux_checkreqprot) 3071 prot = reqprot; 3072 3073 return file_map_prot_check(file, prot, 3074 (flags & MAP_TYPE) == MAP_SHARED); 3075 } 3076 3077 static int selinux_file_mprotect(struct vm_area_struct *vma, 3078 unsigned long reqprot, 3079 unsigned long prot) 3080 { 3081 const struct cred *cred = current_cred(); 3082 3083 if (selinux_checkreqprot) 3084 prot = reqprot; 3085 3086 if (default_noexec && 3087 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { 3088 int rc = 0; 3089 if (vma->vm_start >= vma->vm_mm->start_brk && 3090 vma->vm_end <= vma->vm_mm->brk) { 3091 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP); 3092 } else if (!vma->vm_file && 3093 vma->vm_start <= vma->vm_mm->start_stack && 3094 vma->vm_end >= vma->vm_mm->start_stack) { 3095 rc = current_has_perm(current, PROCESS__EXECSTACK); 3096 } else if (vma->vm_file && vma->anon_vma) { 3097 /* 3098 * We are making executable a file mapping that has 3099 * had some COW done. Since pages might have been 3100 * written, check ability to execute the possibly 3101 * modified content. This typically should only 3102 * occur for text relocations. 3103 */ 3104 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD); 3105 } 3106 if (rc) 3107 return rc; 3108 } 3109 3110 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED); 3111 } 3112 3113 static int selinux_file_lock(struct file *file, unsigned int cmd) 3114 { 3115 const struct cred *cred = current_cred(); 3116 3117 return file_has_perm(cred, file, FILE__LOCK); 3118 } 3119 3120 static int selinux_file_fcntl(struct file *file, unsigned int cmd, 3121 unsigned long arg) 3122 { 3123 const struct cred *cred = current_cred(); 3124 int err = 0; 3125 3126 switch (cmd) { 3127 case F_SETFL: 3128 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) { 3129 err = -EINVAL; 3130 break; 3131 } 3132 3133 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) { 3134 err = file_has_perm(cred, file, FILE__WRITE); 3135 break; 3136 } 3137 /* fall through */ 3138 case F_SETOWN: 3139 case F_SETSIG: 3140 case F_GETFL: 3141 case F_GETOWN: 3142 case F_GETSIG: 3143 /* Just check FD__USE permission */ 3144 err = file_has_perm(cred, file, 0); 3145 break; 3146 case F_GETLK: 3147 case F_SETLK: 3148 case F_SETLKW: 3149 #if BITS_PER_LONG == 32 3150 case F_GETLK64: 3151 case F_SETLK64: 3152 case F_SETLKW64: 3153 #endif 3154 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) { 3155 err = -EINVAL; 3156 break; 3157 } 3158 err = file_has_perm(cred, file, FILE__LOCK); 3159 break; 3160 } 3161 3162 return err; 3163 } 3164 3165 static int selinux_file_set_fowner(struct file *file) 3166 { 3167 struct file_security_struct *fsec; 3168 3169 fsec = file->f_security; 3170 fsec->fown_sid = current_sid(); 3171 3172 return 0; 3173 } 3174 3175 static int selinux_file_send_sigiotask(struct task_struct *tsk, 3176 struct fown_struct *fown, int signum) 3177 { 3178 struct file *file; 3179 u32 sid = task_sid(tsk); 3180 u32 perm; 3181 struct file_security_struct *fsec; 3182 3183 /* struct fown_struct is never outside the context of a struct file */ 3184 file = container_of(fown, struct file, f_owner); 3185 3186 fsec = file->f_security; 3187 3188 if (!signum) 3189 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */ 3190 else 3191 perm = signal_to_av(signum); 3192 3193 return avc_has_perm(fsec->fown_sid, sid, 3194 SECCLASS_PROCESS, perm, NULL); 3195 } 3196 3197 static int selinux_file_receive(struct file *file) 3198 { 3199 const struct cred *cred = current_cred(); 3200 3201 return file_has_perm(cred, file, file_to_av(file)); 3202 } 3203 3204 static int selinux_dentry_open(struct file *file, const struct cred *cred) 3205 { 3206 struct file_security_struct *fsec; 3207 struct inode *inode; 3208 struct inode_security_struct *isec; 3209 3210 inode = file->f_path.dentry->d_inode; 3211 fsec = file->f_security; 3212 isec = inode->i_security; 3213 /* 3214 * Save inode label and policy sequence number 3215 * at open-time so that selinux_file_permission 3216 * can determine whether revalidation is necessary. 3217 * Task label is already saved in the file security 3218 * struct as its SID. 3219 */ 3220 fsec->isid = isec->sid; 3221 fsec->pseqno = avc_policy_seqno(); 3222 /* 3223 * Since the inode label or policy seqno may have changed 3224 * between the selinux_inode_permission check and the saving 3225 * of state above, recheck that access is still permitted. 3226 * Otherwise, access might never be revalidated against the 3227 * new inode label or new policy. 3228 * This check is not redundant - do not remove. 3229 */ 3230 return inode_has_perm_noadp(cred, inode, open_file_to_av(file), 0); 3231 } 3232 3233 /* task security operations */ 3234 3235 static int selinux_task_create(unsigned long clone_flags) 3236 { 3237 return current_has_perm(current, PROCESS__FORK); 3238 } 3239 3240 /* 3241 * allocate the SELinux part of blank credentials 3242 */ 3243 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp) 3244 { 3245 struct task_security_struct *tsec; 3246 3247 tsec = kzalloc(sizeof(struct task_security_struct), gfp); 3248 if (!tsec) 3249 return -ENOMEM; 3250 3251 cred->security = tsec; 3252 return 0; 3253 } 3254 3255 /* 3256 * detach and free the LSM part of a set of credentials 3257 */ 3258 static void selinux_cred_free(struct cred *cred) 3259 { 3260 struct task_security_struct *tsec = cred->security; 3261 3262 /* 3263 * cred->security == NULL if security_cred_alloc_blank() or 3264 * security_prepare_creds() returned an error. 3265 */ 3266 BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE); 3267 cred->security = (void *) 0x7UL; 3268 kfree(tsec); 3269 } 3270 3271 /* 3272 * prepare a new set of credentials for modification 3273 */ 3274 static int selinux_cred_prepare(struct cred *new, const struct cred *old, 3275 gfp_t gfp) 3276 { 3277 const struct task_security_struct *old_tsec; 3278 struct task_security_struct *tsec; 3279 3280 old_tsec = old->security; 3281 3282 tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp); 3283 if (!tsec) 3284 return -ENOMEM; 3285 3286 new->security = tsec; 3287 return 0; 3288 } 3289 3290 /* 3291 * transfer the SELinux data to a blank set of creds 3292 */ 3293 static void selinux_cred_transfer(struct cred *new, const struct cred *old) 3294 { 3295 const struct task_security_struct *old_tsec = old->security; 3296 struct task_security_struct *tsec = new->security; 3297 3298 *tsec = *old_tsec; 3299 } 3300 3301 /* 3302 * set the security data for a kernel service 3303 * - all the creation contexts are set to unlabelled 3304 */ 3305 static int selinux_kernel_act_as(struct cred *new, u32 secid) 3306 { 3307 struct task_security_struct *tsec = new->security; 3308 u32 sid = current_sid(); 3309 int ret; 3310 3311 ret = avc_has_perm(sid, secid, 3312 SECCLASS_KERNEL_SERVICE, 3313 KERNEL_SERVICE__USE_AS_OVERRIDE, 3314 NULL); 3315 if (ret == 0) { 3316 tsec->sid = secid; 3317 tsec->create_sid = 0; 3318 tsec->keycreate_sid = 0; 3319 tsec->sockcreate_sid = 0; 3320 } 3321 return ret; 3322 } 3323 3324 /* 3325 * set the file creation context in a security record to the same as the 3326 * objective context of the specified inode 3327 */ 3328 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode) 3329 { 3330 struct inode_security_struct *isec = inode->i_security; 3331 struct task_security_struct *tsec = new->security; 3332 u32 sid = current_sid(); 3333 int ret; 3334 3335 ret = avc_has_perm(sid, isec->sid, 3336 SECCLASS_KERNEL_SERVICE, 3337 KERNEL_SERVICE__CREATE_FILES_AS, 3338 NULL); 3339 3340 if (ret == 0) 3341 tsec->create_sid = isec->sid; 3342 return ret; 3343 } 3344 3345 static int selinux_kernel_module_request(char *kmod_name) 3346 { 3347 u32 sid; 3348 struct common_audit_data ad; 3349 3350 sid = task_sid(current); 3351 3352 COMMON_AUDIT_DATA_INIT(&ad, KMOD); 3353 ad.u.kmod_name = kmod_name; 3354 3355 return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM, 3356 SYSTEM__MODULE_REQUEST, &ad); 3357 } 3358 3359 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid) 3360 { 3361 return current_has_perm(p, PROCESS__SETPGID); 3362 } 3363 3364 static int selinux_task_getpgid(struct task_struct *p) 3365 { 3366 return current_has_perm(p, PROCESS__GETPGID); 3367 } 3368 3369 static int selinux_task_getsid(struct task_struct *p) 3370 { 3371 return current_has_perm(p, PROCESS__GETSESSION); 3372 } 3373 3374 static void selinux_task_getsecid(struct task_struct *p, u32 *secid) 3375 { 3376 *secid = task_sid(p); 3377 } 3378 3379 static int selinux_task_setnice(struct task_struct *p, int nice) 3380 { 3381 int rc; 3382 3383 rc = cap_task_setnice(p, nice); 3384 if (rc) 3385 return rc; 3386 3387 return current_has_perm(p, PROCESS__SETSCHED); 3388 } 3389 3390 static int selinux_task_setioprio(struct task_struct *p, int ioprio) 3391 { 3392 int rc; 3393 3394 rc = cap_task_setioprio(p, ioprio); 3395 if (rc) 3396 return rc; 3397 3398 return current_has_perm(p, PROCESS__SETSCHED); 3399 } 3400 3401 static int selinux_task_getioprio(struct task_struct *p) 3402 { 3403 return current_has_perm(p, PROCESS__GETSCHED); 3404 } 3405 3406 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource, 3407 struct rlimit *new_rlim) 3408 { 3409 struct rlimit *old_rlim = p->signal->rlim + resource; 3410 3411 /* Control the ability to change the hard limit (whether 3412 lowering or raising it), so that the hard limit can 3413 later be used as a safe reset point for the soft limit 3414 upon context transitions. See selinux_bprm_committing_creds. */ 3415 if (old_rlim->rlim_max != new_rlim->rlim_max) 3416 return current_has_perm(p, PROCESS__SETRLIMIT); 