1 /* 2 * NSA Security-Enhanced Linux (SELinux) security module 3 * 4 * This file contains the SELinux hook function implementations. 5 * 6 * Authors: Stephen Smalley, <sds@epoch.ncsc.mil> 7 * Chris Vance, <cvance@nai.com> 8 * Wayne Salamon, <wsalamon@nai.com> 9 * James Morris <jmorris@redhat.com> 10 * 11 * Copyright (C) 2001,2002 Networks Associates Technology, Inc. 12 * Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com> 13 * Eric Paris <eparis@redhat.com> 14 * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc. 15 * <dgoeddel@trustedcs.com> 16 * Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P. 17 * Paul Moore <paul@paul-moore.com> 18 * Copyright (C) 2007 Hitachi Software Engineering Co., Ltd. 19 * Yuichi Nakamura <ynakam@hitachisoft.jp> 20 * 21 * This program is free software; you can redistribute it and/or modify 22 * it under the terms of the GNU General Public License version 2, 23 * as published by the Free Software Foundation. 24 */ 25 26 #include <linux/init.h> 27 #include <linux/kd.h> 28 #include <linux/kernel.h> 29 #include <linux/tracehook.h> 30 #include <linux/errno.h> 31 #include <linux/sched.h> 32 #include <linux/security.h> 33 #include <linux/xattr.h> 34 #include <linux/capability.h> 35 #include <linux/unistd.h> 36 #include <linux/mm.h> 37 #include <linux/mman.h> 38 #include <linux/slab.h> 39 #include <linux/pagemap.h> 40 #include <linux/proc_fs.h> 41 #include <linux/swap.h> 42 #include <linux/spinlock.h> 43 #include <linux/syscalls.h> 44 #include <linux/dcache.h> 45 #include <linux/file.h> 46 #include <linux/fdtable.h> 47 #include <linux/namei.h> 48 #include <linux/mount.h> 49 #include <linux/netfilter_ipv4.h> 50 #include <linux/netfilter_ipv6.h> 51 #include <linux/tty.h> 52 #include <net/icmp.h> 53 #include <net/ip.h> /* for local_port_range[] */ 54 #include <net/sock.h> 55 #include <net/tcp.h> /* struct or_callable used in sock_rcv_skb */ 56 #include <net/inet_connection_sock.h> 57 #include <net/net_namespace.h> 58 #include <net/netlabel.h> 59 #include <linux/uaccess.h> 60 #include <asm/ioctls.h> 61 #include <linux/atomic.h> 62 #include <linux/bitops.h> 63 #include <linux/interrupt.h> 64 #include <linux/netdevice.h> /* for network interface checks */ 65 #include <net/netlink.h> 66 #include <linux/tcp.h> 67 #include <linux/udp.h> 68 #include <linux/dccp.h> 69 #include <linux/quota.h> 70 #include <linux/un.h> /* for Unix socket types */ 71 #include <net/af_unix.h> /* for Unix socket types */ 72 #include <linux/parser.h> 73 #include <linux/nfs_mount.h> 74 #include <net/ipv6.h> 75 #include <linux/hugetlb.h> 76 #include <linux/personality.h> 77 #include <linux/audit.h> 78 #include <linux/string.h> 79 #include <linux/selinux.h> 80 #include <linux/mutex.h> 81 #include <linux/posix-timers.h> 82 #include <linux/syslog.h> 83 #include <linux/user_namespace.h> 84 #include <linux/export.h> 85 #include <linux/msg.h> 86 #include <linux/shm.h> 87 88 #include "avc.h" 89 #include "objsec.h" 90 #include "netif.h" 91 #include "netnode.h" 92 #include "netport.h" 93 #include "xfrm.h" 94 #include "netlabel.h" 95 #include "audit.h" 96 #include "avc_ss.h" 97 98 extern struct security_operations *security_ops; 99 100 /* SECMARK reference count */ 101 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0); 102 103 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP 104 int selinux_enforcing; 105 106 static int __init enforcing_setup(char *str) 107 { 108 unsigned long enforcing; 109 if (!kstrtoul(str, 0, &enforcing)) 110 selinux_enforcing = enforcing ? 1 : 0; 111 return 1; 112 } 113 __setup("enforcing=", enforcing_setup); 114 #endif 115 116 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM 117 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE; 118 119 static int __init selinux_enabled_setup(char *str) 120 { 121 unsigned long enabled; 122 if (!kstrtoul(str, 0, &enabled)) 123 selinux_enabled = enabled ? 1 : 0; 124 return 1; 125 } 126 __setup("selinux=", selinux_enabled_setup); 127 #else 128 int selinux_enabled = 1; 129 #endif 130 131 static struct kmem_cache *sel_inode_cache; 132 133 /** 134 * selinux_secmark_enabled - Check to see if SECMARK is currently enabled 135 * 136 * Description: 137 * This function checks the SECMARK reference counter to see if any SECMARK 138 * targets are currently configured, if the reference counter is greater than 139 * zero SECMARK is considered to be enabled. Returns true (1) if SECMARK is 140 * enabled, false (0) if SECMARK is disabled. If the always_check_network 141 * policy capability is enabled, SECMARK is always considered enabled. 142 * 143 */ 144 static int selinux_secmark_enabled(void) 145 { 146 return (selinux_policycap_alwaysnetwork || atomic_read(&selinux_secmark_refcount)); 147 } 148 149 /** 150 * selinux_peerlbl_enabled - Check to see if peer labeling is currently enabled 151 * 152 * Description: 153 * This function checks if NetLabel or labeled IPSEC is enabled. Returns true 154 * (1) if any are enabled or false (0) if neither are enabled. If the 155 * always_check_network policy capability is enabled, peer labeling 156 * is always considered enabled. 157 * 158 */ 159 static int selinux_peerlbl_enabled(void) 160 { 161 return (selinux_policycap_alwaysnetwork || netlbl_enabled() || selinux_xfrm_enabled()); 162 } 163 164 /* 165 * initialise the security for the init task 166 */ 167 static void cred_init_security(void) 168 { 169 struct cred *cred = (struct cred *) current->real_cred; 170 struct task_security_struct *tsec; 171 172 tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL); 173 if (!tsec) 174 panic("SELinux: Failed to initialize initial task.\n"); 175 176 tsec->osid = tsec->sid = SECINITSID_KERNEL; 177 cred->security = tsec; 178 } 179 180 /* 181 * get the security ID of a set of credentials 182 */ 183 static inline u32 cred_sid(const struct cred *cred) 184 { 185 const struct task_security_struct *tsec; 186 187 tsec = cred->security; 188 return tsec->sid; 189 } 190 191 /* 192 * get the objective security ID of a task 193 */ 194 static inline u32 task_sid(const struct task_struct *task) 195 { 196 u32 sid; 197 198 rcu_read_lock(); 199 sid = cred_sid(__task_cred(task)); 200 rcu_read_unlock(); 201 return sid; 202 } 203 204 /* 205 * get the subjective security ID of the current task 206 */ 207 static inline u32 current_sid(void) 208 { 209 const struct task_security_struct *tsec = current_security(); 210 211 return tsec->sid; 212 } 213 214 /* Allocate and free functions for each kind of security blob. */ 215 216 static int inode_alloc_security(struct inode *inode) 217 { 218 struct inode_security_struct *isec; 219 u32 sid = current_sid(); 220 221 isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS); 222 if (!isec) 223 return -ENOMEM; 224 225 mutex_init(&isec->lock); 226 INIT_LIST_HEAD(&isec->list); 227 isec->inode = inode; 228 isec->sid = SECINITSID_UNLABELED; 229 isec->sclass = SECCLASS_FILE; 230 isec->task_sid = sid; 231 inode->i_security = isec; 232 233 return 0; 234 } 235 236 static void inode_free_rcu(struct rcu_head *head) 237 { 238 struct inode_security_struct *isec; 239 240 isec = container_of(head, struct inode_security_struct, rcu); 241 kmem_cache_free(sel_inode_cache, isec); 242 } 243 244 static void inode_free_security(struct inode *inode) 245 { 246 struct inode_security_struct *isec = inode->i_security; 247 struct superblock_security_struct *sbsec = inode->i_sb->s_security; 248 249 spin_lock(&sbsec->isec_lock); 250 if (!list_empty(&isec->list)) 251 list_del_init(&isec->list); 252 spin_unlock(&sbsec->isec_lock); 253 254 /* 255 * The inode may still be referenced in a path walk and 256 * a call to selinux_inode_permission() can be made 257 * after inode_free_security() is called. Ideally, the VFS 258 * wouldn't do this, but fixing that is a much harder 259 * job. For now, simply free the i_security via RCU, and 260 * leave the current inode->i_security pointer intact. 261 * The inode will be freed after the RCU grace period too. 262 */ 263 call_rcu(&isec->rcu, inode_free_rcu); 264 } 265 266 static int file_alloc_security(struct file *file) 267 { 268 struct file_security_struct *fsec; 269 u32 sid = current_sid(); 270 271 fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL); 272 if (!fsec) 273 return -ENOMEM; 274 275 fsec->sid = sid; 276 fsec->fown_sid = sid; 277 file->f_security = fsec; 278 279 return 0; 280 } 281 282 static void file_free_security(struct file *file) 283 { 284 struct file_security_struct *fsec = file->f_security; 285 file->f_security = NULL; 286 kfree(fsec); 287 } 288 289 static int superblock_alloc_security(struct super_block *sb) 290 { 291 struct superblock_security_struct *sbsec; 292 293 sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL); 294 if (!sbsec) 295 return -ENOMEM; 296 297 mutex_init(&sbsec->lock); 298 INIT_LIST_HEAD(&sbsec->isec_head); 299 spin_lock_init(&sbsec->isec_lock); 300 sbsec->sb = sb; 301 sbsec->sid = SECINITSID_UNLABELED; 302 sbsec->def_sid = SECINITSID_FILE; 303 sbsec->mntpoint_sid = SECINITSID_UNLABELED; 304 sb->s_security = sbsec; 305 306 return 0; 307 } 308 309 static void superblock_free_security(struct super_block *sb) 310 { 311 struct superblock_security_struct *sbsec = sb->s_security; 312 sb->s_security = NULL; 313 kfree(sbsec); 314 } 315 316 /* The file system's label must be initialized prior to use. */ 317 318 static const char *labeling_behaviors[7] = { 319 "uses xattr", 320 "uses transition SIDs", 321 "uses task SIDs", 322 "uses genfs_contexts", 323 "not configured for labeling", 324 "uses mountpoint labeling", 325 "uses native labeling", 326 }; 327 328 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry); 329 330 static inline int inode_doinit(struct inode *inode) 331 { 332 return inode_doinit_with_dentry(inode, NULL); 333 } 334 335 enum { 336 Opt_error = -1, 337 Opt_context = 1, 338 Opt_fscontext = 2, 339 Opt_defcontext = 3, 340 Opt_rootcontext = 4, 341 Opt_labelsupport = 5, 342 Opt_nextmntopt = 6, 343 }; 344 345 #define NUM_SEL_MNT_OPTS (Opt_nextmntopt - 1) 346 347 static const match_table_t tokens = { 348 {Opt_context, CONTEXT_STR "%s"}, 349 {Opt_fscontext, FSCONTEXT_STR "%s"}, 350 {Opt_defcontext, DEFCONTEXT_STR "%s"}, 351 {Opt_rootcontext, ROOTCONTEXT_STR "%s"}, 352 {Opt_labelsupport, LABELSUPP_STR}, 353 {Opt_error, NULL}, 354 }; 355 356 #define SEL_MOUNT_FAIL_MSG "SELinux: duplicate or incompatible mount options\n" 357 358 static int may_context_mount_sb_relabel(u32 sid, 359 struct superblock_security_struct *sbsec, 360 const struct cred *cred) 361 { 362 const struct task_security_struct *tsec = cred->security; 363 int rc; 364 365 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, 366 FILESYSTEM__RELABELFROM, NULL); 367 if (rc) 368 return rc; 369 370 rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM, 371 FILESYSTEM__RELABELTO, NULL); 372 return rc; 373 } 374 375 static int may_context_mount_inode_relabel(u32 sid, 376 struct superblock_security_struct *sbsec, 377 const struct cred *cred) 378 { 379 const struct task_security_struct *tsec = cred->security; 380 int rc; 381 rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM, 382 FILESYSTEM__RELABELFROM, NULL); 383 if (rc) 384 return rc; 385 386 rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, 387 FILESYSTEM__ASSOCIATE, NULL); 388 return rc; 389 } 390 391 static int selinux_is_sblabel_mnt(struct super_block *sb) 392 { 393 struct superblock_security_struct *sbsec = sb->s_security; 394 395 if (sbsec->behavior == SECURITY_FS_USE_XATTR || 396 sbsec->behavior == SECURITY_FS_USE_TRANS || 397 sbsec->behavior == SECURITY_FS_USE_TASK) 398 return 1; 399 400 /* Special handling for sysfs. Is genfs but also has setxattr handler*/ 401 if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0) 402 return 1; 403 404 /* 405 * Special handling for rootfs. Is genfs but supports 406 * setting SELinux context on in-core inodes. 407 */ 408 if (strncmp(sb->s_type->name, "rootfs", sizeof("rootfs")) == 0) 409 return 1; 410 411 return 0; 412 } 413 414 static int sb_finish_set_opts(struct super_block *sb) 415 { 416 struct superblock_security_struct *sbsec = sb->s_security; 417 struct dentry *root = sb->s_root; 418 struct inode *root_inode = root->d_inode; 419 int rc = 0; 420 421 if (sbsec->behavior == SECURITY_FS_USE_XATTR) { 422 /* Make sure that the xattr handler exists and that no 423 error other than -ENODATA is returned by getxattr on 424 the root directory. -ENODATA is ok, as this may be 425 the first boot of the SELinux kernel before we have 426 assigned xattr values to the filesystem. */ 427 if (!root_inode->i_op->getxattr) { 428 printk(KERN_WARNING "SELinux: (dev %s, type %s) has no " 429 "xattr support\n", sb->s_id, sb->s_type->name); 430 rc = -EOPNOTSUPP; 431 goto out; 432 } 433 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0); 434 if (rc < 0 && rc != -ENODATA) { 435 if (rc == -EOPNOTSUPP) 436 printk(KERN_WARNING "SELinux: (dev %s, type " 437 "%s) has no security xattr handler\n", 438 sb->s_id, sb->s_type->name); 439 else 440 printk(KERN_WARNING "SELinux: (dev %s, type " 441 "%s) getxattr errno %d\n", sb->s_id, 442 sb->s_type->name, -rc); 443 goto out; 444 } 445 } 446 447 if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors)) 448 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n", 449 sb->s_id, sb->s_type->name); 450 else 451 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n", 452 sb->s_id, sb->s_type->name, 453 labeling_behaviors[sbsec->behavior-1]); 454 455 sbsec->flags |= SE_SBINITIALIZED; 456 if (selinux_is_sblabel_mnt(sb)) 457 sbsec->flags |= SBLABEL_MNT; 458 459 /* Initialize the root inode. */ 460 rc = inode_doinit_with_dentry(root_inode, root); 461 462 /* Initialize any other inodes associated with the superblock, e.g. 463 inodes created prior to initial policy load or inodes created 464 during get_sb by a pseudo filesystem that directly 465 populates itself. */ 466 spin_lock(&sbsec->isec_lock); 467 next_inode: 468 if (!list_empty(&sbsec->isec_head)) { 469 struct inode_security_struct *isec = 470 list_entry(sbsec->isec_head.next, 471 struct inode_security_struct, list); 472 struct inode *inode = isec->inode; 473 spin_unlock(&sbsec->isec_lock); 474 inode = igrab(inode); 475 if (inode) { 476 if (!IS_PRIVATE(inode)) 477 inode_doinit(inode); 478 iput(inode); 479 } 480 spin_lock(&sbsec->isec_lock); 481 list_del_init(&isec->list); 482 goto next_inode; 483 } 484 spin_unlock(&sbsec->isec_lock); 485 out: 486 return rc; 487 } 488 489 /* 490 * This function should allow an FS to ask what it's mount security 491 * options were so it can use those later for submounts, displaying 492 * mount options, or whatever. 493 */ 494 static int selinux_get_mnt_opts(const struct super_block *sb, 495 struct security_mnt_opts *opts) 496 { 497 int rc = 0, i; 498 struct superblock_security_struct *sbsec = sb->s_security; 499 char *context = NULL; 500 u32 len; 501 char tmp; 502 503 security_init_mnt_opts(opts); 504 505 if (!(sbsec->flags & SE_SBINITIALIZED)) 506 return -EINVAL; 507 508 if (!ss_initialized) 509 return -EINVAL; 510 511 /* make sure we always check enough bits to cover the mask */ 512 BUILD_BUG_ON(SE_MNTMASK >= (1 << NUM_SEL_MNT_OPTS)); 513 514 tmp = sbsec->flags & SE_MNTMASK; 515 /* count the number of mount options for this sb */ 516 for (i = 0; i < NUM_SEL_MNT_OPTS; i++) { 517 if (tmp & 0x01) 518 opts->num_mnt_opts++; 519 tmp >>= 1; 520 } 521 /* Check if the Label support flag is set */ 522 if (sbsec->flags & SBLABEL_MNT) 523 opts->num_mnt_opts++; 524 525 opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC); 526 if (!opts->mnt_opts) { 527 rc = -ENOMEM; 528 goto out_free; 529 } 530 531 opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC); 532 if (!opts->mnt_opts_flags) { 533 rc = -ENOMEM; 534 goto out_free; 535 } 536 537 i = 0; 538 if (sbsec->flags & FSCONTEXT_MNT) { 539 rc = security_sid_to_context(sbsec->sid, &context, &len); 540 if (rc) 541 goto out_free; 542 opts->mnt_opts[i] = context; 543 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT; 544 } 545 if (sbsec->flags & CONTEXT_MNT) { 546 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len); 547 if (rc) 548 goto out_free; 549 opts->mnt_opts[i] = context; 550 opts->mnt_opts_flags[i++] = CONTEXT_MNT; 551 } 552 if (sbsec->flags & DEFCONTEXT_MNT) { 553 rc = security_sid_to_context(sbsec->def_sid, &context, &len); 554 if (rc) 555 goto out_free; 556 opts->mnt_opts[i] = context; 557 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT; 558 } 559 if (sbsec->flags & ROOTCONTEXT_MNT) { 560 struct inode *root = sbsec->sb->s_root->d_inode; 561 struct inode_security_struct *isec = root->i_security; 562 563 rc = security_sid_to_context(isec->sid, &context, &len); 564 if (rc) 565 goto out_free; 566 opts->mnt_opts[i] = context; 567 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT; 568 } 569 if (sbsec->flags & SBLABEL_MNT) { 570 opts->mnt_opts[i] = NULL; 571 opts->mnt_opts_flags[i++] = SBLABEL_MNT; 572 } 573 574 BUG_ON(i != opts->num_mnt_opts); 575 576 return 0; 577 578 out_free: 579 security_free_mnt_opts(opts); 580 return rc; 581 } 582 583 static int bad_option(struct superblock_security_struct *sbsec, char flag, 584 u32 old_sid, u32 new_sid) 585 { 586 char mnt_flags = sbsec->flags & SE_MNTMASK; 587 588 /* check if the old mount command had the same options */ 589 if (sbsec->flags & SE_SBINITIALIZED) 590 if (!(sbsec->flags & flag) || 591 (old_sid != new_sid)) 592 return 1; 593 594 /* check if we were passed the same options twice, 595 * aka someone passed context=a,context=b 596 */ 597 if (!(sbsec->flags & SE_SBINITIALIZED)) 598 if (mnt_flags & flag) 599 return 1; 600 return 0; 601 } 602 603 /* 604 * Allow filesystems with binary mount data to explicitly set mount point 605 * labeling information. 606 */ 607 static int selinux_set_mnt_opts(struct super_block *sb, 608 struct security_mnt_opts *opts, 609 unsigned long kern_flags, 610 unsigned long *set_kern_flags) 611 { 612 const struct cred *cred = current_cred(); 613 int rc = 0, i; 614 struct superblock_security_struct *sbsec = sb->s_security; 615 const char *name = sb->s_type->name; 616 struct inode *inode = sbsec->sb->s_root->d_inode; 617 struct inode_security_struct *root_isec = inode->i_security; 618 u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0; 619 u32 defcontext_sid = 0; 620 char **mount_options = opts->mnt_opts; 621 int *flags = opts->mnt_opts_flags; 622 int num_opts = opts->num_mnt_opts; 623 624 mutex_lock(&sbsec->lock); 625 626 if (!ss_initialized) { 627 if (!num_opts) { 628 /* Defer initialization until selinux_complete_init, 629 after the initial policy is loaded and the security 630 server is ready to handle calls. */ 631 goto out; 632 } 633 rc = -EINVAL; 634 printk(KERN_WARNING "SELinux: Unable to set superblock options " 635 "before the security server is initialized\n"); 636 goto out; 637 } 638 if (kern_flags && !set_kern_flags) { 639 /* Specifying internal flags without providing a place to 640 * place the results is not allowed */ 641 rc = -EINVAL; 642 goto out; 643 } 644 645 /* 646 * Binary mount data FS will come through this function twice. Once 647 * from an explicit call and once from the generic calls from the vfs. 648 * Since the generic VFS calls will not contain any security mount data 649 * we need to skip the double mount verification. 650 * 651 * This does open a hole in which we will not notice if the first 652 * mount using this sb set explict options and a second mount using 653 * this sb does not set any security options. (The first options 654 * will be used for both mounts) 655 */ 656 if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) 657 && (num_opts == 0)) 658 goto out; 659 660 /* 661 * parse the mount options, check if they are valid sids. 662 * also check if someone is trying to mount the same sb more 663 * than once with different security options. 664 */ 665 for (i = 0; i < num_opts; i++) { 666 u32 sid; 667 668 if (flags[i] == SBLABEL_MNT) 669 continue; 670 rc = security_context_to_sid(mount_options[i], 671 strlen(mount_options[i]), &sid, GFP_KERNEL); 672 if (rc) { 673 printk(KERN_WARNING "SELinux: security_context_to_sid" 674 "(%s) failed for (dev %s, type %s) errno=%d\n", 675 mount_options[i], sb->s_id, name, rc); 676 goto out; 677 } 678 switch (flags[i]) { 679 case FSCONTEXT_MNT: 680 fscontext_sid = sid; 681 682 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, 683 fscontext_sid)) 684 goto out_double_mount; 685 686 sbsec->flags |= FSCONTEXT_MNT; 687 break; 688 case CONTEXT_MNT: 689 context_sid = sid; 690 691 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, 692 context_sid)) 693 goto out_double_mount; 694 695 sbsec->flags |= CONTEXT_MNT; 696 break; 697 case ROOTCONTEXT_MNT: 698 rootcontext_sid = sid; 699 700 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, 701 rootcontext_sid)) 702 goto out_double_mount; 703 704 sbsec->flags |= ROOTCONTEXT_MNT; 705 706 break; 707 case DEFCONTEXT_MNT: 708 defcontext_sid = sid; 709 710 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, 711 defcontext_sid)) 712 goto out_double_mount; 713 714 sbsec->flags |= DEFCONTEXT_MNT; 715 716 break; 717 default: 718 rc = -EINVAL; 719 goto out; 720 } 721 } 722 723 if (sbsec->flags & SE_SBINITIALIZED) { 724 /* previously mounted with options, but not on this attempt? */ 725 if ((sbsec->flags & SE_MNTMASK) && !num_opts) 726 goto out_double_mount; 727 rc = 0; 728 goto out; 729 } 730 731 if (strcmp(sb->s_type->name, "proc") == 0) 732 sbsec->flags |= SE_SBPROC; 733 734 if (!sbsec->behavior) { 735 /* 736 * Determine the labeling behavior to use for this 737 * filesystem type. 738 */ 739 rc = security_fs_use(sb); 740 if (rc) { 741 printk(KERN_WARNING 742 "%s: security_fs_use(%s) returned %d\n", 743 __func__, sb->s_type->name, rc); 744 goto out; 745 } 746 } 747 /* sets the context of the superblock for the fs being mounted. */ 748 if (fscontext_sid) { 749 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred); 750 if (rc) 751 goto out; 752 753 sbsec->sid = fscontext_sid; 754 } 755 756 /* 757 * Switch to using mount point labeling behavior. 