1 /* 2 * Simplified MAC Kernel (smack) security module 3 * 4 * This file contains the smack hook function implementations. 5 * 6 * Author: 7 * Casey Schaufler <casey@schaufler-ca.com> 8 * 9 * Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com> 10 * Copyright (C) 2009 Hewlett-Packard Development Company, L.P. 11 * Paul Moore <paul.moore@hp.com> 12 * 13 * This program is free software; you can redistribute it and/or modify 14 * it under the terms of the GNU General Public License version 2, 15 * as published by the Free Software Foundation. 16 */ 17 18 #include <linux/xattr.h> 19 #include <linux/pagemap.h> 20 #include <linux/mount.h> 21 #include <linux/stat.h> 22 #include <linux/ext2_fs.h> 23 #include <linux/kd.h> 24 #include <asm/ioctls.h> 25 #include <linux/ip.h> 26 #include <linux/tcp.h> 27 #include <linux/udp.h> 28 #include <linux/mutex.h> 29 #include <linux/pipe_fs_i.h> 30 #include <net/netlabel.h> 31 #include <net/cipso_ipv4.h> 32 #include <linux/audit.h> 33 34 #include "smack.h" 35 36 #define task_security(task) (task_cred_xxx((task), security)) 37 38 /* 39 * I hope these are the hokeyist lines of code in the module. Casey. 40 */ 41 #define DEVPTS_SUPER_MAGIC 0x1cd1 42 #define SOCKFS_MAGIC 0x534F434B 43 #define TMPFS_MAGIC 0x01021994 44 45 /** 46 * smk_fetch - Fetch the smack label from a file. 47 * @ip: a pointer to the inode 48 * @dp: a pointer to the dentry 49 * 50 * Returns a pointer to the master list entry for the Smack label 51 * or NULL if there was no label to fetch. 52 */ 53 static char *smk_fetch(struct inode *ip, struct dentry *dp) 54 { 55 int rc; 56 char in[SMK_LABELLEN]; 57 58 if (ip->i_op->getxattr == NULL) 59 return NULL; 60 61 rc = ip->i_op->getxattr(dp, XATTR_NAME_SMACK, in, SMK_LABELLEN); 62 if (rc < 0) 63 return NULL; 64 65 return smk_import(in, rc); 66 } 67 68 /** 69 * new_inode_smack - allocate an inode security blob 70 * @smack: a pointer to the Smack label to use in the blob 71 * 72 * Returns the new blob or NULL if there's no memory available 73 */ 74 struct inode_smack *new_inode_smack(char *smack) 75 { 76 struct inode_smack *isp; 77 78 isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL); 79 if (isp == NULL) 80 return NULL; 81 82 isp->smk_inode = smack; 83 isp->smk_flags = 0; 84 mutex_init(&isp->smk_lock); 85 86 return isp; 87 } 88 89 /* 90 * LSM hooks. 91 * We he, that is fun! 92 */ 93 94 /** 95 * smack_ptrace_may_access - Smack approval on PTRACE_ATTACH 96 * @ctp: child task pointer 97 * @mode: ptrace attachment mode 98 * 99 * Returns 0 if access is OK, an error code otherwise 100 * 101 * Do the capability checks, and require read and write. 102 */ 103 static int smack_ptrace_may_access(struct task_struct *ctp, unsigned int mode) 104 { 105 int rc; 106 107 rc = cap_ptrace_may_access(ctp, mode); 108 if (rc != 0) 109 return rc; 110 111 rc = smk_access(current_security(), task_security(ctp), MAY_READWRITE); 112 if (rc != 0 && capable(CAP_MAC_OVERRIDE)) 113 return 0; 114 return rc; 115 } 116 117 /** 118 * smack_ptrace_traceme - Smack approval on PTRACE_TRACEME 119 * @ptp: parent task pointer 120 * 121 * Returns 0 if access is OK, an error code otherwise 122 * 123 * Do the capability checks, and require read and write. 124 */ 125 static int smack_ptrace_traceme(struct task_struct *ptp) 126 { 127 int rc; 128 129 rc = cap_ptrace_traceme(ptp); 130 if (rc != 0) 131 return rc; 132 133 rc = smk_access(task_security(ptp), current_security(), MAY_READWRITE); 134 if (rc != 0 && has_capability(ptp, CAP_MAC_OVERRIDE)) 135 return 0; 136 return rc; 137 } 138 139 /** 140 * smack_syslog - Smack approval on syslog 141 * @type: message type 142 * 143 * Require that the task has the floor label 144 * 145 * Returns 0 on success, error code otherwise. 146 */ 147 static int smack_syslog(int type) 148 { 149 int rc; 150 char *sp = current_security(); 151 152 rc = cap_syslog(type); 153 if (rc != 0) 154 return rc; 155 156 if (capable(CAP_MAC_OVERRIDE)) 157 return 0; 158 159 if (sp != smack_known_floor.smk_known) 160 rc = -EACCES; 161 162 return rc; 163 } 164 165 166 /* 167 * Superblock Hooks. 168 */ 169 170 /** 171 * smack_sb_alloc_security - allocate a superblock blob 172 * @sb: the superblock getting the blob 173 * 174 * Returns 0 on success or -ENOMEM on error. 