3417 3418 return 0; 3419 } 3420 3421 static int selinux_task_setscheduler(struct task_struct *p) 3422 { 3423 int rc; 3424 3425 rc = cap_task_setscheduler(p); 3426 if (rc) 3427 return rc; 3428 3429 return current_has_perm(p, PROCESS__SETSCHED); 3430 } 3431 3432 static int selinux_task_getscheduler(struct task_struct *p) 3433 { 3434 return current_has_perm(p, PROCESS__GETSCHED); 3435 } 3436 3437 static int selinux_task_movememory(struct task_struct *p) 3438 { 3439 return current_has_perm(p, PROCESS__SETSCHED); 3440 } 3441 3442 static int selinux_task_kill(struct task_struct *p, struct siginfo *info, 3443 int sig, u32 secid) 3444 { 3445 u32 perm; 3446 int rc; 3447 3448 if (!sig) 3449 perm = PROCESS__SIGNULL; /* null signal; existence test */ 3450 else 3451 perm = signal_to_av(sig); 3452 if (secid) 3453 rc = avc_has_perm(secid, task_sid(p), 3454 SECCLASS_PROCESS, perm, NULL); 3455 else 3456 rc = current_has_perm(p, perm); 3457 return rc; 3458 } 3459 3460 static int selinux_task_wait(struct task_struct *p) 3461 { 3462 return task_has_perm(p, current, PROCESS__SIGCHLD); 3463 } 3464 3465 static void selinux_task_to_inode(struct task_struct *p, 3466 struct inode *inode) 3467 { 3468 struct inode_security_struct *isec = inode->i_security; 3469 u32 sid = task_sid(p); 3470 3471 isec->sid = sid; 3472 isec->initialized = 1; 3473 } 3474 3475 /* Returns error only if unable to parse addresses */ 3476 static int selinux_parse_skb_ipv4(struct sk_buff *skb, 3477 struct common_audit_data *ad, u8 *proto) 3478 { 3479 int offset, ihlen, ret = -EINVAL; 3480 struct iphdr _iph, *ih; 3481 3482 offset = skb_network_offset(skb); 3483 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph); 3484 if (ih == NULL) 3485 goto out; 3486 3487 ihlen = ih->ihl * 4; 3488 if (ihlen < sizeof(_iph)) 3489 goto out; 3490 3491 ad->u.net.v4info.saddr = ih->saddr; 3492 ad->u.net.v4info.daddr = ih->daddr; 3493 ret = 0; 3494 3495 if (proto) 3496 *proto = ih->protocol; 3497 3498 switch (ih->protocol) { 3499 case IPPROTO_TCP: { 3500 struct tcphdr _tcph, *th; 3501 3502 if (ntohs(ih->frag_off) & IP_OFFSET) 3503 break; 3504 3505 offset += ihlen; 3506 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); 3507 if (th == NULL) 3508 break; 3509 3510 ad->u.net.sport = th->source; 3511 ad->u.net.dport = th->dest; 3512 break; 3513 } 3514 3515 case IPPROTO_UDP: { 3516 struct udphdr _udph, *uh; 3517 3518 if (ntohs(ih->frag_off) & IP_OFFSET) 3519 break; 3520 3521 offset += ihlen; 3522 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); 3523 if (uh == NULL) 3524 break; 3525 3526 ad->u.net.sport = uh->source; 3527 ad->u.net.dport = uh->dest; 3528 break; 3529 } 3530 3531 case IPPROTO_DCCP: { 3532 struct dccp_hdr _dccph, *dh; 3533 3534 if (ntohs(ih->frag_off) & IP_OFFSET) 3535 break; 3536 3537 offset += ihlen; 3538 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); 3539 if (dh == NULL) 3540 break; 3541 3542 ad->u.net.sport = dh->dccph_sport; 3543 ad->u.net.dport = dh->dccph_dport; 3544 break; 3545 } 3546 3547 default: 3548 break; 3549 } 3550 out: 3551 return ret; 3552 } 3553 3554 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 3555 3556 /* Returns error only if unable to parse addresses */ 3557 static int selinux_parse_skb_ipv6(struct sk_buff *skb, 3558 struct common_audit_data *ad, u8 *proto) 3559 { 3560 u8 nexthdr; 3561 int ret = -EINVAL, offset; 3562 struct ipv6hdr _ipv6h, *ip6; 3563 __be16 frag_off; 3564 3565 offset = skb_network_offset(skb); 3566 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); 3567 if (ip6 == NULL) 3568 goto out; 3569 3570 ad->u.net.v6info.saddr = ip6->saddr; 3571 ad->u.net.v6info.daddr = ip6->daddr; 3572 ret = 0; 3573 3574 nexthdr = ip6->nexthdr; 3575 offset += sizeof(_ipv6h); 3576 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); 3577 if (offset < 0) 3578 goto out; 3579 3580 if (proto) 3581 *proto = nexthdr; 3582 3583 switch (nexthdr) { 3584 case IPPROTO_TCP: { 3585 struct tcphdr _tcph, *th; 3586 3587 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); 3588 if (th == NULL) 3589 break; 3590 3591 ad->u.net.sport = th->source; 3592 ad->u.net.dport = th->dest; 3593 break; 3594 } 3595 3596 case IPPROTO_UDP: { 3597 struct udphdr _udph, *uh; 3598 3599 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); 3600 if (uh == NULL) 3601 break; 3602 3603 ad->u.net.sport = uh->source; 3604 ad->u.net.dport = uh->dest; 3605 break; 3606 } 3607 3608 case IPPROTO_DCCP: { 3609 struct dccp_hdr _dccph, *dh; 3610 3611 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); 3612 if (dh == NULL) 3613 break; 3614 3615 ad->u.net.sport = dh->dccph_sport; 3616 ad->u.net.dport = dh->dccph_dport; 3617 break; 3618 } 3619 3620 /* includes fragments */ 3621 default: 3622 break; 3623 } 3624 out: 3625 return ret; 3626 } 3627 3628 #endif /* IPV6 */ 3629 3630 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad, 3631 char **_addrp, int src, u8 *proto) 3632 { 3633 char *addrp; 3634 int ret; 3635 3636 switch (ad->u.net.family) { 3637 case PF_INET: 3638 ret = selinux_parse_skb_ipv4(skb, ad, proto); 3639 if (ret) 3640 goto parse_error; 3641 addrp = (char *)(src ? &ad->u.net.v4info.saddr : 3642 &ad->u.net.v4info.daddr); 3643 goto okay; 3644 3645 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 3646 case PF_INET6: 3647 ret = selinux_parse_skb_ipv6(skb, ad, proto); 3648 if (ret) 3649 goto parse_error; 3650 addrp = (char *)(src ? &ad->u.net.v6info.saddr : 3651 &ad->u.net.v6info.daddr); 3652 goto okay; 3653 #endif /* IPV6 */ 3654 default: 3655 addrp = NULL; 3656 goto okay; 3657 } 3658 3659 parse_error: 3660 printk(KERN_WARNING 3661 "SELinux: failure in selinux_parse_skb()," 3662 " unable to parse packet\n"); 3663 return ret; 3664 3665 okay: 3666 if (_addrp) 3667 *_addrp = addrp; 3668 return 0; 3669 } 3670 3671 /** 3672 * selinux_skb_peerlbl_sid - Determine the peer label of a packet 3673 * @skb: the packet 3674 * @family: protocol family 3675 * @sid: the packet's peer label SID 3676 * 3677 * Description: 3678 * Check the various different forms of network peer labeling and determine 3679 * the peer label/SID for the packet; most of the magic actually occurs in 3680 * the security server function security_net_peersid_cmp(). The function 3681 * returns zero if the value in @sid is valid (although it may be SECSID_NULL) 3682 * or -EACCES if @sid is invalid due to inconsistencies with the different 3683 * peer labels. 3684 * 3685 */ 3686 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) 3687 { 3688 int err; 3689 u32 xfrm_sid; 3690 u32 nlbl_sid; 3691 u32 nlbl_type; 3692 3693 selinux_skb_xfrm_sid(skb, &xfrm_sid); 3694 selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid); 3695 3696 err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid); 3697 if (unlikely(err)) { 3698 printk(KERN_WARNING 3699 "SELinux: failure in selinux_skb_peerlbl_sid()," 3700 " unable to determine packet's peer label\n"); 3701 return -EACCES; 3702 } 3703 3704 return 0; 3705 } 3706 3707 /* socket security operations */ 3708 3709 static int socket_sockcreate_sid(const struct task_security_struct *tsec, 3710 u16 secclass, u32 *socksid) 3711 { 3712 if (tsec->sockcreate_sid > SECSID_NULL) { 3713 *socksid = tsec->sockcreate_sid; 3714 return 0; 3715 } 3716 3717 return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL, 3718 socksid); 3719 } 3720 3721 static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms) 3722 { 3723 struct sk_security_struct *sksec = sk->sk_security; 3724 struct common_audit_data ad; 3725 u32 tsid = task_sid(task); 3726 3727 if (sksec->sid == SECINITSID_KERNEL) 3728 return 0; 3729 3730 COMMON_AUDIT_DATA_INIT(&ad, NET); 3731 ad.u.net.sk = sk; 3732 3733 return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad); 3734 } 3735 3736 static int selinux_socket_create(int family, int type, 3737 int protocol, int kern) 3738 { 3739 const struct task_security_struct *tsec = current_security(); 3740 u32 newsid; 3741 u16 secclass; 3742 int rc; 3743 3744 if (kern) 3745 return 0; 3746 3747 secclass = socket_type_to_security_class(family, type, protocol); 3748 rc = socket_sockcreate_sid(tsec, secclass, &newsid); 3749 if (rc) 3750 return rc; 3751 3752 return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL); 3753 } 3754 3755 static int selinux_socket_post_create(struct socket *sock, int family, 3756 int type, int protocol, int kern) 3757 { 3758 const struct task_security_struct *tsec = current_security(); 3759 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security; 3760 struct sk_security_struct *sksec; 3761 int err = 0; 3762 3763 isec->sclass = socket_type_to_security_class(family, type, protocol); 3764 3765 if (kern) 3766 isec->sid = SECINITSID_KERNEL; 3767 else { 3768 err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid)); 3769 if (err) 3770 return err; 3771 } 3772 3773 isec->initialized = 1; 3774 3775 if (sock->sk) { 3776 sksec = sock->sk->sk_security; 3777 sksec->sid = isec->sid; 3778 sksec->sclass = isec->sclass; 3779 err = selinux_netlbl_socket_post_create(sock->sk, family); 3780 } 3781 3782 return err; 3783 } 3784 3785 /* Range of port numbers used to automatically bind. 3786 Need to determine whether we should perform a name_bind 3787 permission check between the socket and the port number. */ 3788 3789 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) 3790 { 3791 struct sock *sk = sock->sk; 3792 u16 family; 3793 int err; 3794 3795 err = sock_has_perm(current, sk, SOCKET__BIND); 3796 if (err) 3797 goto out; 3798 3799 /* 3800 * If PF_INET or PF_INET6, check name_bind permission for the port. 3801 * Multiple