758 * sets the label used on all file below the mountpoint, and will set 759 * the superblock context if not already set. 760 */ 761 if (kern_flags & SECURITY_LSM_NATIVE_LABELS && !context_sid) { 762 sbsec->behavior = SECURITY_FS_USE_NATIVE; 763 *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; 764 } 765 766 if (context_sid) { 767 if (!fscontext_sid) { 768 rc = may_context_mount_sb_relabel(context_sid, sbsec, 769 cred); 770 if (rc) 771 goto out; 772 sbsec->sid = context_sid; 773 } else { 774 rc = may_context_mount_inode_relabel(context_sid, sbsec, 775 cred); 776 if (rc) 777 goto out; 778 } 779 if (!rootcontext_sid) 780 rootcontext_sid = context_sid; 781 782 sbsec->mntpoint_sid = context_sid; 783 sbsec->behavior = SECURITY_FS_USE_MNTPOINT; 784 } 785 786 if (rootcontext_sid) { 787 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec, 788 cred); 789 if (rc) 790 goto out; 791 792 root_isec->sid = rootcontext_sid; 793 root_isec->initialized = 1; 794 } 795 796 if (defcontext_sid) { 797 if (sbsec->behavior != SECURITY_FS_USE_XATTR && 798 sbsec->behavior != SECURITY_FS_USE_NATIVE) { 799 rc = -EINVAL; 800 printk(KERN_WARNING "SELinux: defcontext option is " 801 "invalid for this filesystem type\n"); 802 goto out; 803 } 804 805 if (defcontext_sid != sbsec->def_sid) { 806 rc = may_context_mount_inode_relabel(defcontext_sid, 807 sbsec, cred); 808 if (rc) 809 goto out; 810 } 811 812 sbsec->def_sid = defcontext_sid; 813 } 814 815 rc = sb_finish_set_opts(sb); 816 out: 817 mutex_unlock(&sbsec->lock); 818 return rc; 819 out_double_mount: 820 rc = -EINVAL; 821 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, different " 822 "security settings for (dev %s, type %s)\n", sb->s_id, name); 823 goto out; 824 } 825 826 static int selinux_cmp_sb_context(const struct super_block *oldsb, 827 const struct super_block *newsb) 828 { 829 struct superblock_security_struct *old = oldsb->s_security; 830 struct superblock_security_struct *new = newsb->s_security; 831 char oldflags = old->flags & SE_MNTMASK; 832 char newflags = new->flags & SE_MNTMASK; 833 834 if (oldflags != newflags) 835 goto mismatch; 836 if ((oldflags & FSCONTEXT_MNT) && old->sid != new->sid) 837 goto mismatch; 838 if ((oldflags & CONTEXT_MNT) && old->mntpoint_sid != new->mntpoint_sid) 839 goto mismatch; 840 if ((oldflags & DEFCONTEXT_MNT) && old->def_sid != new->def_sid) 841 goto mismatch; 842 if (oldflags & ROOTCONTEXT_MNT) { 843 struct inode_security_struct *oldroot = oldsb->s_root->d_inode->i_security; 844 struct inode_security_struct *newroot = newsb->s_root->d_inode->i_security; 845 if (oldroot->sid != newroot->sid) 846 goto mismatch; 847 } 848 return 0; 849 mismatch: 850 printk(KERN_WARNING "SELinux: mount invalid. Same superblock, " 851 "different security settings for (dev %s, " 852 "type %s)\n", newsb->s_id, newsb->s_type->name); 853 return -EBUSY; 854 } 855 856 static int selinux_sb_clone_mnt_opts(const struct super_block *oldsb, 857 struct super_block *newsb) 858 { 859 const struct superblock_security_struct *oldsbsec = oldsb->s_security; 860 struct superblock_security_struct *newsbsec = newsb->s_security; 861 862 int set_fscontext = (oldsbsec->flags & FSCONTEXT_MNT); 863 int set_context = (oldsbsec->flags & CONTEXT_MNT); 864 int set_rootcontext = (oldsbsec->flags & ROOTCONTEXT_MNT); 865 866 /* 867 * if the parent was able to be mounted it clearly had no special lsm 868 * mount options. thus we can safely deal with this superblock later 869 */ 870 if (!ss_initialized) 871 return 0; 872 873 /* how can we clone if the old one wasn't set up?? */ 874 BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED)); 875 876 /* if fs is reusing a sb, make sure that the contexts match */ 877 if (newsbsec->flags & SE_SBINITIALIZED) 878 return selinux_cmp_sb_context(oldsb, newsb); 879 880 mutex_lock(&newsbsec->lock); 881 882 newsbsec->flags = oldsbsec->flags; 883 884 newsbsec->sid = oldsbsec->sid; 885 newsbsec->def_sid = oldsbsec->def_sid; 886 newsbsec->behavior = oldsbsec->behavior; 887 888 if (set_context) { 889 u32 sid = oldsbsec->mntpoint_sid; 890 891 if (!set_fscontext) 892 newsbsec->sid = sid; 893 if (!set_rootcontext) { 894 struct inode *newinode = newsb->s_root->d_inode; 895 struct inode_security_struct *newisec = newinode->i_security; 896 newisec->sid = sid; 897 } 898 newsbsec->mntpoint_sid = sid; 899 } 900 if (set_rootcontext) { 901 const struct inode *oldinode = oldsb->s_root->d_inode; 902 const struct inode_security_struct *oldisec = oldinode->i_security; 903 struct inode *newinode = newsb->s_root->d_inode; 904 struct inode_security_struct *newisec = newinode->i_security; 905 906 newisec->sid = oldisec->sid; 907 } 908 909 sb_finish_set_opts(newsb); 910 mutex_unlock(&newsbsec->lock); 911 return 0; 912 } 913 914 static int selinux_parse_opts_str(char *options, 915 struct security_mnt_opts *opts) 916 { 917 char *p; 918 char *context = NULL, *defcontext = NULL; 919 char *fscontext = NULL, *rootcontext = NULL; 920 int rc, num_mnt_opts = 0; 921 922 opts->num_mnt_opts = 0; 923 924 /* Standard string-based options. */ 925 while ((p = strsep(&options, "|")) != NULL) { 926 int token; 927 substring_t args[MAX_OPT_ARGS]; 928 929 if (!*p) 930 continue; 931 932 token = match_token(p, tokens, args); 933 934 switch (token) { 935 case Opt_context: 936 if (context || defcontext) { 937 rc = -EINVAL; 938 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 939 goto out_err; 940 } 941 context = match_strdup(&args[0]); 942 if (!context) { 943 rc = -ENOMEM; 944 goto out_err; 945 } 946 break; 947 948 case Opt_fscontext: 949 if (fscontext) { 950 rc = -EINVAL; 951 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 952 goto out_err; 953 } 954 fscontext = match_strdup(&args[0]); 955 if (!fscontext) { 956 rc = -ENOMEM; 957 goto out_err; 958 } 959 break; 960 961 case Opt_rootcontext: 962 if (rootcontext) { 963 rc = -EINVAL; 964 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 965 goto out_err; 966 } 967 rootcontext = match_strdup(&args[0]); 968 if (!rootcontext) { 969 rc = -ENOMEM; 970 goto out_err; 971 } 972 break; 973 974 case Opt_defcontext: 975 if (context || defcontext) { 976 rc = -EINVAL; 977 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG); 978 goto out_err; 979 } 980 defcontext = match_strdup(&args[0]); 981 if (!defcontext) { 982 rc = -ENOMEM; 983 goto out_err; 984 } 985 break; 986 case Opt_labelsupport: 987 break; 988 default: 989 rc = -EINVAL; 990 printk(KERN_WARNING "SELinux: unknown mount option\n"); 991 goto out_err; 992 993 } 994 } 995 996 rc = -ENOMEM; 997 opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC); 998 if (!opts->mnt_opts) 999 goto out_err; 1000 1001 opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC); 1002 if (!opts->mnt_opts_flags) { 1003 kfree(opts->mnt_opts); 1004 goto out_err; 1005 } 1006 1007 if (fscontext) { 1008 opts->mnt_opts[num_mnt_opts] = fscontext; 1009 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT; 1010 } 1011 if (context) { 1012 opts->mnt_opts[num_mnt_opts] = context; 1013 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT; 1014 } 1015 if (rootcontext) { 1016 opts->mnt_opts[num_mnt_opts] = rootcontext; 1017 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT; 1018 } 1019 if (defcontext) { 1020 opts->mnt_opts[num_mnt_opts] = defcontext; 1021 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT; 1022 } 1023 1024 opts->num_mnt_opts = num_mnt_opts; 1025 return 0; 1026 1027 out_err: 1028 kfree(context); 1029 kfree(defcontext); 1030 kfree(fscontext); 1031 kfree(rootcontext); 1032 return rc; 1033 } 1034 /* 1035 * string mount options parsing and call set the sbsec 1036 */ 1037 static int superblock_doinit(struct super_block *sb, void *data) 1038 { 1039 int rc = 0; 1040 char *options = data; 1041 struct security_mnt_opts opts; 1042 1043 security_init_mnt_opts(&opts); 1044 1045 if (!data) 1046 goto out; 1047 1048 BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA); 1049 1050 rc = selinux_parse_opts_str(options, &opts); 1051 if (rc) 1052 goto out_err; 1053 1054 out: 1055 rc = selinux_set_mnt_opts(sb, &opts, 0, NULL); 1056 1057 out_err: 1058 security_free_mnt_opts(&opts); 1059 return rc; 1060 } 1061 1062 static void selinux_write_opts(struct seq_file *m, 1063 struct security_mnt_opts *opts) 1064 { 1065 int i; 1066 char *prefix; 1067 1068 for (i = 0; i < opts->num_mnt_opts; i++) { 1069 char *has_comma; 1070 1071 if (opts->mnt_opts[i]) 1072 has_comma = strchr(opts->mnt_opts[i], ','); 1073 else 1074 has_comma = NULL; 1075 1076 switch (opts->mnt_opts_flags[i]) { 1077 case CONTEXT_MNT: 1078 prefix = CONTEXT_STR; 1079 break; 1080 case FSCONTEXT_MNT: 1081 prefix = FSCONTEXT_STR; 1082 break; 1083 case ROOTCONTEXT_MNT: 1084 prefix = ROOTCONTEXT_STR; 1085 break; 1086 case DEFCONTEXT_MNT: 1087 prefix = DEFCONTEXT_STR; 1088 break; 1089 case SBLABEL_MNT: 1090 seq_putc(m, ','); 1091 seq_puts(m, LABELSUPP_STR); 1092 continue; 1093 default: 1094 BUG(); 1095 return; 1096 }; 1097 /* we need a comma before each option */ 1098 seq_putc(m, ','); 1099 seq_puts(m, prefix); 1100 if (has_comma) 1101 seq_putc(m, '\"'); 1102 seq_puts(m, opts->mnt_opts[i]); 1103 if (has_comma) 1104 seq_putc(m, '\"'); 1105 } 1106 } 1107 1108 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb) 1109 { 1110 struct security_mnt_opts opts; 1111 int rc; 1112 1113 rc = selinux_get_mnt_opts(sb, &opts); 1114 if (rc) { 1115 /* before policy load we may get EINVAL, don't show anything */ 1116 if (rc == -EINVAL) 1117 rc = 0; 1118 return rc; 1119 } 1120 1121 selinux_write_opts(m, &opts); 1122 1123 security_free_mnt_opts(&opts); 1124 1125 return rc; 1126 } 1127 1128 static inline u16 inode_mode_to_security_class(umode_t mode) 1129 { 1130 switch (mode & S_IFMT) { 1131 case S_IFSOCK: 1132 return SECCLASS_SOCK_FILE; 1133 case S_IFLNK: 1134 return SECCLASS_LNK_FILE; 1135 case S_IFREG: 1136 return SECCLASS_FILE; 1137 case S_IFBLK: 1138 return SECCLASS_BLK_FILE; 1139 case S_IFDIR: 1140 return SECCLASS_DIR; 1141 case S_IFCHR: 1142 return SECCLASS_CHR_FILE; 1143 case S_IFIFO: 1144 return SECCLASS_FIFO_FILE; 1145 1146 } 1147 1148 return SECCLASS_FILE; 1149 } 1150 1151 static inline int default_protocol_stream(int protocol) 1152 { 1153 return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP); 1154 } 1155 1156 static inline int default_protocol_dgram(int protocol) 1157 { 1158 return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP); 1159 } 1160 1161 static inline u16 socket_type_to_security_class(int family, int type, int protocol) 1162 { 1163 switch (family) { 1164 case PF_UNIX: 1165 switch (type) { 1166 case SOCK_STREAM: 1167 case SOCK_SEQPACKET: 1168 return SECCLASS_UNIX_STREAM_SOCKET; 1169 case SOCK_DGRAM: 1170 return SECCLASS_UNIX_DGRAM_SOCKET; 1171 } 1172 break; 1173 case PF_INET: 1174 case PF_INET6: 1175 switch (type) { 1176 case SOCK_STREAM: 1177 if (default_protocol_stream(protocol)) 1178 return SECCLASS_TCP_SOCKET; 1179 else 1180 return SECCLASS_RAWIP_SOCKET; 1181 case SOCK_DGRAM: 1182 if (default_protocol_dgram(protocol)) 1183 return SECCLASS_UDP_SOCKET; 1184 else 1185 return SECCLASS_RAWIP_SOCKET; 1186 case SOCK_DCCP: 1187 return SECCLASS_DCCP_SOCKET; 1188 default: 1189 return SECCLASS_RAWIP_SOCKET; 1190 } 1191 break; 1192 case PF_NETLINK: 1193 switch (protocol) { 1194 case NETLINK_ROUTE: 1195 return SECCLASS_NETLINK_ROUTE_SOCKET; 1196 case NETLINK_FIREWALL: 1197 return SECCLASS_NETLINK_FIREWALL_SOCKET; 1198 case NETLINK_SOCK_DIAG: 1199 return SECCLASS_NETLINK_TCPDIAG_SOCKET; 1200 case NETLINK_NFLOG: 1201 return SECCLASS_NETLINK_NFLOG_SOCKET; 1202 case NETLINK_XFRM: 1203 return SECCLASS_NETLINK_XFRM_SOCKET; 1204 case NETLINK_SELINUX: 1205 return SECCLASS_NETLINK_SELINUX_SOCKET; 1206 case NETLINK_AUDIT: 1207 return SECCLASS_NETLINK_AUDIT_SOCKET; 1208 case NETLINK_IP6_FW: 1209 return SECCLASS_NETLINK_IP6FW_SOCKET; 1210 case NETLINK_DNRTMSG: 1211 return SECCLASS_NETLINK_DNRT_SOCKET; 1212 case NETLINK_KOBJECT_UEVENT: 1213 return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET; 1214 default: 1215 return SECCLASS_NETLINK_SOCKET; 1216 } 1217 case PF_PACKET: 1218 return SECCLASS_PACKET_SOCKET; 1219 case PF_KEY: 1220 return SECCLASS_KEY_SOCKET; 1221 case PF_APPLETALK: 1222 return SECCLASS_APPLETALK_SOCKET; 1223 } 1224 1225 return SECCLASS_SOCKET; 1226 } 1227 1228 #ifdef CONFIG_PROC_FS 1229 static int selinux_proc_get_sid(struct dentry *dentry, 1230 u16 tclass, 1231 u32 *sid) 1232 { 1233 int rc; 1234 char *buffer, *path; 1235 1236 buffer = (char *)__get_free_page(GFP_KERNEL); 1237 if (!buffer) 1238 return -ENOMEM; 1239 1240 path = dentry_path_raw(dentry, buffer, PAGE_SIZE); 1241 if (IS_ERR(path)) 1242 rc = PTR_ERR(path); 1243 else { 1244 /* each process gets a /proc/PID/ entry. Strip off the 1245 * PID part to get a valid selinux labeling. 1246 * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */ 1247 while (path[1] >= '0' && path[1] <= '9') { 1248 path[1] = '/'; 1249 path++; 1250 } 1251 rc = security_genfs_sid("proc", path, tclass, sid); 1252 } 1253 free_page((unsigned long)buffer); 1254 return rc; 1255 } 1256 #else 1257 static int selinux_proc_get_sid(struct dentry *dentry, 1258 u16 tclass, 1259 u32 *sid) 1260 { 1261 return -EINVAL; 1262 } 1263 #endif 1264 1265 /* The inode's security attributes must be initialized before first use. */ 1266 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry) 1267 { 1268 struct superblock_security_struct *sbsec = NULL; 1269 struct inode_security_struct *isec = inode->i_security; 1270 u32 sid; 1271 struct dentry *dentry; 1272 #define INITCONTEXTLEN 255 1273 char *context = NULL; 1274 unsigned len = 0; 1275 int rc = 0; 1276 1277 if (isec->initialized) 1278 goto out; 1279 1280 mutex_lock(&isec->lock); 1281 if (isec->initialized) 1282 goto out_unlock; 1283 1284 sbsec = inode->i_sb->s_security; 1285 if (!(sbsec->flags & SE_SBINITIALIZED)) { 1286 /* Defer initialization until selinux_complete_init, 1287 after the initial policy is loaded and the security 1288 server is ready to handle calls. */ 1289 spin_lock(&sbsec->isec_lock); 1290 if (list_empty(&isec->list)) 1291 list_add(&isec->list, &sbsec->isec_head); 1292 spin_unlock(&sbsec->isec_lock); 1293 goto out_unlock; 1294 } 1295 1296 switch (sbsec->behavior) { 1297 case SECURITY_FS_USE_NATIVE: 1298 break; 1299 case SECURITY_FS_USE_XATTR: 1300 if (!inode->i_op->getxattr) { 1301 isec->sid = sbsec->def_sid; 1302 break; 1303 } 1304 1305 /* Need a dentry, since the xattr API requires one. 1306 Life would be simpler if we could just pass the inode. */ 1307 if (opt_dentry) { 1308 /* Called from d_instantiate or d_splice_alias. */ 1309 dentry = dget(opt_dentry); 1310 } else { 1311 /* Called from selinux_complete_init, try to find a dentry. */ 1312 dentry = d_find_alias(inode); 1313 } 1314 if (!dentry) { 1315 /* 1316 * this is can be hit on boot when a file is accessed 1317 * before the policy is loaded. When we load policy we 1318 * may find inodes that have no dentry on the 1319 * sbsec->isec_head list. No reason to complain as these 1320 * will get fixed up the next time we go through 1321 * inode_doinit with a dentry, before these inodes could 1322 * be used again by userspace. 1323 */ 1324 goto out_unlock; 1325 } 1326 1327 len = INITCONTEXTLEN; 1328 context = kmalloc(len+1, GFP_NOFS); 1329 if (!context) { 1330 rc = -ENOMEM; 1331 dput(dentry); 1332 goto out_unlock; 1333 } 1334 context[len] = '\0'; 1335 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, 1336 context, len); 1337 if (rc == -ERANGE) { 1338 kfree(context); 1339 1340 /* Need a larger buffer. Query for the right size. */ 1341 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX, 1342 NULL, 0); 1343 if (rc < 0) { 1344 dput(dentry); 1345 goto out_unlock; 1346 } 1347 len = rc; 1348 context = kmalloc(len+1, GFP_NOFS); 1349 if (!context) { 1350 rc = -ENOMEM; 1351 dput(dentry); 1352 goto out_unlock; 1353 } 1354 context[len] = '\0'; 1355 rc = inode->i_op->getxattr(dentry, 1356 XATTR_NAME_SELINUX, 1357 context, len); 1358 } 1359 dput(dentry); 1360 if (rc < 0) { 1361 if (rc != -ENODATA) { 1362 printk(KERN_WARNING "SELinux: %s: getxattr returned " 1363 "%d for dev=%s ino=%ld\n", __func__, 1364 -rc, inode->i_sb->s_id, inode->i_ino); 1365 kfree(context); 1366 goto out_unlock; 1367 } 1368 /* Map ENODATA to the default file SID */ 1369 sid = sbsec->def_sid; 1370 rc = 0; 1371 } else { 1372 rc = security_context_to_sid_default(context, rc, &sid, 1373 sbsec->def_sid, 1374 GFP_NOFS); 1375 if (rc) { 1376 char *dev = inode->i_sb->s_id; 1377 unsigned long ino = inode->i_ino; 1378 1379 if (rc == -EINVAL) { 1380 if (printk_ratelimit()) 1381 printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid " 1382 "context=%s. This indicates you may need to relabel the inode or the " 1383 "filesystem in question.\n", ino, dev, context); 1384 } else { 1385 printk(KERN_WARNING "SELinux: %s: context_to_sid(%s) " 1386 "returned %d for dev=%s ino=%ld\n", 1387 __func__, context, -rc, dev, ino); 1388 } 1389 kfree(context); 1390 /* Leave with the unlabeled SID */ 1391 rc = 0; 1392 break; 1393 } 1394 } 1395 kfree(context); 1396 isec->sid = sid; 1397 break; 1398 case SECURITY_FS_USE_TASK: 1399 isec->sid = isec->task_sid; 1400 break; 1401 case SECURITY_FS_USE_TRANS: 1402 /* Default to the fs SID. */ 1403 isec->sid = sbsec->sid; 1404 1405 /* Try to obtain a transition SID. */ 1406 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1407 rc = security_transition_sid(isec->task_sid, sbsec->sid, 1408 isec->sclass, NULL, &sid); 1409 if (rc) 1410 goto out_unlock; 1411 isec->sid = sid; 1412 break; 1413 case SECURITY_FS_USE_MNTPOINT: 1414 isec->sid = sbsec->mntpoint_sid; 1415 break; 1416 default: 1417 /* Default to the fs superblock SID. */ 1418 isec->sid = sbsec->sid; 1419 1420 if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) { 1421 /* We must have a dentry to determine the label on 1422 * procfs inodes */ 1423 if (opt_dentry) 1424 /* Called from d_instantiate or 1425 * d_splice_alias. */ 1426 dentry = dget(opt_dentry); 1427 else 1428 /* Called from selinux_complete_init, try to 1429 * find a dentry. */ 1430 dentry = d_find_alias(inode); 1431 /* 1432 * This can be hit on boot when a file is accessed 1433 * before the policy is loaded. When we load policy we 1434 * may find inodes that have no dentry on the 1435 * sbsec->isec_head list. No reason to complain as 1436 * these will get fixed up the next time we go through 1437 * inode_doinit() with a dentry, before these inodes 1438 * could be used again by userspace. 1439 */ 1440 if (!dentry) 1441 goto out_unlock; 1442 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1443 rc = selinux_proc_get_sid(dentry, isec->sclass, &sid); 1444 dput(dentry); 1445 if (rc) 1446 goto out_unlock; 1447 isec->sid = sid; 1448 } 1449 break; 1450 } 1451 1452 isec->initialized = 1; 1453 1454 out_unlock: 1455 mutex_unlock(&isec->lock); 1456 out: 1457 if (isec->sclass == SECCLASS_FILE) 1458 isec->sclass = inode_mode_to_security_class(inode->i_mode); 1459 return rc; 1460 } 1461 1462 /* Convert a Linux signal to an access vector. */ 1463 static inline u32 signal_to_av(int sig) 1464 { 1465 u32 perm = 0; 1466 1467 switch (sig) { 1468 case SIGCHLD: 1469 /* Commonly granted from child to parent. */ 1470 perm = PROCESS__SIGCHLD; 1471 break; 1472 case SIGKILL: 1473 /* Cannot be caught or ignored */ 1474 perm = PROCESS__SIGKILL; 1475 break; 1476 case SIGSTOP: 1477 /* Cannot be caught or ignored */ 1478 perm = PROCESS__SIGSTOP; 1479 break; 1480 default: 1481 /* All other signals. */ 1482 perm = PROCESS__SIGNAL; 1483 break; 1484 } 1485 1486 return perm; 1487 } 1488 1489 /* 1490 * Check permission between a pair of credentials 1491 * fork check, ptrace check, etc. 1492 */ 1493 static int cred_has_perm(const struct cred *actor, 1494 const struct cred *target, 1495 u32 perms) 1496 { 1497 u32 asid = cred_sid(actor), tsid = cred_sid(target); 1498 1499 return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL); 1500 } 1501 1502 /* 1503 * Check permission between a pair of tasks, e.g. signal checks, 1504 * fork check, ptrace check, etc. 1505 * tsk1 is the actor and tsk2 is the target 1506 * - this uses the default subjective creds of tsk1 1507 */ 1508 static int task_has_perm(const struct task_struct *tsk1, 1509 const struct task_struct *tsk2, 1510 u32 perms) 1511 { 1512 const struct task_security_struct *__tsec1, *__tsec2; 1513 u32 sid1, sid2; 1514 1515 rcu_read_lock(); 1516 __tsec1 = __task_cred(tsk1)->security; sid1 = __tsec1->sid; 1517 __tsec2 = __task_cred(tsk2)->security; sid2 = __tsec2->sid; 1518 rcu_read_unlock(); 1519 return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL); 1520 } 1521 1522 /* 1523 * Check permission between current and another task, e.g. signal checks, 1524 * fork check, ptrace check, etc. 1525 * current is the actor and tsk2 is the target 1526 * - this uses current's subjective creds 1527 */ 1528 static int current_has_perm(const struct task_struct *tsk, 1529 u32 perms) 1530 { 1531 u32 sid, tsid; 1532 1533 sid = current_sid(); 1534 tsid = task_sid(tsk); 1535 return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL); 1536 } 1537 1538 #if CAP_LAST_CAP > 63 1539 #error Fix SELinux to handle capabilities > 63. 