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.moore@hp.com> 18 * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd. 19 * Yuichi Nakamura <ynakam@hitachisoft.jp> 20 * 21 * This program is free software; you can redistribute it and/or modify 22 * it under the terms of the GNU General Public License version 2, 23 * as published by the Free Software Foundation. 24 */ 25 26#include <linux/init.h> 27#include <linux/kernel.h> 28#include <linux/tracehook.h> 29#include <linux/errno.h> 30#include <linux/sched.h> 31#include <linux/security.h> 32#include <linux/xattr.h> 33#include <linux/capability.h> 34#include <linux/unistd.h> 35#include <linux/mm.h> 36#include <linux/mman.h> 37#include <linux/slab.h> 38#include <linux/pagemap.h> 39#include <linux/swap.h> 40#include <linux/spinlock.h> 41#include <linux/syscalls.h> 42#include <linux/file.h> 43#include <linux/fdtable.h> 44#include <linux/namei.h> 45#include <linux/mount.h> 46#include <linux/proc_fs.h> 47#include <linux/netfilter_ipv4.h> 48#include <linux/netfilter_ipv6.h> 49#include <linux/tty.h> 50#include <net/icmp.h> 51#include <net/ip.h> /* for local_port_range[] */ 52#include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */ 53#include <net/net_namespace.h> 54#include <net/netlabel.h> 55#include <linux/uaccess.h> 56#include <asm/ioctls.h> 57#include <asm/atomic.h> 58#include <linux/bitops.h> 59#include <linux/interrupt.h> 60#include <linux/netdevice.h> /* for network interface checks */ 61#include <linux/netlink.h> 62#include <linux/tcp.h> 63#include <linux/udp.h> 64#include <linux/dccp.h> 65#include <linux/quota.h> 66#include <linux/un.h> /* for Unix socket types */ 67#include <net/af_unix.h> /* for Unix socket types */ 68#include <linux/parser.h> 69#include <linux/nfs_mount.h> 70#include <net/ipv6.h> 71#include <linux/hugetlb.h> 72#include <linux/personality.h> 73#include <linux/sysctl.h> 74#include <linux/audit.h> 75#include <linux/string.h> 76#include <linux/selinux.h> 77#include <linux/mutex.h> 78#include <linux/posix-timers.h> 79#include <linux/syslog.h> 80 81#include "avc.h" 82#include "objsec.h" 83#include "netif.h" 84#include "netnode.h" 85#include "netport.h" 86#include "xfrm.h" 87#include "netlabel.h" 88#include "audit.h" 89 90#define NUM_SEL_MNT_OPTS 5 91 92extern int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm); 93extern struct security_operations *security_ops; 94 95/* SECMARK reference count */ 96atomic_t selinux_secmark_refcount = ATOMIC_INIT(0); 97 98#ifdef CONFIG_SECURITY_SELINUX_DEVELOP 99int selinux_enforcing; 100 101static int __init enforcing_setup(char *str) 102{ 103 unsigned long enforcing; 104 if (!strict_strtoul(str, 0, &enforcing)) 105 selinux_enforcing = enforcing ? 1 : 0; 106 return 1; 107} 108__setup("enforcing=", enforcing_setup); 109#endif 110 111#ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM 112int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE; 113 114static int __init selinux_enabled_setup(char *str) 115{ 116 unsigned long enabled; 117 if (!strict_strtoul(str, 0, &enabled)) 118 selinux_enabled = enabled ? 1 : 0; 119 return 1; 120} 121__setup("selinux=", selinux_enabled_setup); 122#else 123int selinux_enabled = 1; 124#endif 125 126static struct kmem_cache *sel_inode_cache; 127 128/** 129 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled 130 * 131 * Description: 132 * This function checks the SECMARK reference counter to see if any SECMARK 133 * targets are currently configured, if the reference counter is greater than 134 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is 135 * enabled, false (0) if SECMARK is disabled. 136 * 137 */ 138static int selinux_secmark_enabled(void) 139{ 140 return (atomic_read(&selinux_secmark_refcount) > 0); 141} 142 143/* 144 * initialise the security for the init task 145 */ 146static void cred_init_security(void) 147{ 148 struct cred *cred = (struct cred *) current->real_cred; 149 struct task_security_struct *tsec; 150 151 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL); 152 if (!tsec) 153 panic("SELinux: Failed to initialize initial task.\n"); 154 155 tsec->osid = tsec->sid = SECINITSID_KERNEL; 156 cred->security = tsec; 157} 158 159/* 160 * get the security ID of a set of credentials 161 */ 162static inline u32 cred_sid(const struct cred *cred) 163{ 164 const struct task_security_struct *tsec; 165 166 tsec = cred->security; 167 return tsec->sid; 168} 169 170/* 171 * get the objective security ID of a task 172 */ 173static inline u32 task_sid(const struct task_struct *task) 174{ 175 u32 sid; 176 177 rcu_read_lock(); 178 sid = cred_sid(__task_cred(task)); 179 rcu_read_unlock(); 180 return sid; 181} 182 183/* 184 * get the subjective security ID of the current task 185 */ 186static inline u32 current_sid(void) 187{ 188 const struct task_security_struct *tsec = current_security(); 189 190 return tsec->sid; 191} 192 193/* Allocate and free functions for each kind of security blob. */ 194 195static int inode_alloc_security(struct inode *inode) 196{ 197 struct inode_security_struct *isec; 198 u32 sid = current_sid(); 199 200 isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS); 201 if (!isec) 202 return -ENOMEM; 203 204 mutex_init(&isec->lock); 205 INIT_LIST_HEAD(&isec->list); 206 isec->inode = inode; 207 isec->sid = SECINITSID_UNLABELED; 208 isec->sclass = SECCLASS_FILE; 209 isec->task_sid = sid; 210 inode->i_security = isec; 211 212 return 0; 213} 214 215static void inode_free_security(struct inode *inode) 216{ 217 struct inode_security_struct *isec = inode->i_security; 218 struct superblock_security_struct *sbsec = inode->i_sb->s_security; 219 220 spin_lock(&sbsec->isec_lock); 221 if (!list_empty(&isec->list)) 222 list_del_init(&isec->list); 223 spin_unlock(&sbsec->isec_lock); 224 225 inode->i_security = NULL; 226 kmem_cache_free(sel_inode_cache, isec); 227} 228 229static int file_alloc_security(struct file *file) 230{ 231 struct file_security_struct *fsec; 232 u32 sid = current_sid(); 233 234 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL); 235 if (!fsec) 236 return -ENOMEM; 237 238 fsec->sid = sid; 239 fsec->fown_sid = sid; 240 file->f_security = fsec; 241 242 return 0; 243} 244 245static void file_free_security(struct file *file) 246{ 247 struct file_security_struct *fsec = file->f_security; 248 file->f_security = NULL; 249 kfree(fsec); 250} 251 252static int superblock_alloc_security(struct super_block *sb) 253{ 254 struct superblock_security_struct *sbsec; 255 256 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); 257 if (!sbsec) 258 return -ENOMEM; 259 260 mutex_init(&sbsec->lock); 261 INIT_LIST_HEAD(&sbsec->isec_head); 262 spin_lock_init(&sbsec->isec_lock); 263 sbsec->sb = sb; 264 sbsec->sid = SECINITSID_UNLABELED; 265 sbsec->def_sid = SECINITSID_FILE; 266 sbsec->mntpoint_sid = SECINITSID_UNLABELED; 267 sb->s_security = sbsec; 268 269 return 0; 270} 271 272static void superblock_free_security(struct super_block *sb) 273{ 274 struct superblock_security_struct *sbsec = sb->s_security; 275 sb->s_security = NULL; 276 kfree(sbsec); 277} 278 279/* The security server must be initialized before 280 any labeling or access decisions can be provided. */ 281extern int ss_initialized; 282 283/* The file system's label must be initialized prior to use. */ 284 285static const char *labeling_behaviors[6] = { 286 "uses xattr", 287 "uses transition SIDs", 288 "uses task SIDs", 289 "uses genfs_contexts", 290 "not configured for labeling", 291 "uses mountpoint labeling", 292}; 293 294static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); 295 296static inline int inode_doinit(struct inode *inode) 297{ 298 return inode_doinit_with_dentry(inode, NULL); 299} 300 301enum { 302 Opt_error = -1, 303 Opt_context = 1, 304 Opt_fscontext = 2, 305 Opt_defcontext = 3, 306 Opt_rootcontext = 4, 307 Opt_labelsupport = 5, 308}; 309 310static const match_table_t tokens = { 311 {Opt_context, CONTEXT_STR "%s"}, 312 {Opt_fscontext, FSCONTEXT_STR "%s"}, 313 {Opt_defcontext, DEFCONTEXT_STR "%s"}, 314 {Opt_rootcontext, ROOTCONTEXT_STR "%s"}, 315 {Opt_labelsupport, LABELSUPP_STR}, 316 {Opt_error, NULL}, 317}; 318 319#define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" 320 321static int may_context_mount_sb_relabel(u32 sid, 322 struct superblock_security_struct *sbsec, 323 const struct cred *cred) 324{ 325 const struct task_security_struct *tsec = cred->security; 326 int rc; 327 328 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, 329 FILESYSTEM__RELABELFROM, NULL); 330 if (rc) 331 return rc; 332 333 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM, 334 FILESYSTEM__RELABELTO, NULL); 335 return rc; 336} 337 338static int may_context_mount_inode_relabel(u32 sid, 339 struct superblock_security_struct *sbsec, 340 const struct cred *cred) 341{ 342 const struct task_security_struct *tsec = cred->security; 343 int rc; 344 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, 345 FILESYSTEM__RELABELFROM, NULL); 346 if (rc) 347 return rc; 348 349 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, 350 FILESYSTEM__ASSOCIATE, NULL); 351 return rc; 352} 353 354static int sb_finish_set_opts(struct super_block *sb) 355{ 356 struct superblock_security_struct *sbsec = sb->s_security; 357 struct dentry *root = sb->s_root; 358 struct inode *root_inode = root->d_inode; 359 int rc = 0; 360 361 if (sbsec->behavior == SECURITY_FS_USE_XATTR) { 362 /* Make sure that the xattr handler exists and that no 363 error other than -ENODATA is returned by getxattr on 364 the root directory. -ENODATA is ok, as this may be 365 the first boot of the SELinux kernel before we have 366 assigned xattr values to the filesystem. */ 367 if (!root_inode->i_op->getxattr) { 368 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no " 369 "xattr support\n", sb->s_id, sb->s_type->name); 370 rc = -EOPNOTSUPP; 371 goto out; 372 } 373 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0); 374 if (rc < 0 && rc != -ENODATA) { 375 if (rc == -EOPNOTSUPP) 376 printk(KERN_WARNING "SELinux: (dev %s, type " 377 "%s) has no security xattr handler\n", 378 sb->s_id, sb->s_type->name); 379 else 380 printk(KERN_WARNING "SELinux: (dev %s, type " 381 "%s) getxattr errno %d\n", sb->s_id, 382 sb->s_type->name, -rc); 383 goto out; 384 } 385 } 386 387 sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP); 388 389 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) 390 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n", 391 sb->s_id, sb->s_type->name); 392 else 393 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n", 394 sb->s_id, sb->s_type->name, 395 labeling_behaviors[sbsec->behavior-1]); 396 397 if (sbsec->behavior == SECURITY_FS_USE_GENFS || 398 sbsec->behavior == SECURITY_FS_USE_MNTPOINT || 399 sbsec->behavior == SECURITY_FS_USE_NONE || 400 sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) 401 sbsec->flags &= ~SE_SBLABELSUPP; 402 403 /* Special handling for sysfs. Is genfs but also has setxattr handler*/ 404 if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0) 405 sbsec->flags |= SE_SBLABELSUPP; 406 407 /* Initialize the root inode. */ 408 rc = inode_doinit_with_dentry(root_inode, root); 409 410 /* Initialize any other inodes associated with the superblock, e.g. 411 inodes created prior to initial policy load or inodes created 412 during get_sb by a pseudo filesystem that directly 413 populates itself. */ 414 spin_lock(&sbsec->isec_lock); 415next_inode: 416 if (!list_empty(&sbsec->isec_head)) { 417 struct inode_security_struct *isec = 418 list_entry(sbsec->isec_head.next, 419 struct inode_security_struct, list); 420 struct inode *inode = isec->inode; 421 spin_unlock(&sbsec->isec_lock); 422 inode = igrab(inode); 423 if (inode) { 424 if (!IS_PRIVATE(inode)) 425 inode_doinit(inode); 426 iput(inode); 427 } 428 spin_lock(&sbsec->isec_lock); 429 list_del_init(&isec->list); 430 goto next_inode; 431 } 432 spin_unlock(&sbsec->isec_lock); 433out: 434 return rc; 435} 436 437/* 438 * This function should allow an FS to ask what it's mount security 439 * options were so it can use those later for submounts, displaying 440 * mount options, or whatever. 441 */ 442static int selinux_get_mnt_opts(const struct super_block *sb, 443 struct security_mnt_opts *opts) 444{ 445 int rc = 0, i; 446 struct superblock_security_struct *sbsec = sb->s_security; 447 char *context = NULL; 448 u32 len; 449 char tmp; 450 451 security_init_mnt_opts(opts); 452 453 if (!(sbsec->flags & SE_SBINITIALIZED)) 454 return -EINVAL; 455 456 if (!ss_initialized) 457 return -EINVAL; 458 459 tmp = sbsec->flags & SE_MNTMASK; 460 /* count the number of mount options for this sb */ 461 for (i = 0; i < 8; i++) { 462 if (tmp & 0x01) 463 opts->num_mnt_opts++; 464 tmp >>= 1; 465 } 466 /* Check if the Label support flag is set */ 467 if (sbsec->flags & SE_SBLABELSUPP) 468 opts->num_mnt_opts++; 469 470 opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC); 471 if (!opts->mnt_opts) { 472 rc = -ENOMEM; 473 goto out_free; 474 } 475 476 opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC); 477 if (!opts->mnt_opts_flags) { 478 rc = -ENOMEM; 479 goto out_free; 480 } 481 482 i = 0; 483 if (sbsec->flags & FSCONTEXT_MNT) { 484 rc = security_sid_to_context(sbsec->sid, &context, &len); 485 if (rc) 486 goto out_free; 487 opts->mnt_opts[i] = context; 488 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT; 489 } 490 if (sbsec->flags & CONTEXT_MNT) { 491 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len); 492 if (rc) 493 goto out_free; 494 opts->mnt_opts[i] = context; 495 opts->mnt_opts_flags[i++] = CONTEXT_MNT; 496 } 497 if (sbsec->flags & DEFCONTEXT_MNT) { 498 rc = security_sid_to_context(sbsec->def_sid, &context, &len); 499 if (rc) 500 goto out_free; 501 opts->mnt_opts[i] = context; 502 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT; 503 } 504 if (sbsec->flags & ROOTCONTEXT_MNT) { 505 struct inode *root = sbsec->sb->s_root->d_inode; 506 struct inode_security_struct *isec = root->i_security; 507 508 rc = security_sid_to_context(isec->sid, &context, &len); 509 if (rc) 510 goto out_free; 511 opts->mnt_opts[i] = context; 512 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT; 513 } 514 if (sbsec->flags & SE_SBLABELSUPP) { 515 opts->mnt_opts[i] = NULL; 516 opts->mnt_opts_flags[i++] = SE_SBLABELSUPP; 517 } 518 519 BUG_ON(i != opts->num_mnt_opts); 520 521 return 0; 522 523out_free: 524 security_free_mnt_opts(opts); 525 return rc; 526} 527 528static int bad_option(struct superblock_security_struct *sbsec, char flag, 529 u32 old_sid, u32 new_sid) 530{ 531 char mnt_flags = sbsec->flags & SE_MNTMASK; 532 533 /* check if the old mount command had the same options */ 534 if (sbsec->flags & SE_SBINITIALIZED) 535 if (!(sbsec->flags & flag) || 536 (old_sid != new_sid)) 537 return 1; 538 539 /* check if we were passed the same options twice, 540 * aka someone passed context=a,context=b 541 */ 542 if (!(sbsec->flags & SE_SBINITIALIZED)) 543 if (mnt_flags & flag) 544 return 1; 545 return 0; 546} 547 548/* 549 * Allow filesystems with binary mount data to explicitly set mount point 550 * labeling information. 551 */ 552static int selinux_set_mnt_opts(struct super_block *sb, 553 struct security_mnt_opts *opts) 554{ 555 const struct cred *cred = current_cred(); 556 int rc = 0, i; 557 struct superblock_security_struct *sbsec = sb->s_security; 558 const char *name = sb->s_type->name; 559 struct inode *inode = sbsec->sb->s_root->d_inode; 560 struct inode_security_struct *root_isec = inode->i_security; 561 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; 562 u32 defcontext_sid = 0; 563 char **mount_options = opts->mnt_opts; 564 int *flags = opts->mnt_opts_flags; 565 int num_opts = opts->num_mnt_opts; 566 567 mutex_lock(&sbsec->lock); 568 569 if (!ss_initialized) { 570 if (!num_opts) { 571 /* Defer initialization until selinux_complete_init, 572 after the initial policy is loaded and the security 573 server is ready to handle calls. */ 574 goto out; 575 } 576 rc = -EINVAL; 577 printk(KERN_WARNING "SELinux: Unable to set superblock options " 578 "before the security server is initialized\n"); 579 goto out; 580 } 581 582 /* 583 * Binary mount data FS will come through this function twice. Once 584 * from an explicit call and once from the generic calls from the vfs. 585 * Since the generic VFS calls will not contain any security mount data 586 * we need to skip the double mount verification. 587 * 588 * This does open a hole in which we will not notice if the first 589 * mount using this sb set explict options and a second mount using 590 * this sb does not set any security options. (The first options 591 * will be used for both mounts) 592 */ 593 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) 594 && (num_opts == 0)) 595 goto out; 596 597 /* 598 * parse the mount options, check if they are valid sids. 599 * also check if someone is trying to mount the same sb more 600 * than once with different security options. 601 */ 602 for (i = 0; i < num_opts; i++) { 603 u32 sid; 604 605 if (flags[i] == SE_SBLABELSUPP) 606 continue; 607 rc = security_context_to_sid(mount_options[i], 608 strlen(mount_options[i]), &sid); 609 if (rc) { 610 printk(KERN_WARNING "SELinux: security_context_to_sid" 611 "(%s) failed for (dev %s, type %s) errno=%d\n", 612 mount_options[i], sb->s_id, name, rc); 613 goto out; 614 } 615 switch (flags[i]) { 616 case FSCONTEXT_MNT: 617 fscontext_sid = sid; 618 619 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, 620 fscontext_sid)) 621 goto out_double_mount; 622 623 sbsec->flags |= FSCONTEXT_MNT; 624 break; 625 case CONTEXT_MNT: 626 context_sid = sid; 627 628 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, 629 context_sid)) 630 goto out_double_mount; 631 632 sbsec->flags |= CONTEXT_MNT; 633 break; 634 case ROOTCONTEXT_MNT: 635 rootcontext_sid = sid; 636 637 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, 638 rootcontext_sid)) 639 goto out_double_mount; 640 641 sbsec->flags |= ROOTCONTEXT_MNT; 642 643 break; 644 case DEFCONTEXT_MNT: 645 defcontext_sid = sid; 646 647 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, 648 defcontext_sid)) 649 goto out_double_mount; 650 651 sbsec->flags |= DEFCONTEXT_MNT; 652 653 break; 654 default: 655 rc = -EINVAL; 656 goto out; 657 } 658 } 659 660 if (sbsec->flags & SE_SBINITIALIZED) { 661 /* previously mounted with options, but not on this attempt? */ 662 if ((sbsec->flags & SE_MNTMASK) && !num_opts) 663 goto out_double_mount; 664 rc = 0; 665 goto out; 666 } 667 668 if (strcmp(sb->s_type->name, "proc") == 0) 669 sbsec->flags |= SE_SBPROC; 670 671 /* Determine the labeling behavior to use for this filesystem type. */ 672 rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid); 673 if (rc) { 674 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n", 675 __func__, sb->s_type->name, rc); 676 goto out; 677 } 678 679 /* sets the context of the superblock for the fs being mounted. */ 680 if (fscontext_sid) { 681 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); 682 if (rc) 683 goto out; 684 685 sbsec->sid = fscontext_sid; 686 } 687 688 /* 689 * Switch to using mount point labeling behavior. 