address binding for SCTP is not supported yet: we just 3802 * check the first address now. 3803 */ 3804 family = sk->sk_family; 3805 if (family == PF_INET || family == PF_INET6) { 3806 char *addrp; 3807 struct sk_security_struct *sksec = sk->sk_security; 3808 struct common_audit_data ad; 3809 struct sockaddr_in *addr4 = NULL; 3810 struct sockaddr_in6 *addr6 = NULL; 3811 unsigned short snum; 3812 u32 sid, node_perm; 3813 3814 if (family == PF_INET) { 3815 addr4 = (struct sockaddr_in *)address; 3816 snum = ntohs(addr4->sin_port); 3817 addrp = (char *)&addr4->sin_addr.s_addr; 3818 } else { 3819 addr6 = (struct sockaddr_in6 *)address; 3820 snum = ntohs(addr6->sin6_port); 3821 addrp = (char *)&addr6->sin6_addr.s6_addr; 3822 } 3823 3824 if (snum) { 3825 int low, high; 3826 3827 inet_get_local_port_range(&low, &high); 3828 3829 if (snum < max(PROT_SOCK, low) || snum > high) { 3830 err = sel_netport_sid(sk->sk_protocol, 3831 snum, &sid); 3832 if (err) 3833 goto out; 3834 COMMON_AUDIT_DATA_INIT(&ad, NET); 3835 ad.u.net.sport = htons(snum); 3836 ad.u.net.family = family; 3837 err = avc_has_perm(sksec->sid, sid, 3838 sksec->sclass, 3839 SOCKET__NAME_BIND, &ad); 3840 if (err) 3841 goto out; 3842 } 3843 } 3844 3845 switch (sksec->sclass) { 3846 case SECCLASS_TCP_SOCKET: 3847 node_perm = TCP_SOCKET__NODE_BIND; 3848 break; 3849 3850 case SECCLASS_UDP_SOCKET: 3851 node_perm = UDP_SOCKET__NODE_BIND; 3852 break; 3853 3854 case SECCLASS_DCCP_SOCKET: 3855 node_perm = DCCP_SOCKET__NODE_BIND; 3856 break; 3857 3858 default: 3859 node_perm = RAWIP_SOCKET__NODE_BIND; 3860 break; 3861 } 3862 3863 err = sel_netnode_sid(addrp, family, &sid); 3864 if (err) 3865 goto out; 3866 3867 COMMON_AUDIT_DATA_INIT(&ad, NET); 3868 ad.u.net.sport = htons(snum); 3869 ad.u.net.family = family; 3870 3871 if (family == PF_INET) 3872 ad.u.net.v4info.saddr = addr4->sin_addr.s_addr; 3873 else 3874 ad.u.net.v6info.saddr = addr6->sin6_addr; 3875 3876 err = avc_has_perm(sksec->sid, sid, 3877 sksec->sclass, node_perm, &ad); 3878 if (err) 3879 goto out; 3880 } 3881 out: 3882 return err; 3883 } 3884 3885 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen) 3886 { 3887 struct sock *sk = sock->sk; 3888 struct sk_security_struct *sksec = sk->sk_security; 3889 int err; 3890 3891 err = sock_has_perm(current, sk, SOCKET__CONNECT); 3892 if (err) 3893 return err; 3894 3895 /* 3896 * If a TCP or DCCP socket, check name_connect permission for the port. 3897 */ 3898 if (sksec->sclass == SECCLASS_TCP_SOCKET || 3899 sksec->sclass == SECCLASS_DCCP_SOCKET) { 3900 struct common_audit_data ad; 3901 struct sockaddr_in *addr4 = NULL; 3902 struct sockaddr_in6 *addr6 = NULL; 3903 unsigned short snum; 3904 u32 sid, perm; 3905 3906 if (sk->sk_family == PF_INET) { 3907 addr4 = (struct sockaddr_in *)address; 3908 if (addrlen < sizeof(struct sockaddr_in)) 3909 return -EINVAL; 3910 snum = ntohs(addr4->sin_port); 3911 } else { 3912 addr6 = (struct sockaddr_in6 *)address; 3913 if (addrlen < SIN6_LEN_RFC2133) 3914 return -EINVAL; 3915 snum = ntohs(addr6->sin6_port); 3916 } 3917 3918 err = sel_netport_sid(sk->sk_protocol, snum, &sid); 3919 if (err) 3920 goto out; 3921 3922 perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ? 3923 TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT; 3924 3925 COMMON_AUDIT_DATA_INIT(&ad, NET); 3926 ad.u.net.dport = htons(snum); 3927 ad.u.net.family = sk->sk_family; 3928 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad); 3929 if (err) 3930 goto out; 3931 } 3932 3933 err = selinux_netlbl_socket_connect(sk, address); 3934 3935 out: 3936 return err; 3937 } 3938 3939 static int selinux_socket_listen(struct socket *sock, int backlog) 3940 { 3941 return sock_has_perm(current, sock->sk, SOCKET__LISTEN); 3942 } 3943 3944 static int selinux_socket_accept(struct socket *sock, struct socket *newsock) 3945 { 3946 int err; 3947 struct inode_security_struct *isec; 3948 struct inode_security_struct *newisec; 3949 3950 err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT); 3951 if (err) 3952 return err; 3953 3954 newisec = SOCK_INODE(newsock)->i_security; 3955 3956 isec = SOCK_INODE(sock)->i_security; 3957 newisec->sclass = isec->sclass; 3958 newisec->sid = isec->sid; 3959 newisec->initialized = 1; 3960 3961 return 0; 3962 } 3963 3964 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg, 3965 int size) 3966 { 3967 return sock_has_perm(current, sock->sk, SOCKET__WRITE); 3968 } 3969 3970 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg, 3971 int size, int flags) 3972 { 3973 return sock_has_perm(current, sock->sk, SOCKET__READ); 3974 } 3975 3976 static int selinux_socket_getsockname(struct socket *sock) 3977 { 3978 return sock_has_perm(current, sock->sk, SOCKET__GETATTR); 3979 } 3980 3981 static int selinux_socket_getpeername(struct socket *sock) 3982 { 3983 return sock_has_perm(current, sock->sk, SOCKET__GETATTR); 3984 } 3985 3986 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname) 3987 { 3988 int err; 3989 3990 err = sock_has_perm(current, sock->sk, SOCKET__SETOPT); 3991 if (err) 3992 return err; 3993 3994 return selinux_netlbl_socket_setsockopt(sock, level, optname); 3995 } 3996 3997 static int selinux_socket_getsockopt(struct socket *sock, int level, 3998 int optname) 3999 { 4000 return sock_has_perm(current, sock->sk, SOCKET__GETOPT); 4001 } 4002 4003 static int selinux_socket_shutdown(struct socket *sock, int how) 4004 { 4005 return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN); 4006 } 4007 4008 static int selinux_socket_unix_stream_connect(struct sock *sock, 4009 struct sock *other, 4010 struct sock *newsk) 4011 { 4012 struct sk_security_struct *sksec_sock = sock->sk_security; 4013 struct sk_security_struct *sksec_other = other->sk_security; 4014 struct sk_security_struct *sksec_new = newsk->sk_security; 4015 struct common_audit_data ad; 4016 int err; 4017 4018 COMMON_AUDIT_DATA_INIT(&ad, NET); 4019 ad.u.net.sk = other; 4020 4021 err = avc_has_perm(sksec_sock->sid, sksec_other->sid, 4022 sksec_other->sclass, 4023 UNIX_STREAM_SOCKET__CONNECTTO, &ad); 4024 if (err) 4025 return err; 4026 4027 /* server child socket */ 4028 sksec_new->peer_sid = sksec_sock->sid; 4029 err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid, 4030 &sksec_new->sid); 4031 if (err) 4032 return err; 4033 4034 /* connecting socket */ 4035 sksec_sock->peer_sid = sksec_new->sid; 4036 4037 return 0; 4038 } 4039 4040 static int selinux_socket_unix_may_send(struct socket *sock, 4041 struct socket *other) 4042 { 4043 struct sk_security_struct *ssec = sock->sk->sk_security; 4044 struct sk_security_struct *osec = other->sk->sk_security; 4045 struct common_audit_data ad; 4046 4047 COMMON_AUDIT_DATA_INIT(&ad, NET); 4048 ad.u.net.sk = other->sk; 4049 4050 return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO, 4051 &ad); 4052 } 4053 4054 static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family, 4055 u32 peer_sid, 4056 struct common_audit_data *ad) 4057 { 4058 int err; 4059 u32 if_sid; 4060 u32 node_sid; 4061 4062 err = sel_netif_sid(ifindex, &if_sid); 4063 if (err) 4064 return err; 4065 err = avc_has_perm(peer_sid, if_sid, 4066 SECCLASS_NETIF, NETIF__INGRESS, ad); 4067 if (err) 4068 return err; 4069 4070 err = sel_netnode_sid(addrp, family, &node_sid); 4071 if (err) 4072 return err; 4073 return avc_has_perm(peer_sid, node_sid, 4074 SECCLASS_NODE, NODE__RECVFROM, ad); 4075 } 4076 4077 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, 4078 u16 family) 4079 { 4080 int err = 0; 4081 struct sk_security_struct *sksec = sk->sk_security; 4082 u32 sk_sid = sksec->sid; 4083 struct common_audit_data ad; 4084 char *addrp; 4085 4086 COMMON_AUDIT_DATA_INIT(&ad, NET); 4087 ad.u.net.netif = skb->skb_iif; 4088 ad.u.net.family = family; 4089 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); 4090 if (err) 4091 return err; 4092 4093 if (selinux_secmark_enabled()) { 4094 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, 4095 PACKET__RECV, &ad); 4096 if (err) 4097 return err; 4098 } 4099 4100 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad); 4101 if (err) 4102 return err; 4103 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad); 4104 4105 return err; 4106 } 4107 4108 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 4109 { 4110 int err; 4111 struct sk_security_struct *sksec = sk->sk_security; 4112 u16 family = sk->sk_family; 4113 u32 sk_sid = sksec->sid; 4114 struct common_audit_data ad; 4115 char *addrp; 4116 u8 secmark_active; 4117 u8 peerlbl_active; 4118 4119 if (family != PF_INET && family != PF_INET6) 4120 return 0; 4121 4122 /* Handle mapped IPv4 packets arriving via IPv6 sockets */ 4123 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4124 family = PF_INET; 4125 4126 /* If any sort of compatibility mode is enabled then handoff processing 4127 * to the selinux_sock_rcv_skb_compat() function to deal with the 4128 * special handling. We do this in an attempt to keep this function 4129 * as fast and as clean as possible. */ 4130 if (!selinux_policycap_netpeer) 4131 return selinux_sock_rcv_skb_compat(sk, skb, family); 4132 4133 secmark_active = selinux_secmark_enabled(); 4134 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled(); 4135 if (!secmark_active && !peerlbl_active) 4136 return 0; 4137 4138 COMMON_AUDIT_DATA_INIT(&ad, NET); 4139 ad.u.net.netif = skb->skb_iif; 4140 ad.u.net.family = family; 4141 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); 4142 if (err) 4143 return err; 4144 4145 if (peerlbl_active) { 4146 u32 peer_sid; 4147 4148 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid); 