1540 #endif 1541 1542 /* Check whether a task is allowed to use a capability. */ 1543 static int cred_has_capability(const struct cred *cred, 1544 int cap, int audit) 1545 { 1546 struct common_audit_data ad; 1547 struct av_decision avd; 1548 u16 sclass; 1549 u32 sid = cred_sid(cred); 1550 u32 av = CAP_TO_MASK(cap); 1551 int rc; 1552 1553 ad.type = LSM_AUDIT_DATA_CAP; 1554 ad.u.cap = cap; 1555 1556 switch (CAP_TO_INDEX(cap)) { 1557 case 0: 1558 sclass = SECCLASS_CAPABILITY; 1559 break; 1560 case 1: 1561 sclass = SECCLASS_CAPABILITY2; 1562 break; 1563 default: 1564 printk(KERN_ERR 1565 "SELinux: out of range capability %d\n", cap); 1566 BUG(); 1567 return -EINVAL; 1568 } 1569 1570 rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd); 1571 if (audit == SECURITY_CAP_AUDIT) { 1572 int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad); 1573 if (rc2) 1574 return rc2; 1575 } 1576 return rc; 1577 } 1578 1579 /* Check whether a task is allowed to use a system operation. */ 1580 static int task_has_system(struct task_struct *tsk, 1581 u32 perms) 1582 { 1583 u32 sid = task_sid(tsk); 1584 1585 return avc_has_perm(sid, SECINITSID_KERNEL, 1586 SECCLASS_SYSTEM, perms, NULL); 1587 } 1588 1589 /* Check whether a task has a particular permission to an inode. 1590 The 'adp' parameter is optional and allows other audit 1591 data to be passed (e.g. the dentry). */ 1592 static int inode_has_perm(const struct cred *cred, 1593 struct inode *inode, 1594 u32 perms, 1595 struct common_audit_data *adp) 1596 { 1597 struct inode_security_struct *isec; 1598 u32 sid; 1599 1600 validate_creds(cred); 1601 1602 if (unlikely(IS_PRIVATE(inode))) 1603 return 0; 1604 1605 sid = cred_sid(cred); 1606 isec = inode->i_security; 1607 1608 return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp); 1609 } 1610 1611 /* Same as inode_has_perm, but pass explicit audit data containing 1612 the dentry to help the auditing code to more easily generate the 1613 pathname if needed. */ 1614 static inline int dentry_has_perm(const struct cred *cred, 1615 struct dentry *dentry, 1616 u32 av) 1617 { 1618 struct inode *inode = dentry->d_inode; 1619 struct common_audit_data ad; 1620 1621 ad.type = LSM_AUDIT_DATA_DENTRY; 1622 ad.u.dentry = dentry; 1623 return inode_has_perm(cred, inode, av, &ad); 1624 } 1625 1626 /* Same as inode_has_perm, but pass explicit audit data containing 1627 the path to help the auditing code to more easily generate the 1628 pathname if needed. */ 1629 static inline int path_has_perm(const struct cred *cred, 1630 struct path *path, 1631 u32 av) 1632 { 1633 struct inode *inode = path->dentry->d_inode; 1634 struct common_audit_data ad; 1635 1636 ad.type = LSM_AUDIT_DATA_PATH; 1637 ad.u.path = *path; 1638 return inode_has_perm(cred, inode, av, &ad); 1639 } 1640 1641 /* Same as path_has_perm, but uses the inode from the file struct. */ 1642 static inline int file_path_has_perm(const struct cred *cred, 1643 struct file *file, 1644 u32 av) 1645 { 1646 struct common_audit_data ad; 1647 1648 ad.type = LSM_AUDIT_DATA_PATH; 1649 ad.u.path = file->f_path; 1650 return inode_has_perm(cred, file_inode(file), av, &ad); 1651 } 1652 1653 /* Check whether a task can use an open file descriptor to 1654 access an inode in a given way. Check access to the 1655 descriptor itself, and then use dentry_has_perm to 1656 check a particular permission to the file. 1657 Access to the descriptor is implicitly granted if it 1658 has the same SID as the process. If av is zero, then 1659 access to the file is not checked, e.g. for cases 1660 where only the descriptor is affected like seek. */ 1661 static int file_has_perm(const struct cred *cred, 1662 struct file *file, 1663 u32 av) 1664 { 1665 struct file_security_struct *fsec = file->f_security; 1666 struct inode *inode = file_inode(file); 1667 struct common_audit_data ad; 1668 u32 sid = cred_sid(cred); 1669 int rc; 1670 1671 ad.type = LSM_AUDIT_DATA_PATH; 1672 ad.u.path = file->f_path; 1673 1674 if (sid != fsec->sid) { 1675 rc = avc_has_perm(sid, fsec->sid, 1676 SECCLASS_FD, 1677 FD__USE, 1678 &ad); 1679 if (rc) 1680 goto out; 1681 } 1682 1683 /* av is zero if only checking access to the descriptor. */ 1684 rc = 0; 1685 if (av) 1686 rc = inode_has_perm(cred, inode, av, &ad); 1687 1688 out: 1689 return rc; 1690 } 1691 1692 /* Check whether a task can create a file. */ 1693 static int may_create(struct inode *dir, 1694 struct dentry *dentry, 1695 u16 tclass) 1696 { 1697 const struct task_security_struct *tsec = current_security(); 1698 struct inode_security_struct *dsec; 1699 struct superblock_security_struct *sbsec; 1700 u32 sid, newsid; 1701 struct common_audit_data ad; 1702 int rc; 1703 1704 dsec = dir->i_security; 1705 sbsec = dir->i_sb->s_security; 1706 1707 sid = tsec->sid; 1708 newsid = tsec->create_sid; 1709 1710 ad.type = LSM_AUDIT_DATA_DENTRY; 1711 ad.u.dentry = dentry; 1712 1713 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, 1714 DIR__ADD_NAME | DIR__SEARCH, 1715 &ad); 1716 if (rc) 1717 return rc; 1718 1719 if (!newsid || !(sbsec->flags & SBLABEL_MNT)) { 1720 rc = security_transition_sid(sid, dsec->sid, tclass, 1721 &dentry->d_name, &newsid); 1722 if (rc) 1723 return rc; 1724 } 1725 1726 rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad); 1727 if (rc) 1728 return rc; 1729 1730 return avc_has_perm(newsid, sbsec->sid, 1731 SECCLASS_FILESYSTEM, 1732 FILESYSTEM__ASSOCIATE, &ad); 1733 } 1734 1735 /* Check whether a task can create a key. */ 1736 static int may_create_key(u32 ksid, 1737 struct task_struct *ctx) 1738 { 1739 u32 sid = task_sid(ctx); 1740 1741 return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL); 1742 } 1743 1744 #define MAY_LINK 0 1745 #define MAY_UNLINK 1 1746 #define MAY_RMDIR 2 1747 1748 /* Check whether a task can link, unlink, or rmdir a file/directory. */ 1749 static int may_link(struct inode *dir, 1750 struct dentry *dentry, 1751 int kind) 1752 1753 { 1754 struct inode_security_struct *dsec, *isec; 1755 struct common_audit_data ad; 1756 u32 sid = current_sid(); 1757 u32 av; 1758 int rc; 1759 1760 dsec = dir->i_security; 1761 isec = dentry->d_inode->i_security; 1762 1763 ad.type = LSM_AUDIT_DATA_DENTRY; 1764 ad.u.dentry = dentry; 1765 1766 av = DIR__SEARCH; 1767 av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME); 1768 rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad); 1769 if (rc) 1770 return rc; 1771 1772 switch (kind) { 1773 case MAY_LINK: 1774 av = FILE__LINK; 1775 break; 1776 case MAY_UNLINK: 1777 av = FILE__UNLINK; 1778 break; 1779 case MAY_RMDIR: 1780 av = DIR__RMDIR; 1781 break; 1782 default: 1783 printk(KERN_WARNING "SELinux: %s: unrecognized kind %d\n", 1784 __func__, kind); 1785 return 0; 1786 } 1787 1788 rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad); 1789 return rc; 1790 } 1791 1792 static inline int may_rename(struct inode *old_dir, 1793 struct dentry *old_dentry, 1794 struct inode *new_dir, 1795 struct dentry *new_dentry) 1796 { 1797 struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec; 1798 struct common_audit_data ad; 1799 u32 sid = current_sid(); 1800 u32 av; 1801 int old_is_dir, new_is_dir; 1802 int rc; 1803 1804 old_dsec = old_dir->i_security; 1805 old_isec = old_dentry->d_inode->i_security; 1806 old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode); 1807 new_dsec = new_dir->i_security; 1808 1809 ad.type = LSM_AUDIT_DATA_DENTRY; 1810 1811 ad.u.dentry = old_dentry; 1812 rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR, 1813 DIR__REMOVE_NAME | DIR__SEARCH, &ad); 1814 if (rc) 1815 return rc; 1816 rc = avc_has_perm(sid, old_isec->sid, 1817 old_isec->sclass, FILE__RENAME, &ad); 1818 if (rc) 1819 return rc; 1820 if (old_is_dir && new_dir != old_dir) { 1821 rc = avc_has_perm(sid, old_isec->sid, 1822 old_isec->sclass, DIR__REPARENT, &ad); 1823 if (rc) 1824 return rc; 1825 } 1826 1827 ad.u.dentry = new_dentry; 1828 av = DIR__ADD_NAME | DIR__SEARCH; 1829 if (new_dentry->d_inode) 1830 av |= DIR__REMOVE_NAME; 1831 rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad); 1832 if (rc) 1833 return rc; 1834 if (new_dentry->d_inode) { 1835 new_isec = new_dentry->d_inode->i_security; 1836 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode); 1837 rc = avc_has_perm(sid, new_isec->sid, 1838 new_isec->sclass, 1839 (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad); 1840 if (rc) 1841 return rc; 1842 } 1843 1844 return 0; 1845 } 1846 1847 /* Check whether a task can perform a filesystem operation. */ 1848 static int superblock_has_perm(const struct cred *cred, 1849 struct super_block *sb, 1850 u32 perms, 1851 struct common_audit_data *ad) 1852 { 1853 struct superblock_security_struct *sbsec; 1854 u32 sid = cred_sid(cred); 1855 1856 sbsec = sb->s_security; 1857 return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad); 1858 } 1859 1860 /* Convert a Linux mode and permission mask to an access vector. */ 1861 static inline u32 file_mask_to_av(int mode, int mask) 1862 { 1863 u32 av = 0; 1864 1865 if (!S_ISDIR(mode)) { 1866 if (mask & MAY_EXEC) 1867 av |= FILE__EXECUTE; 1868 if (mask & MAY_READ) 1869 av |= FILE__READ; 1870 1871 if (mask & MAY_APPEND) 1872 av |= FILE__APPEND; 1873 else if (mask & MAY_WRITE) 1874 av |= FILE__WRITE; 1875 1876 } else { 1877 if (mask & MAY_EXEC) 1878 av |= DIR__SEARCH; 1879 if (mask & MAY_WRITE) 1880 av |= DIR__WRITE; 1881 if (mask & MAY_READ) 1882 av |= DIR__READ; 1883 } 1884 1885 return av; 1886 } 1887 1888 /* Convert a Linux file to an access vector. */ 1889 static inline u32 file_to_av(struct file *file) 1890 { 1891 u32 av = 0; 1892 1893 if (file->f_mode & FMODE_READ) 1894 av |= FILE__READ; 1895 if (file->f_mode & FMODE_WRITE) { 1896 if (file->f_flags & O_APPEND) 1897 av |= FILE__APPEND; 1898 else 1899 av |= FILE__WRITE; 1900 } 1901 if (!av) { 1902 /* 1903 * Special file opened with flags 3 for ioctl-only use. 1904 */ 1905 av = FILE__IOCTL; 1906 } 1907 1908 return av; 1909 } 1910 1911 /* 1912 * Convert a file to an access vector and include the correct open 1913 * open permission. 1914 */ 1915 static inline u32 open_file_to_av(struct file *file) 1916 { 1917 u32 av = file_to_av(file); 1918 1919 if (selinux_policycap_openperm) 1920 av |= FILE__OPEN; 1921 1922 return av; 1923 } 1924 1925 /* Hook functions begin here. */ 1926 1927 static int selinux_ptrace_access_check(struct task_struct *child, 1928 unsigned int mode) 1929 { 1930 int rc; 1931 1932 rc = cap_ptrace_access_check(child, mode); 1933 if (rc) 1934 return rc; 1935 1936 if (mode & PTRACE_MODE_READ) { 1937 u32 sid = current_sid(); 1938 u32 csid = task_sid(child); 1939 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL); 1940 } 1941 1942 return current_has_perm(child, PROCESS__PTRACE); 1943 } 1944 1945 static int selinux_ptrace_traceme(struct task_struct *parent) 1946 { 1947 int rc; 1948 1949 rc = cap_ptrace_traceme(parent); 1950 if (rc) 1951 return rc; 1952 1953 return task_has_perm(parent, current, PROCESS__PTRACE); 1954 } 1955 1956 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective, 1957 kernel_cap_t *inheritable, kernel_cap_t *permitted) 1958 { 1959 int error; 1960 1961 error = current_has_perm(target, PROCESS__GETCAP); 1962 if (error) 1963 return error; 1964 1965 return cap_capget(target, effective, inheritable, permitted); 1966 } 1967 1968 static int selinux_capset(struct cred *new, const struct cred *old, 1969 const kernel_cap_t *effective, 1970 const kernel_cap_t *inheritable, 1971 const kernel_cap_t *permitted) 1972 { 1973 int error; 1974 1975 error = cap_capset(new, old, 1976 effective, inheritable, permitted); 1977 if (error) 1978 return error; 1979 1980 return cred_has_perm(old, new, PROCESS__SETCAP); 1981 } 1982 1983 /* 1984 * (This comment used to live with the selinux_task_setuid hook, 1985 * which was removed). 1986 * 1987 * Since setuid only affects the current process, and since the SELinux 1988 * controls are not based on the Linux identity attributes, SELinux does not 1989 * need to control this operation. However, SELinux does control the use of 1990 * the CAP_SETUID and CAP_SETGID capabilities using the capable hook. 1991 */ 1992 1993 static int selinux_capable(const struct cred *cred, struct user_namespace *ns, 1994 int cap, int audit) 1995 { 1996 int rc; 1997 1998 rc = cap_capable(cred, ns, cap, audit); 1999 if (rc) 2000 return rc; 2001 2002 return cred_has_capability(cred, cap, audit); 2003 } 2004 2005 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb) 2006 { 2007 const struct cred *cred = current_cred(); 2008 int rc = 0; 2009 2010 if (!sb) 2011 return 0; 2012 2013 switch (cmds) { 2014 case Q_SYNC: 2015 case Q_QUOTAON: 2016 case Q_QUOTAOFF: 2017 case Q_SETINFO: 2018 case Q_SETQUOTA: 2019 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL); 2020 break; 2021 case Q_GETFMT: 2022 case Q_GETINFO: 2023 case Q_GETQUOTA: 2024 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL); 2025 break; 2026 default: 2027 rc = 0; /* let the kernel handle invalid cmds */ 2028 break; 2029 } 2030 return rc; 2031 } 2032 2033 static int selinux_quota_on(struct dentry *dentry) 2034 { 2035 const struct cred *cred = current_cred(); 2036 2037 return dentry_has_perm(cred, dentry, FILE__QUOTAON); 2038 } 2039 2040 static int selinux_syslog(int type) 2041 { 2042 int rc; 2043 2044 switch (type) { 2045 case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */ 2046 case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */ 2047 rc = task_has_system(current, SYSTEM__SYSLOG_READ); 2048 break; 2049 case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */ 2050 case SYSLOG_ACTION_CONSOLE_ON: /* Enable logging to console */ 2051 /* Set level of messages printed to console */ 2052 case SYSLOG_ACTION_CONSOLE_LEVEL: 2053 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE); 2054 break; 2055 case SYSLOG_ACTION_CLOSE: /* Close log */ 2056 case SYSLOG_ACTION_OPEN: /* Open log */ 2057 case SYSLOG_ACTION_READ: /* Read from log */ 2058 case SYSLOG_ACTION_READ_CLEAR: /* Read/clear last kernel messages */ 2059 case SYSLOG_ACTION_CLEAR: /* Clear ring buffer */ 2060 default: 2061 rc = task_has_system(current, SYSTEM__SYSLOG_MOD); 2062 break; 2063 } 2064 return rc; 2065 } 2066 2067 /* 2068 * Check that a process has enough memory to allocate a new virtual 2069 * mapping. 0 means there is enough memory for the allocation to 2070 * succeed and -ENOMEM implies there is not. 2071 * 2072 * Do not audit the selinux permission check, as this is applied to all 2073 * processes that allocate mappings. 2074 */ 2075 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages) 2076 { 2077 int rc, cap_sys_admin = 0; 2078 2079 rc = selinux_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN, 2080 SECURITY_CAP_NOAUDIT); 2081 if (rc == 0) 2082 cap_sys_admin = 1; 2083 2084 return __vm_enough_memory(mm, pages, cap_sys_admin); 2085 } 2086 2087 /* binprm security operations */ 2088 2089 static int selinux_bprm_set_creds(struct linux_binprm *bprm) 2090 { 2091 const struct task_security_struct *old_tsec; 2092 struct task_security_struct *new_tsec; 2093 struct inode_security_struct *isec; 2094 struct common_audit_data ad; 2095 struct inode *inode = file_inode(bprm->file); 2096 int rc; 2097 2098 rc = cap_bprm_set_creds(bprm); 2099 if (rc) 2100 return rc; 2101 2102 /* SELinux context only depends on initial program or script and not 2103 * the script interpreter */ 2104 if (bprm->cred_prepared) 2105 return 0; 2106 2107 old_tsec = current_security(); 2108 new_tsec = bprm->cred->security; 2109 isec = inode->i_security; 2110 2111 /* Default to the current task SID. */ 2112 new_tsec->sid = old_tsec->sid; 2113 new_tsec->osid = old_tsec->sid; 2114 2115 /* Reset fs, key, and sock SIDs on execve. */ 2116 new_tsec->create_sid = 0; 2117 new_tsec->keycreate_sid = 0; 2118 new_tsec->sockcreate_sid = 0; 2119 2120 if (old_tsec->exec_sid) { 2121 new_tsec->sid = old_tsec->exec_sid; 2122 /* Reset exec SID on execve. */ 2123 new_tsec->exec_sid = 0; 2124 2125 /* 2126 * Minimize confusion: if no_new_privs or nosuid and a 2127 * transition is explicitly requested, then fail the exec. 2128 */ 2129 if (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS) 2130 return -EPERM; 2131 if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) 2132 return -EACCES; 2133 } else { 2134 /* Check for a default transition on this program. */ 2135 rc = security_transition_sid(old_tsec->sid, isec->sid, 2136 SECCLASS_PROCESS, NULL, 2137 &new_tsec->sid); 2138 if (rc) 2139 return rc; 2140 } 2141 2142 ad.type = LSM_AUDIT_DATA_PATH; 2143 ad.u.path = bprm->file->f_path; 2144 2145 if ((bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) || 2146 (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)) 2147 new_tsec->sid = old_tsec->sid; 2148 2149 if (new_tsec->sid == old_tsec->sid) { 2150 rc = avc_has_perm(old_tsec->sid, isec->sid, 2151 SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad); 2152 if (rc) 2153 return rc; 2154 } else { 2155 /* Check permissions for the transition. */ 2156 rc = avc_has_perm(old_tsec->sid, new_tsec->sid, 2157 SECCLASS_PROCESS, PROCESS__TRANSITION, &ad); 2158 if (rc) 2159 return rc; 2160 2161 rc = avc_has_perm(new_tsec->sid, isec->sid, 2162 SECCLASS_FILE, FILE__ENTRYPOINT, &ad); 2163 if (rc) 2164 return rc; 2165 2166 /* Check for shared state */ 2167 if (bprm->unsafe & LSM_UNSAFE_SHARE) { 2168 rc = avc_has_perm(old_tsec->sid, new_tsec->sid, 2169 SECCLASS_PROCESS, PROCESS__SHARE, 2170 NULL); 2171 if (rc) 2172 return -EPERM; 2173 } 2174 2175 /* Make sure that anyone attempting to ptrace over a task that 2176 * changes its SID has the appropriate permit */ 2177 if (bprm->unsafe & 2178 (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) { 2179 struct task_struct *tracer; 2180 struct task_security_struct *sec; 2181 u32 ptsid = 0; 2182 2183 rcu_read_lock(); 2184 tracer = ptrace_parent(current); 2185 if (likely(tracer != NULL)) { 2186 sec = __task_cred(tracer)->security; 2187 ptsid = sec->sid; 2188 } 2189 rcu_read_unlock(); 2190 2191 if (ptsid != 0) { 2192 rc = avc_has_perm(ptsid, new_tsec->sid, 2193 SECCLASS_PROCESS, 2194 PROCESS__PTRACE, NULL); 2195 if (rc) 2196 return -EPERM; 2197 } 2198 } 2199 2200 /* Clear any possibly unsafe personality bits on exec: */ 2201 bprm->per_clear |= PER_CLEAR_ON_SETID; 2202 } 2203 2204 return 0; 2205 } 2206 2207 static int selinux_bprm_secureexec(struct linux_binprm *bprm) 2208 { 2209 const struct task_security_struct *tsec = current_security(); 2210 u32 sid, osid; 2211 int atsecure = 0; 2212 2213 sid = tsec->sid; 2214 osid = tsec->osid; 2215 2216 if (osid != sid) { 2217 /* Enable secure mode for SIDs transitions unless 2218 the noatsecure permission is granted between 2219 the two SIDs, i.e. ahp returns 0. */ 2220 atsecure = avc_has_perm(osid, sid, 2221 SECCLASS_PROCESS, 2222 PROCESS__NOATSECURE, NULL); 2223 } 2224 2225 return (atsecure || cap_bprm_secureexec(bprm)); 2226 } 2227 2228 static int match_file(const void *p, struct file *file, unsigned fd) 2229 { 2230 return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0; 2231 } 2232 2233 /* Derived from fs/exec.c:flush_old_files. */ 2234 static inline void flush_unauthorized_files(const struct cred *cred, 2235 struct files_struct *files) 2236 { 2237 struct file *file, *devnull = NULL; 2238 struct tty_struct *tty; 2239 int drop_tty = 0; 2240 unsigned n; 2241 2242 tty = get_current_tty(); 2243 if (tty) { 2244 spin_lock(&tty_files_lock); 2245 if (!list_empty(&tty->tty_files)) { 2246 struct tty_file_private *file_priv; 2247 2248 /* Revalidate access to controlling tty. 2249 Use file_path_has_perm on the tty path directly 2250 rather than using file_has_perm, as this particular 2251 open file may belong to another process and we are 2252 only interested in the inode-based check here. */ 2253 file_priv = list_first_entry(&tty->tty_files, 2254 struct tty_file_private, list); 2255 file = file_priv->file; 2256 if (file_path_has_perm(cred, file, FILE__READ | FILE__WRITE)) 2257 drop_tty = 1; 2258 } 2259 spin_unlock(&tty_files_lock); 2260 tty_kref_put(tty); 2261 } 2262 /* Reset controlling tty. */ 2263 if (drop_tty) 2264 no_tty(); 2265 2266 /* Revalidate access to inherited open files. */ 2267 n = iterate_fd(files, 0, match_file, cred); 2268 if (!n) /* none found? */ 2269 return; 2270 2271 devnull = dentry_open(&selinux_null, O_RDWR, cred); 2272 if (IS_ERR(devnull)) 2273 devnull = NULL; 2274 /* replace all the matching ones with this */ 2275 do { 2276 replace_fd(n - 1, devnull, 0); 2277 } while ((n = iterate_fd(files, n, match_file, cred)) != 0); 2278 if (devnull) 2279 fput(devnull); 2280 } 2281 2282 /* 2283 * Prepare a process for imminent new credential changes due to exec 2284 */ 2285 static void selinux_bprm_committing_creds(struct linux_binprm *bprm) 2286 { 2287 struct task_security_struct *new_tsec; 2288 struct rlimit *rlim, *initrlim; 2289 int rc, i; 2290 2291 new_tsec = bprm->cred->security; 2292 if (new_tsec->sid == new_tsec->osid) 2293 return; 2294 2295 /* Close files for which the new task SID is not authorized. */ 2296 flush_unauthorized_files(bprm->cred, current->files); 2297 2298 /* Always clear parent death signal on SID transitions. */ 2299 current->pdeath_signal = 0; 2300 2301 /* Check whether the new SID can inherit resource limits from the old 2302 * SID. If not, reset all soft limits to the lower of the current 2303 * task's hard limit and the init task's soft limit. 