690 * sets the label used on all file below the mountpoint, and will set 691 * the superblock context if not already set. 692 */ 693 if (context_sid) { 694 if (!fscontext_sid) { 695 rc = may_context_mount_sb_relabel(context_sid, sbsec, 696 cred); 697 if (rc) 698 goto out; 699 sbsec->sid = context_sid; 700 } else { 701 rc = may_context_mount_inode_relabel(context_sid, sbsec, 702 cred); 703 if (rc) 704 goto out; 705 } 706 if (!rootcontext_sid) 707 rootcontext_sid = context_sid; 708 709 sbsec->mntpoint_sid = context_sid; 710 sbsec->behavior = SECURITY_FS_USE_MNTPOINT; 711 } 712 713 if (rootcontext_sid) { 714 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, 715 cred); 716 if (rc) 717 goto out; 718 719 root_isec->sid = rootcontext_sid; 720 root_isec->initialized = 1; 721 } 722 723 if (defcontext_sid) { 724 if (sbsec->behavior != SECURITY_FS_USE_XATTR) { 725 rc = -EINVAL; 726 printk(KERN_WARNING "SELinux: defcontext option is " 727 "invalid for this filesystem type\n"); 728 goto out; 729 } 730 731 if (defcontext_sid != sbsec->def_sid) { 732 rc = may_context_mount_inode_relabel(defcontext_sid, 733 sbsec, cred); 734 if (rc) 735 goto out; 736 } 737 738 sbsec->def_sid = defcontext_sid; 739 } 740 741 rc = sb_finish_set_opts(sb); 742out: 743 mutex_unlock(&sbsec->lock); 744 return rc; 745out_double_mount: 746 rc = -EINVAL; 747 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different " 748 "security settings for (dev %s, type %s)\n", sb->s_id, name); 749 goto out; 750} 751 752static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb, 753 struct super_block *newsb) 754{ 755 const struct superblock_security_struct *oldsbsec = oldsb->s_security; 756 struct superblock_security_struct *newsbsec = newsb->s_security; 757 758 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); 759 int set_context = (oldsbsec->flags & CONTEXT_MNT); 760 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT); 761 762 /* 763 * if the parent was able to be mounted it clearly had no special lsm 764 * mount options. thus we can safely deal with this superblock later 765 */ 766 if (!ss_initialized) 767 return; 768 769 /* how can we clone if the old one wasn't set up?? */ 770 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED)); 771 772 /* if fs is reusing a sb, just let its options stand... */ 773 if (newsbsec->flags & SE_SBINITIALIZED) 774 return; 775 776 mutex_lock(&newsbsec->lock); 777 778 newsbsec->flags = oldsbsec->flags; 779 780 newsbsec->sid = oldsbsec->sid; 781 newsbsec->def_sid = oldsbsec->def_sid; 782 newsbsec->behavior = oldsbsec->behavior; 783 784 if (set_context) { 785 u32 sid = oldsbsec->mntpoint_sid; 786 787 if (!set_fscontext) 788 newsbsec->sid = sid; 789 if (!set_rootcontext) { 790 struct inode *newinode = newsb->s_root->d_inode; 791 struct inode_security_struct *newisec = newinode->i_security; 792 newisec->sid = sid; 793 } 794 newsbsec->mntpoint_sid = sid; 795 } 796 if (set_rootcontext) { 797 const struct inode *oldinode = oldsb->s_root->d_inode; 798 const struct inode_security_struct *oldisec = oldinode->i_security; 799 struct inode *newinode = newsb->s_root->d_inode; 800 struct inode_security_struct *newisec = newinode->i_security; 801 802 newisec->sid = oldisec->sid; 803 } 804 805 sb_finish_set_opts(newsb); 806 mutex_unlock(&newsbsec->lock); 807} 808 809static int selinux_parse_opts_str(char *options, 810 struct security_mnt_opts *opts) 811{ 812 char *p; 813 char *context = NULL, *defcontext = NULL; 814 char *fscontext = NULL, *rootcontext = NULL; 815 int rc, num_mnt_opts = 0; 816 817 opts->num_mnt_opts = 0; 818 819 /* Standard string-based options. */ 820 while ((p = strsep(&options, "|")) != NULL) { 821 int token; 822 substring_t args[MAX_OPT_ARGS]; 823 824 if (!*p) 825 continue; 826 827 token = match_token(p, tokens, args); 828 829 switch (token) { 830 case Opt_context: 831 if (context || defcontext) { 832 rc = -EINVAL; 833 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 834 goto out_err; 835 } 836 context = match_strdup(&args[0]); 837 if (!context) { 838 rc = -ENOMEM; 839 goto out_err; 840 } 841 break; 842 843 case Opt_fscontext: 844 if (fscontext) { 845 rc = -EINVAL; 846 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 847 goto out_err; 848 } 849 fscontext = match_strdup(&args[0]); 850 if (!fscontext) { 851 rc = -ENOMEM; 852 goto out_err; 853 } 854 break; 855 856 case Opt_rootcontext: 857 if (rootcontext) { 858 rc = -EINVAL; 859 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 860 goto out_err; 861 } 862 rootcontext = match_strdup(&args[0]); 863 if (!rootcontext) { 864 rc = -ENOMEM; 865 goto out_err; 866 } 867 break; 868 869 case Opt_defcontext: 870 if (context || defcontext) { 871 rc = -EINVAL; 872 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 873 goto out_err; 874 } 875 defcontext = match_strdup(&args[0]); 876 if (!defcontext) { 877 rc = -ENOMEM; 878 goto out_err; 879 } 880 break; 881 case Opt_labelsupport: 882 break; 883 default: 884 rc = -EINVAL; 885 printk(KERN_WARNING "SELinux: unknown mount option\n"); 886 goto out_err; 887 888 } 889 } 890 891 rc = -ENOMEM; 892 opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC); 893 if (!opts->mnt_opts) 894 goto out_err; 895 896 opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC); 897 if (!opts->mnt_opts_flags) { 898 kfree(opts->mnt_opts); 899 goto out_err; 900 } 901 902 if (fscontext) { 903 opts->mnt_opts[num_mnt_opts] = fscontext; 904 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT; 905 } 906 if (context) { 907 opts->mnt_opts[num_mnt_opts] = context; 908 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT; 909 } 910 if (rootcontext) { 911 opts->mnt_opts[num_mnt_opts] = rootcontext; 912 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT; 913 } 914 if (defcontext) { 915 opts->mnt_opts[num_mnt_opts] = defcontext; 916 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT; 917 } 918 919 opts->num_mnt_opts = num_mnt_opts; 920 return 0; 921 922out_err: 923 kfree(context); 924 kfree(defcontext); 925 kfree(fscontext); 926 kfree(rootcontext); 927 return rc; 928} 929/* 930 * string mount options parsing and call set the sbsec 931 */ 932static int superblock_doinit(struct super_block *sb, void *data) 933{ 934 int rc = 0; 935 char *options = data; 936 struct security_mnt_opts opts; 937 938 security_init_mnt_opts(&opts); 939 940 if (!data) 941 goto out; 942 943 BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA); 944 945 rc = selinux_parse_opts_str(options, &opts); 946 if (rc) 947 goto out_err; 948 949out: 950 rc = selinux_set_mnt_opts(sb, &opts); 951 952out_err: 953 security_free_mnt_opts(&opts); 954 return rc; 955} 956 957static void selinux_write_opts(struct seq_file *m, 958 struct security_mnt_opts *opts) 959{ 960 int i; 961 char *prefix; 962 963 for (i = 0; i < opts->num_mnt_opts; i++) { 964 char *has_comma; 965 966 if (opts->mnt_opts[i]) 967 has_comma = strchr(opts->mnt_opts[i], ','); 968 else 969 has_comma = NULL; 970 971 switch (opts->mnt_opts_flags[i]) { 972 case CONTEXT_MNT: 973 prefix = CONTEXT_STR; 974 break; 975 case FSCONTEXT_MNT: 976 prefix = FSCONTEXT_STR; 977 break; 978 case ROOTCONTEXT_MNT: 979 prefix = ROOTCONTEXT_STR; 980 break; 981 case DEFCONTEXT_MNT: 982 prefix = DEFCONTEXT_STR; 983 break; 984 case SE_SBLABELSUPP: 985 seq_putc(m, ','); 986 seq_puts(m, LABELSUPP_STR); 987 continue; 988 default: 989 BUG(); 990 }; 991 /* we need a comma before each option */ 992 seq_putc(m, ','); 993 seq_puts(m, prefix); 994 if (has_comma) 995 seq_putc(m, '\"'); 996 seq_puts(m, opts->mnt_opts[i]); 997 if (has_comma) 998 seq_putc(m, '\"'); 999 } 1000} 1001 1002static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) 1003{ 1004 struct security_mnt_opts opts; 1005 int rc; 1006 1007 rc = selinux_get_mnt_opts(sb, &opts); 1008 if (rc) { 1009 /* before policy load we may get EINVAL, don't show anything */ 1010 if (rc == -EINVAL) 1011 rc = 0; 1012 return rc; 1013 } 1014 1015 selinux_write_opts(m, &opts); 1016 1017 security_free_mnt_opts(&opts); 1018 1019 return rc; 1020} 1021 1022static inline u16 inode_mode_to_security_class(umode_t mode) 1023{ 1024 switch (mode & S_IFMT) { 1025 case S_IFSOCK: 1026 return SECCLASS_SOCK_FILE; 1027 case S_IFLNK: 1028 return SECCLASS_LNK_FILE; 1029 case S_IFREG: 1030 return SECCLASS_FILE; 1031 case S_IFBLK: 1032 return SECCLASS_BLK_FILE; 1033 case S_IFDIR: 1034 return SECCLASS_DIR; 1035 case S_IFCHR: 1036 return SECCLASS_CHR_FILE; 1037 case S_IFIFO: 1038 return SECCLASS_FIFO_FILE; 1039 1040 } 1041 1042 return SECCLASS_FILE; 1043} 1044 1045static inline int default_protocol_stream(int protocol) 1046{ 1047 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP); 1048} 1049 1050static inline int default_protocol_dgram(int protocol) 1051{ 1052 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP); 1053} 1054 1055static inline u16 socket_type_to_security_class(int family, int type, int protocol) 1056{ 1057 switch (family) { 1058 case PF_UNIX: 1059 switch (type) { 1060 case SOCK_STREAM: 1061 case SOCK_SEQPACKET: 1062 return SECCLASS_UNIX_STREAM_SOCKET; 1063 case SOCK_DGRAM: 1064 return SECCLASS_UNIX_DGRAM_SOCKET; 1065 } 1066 break; 1067 case PF_INET: 1068 case PF_INET6: 1069 switch (type) { 1070 case SOCK_STREAM: 1071 if (default_protocol_stream(protocol)) 1072 return SECCLASS_TCP_SOCKET; 1073 else 1074 return SECCLASS_RAWIP_SOCKET; 1075 case SOCK_DGRAM: 1076 if (default_protocol_dgram(protocol)) 1077 return SECCLASS_UDP_SOCKET; 1078 else 1079 return SECCLASS_RAWIP_SOCKET; 1080 case SOCK_DCCP: 1081 return SECCLASS_DCCP_SOCKET; 1082 default: 1083 return SECCLASS_RAWIP_SOCKET; 1084 } 1085 break; 1086 case PF_NETLINK: 1087 switch (protocol) { 1088 case NETLINK_ROUTE: 1089 return SECCLASS_NETLINK_ROUTE_SOCKET; 1090 case NETLINK_FIREWALL: 1091 return SECCLASS_NETLINK_FIREWALL_SOCKET; 1092 case NETLINK_INET_DIAG: 1093 return SECCLASS_NETLINK_TCPDIAG_SOCKET; 1094 case NETLINK_NFLOG: 1095 return SECCLASS_NETLINK_NFLOG_SOCKET; 1096 case NETLINK_XFRM: 1097 return SECCLASS_NETLINK_XFRM_SOCKET; 1098 case NETLINK_SELINUX: 1099 return SECCLASS_NETLINK_SELINUX_SOCKET; 1100 case NETLINK_AUDIT: 1101 return SECCLASS_NETLINK_AUDIT_SOCKET; 1102 case NETLINK_IP6_FW: 1103 return SECCLASS_NETLINK_IP6FW_SOCKET; 1104 case NETLINK_DNRTMSG: 1105 return SECCLASS_NETLINK_DNRT_SOCKET; 1106 case NETLINK_KOBJECT_UEVENT: 1107 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; 1108 default: 1109 return SECCLASS_NETLINK_SOCKET; 1110 } 1111 case PF_PACKET: 1112 return SECCLASS_PACKET_SOCKET; 1113 case PF_KEY: 1114 return SECCLASS_KEY_SOCKET; 1115 case PF_APPLETALK: 1116 return SECCLASS_APPLETALK_SOCKET; 1117 } 1118 1119 return SECCLASS_SOCKET; 1120} 1121 1122#ifdef CONFIG_PROC_FS 1123static int selinux_proc_get_sid(struct proc_dir_entry *de, 1124 u16 tclass, 1125 u32 *sid) 1126{ 1127 int buflen, rc; 1128 char *buffer, *path, *end; 1129 1130 buffer = (char *)__get_free_page(GFP_KERNEL); 1131 if (!buffer) 1132 return -ENOMEM; 1133 1134 buflen = PAGE_SIZE; 1135 end = buffer+buflen; 1136 *--end = '\0'; 1137 buflen--; 1138 path = end-1; 1139 *path = '/'; 1140 while (de && de != de->parent) { 1141 buflen -= de->namelen + 1; 1142 if (buflen < 0) 1143 break; 1144 end -= de->namelen; 1145 memcpy(end, de->name, de->namelen); 1146 *--end = '/'; 1147 path = end; 1148 de = de->parent; 1149 } 1150 rc = security_genfs_sid("proc", path, tclass, sid); 1151 free_page((unsigned long)buffer); 1152 return rc; 1153} 1154#else 1155static int selinux_proc_get_sid(struct proc_dir_entry *de, 1156 u16 tclass, 1157 u32 *sid) 1158{ 1159 return -EINVAL; 1160} 1161#endif 1162 1163/* The inode's security attributes must be initialized before first use. */ 1164static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) 1165{ 1166 struct superblock_security_struct *sbsec = NULL; 1167 struct inode_security_struct *isec = inode->i_security; 1168 u32 sid; 1169 struct dentry *dentry; 1170#define INITCONTEXTLEN 255 1171 char *context = NULL; 1172 unsigned len = 0; 1173 int rc = 0; 1174 1175 if (isec->initialized) 1176 goto out; 1177 1178 mutex_lock(&isec->lock); 1179 if (isec->initialized) 1180 goto out_unlock; 1181 1182 sbsec = inode->i_sb->s_security; 1183 if (!(sbsec->flags & SE_SBINITIALIZED)) { 1184 /* Defer initialization until selinux_complete_init, 1185 after the initial policy is loaded and the security 1186 server is ready to handle calls. */ 1187 spin_lock(&sbsec->isec_lock); 1188 if (list_empty(&isec->list)) 1189 list_add(&isec->list, &sbsec->isec_head); 1190 spin_unlock(&sbsec->isec_lock); 1191 goto out_unlock; 1192 } 1193 1194 switch (sbsec->behavior) { 1195 case SECURITY_FS_USE_XATTR: 1196 if (!inode->i_op->getxattr) { 1197 isec->sid = sbsec->def_sid; 1198 break; 1199 } 1200 1201 /* Need a dentry, since the xattr API requires one. 1202 Life would be simpler if we could just pass the inode. */ 1203 if (opt_dentry) { 1204 /* Called from d_instantiate or d_splice_alias. */ 1205 dentry = dget(opt_dentry); 1206 } else { 1207 /* Called from selinux_complete_init, try to find a dentry. */ 1208 dentry = d_find_alias(inode); 1209 } 1210 if (!dentry) { 1211 /* 1212 * this is can be hit on boot when a file is accessed 1213 * before the policy is loaded. When we load policy we 1214 * may find inodes that have no dentry on the 1215 * sbsec->isec_head list. No reason to complain as these 1216 * will get fixed up the next time we go through 1217 * inode_doinit with a dentry, before these inodes could 1218 * be used again by userspace. 1219 */ 1220 goto out_unlock; 1221 } 1222 1223 len = INITCONTEXTLEN; 1224 context = kmalloc(len+1, GFP_NOFS); 1225 if (!context) { 1226 rc = -ENOMEM; 1227 dput(dentry); 1228 goto out_unlock; 1229 } 1230 context[len] = '\0'; 1231 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, 1232 context, len); 1233 if (rc == -ERANGE) { 1234 kfree(context); 1235 1236 /* Need a larger buffer. Query for the right size. */ 1237 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, 1238 NULL, 0); 1239 if (rc < 0) { 1240 dput(dentry); 1241 goto out_unlock; 1242 } 1243 len = rc; 1244 context = kmalloc(len+1, GFP_NOFS); 1245 if (!context) { 1246 rc = -ENOMEM; 1247 dput(dentry); 1248 goto out_unlock; 1249 } 1250 context[len] = '\0'; 1251 rc = inode->i_op->getxattr(dentry, 1252 XATTR_NAME_SELINUX, 1253 context, len); 1254 } 1255 dput(dentry); 1256 if (rc < 0) { 1257 if (rc != -ENODATA) { 1258 printk(KERN_WARNING "SELinux: %s: getxattr returned " 1259 "%d for dev=%s ino=%ld\n", __func__, 1260 -rc, inode->i_sb->s_id, inode->i_ino); 1261 kfree(context); 1262 goto out_unlock; 1263 } 1264 /* Map ENODATA to the default file SID */ 1265 sid = sbsec->def_sid; 1266 rc = 0; 1267 } else { 1268 rc = security_context_to_sid_default(context, rc, &sid, 1269 sbsec->def_sid, 1270 GFP_NOFS); 1271 if (rc) { 1272 char *dev = inode->i_sb->s_id; 1273 unsigned long ino = inode->i_ino; 1274 1275 if (rc == -EINVAL) { 1276 if (printk_ratelimit()) 1277 printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid " 1278 "context=%s. This indicates you may need to relabel the inode or the " 1279 "filesystem in question.\n", ino, dev, context); 1280 } else { 1281 printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) " 1282 "returned %d for dev=%s ino=%ld\n", 1283 __func__, context, -rc, dev, ino); 1284 } 1285 kfree(context); 1286 /* Leave with the unlabeled SID */ 1287 rc = 0; 1288 break; 1289 } 1290 } 1291 kfree(context); 1292 isec->sid = sid; 1293 break; 1294 case SECURITY_FS_USE_TASK: 1295 isec->sid = isec->task_sid; 1296 break; 1297 case SECURITY_FS_USE_TRANS: 1298 /* Default to the fs SID. */ 1299 isec->sid = sbsec->sid; 1300 1301 /* Try to obtain a transition SID. */ 1302 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1303 rc = security_transition_sid(isec->task_sid, 1304 sbsec->sid, 1305 isec->sclass, 1306 &sid); 1307 if (rc) 1308 goto out_unlock; 1309 isec->sid = sid; 1310 break; 1311 case SECURITY_FS_USE_MNTPOINT: 1312 isec->sid = sbsec->mntpoint_sid; 1313 break; 1314 default: 1315 /* Default to the fs superblock SID. */ 1316 isec->sid = sbsec->sid; 1317 1318 if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) { 1319 struct proc_inode *proci = PROC_I(inode); 1320 if (proci->pde) { 1321 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1322 rc = selinux_proc_get_sid(proci->pde, 1323 isec->sclass, 1324 &sid); 1325 if (rc) 1326 goto out_unlock; 1327 isec->sid = sid; 1328 } 1329 } 1330 break; 1331 } 1332 1333 isec->initialized = 1; 1334 1335out_unlock: 1336 mutex_unlock(&isec->lock); 1337out: 1338 if (isec->sclass == SECCLASS_FILE) 1339 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1340 return rc; 1341} 1342 1343/* Convert a Linux signal to an access vector. */ 1344static inline u32 signal_to_av(int sig) 1345{ 1346 u32 perm = 0; 1347 1348 switch (sig) { 1349 case SIGCHLD: 1350 /* Commonly granted from child to parent. */ 1351 perm = PROCESS__SIGCHLD; 1352 break; 1353 case SIGKILL: 1354 /* Cannot be caught or ignored */ 1355 perm = PROCESS__SIGKILL; 1356 break; 1357 case SIGSTOP: 1358 /* Cannot be caught or ignored */ 1359 perm = PROCESS__SIGSTOP; 1360 break; 1361 default: 1362 /* All other signals. */ 1363 perm = PROCESS__SIGNAL; 1364 break; 1365 } 1366 1367 return perm; 1368} 1369 1370/* 1371 * Check permission between a pair of credentials 1372 * fork check, ptrace check, etc. 1373 */ 1374static int cred_has_perm(const struct cred *actor, 1375 const struct cred *target, 1376 u32 perms) 1377{ 1378 u32 asid = cred_sid(actor), tsid = cred_sid(target); 1379 1380 return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL); 1381} 1382 1383/* 1384 * Check permission between a pair of tasks, e.g. signal checks, 1385 * fork check, ptrace check, etc. 1386 * tsk1 is the actor and tsk2 is the target 1387 * - this uses the default subjective creds of tsk1 1388 */ 1389static int task_has_perm(const struct task_struct *tsk1, 1390 const struct task_struct *tsk2, 1391 u32 perms) 1392{ 1393 const struct task_security_struct *__tsec1, *__tsec2; 1394 u32 sid1, sid2; 1395 1396 rcu_read_lock(); 1397 __tsec1 = __task_cred(tsk1)->security; sid1 = __tsec1->sid; 1398 __tsec2 = __task_cred(tsk2)->security; sid2 = __tsec2->sid; 1399 rcu_read_unlock(); 1400 return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL); 1401} 1402 1403/* 1404 * Check permission between current and another task, e.g. signal checks, 1405 * fork check, ptrace check, etc. 1406 * current is the actor and tsk2 is the target 1407 * - this uses current's subjective creds 1408 */ 1409static int current_has_perm(const struct task_struct *tsk, 1410 u32 perms) 1411{ 1412 u32 sid, tsid; 1413 1414 sid = current_sid(); 1415 tsid = task_sid(tsk); 1416 return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL); 1417} 1418 1419#if CAP_LAST_CAP > 63 1420#error Fix SELinux to handle capabilities > 63. 1421#endif 1422 1423/* Check whether a task is allowed to use a capability. */ 1424static int task_has_capability(struct task_struct *tsk, 1425 const struct cred *cred, 1426 int cap, int audit) 1427{ 1428 struct common_audit_data ad; 1429 struct av_decision avd; 1430 u16 sclass; 1431 u32 sid = cred_sid(cred); 1432 u32 av = CAP_TO_MASK(cap); 1433 int rc; 1434 1435 COMMON_AUDIT_DATA_INIT(&ad, CAP); 1436 ad.tsk = tsk; 1437 ad.u.cap = cap; 1438 1439 switch (CAP_TO_INDEX(cap)) { 1440 case 0: 1441 sclass = SECCLASS_CAPABILITY; 1442 break; 1443 case 1: 1444 sclass = SECCLASS_CAPABILITY2; 1445 break; 1446 default: 1447 printk(KERN_ERR 1448 "SELinux: out of range capability %d\n", cap); 1449 BUG(); 1450 } 1451 1452 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd); 1453 if (audit == SECURITY_CAP_AUDIT) 1454 avc_audit(sid, sid, sclass, av, &avd, rc, &ad); 1455 return rc; 1456} 1457 1458/* Check whether a task is allowed to use a system operation. */ 1459static int task_has_system(struct task_struct *tsk, 1460 u32 perms) 1461{ 1462 u32 sid = task_sid(tsk); 1463 1464 return avc_has_perm(sid, SECINITSID_KERNEL, 1465 SECCLASS_SYSTEM, perms, NULL); 1466} 1467 1468/* Check whether a task has a particular permission to an inode. 