4149 if (err) 4150 return err; 4151 err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family, 4152 peer_sid, &ad); 4153 if (err) { 4154 selinux_netlbl_err(skb, err, 0); 4155 return err; 4156 } 4157 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER, 4158 PEER__RECV, &ad); 4159 if (err) 4160 selinux_netlbl_err(skb, err, 0); 4161 } 4162 4163 if (secmark_active) { 4164 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, 4165 PACKET__RECV, &ad); 4166 if (err) 4167 return err; 4168 } 4169 4170 return err; 4171 } 4172 4173 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval, 4174 int __user *optlen, unsigned len) 4175 { 4176 int err = 0; 4177 char *scontext; 4178 u32 scontext_len; 4179 struct sk_security_struct *sksec = sock->sk->sk_security; 4180 u32 peer_sid = SECSID_NULL; 4181 4182 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET || 4183 sksec->sclass == SECCLASS_TCP_SOCKET) 4184 peer_sid = sksec->peer_sid; 4185 if (peer_sid == SECSID_NULL) 4186 return -ENOPROTOOPT; 4187 4188 err = security_sid_to_context(peer_sid, &scontext, &scontext_len); 4189 if (err) 4190 return err; 4191 4192 if (scontext_len > len) { 4193 err = -ERANGE; 4194 goto out_len; 4195 } 4196 4197 if (copy_to_user(optval, scontext, scontext_len)) 4198 err = -EFAULT; 4199 4200 out_len: 4201 if (put_user(scontext_len, optlen)) 4202 err = -EFAULT; 4203 kfree(scontext); 4204 return err; 4205 } 4206 4207 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) 4208 { 4209 u32 peer_secid = SECSID_NULL; 4210 u16 family; 4211 4212 if (skb && skb->protocol == htons(ETH_P_IP)) 4213 family = PF_INET; 4214 else if (skb && skb->protocol == htons(ETH_P_IPV6)) 4215 family = PF_INET6; 4216 else if (sock) 4217 family = sock->sk->sk_family; 4218 else 4219 goto out; 4220 4221 if (sock && family == PF_UNIX) 4222 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid); 4223 else if (skb) 4224 selinux_skb_peerlbl_sid(skb, family, &peer_secid); 4225 4226 out: 4227 *secid = peer_secid; 4228 if (peer_secid == SECSID_NULL) 4229 return -EINVAL; 4230 return 0; 4231 } 4232 4233 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority) 4234 { 4235 struct sk_security_struct *sksec; 4236 4237 sksec = kzalloc(sizeof(*sksec), priority); 4238 if (!sksec) 4239 return -ENOMEM; 4240 4241 sksec->peer_sid = SECINITSID_UNLABELED; 4242 sksec->sid = SECINITSID_UNLABELED; 4243 selinux_netlbl_sk_security_reset(sksec); 4244 sk->sk_security = sksec; 4245 4246 return 0; 4247 } 4248 4249 static void selinux_sk_free_security(struct sock *sk) 4250 { 4251 struct sk_security_struct *sksec = sk->sk_security; 4252 4253 sk->sk_security = NULL; 4254 selinux_netlbl_sk_security_free(sksec); 4255 kfree(sksec); 4256 } 4257 4258 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk) 4259 { 4260 struct sk_security_struct *sksec = sk->sk_security; 4261 struct sk_security_struct *newsksec = newsk->sk_security; 4262 4263 newsksec->sid = sksec->sid; 4264 newsksec->peer_sid = sksec->peer_sid; 4265 newsksec->sclass = sksec->sclass; 4266 4267 selinux_netlbl_sk_security_reset(newsksec); 4268 } 4269 4270 static void selinux_sk_getsecid(struct sock *sk, u32 *secid) 4271 { 4272 if (!sk) 4273 *secid = SECINITSID_ANY_SOCKET; 4274 else { 4275 struct sk_security_struct *sksec = sk->sk_security; 4276 4277 *secid = sksec->sid; 4278 } 4279 } 4280 4281 static void selinux_sock_graft(struct sock *sk, struct socket *parent) 4282 { 4283 struct inode_security_struct *isec = SOCK_INODE(parent)->i_security; 4284 struct sk_security_struct *sksec = sk->sk_security; 4285 4286 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 || 4287 sk->sk_family == PF_UNIX) 4288 isec->sid = sksec->sid; 4289 sksec->sclass = isec->sclass; 4290 } 4291 4292 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, 4293 struct request_sock *req) 4294 { 4295 struct sk_security_struct *sksec = sk->sk_security; 4296 int err; 4297 u16 family = sk->sk_family; 4298 u32 newsid; 4299 u32 peersid; 4300 4301 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 4302 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4303 family = PF_INET; 4304 4305 err = selinux_skb_peerlbl_sid(skb, family, &peersid); 4306 if (err) 4307 return err; 4308 if (peersid == SECSID_NULL) { 4309 req->secid = sksec->sid; 4310 req->peer_secid = SECSID_NULL; 4311 } else { 4312 err = security_sid_mls_copy(sksec->sid, peersid, &newsid); 4313 if (err) 4314 return err; 4315 req->secid = newsid; 4316 req->peer_secid = peersid; 4317 } 4318 4319 return selinux_netlbl_inet_conn_request(req, family); 4320 } 4321 4322 static void selinux_inet_csk_clone(struct sock *newsk, 4323 const struct request_sock *req) 4324 { 4325 struct sk_security_struct *newsksec = newsk->sk_security; 4326 4327 newsksec->sid = req->secid; 4328 newsksec->peer_sid = req->peer_secid; 4329 /* NOTE: Ideally, we should also get the isec->sid for the 4330 new socket in sync, but we don't have the isec available yet. 4331 So we will wait until sock_graft to do it, by which 4332 time it will have been created and available. */ 4333 4334 /* We don't need to take any sort of lock here as we are the only 4335 * thread with access to newsksec */ 4336 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family); 4337 } 4338 4339 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) 4340 { 4341 u16 family = sk->sk_family; 4342 struct sk_security_struct *sksec = sk->sk_security; 4343 4344 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 4345 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4346 family = PF_INET; 4347 4348 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid); 4349 } 4350 4351 static int selinux_secmark_relabel_packet(u32 sid) 4352 { 4353 const struct task_security_struct *__tsec; 4354 u32 tsid; 4355 4356 __tsec = current_security(); 4357 tsid = __tsec->sid; 4358 4359 return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL); 4360 } 4361 4362 static void selinux_secmark_refcount_inc(void) 4363 { 4364 atomic_inc(&selinux_secmark_refcount); 4365 } 4366 4367 static void selinux_secmark_refcount_dec(void) 4368 { 4369 atomic_dec(&selinux_secmark_refcount); 4370 } 4371 4372 static void selinux_req_classify_flow(const struct request_sock *req, 4373 struct flowi *fl) 4374 { 4375 fl->flowi_secid = req->secid; 4376 } 4377 4378 static int selinux_tun_dev_create(void) 4379 { 4380 u32 sid = current_sid(); 4381 4382 /* we aren't taking into account the "sockcreate" SID since the socket 4383 * that is being created here is not a socket in the traditional sense, 4384 * instead it is a private sock, accessible only to the kernel, and 4385 * representing a wide range of network traffic spanning multiple 4386 * connections unlike traditional sockets - check the TUN driver to 4387 * get a better understanding of why this socket is special */ 4388 4389 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE, 4390 NULL); 4391 } 4392 4393 static void selinux_tun_dev_post_create(struct sock *sk) 4394 { 4395 struct sk_security_struct *sksec = sk->sk_security; 4396 4397 /* we don't currently perform any NetLabel based labeling here and it 4398 * isn't clear that we would want to do so anyway; while we could apply 4399 * labeling without the support of the TUN user the resulting labeled 4400 * traffic from the other end of the connection would almost certainly 4401 * cause confusion to the TUN user that had no idea network labeling 4402 * protocols were being used */ 4403 4404 /* see the comments in selinux_tun_dev_create() about why we don't use 4405 * the sockcreate SID here */ 4406 4407 sksec->sid = current_sid(); 4408 sksec->sclass = SECCLASS_TUN_SOCKET; 4409 } 4410 4411 static int selinux_tun_dev_attach(struct sock *sk) 4412 { 4413 struct sk_security_struct *sksec = sk->sk_security; 4414 u32 sid = current_sid(); 4415 int err; 4416 4417 err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET, 4418 TUN_SOCKET__RELABELFROM, NULL); 4419 if (err) 4420 return err; 4421 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, 4422 TUN_SOCKET__RELABELTO, NULL); 4423 if (err) 4424 return err; 4425 4426 sksec->sid = sid; 4427 4428 return 0; 4429 } 4430 4431 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb) 4432 { 4433 int err = 0; 4434 u32 perm; 4435 struct nlmsghdr *nlh; 4436 struct sk_security_struct *sksec = sk->sk_security; 4437 4438 if (skb->len < NLMSG_SPACE(0)) { 4439 err = -EINVAL; 4440 goto out; 4441 } 4442 nlh = nlmsg_hdr(skb); 4443 4444 err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm); 4445 if (err) { 4446 if (err == -EINVAL) { 4447 audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR, 4448 "SELinux: unrecognized netlink message" 4449 " type=%hu for sclass=%hu\n", 4450 nlh->nlmsg_type, sksec->sclass); 4451 if (!selinux_enforcing || security_get_allow_unknown()) 4452 err = 0; 4453 } 4454 4455 /* Ignore */ 4456 if (err == -ENOENT) 4457 err = 0; 4458 goto out; 4459 } 4460 4461 err = sock_has_perm(current, sk, perm); 4462 out: 4463 return err; 4464 } 4465 4466 #ifdef CONFIG_NETFILTER 4467 4468 static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, 4469 u16 family) 4470 { 4471 int err; 4472 char *addrp; 4473 u32 peer_sid; 4474 struct common_audit_data ad; 4475 u8 secmark_active; 4476 u8 netlbl_active; 4477 u8 peerlbl_active; 4478 4479 if (!selinux_policycap_netpeer) 4480 return NF_ACCEPT; 4481 4482 secmark_active = selinux_secmark_enabled(); 4483 netlbl_active = netlbl_enabled(); 4484 peerlbl_active = netlbl_active || selinux_xfrm_enabled(); 4485 if (!secmark_active && !peerlbl_active) 4486 return NF_ACCEPT; 4487 4488 