2304 * 2305 * Note that the setting of hard limits (even to lower them) can be 2306 * controlled by the setrlimit check. The inclusion of the init task's 2307 * soft limit into the computation is to avoid resetting soft limits 2308 * higher than the default soft limit for cases where the default is 2309 * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK. 2310 */ 2311 rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS, 2312 PROCESS__RLIMITINH, NULL); 2313 if (rc) { 2314 /* protect against do_prlimit() */ 2315 task_lock(current); 2316 for (i = 0; i < RLIM_NLIMITS; i++) { 2317 rlim = current->signal->rlim + i; 2318 initrlim = init_task.signal->rlim + i; 2319 rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur); 2320 } 2321 task_unlock(current); 2322 update_rlimit_cpu(current, rlimit(RLIMIT_CPU)); 2323 } 2324 } 2325 2326 /* 2327 * Clean up the process immediately after the installation of new credentials 2328 * due to exec 2329 */ 2330 static void selinux_bprm_committed_creds(struct linux_binprm *bprm) 2331 { 2332 const struct task_security_struct *tsec = current_security(); 2333 struct itimerval itimer; 2334 u32 osid, sid; 2335 int rc, i; 2336 2337 osid = tsec->osid; 2338 sid = tsec->sid; 2339 2340 if (sid == osid) 2341 return; 2342 2343 /* Check whether the new SID can inherit signal state from the old SID. 2344 * If not, clear itimers to avoid subsequent signal generation and 2345 * flush and unblock signals. 2346 * 2347 * This must occur _after_ the task SID has been updated so that any 2348 * kill done after the flush will be checked against the new SID. 2349 */ 2350 rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL); 2351 if (rc) { 2352 memset(&itimer, 0, sizeof itimer); 2353 for (i = 0; i < 3; i++) 2354 do_setitimer(i, &itimer, NULL); 2355 spin_lock_irq(¤t->sighand->siglock); 2356 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) { 2357 __flush_signals(current); 2358 flush_signal_handlers(current, 1); 2359 sigemptyset(¤t->blocked); 2360 } 2361 spin_unlock_irq(¤t->sighand->siglock); 2362 } 2363 2364 /* Wake up the parent if it is waiting so that it can recheck 2365 * wait permission to the new task SID. */ 2366 read_lock(&tasklist_lock); 2367 __wake_up_parent(current, current->real_parent); 2368 read_unlock(&tasklist_lock); 2369 } 2370 2371 /* superblock security operations */ 2372 2373 static int selinux_sb_alloc_security(struct super_block *sb) 2374 { 2375 return superblock_alloc_security(sb); 2376 } 2377 2378 static void selinux_sb_free_security(struct super_block *sb) 2379 { 2380 superblock_free_security(sb); 2381 } 2382 2383 static inline int match_prefix(char *prefix, int plen, char *option, int olen) 2384 { 2385 if (plen > olen) 2386 return 0; 2387 2388 return !memcmp(prefix, option, plen); 2389 } 2390 2391 static inline int selinux_option(char *option, int len) 2392 { 2393 return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) || 2394 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) || 2395 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) || 2396 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) || 2397 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len)); 2398 } 2399 2400 static inline void take_option(char **to, char *from, int *first, int len) 2401 { 2402 if (!*first) { 2403 **to = ','; 2404 *to += 1; 2405 } else 2406 *first = 0; 2407 memcpy(*to, from, len); 2408 *to += len; 2409 } 2410 2411 static inline void take_selinux_option(char **to, char *from, int *first, 2412 int len) 2413 { 2414 int current_size = 0; 2415 2416 if (!*first) { 2417 **to = '|'; 2418 *to += 1; 2419 } else 2420 *first = 0; 2421 2422 while (current_size < len) { 2423 if (*from != '"') { 2424 **to = *from; 2425 *to += 1; 2426 } 2427 from += 1; 2428 current_size += 1; 2429 } 2430 } 2431 2432 static int selinux_sb_copy_data(char *orig, char *copy) 2433 { 2434 int fnosec, fsec, rc = 0; 2435 char *in_save, *in_curr, *in_end; 2436 char *sec_curr, *nosec_save, *nosec; 2437 int open_quote = 0; 2438 2439 in_curr = orig; 2440 sec_curr = copy; 2441 2442 nosec = (char *)get_zeroed_page(GFP_KERNEL); 2443 if (!nosec) { 2444 rc = -ENOMEM; 2445 goto out; 2446 } 2447 2448 nosec_save = nosec; 2449 fnosec = fsec = 1; 2450 in_save = in_end = orig; 2451 2452 do { 2453 if (*in_end == '"') 2454 open_quote = !open_quote; 2455 if ((*in_end == ',' && open_quote == 0) || 2456 *in_end == '\0') { 2457 int len = in_end - in_curr; 2458 2459 if (selinux_option(in_curr, len)) 2460 take_selinux_option(&sec_curr, in_curr, &fsec, len); 2461 else 2462 take_option(&nosec, in_curr, &fnosec, len); 2463 2464 in_curr = in_end + 1; 2465 } 2466 } while (*in_end++); 2467 2468 strcpy(in_save, nosec_save); 2469 free_page((unsigned long)nosec_save); 2470 out: 2471 return rc; 2472 } 2473 2474 static int selinux_sb_remount(struct super_block *sb, void *data) 2475 { 2476 int rc, i, *flags; 2477 struct security_mnt_opts opts; 2478 char *secdata, **mount_options; 2479 struct superblock_security_struct *sbsec = sb->s_security; 2480 2481 if (!(sbsec->flags & SE_SBINITIALIZED)) 2482 return 0; 2483 2484 if (!data) 2485 return 0; 2486 2487 if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) 2488 return 0; 2489 2490 security_init_mnt_opts(&opts); 2491 secdata = alloc_secdata(); 2492 if (!secdata) 2493 return -ENOMEM; 2494 rc = selinux_sb_copy_data(data, secdata); 2495 if (rc) 2496 goto out_free_secdata; 2497 2498 rc = selinux_parse_opts_str(secdata, &opts); 2499 if (rc) 2500 goto out_free_secdata; 2501 2502 mount_options = opts.mnt_opts; 2503 flags = opts.mnt_opts_flags; 2504 2505 for (i = 0; i < opts.num_mnt_opts; i++) { 2506 u32 sid; 2507 size_t len; 2508 2509 if (flags[i] == SBLABEL_MNT) 2510 continue; 2511 len = strlen(mount_options[i]); 2512 rc = security_context_to_sid(mount_options[i], len, &sid, 2513 GFP_KERNEL); 2514 if (rc) { 2515 printk(KERN_WARNING "SELinux: security_context_to_sid" 2516 "(%s) failed for (dev %s, type %s) errno=%d\n", 2517 mount_options[i], sb->s_id, sb->s_type->name, rc); 2518 goto out_free_opts; 2519 } 2520 rc = -EINVAL; 2521 switch (flags[i]) { 2522 case FSCONTEXT_MNT: 2523 if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid)) 2524 goto out_bad_option; 2525 break; 2526 case CONTEXT_MNT: 2527 if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid)) 2528 goto out_bad_option; 2529 break; 2530 case ROOTCONTEXT_MNT: { 2531 struct inode_security_struct *root_isec; 2532 root_isec = sb->s_root->d_inode->i_security; 2533 2534 if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid)) 2535 goto out_bad_option; 2536 break; 2537 } 2538 case DEFCONTEXT_MNT: 2539 if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid)) 2540 goto out_bad_option; 2541 break; 2542 default: 2543 goto out_free_opts; 2544 } 2545 } 2546 2547 rc = 0; 2548 out_free_opts: 2549 security_free_mnt_opts(&opts); 2550 out_free_secdata: 2551 free_secdata(secdata); 2552 return rc; 2553 out_bad_option: 2554 printk(KERN_WARNING "SELinux: unable to change security options " 2555 "during remount (dev %s, type=%s)\n", sb->s_id, 2556 sb->s_type->name); 2557 goto out_free_opts; 2558 } 2559 2560 static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data) 2561 { 2562 const struct cred *cred = current_cred(); 2563 struct common_audit_data ad; 2564 int rc; 2565 2566 rc = superblock_doinit(sb, data); 2567 if (rc) 2568 return rc; 2569 2570 /* Allow all mounts performed by the kernel */ 2571 if (flags & MS_KERNMOUNT) 2572 return 0; 2573 2574 ad.type = LSM_AUDIT_DATA_DENTRY; 2575 ad.u.dentry = sb->s_root; 2576 return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad); 2577 } 2578 2579 static int selinux_sb_statfs(struct dentry *dentry) 2580 { 2581 const struct cred *cred = current_cred(); 2582 struct common_audit_data ad; 2583 2584 ad.type = LSM_AUDIT_DATA_DENTRY; 2585 ad.u.dentry = dentry->d_sb->s_root; 2586 return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad); 2587 } 2588 2589 static int selinux_mount(const char *dev_name, 2590 struct path *path, 2591 const char *type, 2592 unsigned long flags, 2593 void *data) 2594 { 2595 const struct cred *cred = current_cred(); 2596 2597 if (flags & MS_REMOUNT) 2598 return superblock_has_perm(cred, path->dentry->d_sb, 2599 FILESYSTEM__REMOUNT, NULL); 2600 else 2601 return path_has_perm(cred, path, FILE__MOUNTON); 2602 } 2603 2604 static int selinux_umount(struct vfsmount *mnt, int flags) 2605 { 2606 const struct cred *cred = current_cred(); 2607 2608 return superblock_has_perm(cred, mnt->mnt_sb, 2609 FILESYSTEM__UNMOUNT, NULL); 2610 } 2611 2612 /* inode security operations */ 2613 2614 static int selinux_inode_alloc_security(struct inode *inode) 2615 { 2616 return inode_alloc_security(inode); 2617 } 2618 2619 static void selinux_inode_free_security(struct inode *inode) 2620 { 2621 inode_free_security(inode); 2622 } 2623 2624 static int selinux_dentry_init_security(struct dentry *dentry, int mode, 2625 struct qstr *name, void **ctx, 2626 u32 *ctxlen) 2627 { 2628 const struct cred *cred = current_cred(); 2629 struct task_security_struct *tsec; 2630 struct inode_security_struct *dsec; 2631 struct superblock_security_struct *sbsec; 2632 struct inode *dir = dentry->d_parent->d_inode; 2633 u32 newsid; 2634 int rc; 2635 2636 tsec = cred->security; 2637 dsec = dir->i_security; 2638 sbsec = dir->i_sb->s_security; 2639 2640 if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) { 2641 newsid = tsec->create_sid; 2642 } else { 2643 rc = security_transition_sid(tsec->sid, dsec->sid, 2644 inode_mode_to_security_class(mode), 2645 name, 2646 &newsid); 2647 if (rc) { 2648 printk(KERN_WARNING 2649 "%s: security_transition_sid failed, rc=%d\n", 2650 __func__, -rc); 2651 return rc; 2652 } 2653 } 2654 2655 return security_sid_to_context(newsid, (char **)ctx, ctxlen); 2656 } 2657 2658 static int selinux_inode_init_security(struct inode *inode, struct inode *dir, 2659 const struct qstr *qstr, 2660 const char **name, 2661 void **value, size_t *len) 2662 { 2663 const struct task_security_struct *tsec = current_security(); 2664 struct inode_security_struct *dsec; 2665 struct superblock_security_struct *sbsec; 2666 u32 sid, newsid, clen; 2667 int rc; 2668 char *context; 2669 2670 dsec = dir->i_security; 2671 sbsec = dir->i_sb->s_security; 2672 2673 sid = tsec->sid; 2674 newsid = tsec->create_sid; 2675 2676 if ((sbsec->flags & SE_SBINITIALIZED) && 2677 (sbsec->behavior == SECURITY_FS_USE_MNTPOINT)) 2678 newsid = sbsec->mntpoint_sid; 2679 else if (!newsid || !(sbsec->flags & SBLABEL_MNT)) { 2680 rc = security_transition_sid(sid, dsec->sid, 2681 inode_mode_to_security_class(inode->i_mode), 2682 qstr, &newsid); 2683 if (rc) { 2684 printk(KERN_WARNING "%s: " 2685 "security_transition_sid failed, rc=%d (dev=%s " 2686 "ino=%ld)\n", 2687 __func__, 2688 -rc, inode->i_sb->s_id, inode->i_ino); 2689 return rc; 2690 } 2691 } 2692 2693 /* Possibly defer initialization to selinux_complete_init. */ 2694 if (sbsec->flags & SE_SBINITIALIZED) { 2695 struct inode_security_struct *isec = inode->i_security; 2696 isec->sclass = inode_mode_to_security_class(inode->i_mode); 2697 isec->sid = newsid; 2698 isec->initialized = 1; 2699 } 2700 2701 if (!ss_initialized || !(sbsec->flags & SBLABEL_MNT)) 2702 return -EOPNOTSUPP; 2703 2704 if (name) 2705 *name = XATTR_SELINUX_SUFFIX; 2706 2707 if (value && len) { 2708 rc = security_sid_to_context_force(newsid, &context, &clen); 2709 if (rc) 2710 return rc; 2711 *value = context; 2712 *len = clen; 2713 } 2714 2715 return 0; 2716 } 2717 2718 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode) 2719 { 2720 return may_create(dir, dentry, SECCLASS_FILE); 2721 } 2722 2723 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry) 2724 { 2725 return may_link(dir, old_dentry, MAY_LINK); 2726 } 2727 2728 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry) 2729 { 2730 return may_link(dir, dentry, MAY_UNLINK); 2731 } 2732 2733 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name) 2734 { 2735 return may_create(dir, dentry, SECCLASS_LNK_FILE); 2736 } 2737 2738 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask) 2739 { 2740 return may_create(dir, dentry, SECCLASS_DIR); 2741 } 2742 2743 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry) 2744 { 2745 return may_link(dir, dentry, MAY_RMDIR); 2746 } 2747 2748 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) 2749 { 2750 return may_create(dir, dentry, inode_mode_to_security_class(mode)); 2751 } 2752 2753 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry, 2754 struct inode *new_inode, struct dentry *new_dentry) 2755 { 2756 return may_rename(old_inode, old_dentry, new_inode, new_dentry); 2757 } 2758 2759 static int selinux_inode_readlink(struct dentry *dentry) 2760 { 2761 const struct cred *cred = current_cred(); 2762 2763 return dentry_has_perm(cred, dentry, FILE__READ); 2764 } 2765 2766 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata) 2767 { 2768 const struct cred *cred = current_cred(); 2769 2770 return dentry_has_perm(cred, dentry, FILE__READ); 2771 } 2772 2773 static noinline int audit_inode_permission(struct inode *inode, 2774 u32 perms, u32 audited, u32 denied, 2775 int result, 2776 unsigned flags) 2777 { 2778 struct common_audit_data ad; 2779 struct inode_security_struct *isec = inode->i_security; 2780 int rc; 2781 2782 ad.type = LSM_AUDIT_DATA_INODE; 2783 ad.u.inode = inode; 2784 2785 rc = slow_avc_audit(current_sid(), isec->sid, isec->sclass, perms, 2786 audited, denied, result, &ad, flags); 2787 if (rc) 2788 return rc; 2789 return 0; 2790 } 2791 2792 static int selinux_inode_permission(struct inode *inode, int mask) 2793 { 2794 const struct cred *cred = current_cred(); 2795 u32 perms; 2796 bool from_access; 2797 unsigned flags = mask & MAY_NOT_BLOCK; 2798 struct inode_security_struct *isec; 2799 u32 sid; 2800 struct av_decision avd; 2801 int rc, rc2; 2802 u32 audited, denied; 2803 2804 from_access = mask & MAY_ACCESS; 2805 mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND); 2806 2807 /* No permission to check. Existence test. */ 2808 if (!mask) 2809 return 0; 2810 2811 validate_creds(cred); 2812 2813 if (unlikely(IS_PRIVATE(inode))) 2814 return 0; 2815 2816 perms = file_mask_to_av(inode->i_mode, mask); 2817 2818 sid = cred_sid(cred); 2819 isec = inode->i_security; 2820 2821 rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd); 2822 audited = avc_audit_required(perms, &avd, rc, 2823 from_access ? FILE__AUDIT_ACCESS : 0, 2824 &denied); 2825 if (likely(!audited)) 2826 return rc; 2827 2828 rc2 = audit_inode_permission(inode, perms, audited, denied, rc, flags); 2829 if (rc2) 2830 return rc2; 2831 return rc; 2832 } 2833 2834 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr) 2835 { 2836 const struct cred *cred = current_cred(); 2837 unsigned int ia_valid = iattr->ia_valid; 2838 __u32 av = FILE__WRITE; 2839 2840 /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */ 2841 if (ia_valid & ATTR_FORCE) { 2842 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE | 2843 ATTR_FORCE); 2844 if (!ia_valid) 2845 return 0; 2846 } 2847 2848 if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | 2849 ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET)) 2850 return dentry_has_perm(cred, dentry, FILE__SETATTR); 2851 2852 if (selinux_policycap_openperm && (ia_valid & ATTR_SIZE)) 2853 av |= FILE__OPEN; 2854 2855 return dentry_has_perm(cred, dentry, av); 2856 } 2857 2858 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) 2859 { 2860 const struct cred *cred = current_cred(); 2861 struct path path; 2862 2863 path.dentry = dentry; 2864 path.mnt = mnt; 2865 2866 return path_has_perm(cred, &path, FILE__GETATTR); 2867 } 2868 2869 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name) 2870 { 2871 const struct cred *cred = current_cred(); 2872 2873 if (!strncmp(name, XATTR_SECURITY_PREFIX, 2874 sizeof XATTR_SECURITY_PREFIX - 1)) { 2875 if (!strcmp(name, XATTR_NAME_CAPS)) { 2876 if (!capable(CAP_SETFCAP)) 2877 return -EPERM; 2878 } else if (!capable(CAP_SYS_ADMIN)) { 2879 /* A different attribute in the security namespace. 2880 Restrict to administrator. */ 2881 return -EPERM; 2882 } 2883 } 2884 2885 /* Not an attribute we recognize, so just check the 2886 ordinary setattr permission. */ 2887 return dentry_has_perm(cred, dentry, FILE__SETATTR); 2888 } 2889 2890 static int selinux_inode_setxattr(struct dentry *dentry, const char *name, 2891 const void *value, size_t size, int flags) 2892 { 2893 struct inode *inode = dentry->d_inode; 2894 struct inode_security_struct *isec = inode->i_security; 2895 struct superblock_security_struct *sbsec; 2896 struct common_audit_data ad; 2897 u32 newsid, sid = current_sid(); 2898 int rc = 0; 2899 2900 if (strcmp(name, XATTR_NAME_SELINUX)) 2901 return selinux_inode_setotherxattr(dentry, name); 2902 2903 sbsec = inode->i_sb->s_security; 2904 if (!(sbsec->flags & SBLABEL_MNT)) 2905 return -EOPNOTSUPP; 2906 2907 if (!inode_owner_or_capable(inode)) 2908 return -EPERM; 2909 2910 ad.type = LSM_AUDIT_DATA_DENTRY; 2911 ad.u.dentry = dentry; 2912 2913 rc = avc_has_perm(sid, isec->sid, isec->sclass, 2914 FILE__RELABELFROM, &ad); 2915 if (rc) 2916 return rc; 2917 2918 rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL); 2919 if (rc == -EINVAL) { 2920 if (!capable(CAP_MAC_ADMIN)) { 2921 struct audit_buffer *ab; 2922 size_t audit_size; 2923 const char *str; 2924 2925 /* We strip a nul only if it is at the end, otherwise the 2926 * context contains a nul and we should audit that */ 2927 if (value) { 2928 str = value; 2929 if (str[size - 1] == '\0') 2930 audit_size = size - 1; 2931 else 2932 audit_size = size; 2933 } else { 2934 str = ""; 2935 audit_size = 0; 2936 } 2937 ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR); 2938 audit_log_format(ab, "op=setxattr invalid_context="); 2939 audit_log_n_untrustedstring(ab, value, audit_size); 2940 audit_log_end(ab); 2941 2942 return rc; 2943 } 2944 rc = security_context_to_sid_force(value, size, &newsid); 2945 } 2946 if (rc) 2947 return rc; 2948 2949 rc = avc_has_perm(sid, newsid, isec->sclass, 2950 FILE__RELABELTO, &ad); 2951 if (rc) 2952 return rc; 2953 2954 rc = security_validate_transition(isec->sid, newsid, sid, 2955 isec->sclass); 2956 if (rc) 2957 return rc; 2958 2959 return avc_has_perm(newsid, 2960 sbsec->sid, 2961 SECCLASS_FILESYSTEM, 2962 FILESYSTEM__ASSOCIATE, 2963 &ad); 2964 } 2965 2966 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name, 2967 const void *value, size_t size, 2968 int flags) 2969 { 2970 struct inode *inode = dentry->d_inode; 2971 struct inode_security_struct *isec = inode->i_security; 2972 u32 newsid; 2973 int rc; 2974 2975 if (strcmp(name, XATTR_NAME_SELINUX)) { 2976 /* Not an attribute we recognize, so nothing to do. */ 2977 return; 2978 } 2979 2980 rc = security_context_to_sid_force(value, size, &newsid); 2981 if (rc) { 2982 printk(KERN_ERR "SELinux: unable to map context to SID" 2983 "for (%s, %lu), rc=%d\n", 2984 inode->i_sb->s_id, inode->i_ino, -rc); 2985 return; 2986 } 2987 2988 isec->sclass = inode_mode_to_security_class(inode->i_mode); 2989 isec->sid = newsid; 2990 isec->initialized = 1; 2991 2992 return; 2993 } 2994 2995 static int selinux_inode_getxattr(struct dentry *dentry, const char *name) 2996 { 2997 const struct cred *cred = current_cred(); 2998 2999 return dentry_has_perm(cred, dentry, FILE__GETATTR); 3000 } 3001 3002 static int selinux_inode_listxattr(struct dentry *dentry) 3003 { 3004 const struct cred *cred = current_cred(); 3005 3006 return dentry_has_perm(cred, dentry, FILE__GETATTR); 3007 } 3008 3009 static int selinux_inode_removexattr(struct dentry *dentry, const char *name) 3010 { 3011 if (strcmp(name, XATTR_NAME_SELINUX)) 3012 return selinux_inode_setotherxattr(dentry, name); 3013 3014 /* No one is allowed to remove a SELinux security label. 3015 You can change the label, but all data must be labeled. */ 3016 return -EACCES; 3017 } 3018 3019 /* 3020 * Copy the inode security context value to the user. 3021 * 3022 * Permission check is handled by selinux_inode_getxattr hook. 3023 */ 3024 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc) 3025 { 3026 u32 size; 3027 int error; 3028 char *context = NULL; 3029 struct inode_security_struct *isec = inode->i_security; 3030 3031 if (strcmp(name, XATTR_SELINUX_SUFFIX)) 3032 return -EOPNOTSUPP; 3033 3034 /* 3035 * If the caller has CAP_MAC_ADMIN, then get the raw context 3036 * value even if it is not defined by current policy; otherwise, 3037 * use the in-core value under current policy. 3038 * Use the non-auditing forms of the permission checks since 3039 * getxattr may be called by unprivileged processes commonly 3040 * and lack of permission just means that we fall back to the 3041 * in-core context value, not a denial. 