1469 The 'adp' parameter is optional and allows other audit 1470 data to be passed (e.g. the dentry). */ 1471static int inode_has_perm(const struct cred *cred, 1472 struct inode *inode, 1473 u32 perms, 1474 struct common_audit_data *adp) 1475{ 1476 struct inode_security_struct *isec; 1477 struct common_audit_data ad; 1478 u32 sid; 1479 1480 validate_creds(cred); 1481 1482 if (unlikely(IS_PRIVATE(inode))) 1483 return 0; 1484 1485 sid = cred_sid(cred); 1486 isec = inode->i_security; 1487 1488 if (!adp) { 1489 adp = &ad; 1490 COMMON_AUDIT_DATA_INIT(&ad, FS); 1491 ad.u.fs.inode = inode; 1492 } 1493 1494 return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp); 1495} 1496 1497/* Same as inode_has_perm, but pass explicit audit data containing 1498 the dentry to help the auditing code to more easily generate the 1499 pathname if needed. */ 1500static inline int dentry_has_perm(const struct cred *cred, 1501 struct vfsmount *mnt, 1502 struct dentry *dentry, 1503 u32 av) 1504{ 1505 struct inode *inode = dentry->d_inode; 1506 struct common_audit_data ad; 1507 1508 COMMON_AUDIT_DATA_INIT(&ad, FS); 1509 ad.u.fs.path.mnt = mnt; 1510 ad.u.fs.path.dentry = dentry; 1511 return inode_has_perm(cred, inode, av, &ad); 1512} 1513 1514/* Check whether a task can use an open file descriptor to 1515 access an inode in a given way. Check access to the 1516 descriptor itself, and then use dentry_has_perm to 1517 check a particular permission to the file. 1518 Access to the descriptor is implicitly granted if it 1519 has the same SID as the process. If av is zero, then 1520 access to the file is not checked, e.g. for cases 1521 where only the descriptor is affected like seek. */ 1522static int file_has_perm(const struct cred *cred, 1523 struct file *file, 1524 u32 av) 1525{ 1526 struct file_security_struct *fsec = file->f_security; 1527 struct inode *inode = file->f_path.dentry->d_inode; 1528 struct common_audit_data ad; 1529 u32 sid = cred_sid(cred); 1530 int rc; 1531 1532 COMMON_AUDIT_DATA_INIT(&ad, FS); 1533 ad.u.fs.path = file->f_path; 1534 1535 if (sid != fsec->sid) { 1536 rc = avc_has_perm(sid, fsec->sid, 1537 SECCLASS_FD, 1538 FD__USE, 1539 &ad); 1540 if (rc) 1541 goto out; 1542 } 1543 1544 /* av is zero if only checking access to the descriptor. */ 1545 rc = 0; 1546 if (av) 1547 rc = inode_has_perm(cred, inode, av, &ad); 1548 1549out: 1550 return rc; 1551} 1552 1553/* Check whether a task can create a file. */ 1554static int may_create(struct inode *dir, 1555 struct dentry *dentry, 1556 u16 tclass) 1557{ 1558 const struct task_security_struct *tsec = current_security(); 1559 struct inode_security_struct *dsec; 1560 struct superblock_security_struct *sbsec; 1561 u32 sid, newsid; 1562 struct common_audit_data ad; 1563 int rc; 1564 1565 dsec = dir->i_security; 1566 sbsec = dir->i_sb->s_security; 1567 1568 sid = tsec->sid; 1569 newsid = tsec->create_sid; 1570 1571 COMMON_AUDIT_DATA_INIT(&ad, FS); 1572 ad.u.fs.path.dentry = dentry; 1573 1574 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, 1575 DIR__ADD_NAME | DIR__SEARCH, 1576 &ad); 1577 if (rc) 1578 return rc; 1579 1580 if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) { 1581 rc = security_transition_sid(sid, dsec->sid, tclass, &newsid); 1582 if (rc) 1583 return rc; 1584 } 1585 1586 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad); 1587 if (rc) 1588 return rc; 1589 1590 return avc_has_perm(newsid, sbsec->sid, 1591 SECCLASS_FILESYSTEM, 1592 FILESYSTEM__ASSOCIATE, &ad); 1593} 1594 1595/* Check whether a task can create a key. */ 1596static int may_create_key(u32 ksid, 1597 struct task_struct *ctx) 1598{ 1599 u32 sid = task_sid(ctx); 1600 1601 return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL); 1602} 1603 1604#define MAY_LINK 0 1605#define MAY_UNLINK 1 1606#define MAY_RMDIR 2 1607 1608/* Check whether a task can link, unlink, or rmdir a file/directory. */ 1609static int may_link(struct inode *dir, 1610 struct dentry *dentry, 1611 int kind) 1612 1613{ 1614 struct inode_security_struct *dsec, *isec; 1615 struct common_audit_data ad; 1616 u32 sid = current_sid(); 1617 u32 av; 1618 int rc; 1619 1620 dsec = dir->i_security; 1621 isec = dentry->d_inode->i_security; 1622 1623 COMMON_AUDIT_DATA_INIT(&ad, FS); 1624 ad.u.fs.path.dentry = dentry; 1625 1626 av = DIR__SEARCH; 1627 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); 1628 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad); 1629 if (rc) 1630 return rc; 1631 1632 switch (kind) { 1633 case MAY_LINK: 1634 av = FILE__LINK; 1635 break; 1636 case MAY_UNLINK: 1637 av = FILE__UNLINK; 1638 break; 1639 case MAY_RMDIR: 1640 av = DIR__RMDIR; 1641 break; 1642 default: 1643 printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n", 1644 __func__, kind); 1645 return 0; 1646 } 1647 1648 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad); 1649 return rc; 1650} 1651 1652static inline int may_rename(struct inode *old_dir, 1653 struct dentry *old_dentry, 1654 struct inode *new_dir, 1655 struct dentry *new_dentry) 1656{ 1657 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; 1658 struct common_audit_data ad; 1659 u32 sid = current_sid(); 1660 u32 av; 1661 int old_is_dir, new_is_dir; 1662 int rc; 1663 1664 old_dsec = old_dir->i_security; 1665 old_isec = old_dentry->d_inode->i_security; 1666 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode); 1667 new_dsec = new_dir->i_security; 1668 1669 COMMON_AUDIT_DATA_INIT(&ad, FS); 1670 1671 ad.u.fs.path.dentry = old_dentry; 1672 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR, 1673 DIR__REMOVE_NAME | DIR__SEARCH, &ad); 1674 if (rc) 1675 return rc; 1676 rc = avc_has_perm(sid, old_isec->sid, 1677 old_isec->sclass, FILE__RENAME, &ad); 1678 if (rc) 1679 return rc; 1680 if (old_is_dir && new_dir != old_dir) { 1681 rc = avc_has_perm(sid, old_isec->sid, 1682 old_isec->sclass, DIR__REPARENT, &ad); 1683 if (rc) 1684 return rc; 1685 } 1686 1687 ad.u.fs.path.dentry = new_dentry; 1688 av = DIR__ADD_NAME | DIR__SEARCH; 1689 if (new_dentry->d_inode) 1690 av |= DIR__REMOVE_NAME; 1691 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad); 1692 if (rc) 1693 return rc; 1694 if (new_dentry->d_inode) { 1695 new_isec = new_dentry->d_inode->i_security; 1696 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode); 1697 rc = avc_has_perm(sid, new_isec->sid, 1698 new_isec->sclass, 1699 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); 1700 if (rc) 1701 return rc; 1702 } 1703 1704 return 0; 1705} 1706 1707/* Check whether a task can perform a filesystem operation. */ 1708static int superblock_has_perm(const struct cred *cred, 1709 struct super_block *sb, 1710 u32 perms, 1711 struct common_audit_data *ad) 1712{ 1713 struct superblock_security_struct *sbsec; 1714 u32 sid = cred_sid(cred); 1715 1716 sbsec = sb->s_security; 1717 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); 1718} 1719 1720/* Convert a Linux mode and permission mask to an access vector. */ 1721static inline u32 file_mask_to_av(int mode, int mask) 1722{ 1723 u32 av = 0; 1724 1725 if ((mode & S_IFMT) != S_IFDIR) { 1726 if (mask & MAY_EXEC) 1727 av |= FILE__EXECUTE; 1728 if (mask & MAY_READ) 1729 av |= FILE__READ; 1730 1731 if (mask & MAY_APPEND) 1732 av |= FILE__APPEND; 1733 else if (mask & MAY_WRITE) 1734 av |= FILE__WRITE; 1735 1736 } else { 1737 if (mask & MAY_EXEC) 1738 av |= DIR__SEARCH; 1739 if (mask & MAY_WRITE) 1740 av |= DIR__WRITE; 1741 if (mask & MAY_READ) 1742 av |= DIR__READ; 1743 } 1744 1745 return av; 1746} 1747 1748/* Convert a Linux file to an access vector. */ 1749static inline u32 file_to_av(struct file *file) 1750{ 1751 u32 av = 0; 1752 1753 if (file->f_mode & FMODE_READ) 1754 av |= FILE__READ; 1755 if (file->f_mode & FMODE_WRITE) { 1756 if (file->f_flags & O_APPEND) 1757 av |= FILE__APPEND; 1758 else 1759 av |= FILE__WRITE; 1760 } 1761 if (!av) { 1762 /* 1763 * Special file opened with flags 3 for ioctl-only use. 1764 */ 1765 av = FILE__IOCTL; 1766 } 1767 1768 return av; 1769} 1770 1771/* 1772 * Convert a file to an access vector and include the correct open 1773 * open permission. 1774 */ 1775static inline u32 open_file_to_av(struct file *file) 1776{ 1777 u32 av = file_to_av(file); 1778 1779 if (selinux_policycap_openperm) 1780 av |= FILE__OPEN; 1781 1782 return av; 1783} 1784 1785/* Hook functions begin here. */ 1786 1787static int selinux_ptrace_access_check(struct task_struct *child, 1788 unsigned int mode) 1789{ 1790 int rc; 1791 1792 rc = cap_ptrace_access_check(child, mode); 1793 if (rc) 1794 return rc; 1795 1796 if (mode == PTRACE_MODE_READ) { 1797 u32 sid = current_sid(); 1798 u32 csid = task_sid(child); 1799 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL); 1800 } 1801 1802 return current_has_perm(child, PROCESS__PTRACE); 1803} 1804 1805static int selinux_ptrace_traceme(struct task_struct *parent) 1806{ 1807 int rc; 1808 1809 rc = cap_ptrace_traceme(parent); 1810 if (rc) 1811 return rc; 1812 1813 return task_has_perm(parent, current, PROCESS__PTRACE); 1814} 1815 1816static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, 1817 kernel_cap_t *inheritable, kernel_cap_t *permitted) 1818{ 1819 int error; 1820 1821 error = current_has_perm(target, PROCESS__GETCAP); 1822 if (error) 1823 return error; 1824 1825 return cap_capget(target, effective, inheritable, permitted); 1826} 1827 1828static int selinux_capset(struct cred *new, const struct cred *old, 1829 const kernel_cap_t *effective, 1830 const kernel_cap_t *inheritable, 1831 const kernel_cap_t *permitted) 1832{ 1833 int error; 1834 1835 error = cap_capset(new, old, 1836 effective, inheritable, permitted); 1837 if (error) 1838 return error; 1839 1840 return cred_has_perm(old, new, PROCESS__SETCAP); 1841} 1842 1843/* 1844 * (This comment used to live with the selinux_task_setuid hook, 1845 * which was removed). 1846 * 1847 * Since setuid only affects the current process, and since the SELinux 1848 * controls are not based on the Linux identity attributes, SELinux does not 1849 * need to control this operation. However, SELinux does control the use of 1850 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook. 1851 */ 1852 1853static int selinux_capable(struct task_struct *tsk, const struct cred *cred, 1854 int cap, int audit) 1855{ 1856 int rc; 1857 1858 rc = cap_capable(tsk, cred, cap, audit); 1859 if (rc) 1860 return rc; 1861 1862 return task_has_capability(tsk, cred, cap, audit); 1863} 1864 1865static int selinux_sysctl_get_sid(ctl_table *table, u16 tclass, u32 *sid) 1866{ 1867 int buflen, rc; 1868 char *buffer, *path, *end; 1869 1870 rc = -ENOMEM; 1871 buffer = (char *)__get_free_page(GFP_KERNEL); 1872 if (!buffer) 1873 goto out; 1874 1875 buflen = PAGE_SIZE; 1876 end = buffer+buflen; 1877 *--end = '\0'; 1878 buflen--; 1879 path = end-1; 1880 *path = '/'; 1881 while (table) { 1882 const char *name = table->procname; 1883 size_t namelen = strlen(name); 1884 buflen -= namelen + 1; 1885 if (buflen < 0) 1886 goto out_free; 1887 end -= namelen; 1888 memcpy(end, name, namelen); 1889 *--end = '/'; 1890 path = end; 1891 table = table->parent; 1892 } 1893 buflen -= 4; 1894 if (buflen < 0) 1895 goto out_free; 1896 end -= 4; 1897 memcpy(end, "/sys", 4); 1898 path = end; 1899 rc = security_genfs_sid("proc", path, tclass, sid); 1900out_free: 1901 free_page((unsigned long)buffer); 1902out: 1903 return rc; 1904} 1905 1906static int selinux_sysctl(ctl_table *table, int op) 1907{ 1908 int error = 0; 1909 u32 av; 1910 u32 tsid, sid; 1911 int rc; 1912 1913 sid = current_sid(); 1914 1915 rc = selinux_sysctl_get_sid(table, (op == 0001) ? 1916 SECCLASS_DIR : SECCLASS_FILE, &tsid); 1917 if (rc) { 1918 /* Default to the well-defined sysctl SID. */ 1919 tsid = SECINITSID_SYSCTL; 1920 } 1921 1922 /* The op values are "defined" in sysctl.c, thereby creating 1923 * a bad coupling between this module and sysctl.c */ 1924 if (op == 001) { 1925 error = avc_has_perm(sid, tsid, 1926 SECCLASS_DIR, DIR__SEARCH, NULL); 1927 } else { 1928 av = 0; 1929 if (op & 004) 1930 av |= FILE__READ; 1931 if (op & 002) 1932 av |= FILE__WRITE; 1933 if (av) 1934 error = avc_has_perm(sid, tsid, 1935 SECCLASS_FILE, av, NULL); 1936 } 1937 1938 return error; 1939} 1940 1941static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb) 1942{ 1943 const struct cred *cred = current_cred(); 1944 int rc = 0; 1945 1946 if (!sb) 1947 return 0; 1948 1949 switch (cmds) { 1950 case Q_SYNC: 1951 case Q_QUOTAON: 1952 case Q_QUOTAOFF: 1953 case Q_SETINFO: 1954 case Q_SETQUOTA: 1955 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL); 1956 break; 1957 case Q_GETFMT: 1958 case Q_GETINFO: 1959 case Q_GETQUOTA: 1960 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL); 1961 break; 1962 default: 1963 rc = 0; /* let the kernel handle invalid cmds */ 1964 break; 1965 } 1966 return rc; 1967} 1968 1969static int selinux_quota_on(struct dentry *dentry) 1970{ 1971 const struct cred *cred = current_cred(); 1972 1973 return dentry_has_perm(cred, NULL, dentry, FILE__QUOTAON); 1974} 1975 1976static int selinux_syslog(int type, bool from_file) 1977{ 1978 int rc; 1979 1980 rc = cap_syslog(type, from_file); 1981 if (rc) 1982 return rc; 1983 1984 switch (type) { 1985 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */ 1986 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */ 1987 rc = task_has_system(current, SYSTEM__SYSLOG_READ); 1988 break; 1989 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */ 1990 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */ 1991 /* Set level of messages printed to console */ 1992 case SYSLOG_ACTION_CONSOLE_LEVEL: 1993 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE); 1994 break; 1995 case SYSLOG_ACTION_CLOSE: /* Close log */ 1996 case SYSLOG_ACTION_OPEN: /* Open log */ 1997 case SYSLOG_ACTION_READ: /* Read from log */ 1998 case SYSLOG_ACTION_READ_CLEAR: /* Read/clear last kernel messages */ 1999 case SYSLOG_ACTION_CLEAR: /* Clear ring buffer */ 2000 default: 2001 rc = task_has_system(current, SYSTEM__SYSLOG_MOD); 2002 break; 2003 } 2004 return rc; 2005} 2006 2007/* 2008 * Check that a process has enough memory to allocate a new virtual 2009 * mapping. 0 means there is enough memory for the allocation to 2010 * succeed and -ENOMEM implies there is not. 2011 * 2012 * Do not audit the selinux permission check, as this is applied to all 2013 * processes that allocate mappings. 2014 */ 2015static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) 2016{ 2017 int rc, cap_sys_admin = 0; 2018 2019 rc = selinux_capable(current, current_cred(), CAP_SYS_ADMIN, 2020 SECURITY_CAP_NOAUDIT); 2021 if (rc == 0) 2022 cap_sys_admin = 1; 2023 2024 return __vm_enough_memory(mm, pages, cap_sys_admin); 2025} 2026 2027/* binprm security operations */ 2028 2029static int selinux_bprm_set_creds(struct linux_binprm *bprm) 2030{ 2031 const struct task_security_struct *old_tsec; 2032 struct task_security_struct *new_tsec; 2033 struct inode_security_struct *isec; 2034 struct common_audit_data ad; 2035 struct inode *inode = bprm->file->f_path.dentry->d_inode; 2036 int rc; 2037 2038 rc = cap_bprm_set_creds(bprm); 2039 if (rc) 2040 return rc; 2041 2042 /* SELinux context only depends on initial program or script and not 2043 * the script interpreter */ 2044 if (bprm->cred_prepared) 2045 return 0; 2046 2047 old_tsec = current_security(); 2048 new_tsec = bprm->cred->security; 2049 isec = inode->i_security; 2050 2051 /* Default to the current task SID. */ 2052 new_tsec->sid = old_tsec->sid; 2053 new_tsec->osid = old_tsec->sid; 2054 2055 /* Reset fs, key, and sock SIDs on execve. */ 2056 new_tsec->create_sid = 0; 2057 new_tsec->keycreate_sid = 0; 2058 new_tsec->sockcreate_sid = 0; 2059 2060 if (old_tsec->exec_sid) { 2061 new_tsec->sid = old_tsec->exec_sid; 2062 /* Reset exec SID on execve. */ 2063 new_tsec->exec_sid = 0; 2064 } else { 2065 /* Check for a default transition on this program. */ 2066 rc = security_transition_sid(old_tsec->sid, isec->sid, 2067 SECCLASS_PROCESS, &new_tsec->sid); 2068 if (rc) 2069 return rc; 2070 } 2071 2072 COMMON_AUDIT_DATA_INIT(&ad, FS); 2073 ad.u.fs.path = bprm->file->f_path; 2074 2075 if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) 2076 new_tsec->sid = old_tsec->sid; 2077 2078 if (new_tsec->sid == old_tsec->sid) { 2079 rc = avc_has_perm(old_tsec->sid, isec->sid, 2080 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); 2081 if (rc) 2082 return rc; 2083 } else { 2084 /* Check permissions for the transition. */ 2085 rc = avc_has_perm(old_tsec->sid, new_tsec->sid, 2086 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); 2087 if (rc) 2088 return rc; 2089 2090 rc = avc_has_perm(new_tsec->sid, isec->sid, 2091 SECCLASS_FILE, FILE__ENTRYPOINT, &ad); 2092 if (rc) 2093 return rc; 2094 2095 /* Check for shared state */ 2096 if (bprm->unsafe & LSM_UNSAFE_SHARE) { 2097 rc = avc_has_perm(old_tsec->sid, new_tsec->sid, 2098 SECCLASS_PROCESS, PROCESS__SHARE, 2099 NULL); 2100 if (rc) 2101 return -EPERM; 2102 } 2103 2104 /* Make sure that anyone attempting to ptrace over a task that 2105 * changes its SID has the appropriate permit */ 2106 if (bprm->unsafe & 2107 (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { 2108 struct task_struct *tracer; 2109 struct task_security_struct *sec; 2110 u32 ptsid = 0; 2111 2112 rcu_read_lock(); 2113 tracer = tracehook_tracer_task(current); 2114 if (likely(tracer != NULL)) { 2115 sec = __task_cred(tracer)->security; 2116 ptsid = sec->sid; 2117 } 2118 rcu_read_unlock(); 2119 2120 if (ptsid != 0) { 2121 rc = avc_has_perm(ptsid, new_tsec->sid, 2122 SECCLASS_PROCESS, 2123 PROCESS__PTRACE, NULL); 2124 if (rc) 2125 return -EPERM; 2126 } 2127 } 2128 2129 /* Clear any possibly unsafe personality bits on exec: */ 2130 bprm->per_clear |= PER_CLEAR_ON_SETID; 2131 } 2132 2133 return 0; 2134} 2135 2136static int selinux_bprm_secureexec(struct linux_binprm *bprm) 2137{ 2138 const struct task_security_struct *tsec = current_security(); 2139 u32 sid, osid; 2140 int atsecure = 0; 2141 2142 sid = tsec->sid; 2143 osid = tsec->osid; 2144 2145 if (osid != sid) { 2146 /* Enable secure mode for SIDs transitions unless 2147 the noatsecure permission is granted between 2148 the two SIDs, i.e. ahp returns 0. */ 2149 atsecure = avc_has_perm(osid, sid, 2150 SECCLASS_PROCESS, 2151 PROCESS__NOATSECURE, NULL); 2152 } 2153 2154 return (atsecure || cap_bprm_secureexec(bprm)); 2155} 2156 2157extern struct vfsmount *selinuxfs_mount; 2158extern struct dentry *selinux_null; 2159 2160/* Derived from fs/exec.c:flush_old_files. */ 2161static inline void flush_unauthorized_files(const struct cred *cred, 2162 struct files_struct *files) 2163{ 2164 struct common_audit_data ad; 2165 struct file *file, *devnull = NULL; 2166 struct tty_struct *tty; 2167 struct fdtable *fdt; 2168 long j = -1; 2169 int drop_tty = 0; 2170 2171 tty = get_current_tty(); 2172 if (tty) { 2173 spin_lock(&tty_files_lock); 2174 if (!list_empty(&tty->tty_files)) { 2175 struct tty_file_private *file_priv; 2176 struct inode *inode; 2177 2178 /* Revalidate access to controlling tty. 2179 Use inode_has_perm on the tty inode directly rather 2180 than using file_has_perm, as this particular open 2181 file may belong to another process and we are only 2182 interested in the inode-based check here. */ 2183 file_priv = list_first_entry(&tty->tty_files, 2184 struct tty_file_private, list); 2185 file = file_priv->file; 2186 inode = file->f_path.dentry->d_inode; 2187 if (inode_has_perm(cred, inode, 2188 FILE__READ | FILE__WRITE, NULL)) { 2189 drop_tty = 1; 2190 } 2191 } 2192 spin_unlock(&tty_files_lock); 2193 tty_kref_put(tty); 2194 } 2195 /* Reset controlling tty. */ 2196 if (drop_tty) 2197 no_tty(); 2198 2199 /* Revalidate access to inherited open files. */ 2200 2201 COMMON_AUDIT_DATA_INIT(&ad, FS); 2202 2203 spin_lock(&files->file_lock); 2204 for (;;) { 2205 unsigned long set, i; 2206 int fd; 2207 2208 j++; 2209 i = j * __NFDBITS; 2210 fdt = files_fdtable(files); 2211 if (i >= fdt->max_fds) 2212 break; 2213 set = fdt->open_fds->fds_bits[j]; 2214 if (!set) 2215 continue; 2216 spin_unlock(&files->file_lock); 2217 for ( ; set ; i++, set >>= 1) { 2218 if (set & 1) { 2219 file = fget(i); 2220 if (!file) 2221 continue; 2222 if (file_has_perm(cred, 2223 file, 2224 file_to_av(file))) { 2225 sys_close(i); 2226 fd = get_unused_fd(); 2227 if (fd != i) { 2228 if (fd >= 0) 2229 put_unused_fd(fd); 2230 fput(file); 2231 continue; 2232 } 2233 if (devnull) { 2234 get_file(devnull); 2235 } else { 2236 devnull = dentry_open( 2237 dget(selinux_null), 2238 mntget(selinuxfs_mount), 2239 O_RDWR, cred); 2240 if (IS_ERR(devnull)) { 2241 devnull = NULL; 2242 put_unused_fd(fd); 2243 fput(file); 2244 continue; 2245 } 2246 } 2247 fd_install(fd, devnull); 2248 } 2249 fput(file); 2250 } 2251 } 2252 spin_lock(&files->file_lock); 2253 2254 } 2255 spin_unlock(&files->file_lock); 2256} 2257 2258/* 2259 * Prepare a process for imminent new credential changes due to exec 2260 */ 2261static void selinux_bprm_committing_creds(struct linux_binprm *bprm) 2262{ 2263 struct task_security_struct *new_tsec; 2264 struct rlimit *rlim, *initrlim; 2265 int rc, i; 2266 2267 new_tsec = bprm->cred->security; 2268 if (new_tsec->sid == new_tsec->osid) 2269 return; 2270 2271 /* Close files for which the new task SID is not authorized. */ 2272 flush_unauthorized_files(bprm->cred, current->files); 2273 2274 /* Always clear parent death signal on SID transitions. */ 2275 current->pdeath_signal = 0; 2276 2277 /* Check whether the new SID can inherit resource limits from the old 2278 * SID. If not, reset all soft limits to the lower of the current 2279 * task's hard limit and the init task's soft limit. 