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0) 4489 return NF_DROP; 4490 4491 COMMON_AUDIT_DATA_INIT(&ad, NET); 4492 ad.u.net.netif = ifindex; 4493 ad.u.net.family = family; 4494 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0) 4495 return NF_DROP; 4496 4497 if (peerlbl_active) { 4498 err = selinux_inet_sys_rcv_skb(ifindex, addrp, family, 4499 peer_sid, &ad); 4500 if (err) { 4501 selinux_netlbl_err(skb, err, 1); 4502 return NF_DROP; 4503 } 4504 } 4505 4506 if (secmark_active) 4507 if (avc_has_perm(peer_sid, skb->secmark, 4508 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad)) 4509 return NF_DROP; 4510 4511 if (netlbl_active) 4512 /* we do this in the FORWARD path and not the POST_ROUTING 4513 * path because we want to make sure we apply the necessary 4514 * labeling before IPsec is applied so we can leverage AH 4515 * protection */ 4516 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0) 4517 return NF_DROP; 4518 4519 return NF_ACCEPT; 4520 } 4521 4522 static unsigned int selinux_ipv4_forward(unsigned int hooknum, 4523 struct sk_buff *skb, 4524 const struct net_device *in, 4525 const struct net_device *out, 4526 int (*okfn)(struct sk_buff *)) 4527 { 4528 return selinux_ip_forward(skb, in->ifindex, PF_INET); 4529 } 4530 4531 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 4532 static unsigned int selinux_ipv6_forward(unsigned int hooknum, 4533 struct sk_buff *skb, 4534 const struct net_device *in, 4535 const struct net_device *out, 4536 int (*okfn)(struct sk_buff *)) 4537 { 4538 return selinux_ip_forward(skb, in->ifindex, PF_INET6); 4539 } 4540 #endif /* IPV6 */ 4541 4542 static unsigned int selinux_ip_output(struct sk_buff *skb, 4543 u16 family) 4544 { 4545 u32 sid; 4546 4547 if (!netlbl_enabled()) 4548 return NF_ACCEPT; 4549 4550 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path 4551 * because we want to make sure we apply the necessary labeling 4552 * before IPsec is applied so we can leverage AH protection */ 4553 if (skb->sk) { 4554 struct sk_security_struct *sksec = skb->sk->sk_security; 4555 sid = sksec->sid; 4556 } else 4557 sid = SECINITSID_KERNEL; 4558 if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0) 4559 return NF_DROP; 4560 4561 return NF_ACCEPT; 4562 } 4563 4564 static unsigned int selinux_ipv4_output(unsigned int hooknum, 4565 struct sk_buff *skb, 4566 const struct net_device *in, 4567 const struct net_device *out, 4568 int (*okfn)(struct sk_buff *)) 4569 { 4570 return selinux_ip_output(skb, PF_INET); 4571 } 4572 4573 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb, 4574 int ifindex, 4575 u16 family) 4576 { 4577 struct sock *sk = skb->sk; 4578 struct sk_security_struct *sksec; 4579 struct common_audit_data ad; 4580 char *addrp; 4581 u8 proto; 4582 4583 if (sk == NULL) 4584 return NF_ACCEPT; 4585 sksec = sk->sk_security; 4586 4587 COMMON_AUDIT_DATA_INIT(&ad, NET); 4588 ad.u.net.netif = ifindex; 4589 ad.u.net.family = family; 4590 if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto)) 4591 return NF_DROP; 4592 4593 if (selinux_secmark_enabled()) 4594 if (avc_has_perm(sksec->sid, skb->secmark, 4595 SECCLASS_PACKET, PACKET__SEND, &ad)) 4596 return NF_DROP_ERR(-ECONNREFUSED); 4597 4598 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto)) 4599 return NF_DROP_ERR(-ECONNREFUSED); 4600 4601 return NF_ACCEPT; 4602 } 4603 4604 static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, 4605 u16 family) 4606 { 4607 u32 secmark_perm; 4608 u32 peer_sid; 4609 struct sock *sk; 4610 struct common_audit_data ad; 4611 char *addrp; 4612 u8 secmark_active; 4613 u8 peerlbl_active; 4614 4615 /* If any sort of compatibility mode is enabled then handoff processing 4616 * to the selinux_ip_postroute_compat() function to deal with the 4617 * special handling. We do this in an attempt to keep this function 4618 * as fast and as clean as possible. */ 4619 if (!selinux_policycap_netpeer) 4620 return selinux_ip_postroute_compat(skb, ifindex, family); 4621 #ifdef CONFIG_XFRM 4622 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec 4623 * packet transformation so allow the packet to pass without any checks 4624 * since we'll have another chance to perform access control checks 4625 * when the packet is on it's final way out. 4626 * NOTE: there appear to be some IPv6 multicast cases where skb->dst 4627 * is NULL, in this case go ahead and apply access control. */ 4628 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL) 4629 return NF_ACCEPT; 4630 #endif 4631 secmark_active = selinux_secmark_enabled(); 4632 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled(); 4633 if (!secmark_active && !peerlbl_active) 4634 return NF_ACCEPT; 4635 4636 /* if the packet is being forwarded then get the peer label from the 4637 * packet itself; otherwise check to see if it is from a local 4638 * application or the kernel, if from an application get the peer label 4639 * from the sending socket, otherwise use the kernel's sid */ 4640 sk = skb->sk; 4641 if (sk == NULL) { 4642 if (skb->skb_iif) { 4643 secmark_perm = PACKET__FORWARD_OUT; 4644 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid)) 4645 return NF_DROP; 4646 } else { 4647 secmark_perm = PACKET__SEND; 4648 peer_sid = SECINITSID_KERNEL; 4649 } 4650 } else { 4651 struct sk_security_struct *sksec = sk->sk_security; 4652 peer_sid = sksec->sid; 4653 secmark_perm = PACKET__SEND; 4654 } 4655 4656 COMMON_AUDIT_DATA_INIT(&ad, NET); 4657 ad.u.net.netif = ifindex; 4658 ad.u.net.family = family; 4659 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL)) 4660 return NF_DROP; 4661 4662 if (secmark_active) 4663 if (avc_has_perm(peer_sid, skb->secmark, 4664 SECCLASS_PACKET, secmark_perm, &ad)) 4665 return NF_DROP_ERR(-ECONNREFUSED); 4666 4667 if (peerlbl_active) { 4668 u32 if_sid; 4669 u32 node_sid; 4670 4671 if (sel_netif_sid(ifindex, &if_sid)) 4672 return NF_DROP; 4673 if (avc_has_perm(peer_sid, if_sid, 4674 SECCLASS_NETIF, NETIF__EGRESS, &ad)) 4675 return NF_DROP_ERR(-ECONNREFUSED); 4676 4677 if (sel_netnode_sid(addrp, family, &node_sid)) 4678 return NF_DROP; 4679 if (avc_has_perm(peer_sid, node_sid, 4680 SECCLASS_NODE, NODE__SENDTO, &ad)) 4681 return NF_DROP_ERR(-ECONNREFUSED); 4682 } 4683 4684 return NF_ACCEPT; 4685 } 4686 4687 static unsigned int selinux_ipv4_postroute(unsigned int hooknum, 4688 struct sk_buff *skb, 4689 const struct net_device *in, 4690 const struct net_device *out, 4691 int (*okfn)(struct sk_buff *)) 4692 { 4693 return selinux_ip_postroute(skb, out->ifindex, PF_INET); 4694 } 4695 4696 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 4697 static unsigned int selinux_ipv6_postroute(unsigned int hooknum, 4698 struct sk_buff *skb, 4699 const struct net_device *in, 4700 const struct net_device *out, 4701 int (*okfn)(struct sk_buff *)) 4702 { 4703 return selinux_ip_postroute(skb, out->ifindex, PF_INET6); 4704 } 4705 #endif /* IPV6 */ 4706 4707 #endif /* CONFIG_NETFILTER */ 4708 4709 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb) 4710 { 4711 int err; 4712 4713 err = cap_netlink_send(sk, skb); 4714 if (err) 4715 return err; 4716 4717 return selinux_nlmsg_perm(sk, skb); 4718 } 4719 4720 static int ipc_alloc_security(struct task_struct *task, 4721 struct kern_ipc_perm *perm, 4722 u16 sclass) 4723 { 4724 struct ipc_security_struct *isec; 4725 u32 sid; 4726 4727 isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL); 4728 if (!isec) 4729 return -ENOMEM; 4730 4731 sid = task_sid(task); 4732 isec->sclass = sclass; 4733 isec->sid = sid; 4734 perm->security = isec; 4735 4736 return 0; 4737 } 4738 4739 static void ipc_free_security(struct kern_ipc_perm *perm) 4740 { 4741 struct ipc_security_struct *isec = perm->security; 4742 perm->security = NULL; 4743 kfree(isec); 4744 } 4745 4746 static int msg_msg_alloc_security(struct msg_msg *msg) 4747 { 4748 struct msg_security_struct *msec; 4749 4750 msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL); 4751 if (!msec) 4752 return -ENOMEM; 4753 4754 msec->sid = SECINITSID_UNLABELED; 4755 msg->security = msec; 4756 4757 return 0; 4758 } 4759 4760 static void msg_msg_free_security(struct msg_msg *msg) 4761 { 4762 struct msg_security_struct *msec = msg->security; 4763 4764 msg->security = NULL; 4765 kfree(msec); 4766 } 4767 4768 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms, 4769 u32 perms) 4770 { 4771 struct ipc_security_struct *isec; 4772 struct common_audit_data ad; 4773 u32 sid = current_sid(); 4774 4775 isec = ipc_perms->security; 4776 4777 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4778 ad.u.ipc_id = ipc_perms->key; 4779 4780 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad); 4781 } 4782 4783 static int selinux_msg_msg_alloc_security(struct msg_msg *msg) 4784 { 4785 return msg_msg_alloc_security(msg); 4786 } 4787 4788 static void selinux_msg_msg_free_security(struct msg_msg *msg) 4789 { 4790 msg_msg_free_security(msg); 4791 } 4792 4793 /* message queue security operations */ 4794 static int selinux_msg_queue_alloc_security(struct msg_queue *msq) 4795 { 4796 struct ipc_security_struct *isec; 4797 struct common_audit_data ad; 4798 u32 sid = current_sid(); 4799 int rc; 4800 4801 rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ); 4802 if (rc) 4803 return rc; 4804 4805 isec = msq->q_perm.security; 4806 4807 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4808 ad.u.ipc_id = msq->q_perm.key; 4809 4810 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 4811 MSGQ__CREATE, &ad); 4812 if (rc) { 4813 ipc_free_security(&msq->q_perm); 4814 return rc; 4815 } 4816 return 0; 4817 } 4818 4819 static void