3042 */ 3043 error = selinux_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN, 3044 SECURITY_CAP_NOAUDIT); 3045 if (!error) 3046 error = security_sid_to_context_force(isec->sid, &context, 3047 &size); 3048 else 3049 error = security_sid_to_context(isec->sid, &context, &size); 3050 if (error) 3051 return error; 3052 error = size; 3053 if (alloc) { 3054 *buffer = context; 3055 goto out_nofree; 3056 } 3057 kfree(context); 3058 out_nofree: 3059 return error; 3060 } 3061 3062 static int selinux_inode_setsecurity(struct inode *inode, const char *name, 3063 const void *value, size_t size, int flags) 3064 { 3065 struct inode_security_struct *isec = inode->i_security; 3066 u32 newsid; 3067 int rc; 3068 3069 if (strcmp(name, XATTR_SELINUX_SUFFIX)) 3070 return -EOPNOTSUPP; 3071 3072 if (!value || !size) 3073 return -EACCES; 3074 3075 rc = security_context_to_sid((void *)value, size, &newsid, GFP_KERNEL); 3076 if (rc) 3077 return rc; 3078 3079 isec->sclass = inode_mode_to_security_class(inode->i_mode); 3080 isec->sid = newsid; 3081 isec->initialized = 1; 3082 return 0; 3083 } 3084 3085 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) 3086 { 3087 const int len = sizeof(XATTR_NAME_SELINUX); 3088 if (buffer && len <= buffer_size) 3089 memcpy(buffer, XATTR_NAME_SELINUX, len); 3090 return len; 3091 } 3092 3093 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid) 3094 { 3095 struct inode_security_struct *isec = inode->i_security; 3096 *secid = isec->sid; 3097 } 3098 3099 /* file security operations */ 3100 3101 static int selinux_revalidate_file_permission(struct file *file, int mask) 3102 { 3103 const struct cred *cred = current_cred(); 3104 struct inode *inode = file_inode(file); 3105 3106 /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */ 3107 if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE)) 3108 mask |= MAY_APPEND; 3109 3110 return file_has_perm(cred, file, 3111 file_mask_to_av(inode->i_mode, mask)); 3112 } 3113 3114 static int selinux_file_permission(struct file *file, int mask) 3115 { 3116 struct inode *inode = file_inode(file); 3117 struct file_security_struct *fsec = file->f_security; 3118 struct inode_security_struct *isec = inode->i_security; 3119 u32 sid = current_sid(); 3120 3121 if (!mask) 3122 /* No permission to check. Existence test. */ 3123 return 0; 3124 3125 if (sid == fsec->sid && fsec->isid == isec->sid && 3126 fsec->pseqno == avc_policy_seqno()) 3127 /* No change since file_open check. */ 3128 return 0; 3129 3130 return selinux_revalidate_file_permission(file, mask); 3131 } 3132 3133 static int selinux_file_alloc_security(struct file *file) 3134 { 3135 return file_alloc_security(file); 3136 } 3137 3138 static void selinux_file_free_security(struct file *file) 3139 { 3140 file_free_security(file); 3141 } 3142 3143 static int selinux_file_ioctl(struct file *file, unsigned int cmd, 3144 unsigned long arg) 3145 { 3146 const struct cred *cred = current_cred(); 3147 int error = 0; 3148 3149 switch (cmd) { 3150 case FIONREAD: 3151 /* fall through */ 3152 case FIBMAP: 3153 /* fall through */ 3154 case FIGETBSZ: 3155 /* fall through */ 3156 case FS_IOC_GETFLAGS: 3157 /* fall through */ 3158 case FS_IOC_GETVERSION: 3159 error = file_has_perm(cred, file, FILE__GETATTR); 3160 break; 3161 3162 case FS_IOC_SETFLAGS: 3163 /* fall through */ 3164 case FS_IOC_SETVERSION: 3165 error = file_has_perm(cred, file, FILE__SETATTR); 3166 break; 3167 3168 /* sys_ioctl() checks */ 3169 case FIONBIO: 3170 /* fall through */ 3171 case FIOASYNC: 3172 error = file_has_perm(cred, file, 0); 3173 break; 3174 3175 case KDSKBENT: 3176 case KDSKBSENT: 3177 error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG, 3178 SECURITY_CAP_AUDIT); 3179 break; 3180 3181 /* default case assumes that the command will go 3182 * to the file's ioctl() function. 3183 */ 3184 default: 3185 error = file_has_perm(cred, file, FILE__IOCTL); 3186 } 3187 return error; 3188 } 3189 3190 static int default_noexec; 3191 3192 static int file_map_prot_check(struct file *file, unsigned long prot, int shared) 3193 { 3194 const struct cred *cred = current_cred(); 3195 int rc = 0; 3196 3197 if (default_noexec && 3198 (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) { 3199 /* 3200 * We are making executable an anonymous mapping or a 3201 * private file mapping that will also be writable. 3202 * This has an additional check. 3203 */ 3204 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM); 3205 if (rc) 3206 goto error; 3207 } 3208 3209 if (file) { 3210 /* read access is always possible with a mapping */ 3211 u32 av = FILE__READ; 3212 3213 /* write access only matters if the mapping is shared */ 3214 if (shared && (prot & PROT_WRITE)) 3215 av |= FILE__WRITE; 3216 3217 if (prot & PROT_EXEC) 3218 av |= FILE__EXECUTE; 3219 3220 return file_has_perm(cred, file, av); 3221 } 3222 3223 error: 3224 return rc; 3225 } 3226 3227 static int selinux_mmap_addr(unsigned long addr) 3228 { 3229 int rc; 3230 3231 /* do DAC check on address space usage */ 3232 rc = cap_mmap_addr(addr); 3233 if (rc) 3234 return rc; 3235 3236 if (addr < CONFIG_LSM_MMAP_MIN_ADDR) { 3237 u32 sid = current_sid(); 3238 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT, 3239 MEMPROTECT__MMAP_ZERO, NULL); 3240 } 3241 3242 return rc; 3243 } 3244 3245 static int selinux_mmap_file(struct file *file, unsigned long reqprot, 3246 unsigned long prot, unsigned long flags) 3247 { 3248 if (selinux_checkreqprot) 3249 prot = reqprot; 3250 3251 return file_map_prot_check(file, prot, 3252 (flags & MAP_TYPE) == MAP_SHARED); 3253 } 3254 3255 static int selinux_file_mprotect(struct vm_area_struct *vma, 3256 unsigned long reqprot, 3257 unsigned long prot) 3258 { 3259 const struct cred *cred = current_cred(); 3260 3261 if (selinux_checkreqprot) 3262 prot = reqprot; 3263 3264 if (default_noexec && 3265 (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) { 3266 int rc = 0; 3267 if (vma->vm_start >= vma->vm_mm->start_brk && 3268 vma->vm_end <= vma->vm_mm->brk) { 3269 rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP); 3270 } else if (!vma->vm_file && 3271 vma->vm_start <= vma->vm_mm->start_stack && 3272 vma->vm_end >= vma->vm_mm->start_stack) { 3273 rc = current_has_perm(current, PROCESS__EXECSTACK); 3274 } else if (vma->vm_file && vma->anon_vma) { 3275 /* 3276 * We are making executable a file mapping that has 3277 * had some COW done. Since pages might have been 3278 * written, check ability to execute the possibly 3279 * modified content. This typically should only 3280 * occur for text relocations. 3281 */ 3282 rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD); 3283 } 3284 if (rc) 3285 return rc; 3286 } 3287 3288 return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED); 3289 } 3290 3291 static int selinux_file_lock(struct file *file, unsigned int cmd) 3292 { 3293 const struct cred *cred = current_cred(); 3294 3295 return file_has_perm(cred, file, FILE__LOCK); 3296 } 3297 3298 static int selinux_file_fcntl(struct file *file, unsigned int cmd, 3299 unsigned long arg) 3300 { 3301 const struct cred *cred = current_cred(); 3302 int err = 0; 3303 3304 switch (cmd) { 3305 case F_SETFL: 3306 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) { 3307 err = file_has_perm(cred, file, FILE__WRITE); 3308 break; 3309 } 3310 /* fall through */ 3311 case F_SETOWN: 3312 case F_SETSIG: 3313 case F_GETFL: 3314 case F_GETOWN: 3315 case F_GETSIG: 3316 case F_GETOWNER_UIDS: 3317 /* Just check FD__USE permission */ 3318 err = file_has_perm(cred, file, 0); 3319 break; 3320 case F_GETLK: 3321 case F_SETLK: 3322 case F_SETLKW: 3323 case F_OFD_GETLK: 3324 case F_OFD_SETLK: 3325 case F_OFD_SETLKW: 3326 #if BITS_PER_LONG == 32 3327 case F_GETLK64: 3328 case F_SETLK64: 3329 case F_SETLKW64: 3330 #endif 3331 err = file_has_perm(cred, file, FILE__LOCK); 3332 break; 3333 } 3334 3335 return err; 3336 } 3337 3338 static int selinux_file_set_fowner(struct file *file) 3339 { 3340 struct file_security_struct *fsec; 3341 3342 fsec = file->f_security; 3343 fsec->fown_sid = current_sid(); 3344 3345 return 0; 3346 } 3347 3348 static int selinux_file_send_sigiotask(struct task_struct *tsk, 3349 struct fown_struct *fown, int signum) 3350 { 3351 struct file *file; 3352 u32 sid = task_sid(tsk); 3353 u32 perm; 3354 struct file_security_struct *fsec; 3355 3356 /* struct fown_struct is never outside the context of a struct file */ 3357 file = container_of(fown, struct file, f_owner); 3358 3359 fsec = file->f_security; 3360 3361 if (!signum) 3362 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */ 3363 else 3364 perm = signal_to_av(signum); 3365 3366 return avc_has_perm(fsec->fown_sid, sid, 3367 SECCLASS_PROCESS, perm, NULL); 3368 } 3369 3370 static int selinux_file_receive(struct file *file) 3371 { 3372 const struct cred *cred = current_cred(); 3373 3374 return file_has_perm(cred, file, file_to_av(file)); 3375 } 3376 3377 static int selinux_file_open(struct file *file, const struct cred *cred) 3378 { 3379 struct file_security_struct *fsec; 3380 struct inode_security_struct *isec; 3381 3382 fsec = file->f_security; 3383 isec = file_inode(file)->i_security; 3384 /* 3385 * Save inode label and policy sequence number 3386 * at open-time so that selinux_file_permission 3387 * can determine whether revalidation is necessary. 3388 * Task label is already saved in the file security 3389 * struct as its SID. 3390 */ 3391 fsec->isid = isec->sid; 3392 fsec->pseqno = avc_policy_seqno(); 3393 /* 3394 * Since the inode label or policy seqno may have changed 3395 * between the selinux_inode_permission check and the saving 3396 * of state above, recheck that access is still permitted. 3397 * Otherwise, access might never be revalidated against the 3398 * new inode label or new policy. 3399 * This check is not redundant - do not remove. 3400 */ 3401 return file_path_has_perm(cred, file, open_file_to_av(file)); 3402 } 3403 3404 /* task security operations */ 3405 3406 static int selinux_task_create(unsigned long clone_flags) 3407 { 3408 return current_has_perm(current, PROCESS__FORK); 3409 } 3410 3411 /* 3412 * allocate the SELinux part of blank credentials 3413 */ 3414 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp) 3415 { 3416 struct task_security_struct *tsec; 3417 3418 tsec = kzalloc(sizeof(struct task_security_struct), gfp); 3419 if (!tsec) 3420 return -ENOMEM; 3421 3422 cred->security = tsec; 3423 return 0; 3424 } 3425 3426 /* 3427 * detach and free the LSM part of a set of credentials 3428 */ 3429 static void selinux_cred_free(struct cred *cred) 3430 { 3431 struct task_security_struct *tsec = cred->security; 3432 3433 /* 3434 * cred->security == NULL if security_cred_alloc_blank() or 3435 * security_prepare_creds() returned an error. 3436 */ 3437 BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE); 3438 cred->security = (void *) 0x7UL; 3439 kfree(tsec); 3440 } 3441 3442 /* 3443 * prepare a new set of credentials for modification 3444 */ 3445 static int selinux_cred_prepare(struct cred *new, const struct cred *old, 3446 gfp_t gfp) 3447 { 3448 const struct task_security_struct *old_tsec; 3449 struct task_security_struct *tsec; 3450 3451 old_tsec = old->security; 3452 3453 tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp); 3454 if (!tsec) 3455 return -ENOMEM; 3456 3457 new->security = tsec; 3458 return 0; 3459 } 3460 3461 /* 3462 * transfer the SELinux data to a blank set of creds 3463 */ 3464 static void selinux_cred_transfer(struct cred *new, const struct cred *old) 3465 { 3466 const struct task_security_struct *old_tsec = old->security; 3467 struct task_security_struct *tsec = new->security; 3468 3469 *tsec = *old_tsec; 3470 } 3471 3472 /* 3473 * set the security data for a kernel service 3474 * - all the creation contexts are set to unlabelled 3475 */ 3476 static int selinux_kernel_act_as(struct cred *new, u32 secid) 3477 { 3478 struct task_security_struct *tsec = new->security; 3479 u32 sid = current_sid(); 3480 int ret; 3481 3482 ret = avc_has_perm(sid, secid, 3483 SECCLASS_KERNEL_SERVICE, 3484 KERNEL_SERVICE__USE_AS_OVERRIDE, 3485 NULL); 3486 if (ret == 0) { 3487 tsec->sid = secid; 3488 tsec->create_sid = 0; 3489 tsec->keycreate_sid = 0; 3490 tsec->sockcreate_sid = 0; 3491 } 3492 return ret; 3493 } 3494 3495 /* 3496 * set the file creation context in a security record to the same as the 3497 * objective context of the specified inode 3498 */ 3499 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode) 3500 { 3501 struct inode_security_struct *isec = inode->i_security; 3502 struct task_security_struct *tsec = new->security; 3503 u32 sid = current_sid(); 3504 int ret; 3505 3506 ret = avc_has_perm(sid, isec->sid, 3507 SECCLASS_KERNEL_SERVICE, 3508 KERNEL_SERVICE__CREATE_FILES_AS, 3509 NULL); 3510 3511 if (ret == 0) 3512 tsec->create_sid = isec->sid; 3513 return ret; 3514 } 3515 3516 static int selinux_kernel_module_request(char *kmod_name) 3517 { 3518 u32 sid; 3519 struct common_audit_data ad; 3520 3521 sid = task_sid(current); 3522 3523 ad.type = LSM_AUDIT_DATA_KMOD; 3524 ad.u.kmod_name = kmod_name; 3525 3526 return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM, 3527 SYSTEM__MODULE_REQUEST, &ad); 3528 } 3529 3530 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid) 3531 { 3532 return current_has_perm(p, PROCESS__SETPGID); 3533 } 3534 3535 static int selinux_task_getpgid(struct task_struct *p) 3536 { 3537 return current_has_perm(p, PROCESS__GETPGID); 3538 } 3539 3540 static int selinux_task_getsid(struct task_struct *p) 3541 { 3542 return current_has_perm(p, PROCESS__GETSESSION); 3543 } 3544 3545 static void selinux_task_getsecid(struct task_struct *p, u32 *secid) 3546 { 3547 *secid = task_sid(p); 3548 } 3549 3550 static int selinux_task_setnice(struct task_struct *p, int nice) 3551 { 3552 int rc; 3553 3554 rc = cap_task_setnice(p, nice); 3555 if (rc) 3556 return rc; 3557 3558 return current_has_perm(p, PROCESS__SETSCHED); 3559 } 3560 3561 static int selinux_task_setioprio(struct task_struct *p, int ioprio) 3562 { 3563 int rc; 3564 3565 rc = cap_task_setioprio(p, ioprio); 3566 if (rc) 3567 return rc; 3568 3569 return current_has_perm(p, PROCESS__SETSCHED); 3570 } 3571 3572 static int selinux_task_getioprio(struct task_struct *p) 3573 { 3574 return current_has_perm(p, PROCESS__GETSCHED); 3575 } 3576 3577 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource, 3578 struct rlimit *new_rlim) 3579 { 3580 struct rlimit *old_rlim = p->signal->rlim + resource; 3581 3582 /* Control the ability to change the hard limit (whether 3583 lowering or raising it), so that the hard limit can 3584 later be used as a safe reset point for the soft limit 3585 upon context transitions. See selinux_bprm_committing_creds. */ 3586 if (old_rlim->rlim_max != new_rlim->rlim_max) 3587 return current_has_perm(p, PROCESS__SETRLIMIT); 3588 3589 return 0; 3590 } 3591 3592 static int selinux_task_setscheduler(struct task_struct *p) 3593 { 3594 int rc; 3595 3596 rc = cap_task_setscheduler(p); 3597 if (rc) 3598 return rc; 3599 3600 return current_has_perm(p, PROCESS__SETSCHED); 3601 } 3602 3603 static int selinux_task_getscheduler(struct task_struct *p) 3604 { 3605 return current_has_perm(p, PROCESS__GETSCHED); 3606 } 3607 3608 static int selinux_task_movememory(struct task_struct *p) 3609 { 3610 return current_has_perm(p, PROCESS__SETSCHED); 3611 } 3612 3613 static int selinux_task_kill(struct task_struct *p, struct siginfo *info, 3614 int sig, u32 secid) 3615 { 3616 u32 perm; 3617 int rc; 3618 3619 if (!sig) 3620 perm = PROCESS__SIGNULL; /* null signal; existence test */ 3621 else 3622 perm = signal_to_av(sig); 3623 if (secid) 3624 rc = avc_has_perm(secid, task_sid(p), 3625 SECCLASS_PROCESS, perm, NULL); 3626 else 3627 rc = current_has_perm(p, perm); 3628 return rc; 3629 } 3630 3631 static int selinux_task_wait(struct task_struct *p) 3632 { 3633 return task_has_perm(p, current, PROCESS__SIGCHLD); 3634 } 3635 3636 static void selinux_task_to_inode(struct task_struct *p, 3637 struct inode *inode) 3638 { 3639 struct inode_security_struct *isec = inode->i_security; 3640 u32 sid = task_sid(p); 3641 3642 isec->sid = sid; 3643 isec->initialized = 1; 3644 } 3645 3646 /* Returns error only if unable to parse addresses */ 3647 static int selinux_parse_skb_ipv4(struct sk_buff *skb, 3648 struct common_audit_data *ad, u8 *proto) 3649 { 3650 int offset, ihlen, ret = -EINVAL; 3651 struct iphdr _iph, *ih; 3652 3653 offset = skb_network_offset(skb); 3654 ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph); 3655 if (ih == NULL) 3656 goto out; 3657 3658 ihlen = ih->ihl * 4; 3659 if (ihlen < sizeof(_iph)) 3660 goto out; 3661 3662 ad->u.net->v4info.saddr = ih->saddr; 3663 ad->u.net->v4info.daddr = ih->daddr; 3664 ret = 0; 3665 3666 if (proto) 3667 *proto = ih->protocol; 3668 3669 switch (ih->protocol) { 3670 case IPPROTO_TCP: { 3671 struct tcphdr _tcph, *th; 3672 3673 if (ntohs(ih->frag_off) & IP_OFFSET) 3674 break; 3675 3676 offset += ihlen; 3677 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); 3678 if (th == NULL) 3679 break; 3680 3681 ad->u.net->sport = th->source; 3682 ad->u.net->dport = th->dest; 3683 break; 3684 } 3685 3686 case IPPROTO_UDP: { 3687 struct udphdr _udph, *uh; 3688 3689 if (ntohs(ih->frag_off) & IP_OFFSET) 3690 break; 3691 3692 offset += ihlen; 3693 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); 3694 if (uh == NULL) 3695 break; 3696 3697 ad->u.net->sport = uh->source; 3698 ad->u.net->dport = uh->dest; 3699 break; 3700 } 3701 3702 case IPPROTO_DCCP: { 3703 struct dccp_hdr _dccph, *dh; 3704 3705 if (ntohs(ih->frag_off) & IP_OFFSET) 3706 break; 3707 3708 offset += ihlen; 3709 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); 3710 if (dh == NULL) 3711 break; 3712 3713 ad->u.net->sport = dh->dccph_sport; 3714 ad->u.net->dport = dh->dccph_dport; 3715 break; 3716 } 3717 3718 default: 3719 break; 3720 } 3721 out: 3722 return ret; 3723 } 3724 3725 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 3726 3727 /* Returns error only if unable to parse addresses */ 3728 static int selinux_parse_skb_ipv6(struct sk_buff *skb, 3729 struct common_audit_data *ad, u8 *proto) 3730 { 3731 u8 nexthdr; 3732 int ret = -EINVAL, offset; 3733 struct ipv6hdr _ipv6h, *ip6; 3734 __be16 frag_off; 3735 3736 offset = skb_network_offset(skb); 3737 ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h); 3738 if (ip6 == NULL) 3739 goto out; 3740 3741 ad->u.net->v6info.saddr = ip6->saddr; 3742 ad->u.net->v6info.daddr = ip6->daddr; 3743 ret = 0; 3744 3745 nexthdr = ip6->nexthdr; 3746 offset += sizeof(_ipv6h); 3747 offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off); 3748 if (offset < 0) 3749 goto out; 3750 3751 if (proto) 3752 *proto = nexthdr; 3753 3754 switch (nexthdr) { 3755 case IPPROTO_TCP: { 3756 struct tcphdr _tcph, *th; 3757 3758 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); 3759 if (th == NULL) 3760 break; 3761 3762 ad->u.net->sport = th->source; 3763 ad->u.net->dport = th->dest; 3764 break; 3765 } 3766 3767 case IPPROTO_UDP: { 3768 struct udphdr _udph, *uh; 3769 3770 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); 3771 if (uh == NULL) 3772 break; 3773 3774 ad->u.net->sport = uh->source; 3775 ad->u.net->dport = uh->dest; 3776 break; 3777 } 3778 3779 case IPPROTO_DCCP: { 3780 struct dccp_hdr _dccph, *dh; 3781 3782 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph); 3783 if (dh == NULL) 3784 break; 3785 3786 ad->u.net->sport = dh->dccph_sport; 3787 ad->u.net->dport = dh->dccph_dport; 3788 break; 3789 } 3790 3791 /* includes fragments */ 3792 default: 3793 break; 3794 } 3795 out: 3796 return ret; 3797 } 3798 3799 #endif /* IPV6 */ 3800 3801 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad, 3802 char **_addrp, int src, u8 *proto) 3803 { 3804 char *addrp; 3805 int ret; 3806 3807 switch (ad->u.net->family) { 3808 case PF_INET: 3809 ret = selinux_parse_skb_ipv4(skb, ad, proto); 3810 if (ret) 3811 goto parse_error; 3812 addrp = (char *)(src ? &ad->u.net->v4info.saddr : 3813 &ad->u.net->v4info.daddr); 3814 goto okay; 3815 3816 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 3817 case PF_INET6: 3818 ret = selinux_parse_skb_ipv6(skb, ad, proto); 3819 if (ret) 3820 goto parse_error; 3821 addrp = (char *)(src ? &ad->u.net->v6info.saddr : 3822 &ad->u.net->v6info.daddr); 3823 goto okay; 3824 #endif /* IPV6 */ 3825 default: 3826 addrp = NULL; 3827 goto okay; 3828 } 3829 3830 parse_error: 3831 printk(KERN_WARNING 3832 "SELinux: failure in selinux_parse_skb()," 3833 " unable to parse packet\n"); 3834 return ret; 3835 3836 okay: 3837 if (_addrp) 3838 *_addrp = addrp; 3839 return 0; 3840 } 3841 3842 /** 3843 * selinux_skb_peerlbl_sid - Determine the peer label of a packet 3844 * @skb: the packet 3845 * @family: protocol family 3846 * @sid: the packet's peer label SID 3847 * 3848 * Description: 3849 * Check the various different forms of network peer labeling and determine 3850 * the peer label/SID for the packet; most of the magic actually occurs in 3851 * the security server function security_net_peersid_cmp(). The function 3852 * returns zero if the value in @sid is valid (although it may be SECSID_NULL) 3853 * or -EACCES if @sid is invalid due to inconsistencies with the different 3854 * peer labels. 3855 * 3856 */ 3857 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid) 3858 { 3859 int err; 3860 u32 xfrm_sid; 3861 u32 nlbl_sid; 3862 u32 nlbl_type; 3863 3864 err = selinux_xfrm_skb_sid(skb, &xfrm_sid); 3865 if (unlikely(err)) 3866 return -EACCES; 3867 err = selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid); 3868 if (unlikely(err)) 3869 return -EACCES; 3870 3871 err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid); 3872 if (unlikely(err)) { 3873 printk(KERN_WARNING 3874 "SELinux: failure in selinux_skb_peerlbl_sid()," 3875 " unable to determine packet's peer label\n"); 3876 return -EACCES; 3877 } 3878 3879 return 0; 3880 } 3881 3882 /** 3883 * selinux_conn_sid - Determine the child socket label for a connection 3884 * @sk_sid: the parent socket's SID 3885 * @skb_sid: the packet's SID 3886 * @conn_sid: the resulting connection SID 3887 * 3888 * If @skb_sid is valid then the user:role:type information from @sk_sid is 3889 * combined with the MLS information from @skb_sid in order to create 3890 * @conn_sid. If @skb_sid is not valid then then @conn_sid is simply a copy 3891 * of @sk_sid. Returns zero on success, negative values on failure. 