2280 * 2281 * Note that the setting of hard limits (even to lower them) can be 2282 * controlled by the setrlimit check. The inclusion of the init task's 2283 * soft limit into the computation is to avoid resetting soft limits 2284 * higher than the default soft limit for cases where the default is 2285 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. 2286 */ 2287 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, 2288 PROCESS__RLIMITINH, NULL); 2289 if (rc) { 2290 /* protect against do_prlimit() */ 2291 task_lock(current); 2292 for (i = 0; i < RLIM_NLIMITS; i++) { 2293 rlim = current->signal->rlim + i; 2294 initrlim = init_task.signal->rlim + i; 2295 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); 2296 } 2297 task_unlock(current); 2298 update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); 2299 } 2300} 2301 2302/* 2303 * Clean up the process immediately after the installation of new credentials 2304 * due to exec 2305 */ 2306static void selinux_bprm_committed_creds(struct linux_binprm *bprm) 2307{ 2308 const struct task_security_struct *tsec = current_security(); 2309 struct itimerval itimer; 2310 u32 osid, sid; 2311 int rc, i; 2312 2313 osid = tsec->osid; 2314 sid = tsec->sid; 2315 2316 if (sid == osid) 2317 return; 2318 2319 /* Check whether the new SID can inherit signal state from the old SID. 2320 * If not, clear itimers to avoid subsequent signal generation and 2321 * flush and unblock signals. 2322 * 2323 * This must occur _after_ the task SID has been updated so that any 2324 * kill done after the flush will be checked against the new SID. 2325 */ 2326 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); 2327 if (rc) { 2328 memset(&itimer, 0, sizeof itimer); 2329 for (i = 0; i < 3; i++) 2330 do_setitimer(i, &itimer, NULL); 2331 spin_lock_irq(¤t->sighand->siglock); 2332 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) { 2333 __flush_signals(current); 2334 flush_signal_handlers(current, 1); 2335 sigemptyset(¤t->blocked); 2336 } 2337 spin_unlock_irq(¤t->sighand->siglock); 2338 } 2339 2340 /* Wake up the parent if it is waiting so that it can recheck 2341 * wait permission to the new task SID. */ 2342 read_lock(&tasklist_lock); 2343 __wake_up_parent(current, current->real_parent); 2344 read_unlock(&tasklist_lock); 2345} 2346 2347/* superblock security operations */ 2348 2349static int selinux_sb_alloc_security(struct super_block *sb) 2350{ 2351 return superblock_alloc_security(sb); 2352} 2353 2354static void selinux_sb_free_security(struct super_block *sb) 2355{ 2356 superblock_free_security(sb); 2357} 2358 2359static inline int match_prefix(char *prefix, int plen, char *option, int olen) 2360{ 2361 if (plen > olen) 2362 return 0; 2363 2364 return !memcmp(prefix, option, plen); 2365} 2366 2367static inline int selinux_option(char *option, int len) 2368{ 2369 return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) || 2370 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) || 2371 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) || 2372 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) || 2373 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len)); 2374} 2375 2376static inline void take_option(char **to, char *from, int *first, int len) 2377{ 2378 if (!*first) { 2379 **to = ','; 2380 *to += 1; 2381 } else 2382 *first = 0; 2383 memcpy(*to, from, len); 2384 *to += len; 2385} 2386 2387static inline void take_selinux_option(char **to, char *from, int *first, 2388 int len) 2389{ 2390 int current_size = 0; 2391 2392 if (!*first) { 2393 **to = '|'; 2394 *to += 1; 2395 } else 2396 *first = 0; 2397 2398 while (current_size < len) { 2399 if (*from != '"') { 2400 **to = *from; 2401 *to += 1; 2402 } 2403 from += 1; 2404 current_size += 1; 2405 } 2406} 2407 2408static int selinux_sb_copy_data(char *orig, char *copy) 2409{ 2410 int fnosec, fsec, rc = 0; 2411 char *in_save, *in_curr, *in_end; 2412 char *sec_curr, *nosec_save, *nosec; 2413 int open_quote = 0; 2414 2415 in_curr = orig; 2416 sec_curr = copy; 2417 2418 nosec = (char *)get_zeroed_page(GFP_KERNEL); 2419 if (!nosec) { 2420 rc = -ENOMEM; 2421 goto out; 2422 } 2423 2424 nosec_save = nosec; 2425 fnosec = fsec = 1; 2426 in_save = in_end = orig; 2427 2428 do { 2429 if (*in_end == '"') 2430 open_quote = !open_quote; 2431 if ((*in_end == ',' && open_quote == 0) || 2432 *in_end == '\0') { 2433 int len = in_end - in_curr; 2434 2435 if (selinux_option(in_curr, len)) 2436 take_selinux_option(&sec_curr, in_curr, &fsec, len); 2437 else 2438 take_option(&nosec, in_curr, &fnosec, len); 2439 2440 in_curr = in_end + 1; 2441 } 2442 } while (*in_end++); 2443 2444 strcpy(in_save, nosec_save); 2445 free_page((unsigned long)nosec_save); 2446out: 2447 return rc; 2448} 2449 2450static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data) 2451{ 2452 const struct cred *cred = current_cred(); 2453 struct common_audit_data ad; 2454 int rc; 2455 2456 rc = superblock_doinit(sb, data); 2457 if (rc) 2458 return rc; 2459 2460 /* Allow all mounts performed by the kernel */ 2461 if (flags & MS_KERNMOUNT) 2462 return 0; 2463 2464 COMMON_AUDIT_DATA_INIT(&ad, FS); 2465 ad.u.fs.path.dentry = sb->s_root; 2466 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad); 2467} 2468 2469static int selinux_sb_statfs(struct dentry *dentry) 2470{ 2471 const struct cred *cred = current_cred(); 2472 struct common_audit_data ad; 2473 2474 COMMON_AUDIT_DATA_INIT(&ad, FS); 2475 ad.u.fs.path.dentry = dentry->d_sb->s_root; 2476 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); 2477} 2478 2479static int selinux_mount(char *dev_name, 2480 struct path *path, 2481 char *type, 2482 unsigned long flags, 2483 void *data) 2484{ 2485 const struct cred *cred = current_cred(); 2486 2487 if (flags & MS_REMOUNT) 2488 return superblock_has_perm(cred, path->mnt->mnt_sb, 2489 FILESYSTEM__REMOUNT, NULL); 2490 else 2491 return dentry_has_perm(cred, path->mnt, path->dentry, 2492 FILE__MOUNTON); 2493} 2494 2495static int selinux_umount(struct vfsmount *mnt, int flags) 2496{ 2497 const struct cred *cred = current_cred(); 2498 2499 return superblock_has_perm(cred, mnt->mnt_sb, 2500 FILESYSTEM__UNMOUNT, NULL); 2501} 2502 2503/* inode security operations */ 2504 2505static int selinux_inode_alloc_security(struct inode *inode) 2506{ 2507 return inode_alloc_security(inode); 2508} 2509 2510static void selinux_inode_free_security(struct inode *inode) 2511{ 2512 inode_free_security(inode); 2513} 2514 2515static int selinux_inode_init_security(struct inode *inode, struct inode *dir, 2516 char **name, void **value, 2517 size_t *len) 2518{ 2519 const struct task_security_struct *tsec = current_security(); 2520 struct inode_security_struct *dsec; 2521 struct superblock_security_struct *sbsec; 2522 u32 sid, newsid, clen; 2523 int rc; 2524 char *namep = NULL, *context; 2525 2526 dsec = dir->i_security; 2527 sbsec = dir->i_sb->s_security; 2528 2529 sid = tsec->sid; 2530 newsid = tsec->create_sid; 2531 2532 if ((sbsec->flags & SE_SBINITIALIZED) && 2533 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) 2534 newsid = sbsec->mntpoint_sid; 2535 else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) { 2536 rc = security_transition_sid(sid, dsec->sid, 2537 inode_mode_to_security_class(inode->i_mode), 2538 &newsid); 2539 if (rc) { 2540 printk(KERN_WARNING "%s: " 2541 "security_transition_sid failed, rc=%d (dev=%s " 2542 "ino=%ld)\n", 2543 __func__, 2544 -rc, inode->i_sb->s_id, inode->i_ino); 2545 return rc; 2546 } 2547 } 2548 2549 /* Possibly defer initialization to selinux_complete_init. */ 2550 if (sbsec->flags & SE_SBINITIALIZED) { 2551 struct inode_security_struct *isec = inode->i_security; 2552 isec->sclass = inode_mode_to_security_class(inode->i_mode); 2553 isec->sid = newsid; 2554 isec->initialized = 1; 2555 } 2556 2557 if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP)) 2558 return -EOPNOTSUPP; 2559 2560 if (name) { 2561 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS); 2562 if (!namep) 2563 return -ENOMEM; 2564 *name = namep; 2565 } 2566 2567 if (value && len) { 2568 rc = security_sid_to_context_force(newsid, &context, &clen); 2569 if (rc) { 2570 kfree(namep); 2571 return rc; 2572 } 2573 *value = context; 2574 *len = clen; 2575 } 2576 2577 return 0; 2578} 2579 2580static int selinux_inode_create(struct inode *dir, struct dentry *dentry, int mask) 2581{ 2582 return may_create(dir, dentry, SECCLASS_FILE); 2583} 2584 2585static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) 2586{ 2587 return may_link(dir, old_dentry, MAY_LINK); 2588} 2589 2590static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) 2591{ 2592 return may_link(dir, dentry, MAY_UNLINK); 2593} 2594 2595static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) 2596{ 2597 return may_create(dir, dentry, SECCLASS_LNK_FILE); 2598} 2599 2600static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, int mask) 2601{ 2602 return may_create(dir, dentry, SECCLASS_DIR); 2603} 2604 2605static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) 2606{ 2607 return may_link(dir, dentry, MAY_RMDIR); 2608} 2609 2610static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) 2611{ 2612 return may_create(dir, dentry, inode_mode_to_security_class(mode)); 2613} 2614 2615static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, 2616 struct inode *new_inode, struct dentry *new_dentry) 2617{ 2618 return may_rename(old_inode, old_dentry, new_inode, new_dentry); 2619} 2620 2621static int selinux_inode_readlink(struct dentry *dentry) 2622{ 2623 const struct cred *cred = current_cred(); 2624 2625 return dentry_has_perm(cred, NULL, dentry, FILE__READ); 2626} 2627 2628static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata) 2629{ 2630 const struct cred *cred = current_cred(); 2631 2632 return dentry_has_perm(cred, NULL, dentry, FILE__READ); 2633} 2634 2635static int selinux_inode_permission(struct inode *inode, int mask) 2636{ 2637 const struct cred *cred = current_cred(); 2638 struct common_audit_data ad; 2639 u32 perms; 2640 bool from_access; 2641 2642 from_access = mask & MAY_ACCESS; 2643 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); 2644 2645 /* No permission to check. Existence test. */ 2646 if (!mask) 2647 return 0; 2648 2649 COMMON_AUDIT_DATA_INIT(&ad, FS); 2650 ad.u.fs.inode = inode; 2651 2652 if (from_access) 2653 ad.selinux_audit_data.auditdeny |= FILE__AUDIT_ACCESS; 2654 2655 perms = file_mask_to_av(inode->i_mode, mask); 2656 2657 return inode_has_perm(cred, inode, perms, &ad); 2658} 2659 2660static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) 2661{ 2662 const struct cred *cred = current_cred(); 2663 unsigned int ia_valid = iattr->ia_valid; 2664 2665 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ 2666 if (ia_valid & ATTR_FORCE) { 2667 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | 2668 ATTR_FORCE); 2669 if (!ia_valid) 2670 return 0; 2671 } 2672 2673 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | 2674 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) 2675 return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR); 2676 2677 return dentry_has_perm(cred, NULL, dentry, FILE__WRITE); 2678} 2679 2680static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) 2681{ 2682 const struct cred *cred = current_cred(); 2683 2684 return dentry_has_perm(cred, mnt, dentry, FILE__GETATTR); 2685} 2686 2687static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name) 2688{ 2689 const struct cred *cred = current_cred(); 2690 2691 if (!strncmp(name, XATTR_SECURITY_PREFIX, 2692 sizeof XATTR_SECURITY_PREFIX - 1)) { 2693 if (!strcmp(name, XATTR_NAME_CAPS)) { 2694 if (!capable(CAP_SETFCAP)) 2695 return -EPERM; 2696 } else if (!capable(CAP_SYS_ADMIN)) { 2697 /* A different attribute in the security namespace. 2698 Restrict to administrator. */ 2699 return -EPERM; 2700 } 2701 } 2702 2703 /* Not an attribute we recognize, so just check the 2704 ordinary setattr permission. */ 2705 return dentry_has_perm(cred, NULL, dentry, FILE__SETATTR); 2706} 2707 2708static int selinux_inode_setxattr(struct dentry *dentry, const char *name, 2709 const void *value, size_t size, int flags) 2710{ 2711 struct inode *inode = dentry->d_inode; 2712 struct inode_security_struct *isec = inode->i_security; 2713 struct superblock_security_struct *sbsec; 2714 struct common_audit_data ad; 2715 u32 newsid, sid = current_sid(); 2716 int rc = 0; 2717 2718 if (strcmp(name, XATTR_NAME_SELINUX)) 2719 return selinux_inode_setotherxattr(dentry, name); 2720 2721 sbsec = inode->i_sb->s_security; 2722 if (!(sbsec->flags & SE_SBLABELSUPP)) 2723 return -EOPNOTSUPP; 2724 2725 if (!is_owner_or_cap(inode)) 2726 return -EPERM; 2727 2728 COMMON_AUDIT_DATA_INIT(&ad, FS); 2729 ad.u.fs.path.dentry = dentry; 2730 2731 rc = avc_has_perm(sid, isec->sid, isec->sclass, 2732 FILE__RELABELFROM, &ad); 2733 if (rc) 2734 return rc; 2735 2736 rc = security_context_to_sid(value, size, &newsid); 2737 if (rc == -EINVAL) { 2738 if (!capable(CAP_MAC_ADMIN)) 2739 return rc; 2740 rc = security_context_to_sid_force(value, size, &newsid); 2741 } 2742 if (rc) 2743 return rc; 2744 2745 rc = avc_has_perm(sid, newsid, isec->sclass, 2746 FILE__RELABELTO, &ad); 2747 if (rc) 2748 return rc; 2749 2750 rc = security_validate_transition(isec->sid, newsid, sid, 2751 isec->sclass); 2752 if (rc) 2753 return rc; 2754 2755 return avc_has_perm(newsid, 2756 sbsec->sid, 2757 SECCLASS_FILESYSTEM, 2758 FILESYSTEM__ASSOCIATE, 2759 &ad); 2760} 2761 2762static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, 2763 const void *value, size_t size, 2764 int flags) 2765{ 2766 struct inode *inode = dentry->d_inode; 2767 struct inode_security_struct *isec = inode->i_security; 2768 u32 newsid; 2769 int rc; 2770 2771 if (strcmp(name, XATTR_NAME_SELINUX)) { 2772 /* Not an attribute we recognize, so nothing to do. */ 2773 return; 2774 } 2775 2776 rc = security_context_to_sid_force(value, size, &newsid); 2777 if (rc) { 2778 printk(KERN_ERR "SELinux: unable to map context to SID" 2779 "for (%s, %lu), rc=%d\n", 2780 inode->i_sb->s_id, inode->i_ino, -rc); 2781 return; 2782 } 2783 2784 isec->sid = newsid; 2785 return; 2786} 2787 2788static int selinux_inode_getxattr(struct dentry *dentry, const char *name) 2789{ 2790 const struct cred *cred = current_cred(); 2791 2792 return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR); 2793} 2794 2795static int selinux_inode_listxattr(struct dentry *dentry) 2796{ 2797 const struct cred *cred = current_cred(); 2798 2799 return dentry_has_perm(cred, NULL, dentry, FILE__GETATTR); 2800} 2801 2802static int selinux_inode_removexattr(struct dentry *dentry, const char *name) 2803{ 2804 if (strcmp(name, XATTR_NAME_SELINUX)) 2805 return selinux_inode_setotherxattr(dentry, name); 2806 2807 /* No one is allowed to remove a SELinux security label. 2808 You can change the label, but all data must be labeled. */ 2809 return -EACCES; 2810} 2811 2812/* 2813 * Copy the inode security context value to the user. 2814 * 2815 * Permission check is handled by selinux_inode_getxattr hook. 2816 */ 2817static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc) 2818{ 2819 u32 size; 2820 int error; 2821 char *context = NULL; 2822 struct inode_security_struct *isec = inode->i_security; 2823 2824 if (strcmp(name, XATTR_SELINUX_SUFFIX)) 2825 return -EOPNOTSUPP; 2826 2827 /* 2828 * If the caller has CAP_MAC_ADMIN, then get the raw context 2829 * value even if it is not defined by current policy; otherwise, 2830 * use the in-core value under current policy. 2831 * Use the non-auditing forms of the permission checks since 2832 * getxattr may be called by unprivileged processes commonly 2833 * and lack of permission just means that we fall back to the 2834 * in-core context value, not a denial. 2835 */ 2836 error = selinux_capable(current, current_cred(), CAP_MAC_ADMIN, 2837 SECURITY_CAP_NOAUDIT); 2838 if (!error) 2839 error = security_sid_to_context_force(isec->sid, &context, 2840 &size); 2841 else 2842 error = security_sid_to_context(isec->sid, &context, &size); 2843 if (error) 2844 return error; 2845 error = size; 2846 if (alloc) { 2847 *buffer = context; 2848 goto out_nofree; 2849 } 2850 kfree(context); 2851out_nofree: 2852 return error; 2853} 2854 2855static int selinux_inode_setsecurity(struct inode *inode, const char *name, 2856 const void *value, size_t size, int flags) 2857{ 2858 struct inode_security_struct *isec = inode->i_security; 2859 u32 newsid; 2860 int rc; 2861 2862 if (strcmp(name, XATTR_SELINUX_SUFFIX)) 2863 return -EOPNOTSUPP; 2864 2865 if (!value || !size) 2866 return -EACCES; 2867 2868 rc = security_context_to_sid((void *)value, size, &newsid); 2869 if (rc) 2870 return rc; 2871 2872 isec->sid = newsid; 2873 isec->initialized = 1; 2874 return 0; 2875} 2876 2877static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) 2878{ 2879 const int len = sizeof(XATTR_NAME_SELINUX); 2880 if (buffer && len <= buffer_size) 2881 memcpy(buffer, XATTR_NAME_SELINUX, len); 2882 return len; 2883} 2884 2885static void selinux_inode_getsecid(const struct inode *inode, u32 *secid) 2886{ 2887 struct inode_security_struct *isec = inode->i_security; 2888 *secid = isec->sid; 2889} 2890 2891/* file security operations */ 2892 2893static int selinux_revalidate_file_permission(struct file *file, int mask) 2894{ 2895 const struct cred *cred = current_cred(); 2896 struct inode *inode = file->f_path.dentry->d_inode; 2897 2898 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ 2899 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) 2900 mask |= MAY_APPEND; 2901 2902 return file_has_perm(cred, file, 2903 file_mask_to_av(inode->i_mode, mask)); 2904} 2905 2906static int selinux_file_permission(struct file *file, int mask) 2907{ 2908 struct inode *inode = file->f_path.dentry->d_inode; 2909 struct file_security_struct *fsec = file->f_security; 2910 struct inode_security_struct *isec = inode->i_security; 2911 u32 sid = current_sid(); 2912 2913 if (!mask) 2914 /* No permission to check. Existence test. */ 2915 return 0; 2916 2917 if (sid == fsec->sid && fsec->isid == isec->sid && 2918 fsec->pseqno == avc_policy_seqno()) 2919 /* No change since dentry_open check. */ 2920 return 0; 2921 2922 return selinux_revalidate_file_permission(file, mask); 2923} 2924 2925static int selinux_file_alloc_security(struct file *file) 2926{ 2927 return file_alloc_security(file); 2928} 2929 2930static void selinux_file_free_security(struct file *file) 2931{ 2932 file_free_security(file); 2933} 2934 2935static int selinux_file_ioctl(struct file *file, unsigned int cmd, 2936 unsigned long arg) 2937{ 2938 const struct cred *cred = current_cred(); 2939 u32 av = 0; 2940 2941 if (_IOC_DIR(cmd) & _IOC_WRITE) 2942 av |= FILE__WRITE; 2943 if (_IOC_DIR(cmd) & _IOC_READ) 2944 av |= FILE__READ; 2945 if (!av) 2946 av = FILE__IOCTL; 2947 2948 return file_has_perm(cred, file, av); 2949} 2950 2951static int default_noexec; 2952 2953static int file_map_prot_check(struct file *file, unsigned long prot, int shared) 2954{ 2955 const struct cred *cred = current_cred(); 2956 int rc = 0; 2957 2958 if (default_noexec && 2959 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) { 2960 /* 2961 * We are making executable an anonymous mapping or a 2962 * private file mapping that will also be writable. 