selinux_msg_queue_free_security(struct msg_queue *msq) 4820 { 4821 ipc_free_security(&msq->q_perm); 4822 } 4823 4824 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg) 4825 { 4826 struct ipc_security_struct *isec; 4827 struct common_audit_data ad; 4828 u32 sid = current_sid(); 4829 4830 isec = msq->q_perm.security; 4831 4832 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4833 ad.u.ipc_id = msq->q_perm.key; 4834 4835 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 4836 MSGQ__ASSOCIATE, &ad); 4837 } 4838 4839 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd) 4840 { 4841 int err; 4842 int perms; 4843 4844 switch (cmd) { 4845 case IPC_INFO: 4846 case MSG_INFO: 4847 /* No specific object, just general system-wide information. */ 4848 return task_has_system(current, SYSTEM__IPC_INFO); 4849 case IPC_STAT: 4850 case MSG_STAT: 4851 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE; 4852 break; 4853 case IPC_SET: 4854 perms = MSGQ__SETATTR; 4855 break; 4856 case IPC_RMID: 4857 perms = MSGQ__DESTROY; 4858 break; 4859 default: 4860 return 0; 4861 } 4862 4863 err = ipc_has_perm(&msq->q_perm, perms); 4864 return err; 4865 } 4866 4867 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg) 4868 { 4869 struct ipc_security_struct *isec; 4870 struct msg_security_struct *msec; 4871 struct common_audit_data ad; 4872 u32 sid = current_sid(); 4873 int rc; 4874 4875 isec = msq->q_perm.security; 4876 msec = msg->security; 4877 4878 /* 4879 * First time through, need to assign label to the message 4880 */ 4881 if (msec->sid == SECINITSID_UNLABELED) { 4882 /* 4883 * Compute new sid based on current process and 4884 * message queue this message will be stored in 4885 */ 4886 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG, 4887 NULL, &msec->sid); 4888 if (rc) 4889 return rc; 4890 } 4891 4892 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4893 ad.u.ipc_id = msq->q_perm.key; 4894 4895 /* Can this process write to the queue? */ 4896 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 4897 MSGQ__WRITE, &ad); 4898 if (!rc) 4899 /* Can this process send the message */ 4900 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG, 4901 MSG__SEND, &ad); 4902 if (!rc) 4903 /* Can the message be put in the queue? */ 4904 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ, 4905 MSGQ__ENQUEUE, &ad); 4906 4907 return rc; 4908 } 4909 4910 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, 4911 struct task_struct *target, 4912 long type, int mode) 4913 { 4914 struct ipc_security_struct *isec; 4915 struct msg_security_struct *msec; 4916 struct common_audit_data ad; 4917 u32 sid = task_sid(target); 4918 int rc; 4919 4920 isec = msq->q_perm.security; 4921 msec = msg->security; 4922 4923 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4924 ad.u.ipc_id = msq->q_perm.key; 4925 4926 rc = avc_has_perm(sid, isec->sid, 4927 SECCLASS_MSGQ, MSGQ__READ, &ad); 4928 if (!rc) 4929 rc = avc_has_perm(sid, msec->sid, 4930 SECCLASS_MSG, MSG__RECEIVE, &ad); 4931 return rc; 4932 } 4933 4934 /* Shared Memory security operations */ 4935 static int selinux_shm_alloc_security(struct shmid_kernel *shp) 4936 { 4937 struct ipc_security_struct *isec; 4938 struct common_audit_data ad; 4939 u32 sid = current_sid(); 4940 int rc; 4941 4942 rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM); 4943 if (rc) 4944 return rc; 4945 4946 isec = shp->shm_perm.security; 4947 4948 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4949 ad.u.ipc_id = shp->shm_perm.key; 4950 4951 rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM, 4952 SHM__CREATE, &ad); 4953 if (rc) { 4954 ipc_free_security(&shp->shm_perm); 4955 return rc; 4956 } 4957 return 0; 4958 } 4959 4960 static void selinux_shm_free_security(struct shmid_kernel *shp) 4961 { 4962 ipc_free_security(&shp->shm_perm); 4963 } 4964 4965 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg) 4966 { 4967 struct ipc_security_struct *isec; 4968 struct common_audit_data ad; 4969 u32 sid = current_sid(); 4970 4971 isec = shp->shm_perm.security; 4972 4973 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4974 ad.u.ipc_id = shp->shm_perm.key; 4975 4976 return avc_has_perm(sid, isec->sid, SECCLASS_SHM, 4977 SHM__ASSOCIATE, &ad); 4978 } 4979 4980 /* Note, at this point, shp is locked down */ 4981 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd) 4982 { 4983 int perms; 4984 int err; 4985 4986 switch (cmd) { 4987 case IPC_INFO: 4988 case SHM_INFO: 4989 /* No specific object, just general system-wide information. */ 4990 return task_has_system(current, SYSTEM__IPC_INFO); 4991 case IPC_STAT: 4992 case SHM_STAT: 4993 perms = SHM__GETATTR | SHM__ASSOCIATE; 4994 break; 4995 case IPC_SET: 4996 perms = SHM__SETATTR; 4997 break; 4998 case SHM_LOCK: 4999 case SHM_UNLOCK: 5000 perms = SHM__LOCK; 5001 break; 5002 case IPC_RMID: 5003 perms = SHM__DESTROY; 5004 break; 5005 default: 5006 return 0; 5007 } 5008 5009 err = ipc_has_perm(&shp->shm_perm, perms); 5010 return err; 5011 } 5012 5013 static int selinux_shm_shmat(struct shmid_kernel *shp, 5014 char __user *shmaddr, int shmflg) 5015 { 5016 u32 perms; 5017 5018 if (shmflg & SHM_RDONLY) 5019 perms = SHM__READ; 5020 else 5021 perms = SHM__READ | SHM__WRITE; 5022 5023 return ipc_has_perm(&shp->shm_perm, perms); 5024 } 5025 5026 /* Semaphore security operations */ 5027 static int selinux_sem_alloc_security(struct sem_array *sma) 5028 { 5029 struct ipc_security_struct *isec; 5030 struct common_audit_data ad; 5031 u32 sid = current_sid(); 5032 int rc; 5033 5034 rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM); 5035 if (rc) 5036 return rc; 5037 5038 isec = sma->sem_perm.security; 5039 5040 COMMON_AUDIT_DATA_INIT(&ad, IPC); 5041 ad.u.ipc_id = sma->sem_perm.key; 5042 5043 rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM, 5044 SEM__CREATE, &ad); 5045 if (rc) { 5046 ipc_free_security(&sma->sem_perm); 5047 return rc; 5048 } 5049 return 0; 5050 } 5051 5052 static void selinux_sem_free_security(struct sem_array *sma) 5053 { 5054 ipc_free_security(&sma->sem_perm); 5055 } 5056 5057 static int selinux_sem_associate(struct sem_array *sma, int semflg) 5058 { 5059 struct ipc_security_struct *isec; 5060 struct common_audit_data ad; 5061 u32 sid = current_sid(); 5062 5063 isec = sma->sem_perm.security; 5064 5065 COMMON_AUDIT_DATA_INIT(&ad, IPC); 5066 ad.u.ipc_id = sma->sem_perm.key; 5067 5068 return avc_has_perm(sid, isec->sid, SECCLASS_SEM, 5069 SEM__ASSOCIATE, &ad); 5070 } 5071 5072 /* Note, at this point, sma is locked down */ 5073 static int selinux_sem_semctl(struct sem_array *sma, int cmd) 5074 { 5075 int err; 5076 u32 perms; 5077 5078 switch (cmd) { 5079 case IPC_INFO: 5080 case SEM_INFO: 5081 /* No specific object, just general system-wide information. */ 5082 return task_has_system(current, SYSTEM__IPC_INFO); 5083 case GETPID: 5084 case GETNCNT: 5085 case GETZCNT: 5086 perms = SEM__GETATTR; 5087 break; 5088 case GETVAL: 5089 case GETALL: 5090 perms = SEM__READ; 5091 break; 5092 case SETVAL: 5093 case SETALL: 5094 perms = SEM__WRITE; 5095 break; 5096 case IPC_RMID: 5097 perms = SEM__DESTROY; 5098 break; 5099 case IPC_SET: 5100 perms = SEM__SETATTR; 5101 break; 5102 case IPC_STAT: 5103 case SEM_STAT: 5104 perms = SEM__GETATTR | SEM__ASSOCIATE; 5105 break; 5106 default: 5107 return 0; 5108 } 5109 5110 err = ipc_has_perm(&sma->sem_perm, perms); 5111 return err; 5112 } 5113 5114 static int selinux_sem_semop(struct sem_array *sma, 5115 struct sembuf *sops, unsigned nsops, int alter) 5116 { 5117 u32 perms; 5118 5119 if (alter) 5120 perms = SEM__READ | SEM__WRITE; 5121 else 5122 perms = SEM__READ; 5123 5124 return ipc_has_perm(&sma->sem_perm, perms); 5125 } 5126 5127 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag) 5128 { 5129 u32 av = 0; 5130 5131 av = 0; 5132 if (flag & S_IRUGO) 5133 av |= IPC__UNIX_READ; 5134 if (flag & S_IWUGO) 5135 av |= IPC__UNIX_WRITE; 5136 5137 if (av == 0) 5138 return 0; 5139 5140 return ipc_has_perm(ipcp, av); 5141 } 5142 5143 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid) 5144 { 5145 struct ipc_security_struct *isec = ipcp->security; 5146 *secid = isec->sid; 5147 } 5148 5149 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode) 5150 { 5151 if (inode) 5152 inode_doinit_with_dentry(inode, dentry); 5153 } 5154 5155 static int selinux_getprocattr(struct task_struct *p, 5156 char *name, char **value) 5157 { 5158 const struct task_security_struct *__tsec; 5159 u32 sid; 5160 int error; 5161 unsigned len; 5162 5163 if (current != p) { 5164 error = current_has_perm(p, PROCESS__GETATTR); 5165 if (error) 5166 return error; 5167 } 5168 5169 rcu_read_lock(); 5170 __tsec = __task_cred(p)->security; 5171 5172 if (!strcmp(name, "current")) 5173 sid = __tsec->sid; 5174 else if (!strcmp(name, "prev")) 5175 sid = __tsec->osid; 5176 else if (!strcmp(name, "exec")) 5177 sid = __tsec->exec_sid; 5178 else if (!strcmp(name, "fscreate")) 5179 sid = __tsec->create_sid; 5180 else if (!strcmp(name, "keycreate")) 5181 sid = __tsec->keycreate_sid; 5182 else if (!strcmp(name, "sockcreate")) 5183 sid = __tsec->sockcreate_sid; 5184 else 5185 goto invalid; 5186 rcu_read_unlock(); 5187 5188 if (!sid) 5189 return 0; 5190 5191 error = security_sid_to_context(sid, value, &len); 5192 if (error) 5193 return error; 5194 return len; 5195 5196 invalid: 5197 rcu_read_unlock(); 5198 return -EINVAL; 5199 } 5200 5201 static int selinux_setprocattr(struct task_struct *p, 5202 char *name, void *value, size_t size) 5203 { 5204 struct task_security_struct *tsec; 5205 struct task_struct *tracer; 5206 struct cred *new; 5207 u32 sid = 0, ptsid; 5208 int error; 5209 char *str = value; 5210 5211 if (current != p) { 5212 /* SELinux only allows a process to change its own 5213 security attributes. */ 5214 return -EACCES; 5215 } 5216 5217 /* 5218 * Basic control over ability to set these attributes at all. 5219 * current == p, but we'll pass them separately in case the 5220 * above restriction is ever removed. 