3892 * 3893 */ 3894 static int selinux_conn_sid(u32 sk_sid, u32 skb_sid, u32 *conn_sid) 3895 { 3896 int err = 0; 3897 3898 if (skb_sid != SECSID_NULL) 3899 err = security_sid_mls_copy(sk_sid, skb_sid, conn_sid); 3900 else 3901 *conn_sid = sk_sid; 3902 3903 return err; 3904 } 3905 3906 /* socket security operations */ 3907 3908 static int socket_sockcreate_sid(const struct task_security_struct *tsec, 3909 u16 secclass, u32 *socksid) 3910 { 3911 if (tsec->sockcreate_sid > SECSID_NULL) { 3912 *socksid = tsec->sockcreate_sid; 3913 return 0; 3914 } 3915 3916 return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL, 3917 socksid); 3918 } 3919 3920 static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms) 3921 { 3922 struct sk_security_struct *sksec = sk->sk_security; 3923 struct common_audit_data ad; 3924 struct lsm_network_audit net = {0,}; 3925 u32 tsid = task_sid(task); 3926 3927 if (sksec->sid == SECINITSID_KERNEL) 3928 return 0; 3929 3930 ad.type = LSM_AUDIT_DATA_NET; 3931 ad.u.net = &net; 3932 ad.u.net->sk = sk; 3933 3934 return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad); 3935 } 3936 3937 static int selinux_socket_create(int family, int type, 3938 int protocol, int kern) 3939 { 3940 const struct task_security_struct *tsec = current_security(); 3941 u32 newsid; 3942 u16 secclass; 3943 int rc; 3944 3945 if (kern) 3946 return 0; 3947 3948 secclass = socket_type_to_security_class(family, type, protocol); 3949 rc = socket_sockcreate_sid(tsec, secclass, &newsid); 3950 if (rc) 3951 return rc; 3952 3953 return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL); 3954 } 3955 3956 static int selinux_socket_post_create(struct socket *sock, int family, 3957 int type, int protocol, int kern) 3958 { 3959 const struct task_security_struct *tsec = current_security(); 3960 struct inode_security_struct *isec = SOCK_INODE(sock)->i_security; 3961 struct sk_security_struct *sksec; 3962 int err = 0; 3963 3964 isec->sclass = socket_type_to_security_class(family, type, protocol); 3965 3966 if (kern) 3967 isec->sid = SECINITSID_KERNEL; 3968 else { 3969 err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid)); 3970 if (err) 3971 return err; 3972 } 3973 3974 isec->initialized = 1; 3975 3976 if (sock->sk) { 3977 sksec = sock->sk->sk_security; 3978 sksec->sid = isec->sid; 3979 sksec->sclass = isec->sclass; 3980 err = selinux_netlbl_socket_post_create(sock->sk, family); 3981 } 3982 3983 return err; 3984 } 3985 3986 /* Range of port numbers used to automatically bind. 3987 Need to determine whether we should perform a name_bind 3988 permission check between the socket and the port number. */ 3989 3990 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen) 3991 { 3992 struct sock *sk = sock->sk; 3993 u16 family; 3994 int err; 3995 3996 err = sock_has_perm(current, sk, SOCKET__BIND); 3997 if (err) 3998 goto out; 3999 4000 /* 4001 * If PF_INET or PF_INET6, check name_bind permission for the port. 4002 * Multiple address binding for SCTP is not supported yet: we just 4003 * check the first address now. 4004 */ 4005 family = sk->sk_family; 4006 if (family == PF_INET || family == PF_INET6) { 4007 char *addrp; 4008 struct sk_security_struct *sksec = sk->sk_security; 4009 struct common_audit_data ad; 4010 struct lsm_network_audit net = {0,}; 4011 struct sockaddr_in *addr4 = NULL; 4012 struct sockaddr_in6 *addr6 = NULL; 4013 unsigned short snum; 4014 u32 sid, node_perm; 4015 4016 if (family == PF_INET) { 4017 addr4 = (struct sockaddr_in *)address; 4018 snum = ntohs(addr4->sin_port); 4019 addrp = (char *)&addr4->sin_addr.s_addr; 4020 } else { 4021 addr6 = (struct sockaddr_in6 *)address; 4022 snum = ntohs(addr6->sin6_port); 4023 addrp = (char *)&addr6->sin6_addr.s6_addr; 4024 } 4025 4026 if (snum) { 4027 int low, high; 4028 4029 inet_get_local_port_range(sock_net(sk), &low, &high); 4030 4031 if (snum < max(PROT_SOCK, low) || snum > high) { 4032 err = sel_netport_sid(sk->sk_protocol, 4033 snum, &sid); 4034 if (err) 4035 goto out; 4036 ad.type = LSM_AUDIT_DATA_NET; 4037 ad.u.net = &net; 4038 ad.u.net->sport = htons(snum); 4039 ad.u.net->family = family; 4040 err = avc_has_perm(sksec->sid, sid, 4041 sksec->sclass, 4042 SOCKET__NAME_BIND, &ad); 4043 if (err) 4044 goto out; 4045 } 4046 } 4047 4048 switch (sksec->sclass) { 4049 case SECCLASS_TCP_SOCKET: 4050 node_perm = TCP_SOCKET__NODE_BIND; 4051 break; 4052 4053 case SECCLASS_UDP_SOCKET: 4054 node_perm = UDP_SOCKET__NODE_BIND; 4055 break; 4056 4057 case SECCLASS_DCCP_SOCKET: 4058 node_perm = DCCP_SOCKET__NODE_BIND; 4059 break; 4060 4061 default: 4062 node_perm = RAWIP_SOCKET__NODE_BIND; 4063 break; 4064 } 4065 4066 err = sel_netnode_sid(addrp, family, &sid); 4067 if (err) 4068 goto out; 4069 4070 ad.type = LSM_AUDIT_DATA_NET; 4071 ad.u.net = &net; 4072 ad.u.net->sport = htons(snum); 4073 ad.u.net->family = family; 4074 4075 if (family == PF_INET) 4076 ad.u.net->v4info.saddr = addr4->sin_addr.s_addr; 4077 else 4078 ad.u.net->v6info.saddr = addr6->sin6_addr; 4079 4080 err = avc_has_perm(sksec->sid, sid, 4081 sksec->sclass, node_perm, &ad); 4082 if (err) 4083 goto out; 4084 } 4085 out: 4086 return err; 4087 } 4088 4089 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen) 4090 { 4091 struct sock *sk = sock->sk; 4092 struct sk_security_struct *sksec = sk->sk_security; 4093 int err; 4094 4095 err = sock_has_perm(current, sk, SOCKET__CONNECT); 4096 if (err) 4097 return err; 4098 4099 /* 4100 * If a TCP or DCCP socket, check name_connect permission for the port. 4101 */ 4102 if (sksec->sclass == SECCLASS_TCP_SOCKET || 4103 sksec->sclass == SECCLASS_DCCP_SOCKET) { 4104 struct common_audit_data ad; 4105 struct lsm_network_audit net = {0,}; 4106 struct sockaddr_in *addr4 = NULL; 4107 struct sockaddr_in6 *addr6 = NULL; 4108 unsigned short snum; 4109 u32 sid, perm; 4110 4111 if (sk->sk_family == PF_INET) { 4112 addr4 = (struct sockaddr_in *)address; 4113 if (addrlen < sizeof(struct sockaddr_in)) 4114 return -EINVAL; 4115 snum = ntohs(addr4->sin_port); 4116 } else { 4117 addr6 = (struct sockaddr_in6 *)address; 4118 if (addrlen < SIN6_LEN_RFC2133) 4119 return -EINVAL; 4120 snum = ntohs(addr6->sin6_port); 4121 } 4122 4123 err = sel_netport_sid(sk->sk_protocol, snum, &sid); 4124 if (err) 4125 goto out; 4126 4127 perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ? 4128 TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT; 4129 4130 ad.type = LSM_AUDIT_DATA_NET; 4131 ad.u.net = &net; 4132 ad.u.net->dport = htons(snum); 4133 ad.u.net->family = sk->sk_family; 4134 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad); 4135 if (err) 4136 goto out; 4137 } 4138 4139 err = selinux_netlbl_socket_connect(sk, address); 4140 4141 out: 4142 return err; 4143 } 4144 4145 static int selinux_socket_listen(struct socket *sock, int backlog) 4146 { 4147 return sock_has_perm(current, sock->sk, SOCKET__LISTEN); 4148 } 4149 4150 static int selinux_socket_accept(struct socket *sock, struct socket *newsock) 4151 { 4152 int err; 4153 struct inode_security_struct *isec; 4154 struct inode_security_struct *newisec; 4155 4156 err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT); 4157 if (err) 4158 return err; 4159 4160 newisec = SOCK_INODE(newsock)->i_security; 4161 4162 isec = SOCK_INODE(sock)->i_security; 4163 newisec->sclass = isec->sclass; 4164 newisec->sid = isec->sid; 4165 newisec->initialized = 1; 4166 4167 return 0; 4168 } 4169 4170 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg, 4171 int size) 4172 { 4173 return sock_has_perm(current, sock->sk, SOCKET__WRITE); 4174 } 4175 4176 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg, 4177 int size, int flags) 4178 { 4179 return sock_has_perm(current, sock->sk, SOCKET__READ); 4180 } 4181 4182 static int selinux_socket_getsockname(struct socket *sock) 4183 { 4184 return sock_has_perm(current, sock->sk, SOCKET__GETATTR); 4185 } 4186 4187 static int selinux_socket_getpeername(struct socket *sock) 4188 { 4189 return sock_has_perm(current, sock->sk, SOCKET__GETATTR); 4190 } 4191 4192 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname) 4193 { 4194 int err; 4195 4196 err = sock_has_perm(current, sock->sk, SOCKET__SETOPT); 4197 if (err) 4198 return err; 4199 4200 return selinux_netlbl_socket_setsockopt(sock, level, optname); 4201 } 4202 4203 static int selinux_socket_getsockopt(struct socket *sock, int level, 4204 int optname) 4205 { 4206 return sock_has_perm(current, sock->sk, SOCKET__GETOPT); 4207 } 4208 4209 static int selinux_socket_shutdown(struct socket *sock, int how) 4210 { 4211 return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN); 4212 } 4213 4214 static int selinux_socket_unix_stream_connect(struct sock *sock, 4215 struct sock *other, 4216 struct sock *newsk) 4217 { 4218 struct sk_security_struct *sksec_sock = sock->sk_security; 4219 struct sk_security_struct *sksec_other = other->sk_security; 4220 struct sk_security_struct *sksec_new = newsk->sk_security; 4221 struct common_audit_data ad; 4222 struct lsm_network_audit net = {0,}; 4223 int err; 4224 4225 ad.type = LSM_AUDIT_DATA_NET; 4226 ad.u.net = &net; 4227 ad.u.net->sk = other; 4228 4229 err = avc_has_perm(sksec_sock->sid, sksec_other->sid, 4230 sksec_other->sclass, 4231 UNIX_STREAM_SOCKET__CONNECTTO, &ad); 4232 if (err) 4233 return err; 4234 4235 /* server child socket */ 4236 sksec_new->peer_sid = sksec_sock->sid; 4237 err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid, 4238 &sksec_new->sid); 4239 if (err) 4240 return err; 4241 4242 /* connecting socket */ 4243 sksec_sock->peer_sid = sksec_new->sid; 4244 4245 return 0; 4246 } 4247 4248 static int selinux_socket_unix_may_send(struct socket *sock, 4249 struct socket *other) 4250 { 4251 struct sk_security_struct *ssec = sock->sk->sk_security; 4252 struct sk_security_struct *osec = other->sk->sk_security; 4253 struct common_audit_data ad; 4254 struct lsm_network_audit net = {0,}; 4255 4256 ad.type = LSM_AUDIT_DATA_NET; 4257 ad.u.net = &net; 4258 ad.u.net->sk = other->sk; 4259 4260 return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO, 4261 &ad); 4262 } 4263 4264 static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family, 4265 u32 peer_sid, 4266 struct common_audit_data *ad) 4267 { 4268 int err; 4269 u32 if_sid; 4270 u32 node_sid; 4271 4272 err = sel_netif_sid(ifindex, &if_sid); 4273 if (err) 4274 return err; 4275 err = avc_has_perm(peer_sid, if_sid, 4276 SECCLASS_NETIF, NETIF__INGRESS, ad); 4277 if (err) 4278 return err; 4279 4280 err = sel_netnode_sid(addrp, family, &node_sid); 4281 if (err) 4282 return err; 4283 return avc_has_perm(peer_sid, node_sid, 4284 SECCLASS_NODE, NODE__RECVFROM, ad); 4285 } 4286 4287 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb, 4288 u16 family) 4289 { 4290 int err = 0; 4291 struct sk_security_struct *sksec = sk->sk_security; 4292 u32 sk_sid = sksec->sid; 4293 struct common_audit_data ad; 4294 struct lsm_network_audit net = {0,}; 4295 char *addrp; 4296 4297 ad.type = LSM_AUDIT_DATA_NET; 4298 ad.u.net = &net; 4299 ad.u.net->netif = skb->skb_iif; 4300 ad.u.net->family = family; 4301 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); 4302 if (err) 4303 return err; 4304 4305 if (selinux_secmark_enabled()) { 4306 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, 4307 PACKET__RECV, &ad); 4308 if (err) 4309 return err; 4310 } 4311 4312 err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad); 4313 if (err) 4314 return err; 4315 err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad); 4316 4317 return err; 4318 } 4319 4320 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 4321 { 4322 int err; 4323 struct sk_security_struct *sksec = sk->sk_security; 4324 u16 family = sk->sk_family; 4325 u32 sk_sid = sksec->sid; 4326 struct common_audit_data ad; 4327 struct lsm_network_audit net = {0,}; 4328 char *addrp; 4329 u8 secmark_active; 4330 u8 peerlbl_active; 4331 4332 if (family != PF_INET && family != PF_INET6) 4333 return 0; 4334 4335 /* Handle mapped IPv4 packets arriving via IPv6 sockets */ 4336 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4337 family = PF_INET; 4338 4339 /* If any sort of compatibility mode is enabled then handoff processing 4340 * to the selinux_sock_rcv_skb_compat() function to deal with the 4341 * special handling. We do this in an attempt to keep this function 4342 * as fast and as clean as possible. */ 4343 if (!selinux_policycap_netpeer) 4344 return selinux_sock_rcv_skb_compat(sk, skb, family); 4345 4346 secmark_active = selinux_secmark_enabled(); 4347 peerlbl_active = selinux_peerlbl_enabled(); 4348 if (!secmark_active && !peerlbl_active) 4349 return 0; 4350 4351 ad.type = LSM_AUDIT_DATA_NET; 4352 ad.u.net = &net; 4353 ad.u.net->netif = skb->skb_iif; 4354 ad.u.net->family = family; 4355 err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL); 4356 if (err) 4357 return err; 4358 4359 if (peerlbl_active) { 4360 u32 peer_sid; 4361 4362 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid); 4363 if (err) 4364 return err; 4365 err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family, 4366 peer_sid, &ad); 4367 if (err) { 4368 selinux_netlbl_err(skb, err, 0); 4369 return err; 4370 } 4371 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER, 4372 PEER__RECV, &ad); 4373 if (err) { 4374 selinux_netlbl_err(skb, err, 0); 4375 return err; 4376 } 4377 } 4378 4379 if (secmark_active) { 4380 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET, 4381 PACKET__RECV, &ad); 4382 if (err) 4383 return err; 4384 } 4385 4386 return err; 4387 } 4388 4389 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval, 4390 int __user *optlen, unsigned len) 4391 { 4392 int err = 0; 4393 char *scontext; 4394 u32 scontext_len; 4395 struct sk_security_struct *sksec = sock->sk->sk_security; 4396 u32 peer_sid = SECSID_NULL; 4397 4398 if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET || 4399 sksec->sclass == SECCLASS_TCP_SOCKET) 4400 peer_sid = sksec->peer_sid; 4401 if (peer_sid == SECSID_NULL) 4402 return -ENOPROTOOPT; 4403 4404 err = security_sid_to_context(peer_sid, &scontext, &scontext_len); 4405 if (err) 4406 return err; 4407 4408 if (scontext_len > len) { 4409 err = -ERANGE; 4410 goto out_len; 4411 } 4412 4413 if (copy_to_user(optval, scontext, scontext_len)) 4414 err = -EFAULT; 4415 4416 out_len: 4417 if (put_user(scontext_len, optlen)) 4418 err = -EFAULT; 4419 kfree(scontext); 4420 return err; 4421 } 4422 4423 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid) 4424 { 4425 u32 peer_secid = SECSID_NULL; 4426 u16 family; 4427 4428 if (skb && skb->protocol == htons(ETH_P_IP)) 4429 family = PF_INET; 4430 else if (skb && skb->protocol == htons(ETH_P_IPV6)) 4431 family = PF_INET6; 4432 else if (sock) 4433 family = sock->sk->sk_family; 4434 else 4435 goto out; 4436 4437 if (sock && family == PF_UNIX) 4438 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid); 4439 else if (skb) 4440 selinux_skb_peerlbl_sid(skb, family, &peer_secid); 4441 4442 out: 4443 *secid = peer_secid; 4444 if (peer_secid == SECSID_NULL) 4445 return -EINVAL; 4446 return 0; 4447 } 4448 4449 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority) 4450 { 4451 struct sk_security_struct *sksec; 4452 4453 sksec = kzalloc(sizeof(*sksec), priority); 4454 if (!sksec) 4455 return -ENOMEM; 4456 4457 sksec->peer_sid = SECINITSID_UNLABELED; 4458 sksec->sid = SECINITSID_UNLABELED; 4459 selinux_netlbl_sk_security_reset(sksec); 4460 sk->sk_security = sksec; 4461 4462 return 0; 4463 } 4464 4465 static void selinux_sk_free_security(struct sock *sk) 4466 { 4467 struct sk_security_struct *sksec = sk->sk_security; 4468 4469 sk->sk_security = NULL; 4470 selinux_netlbl_sk_security_free(sksec); 4471 kfree(sksec); 4472 } 4473 4474 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk) 4475 { 4476 struct sk_security_struct *sksec = sk->sk_security; 4477 struct sk_security_struct *newsksec = newsk->sk_security; 4478 4479 newsksec->sid = sksec->sid; 4480 newsksec->peer_sid = sksec->peer_sid; 4481 newsksec->sclass = sksec->sclass; 4482 4483 selinux_netlbl_sk_security_reset(newsksec); 4484 } 4485 4486 static void selinux_sk_getsecid(struct sock *sk, u32 *secid) 4487 { 4488 if (!sk) 4489 *secid = SECINITSID_ANY_SOCKET; 4490 else { 4491 struct sk_security_struct *sksec = sk->sk_security; 4492 4493 *secid = sksec->sid; 4494 } 4495 } 4496 4497 static void selinux_sock_graft(struct sock *sk, struct socket *parent) 4498 { 4499 struct inode_security_struct *isec = SOCK_INODE(parent)->i_security; 4500 struct sk_security_struct *sksec = sk->sk_security; 4501 4502 if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 || 4503 sk->sk_family == PF_UNIX) 4504 isec->sid = sksec->sid; 4505 sksec->sclass = isec->sclass; 4506 } 4507 4508 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb, 4509 struct request_sock *req) 4510 { 4511 struct sk_security_struct *sksec = sk->sk_security; 4512 int err; 4513 u16 family = req->rsk_ops->family; 4514 u32 connsid; 4515 u32 peersid; 4516 4517 err = selinux_skb_peerlbl_sid(skb, family, &peersid); 4518 if (err) 4519 return err; 4520 err = selinux_conn_sid(sksec->sid, peersid, &connsid); 4521 if (err) 4522 return err; 4523 req->secid = connsid; 4524 req->peer_secid = peersid; 4525 4526 return selinux_netlbl_inet_conn_request(req, family); 4527 } 4528 4529 static void selinux_inet_csk_clone(struct sock *newsk, 4530 const struct request_sock *req) 4531 { 4532 struct sk_security_struct *newsksec = newsk->sk_security; 4533 4534 newsksec->sid = req->secid; 4535 newsksec->peer_sid = req->peer_secid; 4536 /* NOTE: Ideally, we should also get the isec->sid for the 4537 new socket in sync, but we don't have the isec available yet. 4538 So we will wait until sock_graft to do it, by which 4539 time it will have been created and available. */ 4540 4541 /* We don't need to take any sort of lock here as we are the only 4542 * thread with access to newsksec */ 4543 selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family); 4544 } 4545 4546 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb) 4547 { 4548 u16 family = sk->sk_family; 4549 struct sk_security_struct *sksec = sk->sk_security; 4550 4551 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 4552 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 4553 family = PF_INET; 4554 4555 selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid); 4556 } 4557 4558 static void selinux_skb_owned_by(struct sk_buff *skb, struct sock *sk) 4559 { 4560 skb_set_owner_w(skb, sk); 4561 } 4562 4563 static int selinux_secmark_relabel_packet(u32 sid) 4564 { 4565 const struct task_security_struct *__tsec; 4566 u32 tsid; 4567 4568 __tsec = current_security(); 4569 tsid = __tsec->sid; 4570 4571 return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL); 4572 } 4573 4574 static void selinux_secmark_refcount_inc(void) 4575 { 4576 atomic_inc(&selinux_secmark_refcount); 4577 } 4578 4579 static void selinux_secmark_refcount_dec(void) 4580 { 4581 atomic_dec(&selinux_secmark_refcount); 4582 } 4583 4584 static void selinux_req_classify_flow(const struct request_sock *req, 4585 struct flowi *fl) 4586 { 4587 fl->flowi_secid = req->secid; 4588 } 4589 4590 static int selinux_tun_dev_alloc_security(void **security) 4591 { 4592 struct tun_security_struct *tunsec; 4593 4594 tunsec = kzalloc(sizeof(*tunsec), GFP_KERNEL); 4595 if (!tunsec) 4596 return -ENOMEM; 4597 tunsec->sid = current_sid(); 4598 4599 *security = tunsec; 4600 return 0; 4601 } 4602 4603 static void selinux_tun_dev_free_security(void *security) 4604 { 4605 kfree(security); 4606 } 4607 4608 static int selinux_tun_dev_create(void) 4609 { 4610 u32 sid = current_sid(); 4611 4612 /* we aren't taking into account the "sockcreate" SID since the socket 4613 * that is being created here is not a socket in the traditional sense, 4614 * instead it is a private sock, accessible only to the kernel, and 4615 * representing a wide range of network traffic spanning multiple 4616 * connections unlike traditional sockets - check the TUN driver to 4617 * get a better understanding of why this socket is special */ 4618 4619 return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE, 4620 NULL); 4621 } 4622 4623 static int selinux_tun_dev_attach_queue(void *security) 4624 { 4625 struct tun_security_struct *tunsec = security; 4626 4627 return avc_has_perm(current_sid(), tunsec->sid, SECCLASS_TUN_SOCKET, 4628 TUN_SOCKET__ATTACH_QUEUE, NULL); 4629 } 4630 4631 static int selinux_tun_dev_attach(struct sock *sk, void *security) 4632 { 4633 struct tun_security_struct *tunsec = security; 4634 struct sk_security_struct *sksec = sk->sk_security; 4635 4636 /* we don't currently perform any NetLabel based labeling here and it 4637 * isn't clear that we would want to do so anyway; while we could apply 4638 * labeling without the support of the TUN user the resulting labeled 4639 * traffic from the other end of the connection would almost certainly 4640 * cause confusion to the TUN user that had no idea network labeling 4641 * protocols were being used */ 4642 4643 sksec->sid = tunsec->sid; 4644 sksec->sclass = SECCLASS_TUN_SOCKET; 4645 4646 return 0; 4647 } 4648 4649 static int selinux_tun_dev_open(void *security) 4650 { 4651 struct tun_security_struct *tunsec = security; 4652 u32 sid = current_sid(); 4653 int err; 4654 4655 err = avc_has_perm(sid, tunsec->sid, SECCLASS_TUN_SOCKET, 4656 TUN_SOCKET__RELABELFROM, NULL); 4657 if (err) 4658 return err; 4659 err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, 4660 TUN_SOCKET__RELABELTO, NULL); 4661 if (err) 4662 return err; 4663 tunsec->sid = sid; 4664 4665 return 0; 4666 } 4667 4668 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb) 4669 { 4670 int err = 0; 4671 u32 perm; 4672 struct nlmsghdr *nlh; 4673 struct sk_security_struct *sksec = sk->sk_security; 4674 4675 if (skb->len < NLMSG_HDRLEN) { 4676 err = -EINVAL; 4677 goto out; 4678 } 4679 nlh = nlmsg_hdr(skb); 4680 4681 err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm); 4682 if (err) { 4683 if (err == -EINVAL) { 4684 audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR, 4685 "SELinux: unrecognized netlink message" 4686 " type=%hu for sclass=%hu\n", 4687 nlh->nlmsg_type, sksec->sclass); 4688 if (!selinux_enforcing || security_get_allow_unknown()) 4689 err = 0; 4690 } 4691 4692 /* Ignore */ 4693 if (err == -ENOENT) 4694 err = 0; 4695 goto out; 4696 } 4697 4698 err = sock_has_perm(current, sk, perm); 4699 out: 4700 return err; 4701 } 4702 4703 #ifdef CONFIG_NETFILTER 4704 4705 static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex, 4706 u16 family) 4707 { 4708 int err; 4709 char *addrp; 4710 u32 peer_sid; 4711 struct common_audit_data ad; 4712 struct lsm_network_audit net = {0,}; 4713 u8 secmark_active; 4714 u8 netlbl_active; 4715 u8 peerlbl_active; 4716 4717 if (!selinux_policycap_netpeer) 4718 return NF_ACCEPT; 4719 4720 secmark_active = selinux_secmark_enabled(); 4721 netlbl_active = netlbl_enabled(); 4722 peerlbl_active = selinux_peerlbl_enabled(); 4723 if (!secmark_active && !peerlbl_active) 4724 return NF_ACCEPT; 4725 4726 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0) 4727 return NF_DROP; 4728 4729 ad.type = LSM_AUDIT_DATA_NET; 4730 ad.u.net = &net; 4731 ad.u.net->netif = ifindex; 4732 ad.u.net->family = family; 4733 if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0) 4734 return NF_DROP; 4735 4736 if (peerlbl_active) { 4737 err = selinux_inet_sys_rcv_skb(ifindex, addrp, family, 4738 peer_sid, &ad); 4739 if (err) { 4740 selinux_netlbl_err(skb, err, 1); 4741 return NF_DROP; 4742 } 4743 } 4744 4745 if (secmark_active) 4746 if (avc_has_perm(peer_sid, skb->secmark, 4747 SECCLASS_PACKET, PACKET__FORWARD_IN, &ad)) 4748 return NF_DROP; 4749 4750 if (netlbl_active) 4751 /* we do this in the FORWARD path and not the POST_ROUTING 4752 * path because we want to make sure we apply the necessary 4753 * labeling before IPsec is applied so we can leverage AH 4754 * protection */ 4755 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0) 4756 return NF_DROP; 4757 4758 return NF_ACCEPT; 4759 } 4760 4761 static unsigned int selinux_ipv4_forward(const struct nf_hook_ops *ops, 4762 struct sk_buff *skb, 4763 const struct net_device *in, 4764 const struct net_device *out, 4765 int (*okfn)(struct sk_buff *)) 4766 { 4767 return selinux_ip_forward(skb, in->ifindex, PF_INET); 4768 } 4769 4770 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 4771 static unsigned int selinux_ipv6_forward(const struct nf_hook_ops *ops, 4772 struct sk_buff *skb, 4773 const struct net_device *in, 4774 const struct net_device *out, 4775 int (*okfn)(struct sk_buff *)) 4776 { 4777 return selinux_ip_forward(skb, in->ifindex, PF_INET6); 4778 } 4779 #endif /* IPV6 */ 4780 4781 static unsigned int selinux_ip_output(struct sk_buff *skb, 4782 u16 family) 4783 { 4784 struct sock *sk; 4785 u32 sid; 4786 4787 if (!netlbl_enabled()) 4788 return NF_ACCEPT; 4789 4790 /* we do this in the LOCAL_OUT path and not the POST_ROUTING path 4791 * because we want to make sure we apply the necessary labeling 4792 * before IPsec is applied so we can leverage AH protection */ 4793 sk = skb->sk; 4794 if (sk) { 4795 struct sk_security_struct *sksec; 4796 4797 if (sk->sk_state == TCP_LISTEN) 4798 /* if the socket is the listening state then this 4799 * packet is a SYN-ACK packet which means it needs to 4800 * be labeled based on the connection/request_sock and 4801 * not the parent socket. unfortunately, we can't 4802 * lookup the request_sock yet as it isn't queued on 4803 * the parent socket until after the SYN-ACK is sent. 4804 * the "solution" is to simply pass the packet as-is 4805 * as any IP option based labeling should be copied 4806 * from the initial connection request (in the IP 4807 * layer). it is far from ideal, but until we get a 4808 * security label in the packet itself this is the 4809 * best we can do. */ 4810 return NF_ACCEPT; 4811 4812 /* standard practice, label using the parent socket */ 4813 sksec = sk->sk_security; 4814 sid = sksec->sid; 4815 } else 4816 sid = SECINITSID_KERNEL; 4817 if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0) 4818 return NF_DROP; 4819 4820 return NF_ACCEPT; 4821 } 4822 4823 static unsigned int selinux_ipv4_output(const struct nf_hook_ops *ops, 4824 struct sk_buff *skb, 4825 const struct net_device *in, 4826 const struct net_device *out, 4827 int (*okfn)(struct sk_buff *)) 4828 { 4829 return selinux_ip_output(skb, PF_INET); 4830 } 4831 4832 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb, 4833 int ifindex, 4834 u16 family) 4835 { 4836 struct sock *sk = skb->sk; 4837 struct sk_security_struct *sksec; 4838 struct common_audit_data ad; 4839 struct lsm_network_audit net = {0,}; 4840 char *addrp; 4841 u8 proto; 4842 4843 if (sk == NULL) 4844 return NF_ACCEPT; 4845 sksec = sk->sk_security; 4846 4847 ad.type = LSM_AUDIT_DATA_NET; 4848 ad.u.net = &net; 4849 ad.u.net->netif = ifindex; 4850 ad.u.net->family = family; 4851 if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto)) 4852 return NF_DROP; 4853 4854 if (selinux_secmark_enabled()) 4855 if (avc_has_perm(sksec->sid, skb->secmark, 4856 SECCLASS_PACKET, PACKET__SEND, &ad)) 4857 return NF_DROP_ERR(-ECONNREFUSED); 4858 4859 if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto)) 4860 return NF_DROP_ERR(-ECONNREFUSED); 4861 4862 return NF_ACCEPT; 4863 } 4864 4865 static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex, 4866 u16 family) 4867 { 4868 u32 secmark_perm; 4869 u32 peer_sid; 4870 struct sock *sk; 4871 struct common_audit_data ad; 4872 struct lsm_network_audit net = {0,}; 4873 char *addrp; 4874 u8 secmark_active; 4875 u8 peerlbl_active; 4876 4877 /* If any sort of compatibility mode is enabled then handoff processing 4878 * to the selinux_ip_postroute_compat() function to deal with the 4879 * special handling. We do this in an attempt to keep this function 4880 * as fast and as clean as possible. */ 4881 if (!selinux_policycap_netpeer) 4882 return selinux_ip_postroute_compat(skb, ifindex, family); 4883 4884 secmark_active = selinux_secmark_enabled(); 4885 peerlbl_active = selinux_peerlbl_enabled(); 4886 if (!secmark_active && !peerlbl_active) 4887 return NF_ACCEPT; 4888 4889 sk = skb->sk; 4890 4891 #ifdef CONFIG_XFRM 4892 /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec 4893 * packet transformation so allow the packet to pass without any checks 4894 * since we'll have another chance to perform access control checks 4895 * when the packet is on it's final way out. 4896 * NOTE: there appear to be some IPv6 multicast cases where skb->dst 4897 * is NULL, in this case go ahead and apply access control. 4898 * NOTE: if this is a local socket (skb->sk != NULL) that is in the 4899 * TCP listening state we cannot wait until the XFRM processing 4900 * is done as we will miss out on the SA label if we do; 4901 * unfortunately, this means more work, but it is only once per 4902 * connection. */ 4903 if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL && 4904 !(sk != NULL && sk->sk_state == TCP_LISTEN)) 4905 return NF_ACCEPT; 4906 #endif 4907 4908 if (sk == NULL) { 4909 /* Without an associated socket the packet is either coming 4910 * from the kernel or it is being forwarded; check the packet 4911 * to determine which and if the packet is being forwarded 4912 * query the packet directly to determine the security label. */ 4913 if (skb->skb_iif) { 4914 secmark_perm = PACKET__FORWARD_OUT; 4915 if (selinux_skb_peerlbl_sid(skb, family, &peer_sid)) 4916 return NF_DROP; 4917 } else { 4918 secmark_perm = PACKET__SEND; 4919 peer_sid = SECINITSID_KERNEL; 4920 } 4921 } else if (sk->sk_state == TCP_LISTEN) { 4922 /* Locally generated packet but the associated socket is in the 4923 * listening state which means this is a SYN-ACK packet. In 4924 * this particular case the correct security label is assigned 4925 * to the connection/request_sock but unfortunately we can't 4926 * query the request_sock as it isn't queued on the parent 4927 * socket until after the SYN-ACK packet is sent; the only 4928 * viable choice is to regenerate the label like we do in 4929 * selinux_inet_conn_request(). See also selinux_ip_output() 4930 * for similar problems. */ 4931 u32 skb_sid; 4932 struct sk_security_struct *sksec = sk->sk_security; 4933 if (selinux_skb_peerlbl_sid(skb, family, &skb_sid)) 4934 return NF_DROP; 4935 /* At this point, if the returned skb peerlbl is SECSID_NULL 4936 * and the packet has been through at least one XFRM 4937 * transformation then we must be dealing with the "final" 4938 * form of labeled IPsec packet; since we've already applied 4939 * all of our access controls on this packet we can safely 4940 * pass the packet. */ 4941 if (skb_sid == SECSID_NULL) { 4942 switch (family) { 4943 case PF_INET: 4944 if (IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) 4945 return NF_ACCEPT; 4946 break; 4947 case PF_INET6: 4948 if (IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED) 4949 return NF_ACCEPT; 4950 default: 4951 return NF_DROP_ERR(-ECONNREFUSED); 4952 } 4953 } 4954 if (selinux_conn_sid(sksec->sid, skb_sid, &peer_sid)) 4955 return NF_DROP; 4956 secmark_perm = PACKET__SEND; 4957 } else { 4958 /* Locally generated packet, fetch the security label from the 4959 * associated socket. */ 4960 struct sk_security_struct *sksec = sk->sk_security; 4961 peer_sid = sksec->sid; 4962 secmark_perm = PACKET__SEND; 4963 } 4964 4965 ad.type = LSM_AUDIT_DATA_NET; 4966 ad.u.net = &net; 4967 ad.u.net->netif = ifindex; 4968 ad.u.net->family = family; 4969 if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL)) 4970 return NF_DROP; 4971 4972 if (secmark_active) 4973 if (avc_has_perm(peer_sid, skb->secmark, 4974 SECCLASS_PACKET, secmark_perm, &ad)) 4975 return NF_DROP_ERR(-ECONNREFUSED); 4976 4977 if (peerlbl_active) { 4978 u32 if_sid; 4979 u32 node_sid; 4980 4981 if (sel_netif_sid(ifindex, &if_sid)) 4982 return NF_DROP; 4983 if (avc_has_perm(peer_sid, if_sid, 4984 SECCLASS_NETIF, NETIF__EGRESS, &ad)) 4985 return NF_DROP_ERR(-ECONNREFUSED); 4986 4987 if (sel_netnode_sid(addrp, family, &node_sid)) 4988 return NF_DROP; 4989 if (avc_has_perm(peer_sid, node_sid, 4990 SECCLASS_NODE, NODE__SENDTO, &ad)) 4991 return NF_DROP_ERR(-ECONNREFUSED); 4992 } 4993 4994 return NF_ACCEPT; 4995 } 4996 4997 static unsigned int selinux_ipv4_postroute(const struct nf_hook_ops *ops, 4998 struct sk_buff *skb, 4999 const struct net_device *in, 5000 const struct net_device *out, 5001 int (*okfn)(struct sk_buff *)) 5002 { 5003 return selinux_ip_postroute(skb, out->ifindex, PF_INET); 5004 } 5005 5006 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 5007 static unsigned int selinux_ipv6_postroute(const struct nf_hook_ops *ops, 5008 struct sk_buff *skb, 5009 const struct net_device *in, 5010 const struct net_device *out, 5011 int (*okfn)(struct sk_buff *)) 5012 { 5013 return selinux_ip_postroute(skb, out->ifindex, PF_INET6); 5014 } 5015 #endif /* IPV6 */ 5016 5017 #endif /* CONFIG_NETFILTER */ 5018 5019 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb) 5020 { 5021 int err; 5022 5023 err = cap_netlink_send(sk, skb); 5024 if (err) 5025 return err; 5026 5027 return selinux_nlmsg_perm(sk, skb); 5028 } 5029 5030 static int ipc_alloc_security(struct task_struct *task, 5031 struct kern_ipc_perm *perm, 5032 u16 sclass) 5033 { 5034 struct ipc_security_struct *isec; 5035 u32 sid; 5036 5037 isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL); 5038 if (!isec) 5039 return -ENOMEM; 5040 5041 sid = task_sid(task); 5042 isec->sclass = sclass; 5043 isec->sid = sid; 5044 perm->security = isec; 5045 5046 return 0; 5047 } 5048 5049 static void ipc_free_security(struct kern_ipc_perm *perm) 5050 { 5051 struct ipc_security_struct *isec = perm->security; 5052 perm->security = NULL; 5053 kfree(isec); 5054 } 5055 5056 static int msg_msg_alloc_security(struct msg_msg *msg) 5057 { 5058 struct msg_security_struct *msec; 5059 5060 msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL); 5061 if (!msec) 5062 return -ENOMEM; 5063 5064 msec->sid = SECINITSID_UNLABELED; 5065 msg->security = msec; 5066 5067 return 0; 5068 } 5069 5070 static void msg_msg_free_security(struct msg_msg *msg) 5071 { 5072 struct msg_security_struct *msec = msg->security; 5073 5074 msg->security = NULL; 5075 kfree(msec); 5076 } 5077 5078 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms, 5079 u32 perms) 5080 { 5081 struct ipc_security_struct *isec; 5082 struct common_audit_data ad; 5083 u32 sid = current_sid(); 5084 5085 isec = ipc_perms->security; 5086 5087 ad.type = LSM_AUDIT_DATA_IPC; 5088 ad.u.ipc_id = ipc_perms->key; 5089 5090 return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad); 5091 } 5092 5093 static int selinux_msg_msg_alloc_security(struct msg_msg *msg) 5094 { 5095 return msg_msg_alloc_security(msg); 5096 } 5097 5098 static void selinux_msg_msg_free_security(struct msg_msg *msg) 5099 { 5100 msg_msg_free_security(msg); 5101 } 5102 5103 /* message queue security operations */ 5104 static int selinux_msg_queue_alloc_security(struct msg_queue *msq) 5105 { 5106 struct ipc_security_struct *isec; 5107 struct common_audit_data ad; 5108 u32 sid = current_sid(); 5109 int rc; 5110 5111 rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ); 5112 if (rc) 5113 return rc; 5114 5115 isec = msq->q_perm.security; 5116 5117 ad.type = LSM_AUDIT_DATA_IPC; 5118 ad.u.ipc_id = msq->q_perm.key; 5119 5120 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 5121 MSGQ__CREATE, &ad); 5122 if (rc) { 5123 ipc_free_security(&msq->q_perm); 5124 return rc; 5125 } 5126 return 0; 5127 } 5128 5129 static void selinux_msg_queue_free_security(struct msg_queue *msq) 5130 { 5131 ipc_free_security(&msq->q_perm); 5132 } 5133 5134 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg) 5135 { 5136 struct ipc_security_struct *isec; 5137 struct common_audit_data ad; 5138 u32 sid = current_sid(); 5139 5140 isec = msq->q_perm.security; 5141 5142 ad.type = LSM_AUDIT_DATA_IPC; 5143 ad.u.ipc_id = msq->q_perm.key; 5144 5145 return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 5146 MSGQ__ASSOCIATE, &ad); 5147 } 5148 5149 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd) 5150 { 5151 int err; 5152 int perms; 5153 5154 switch (cmd) { 5155 case IPC_INFO: 5156 case MSG_INFO: 5157 /* No specific object, just general system-wide information. */ 5158 return task_has_system(current, SYSTEM__IPC_INFO); 5159 case IPC_STAT: 5160 case MSG_STAT: 5161 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE; 5162 break; 5163 case IPC_SET: 5164 perms = MSGQ__SETATTR; 5165 break; 5166 case IPC_RMID: 5167 perms = MSGQ__DESTROY; 5168 break; 5169 default: 5170 return 0; 5171 } 5172 5173 err = ipc_has_perm(&msq->q_perm, perms); 5174 return err; 5175 } 5176 5177 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg) 5178 { 5179 struct ipc_security_struct *isec; 5180 struct msg_security_struct *msec; 5181 struct common_audit_data ad; 5182 u32 sid = current_sid(); 5183 int rc; 5184 5185 isec = msq->q_perm.security; 5186 msec = msg->security; 5187 5188 /* 5189 * First time through, need to assign label to the message 5190 */ 5191 if (msec->sid == SECINITSID_UNLABELED) { 5192 /* 5193 * Compute new sid based on current process and 5194 * message queue this message will be stored in 5195 */ 5196 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG, 5197 NULL, &msec->sid); 5198 if (rc) 5199 return rc; 5200 } 5201 5202 ad.type = LSM_AUDIT_DATA_IPC; 5203 ad.u.ipc_id = msq->q_perm.key; 5204 5205 /* Can this process write to the queue? */ 5206 rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ, 5207 MSGQ__WRITE, &ad); 5208 if (!rc) 5209 /* Can this process send the message */ 5210 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG, 5211 MSG__SEND, &ad); 5212 if (!rc) 5213 /* Can the message be put in the queue? */ 5214 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ, 5215 MSGQ__ENQUEUE, &ad); 5216 5217 return rc; 5218 } 5219 5220 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, 5221 struct task_struct *target, 5222 long type, int mode) 5223 { 5224 struct ipc_security_struct *isec; 5225 struct msg_security_struct *msec; 5226 struct common_audit_data ad; 5227 u32 sid = task_sid(target); 5228 int rc; 5229 5230 isec = msq->q_perm.security; 5231 msec = msg->security; 5232 5233 ad.type = LSM_AUDIT_DATA_IPC; 5234 ad.u.ipc_id = msq->q_perm.key; 5235 5236 rc = avc_has_perm(sid, isec->sid, 5237 SECCLASS_MSGQ, MSGQ__READ, &ad); 5238 if (!rc) 5239 rc = avc_has_perm(sid, msec->sid, 5240 SECCLASS_MSG, MSG__RECEIVE, &ad); 5241 return rc; 5242 } 5243 5244 /* Shared Memory security operations */ 5245 static int selinux_shm_alloc_security(struct shmid_kernel *shp) 5246 { 5247 struct ipc_security_struct *isec; 5248 struct common_audit_data ad; 5249 u32 sid = current_sid(); 5250 int rc; 5251 5252 rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM); 5253 if (rc) 5254 return rc; 5255 5256 isec = shp->shm_perm.security; 5257 5258 ad.type = LSM_AUDIT_DATA_IPC; 5259 ad.u.ipc_id = shp->shm_perm.key; 5260 5261 rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM, 5262 SHM__CREATE, &ad); 5263 if (rc) { 5264 ipc_free_security(&shp->shm_perm); 5265 return rc; 5266 } 5267 return 0; 5268 } 5269 5270 static void selinux_shm_free_security(struct shmid_kernel *shp) 5271 { 5272 ipc_free_security(&shp->shm_perm); 5273 } 5274 5275 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg) 5276 { 5277 struct ipc_security_struct *isec; 5278 struct common_audit_data ad; 5279 u32 sid = current_sid(); 5280 5281 isec = shp->shm_perm.security; 5282 5283 ad.type = LSM_AUDIT_DATA_IPC; 5284 ad.u.ipc_id = shp->shm_perm.key; 5285 5286 return avc_has_perm(sid, isec->sid, SECCLASS_SHM, 5287 SHM__ASSOCIATE, &ad); 5288 } 5289 5290 /* Note, at this point, shp is locked down */ 5291 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd) 5292 { 5293 int perms; 5294 int err; 5295 5296 switch (cmd) { 5297 case IPC_INFO: 5298 case SHM_INFO: 5299 /* No specific object, just general system-wide information. */ 5300 return task_has_system(current, SYSTEM__IPC_INFO); 5301 case IPC_STAT: 5302 case SHM_STAT: 5303 perms = SHM__GETATTR | SHM__ASSOCIATE; 5304 break; 5305 case IPC_SET: 5306 perms = SHM__SETATTR; 5307 break; 5308 case SHM_LOCK: 5309 case SHM_UNLOCK: 5310 perms = SHM__LOCK; 5311 break; 5312 case IPC_RMID: 5313 perms = SHM__DESTROY; 5314 break; 5315 default: 5316 return 0; 5317 } 5318 5319 err = ipc_has_perm(&shp->shm_perm, perms); 5320 return err; 5321 } 5322 5323 static int selinux_shm_shmat(struct shmid_kernel *shp, 5324 char __user *shmaddr, int shmflg) 5325 { 5326 u32 perms; 5327 5328 if (shmflg & SHM_RDONLY) 5329 perms = SHM__READ; 5330 else 5331 perms = SHM__READ | SHM__WRITE; 5332 5333 return ipc_has_perm(&shp->shm_perm, perms); 5334 } 5335 5336 /* Semaphore security operations */ 5337 static int selinux_sem_alloc_security(struct sem_array *sma) 5338 { 5339 struct ipc_security_struct *isec; 5340 struct common_audit_data ad; 5341 u32 sid = current_sid(); 5342 int rc; 5343 5344 rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM); 5345 if (rc) 5346 return rc; 5347 5348 isec = sma->sem_perm.security; 5349 5350 ad.type = LSM_AUDIT_DATA_IPC; 5351 ad.u.ipc_id = sma->sem_perm.key; 5352 5353 rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM, 5354 SEM__CREATE, &ad); 5355 if (rc) { 5356 ipc_free_security(&sma->sem_perm); 5357 return rc; 5358 } 5359 return 0; 5360 } 5361 5362 static void selinux_sem_free_security(struct sem_array *sma) 5363 { 5364 ipc_free_security(&sma->sem_perm); 5365 } 5366 5367 static int selinux_sem_associate(struct sem_array *sma, int semflg) 5368 { 5369 struct ipc_security_struct *isec; 5370 struct common_audit_data ad; 5371 u32 sid = current_sid(); 5372 5373 isec = sma->sem_perm.security; 5374 5375 ad.type = LSM_AUDIT_DATA_IPC; 5376 ad.u.ipc_id = sma->sem_perm.key; 5377 5378 return avc_has_perm(sid, isec->sid, SECCLASS_SEM, 5379 SEM__ASSOCIATE, &ad); 5380 } 5381 5382 /* Note, at this point, sma is locked down */ 5383 static int selinux_sem_semctl(struct sem_array *sma, int cmd) 5384 { 5385 int err; 5386 u32 perms; 5387 5388 switch (cmd) { 5389 case IPC_INFO: 5390 case SEM_INFO: 5391 /* No specific object, just general system-wide information. */ 5392 return task_has_system(current, SYSTEM__IPC_INFO); 5393 case GETPID: 5394 case GETNCNT: 5395 case GETZCNT: 5396 perms = SEM__GETATTR; 5397 break; 5398 case GETVAL: 5399 case GETALL: 5400 perms = SEM__READ; 5401 break; 5402 case SETVAL: 5403 case SETALL: 5404 perms = SEM__WRITE; 5405 break; 5406 case IPC_RMID: 5407 perms = SEM__DESTROY; 5408 break; 5409 case IPC_SET: 5410 perms = SEM__SETATTR; 5411 break; 5412 case IPC_STAT: 5413 case SEM_STAT: 5414 perms = SEM__GETATTR | SEM__ASSOCIATE; 5415 break; 5416 default: 5417 return 0; 5418 } 5419 5420 err = ipc_has_perm(&sma->sem_perm, perms); 5421 return err; 5422 } 5423 5424 static int selinux_sem_semop(struct sem_array *sma, 5425 struct sembuf *sops, unsigned nsops, int alter) 5426 { 5427 u32 perms; 5428 5429 if (alter) 5430 perms = SEM__READ | SEM__WRITE; 5431 else 5432 perms = SEM__READ; 5433 5434 return ipc_has_perm(&sma->sem_perm, perms); 5435 } 5436 5437 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag) 5438 { 5439 u32 av = 0; 5440 5441 av = 0; 5442 if (flag & S_IRUGO) 5443 av |= IPC__UNIX_READ; 5444 if (flag & S_IWUGO) 5445 av |= IPC__UNIX_WRITE; 5446 5447 if (av == 0) 5448 return 0; 5449 5450 return ipc_has_perm(ipcp, av); 5451 } 5452 5453 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid) 5454 { 5455 struct ipc_security_struct *isec = ipcp->security; 5456 *secid = isec->sid; 5457 } 5458 5459 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode) 5460 { 5461 if (inode) 5462 inode_doinit_with_dentry(inode, dentry); 5463 } 5464 5465 static int selinux_getprocattr(struct task_struct *p, 5466 char *name, char **value) 5467 { 5468 const struct task_security_struct *__tsec; 5469 u32 sid; 5470 int error; 5471 unsigned len; 5472 5473 if (current != p) { 5474 error = current_has_perm(p, PROCESS__GETATTR); 5475 if (error) 5476 return error; 5477 } 5478 5479 rcu_read_lock(); 5480 __tsec = __task_cred(p)->security; 5481 5482 if (!strcmp(name, "current")) 5483 sid = __tsec->sid; 5484 else if (!strcmp(name, "prev")) 5485 sid = __tsec->osid; 5486 else if (!strcmp(name, "exec")) 5487 sid = __tsec->exec_sid; 5488 else if (!strcmp(name, "fscreate")) 5489 sid = __tsec->create_sid; 5490 else if (!strcmp(name, "keycreate")) 5491 sid = __tsec->keycreate_sid; 5492 else if (!strcmp(name, "sockcreate")) 5493 sid = __tsec->sockcreate_sid; 5494 else 5495 goto invalid; 5496 rcu_read_unlock(); 5497 5498 if (!sid) 5499 return 0; 5500 5501 error = security_sid_to_context(sid, value, &len); 5502 if (error) 5503 return error; 5504 return len; 5505 5506 invalid: 5507 rcu_read_unlock(); 5508 return -EINVAL; 5509 } 5510 5511 static int selinux_setprocattr(struct task_struct *p, 5512 char *name, void *value, size_t size) 5513 { 5514 struct task_security_struct *tsec; 5515 struct task_struct *tracer; 5516 struct cred *new; 5517 u32 sid = 0, ptsid; 5518 int error; 5519 char *str = value; 5520 5521 if (current != p) { 5522 /* SELinux only allows a process to change its own 5523 security attributes. */ 5524 return -EACCES; 5525 } 5526 5527 /* 5528 * Basic control over ability to set these attributes at all. 5529 * current == p, but we'll pass them separately in case the 5530 * above restriction is ever removed. 