2963 * This has an additional check. 2964 */ 2965 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM); 2966 if (rc) 2967 goto error; 2968 } 2969 2970 if (file) { 2971 /* read access is always possible with a mapping */ 2972 u32 av = FILE__READ; 2973 2974 /* write access only matters if the mapping is shared */ 2975 if (shared && (prot & PROT_WRITE)) 2976 av |= FILE__WRITE; 2977 2978 if (prot & PROT_EXEC) 2979 av |= FILE__EXECUTE; 2980 2981 return file_has_perm(cred, file, av); 2982 } 2983 2984error: 2985 return rc; 2986} 2987 2988static int selinux_file_mmap(struct file *file, unsigned long reqprot, 2989 unsigned long prot, unsigned long flags, 2990 unsigned long addr, unsigned long addr_only) 2991{ 2992 int rc = 0; 2993 u32 sid = current_sid(); 2994 2995 /* 2996 * notice that we are intentionally putting the SELinux check before 2997 * the secondary cap_file_mmap check. This is such a likely attempt 2998 * at bad behaviour/exploit that we always want to get the AVC, even 2999 * if DAC would have also denied the operation. 3000 */ 3001 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) { 3002 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, 3003 MEMPROTECT__MMAP_ZERO, NULL); 3004 if (rc) 3005 return rc; 3006 } 3007 3008 /* do DAC check on address space usage */ 3009 rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only); 3010 if (rc || addr_only) 3011 return rc; 3012 3013 if (selinux_checkreqprot) 3014 prot = reqprot; 3015 3016 return file_map_prot_check(file, prot, 3017 (flags & MAP_TYPE) == MAP_SHARED); 3018} 3019 3020static int selinux_file_mprotect(struct vm_area_struct *vma, 3021 unsigned long reqprot, 3022 unsigned long prot) 3023{ 3024 const struct cred *cred = current_cred(); 3025 3026 if (selinux_checkreqprot) 3027 prot = reqprot; 3028 3029 if (default_noexec && 3030 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { 3031 int rc = 0; 3032 if (vma->vm_start >= vma->vm_mm->start_brk && 3033 vma->vm_end <= vma->vm_mm->brk) { 3034 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP); 3035 } else if (!vma->vm_file && 3036 vma->vm_start <= vma->vm_mm->start_stack && 3037 vma->vm_end >= vma->vm_mm->start_stack) { 3038 rc = current_has_perm(current, PROCESS__EXECSTACK); 3039 } else if (vma->vm_file && vma->anon_vma) { 3040 /* 3041 * We are making executable a file mapping that has 3042 * had some COW done. Since pages might have been 3043 * written, check ability to execute the possibly 3044 * modified content. This typically should only 3045 * occur for text relocations. 3046 */ 3047 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD); 3048 } 3049 if (rc) 3050 return rc; 3051 } 3052 3053 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED); 3054} 3055 3056static int selinux_file_lock(struct file *file, unsigned int cmd) 3057{ 3058 const struct cred *cred = current_cred(); 3059 3060 return file_has_perm(cred, file, FILE__LOCK); 3061} 3062 3063static int selinux_file_fcntl(struct file *file, unsigned int cmd, 3064 unsigned long arg) 3065{ 3066 const struct cred *cred = current_cred(); 3067 int err = 0; 3068 3069 switch (cmd) { 3070 case F_SETFL: 3071 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) { 3072 err = -EINVAL; 3073 break; 3074 } 3075 3076 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) { 3077 err = file_has_perm(cred, file, FILE__WRITE); 3078 break; 3079 } 3080 /* fall through */ 3081 case F_SETOWN: 3082 case F_SETSIG: 3083 case F_GETFL: 3084 case F_GETOWN: 3085 case F_GETSIG: 3086 /* Just check FD__USE permission */ 3087 err = file_has_perm(cred, file, 0); 3088 break; 3089 case F_GETLK: 3090 case F_SETLK: 3091 case F_SETLKW: 3092#if BITS_PER_LONG == 32 3093 case F_GETLK64: 3094 case F_SETLK64: 3095 case F_SETLKW64: 3096#endif 3097 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) { 3098 err = -EINVAL; 3099 break; 3100 } 3101 err = file_has_perm(cred, file, FILE__LOCK); 3102 break; 3103 } 3104 3105 return err; 3106} 3107 3108static int selinux_file_set_fowner(struct file *file) 3109{ 3110 struct file_security_struct *fsec; 3111 3112 fsec = file->f_security; 3113 fsec->fown_sid = current_sid(); 3114 3115 return 0; 3116} 3117 3118static int selinux_file_send_sigiotask(struct task_struct *tsk, 3119 struct fown_struct *fown, int signum) 3120{ 3121 struct file *file; 3122 u32 sid = task_sid(tsk); 3123 u32 perm; 3124 struct file_security_struct *fsec; 3125 3126 /* struct fown_struct is never outside the context of a struct file */ 3127 file = container_of(fown, struct file, f_owner); 3128 3129 fsec = file->f_security; 3130 3131 if (!signum) 3132 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */ 3133 else 3134 perm = signal_to_av(signum); 3135 3136 return avc_has_perm(fsec->fown_sid, sid, 3137 SECCLASS_PROCESS, perm, NULL); 3138} 3139 3140static int selinux_file_receive(struct file *file) 3141{ 3142 const struct cred *cred = current_cred(); 3143 3144 return file_has_perm(cred, file, file_to_av(file)); 3145} 3146 3147static int selinux_dentry_open(struct file *file, const struct cred *cred) 3148{ 3149 struct file_security_struct *fsec; 3150 struct inode *inode; 3151 struct inode_security_struct *isec; 3152 3153 inode = file->f_path.dentry->d_inode; 3154 fsec = file->f_security; 3155 isec = inode->i_security; 3156 /* 3157 * Save inode label and policy sequence number 3158 * at open-time so that selinux_file_permission 3159 * can determine whether revalidation is necessary. 3160 * Task label is already saved in the file security 3161 * struct as its SID. 3162 */ 3163 fsec->isid = isec->sid; 3164 fsec->pseqno = avc_policy_seqno(); 3165 /* 3166 * Since the inode label or policy seqno may have changed 3167 * between the selinux_inode_permission check and the saving 3168 * of state above, recheck that access is still permitted. 3169 * Otherwise, access might never be revalidated against the 3170 * new inode label or new policy. 3171 * This check is not redundant - do not remove. 3172 */ 3173 return inode_has_perm(cred, inode, open_file_to_av(file), NULL); 3174} 3175 3176/* task security operations */ 3177 3178static int selinux_task_create(unsigned long clone_flags) 3179{ 3180 return current_has_perm(current, PROCESS__FORK); 3181} 3182 3183/* 3184 * allocate the SELinux part of blank credentials 3185 */ 3186static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp) 3187{ 3188 struct task_security_struct *tsec; 3189 3190 tsec = kzalloc(sizeof(struct task_security_struct), gfp); 3191 if (!tsec) 3192 return -ENOMEM; 3193 3194 cred->security = tsec; 3195 return 0; 3196} 3197 3198/* 3199 * detach and free the LSM part of a set of credentials 3200 */ 3201static void selinux_cred_free(struct cred *cred) 3202{ 3203 struct task_security_struct *tsec = cred->security; 3204 3205 BUG_ON((unsigned long) cred->security < PAGE_SIZE); 3206 cred->security = (void *) 0x7UL; 3207 kfree(tsec); 3208} 3209 3210/* 3211 * prepare a new set of credentials for modification 3212 */ 3213static int selinux_cred_prepare(struct cred *new, const struct cred *old, 3214 gfp_t gfp) 3215{ 3216 const struct task_security_struct *old_tsec; 3217 struct task_security_struct *tsec; 3218 3219 old_tsec = old->security; 3220 3221 tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp); 3222 if (!tsec) 3223 return -ENOMEM; 3224 3225 new->security = tsec; 3226 return 0; 3227} 3228 3229/* 3230 * transfer the SELinux data to a blank set of creds 3231 */ 3232static void selinux_cred_transfer(struct cred *new, const struct cred *old) 3233{ 3234 const struct task_security_struct *old_tsec = old->security; 3235 struct task_security_struct *tsec = new->security; 3236 3237 *tsec = *old_tsec; 3238} 3239 3240/* 3241 * set the security data for a kernel service 3242 * - all the creation contexts are set to unlabelled 3243 */ 3244static int selinux_kernel_act_as(struct cred *new, u32 secid) 3245{ 3246 struct task_security_struct *tsec = new->security; 3247 u32 sid = current_sid(); 3248 int ret; 3249 3250 ret = avc_has_perm(sid, secid, 3251 SECCLASS_KERNEL_SERVICE, 3252 KERNEL_SERVICE__USE_AS_OVERRIDE, 3253 NULL); 3254 if (ret == 0) { 3255 tsec->sid = secid; 3256 tsec->create_sid = 0; 3257 tsec->keycreate_sid = 0; 3258 tsec->sockcreate_sid = 0; 3259 } 3260 return ret; 3261} 3262 3263/* 3264 * set the file creation context in a security record to the same as the 3265 * objective context of the specified inode 3266 */ 3267static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode) 3268{ 3269 struct inode_security_struct *isec = inode->i_security; 3270 struct task_security_struct *tsec = new->security; 3271 u32 sid = current_sid(); 3272 int ret; 3273 3274 ret = avc_has_perm(sid, isec->sid, 3275 SECCLASS_KERNEL_SERVICE, 3276 KERNEL_SERVICE__CREATE_FILES_AS, 3277 NULL); 3278 3279 if (ret == 0) 3280 tsec->create_sid = isec->sid; 3281 return ret; 3282} 3283 3284static int selinux_kernel_module_request(char *kmod_name) 3285{ 3286 u32 sid; 3287 struct common_audit_data ad; 3288 3289 sid = task_sid(current); 3290 3291 COMMON_AUDIT_DATA_INIT(&ad, KMOD); 3292 ad.u.kmod_name = kmod_name; 3293 3294 return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM, 3295 SYSTEM__MODULE_REQUEST, &ad); 3296} 3297 3298static int selinux_task_setpgid(struct task_struct *p, pid_t pgid) 3299{ 3300 return current_has_perm(p, PROCESS__SETPGID); 3301} 3302 3303static int selinux_task_getpgid(struct task_struct *p) 3304{ 3305 return current_has_perm(p, PROCESS__GETPGID); 3306} 3307 3308static int selinux_task_getsid(struct task_struct *p) 3309{ 3310 return current_has_perm(p, PROCESS__GETSESSION); 3311} 3312 3313static void selinux_task_getsecid(struct task_struct *p, u32 *secid) 3314{ 3315 *secid = task_sid(p); 3316} 3317 3318static int selinux_task_setnice(struct task_struct *p, int nice) 3319{ 3320 int rc; 3321 3322 rc = cap_task_setnice(p, nice); 3323 if (rc) 3324 return rc; 3325 3326 return current_has_perm(p, PROCESS__SETSCHED); 3327} 3328 3329static int selinux_task_setioprio(struct task_struct *p, int ioprio) 3330{ 3331 int rc; 3332 3333 rc = cap_task_setioprio(p, ioprio); 3334 if (rc) 3335 return rc; 3336 3337 return current_has_perm(p, PROCESS__SETSCHED); 3338} 3339 3340static int selinux_task_getioprio(struct task_struct *p) 3341{ 3342 return current_has_perm(p, PROCESS__GETSCHED); 3343} 3344 3345static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource, 3346 struct rlimit *new_rlim) 3347{ 3348 struct rlimit *old_rlim = p->signal->rlim + resource; 3349 3350 /* Control the ability to change the hard limit (whether 3351 lowering or raising it), so that the hard limit can 3352 later be used as a safe reset point for the soft limit 3353 upon context transitions. See selinux_bprm_committing_creds. */ 3354 if (old_rlim->rlim_max != new_rlim->rlim_max) 3355 return current_has_perm(p, PROCESS__SETRLIMIT); 3356 3357 return 0; 3358} 3359 3360static int selinux_task_setscheduler(struct task_struct *p, int policy, struct sched_param *lp) 3361{ 3362 int rc; 3363 3364 rc = cap_task_setscheduler(p, policy, lp); 3365 if (rc) 3366 return rc; 3367 3368 return current_has_perm(p, PROCESS__SETSCHED); 3369} 3370 3371static int selinux_task_getscheduler(struct task_struct *p) 3372{ 3373 return current_has_perm(p, PROCESS__GETSCHED); 3374} 3375 3376static int selinux_task_movememory(struct task_struct *p) 3377{ 3378 return current_has_perm(p, PROCESS__SETSCHED); 3379} 3380 3381static int selinux_task_kill(struct task_struct *p, struct siginfo *info, 3382 int sig, u32 secid) 3383{ 3384 u32 perm; 3385 int rc; 3386 3387 if (!sig) 3388 perm = PROCESS__SIGNULL; /* null signal; existence test */ 3389 else 3390 perm = signal_to_av(sig); 3391 if (secid) 3392 rc = avc_has_perm(secid, task_sid(p), 3393 SECCLASS_PROCESS, perm, NULL); 3394 else 3395 rc = current_has_perm(p, perm); 3396 return rc; 3397} 3398 3399static int selinux_task_wait(struct task_struct *p) 3400{ 3401 return task_has_perm(p, current, PROCESS__SIGCHLD); 3402} 3403 3404static void selinux_task_to_inode(struct task_struct *p, 3405 struct inode *inode) 3406{ 3407 struct inode_security_struct *isec = inode->i_security; 3408 u32 sid = task_sid(p); 3409 3410 isec->sid = sid; 3411 isec->initialized = 1; 3412} 3413 3414/* Returns error only if unable to parse addresses */ 3415static int selinux_parse_skb_ipv4(struct sk_buff *skb, 3416 struct common_audit_data *ad, u8 *proto) 3417{ 3418 int offset, ihlen, ret = -EINVAL; 3419 struct iphdr _iph, *ih; 3420 3421 offset = skb_network_offset(skb); 3422 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph); 3423 if (ih == NULL) 3424 goto out; 3425 3426 ihlen = ih->ihl * 4; 3427 if (ihlen < sizeof(_iph)) 3428 goto out; 3429 3430 ad->u.net.v4info.saddr = ih->saddr; 3431 ad->u.net.v4info.daddr = ih->daddr; 3432 ret = 0; 3433 3434 if (proto) 3435 *proto = ih->protocol; 3436 3437 switch (ih->protocol) { 3438 case IPPROTO_TCP: { 3439 struct tcphdr _tcph, *th; 3440 3441 if (ntohs(ih->frag_off) & IP_OFFSET) 3442 break; 3443 3444 offset += ihlen; 3445 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); 3446 if (th == NULL) 3447 break; 3448 3449 ad->u.net.sport = th->source; 3450 ad->u.net.dport = th->dest; 3451 break; 3452 } 3453 3454 case IPPROTO_UDP: { 3455 struct udphdr _udph, *uh; 3456 3457 if (ntohs(ih->frag_off) & IP_OFFSET) 3458 break; 3459 3460 offset += ihlen; 3461 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); 3462 if (uh == NULL) 3463 break; 3464 3465 ad->u.net.sport = uh->source; 3466 ad->u.net.dport = uh->dest; 3467 break; 3468 } 3469 3470 case IPPROTO_DCCP: { 3471 struct dccp_hdr _dccph, *dh; 3472 3473 if (ntohs(ih->frag_off) & IP_OFFSET) 3474 break; 3475 3476 offset += ihlen; 3477 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); 3478 if (dh == NULL) 3479 break; 3480 3481 ad->u.net.sport = dh->dccph_sport; 3482 ad->u.net.dport = dh->dccph_dport; 3483 break; 3484 } 3485 3486 default: 3487 break; 3488 } 3489out: 3490 return ret; 3491} 3492 3493#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 3494 3495/* Returns error only if unable to parse addresses */ 3496static int selinux_parse_skb_ipv6(struct sk_buff *skb, 3497 struct common_audit_data *ad, u8 *proto) 3498{ 3499 u8 nexthdr; 3500 int ret = -EINVAL, offset; 3501 struct ipv6hdr _ipv6h, *ip6; 3502 3503 offset = skb_network_offset(skb); 3504 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); 3505 if (ip6 == NULL) 3506 goto out; 3507 3508 ipv6_addr_copy(&ad->u.net.v6info.saddr, &ip6->saddr); 3509 ipv6_addr_copy(&ad->u.net.v6info.daddr, &ip6->daddr); 3510 ret = 0; 3511 3512 nexthdr = ip6->nexthdr; 3513 offset += sizeof(_ipv6h); 3514 offset = ipv6_skip_exthdr(skb, offset, &nexthdr); 3515 if (offset < 0) 3516 goto out; 3517 3518 if (proto) 3519 *proto = nexthdr; 3520 3521 switch (nexthdr) { 3522 case IPPROTO_TCP: { 3523 struct tcphdr _tcph, *th; 3524 3525 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); 3526 if (th == NULL) 3527 break; 3528 3529 ad->u.net.sport = th->source; 3530 ad->u.net.dport = th->dest; 3531 break; 3532 } 3533 3534 case IPPROTO_UDP: { 3535 struct udphdr _udph, *uh; 3536 3537 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); 3538 if (uh == NULL) 3539 break; 3540 3541 ad->u.net.sport = uh->source; 3542 ad->u.net.dport = uh->dest; 3543 break; 3544 } 3545 3546 case IPPROTO_DCCP: { 3547 struct dccp_hdr _dccph, *dh; 3548 3549 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); 3550 if (dh == NULL) 3551 break; 3552 3553 ad->u.net.sport = dh->dccph_sport; 3554 ad->u.net.dport = dh->dccph_dport; 3555 break; 3556 } 3557 3558 /* includes fragments */ 3559 default: 3560 break; 3561 } 3562out: 3563 return ret; 3564} 3565 3566#endif /* IPV6 */ 3567 3568static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad, 3569 char **_addrp, int src, u8 *proto) 3570{ 3571 char *addrp; 3572 int ret; 3573 3574 switch (ad->u.net.family) { 3575 case PF_INET: 3576 ret = selinux_parse_skb_ipv4(skb, ad, proto); 3577 if (ret) 3578 goto parse_error; 3579 addrp = (char *)(src ? &ad->u.net.v4info.saddr : 3580 &ad->u.net.v4info.daddr); 3581 goto okay; 3582 3583#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 3584 case PF_INET6: 3585 ret = selinux_parse_skb_ipv6(skb, ad, proto); 3586 if (ret) 3587 goto parse_error; 3588 addrp = (char *)(src ? &ad->u.net.v6info.saddr : 3589 &ad->u.net.v6info.daddr); 3590 goto okay; 3591#endif /* IPV6 */ 3592 default: 3593 addrp = NULL; 3594 goto okay; 3595 } 3596 3597parse_error: 3598 printk(KERN_WARNING 3599 "SELinux: failure in selinux_parse_skb()," 3600 " unable to parse packet\n"); 3601 return ret; 3602 3603okay: 3604 if (_addrp) 3605 *_addrp = addrp; 3606 return 0; 3607} 3608 3609/** 3610 * selinux_skb_peerlbl_sid - Determine the peer label of a packet 3611 * @skb: the packet 3612 * @family: protocol family 3613 * @sid: the packet's peer label SID 3614 * 3615 * Description: 3616 * Check the various different forms of network peer labeling and determine 3617 * the peer label/SID for the packet; most of the magic actually occurs in 3618 * the security server function security_net_peersid_cmp(). The function 3619 * returns zero if the value in @sid is valid (although it may be SECSID_NULL) 3620 * or -EACCES if @sid is invalid due to inconsistencies with the different 3621 * peer labels. 