5221 */ 5222 if (!strcmp(name, "exec")) 5223 error = current_has_perm(p, PROCESS__SETEXEC); 5224 else if (!strcmp(name, "fscreate")) 5225 error = current_has_perm(p, PROCESS__SETFSCREATE); 5226 else if (!strcmp(name, "keycreate")) 5227 error = current_has_perm(p, PROCESS__SETKEYCREATE); 5228 else if (!strcmp(name, "sockcreate")) 5229 error = current_has_perm(p, PROCESS__SETSOCKCREATE); 5230 else if (!strcmp(name, "current")) 5231 error = current_has_perm(p, PROCESS__SETCURRENT); 5232 else 5233 error = -EINVAL; 5234 if (error) 5235 return error; 5236 5237 /* Obtain a SID for the context, if one was specified. */ 5238 if (size && str[1] && str[1] != '\n') { 5239 if (str[size-1] == '\n') { 5240 str[size-1] = 0; 5241 size--; 5242 } 5243 error = security_context_to_sid(value, size, &sid); 5244 if (error == -EINVAL && !strcmp(name, "fscreate")) { 5245 if (!capable(CAP_MAC_ADMIN)) 5246 return error; 5247 error = security_context_to_sid_force(value, size, 5248 &sid); 5249 } 5250 if (error) 5251 return error; 5252 } 5253 5254 new = prepare_creds(); 5255 if (!new) 5256 return -ENOMEM; 5257 5258 /* Permission checking based on the specified context is 5259 performed during the actual operation (execve, 5260 open/mkdir/...), when we know the full context of the 5261 operation. See selinux_bprm_set_creds for the execve 5262 checks and may_create for the file creation checks. The 5263 operation will then fail if the context is not permitted. */ 5264 tsec = new->security; 5265 if (!strcmp(name, "exec")) { 5266 tsec->exec_sid = sid; 5267 } else if (!strcmp(name, "fscreate")) { 5268 tsec->create_sid = sid; 5269 } else if (!strcmp(name, "keycreate")) { 5270 error = may_create_key(sid, p); 5271 if (error) 5272 goto abort_change; 5273 tsec->keycreate_sid = sid; 5274 } else if (!strcmp(name, "sockcreate")) { 5275 tsec->sockcreate_sid = sid; 5276 } else if (!strcmp(name, "current")) { 5277 error = -EINVAL; 5278 if (sid == 0) 5279 goto abort_change; 5280 5281 /* Only allow single threaded processes to change context */ 5282 error = -EPERM; 5283 if (!current_is_single_threaded()) { 5284 error = security_bounded_transition(tsec->sid, sid); 5285 if (error) 5286 goto abort_change; 5287 } 5288 5289 /* Check permissions for the transition. */ 5290 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS, 5291 PROCESS__DYNTRANSITION, NULL); 5292 if (error) 5293 goto abort_change; 5294 5295 /* Check for ptracing, and update the task SID if ok. 5296 Otherwise, leave SID unchanged and fail. */ 5297 ptsid = 0; 5298 task_lock(p); 5299 tracer = ptrace_parent(p); 5300 if (tracer) 5301 ptsid = task_sid(tracer); 5302 task_unlock(p); 5303 5304 if (tracer) { 5305 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS, 5306 PROCESS__PTRACE, NULL); 5307 if (error) 5308 goto abort_change; 5309 } 5310 5311 tsec->sid = sid; 5312 } else { 5313 error = -EINVAL; 5314 goto abort_change; 5315 } 5316 5317 commit_creds(new); 5318 return size; 5319 5320 abort_change: 5321 abort_creds(new); 5322 return error; 5323 } 5324 5325 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) 5326 { 5327 return security_sid_to_context(secid, secdata, seclen); 5328 } 5329 5330 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) 5331 { 5332 return security_context_to_sid(secdata, seclen, secid); 5333 } 5334 5335 static void selinux_release_secctx(char *secdata, u32 seclen) 5336 { 5337 kfree(secdata); 5338 } 5339 5340 /* 5341 * called with inode->i_mutex locked 5342 */ 5343 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) 5344 { 5345 return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0); 5346 } 5347 5348 /* 5349 * called with inode->i_mutex locked 5350 */ 5351 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) 5352 { 5353 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0); 5354 } 5355 5356 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) 5357 { 5358 int len = 0; 5359 len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX, 5360 ctx, true); 5361 if (len < 0) 5362 return len; 5363 *ctxlen = len; 5364 return 0; 5365 } 5366 #ifdef CONFIG_KEYS 5367 5368 static int selinux_key_alloc(struct key *k, const struct cred *cred, 5369 unsigned long flags) 5370 { 5371 const struct task_security_struct *tsec; 5372 struct key_security_struct *ksec; 5373 5374 ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL); 5375 if (!ksec) 5376 return -ENOMEM; 5377 5378 tsec = cred->security; 5379 if (tsec->keycreate_sid) 5380 ksec->sid = tsec->keycreate_sid; 5381 else 5382 ksec->sid = tsec->sid; 5383 5384 k->security = ksec; 5385 return 0; 5386 } 5387 5388 static void selinux_key_free(struct key *k) 5389 { 5390 struct key_security_struct *ksec = k->security; 5391 5392 k->security = NULL; 5393 kfree(ksec); 5394 } 5395 5396 static int selinux_key_permission(key_ref_t key_ref, 5397 const struct cred *cred, 5398 key_perm_t perm) 5399 { 5400 struct key *key; 5401 struct key_security_struct *ksec; 5402 u32 sid; 5403 5404 /* if no specific permissions are requested, we skip the 5405 permission check. No serious, additional covert channels 5406 appear to be created. */ 5407 if (perm == 0) 5408 return 0; 5409 5410 sid = cred_sid(cred); 5411 5412 key = key_ref_to_ptr(key_ref); 5413 ksec = key->security; 5414 5415 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL); 5416 } 5417 5418 static int selinux_key_getsecurity(struct key *key, char **_buffer) 5419 { 5420 struct key_security_struct *ksec = key->security; 5421 char *context = NULL; 5422 unsigned len; 5423 int rc; 5424 5425 rc = security_sid_to_context(ksec->sid, &context, &len); 5426 if (!rc) 5427 rc = len; 5428 *_buffer = context; 5429 return rc; 5430 } 5431 5432 #endif 5433 5434 static struct security_operations selinux_ops = { 5435 .name = "selinux", 5436 5437 .ptrace_access_check = selinux_ptrace_access_check, 5438 .ptrace_traceme = selinux_ptrace_traceme, 5439 .capget = selinux_capget, 5440 .capset = selinux_capset, 5441 .capable = selinux_capable, 5442 .quotactl = selinux_quotactl, 5443 .quota_on = selinux_quota_on, 5444 .syslog = selinux_syslog, 5445 .vm_enough_memory = selinux_vm_enough_memory, 5446 5447 .netlink_send = selinux_netlink_send, 5448 5449 .bprm_set_creds = selinux_bprm_set_creds, 5450 .bprm_committing_creds = selinux_bprm_committing_creds, 5451 .bprm_committed_creds = selinux_bprm_committed_creds, 5452 .bprm_secureexec = selinux_bprm_secureexec, 5453 5454 .sb_alloc_security = selinux_sb_alloc_security, 5455 .sb_free_security = selinux_sb_free_security, 5456 .sb_copy_data = selinux_sb_copy_data, 5457 .sb_remount = selinux_sb_remount, 5458 .sb_kern_mount = selinux_sb_kern_mount, 5459 .sb_show_options = selinux_sb_show_options, 5460 .sb_statfs = selinux_sb_statfs, 5461 .sb_mount = selinux_mount, 5462 .sb_umount = selinux_umount, 5463 .sb_set_mnt_opts = selinux_set_mnt_opts, 5464 .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts, 5465 .sb_parse_opts_str = selinux_parse_opts_str, 5466 5467 5468 .inode_alloc_security = selinux_inode_alloc_security, 5469 .inode_free_security = selinux_inode_free_security, 5470 .inode_init_security = selinux_inode_init_security, 5471 .inode_create = selinux_inode_create, 5472 .inode_link = selinux_inode_link, 5473 .inode_unlink = selinux_inode_unlink, 5474 .inode_symlink = selinux_inode_symlink, 5475 .inode_mkdir = selinux_inode_mkdir, 5476 .inode_rmdir = selinux_inode_rmdir, 5477 .inode_mknod = selinux_inode_mknod, 5478 .inode_rename = selinux_inode_rename, 5479 .inode_readlink = selinux_inode_readlink, 5480 .inode_follow_link = selinux_inode_follow_link, 5481 .inode_permission = selinux_inode_permission, 5482 .inode_setattr = selinux_inode_setattr, 5483 .inode_getattr = selinux_inode_getattr, 5484 .inode_setxattr = selinux_inode_setxattr, 5485 .inode_post_setxattr = selinux_inode_post_setxattr, 5486 .inode_getxattr = selinux_inode_getxattr, 5487 .inode_listxattr = selinux_inode_listxattr, 5488 .inode_removexattr = selinux_inode_removexattr, 5489 .inode_getsecurity = selinux_inode_getsecurity, 5490 .inode_setsecurity = selinux_inode_setsecurity, 5491 .inode_listsecurity = selinux_inode_listsecurity, 5492 .inode_getsecid = selinux_inode_getsecid, 5493 5494 .file_permission = selinux_file_permission, 5495 .file_alloc_security = selinux_file_alloc_security, 5496 .file_free_security = selinux_file_free_security, 5497 .file_ioctl = selinux_file_ioctl, 5498 .file_mmap = selinux_file_mmap, 5499 .file_mprotect = selinux_file_mprotect, 5500 .file_lock = selinux_file_lock, 5501 .file_fcntl = selinux_file_fcntl, 5502 .file_set_fowner = selinux_file_set_fowner, 5503 .file_send_sigiotask = selinux_file_send_sigiotask, 5504 .file_receive = selinux_file_receive, 5505 5506 .dentry_open = selinux_dentry_open, 5507 5508 .task_create = selinux_task_create, 5509 .cred_alloc_blank = selinux_cred_alloc_blank, 5510 .cred_free = selinux_cred_free, 5511 .cred_prepare = selinux_cred_prepare, 5512 .cred_transfer = selinux_cred_transfer, 5513 .kernel_act_as = selinux_kernel_act_as, 5514 .kernel_create_files_as = selinux_kernel_create_files_as, 5515 .kernel_module_request = selinux_kernel_module_request, 5516 .task_setpgid = selinux_task_setpgid, 5517 .task_getpgid = selinux_task_getpgid, 