5531 */ 5532 if (!strcmp(name, "exec")) 5533 error = current_has_perm(p, PROCESS__SETEXEC); 5534 else if (!strcmp(name, "fscreate")) 5535 error = current_has_perm(p, PROCESS__SETFSCREATE); 5536 else if (!strcmp(name, "keycreate")) 5537 error = current_has_perm(p, PROCESS__SETKEYCREATE); 5538 else if (!strcmp(name, "sockcreate")) 5539 error = current_has_perm(p, PROCESS__SETSOCKCREATE); 5540 else if (!strcmp(name, "current")) 5541 error = current_has_perm(p, PROCESS__SETCURRENT); 5542 else 5543 error = -EINVAL; 5544 if (error) 5545 return error; 5546 5547 /* Obtain a SID for the context, if one was specified. */ 5548 if (size && str[1] && str[1] != '\n') { 5549 if (str[size-1] == '\n') { 5550 str[size-1] = 0; 5551 size--; 5552 } 5553 error = security_context_to_sid(value, size, &sid, GFP_KERNEL); 5554 if (error == -EINVAL && !strcmp(name, "fscreate")) { 5555 if (!capable(CAP_MAC_ADMIN)) { 5556 struct audit_buffer *ab; 5557 size_t audit_size; 5558 5559 /* We strip a nul only if it is at the end, otherwise the 5560 * context contains a nul and we should audit that */ 5561 if (str[size - 1] == '\0') 5562 audit_size = size - 1; 5563 else 5564 audit_size = size; 5565 ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR); 5566 audit_log_format(ab, "op=fscreate invalid_context="); 5567 audit_log_n_untrustedstring(ab, value, audit_size); 5568 audit_log_end(ab); 5569 5570 return error; 5571 } 5572 error = security_context_to_sid_force(value, size, 5573 &sid); 5574 } 5575 if (error) 5576 return error; 5577 } 5578 5579 new = prepare_creds(); 5580 if (!new) 5581 return -ENOMEM; 5582 5583 /* Permission checking based on the specified context is 5584 performed during the actual operation (execve, 5585 open/mkdir/...), when we know the full context of the 5586 operation. See selinux_bprm_set_creds for the execve 5587 checks and may_create for the file creation checks. The 5588 operation will then fail if the context is not permitted. */ 5589 tsec = new->security; 5590 if (!strcmp(name, "exec")) { 5591 tsec->exec_sid = sid; 5592 } else if (!strcmp(name, "fscreate")) { 5593 tsec->create_sid = sid; 5594 } else if (!strcmp(name, "keycreate")) { 5595 error = may_create_key(sid, p); 5596 if (error) 5597 goto abort_change; 5598 tsec->keycreate_sid = sid; 5599 } else if (!strcmp(name, "sockcreate")) { 5600 tsec->sockcreate_sid = sid; 5601 } else if (!strcmp(name, "current")) { 5602 error = -EINVAL; 5603 if (sid == 0) 5604 goto abort_change; 5605 5606 /* Only allow single threaded processes to change context */ 5607 error = -EPERM; 5608 if (!current_is_single_threaded()) { 5609 error = security_bounded_transition(tsec->sid, sid); 5610 if (error) 5611 goto abort_change; 5612 } 5613 5614 /* Check permissions for the transition. */ 5615 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS, 5616 PROCESS__DYNTRANSITION, NULL); 5617 if (error) 5618 goto abort_change; 5619 5620 /* Check for ptracing, and update the task SID if ok. 5621 Otherwise, leave SID unchanged and fail. */ 5622 ptsid = 0; 5623 rcu_read_lock(); 5624 tracer = ptrace_parent(p); 5625 if (tracer) 5626 ptsid = task_sid(tracer); 5627 rcu_read_unlock(); 5628 5629 if (tracer) { 5630 error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS, 5631 PROCESS__PTRACE, NULL); 5632 if (error) 5633 goto abort_change; 5634 } 5635 5636 tsec->sid = sid; 5637 } else { 5638 error = -EINVAL; 5639 goto abort_change; 5640 } 5641 5642 commit_creds(new); 5643 return size; 5644 5645 abort_change: 5646 abort_creds(new); 5647 return error; 5648 } 5649 5650 static int selinux_ismaclabel(const char *name) 5651 { 5652 return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0); 5653 } 5654 5655 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) 5656 { 5657 return security_sid_to_context(secid, secdata, seclen); 5658 } 5659 5660 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) 5661 { 5662 return security_context_to_sid(secdata, seclen, secid, GFP_KERNEL); 5663 } 5664 5665 static void selinux_release_secctx(char *secdata, u32 seclen) 5666 { 5667 kfree(secdata); 5668 } 5669 5670 /* 5671 * called with inode->i_mutex locked 5672 */ 5673 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen) 5674 { 5675 return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0); 5676 } 5677 5678 /* 5679 * called with inode->i_mutex locked 5680 */ 5681 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen) 5682 { 5683 return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0); 5684 } 5685 5686 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen) 5687 { 5688 int len = 0; 5689 len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX, 5690 ctx, true); 5691 if (len < 0) 5692 return len; 5693 *ctxlen = len; 5694 return 0; 5695 } 5696 #ifdef CONFIG_KEYS 5697 5698 static int selinux_key_alloc(struct key *k, const struct cred *cred, 5699 unsigned long flags) 5700 { 5701 const struct task_security_struct *tsec; 5702 struct key_security_struct *ksec; 5703 5704 ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL); 5705 if (!ksec) 5706 return -ENOMEM; 5707 5708 tsec = cred->security; 5709 if (tsec->keycreate_sid) 5710 ksec->sid = tsec->keycreate_sid; 5711 else 5712 ksec->sid = tsec->sid; 5713 5714 k->security = ksec; 5715 return 0; 5716 } 5717 5718 static void selinux_key_free(struct key *k) 5719 { 5720 struct key_security_struct *ksec = k->security; 5721 5722 k->security = NULL; 5723 kfree(ksec); 5724 } 5725 5726 static int selinux_key_permission(key_ref_t key_ref, 5727 const struct cred *cred, 5728 unsigned perm) 5729 { 5730 struct key *key; 5731 struct key_security_struct *ksec; 5732 u32 sid; 5733 5734 /* if no specific permissions are requested, we skip the 5735 permission check. No serious, additional covert channels 5736 appear to be created. */ 5737 if (perm == 0) 5738 return 0; 5739 5740 sid = cred_sid(cred); 5741 5742 key = key_ref_to_ptr(key_ref); 5743 ksec = key->security; 5744 5745 return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL); 5746 } 5747 5748 static int selinux_key_getsecurity(struct key *key, char **_buffer) 5749 { 5750 struct key_security_struct *ksec = key->security; 5751 char *context = NULL; 5752 unsigned len; 5753 int rc; 5754 5755 rc = security_sid_to_context(ksec->sid, &context, &len); 5756 if (!rc) 5757 rc = len; 5758 *_buffer = context; 5759 return rc; 5760 } 5761 5762 #endif 5763 5764 static struct security_operations selinux_ops = { 5765 .name = "selinux", 5766 5767 .ptrace_access_check = selinux_ptrace_access_check, 5768 .ptrace_traceme = selinux_ptrace_traceme, 5769 .capget = selinux_capget, 5770 .capset = selinux_capset, 5771 .capable = selinux_capable, 5772 .quotactl = selinux_quotactl, 5773 .quota_on = selinux_quota_on, 5774 .syslog = selinux_syslog, 5775 .vm_enough_memory = selinux_vm_enough_memory, 5776 5777 .netlink_send = selinux_netlink_send, 5778 5779 .bprm_set_creds = selinux_bprm_set_creds, 5780 .bprm_committing_creds = selinux_bprm_committing_creds, 5781 .bprm_committed_creds = selinux_bprm_committed_creds, 5782 .bprm_secureexec = selinux_bprm_secureexec, 5783 5784 .sb_alloc_security = selinux_sb_alloc_security, 5785 .sb_free_security = selinux_sb_free_security, 5786 .sb_copy_data = selinux_sb_copy_data, 5787 .sb_remount = selinux_sb_remount, 5788 .sb_kern_mount = selinux_sb_kern_mount, 5789 .sb_show_options = selinux_sb_show_options, 5790 .sb_statfs = selinux_sb_statfs, 5791 .sb_mount = selinux_mount, 5792 .sb_umount = selinux_umount, 5793 .sb_set_mnt_opts = selinux_set_mnt_opts, 5794 .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts, 5795 .sb_parse_opts_str = selinux_parse_opts_str, 5796 5797 .dentry_init_security = selinux_dentry_init_security, 5798 5799 .inode_alloc_security = selinux_inode_alloc_security, 5800 .inode_free_security = selinux_inode_free_security, 5801 .inode_init_security = selinux_inode_init_security, 5802 .inode_create = selinux_inode_create, 5803 .inode_link = selinux_inode_link, 5804 .inode_unlink = selinux_inode_unlink, 5805 .inode_symlink = selinux_inode_symlink, 5806 .inode_mkdir = selinux_inode_mkdir, 5807 .inode_rmdir = selinux_inode_rmdir, 5808 .inode_mknod = selinux_inode_mknod, 5809 .inode_rename = selinux_inode_rename, 5810 .inode_readlink = selinux_inode_readlink, 5811 .inode_follow_link = selinux_inode_follow_link, 5812 .inode_permission = selinux_inode_permission, 5813 .inode_setattr = selinux_inode_setattr, 5814 .inode_getattr = selinux_inode_getattr, 5815 .inode_setxattr = selinux_inode_setxattr, 5816 .inode_post_setxattr = selinux_inode_post_setxattr, 5817 .inode_getxattr = selinux_inode_getxattr, 5818 .inode_listxattr = selinux_inode_listxattr, 5819 .inode_removexattr = selinux_inode_removexattr, 5820 .inode_getsecurity = selinux_inode_getsecurity, 5821 .inode_setsecurity = selinux_inode_setsecurity, 5822 .inode_listsecurity = selinux_inode_listsecurity, 5823 .inode_getsecid = selinux_inode_getsecid, 5824 5825 .file_permission = selinux_file_permission, 5826 .file_alloc_security = selinux_file_alloc_security, 5827 .file_free_security = selinux_file_free_security, 5828 .file_ioctl = selinux_file_ioctl, 5829 .mmap_file = selinux_mmap_file, 5830 .mmap_addr = selinux_mmap_addr, 5831 .file_mprotect = selinux_file_mprotect, 5832 .file_lock = selinux_file_lock, 5833 .file_fcntl = selinux_file_fcntl, 5834 .file_set_fowner = selinux_file_set_fowner, 5835 .file_send_sigiotask = selinux_file_send_sigiotask, 5836 .file_receive = selinux_file_receive, 5837 5838 .file_open = selinux_file_open, 5839 5840 .task_create = selinux_task_create, 5841 .cred_alloc_blank = selinux_cred_alloc_blank, 5842 .cred_free = selinux_cred_free, 5843 .cred_prepare = selinux_cred_prepare, 5844 .cred_transfer = selinux_cred_transfer, 5845 .kernel_act_as = selinux_kernel_act_as, 5846 .kernel_create_files_as = selinux_kernel_create_files_as, 5847 .kernel_module_request = selinux_kernel_module_request, 5848 .task_setpgid = selinux_task_setpgid, 5849 .task_getpgid = selinux_task_getpgid, 5850 .task_getsid = selinux_task_getsid, 5851 .task_getsecid = selinux_task_getsecid, 5852 .task_setnice = selinux_task_setnice, 5853 .task_setioprio = selinux_task_setioprio, 5854 .task_getioprio = selinux_task_getioprio, 5855 .task_setrlimit = selinux_task_setrlimit, 5856 .task_setscheduler = selinux_task_setscheduler, 5857 .task_getscheduler = selinux_task_getscheduler, 5858 .task_movememory = selinux_task_movememory, 5859 .task_kill = selinux_task_kill, 5860 .task_wait = selinux_task_wait, 5861 .task_to_inode = selinux_task_to_inode, 5862 5863 .ipc_permission = selinux_ipc_permission, 5864 .ipc_getsecid = selinux_ipc_getsecid, 5865 5866 .msg_msg_alloc_security = selinux_msg_msg_alloc_security, 5867 .msg_msg_free_security = selinux_msg_msg_free_security, 5868 5869 .msg_queue_alloc_security = selinux_msg_queue_alloc_security, 5870 .msg_queue_free_security = selinux_msg_queue_free_security, 5871 .msg_queue_associate = selinux_msg_queue_associate, 5872 .msg_queue_msgctl = selinux_msg_queue_msgctl, 5873 .msg_queue_msgsnd = selinux_msg_queue_msgsnd, 5874 .msg_queue_msgrcv = selinux_msg_queue_msgrcv, 5875 5876 .shm_alloc_security = selinux_shm_alloc_security, 5877 .shm_free_security = selinux_shm_free_security, 5878 .shm_associate = selinux_shm_associate, 5879 .shm_shmctl = selinux_shm_shmctl, 5880 .shm_shmat = selinux_shm_shmat, 5881 5882 .sem_alloc_security = selinux_sem_alloc_security, 5883 .sem_free_security = selinux_sem_free_security, 5884 .sem_associate = selinux_sem_associate, 5885 .sem_semctl = selinux_sem_semctl, 5886 .sem_semop = selinux_sem_semop, 5887 5888 .d_instantiate = selinux_d_instantiate, 5889 5890 .getprocattr = selinux_getprocattr, 5891 .setprocattr = selinux_setprocattr, 5892 5893 .ismaclabel = selinux_ismaclabel, 5894 .secid_to_secctx = selinux_secid_to_secctx, 5895 .secctx_to_secid = selinux_secctx_to_secid, 5896 .release_secctx = selinux_release_secctx, 5897 .inode_notifysecctx = selinux_inode_notifysecctx, 5898 .inode_setsecctx = selinux_inode_setsecctx, 5899 .inode_getsecctx = selinux_inode_getsecctx, 5900 5901 .unix_stream_connect = selinux_socket_unix_stream_connect, 5902 .unix_may_send = selinux_socket_unix_may_send, 5903 5904 .socket_create = selinux_socket_create, 5905 .socket_post_create = selinux_socket_post_create, 5906 .socket_bind = selinux_socket_bind, 5907 .socket_connect = selinux_socket_connect, 5908 .socket_listen = selinux_socket_listen, 5909 .socket_accept = selinux_socket_accept, 5910 .socket_sendmsg = selinux_socket_sendmsg, 5911 .socket_recvmsg = selinux_socket_recvmsg, 5912 .socket_getsockname = selinux_socket_getsockname, 5913 .socket_getpeername = selinux_socket_getpeername, 5914 .socket_getsockopt = selinux_socket_getsockopt, 5915 .socket_setsockopt = selinux_socket_setsockopt, 5916 .socket_shutdown = selinux_socket_shutdown, 5917 .socket_sock_rcv_skb = selinux_socket_sock_rcv_skb, 5918 .socket_getpeersec_stream = selinux_socket_getpeersec_stream, 5919 .socket_getpeersec_dgram = selinux_socket_getpeersec_dgram, 5920 .sk_alloc_security = selinux_sk_alloc_security, 5921 .sk_free_security = selinux_sk_free_security, 5922 .sk_clone_security = selinux_sk_clone_security, 5923 .sk_getsecid = selinux_sk_getsecid, 5924 .sock_graft = selinux_sock_graft, 5925 .inet_conn_request = selinux_inet_conn_request, 5926 .inet_csk_clone = selinux_inet_csk_clone, 5927 .inet_conn_established = selinux_inet_conn_established, 5928 .secmark_relabel_packet = selinux_secmark_relabel_packet, 5929 .secmark_refcount_inc = selinux_secmark_refcount_inc, 5930 .secmark_refcount_dec = selinux_secmark_refcount_dec, 5931 .req_classify_flow = selinux_req_classify_flow, 5932 .tun_dev_alloc_security = selinux_tun_dev_alloc_security, 5933 .tun_dev_free_security = selinux_tun_dev_free_security, 5934 .tun_dev_create = selinux_tun_dev_create, 5935 .tun_dev_attach_queue = selinux_tun_dev_attach_queue, 5936 .tun_dev_attach = selinux_tun_dev_attach, 5937 .tun_dev_open = selinux_tun_dev_open, 5938 .skb_owned_by = selinux_skb_owned_by, 5939 5940 #ifdef CONFIG_SECURITY_NETWORK_XFRM 5941 .xfrm_policy_alloc_security = selinux_xfrm_policy_alloc, 5942 .xfrm_policy_clone_security = selinux_xfrm_policy_clone, 5943 .xfrm_policy_free_security = selinux_xfrm_policy_free, 5944 .xfrm_policy_delete_security = selinux_xfrm_policy_delete, 5945 .xfrm_state_alloc = selinux_xfrm_state_alloc, 5946 .xfrm_state_alloc_acquire = selinux_xfrm_state_alloc_acquire, 5947 .xfrm_state_free_security = selinux_xfrm_state_free, 5948 .xfrm_state_delete_security = selinux_xfrm_state_delete, 5949 .xfrm_policy_lookup = selinux_xfrm_policy_lookup, 5950 .xfrm_state_pol_flow_match = selinux_xfrm_state_pol_flow_match, 5951 .xfrm_decode_session = selinux_xfrm_decode_session, 5952 #endif 5953 5954 #ifdef CONFIG_KEYS 5955 .key_alloc = selinux_key_alloc, 5956 .key_free = selinux_key_free, 5957 .key_permission = selinux_key_permission, 5958 .key_getsecurity = selinux_key_getsecurity, 5959 #endif 5960 5961 #ifdef CONFIG_AUDIT 5962 .audit_rule_init = selinux_audit_rule_init, 5963 .audit_rule_known = selinux_audit_rule_known, 5964 .audit_rule_match = selinux_audit_rule_match, 5965 .audit_rule_free = selinux_audit_rule_free, 5966 #endif 5967 }; 5968 5969 static __init int selinux_init(void) 5970 { 5971 if (!security_module_enable(&selinux_ops)) { 5972 selinux_enabled = 0; 5973 return 0; 5974 } 5975 5976 if (!selinux_enabled) { 5977 printk(KERN_INFO "SELinux: Disabled at boot.\n"); 5978 return 0; 5979 } 5980 5981 printk(KERN_INFO "SELinux: Initializing.\n"); 5982 5983 /* Set the security state for the initial task. */ 5984 cred_init_security(); 5985 5986 default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC); 5987 5988 sel_inode_cache = kmem_cache_create("selinux_inode_security", 5989 sizeof(struct inode_security_struct), 5990 0, SLAB_PANIC, NULL); 5991 avc_init(); 5992 5993 if (register_security(&selinux_ops)) 5994 panic("SELinux: Unable to register with kernel.\n"); 5995 5996 if (selinux_enforcing) 5997 printk(KERN_DEBUG "SELinux: Starting in enforcing mode\n"); 5998 else 5999 printk(KERN_DEBUG "SELinux: Starting in permissive mode\n"); 6000 6001 return 0; 6002 } 6003 6004 static void delayed_superblock_init(struct super_block *sb, void *unused) 6005 { 6006 superblock_doinit(sb, NULL); 6007 } 6008 6009 void selinux_complete_init(void) 6010 { 6011 printk(KERN_DEBUG "SELinux: Completing initialization.\n"); 6012 6013 /* Set up any superblocks initialized prior to the policy load. */ 6014 printk(KERN_DEBUG "SELinux: Setting up existing superblocks.\n"); 6015 iterate_supers(delayed_superblock_init, NULL); 6016 } 6017 6018 /* SELinux requires early initialization in order to label 6019 all processes and objects when they are created. */ 6020 security_initcall(selinux_init); 6021 6022 #if defined(CONFIG_NETFILTER) 6023 6024 static struct nf_hook_ops selinux_ipv4_ops[] = { 6025 { 6026 .hook = selinux_ipv4_postroute, 6027 .owner = THIS_MODULE, 6028 .pf = NFPROTO_IPV4, 6029 .hooknum = NF_INET_POST_ROUTING, 6030 .priority = NF_IP_PRI_SELINUX_LAST, 6031 }, 6032 { 6033 .hook = selinux_ipv4_forward, 6034 .owner = THIS_MODULE, 6035 .pf = NFPROTO_IPV4, 6036 .hooknum = NF_INET_FORWARD, 6037 .priority = NF_IP_PRI_SELINUX_FIRST, 6038 }, 6039 { 6040 .hook = selinux_ipv4_output, 6041 .owner = THIS_MODULE, 6042 .pf = NFPROTO_IPV4, 6043 .hooknum = NF_INET_LOCAL_OUT, 6044 .priority = NF_IP_PRI_SELINUX_FIRST, 6045 } 6046 }; 6047 6048 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 6049 6050 static struct nf_hook_ops selinux_ipv6_ops[] = { 6051 { 6052 .hook = selinux_ipv6_postroute, 6053 .owner = THIS_MODULE, 6054 .pf = NFPROTO_IPV6, 6055 .hooknum = NF_INET_POST_ROUTING, 6056 .priority = NF_IP6_PRI_SELINUX_LAST, 6057 }, 6058 { 6059 .hook = selinux_ipv6_forward, 6060 .owner = THIS_MODULE, 6061 .pf = NFPROTO_IPV6, 6062 .hooknum = NF_INET_FORWARD, 6063 .priority = NF_IP6_PRI_SELINUX_FIRST, 6064 } 6065 }; 6066 6067 #endif /* IPV6 */ 6068 6069 static int __init selinux_nf_ip_init(void) 6070 { 6071 int err = 0; 6072 6073 if (!selinux_enabled) 6074 goto out; 6075 6076 printk(KERN_DEBUG "SELinux: Registering netfilter hooks\n"); 6077 6078 err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops)); 6079 if (err) 6080 panic("SELinux: nf_register_hooks for IPv4: error %d\n", err); 6081 6082 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 6083 err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops)); 6084 if (err) 6085 panic("SELinux: nf_register_hooks for IPv6: error %d\n", err); 6086 #endif /* IPV6 */ 6087 6088 out: 6089 return err; 6090 } 6091 6092 __initcall(selinux_nf_ip_init); 6093 6094 #ifdef CONFIG_SECURITY_SELINUX_DISABLE 6095 static void selinux_nf_ip_exit(void) 6096 { 6097 printk(KERN_DEBUG "SELinux: Unregistering netfilter hooks\n"); 6098 6099 nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops)); 6100 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) 6101 nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops)); 6102 #endif /* IPV6 */ 6103 } 6104 #endif 6105 6106 #else /* CONFIG_NETFILTER */ 6107 6108 #ifdef CONFIG_SECURITY_SELINUX_DISABLE 6109 #define selinux_nf_ip_exit() 6110 #endif 6111 6112 #endif /* CONFIG_NETFILTER */ 6113 6114 #ifdef CONFIG_SECURITY_SELINUX_DISABLE 6115 static int selinux_disabled; 6116 6117 int selinux_disable(void) 6118 { 6119 if (ss_initialized) { 6120 /* Not permitted after initial policy load. */ 6121 return -EINVAL; 6122 } 6123 6124 if (selinux_disabled) { 6125 /* Only do this once. */ 6126 return -EINVAL; 6127 } 6128 6129 printk(KERN_INFO "SELinux: Disabled at runtime.\n"); 6130 6131 selinux_disabled = 1; 6132 selinux_enabled = 0; 6133 6134 reset_security_ops(); 6135 6136 /* Try to destroy the avc node cache */ 6137 avc_disable(); 6138 6139 /* Unregister netfilter hooks. */ 6140 selinux_nf_ip_exit(); 6141 6142 /* Unregister selinuxfs. */ 6143 exit_sel_fs(); 6144 6145 return 0; 6146 } 6147 #endif 6148