3622 * 3623 */ 3624static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) 3625{ 3626 int err; 3627 u32 xfrm_sid; 3628 u32 nlbl_sid; 3629 u32 nlbl_type; 3630 3631 selinux_skb_xfrm_sid(skb, &xfrm_sid); 3632 selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid); 3633 3634 err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid); 3635 if (unlikely(err)) { 3636 printk(KERN_WARNING 3637 "SELinux: failure in selinux_skb_peerlbl_sid()," 3638 " unable to determine packet's peer label\n"); 3639 return -EACCES; 3640 } 3641 3642 return 0; 3643} 3644 3645/* socket security operations */ 3646 3647static u32 socket_sockcreate_sid(const struct task_security_struct *tsec) 3648{ 3649 return tsec->sockcreate_sid ? : tsec->sid; 3650} 3651 3652static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms) 3653{ 3654 struct sk_security_struct *sksec = sk->sk_security; 3655 struct common_audit_data ad; 3656 u32 tsid = task_sid(task); 3657 3658 if (sksec->sid == SECINITSID_KERNEL) 3659 return 0; 3660 3661 COMMON_AUDIT_DATA_INIT(&ad, NET); 3662 ad.u.net.sk = sk; 3663 3664 return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad); 3665} 3666 3667static int selinux_socket_create(int family, int type, 3668 int protocol, int kern) 3669{ 3670 const struct task_security_struct *tsec = current_security(); 3671 u32 newsid; 3672 u16 secclass; 3673 3674 if (kern) 3675 return 0; 3676 3677 newsid = socket_sockcreate_sid(tsec); 3678 secclass = socket_type_to_security_class(family, type, protocol); 3679 return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL); 3680} 3681 3682static int selinux_socket_post_create(struct socket *sock, int family, 3683 int type, int protocol, int kern) 3684{ 3685 const struct task_security_struct *tsec = current_security(); 3686 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security; 3687 struct sk_security_struct *sksec; 3688 int err = 0; 3689 3690 if (kern) 3691 isec->sid = SECINITSID_KERNEL; 3692 else 3693 isec->sid = socket_sockcreate_sid(tsec); 3694 3695 isec->sclass = socket_type_to_security_class(family, type, protocol); 3696 isec->initialized = 1; 3697 3698 if (sock->sk) { 3699 sksec = sock->sk->sk_security; 3700 sksec->sid = isec->sid; 3701 sksec->sclass = isec->sclass; 3702 err = selinux_netlbl_socket_post_create(sock->sk, family); 3703 } 3704 3705 return err; 3706} 3707 3708/* Range of port numbers used to automatically bind. 3709 Need to determine whether we should perform a name_bind 3710 permission check between the socket and the port number. */ 3711 3712static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) 3713{ 3714 struct sock *sk = sock->sk; 3715 u16 family; 3716 int err; 3717 3718 err = sock_has_perm(current, sk, SOCKET__BIND); 3719 if (err) 3720 goto out; 3721 3722 /* 3723 * If PF_INET or PF_INET6, check name_bind permission for the port. 3724 * Multiple address binding for SCTP is not supported yet: we just 3725 * check the first address now. 3726 */ 3727 family = sk->sk_family; 3728 if (family == PF_INET || family == PF_INET6) { 3729 char *addrp; 3730 struct sk_security_struct *sksec = sk->sk_security; 3731 struct common_audit_data ad; 3732 struct sockaddr_in *addr4 = NULL; 3733 struct sockaddr_in6 *addr6 = NULL; 3734 unsigned short snum; 3735 u32 sid, node_perm; 3736 3737 if (family == PF_INET) { 3738 addr4 = (struct sockaddr_in *)address; 3739 snum = ntohs(addr4->sin_port); 3740 addrp = (char *)&addr4->sin_addr.s_addr; 3741 } else { 3742 addr6 = (struct sockaddr_in6 *)address; 3743 snum = ntohs(addr6->sin6_port); 3744 addrp = (char *)&addr6->sin6_addr.s6_addr; 3745 } 3746 3747 if (snum) { 3748 int low, high; 3749 3750 inet_get_local_port_range(&low, &high); 3751 3752 if (snum < max(PROT_SOCK, low) || snum > high) { 3753 err = sel_netport_sid(sk->sk_protocol, 3754 snum, &sid); 3755 if (err) 3756 goto out; 3757 COMMON_AUDIT_DATA_INIT(&ad, NET); 3758 ad.u.net.sport = htons(snum); 3759 ad.u.net.family = family; 3760 err = avc_has_perm(sksec->sid, sid, 3761 sksec->sclass, 3762 SOCKET__NAME_BIND, &ad); 3763 if (err) 3764 goto out; 3765 } 3766 } 3767 3768 switch (sksec->sclass) { 3769 case SECCLASS_TCP_SOCKET: 3770 node_perm = TCP_SOCKET__NODE_BIND; 3771 break; 3772 3773 case SECCLASS_UDP_SOCKET: 3774 node_perm = UDP_SOCKET__NODE_BIND; 3775 break; 3776 3777 case SECCLASS_DCCP_SOCKET: 3778 node_perm = DCCP_SOCKET__NODE_BIND; 3779 break; 3780 3781 default: 3782 node_perm = RAWIP_SOCKET__NODE_BIND; 3783 break; 3784 } 3785 3786 err = sel_netnode_sid(addrp, family, &sid); 3787 if (err) 3788 goto out; 3789 3790 COMMON_AUDIT_DATA_INIT(&ad, NET); 3791 ad.u.net.sport = htons(snum); 3792 ad.u.net.family = family; 3793 3794 if (family == PF_INET) 3795 ad.u.net.v4info.saddr = addr4->sin_addr.s_addr; 3796 else 3797 ipv6_addr_copy(&ad.u.net.v6info.saddr, &addr6->sin6_addr); 3798 3799 err = avc_has_perm(sksec->sid, sid, 3800 sksec->sclass, node_perm, &ad); 3801 if (err) 3802 goto out; 3803 } 3804out: 3805 return err; 3806} 3807 3808static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen) 3809{ 3810 struct sock *sk = sock->sk; 3811 struct sk_security_struct *sksec = sk->sk_security; 3812 int err; 3813 3814 err = sock_has_perm(current, sk, SOCKET__CONNECT); 3815 if (err) 3816 return err; 3817 3818 /* 3819 * If a TCP or DCCP socket, check name_connect permission for the port. 3820 */ 3821 if (sksec->sclass == SECCLASS_TCP_SOCKET || 3822 sksec->sclass == SECCLASS_DCCP_SOCKET) { 3823 struct common_audit_data ad; 3824 struct sockaddr_in *addr4 = NULL; 3825 struct sockaddr_in6 *addr6 = NULL; 3826 unsigned short snum; 3827 u32 sid, perm; 3828 3829 if (sk->sk_family == PF_INET) { 3830 addr4 = (struct sockaddr_in *)address; 3831 if (addrlen < sizeof(struct sockaddr_in)) 3832 return -EINVAL; 3833 snum = ntohs(addr4->sin_port); 3834 } else { 3835 addr6 = (struct sockaddr_in6 *)address; 3836 if (addrlen < SIN6_LEN_RFC2133) 3837 return -EINVAL; 3838 snum = ntohs(addr6->sin6_port); 3839 } 3840 3841 err = sel_netport_sid(sk->sk_protocol, snum, &sid); 3842 if (err) 3843 goto out; 3844 3845 perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ? 3846 TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT; 3847 3848 COMMON_AUDIT_DATA_INIT(&ad, NET); 3849 ad.u.net.dport = htons(snum); 3850 ad.u.net.family = sk->sk_family; 3851 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad); 3852 if (err) 3853 goto out; 3854 } 3855 3856 err = selinux_netlbl_socket_connect(sk, address); 3857 3858out: 3859 return err; 3860} 3861 3862static int selinux_socket_listen(struct socket *sock, int backlog) 3863{ 3864 return sock_has_perm(current, sock->sk, SOCKET__LISTEN); 3865} 3866 3867static int selinux_socket_accept(struct socket *sock, struct socket *newsock) 3868{ 3869 int err; 3870 struct inode_security_struct *isec; 3871 struct inode_security_struct *newisec; 3872 3873 err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT); 3874 if (err) 3875 return err; 3876 3877 newisec = SOCK_INODE(newsock)->i_security; 3878 3879 isec = SOCK_INODE(sock)->i_security; 3880 newisec->sclass = isec->sclass; 3881 newisec->sid = isec->sid; 3882 newisec->initialized = 1; 3883 3884 return 0; 3885} 3886 3887static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg, 3888 int size) 3889{ 3890 return sock_has_perm(current, sock->sk, SOCKET__WRITE); 3891} 3892 3893static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg, 3894 int size, int flags) 3895{ 3896 return sock_has_perm(current, sock->sk, SOCKET__READ); 3897} 3898 3899static int selinux_socket_getsockname(struct socket *sock) 3900{ 3901 return sock_has_perm(current, sock->sk, SOCKET__GETATTR); 3902} 3903 3904static int selinux_socket_getpeername(struct socket *sock) 3905{ 3906 return sock_has_perm(current, sock->sk, SOCKET__GETATTR); 3907} 3908 3909static int selinux_socket_setsockopt(struct socket *sock, int level, int optname) 3910{ 3911 int err; 3912 3913 err = sock_has_perm(current, sock->sk, SOCKET__SETOPT); 3914 if (err) 3915 return err; 3916 3917 return selinux_netlbl_socket_setsockopt(sock, level, optname); 3918} 3919 3920static int selinux_socket_getsockopt(struct socket *sock, int level, 3921 int optname) 3922{ 3923 return sock_has_perm(current, sock->sk, SOCKET__GETOPT); 3924} 3925 3926static int selinux_socket_shutdown(struct socket *sock, int how) 3927{ 3928 return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN); 3929} 3930 3931static int selinux_socket_unix_stream_connect(struct socket *sock, 3932 struct socket *other, 3933 struct sock *newsk) 3934{ 3935 struct sk_security_struct *sksec_sock = sock->sk->sk_security; 3936 struct sk_security_struct *sksec_other = other->sk->sk_security; 3937 struct sk_security_struct *sksec_new = newsk->sk_security; 3938 struct common_audit_data ad; 3939 int err; 3940 3941 COMMON_AUDIT_DATA_INIT(&ad, NET); 3942 ad.u.net.sk = other->sk; 3943 3944 err = avc_has_perm(sksec_sock->sid, sksec_other->sid, 3945 sksec_other->sclass, 3946 UNIX_STREAM_SOCKET__CONNECTTO, &ad); 3947 if (err) 3948 return err; 3949 3950 /* server child socket */ 3951 sksec_new->peer_sid = sksec_sock->sid; 3952 err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid, 3953 &sksec_new->sid); 3954 if (err) 3955 return err; 3956 3957 /* connecting socket */ 3958 sksec_sock->peer_sid = sksec_new->sid; 3959 3960 return 0; 3961} 3962 3963static int selinux_socket_unix_may_send(struct socket *sock, 3964 struct socket *other) 3965{ 3966 struct sk_security_struct *ssec = sock->sk->sk_security; 3967 struct sk_security_struct *osec = other->sk->sk_security; 3968 struct common_audit_data ad; 3969 3970 COMMON_AUDIT_DATA_INIT(&ad, NET); 3971 ad.u.net.sk = other->sk; 3972 3973 return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO, 3974 &ad); 3975} 3976 3977static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family, 3978 u32 peer_sid, 3979 struct common_audit_data *ad) 3980{ 3981 int err; 3982 u32 if_sid; 3983 u32 node_sid; 3984 3985 err = sel_netif_sid(ifindex, &if_sid); 3986 if (err) 3987 return err; 3988 err = avc_has_perm(peer_sid, if_sid, 3989 SECCLASS_NETIF, NETIF__INGRESS, ad); 3990 if (err) 3991 return err; 3992 3993 err = sel_netnode_sid(addrp, family, &node_sid); 3994 if (err) 3995 return err; 3996 return avc_has_perm(peer_sid, node_sid, 3997 SECCLASS_NODE, NODE__RECVFROM, ad); 3998} 3999 4000static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, 4001 u16 family) 4002{ 4003 int err = 0; 4004 struct sk_security_struct *sksec = sk->sk_security; 4005 u32 peer_sid; 4006 u32 sk_sid = sksec->sid; 4007 struct common_audit_data ad; 4008 char *addrp; 4009 4010 COMMON_AUDIT_DATA_INIT(&ad, NET); 4011 ad.u.net.netif = skb->skb_iif; 4012 ad.u.net.family = family; 4013 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); 4014 if (err) 4015 return err; 4016 4017 if (selinux_secmark_enabled()) { 4018 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, 4019 PACKET__RECV, &ad); 4020 if (err) 4021 return err; 4022 } 4023 4024 if (selinux_policycap_netpeer) { 4025 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid); 4026 if (err) 4027 return err; 4028 err = avc_has_perm(sk_sid, peer_sid, 4029 SECCLASS_PEER, PEER__RECV, &ad); 4030 if (err) 4031 selinux_netlbl_err(skb, err, 0); 4032 } else { 4033 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad); 4034 if (err) 4035 return err; 4036 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad); 4037 } 4038 4039 return err; 4040} 4041 4042static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 4043{ 4044 int err; 4045 struct sk_security_struct *sksec = sk->sk_security; 4046 u16 family = sk->sk_family; 4047 u32 sk_sid = sksec->sid; 4048 struct common_audit_data ad; 4049 char *addrp; 4050 u8 secmark_active; 4051 u8 peerlbl_active; 4052 4053 if (family != PF_INET && family != PF_INET6) 4054 return 0; 4055 4056 /* Handle mapped IPv4 packets arriving via IPv6 sockets */ 4057 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4058 family = PF_INET; 4059 4060 /* If any sort of compatibility mode is enabled then handoff processing 4061 * to the selinux_sock_rcv_skb_compat() function to deal with the 4062 * special handling. We do this in an attempt to keep this function 4063 * as fast and as clean as possible. */ 4064 if (!selinux_policycap_netpeer) 4065 return selinux_sock_rcv_skb_compat(sk, skb, family); 4066 4067 secmark_active = selinux_secmark_enabled(); 4068 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled(); 4069 if (!secmark_active && !peerlbl_active) 4070 return 0; 4071 4072 COMMON_AUDIT_DATA_INIT(&ad, NET); 4073 ad.u.net.netif = skb->skb_iif; 4074 ad.u.net.family = family; 4075 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); 4076 if (err) 4077 return err; 4078 4079 if (peerlbl_active) { 4080 u32 peer_sid; 4081 4082 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid); 4083 if (err) 4084 return err; 4085 err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family, 4086 peer_sid, &ad); 4087 if (err) { 4088 selinux_netlbl_err(skb, err, 0); 4089 return err; 4090 } 4091 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER, 4092 PEER__RECV, &ad); 4093 if (err) 4094 selinux_netlbl_err(skb, err, 0); 4095 } 4096 4097 if (secmark_active) { 4098 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, 4099 PACKET__RECV, &ad); 4100 if (err) 4101 return err; 4102 } 4103 4104 return err; 4105} 4106 4107static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval, 4108 int __user *optlen, unsigned len) 4109{ 4110 int err = 0; 4111 char *scontext; 4112 u32 scontext_len; 4113 struct sk_security_struct *sksec = sock->sk->sk_security; 4114 u32 peer_sid = SECSID_NULL; 4115 4116 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET || 4117 sksec->sclass == SECCLASS_TCP_SOCKET) 4118 peer_sid = sksec->peer_sid; 4119 if (peer_sid == SECSID_NULL) 4120 return -ENOPROTOOPT; 4121 4122 err = security_sid_to_context(peer_sid, &scontext, &scontext_len); 4123 if (err) 4124 return err; 4125 4126 if (scontext_len > len) { 4127 err = -ERANGE; 4128 goto out_len; 4129 } 4130 4131 if (copy_to_user(optval, scontext, scontext_len)) 4132 err = -EFAULT; 4133 4134out_len: 4135 if (put_user(scontext_len, optlen)) 4136 err = -EFAULT; 4137 kfree(scontext); 4138 return err; 4139} 4140 4141static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) 4142{ 4143 u32 peer_secid = SECSID_NULL; 4144 u16 family; 4145 4146 if (skb && skb->protocol == htons(ETH_P_IP)) 4147 family = PF_INET; 4148 else if (skb && skb->protocol == htons(ETH_P_IPV6)) 4149 family = PF_INET6; 4150 else if (sock) 4151 family = sock->sk->sk_family; 4152 else 4153 goto out; 4154 4155 if (sock && family == PF_UNIX) 4156 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid); 4157 else if (skb) 4158 selinux_skb_peerlbl_sid(skb, family, &peer_secid); 4159 4160out: 4161 *secid = peer_secid; 4162 if (peer_secid == SECSID_NULL) 4163 return -EINVAL; 4164 return 0; 4165} 4166 4167static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority) 4168{ 4169 struct sk_security_struct *sksec; 4170 4171 sksec = kzalloc(sizeof(*sksec), priority); 4172 if (!sksec) 4173 return -ENOMEM; 4174 4175 sksec->peer_sid = SECINITSID_UNLABELED; 4176 sksec->sid = SECINITSID_UNLABELED; 4177 selinux_netlbl_sk_security_reset(sksec); 4178 sk->sk_security = sksec; 4179 4180 return 0; 4181} 4182 4183static void selinux_sk_free_security(struct sock *sk) 4184{ 4185 struct sk_security_struct *sksec = sk->sk_security; 4186 4187 sk->sk_security = NULL; 4188 selinux_netlbl_sk_security_free(sksec); 4189 kfree(sksec); 4190} 4191 4192static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk) 4193{ 4194 struct sk_security_struct *sksec = sk->sk_security; 4195 struct sk_security_struct *newsksec = newsk->sk_security; 4196 4197 newsksec->sid = sksec->sid; 4198 newsksec->peer_sid = sksec->peer_sid; 4199 newsksec->sclass = sksec->sclass; 4200 4201 selinux_netlbl_sk_security_reset(newsksec); 4202} 4203 4204static void selinux_sk_getsecid(struct sock *sk, u32 *secid) 4205{ 4206 if (!sk) 4207 *secid = SECINITSID_ANY_SOCKET; 4208 else { 4209 struct sk_security_struct *sksec = sk->sk_security; 4210 4211 *secid = sksec->sid; 4212 } 4213} 4214 4215static void selinux_sock_graft(struct sock *sk, struct socket *parent) 4216{ 4217 struct inode_security_struct *isec = SOCK_INODE(parent)->i_security; 4218 struct sk_security_struct *sksec = sk->sk_security; 4219 4220 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 || 4221 sk->sk_family == PF_UNIX) 4222 isec->sid = sksec->sid; 4223 sksec->sclass = isec->sclass; 4224} 4225 4226static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, 4227 struct request_sock *req) 4228{ 4229 struct sk_security_struct *sksec = sk->sk_security; 4230 int err; 4231 u16 family = sk->sk_family; 4232 u32 newsid; 4233 u32 peersid; 4234 4235 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 4236 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4237 family = PF_INET; 4238 4239 err = selinux_skb_peerlbl_sid(skb, family, &peersid); 4240 if (err) 4241 return err; 4242 if (peersid == SECSID_NULL) { 4243 req->secid = sksec->sid; 4244 req->peer_secid = SECSID_NULL; 4245 } else { 4246 err = security_sid_mls_copy(sksec->sid, peersid, &newsid); 4247 if (err) 4248 return err; 4249 req->secid = newsid; 4250 req->peer_secid = peersid; 4251 } 4252 4253 return selinux_netlbl_inet_conn_request(req, family); 4254} 4255 4256static void selinux_inet_csk_clone(struct sock *newsk, 4257 const struct request_sock *req) 4258{ 4259 struct sk_security_struct *newsksec = newsk->sk_security; 4260 4261 newsksec->sid = req->secid; 4262 newsksec->peer_sid = req->peer_secid; 4263 /* NOTE: Ideally, we should also get the isec->sid for the 4264 new socket in sync, but we don't have the isec available yet. 4265 So we will wait until sock_graft to do it, by which 4266 time it will have been created and available. */ 4267 4268 /* We don't need to take any sort of lock here as we are the only 4269 * thread with access to newsksec */ 4270 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family); 4271} 4272 4273static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) 4274{ 4275 u16 family = sk->sk_family; 4276 struct sk_security_struct *sksec = sk->sk_security; 4277 4278 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 4279 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4280 family = PF_INET; 4281 4282 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid); 4283} 4284 4285static void selinux_req_classify_flow(const struct request_sock *req, 4286 struct flowi *fl) 4287{ 4288 fl->secid = req->secid; 4289} 4290 4291static int selinux_tun_dev_create(void) 4292{ 4293 u32 sid = current_sid(); 4294 4295 /* we aren't taking into account the "sockcreate" SID since the socket 4296 * that is being created here is not a socket in the traditional sense, 4297 * instead it is a private sock, accessible only to the kernel, and 4298 * representing a wide range of network traffic spanning multiple 4299 * connections unlike traditional sockets - check the TUN driver to 4300 * get a better understanding of why this socket is special */ 4301 4302 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE, 4303 NULL); 4304} 4305 4306static void selinux_tun_dev_post_create(struct sock *sk) 4307{ 4308 struct sk_security_struct *sksec = sk->sk_security; 4309 4310 /* we don't currently perform any NetLabel based labeling here and it 4311 * isn't clear that we would want to do so anyway; while we could apply 4312 * labeling without the support of the TUN user the resulting labeled 4313 * traffic from the other end of the connection would almost certainly 4314 * cause confusion to the TUN user that had no idea network labeling 4315 * protocols were being used */ 4316 4317 /* see the comments in selinux_tun_dev_create() about why we don't use 4318 * the sockcreate SID here */ 4319 4320 sksec->sid = current_sid(); 4321 sksec->sclass = SECCLASS_TUN_SOCKET; 4322} 4323 4324static int selinux_tun_dev_attach(struct sock *sk) 4325{ 4326 struct sk_security_struct *sksec = sk->sk_security; 4327 u32 sid = current_sid(); 4328 int err; 4329 4330 err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET, 4331 TUN_SOCKET__RELABELFROM, NULL); 4332 if (err) 4333 return err; 4334 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, 4335 TUN_SOCKET__RELABELTO, NULL); 4336 if (err) 4337 return err; 4338 4339 sksec->sid = sid; 4340 4341 return 0; 4342} 4343 4344static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb) 4345{ 4346 int err = 0; 4347 u32 perm; 4348 struct nlmsghdr *nlh; 4349 struct sk_security_struct *sksec = sk->sk_security; 4350 4351 if (skb->len < NLMSG_SPACE(0)) { 4352 err = -EINVAL; 4353 goto out; 4354 } 4355 nlh = nlmsg_hdr(skb); 4356 4357 err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm); 4358 if (err) { 4359 if (err == -EINVAL) { 4360 audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR, 4361 "SELinux: unrecognized netlink message" 4362 " type=%hu for sclass=%hu\n", 4363 nlh->nlmsg_type, sksec->sclass); 4364 if (!selinux_enforcing || security_get_allow_unknown()) 4365 err = 0; 4366 } 4367 4368 /* Ignore */ 4369 if (err == -ENOENT) 