5518 .task_getsid = selinux_task_getsid, 5519 .task_getsecid = selinux_task_getsecid, 5520 .task_setnice = selinux_task_setnice, 5521 .task_setioprio = selinux_task_setioprio, 5522 .task_getioprio = selinux_task_getioprio, 5523 .task_setrlimit = selinux_task_setrlimit, 5524 .task_setscheduler = selinux_task_setscheduler, 5525 .task_getscheduler = selinux_task_getscheduler, 5526 .task_movememory = selinux_task_movememory, 5527 .task_kill = selinux_task_kill, 5528 .task_wait = selinux_task_wait, 5529 .task_to_inode = selinux_task_to_inode, 5530 5531 .ipc_permission = selinux_ipc_permission, 5532 .ipc_getsecid = selinux_ipc_getsecid, 5533 5534 .msg_msg_alloc_security = selinux_msg_msg_alloc_security, 5535 .msg_msg_free_security = selinux_msg_msg_free_security, 5536 5537 .msg_queue_alloc_security = selinux_msg_queue_alloc_security, 5538 .msg_queue_free_security = selinux_msg_queue_free_security, 5539 .msg_queue_associate = selinux_msg_queue_associate, 5540 .msg_queue_msgctl = selinux_msg_queue_msgctl, 5541 .msg_queue_msgsnd = selinux_msg_queue_msgsnd, 5542 .msg_queue_msgrcv = selinux_msg_queue_msgrcv, 5543 5544 .shm_alloc_security = selinux_shm_alloc_security, 5545 .shm_free_security = selinux_shm_free_security, 5546 .shm_associate = selinux_shm_associate, 5547 .shm_shmctl = selinux_shm_shmctl, 5548 .shm_shmat = selinux_shm_shmat, 5549 5550 .sem_alloc_security = selinux_sem_alloc_security, 5551 .sem_free_security = selinux_sem_free_security, 5552 .sem_associate = selinux_sem_associate, 5553 .sem_semctl = selinux_sem_semctl, 5554 .sem_semop = selinux_sem_semop, 5555 5556 .d_instantiate = selinux_d_instantiate, 5557 5558 .getprocattr = selinux_getprocattr, 5559 .setprocattr = selinux_setprocattr, 5560 5561 .secid_to_secctx = selinux_secid_to_secctx, 5562 .secctx_to_secid = selinux_secctx_to_secid, 5563 .release_secctx = selinux_release_secctx, 5564 .inode_notifysecctx = selinux_inode_notifysecctx, 5565 .inode_setsecctx = selinux_inode_setsecctx, 5566 .inode_getsecctx = selinux_inode_getsecctx, 5567 5568 .unix_stream_connect = selinux_socket_unix_stream_connect, 5569 .unix_may_send = selinux_socket_unix_may_send, 5570 5571 .socket_create = selinux_socket_create, 5572 .socket_post_create = selinux_socket_post_create, 5573 .socket_bind = selinux_socket_bind, 5574 .socket_connect = selinux_socket_connect, 5575 .socket_listen = selinux_socket_listen, 5576 .socket_accept = selinux_socket_accept, 5577 .socket_sendmsg = selinux_socket_sendmsg, 5578 .socket_recvmsg = selinux_socket_recvmsg, 5579 .socket_getsockname = selinux_socket_getsockname, 5580 .socket_getpeername = selinux_socket_getpeername, 5581 .socket_getsockopt = selinux_socket_getsockopt, 5582 .socket_setsockopt = selinux_socket_setsockopt, 5583 .socket_shutdown = selinux_socket_shutdown, 5584 .socket_sock_rcv_skb = selinux_socket_sock_rcv_skb, 5585 .socket_getpeersec_stream = selinux_socket_getpeersec_stream, 5586 .socket_getpeersec_dgram = selinux_socket_getpeersec_dgram, 5587 .sk_alloc_security = selinux_sk_alloc_security, 5588 .sk_free_security = selinux_sk_free_security, 5589 .sk_clone_security = selinux_sk_clone_security, 5590 .sk_getsecid = selinux_sk_getsecid, 5591 .sock_graft = selinux_sock_graft, 5592 .inet_conn_request = selinux_inet_conn_request, 5593 .inet_csk_clone = selinux_inet_csk_clone, 5594 .inet_conn_established = selinux_inet_conn_established, 5595 .secmark_relabel_packet = selinux_secmark_relabel_packet, 5596 .secmark_refcount_inc = selinux_secmark_refcount_inc, 5597 .secmark_refcount_dec = selinux_secmark_refcount_dec, 5598 .req_classify_flow = selinux_req_classify_flow, 5599 .tun_dev_create = selinux_tun_dev_create, 5600 .tun_dev_post_create = selinux_tun_dev_post_create, 5601 .tun_dev_attach = selinux_tun_dev_attach, 5602 5603 #ifdef CONFIG_SECURITY_NETWORK_XFRM 5604 .xfrm_policy_alloc_security = selinux_xfrm_policy_alloc, 5605 .xfrm_policy_clone_security = selinux_xfrm_policy_clone, 5606 .xfrm_policy_free_security = selinux_xfrm_policy_free, 5607 .xfrm_policy_delete_security = selinux_xfrm_policy_delete, 5608 .xfrm_state_alloc_security = selinux_xfrm_state_alloc, 5609 .xfrm_state_free_security = selinux_xfrm_state_free, 5610 .xfrm_state_delete_security = selinux_xfrm_state_delete, 5611 .xfrm_policy_lookup = selinux_xfrm_policy_lookup, 5612 .xfrm_state_pol_flow_match = selinux_xfrm_state_pol_flow_match, 5613 .xfrm_decode_session = selinux_xfrm_decode_session, 5614 #endif 5615 5616 #ifdef CONFIG_KEYS 5617 .key_alloc = selinux_key_alloc, 5618 .key_free = selinux_key_free, 5619 .key_permission = selinux_key_permission, 5620 .key_getsecurity = selinux_key_getsecurity, 5621 #endif 5622 5623 #ifdef CONFIG_AUDIT 5624 .audit_rule_init = selinux_audit_rule_init, 5625 .audit_rule_known = selinux_audit_rule_known, 5626 .audit_rule_match = selinux_audit_rule_match, 5627 .audit_rule_free = selinux_audit_rule_free, 5628 #endif 5629 }; 5630 5631 static __init int selinux_init(void) 5632 { 5633 if (!security_module_enable(&selinux_ops)) { 5634 selinux_enabled = 0; 5635 return 0; 5636 } 5637 5638 if (!selinux_enabled) { 5639 printk(KERN_INFO "SELinux: Disabled at boot.\n"); 5640 return 0; 5641 } 5642 5643 printk(KERN_INFO "SELinux: Initializing.\n"); 5644 5645 /* Set the security state for the initial task. */ 5646 cred_init_security(); 5647 5648 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC); 5649 5650 sel_inode_cache = kmem_cache_create("selinux_inode_security", 5651 sizeof(struct inode_security_struct), 5652 0, SLAB_PANIC, NULL); 5653 avc_init(); 5654 5655 if (register_security(&selinux_ops)) 5656 panic("SELinux: Unable to register with kernel.\n"); 5657 5658 if (selinux_enforcing) 5659 printk(KERN_DEBUG "SELinux: Starting in enforcing mode\n"); 5660 else 5661 printk(KERN_DEBUG "SELinux: Starting in permissive mode\n"); 5662 5663 return 0; 5664 } 5665 5666 static void delayed_superblock_init(struct super_block *sb, void *unused) 5667 { 5668 superblock_doinit(sb, NULL); 5669 } 5670 5671 void selinux_complete_init(void) 5672 { 5673 printk(KERN_DEBUG "SELinux: Completing initialization.\n"); 5674 5675 /* Set up any superblocks initialized prior to the policy load. */ 5676 printk(KERN_DEBUG "SELinux: Setting up existing superblocks.\n"); 5677 iterate_supers(delayed_superblock_init, NULL); 5678 } 5679 5680 /* SELinux requires early initialization in order to label 5681 all processes and objects when they are created. */ 5682 security_initcall(selinux_init); 5683 5684 #if defined(CONFIG_NETFILTER) 5685 5686 static struct nf_hook_ops selinux_ipv4_ops[] = { 5687 { 5688 .hook = selinux_ipv4_postroute, 5689 .owner = THIS_MODULE, 5690 .pf = PF_INET, 5691 .hooknum = NF_INET_POST_ROUTING, 5692 .priority = NF_IP_PRI_SELINUX_LAST, 5693 }, 5694 { 5695 .hook = selinux_ipv4_forward, 5696 .owner = THIS_MODULE, 5697 .pf = PF_INET, 5698 .hooknum = NF_INET_FORWARD, 5699 .priority = NF_IP_PRI_SELINUX_FIRST, 5700 }, 5701 { 5702 .hook = selinux_ipv4_output, 5703 .owner = THIS_MODULE, 5704 .pf = PF_INET, 5705 .hooknum = NF_INET_LOCAL_OUT, 5706 .priority = NF_IP_PRI_SELINUX_FIRST, 5707 } 5708 }; 5709 5710 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 5711 5712 static struct nf_hook_ops selinux_ipv6_ops[] = { 5713 { 5714 .hook = selinux_ipv6_postroute, 5715 .owner = THIS_MODULE, 5716 .pf = PF_INET6, 5717 .hooknum = NF_INET_POST_ROUTING, 5718 .priority = NF_IP6_PRI_SELINUX_LAST, 5719 }, 5720 { 5721 .hook = selinux_ipv6_forward, 5722 .owner = THIS_MODULE, 5723 .pf = PF_INET6, 5724 .hooknum = NF_INET_FORWARD, 5725 .priority = NF_IP6_PRI_SELINUX_FIRST, 5726 } 5727 }; 5728 5729 #endif /* IPV6 */ 5730 5731 static int __init selinux_nf_ip_init(void) 5732 { 5733 int err = 0; 5734 5735 if (!selinux_enabled) 5736 goto out; 5737 5738 printk(KERN_DEBUG "SELinux: Registering netfilter hooks\n"); 5739 5740 err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops)); 5741 if (err) 5742 panic("SELinux: nf_register_hooks for IPv4: error %d\n", err); 5743 5744 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 5745 err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops)); 5746 if (err) 5747 panic("SELinux: nf_register_hooks for IPv6: error %d\n", err); 5748 #endif /* IPV6 */ 5749 5750 out: 5751 return err; 5752 } 5753 5754 __initcall(selinux_nf_ip_init); 5755 5756 #ifdef CONFIG_SECURITY_SELINUX_DISABLE 5757 static void selinux_nf_ip_exit(void) 5758 { 5759 printk(KERN_DEBUG "SELinux: Unregistering netfilter hooks\n"); 5760 5761 nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops)); 5762 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 5763 nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops)); 5764 #endif /* IPV6 */ 5765 } 5766 #endif 5767 5768 #else /* CONFIG_NETFILTER */ 5769 5770 #ifdef CONFIG_SECURITY_SELINUX_DISABLE 5771 #define selinux_nf_ip_exit() 5772 #endif 5773 5774 #endif /* CONFIG_NETFILTER */ 5775 5776 #ifdef CONFIG_SECURITY_SELINUX_DISABLE 5777 static int selinux_disabled; 5778 5779 int selinux_disable(void) 5780 { 5781 if (ss_initialized) { 5782 /* Not permitted after initial policy load. */ 5783 return -EINVAL; 5784 } 5785 5786 if (selinux_disabled) { 5787 /* Only do this once. */ 5788 return -EINVAL; 5789 } 5790 5791 printk(KERN_INFO "SELinux: Disabled at runtime.\n"); 5792 5793 selinux_disabled = 1; 5794 selinux_enabled = 0; 5795 5796 reset_security_ops(); 5797 5798 /* Try to destroy the avc node cache */ 5799 avc_disable(); 5800 5801 /* Unregister netfilter hooks. */ 5802 selinux_nf_ip_exit(); 5803 5804 /* Unregister selinuxfs. */ 5805 exit_sel_fs(); 5806 5807 return 0; 5808 } 5809 #endif 5810