4370 err = 0; 4371 goto out; 4372 } 4373 4374 err = sock_has_perm(current, sk, perm); 4375out: 4376 return err; 4377} 4378 4379#ifdef CONFIG_NETFILTER 4380 4381static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, 4382 u16 family) 4383{ 4384 int err; 4385 char *addrp; 4386 u32 peer_sid; 4387 struct common_audit_data ad; 4388 u8 secmark_active; 4389 u8 netlbl_active; 4390 u8 peerlbl_active; 4391 4392 if (!selinux_policycap_netpeer) 4393 return NF_ACCEPT; 4394 4395 secmark_active = selinux_secmark_enabled(); 4396 netlbl_active = netlbl_enabled(); 4397 peerlbl_active = netlbl_active || selinux_xfrm_enabled(); 4398 if (!secmark_active && !peerlbl_active) 4399 return NF_ACCEPT; 4400 4401 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0) 4402 return NF_DROP; 4403 4404 COMMON_AUDIT_DATA_INIT(&ad, NET); 4405 ad.u.net.netif = ifindex; 4406 ad.u.net.family = family; 4407 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0) 4408 return NF_DROP; 4409 4410 if (peerlbl_active) { 4411 err = selinux_inet_sys_rcv_skb(ifindex, addrp, family, 4412 peer_sid, &ad); 4413 if (err) { 4414 selinux_netlbl_err(skb, err, 1); 4415 return NF_DROP; 4416 } 4417 } 4418 4419 if (secmark_active) 4420 if (avc_has_perm(peer_sid, skb->secmark, 4421 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad)) 4422 return NF_DROP; 4423 4424 if (netlbl_active) 4425 /* we do this in the FORWARD path and not the POST_ROUTING 4426 * path because we want to make sure we apply the necessary 4427 * labeling before IPsec is applied so we can leverage AH 4428 * protection */ 4429 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0) 4430 return NF_DROP; 4431 4432 return NF_ACCEPT; 4433} 4434 4435static unsigned int selinux_ipv4_forward(unsigned int hooknum, 4436 struct sk_buff *skb, 4437 const struct net_device *in, 4438 const struct net_device *out, 4439 int (*okfn)(struct sk_buff *)) 4440{ 4441 return selinux_ip_forward(skb, in->ifindex, PF_INET); 4442} 4443 4444#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 4445static unsigned int selinux_ipv6_forward(unsigned int hooknum, 4446 struct sk_buff *skb, 4447 const struct net_device *in, 4448 const struct net_device *out, 4449 int (*okfn)(struct sk_buff *)) 4450{ 4451 return selinux_ip_forward(skb, in->ifindex, PF_INET6); 4452} 4453#endif /* IPV6 */ 4454 4455static unsigned int selinux_ip_output(struct sk_buff *skb, 4456 u16 family) 4457{ 4458 u32 sid; 4459 4460 if (!netlbl_enabled()) 4461 return NF_ACCEPT; 4462 4463 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path 4464 * because we want to make sure we apply the necessary labeling 4465 * before IPsec is applied so we can leverage AH protection */ 4466 if (skb->sk) { 4467 struct sk_security_struct *sksec = skb->sk->sk_security; 4468 sid = sksec->sid; 4469 } else 4470 sid = SECINITSID_KERNEL; 4471 if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0) 4472 return NF_DROP; 4473 4474 return NF_ACCEPT; 4475} 4476 4477static unsigned int selinux_ipv4_output(unsigned int hooknum, 4478 struct sk_buff *skb, 4479 const struct net_device *in, 4480 const struct net_device *out, 4481 int (*okfn)(struct sk_buff *)) 4482{ 4483 return selinux_ip_output(skb, PF_INET); 4484} 4485 4486static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb, 4487 int ifindex, 4488 u16 family) 4489{ 4490 struct sock *sk = skb->sk; 4491 struct sk_security_struct *sksec; 4492 struct common_audit_data ad; 4493 char *addrp; 4494 u8 proto; 4495 4496 if (sk == NULL) 4497 return NF_ACCEPT; 4498 sksec = sk->sk_security; 4499 4500 COMMON_AUDIT_DATA_INIT(&ad, NET); 4501 ad.u.net.netif = ifindex; 4502 ad.u.net.family = family; 4503 if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto)) 4504 return NF_DROP; 4505 4506 if (selinux_secmark_enabled()) 4507 if (avc_has_perm(sksec->sid, skb->secmark, 4508 SECCLASS_PACKET, PACKET__SEND, &ad)) 4509 return NF_DROP; 4510 4511 if (selinux_policycap_netpeer) 4512 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto)) 4513 return NF_DROP; 4514 4515 return NF_ACCEPT; 4516} 4517 4518static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, 4519 u16 family) 4520{ 4521 u32 secmark_perm; 4522 u32 peer_sid; 4523 struct sock *sk; 4524 struct common_audit_data ad; 4525 char *addrp; 4526 u8 secmark_active; 4527 u8 peerlbl_active; 4528 4529 /* If any sort of compatibility mode is enabled then handoff processing 4530 * to the selinux_ip_postroute_compat() function to deal with the 4531 * special handling. We do this in an attempt to keep this function 4532 * as fast and as clean as possible. */ 4533 if (!selinux_policycap_netpeer) 4534 return selinux_ip_postroute_compat(skb, ifindex, family); 4535#ifdef CONFIG_XFRM 4536 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec 4537 * packet transformation so allow the packet to pass without any checks 4538 * since we'll have another chance to perform access control checks 4539 * when the packet is on it's final way out. 4540 * NOTE: there appear to be some IPv6 multicast cases where skb->dst 4541 * is NULL, in this case go ahead and apply access control. */ 4542 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL) 4543 return NF_ACCEPT; 4544#endif 4545 secmark_active = selinux_secmark_enabled(); 4546 peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled(); 4547 if (!secmark_active && !peerlbl_active) 4548 return NF_ACCEPT; 4549 4550 /* if the packet is being forwarded then get the peer label from the 4551 * packet itself; otherwise check to see if it is from a local 4552 * application or the kernel, if from an application get the peer label 4553 * from the sending socket, otherwise use the kernel's sid */ 4554 sk = skb->sk; 4555 if (sk == NULL) { 4556 switch (family) { 4557 case PF_INET: 4558 if (IPCB(skb)->flags & IPSKB_FORWARDED) 4559 secmark_perm = PACKET__FORWARD_OUT; 4560 else 4561 secmark_perm = PACKET__SEND; 4562 break; 4563 case PF_INET6: 4564 if (IP6CB(skb)->flags & IP6SKB_FORWARDED) 4565 secmark_perm = PACKET__FORWARD_OUT; 4566 else 4567 secmark_perm = PACKET__SEND; 4568 break; 4569 default: 4570 return NF_DROP; 4571 } 4572 if (secmark_perm == PACKET__FORWARD_OUT) { 4573 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid)) 4574 return NF_DROP; 4575 } else 4576 peer_sid = SECINITSID_KERNEL; 4577 } else { 4578 struct sk_security_struct *sksec = sk->sk_security; 4579 peer_sid = sksec->sid; 4580 secmark_perm = PACKET__SEND; 4581 } 4582 4583 COMMON_AUDIT_DATA_INIT(&ad, NET); 4584 ad.u.net.netif = ifindex; 4585 ad.u.net.family = family; 4586 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL)) 4587 return NF_DROP; 4588 4589 if (secmark_active) 4590 if (avc_has_perm(peer_sid, skb->secmark, 4591 SECCLASS_PACKET, secmark_perm, &ad)) 4592 return NF_DROP; 4593 4594 if (peerlbl_active) { 4595 u32 if_sid; 4596 u32 node_sid; 4597 4598 if (sel_netif_sid(ifindex, &if_sid)) 4599 return NF_DROP; 4600 if (avc_has_perm(peer_sid, if_sid, 4601 SECCLASS_NETIF, NETIF__EGRESS, &ad)) 4602 return NF_DROP; 4603 4604 if (sel_netnode_sid(addrp, family, &node_sid)) 4605 return NF_DROP; 4606 if (avc_has_perm(peer_sid, node_sid, 4607 SECCLASS_NODE, NODE__SENDTO, &ad)) 4608 return NF_DROP; 4609 } 4610 4611 return NF_ACCEPT; 4612} 4613 4614static unsigned int selinux_ipv4_postroute(unsigned int hooknum, 4615 struct sk_buff *skb, 4616 const struct net_device *in, 4617 const struct net_device *out, 4618 int (*okfn)(struct sk_buff *)) 4619{ 4620 return selinux_ip_postroute(skb, out->ifindex, PF_INET); 4621} 4622 4623#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 4624static unsigned int selinux_ipv6_postroute(unsigned int hooknum, 4625 struct sk_buff *skb, 4626 const struct net_device *in, 4627 const struct net_device *out, 4628 int (*okfn)(struct sk_buff *)) 4629{ 4630 return selinux_ip_postroute(skb, out->ifindex, PF_INET6); 4631} 4632#endif /* IPV6 */ 4633 4634#endif /* CONFIG_NETFILTER */ 4635 4636static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb) 4637{ 4638 int err; 4639 4640 err = cap_netlink_send(sk, skb); 4641 if (err) 4642 return err; 4643 4644 return selinux_nlmsg_perm(sk, skb); 4645} 4646 4647static int selinux_netlink_recv(struct sk_buff *skb, int capability) 4648{ 4649 int err; 4650 struct common_audit_data ad; 4651 4652 err = cap_netlink_recv(skb, capability); 4653 if (err) 4654 return err; 4655 4656 COMMON_AUDIT_DATA_INIT(&ad, CAP); 4657 ad.u.cap = capability; 4658 4659 return avc_has_perm(NETLINK_CB(skb).sid, NETLINK_CB(skb).sid, 4660 SECCLASS_CAPABILITY, CAP_TO_MASK(capability), &ad); 4661} 4662 4663static int ipc_alloc_security(struct task_struct *task, 4664 struct kern_ipc_perm *perm, 4665 u16 sclass) 4666{ 4667 struct ipc_security_struct *isec; 4668 u32 sid; 4669 4670 isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL); 4671 if (!isec) 4672 return -ENOMEM; 4673 4674 sid = task_sid(task); 4675 isec->sclass = sclass; 4676 isec->sid = sid; 4677 perm->security = isec; 4678 4679 return 0; 4680} 4681 4682static void ipc_free_security(struct kern_ipc_perm *perm) 4683{ 4684 struct ipc_security_struct *isec = perm->security; 4685 perm->security = NULL; 4686 kfree(isec); 4687} 4688 4689static int msg_msg_alloc_security(struct msg_msg *msg) 4690{ 4691 struct msg_security_struct *msec; 4692 4693 msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL); 4694 if (!msec) 4695 return -ENOMEM; 4696 4697 msec->sid = SECINITSID_UNLABELED; 4698 msg->security = msec; 4699 4700 return 0; 4701} 4702 4703static void msg_msg_free_security(struct msg_msg *msg) 4704{ 4705 struct msg_security_struct *msec = msg->security; 4706 4707 msg->security = NULL; 4708 kfree(msec); 4709} 4710 4711static int ipc_has_perm(struct kern_ipc_perm *ipc_perms, 4712 u32 perms) 4713{ 4714 struct ipc_security_struct *isec; 4715 struct common_audit_data ad; 4716 u32 sid = current_sid(); 4717 4718 isec = ipc_perms->security; 4719 4720 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4721 ad.u.ipc_id = ipc_perms->key; 4722 4723 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad); 4724} 4725 4726static int selinux_msg_msg_alloc_security(struct msg_msg *msg) 4727{ 4728 return msg_msg_alloc_security(msg); 4729} 4730 4731static void selinux_msg_msg_free_security(struct msg_msg *msg) 4732{ 4733 msg_msg_free_security(msg); 4734} 4735 4736/* message queue security operations */ 4737static int selinux_msg_queue_alloc_security(struct msg_queue *msq) 4738{ 4739 struct ipc_security_struct *isec; 4740 struct common_audit_data ad; 4741 u32 sid = current_sid(); 4742 int rc; 4743 4744 rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ); 4745 if (rc) 4746 return rc; 4747 4748 isec = msq->q_perm.security; 4749 4750 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4751 ad.u.ipc_id = msq->q_perm.key; 4752 4753 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 4754 MSGQ__CREATE, &ad); 4755 if (rc) { 4756 ipc_free_security(&msq->q_perm); 4757 return rc; 4758 } 4759 return 0; 4760} 4761 4762static void selinux_msg_queue_free_security(struct msg_queue *msq) 4763{ 4764 ipc_free_security(&msq->q_perm); 4765} 4766 4767static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg) 4768{ 4769 struct ipc_security_struct *isec; 4770 struct common_audit_data ad; 4771 u32 sid = current_sid(); 4772 4773 isec = msq->q_perm.security; 4774 4775 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4776 ad.u.ipc_id = msq->q_perm.key; 4777 4778 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 4779 MSGQ__ASSOCIATE, &ad); 4780} 4781 4782static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd) 4783{ 4784 int err; 4785 int perms; 4786 4787 switch (cmd) { 4788 case IPC_INFO: 4789 case MSG_INFO: 4790 /* No specific object, just general system-wide information. */ 4791 return task_has_system(current, SYSTEM__IPC_INFO); 4792 case IPC_STAT: 4793 case MSG_STAT: 4794 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE; 4795 break; 4796 case IPC_SET: 4797 perms = MSGQ__SETATTR; 4798 break; 4799 case IPC_RMID: 4800 perms = MSGQ__DESTROY; 4801 break; 4802 default: 4803 return 0; 4804 } 4805 4806 err = ipc_has_perm(&msq->q_perm, perms); 4807 return err; 4808} 4809 4810static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg) 4811{ 4812 struct ipc_security_struct *isec; 4813 struct msg_security_struct *msec; 4814 struct common_audit_data ad; 4815 u32 sid = current_sid(); 4816 int rc; 4817 4818 isec = msq->q_perm.security; 4819 msec = msg->security; 4820 4821 /* 4822 * First time through, need to assign label to the message 4823 */ 4824 if (msec->sid == SECINITSID_UNLABELED) { 4825 /* 4826 * Compute new sid based on current process and 4827 * message queue this message will be stored in 4828 */ 4829 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG, 4830 &msec->sid); 4831 if (rc) 4832 return rc; 4833 } 4834 4835 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4836 ad.u.ipc_id = msq->q_perm.key; 4837 4838 /* Can this process write to the queue? */ 4839 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 4840 MSGQ__WRITE, &ad); 4841 if (!rc) 4842 /* Can this process send the message */ 4843 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG, 4844 MSG__SEND, &ad); 4845 if (!rc) 4846 /* Can the message be put in the queue? */ 4847 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ, 4848 MSGQ__ENQUEUE, &ad); 4849 4850 return rc; 4851} 4852 4853static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, 4854 struct task_struct *target, 4855 long type, int mode) 4856{ 4857 struct ipc_security_struct *isec; 4858 struct msg_security_struct *msec; 4859 struct common_audit_data ad; 4860 u32 sid = task_sid(target); 4861 int rc; 4862 4863 isec = msq->q_perm.security; 4864 msec = msg->security; 4865 4866 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4867 ad.u.ipc_id = msq->q_perm.key; 4868 4869 rc = avc_has_perm(sid, isec->sid, 4870 SECCLASS_MSGQ, MSGQ__READ, &ad); 4871 if (!rc) 4872 rc = avc_has_perm(sid, msec->sid, 4873 SECCLASS_MSG, MSG__RECEIVE, &ad); 4874 return rc; 4875} 4876 4877/* Shared Memory security operations */ 4878static int selinux_shm_alloc_security(struct shmid_kernel *shp) 4879{ 4880 struct ipc_security_struct *isec; 4881 struct common_audit_data ad; 4882 u32 sid = current_sid(); 4883 int rc; 4884 4885 rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM); 4886 if (rc) 4887 return rc; 4888 4889 isec = shp->shm_perm.security; 4890 4891 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4892 ad.u.ipc_id = shp->shm_perm.key; 4893 4894 rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM, 4895 SHM__CREATE, &ad); 4896 if (rc) { 4897 ipc_free_security(&shp->shm_perm); 4898 return rc; 4899 } 4900 return 0; 4901} 4902 4903static void selinux_shm_free_security(struct shmid_kernel *shp) 4904{ 4905 ipc_free_security(&shp->shm_perm); 4906} 4907 4908static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg) 4909{ 4910 struct ipc_security_struct *isec; 4911 struct common_audit_data ad; 4912 u32 sid = current_sid(); 4913 4914 isec = shp->shm_perm.security; 4915 4916 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4917 ad.u.ipc_id = shp->shm_perm.key; 4918 4919 return avc_has_perm(sid, isec->sid, SECCLASS_SHM, 4920 SHM__ASSOCIATE, &ad); 4921} 4922 4923/* Note, at this point, shp is locked down */ 4924static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd) 4925{ 4926 int perms; 4927 int err; 4928 4929 switch (cmd) { 4930 case IPC_INFO: 4931 case SHM_INFO: 4932 /* No specific object, just general system-wide information. */ 4933 return task_has_system(current, SYSTEM__IPC_INFO); 4934 case IPC_STAT: 4935 case SHM_STAT: 4936 perms = SHM__GETATTR | SHM__ASSOCIATE; 4937 break; 4938 case IPC_SET: 4939 perms = SHM__SETATTR; 4940 break; 4941 case SHM_LOCK: 4942 case SHM_UNLOCK: 4943 perms = SHM__LOCK; 4944 break; 4945 case IPC_RMID: 4946 perms = SHM__DESTROY; 4947 break; 4948 default: 4949 return 0; 4950 } 4951 4952 err = ipc_has_perm(&shp->shm_perm, perms); 4953 return err; 4954} 4955 4956static int selinux_shm_shmat(struct shmid_kernel *shp, 4957 char __user *shmaddr, int shmflg) 4958{ 4959 u32 perms; 4960 4961 if (shmflg & SHM_RDONLY) 4962 perms = SHM__READ; 4963 else 4964 perms = SHM__READ | SHM__WRITE; 4965 4966 return ipc_has_perm(&shp->shm_perm, perms); 4967} 4968 4969/* Semaphore security operations */ 4970static int selinux_sem_alloc_security(struct sem_array *sma) 4971{ 4972 struct ipc_security_struct *isec; 4973 struct common_audit_data ad; 4974 u32 sid = current_sid(); 4975 int rc; 4976 4977 rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM); 4978 if (rc) 4979 return rc; 4980 4981 isec = sma->sem_perm.security; 4982 4983 COMMON_AUDIT_DATA_INIT(&ad, IPC); 4984 ad.u.ipc_id = sma->sem_perm.key; 4985 4986 rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM, 4987 SEM__CREATE, &ad); 4988 if (rc) { 4989 ipc_free_security(&sma->sem_perm); 4990 return rc; 4991 } 4992 return 0; 4993} 4994 4995static void selinux_sem_free_security(struct sem_array *sma) 4996{ 4997 ipc_free_security(&sma->sem_perm); 4998} 4999 5000static int selinux_sem_associate(struct sem_array *sma, int semflg) 5001{ 5002 struct ipc_security_struct *isec; 5003 struct common_audit_data ad; 5004 u32 sid = current_sid(); 5005 5006 isec = sma->sem_perm.security; 5007 5008 COMMON_AUDIT_DATA_INIT(&ad, IPC); 5009 ad.u.ipc_id = sma->sem_perm.key; 5010 5011 return avc_has_perm(sid, isec->sid, SECCLASS_SEM, 5012 SEM__ASSOCIATE, &ad); 5013} 5014 5015/* Note, at this point, sma is locked down */ 5016static int selinux_sem_semctl(struct sem_array *sma, int cmd) 5017{ 5018 int err; 5019 u32 perms; 5020 5021 switch (cmd) { 5022 case IPC_INFO: 5023 case SEM_INFO: 5024 /* No specific object, just general system-wide information. */ 5025 return task_has_system(current, SYSTEM__IPC_INFO); 5026 case GETPID: 5027 case GETNCNT: 5028 case GETZCNT: 5029 perms = SEM__GETATTR; 5030 break; 5031 case GETVAL: 5032 case GETALL: 5033 perms = SEM__READ; 5034 break; 5035 case SETVAL: 5036 case SETALL: 5037 perms = SEM__WRITE; 5038 break; 5039 case IPC_RMID: 5040 perms = SEM__DESTROY; 5041 break; 5042 case IPC_SET: 5043 perms = SEM__SETATTR; 5044 break; 5045 case IPC_STAT: 5046 case SEM_STAT: 5047 perms = SEM__GETATTR | SEM__ASSOCIATE; 5048 break; 5049 default: 5050 return 0; 5051 } 5052 5053 err = ipc_has_perm(&sma->sem_perm, perms); 5054 return err; 5055} 5056 5057static int selinux_sem_semop(struct sem_array *sma, 5058 struct sembuf *sops, unsigned nsops, int alter) 5059{ 5060 u32 perms; 5061 5062 if (alter) 5063 perms = SEM__READ | SEM__WRITE; 5064 else 5065 perms = SEM__READ; 5066 5067 return ipc_has_perm(&sma->sem_perm, perms); 5068} 5069 5070static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag) 5071{ 5072 u32 av = 0; 5073 5074 av = 0; 5075 if (flag & S_IRUGO) 5076 av |= IPC__UNIX_READ; 5077 if (flag & S_IWUGO) 5078 av |= IPC__UNIX_WRITE; 5079 5080 if (av == 0) 5081 return 0; 5082 5083 return ipc_has_perm(ipcp, av); 5084} 5085 5086static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid) 5087{ 5088 struct ipc_security_struct *isec = ipcp->security; 5089 *secid = isec->sid; 5090} 5091 5092static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode) 5093{ 5094 if (inode) 5095 inode_doinit_with_dentry(inode, dentry); 5096} 5097 5098static int selinux_getprocattr(struct task_struct *p, 5099 char *name, char **value) 5100{ 5101 const struct task_security_struct *__tsec; 5102 u32 sid; 5103 int error; 5104 unsigned len; 5105 5106 if (current != p) { 5107 error = current_has_perm(p, PROCESS__GETATTR); 5108 if (error) 5109 return error; 5110 } 5111 5112 rcu_read_lock(); 5113 __tsec = __task_cred(p)->security; 5114 5115 if (!strcmp(name, "current")) 5116 sid = __tsec->sid; 5117 else if (!strcmp(name, "prev")) 5118 sid = __tsec->osid; 5119 else if (!strcmp(name, "exec")) 5120 sid = __tsec->exec_sid; 5121 else if (!strcmp(name, "fscreate")) 5122 sid = __tsec->create_sid; 5123 else if (!strcmp(name, "keycreate")) 5124 sid = __tsec->keycreate_sid; 5125 else if (!strcmp(name, "sockcreate")) 5126 sid = __tsec->sockcreate_sid; 5127 else 5128 goto invalid; 5129 rcu_read_unlock(); 5130 5131 if (!sid) 5132 return 0; 5133 5134 error = security_sid_to_context(sid, value, &len); 5135 if (error) 5136 return error; 5137 return len; 5138 5139invalid: 5140 rcu_read_unlock(); 5141 return -EINVAL; 5142} 5143 5144static int selinux_setprocattr(struct task_struct *p, 5145 char *name, void *value, size_t size) 5146{ 5147 struct task_security_struct *tsec; 5148 struct task_struct *tracer; 5149 struct cred *new; 5150 u32 sid = 0, ptsid; 5151 int error; 5152 char *str = value; 5153 5154 if (current != p) { 5155 /* SELinux only allows a process to change its own 5156 security attributes. */ 5157 return -EACCES; 5158 } 5159 5160 /* 5161 * Basic control over ability to set these attributes at all. 5162 * current == p, but we'll pass them separately in case the 5163 * above restriction is ever removed. 5164 */ 5165 if (!strcmp(name, "exec")) 5166 error = current_has_perm(p, PROCESS__SETEXEC); 5167 else if (!strcmp(name, "fscreate")) 5168 error = current_has_perm(p, PROCESS__SETFSCREATE); 5169 else if (!strcmp(name, "keycreate")) 5170 error = current_has_perm(p, PROCESS__SETKEYCREATE); 5171 else if (!strcmp(name, "sockcreate")) 5172 error = current_has_perm(p, PROCESS__SETSOCKCREATE); 5173 else if (!strcmp(name, "current")) 5174 error = current_has_perm(p, PROCESS__SETCURRENT); 5175 else 5176 error = -EINVAL; 5177 if (error) 5178 return error; 5179 5180 /* Obtain a SID for the context, if one was specified. */ 5181 if (size && str[1] && str[1] != '\n') { 5182 if (str[size-1] == '\n') { 5183 str[size-1] = 0; 5184 size--; 5185 } 5186 error = security_context_to_sid(value, size, &sid); 5187 if (error == -EINVAL && !strcmp(name, "fscreate")) { 5188 if (!capable(CAP_MAC_ADMIN)) 5189 return error; 5190 error = security_context_to_sid_force(value, size, 5191 &sid); 5192 } 5193 if (error) 5194 return error; 5195 } 5196 5197 new = prepare_creds(); 5198 if (!new) 5199 return -ENOMEM; 5200 5201 /* Permission checking based on the specified context is 5202 performed during the actual operation (execve, 5203 open/mkdir/...), when we know the full context of the 5204 operation. See selinux_bprm_set_creds for the execve 5205 checks and may_create for the file creation checks. The 5206 operation will then fail if the context is not permitted. */ 5207 tsec = new->security; 5208 if (!strcmp(name, "exec")) { 5209 tsec->exec_sid = sid; 5210 } else if (!strcmp(name, "fscreate")) { 5211 tsec->create_sid = sid; 5212 } else if (!strcmp(name, "keycreate")) { 5213 error = may_create_key(sid, p); 5214 if (error) 5215 goto abort_change; 5216 tsec->keycreate_sid = sid; 5217 } else if (!strcmp(name, "sockcreate")) { 5218 tsec->sockcreate_sid = sid; 5219 } else if (!strcmp(name, "current")) { 5220 error = -EINVAL; 5221 if (sid == 0) 5222 goto abort_change; 5223 5224 /* Only allow single threaded processes to change context */ 5225 error = -EPERM; 5226 if (!current_is_single_threaded()) { 5227 error = security_bounded_transition(tsec->sid, sid); 5228 if (error) 5229 goto abort_change; 5230 } 5231 5232 /* Check permissions for the transition. */ 5233 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS, 5234 PROCESS__DYNTRANSITION, NULL); 5235 if (error) 5236 goto abort_change; 5237 5238 /* Check for ptracing, and update the task SID if ok. 5239 Otherwise, leave SID unchanged and fail. */ 5240 ptsid = 0; 5241 task_lock(p); 5242 tracer = tracehook_tracer_task(p); 5243 if (tracer) 5244 ptsid = task_sid(tracer); 5245 task_unlock(p); 5246 5247 if (tracer) { 5248 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS, 5249 PROCESS__PTRACE, NULL); 5250 if (error) 5251 goto abort_change; 5252 } 5253 5254 tsec->sid = sid; 5255 } else { 5256 error = -EINVAL; 5257 goto abort_change; 5258 } 5259 5260 commit_creds(new); 5261 return size; 5262 5263abort_change: 5264 abort_creds(new); 5265 return error; 5266} 5267 5268static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) 5269{ 5270 return security_sid_to_context(secid, secdata, seclen); 5271} 5272 5273static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) 5274{ 5275 return security_context_to_sid(secdata, seclen, secid); 5276} 5277 5278static void selinux_release_secctx(char *secdata, u32 seclen) 5279{ 5280 kfree(secdata); 5281} 5282 5283/* 5284 * called with inode->i_mutex locked 5285 */ 5286static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) 5287{ 5288 return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0); 5289} 5290 5291/* 5292 * called with inode->i_mutex locked 5293 */ 5294static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) 5295{ 5296 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0); 5297} 5298 5299static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) 5300{ 5301 int len = 0; 5302 len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX, 5303 ctx, true); 5304 if (len < 0) 5305 return len; 5306 *ctxlen = len; 5307 return 0; 5308} 5309#ifdef CONFIG_KEYS 5310 5311static int selinux_key_alloc(struct key *k, const struct cred *cred, 5312 unsigned long flags) 5313{ 5314 const struct task_security_struct *tsec; 5315 struct key_security_struct *ksec; 5316 5317 ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL); 5318 if (!ksec) 5319 return -ENOMEM; 5320 5321 tsec = cred->security; 5322 if (tsec->keycreate_sid) 5323 ksec->sid = tsec->keycreate_sid; 5324 else 5325 ksec->sid = tsec->sid; 5326 5327 k->security = ksec; 5328 return 0; 5329} 5330 5331static void selinux_key_free(struct key *k) 5332{ 5333 struct key_security_struct *ksec = k->security; 5334 5335 k->security = NULL; 5336 kfree(ksec); 5337} 5338 5339static int selinux_key_permission(key_ref_t key_ref, 5340 const struct cred *cred, 5341 key_perm_t perm) 5342{ 5343 struct key *key; 5344 struct key_security_struct *ksec; 5345 u32 sid; 5346 5347 /* if no specific permissions are requested, we skip the 5348 permission check. No serious, additional covert channels 5349 appear to be created. */ 5350 if (perm == 0) 5351 return 0; 5352 5353 sid = cred_sid(cred); 5354 5355 key = key_ref_to_ptr(key_ref); 5356 ksec = key->security; 5357 5358 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL); 5359} 5360 5361static int selinux_key_getsecurity(struct key *key, char **_buffer) 5362{ 5363 struct key_security_struct *ksec = key->security; 5364 char *context = NULL; 5365 unsigned len; 5366 int rc; 5367 5368 rc = security_sid_to_context(ksec->sid, &context, &len); 5369 if (!rc) 5370 rc = len; 5371 *_buffer = context; 5372 return rc; 5373} 5374 5375#endif 5376 5377static struct security_operations selinux_ops = { 5378 .name = "selinux", 5379 5380 .ptrace_access_check = selinux_ptrace_access_check, 5381 .ptrace_traceme = selinux_ptrace_traceme, 5382 .capget = selinux_capget, 5383 .capset = selinux_capset, 5384 .sysctl = selinux_sysctl, 5385 .capable = selinux_capable, 5386 .quotactl = selinux_quotactl, 5387 .quota_on = selinux_quota_on, 5388 .syslog = selinux_syslog, 5389 .vm_enough_memory = selinux_vm_enough_memory, 5390 5391 .netlink_send = selinux_netlink_send, 5392 .netlink_recv = selinux_netlink_recv, 5393 5394 .bprm_set_creds = selinux_bprm_set_creds, 5395 .bprm_committing_creds = selinux_bprm_committing_creds, 5396 .bprm_committed_creds = selinux_bprm_committed_creds, 5397 .bprm_secureexec = selinux_bprm_secureexec, 5398 5399 .sb_alloc_security = selinux_sb_alloc_security, 5400 .sb_free_security = selinux_sb_free_security, 5401 .sb_copy_data = selinux_sb_copy_data, 5402 .sb_kern_mount = selinux_sb_kern_mount, 5403 .sb_show_options = selinux_sb_show_options, 5404 .sb_statfs = selinux_sb_statfs, 5405 .sb_mount = selinux_mount, 5406 .sb_umount = selinux_umount, 5407 .sb_set_mnt_opts = selinux_set_mnt_opts, 5408 .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts, 5409 .sb_parse_opts_str = selinux_parse_opts_str, 5410 5411 5412 .inode_alloc_security = selinux_inode_alloc_security, 5413 .inode_free_security = selinux_inode_free_security, 5414 .inode_init_security = selinux_inode_init_security, 5415 .inode_create = selinux_inode_create, 5416 .inode_link = selinux_inode_link, 5417 .inode_unlink = selinux_inode_unlink, 5418 .inode_symlink = selinux_inode_symlink, 5419 .inode_mkdir = selinux_inode_mkdir, 5420 .inode_rmdir = selinux_inode_rmdir, 5421 .inode_mknod = selinux_inode_mknod, 5422 .inode_rename = selinux_inode_rename, 5423 .inode_readlink = selinux_inode_readlink, 5424 .inode_follow_link = selinux_inode_follow_link, 5425 .inode_permission = selinux_inode_permission, 5426 .inode_setattr = selinux_inode_setattr, 5427 .inode_getattr = selinux_inode_getattr, 5428 .inode_setxattr = selinux_inode_setxattr, 5429 .inode_post_setxattr = selinux_inode_post_setxattr, 5430 .inode_getxattr = selinux_inode_getxattr, 5431 .inode_listxattr = selinux_inode_listxattr, 5432 .inode_removexattr = selinux_inode_removexattr, 5433 .inode_getsecurity = selinux_inode_getsecurity, 5434 .inode_setsecurity = selinux_inode_setsecurity, 5435 .inode_listsecurity = selinux_inode_listsecurity, 5436 .inode_getsecid = selinux_inode_getsecid, 5437 5438 .file_permission = selinux_file_permission, 5439 .file_alloc_security = selinux_file_alloc_security, 5440 .file_free_security = selinux_file_free_security, 5441 .file_ioctl = selinux_file_ioctl, 5442 .file_mmap = selinux_file_mmap, 5443 .file_mprotect = selinux_file_mprotect, 5444 .file_lock = selinux_file_lock, 5445 .file_fcntl = selinux_file_fcntl, 5446 .file_set_fowner = selinux_file_set_fowner, 5447 .file_send_sigiotask = selinux_file_send_sigiotask, 5448 .file_receive = selinux_file_receive, 5449 5450 .dentry_open = selinux_dentry_open, 5451 5452 .task_create = selinux_task_create, 5453 .cred_alloc_blank = selinux_cred_alloc_blank, 5454 .cred_free = selinux_cred_free, 5455 .cred_prepare = selinux_cred_prepare, 5456 .cred_transfer = selinux_cred_transfer, 5457 .kernel_act_as = selinux_kernel_act_as, 5458 .kernel_create_files_as = selinux_kernel_create_files_as, 5459 .kernel_module_request = selinux_kernel_module_request, 5460 .task_setpgid = selinux_task_setpgid, 5461 .task_getpgid = selinux_task_getpgid, 5462 .task_getsid = selinux_task_getsid, 5463 .task_getsecid = selinux_task_getsecid, 5464 .task_setnice = selinux_task_setnice, 5465 .task_setioprio = selinux_task_setioprio, 5466 .task_getioprio = selinux_task_getioprio, 5467 .task_setrlimit = selinux_task_setrlimit, 5468 .task_setscheduler = selinux_task_setscheduler, 5469 .task_getscheduler = selinux_task_getscheduler, 5470 .task_movememory = selinux_task_movememory, 5471 .task_kill = selinux_task_kill, 5472 .task_wait = selinux_task_wait, 5473 .task_to_inode = selinux_task_to_inode, 5474 5475 .ipc_permission = selinux_ipc_permission, 5476 .ipc_getsecid = selinux_ipc_getsecid, 5477 5478 .msg_msg_alloc_security = selinux_msg_msg_alloc_security, 5479 .msg_msg_free_security = selinux_msg_msg_free_security, 5480 5481 .msg_queue_alloc_security = selinux_msg_queue_alloc_security, 5482 .msg_queue_free_security = selinux_msg_queue_free_security, 5483 .msg_queue_associate = selinux_msg_queue_associate, 5484 .msg_queue_msgctl = selinux_msg_queue_msgctl, 5485 .msg_queue_msgsnd = selinux_msg_queue_msgsnd, 5486 .msg_queue_msgrcv = selinux_msg_queue_msgrcv, 5487 5488 .shm_alloc_security = selinux_shm_alloc_security, 5489 .shm_free_security = selinux_shm_free_security, 5490 .shm_associate = selinux_shm_associate, 5491 .shm_shmctl = selinux_shm_shmctl, 5492 .shm_shmat = selinux_shm_shmat, 5493 5494 .sem_alloc_security = selinux_sem_alloc_security, 5495 .sem_free_security = selinux_sem_free_security, 5496 .sem_associate = selinux_sem_associate, 5497 .sem_semctl = selinux_sem_semctl, 5498 .sem_semop = selinux_sem_semop, 5499 5500 .d_instantiate = selinux_d_instantiate, 5501 5502 .getprocattr = selinux_getprocattr, 5503 .setprocattr = selinux_setprocattr, 5504 5505 .secid_to_secctx = selinux_secid_to_secctx, 5506 .secctx_to_secid = selinux_secctx_to_secid, 5507 .release_secctx = selinux_release_secctx, 5508 .inode_notifysecctx = selinux_inode_notifysecctx, 5509 .inode_setsecctx = selinux_inode_setsecctx, 5510 .inode_getsecctx = selinux_inode_getsecctx, 5511 5512 .unix_stream_connect = selinux_socket_unix_stream_connect, 5513 .unix_may_send = selinux_socket_unix_may_send, 5514 5515 .socket_create = selinux_socket_create, 5516 .socket_post_create = selinux_socket_post_create, 5517 .socket_bind = selinux_socket_bind, 5518 .socket_connect = selinux_socket_connect, 5519 .socket_listen = selinux_socket_listen, 5520 .socket_accept = selinux_socket_accept, 5521 .socket_sendmsg = selinux_socket_sendmsg, 5522 .socket_recvmsg = selinux_socket_recvmsg, 5523 .socket_getsockname = selinux_socket_getsockname, 5524 .socket_getpeername = selinux_socket_getpeername, 5525 .socket_getsockopt = selinux_socket_getsockopt, 5526 .socket_setsockopt = selinux_socket_setsockopt, 5527 .socket_shutdown = selinux_socket_shutdown, 5528 .socket_sock_rcv_skb = selinux_socket_sock_rcv_skb, 5529 .socket_getpeersec_stream = selinux_socket_getpeersec_stream, 5530 .socket_getpeersec_dgram = selinux_socket_getpeersec_dgram, 5531 .sk_alloc_security = selinux_sk_alloc_security, 5532 .sk_free_security = selinux_sk_free_security, 5533 .sk_clone_security = selinux_sk_clone_security, 5534 .sk_getsecid = selinux_sk_getsecid, 5535 .sock_graft = selinux_sock_graft, 5536 .inet_conn_request = selinux_inet_conn_request, 5537 .inet_csk_clone = selinux_inet_csk_clone, 5538 .inet_conn_established = selinux_inet_conn_established, 5539 .req_classify_flow = selinux_req_classify_flow, 5540 .tun_dev_create = selinux_tun_dev_create, 5541 .tun_dev_post_create = selinux_tun_dev_post_create, 5542 .tun_dev_attach = selinux_tun_dev_attach, 5543 5544#ifdef CONFIG_SECURITY_NETWORK_XFRM 5545 .xfrm_policy_alloc_security = selinux_xfrm_policy_alloc, 5546 .xfrm_policy_clone_security = selinux_xfrm_policy_clone, 5547 .xfrm_policy_free_security = selinux_xfrm_policy_free, 5548 .xfrm_policy_delete_security = selinux_xfrm_policy_delete, 5549 .xfrm_state_alloc_security = selinux_xfrm_state_alloc, 5550 .xfrm_state_free_security = selinux_xfrm_state_free, 5551 .xfrm_state_delete_security = selinux_xfrm_state_delete, 5552 .xfrm_policy_lookup = selinux_xfrm_policy_lookup, 5553 .xfrm_state_pol_flow_match = selinux_xfrm_state_pol_flow_match, 5554 .xfrm_decode_session = selinux_xfrm_decode_session, 5555#endif 5556 5557#ifdef CONFIG_KEYS 5558 .key_alloc = selinux_key_alloc, 5559 .key_free = selinux_key_free, 5560 .key_permission = selinux_key_permission, 5561 .key_getsecurity = selinux_key_getsecurity, 5562#endif 5563 5564#ifdef CONFIG_AUDIT 5565 .audit_rule_init = selinux_audit_rule_init, 5566 .audit_rule_known = selinux_audit_rule_known, 5567 .audit_rule_match = selinux_audit_rule_match, 5568 .audit_rule_free = selinux_audit_rule_free, 5569#endif 5570}; 5571 5572static __init int selinux_init(void) 5573{ 5574 if (!security_module_enable(&selinux_ops)) { 5575 selinux_enabled = 0; 5576 return 0; 5577 } 5578 5579 if (!selinux_enabled) { 5580 printk(KERN_INFO "SELinux: Disabled at boot.\n"); 5581 return 0; 5582 } 5583 5584 printk(KERN_INFO "SELinux: Initializing.\n"); 5585 5586 /* Set the security state for the initial task. */ 5587 cred_init_security(); 5588 5589 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC); 5590 5591 sel_inode_cache = kmem_cache_create("selinux_inode_security", 5592 sizeof(struct inode_security_struct), 5593 0, SLAB_PANIC, NULL); 5594 avc_init(); 5595 5596 if (register_security(&selinux_ops)) 5597 panic("SELinux: Unable to register with kernel.\n"); 5598 5599 if (selinux_enforcing) 5600 printk(KERN_DEBUG "SELinux: Starting in enforcing mode\n"); 5601 else 5602 printk(KERN_DEBUG "SELinux: Starting in permissive mode\n"); 5603 5604 return 0; 5605} 5606 5607static void delayed_superblock_init(struct super_block *sb, void *unused) 5608{ 5609 superblock_doinit(sb, NULL); 5610} 5611 5612void selinux_complete_init(void) 5613{ 5614 printk(KERN_DEBUG "SELinux: Completing initialization.\n"); 5615 5616 /* Set up any superblocks initialized prior to the policy load. */ 5617 printk(KERN_DEBUG "SELinux: Setting up existing superblocks.\n"); 5618 iterate_supers(delayed_superblock_init, NULL); 5619} 5620 5621/* SELinux requires early initialization in order to label 5622 all processes and objects when they are created. */ 5623security_initcall(selinux_init); 5624 5625#if defined(CONFIG_NETFILTER) 5626 5627static struct nf_hook_ops selinux_ipv4_ops[] = { 5628 { 5629 .hook = selinux_ipv4_postroute, 5630 .owner = THIS_MODULE, 5631 .pf = PF_INET, 5632 .hooknum = NF_INET_POST_ROUTING, 5633 .priority = NF_IP_PRI_SELINUX_LAST, 5634 }, 5635 { 5636 .hook = selinux_ipv4_forward, 5637 .owner = THIS_MODULE, 5638 .pf = PF_INET, 5639 .hooknum = NF_INET_FORWARD, 5640 .priority = NF_IP_PRI_SELINUX_FIRST, 5641 }, 5642 { 5643 .hook = selinux_ipv4_output, 5644 .owner = THIS_MODULE, 5645 .pf = PF_INET, 5646 .hooknum = NF_INET_LOCAL_OUT, 5647 .priority = NF_IP_PRI_SELINUX_FIRST, 5648 } 5649}; 5650 5651#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 5652 5653static struct nf_hook_ops selinux_ipv6_ops[] = { 5654 { 5655 .hook = selinux_ipv6_postroute, 5656 .owner = THIS_MODULE, 5657 .pf = PF_INET6, 5658 .hooknum = NF_INET_POST_ROUTING, 5659 .priority = NF_IP6_PRI_SELINUX_LAST, 5660 }, 5661 { 5662 .hook = selinux_ipv6_forward, 5663 .owner = THIS_MODULE, 5664 .pf = PF_INET6, 5665 .hooknum = NF_INET_FORWARD, 5666 .priority = NF_IP6_PRI_SELINUX_FIRST, 5667 } 5668}; 5669 5670#endif /* IPV6 */ 5671 5672static int __init selinux_nf_ip_init(void) 5673{ 5674 int err = 0; 5675 5676 if (!selinux_enabled) 5677 goto out; 5678 5679 printk(KERN_DEBUG "SELinux: Registering netfilter hooks\n"); 5680 5681 err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops)); 5682 if (err) 5683 panic("SELinux: nf_register_hooks for IPv4: error %d\n", err); 5684 5685#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 5686 err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops)); 5687 if (err) 5688 panic("SELinux: nf_register_hooks for IPv6: error %d\n", err); 5689#endif /* IPV6 */ 5690 5691out: 5692 return err; 5693} 5694 5695__initcall(selinux_nf_ip_init); 5696 5697#ifdef CONFIG_SECURITY_SELINUX_DISABLE 5698static void selinux_nf_ip_exit(void) 5699{ 5700 printk(KERN_DEBUG "SELinux: Unregistering netfilter hooks\n"); 5701 5702 nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops)); 5703#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 5704 nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops)); 5705#endif /* IPV6 */ 5706} 5707#endif 5708 5709#else /* CONFIG_NETFILTER */ 5710 5711#ifdef CONFIG_SECURITY_SELINUX_DISABLE 5712#define selinux_nf_ip_exit() 5713#endif 5714 5715#endif /* CONFIG_NETFILTER */ 5716 5717#ifdef CONFIG_SECURITY_SELINUX_DISABLE 5718static int selinux_disabled; 5719 5720int selinux_disable(void) 5721{ 5722 extern void exit_sel_fs(void); 5723 5724 if (ss_initialized) { 5725 /* Not permitted after initial policy load. */ 5726 return -EINVAL; 5727 } 5728 5729 if (selinux_disabled) { 5730 /* Only do this once. */ 5731 return -EINVAL; 5732 } 5733 5734 printk(KERN_INFO "SELinux: Disabled at runtime.\n"); 5735 5736 selinux_disabled = 1; 5737 selinux_enabled = 0; 5738 5739 reset_security_ops(); 5740 5741 /* Try to destroy the avc node cache */ 5742 avc_disable(); 5743 5744 /* Unregister netfilter hooks. */ 5745 selinux_nf_ip_exit(); 5746 5747 /* Unregister selinuxfs. */ 5748 exit_sel_fs(); 5749 5750 return 0; 5751} 5752#endif 5753