175 */ 176 static int smack_sb_alloc_security(struct super_block *sb) 177 { 178 struct superblock_smack *sbsp; 179 180 sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL); 181 182 if (sbsp == NULL) 183 return -ENOMEM; 184 185 sbsp->smk_root = smack_known_floor.smk_known; 186 sbsp->smk_default = smack_known_floor.smk_known; 187 sbsp->smk_floor = smack_known_floor.smk_known; 188 sbsp->smk_hat = smack_known_hat.smk_known; 189 sbsp->smk_initialized = 0; 190 spin_lock_init(&sbsp->smk_sblock); 191 192 sb->s_security = sbsp; 193 194 return 0; 195 } 196 197 /** 198 * smack_sb_free_security - free a superblock blob 199 * @sb: the superblock getting the blob 200 * 201 */ 202 static void smack_sb_free_security(struct super_block *sb) 203 { 204 kfree(sb->s_security); 205 sb->s_security = NULL; 206 } 207 208 /** 209 * smack_sb_copy_data - copy mount options data for processing 210 * @orig: where to start 211 * @smackopts: mount options string 212 * 213 * Returns 0 on success or -ENOMEM on error. 214 * 215 * Copy the Smack specific mount options out of the mount 216 * options list. 217 */ 218 static int smack_sb_copy_data(char *orig, char *smackopts) 219 { 220 char *cp, *commap, *otheropts, *dp; 221 222 otheropts = (char *)get_zeroed_page(GFP_KERNEL); 223 if (otheropts == NULL) 224 return -ENOMEM; 225 226 for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) { 227 if (strstr(cp, SMK_FSDEFAULT) == cp) 228 dp = smackopts; 229 else if (strstr(cp, SMK_FSFLOOR) == cp) 230 dp = smackopts; 231 else if (strstr(cp, SMK_FSHAT) == cp) 232 dp = smackopts; 233 else if (strstr(cp, SMK_FSROOT) == cp) 234 dp = smackopts; 235 else 236 dp = otheropts; 237 238 commap = strchr(cp, ','); 239 if (commap != NULL) 240 *commap = '\0'; 241 242 if (*dp != '\0') 243 strcat(dp, ","); 244 strcat(dp, cp); 245 } 246 247 strcpy(orig, otheropts); 248 free_page((unsigned long)otheropts); 249 250 return 0; 251 } 252 253 /** 254 * smack_sb_kern_mount - Smack specific mount processing 255 * @sb: the file system superblock 256 * @flags: the mount flags 257 * @data: the smack mount options 258 * 259 * Returns 0 on success, an error code on failure 260 */ 261 static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data) 262 { 263 struct dentry *root = sb->s_root; 264 struct inode *inode = root->d_inode; 265 struct superblock_smack *sp = sb->s_security; 266 struct inode_smack *isp; 267 char *op; 268 char *commap; 269 char *nsp; 270 271 spin_lock(&sp->smk_sblock); 272 if (sp->smk_initialized != 0) { 273 spin_unlock(&sp->smk_sblock); 274 return 0; 275 } 276 sp->smk_initialized = 1; 277 spin_unlock(&sp->smk_sblock); 278 279 for (op = data; op != NULL; op = commap) { 280 commap = strchr(op, ','); 281 if (commap != NULL) 282 *commap++ = '\0'; 283 284 if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) { 285 op += strlen(SMK_FSHAT); 286 nsp = smk_import(op, 0); 287 if (nsp != NULL) 288 sp->smk_hat = nsp; 289 } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) { 290 op += strlen(SMK_FSFLOOR); 291 nsp = smk_import(op, 0); 292 if (nsp != NULL) 293 sp->smk_floor = nsp; 294 } else if (strncmp(op, SMK_FSDEFAULT, 295 strlen(SMK_FSDEFAULT)) == 0) { 296 op += strlen(SMK_FSDEFAULT); 297 nsp = smk_import(op, 0); 298 if (nsp != NULL) 299 sp->smk_default = nsp; 300 } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) { 301 op += strlen(SMK_FSROOT); 302 nsp = smk_import(op, 0); 303 if (nsp != NULL) 304 sp->smk_root = nsp; 305 } 306 } 307 308 /* 309 * Initialize the root inode. 310 */ 311 isp = inode->i_security; 312 if (isp == NULL) 313 inode->i_security = new_inode_smack(sp->smk_root); 314 else 315 isp->smk_inode = sp->smk_root; 316 317 return 0; 318 } 319 320 /** 321 * smack_sb_statfs - Smack check on statfs 322 * @dentry: identifies the file system in question 323 * 324 * Returns 0 if current can read the floor of the filesystem, 325 * and error code otherwise 326 */ 327 static int smack_sb_statfs(struct dentry *dentry) 328 { 329 struct superblock_smack *sbp = dentry->d_sb->s_security; 330 331 return smk_curacc(sbp->smk_floor, MAY_READ); 332 } 333 334 /** 335 * smack_sb_mount - Smack check for mounting 336 * @dev_name: unused 337 * @path: mount point 338 * @type: unused 339 * @flags: unused 340 * @data: unused 341 * 342 * Returns 0 if current can write the floor of the filesystem 343 * being mounted on, an error code otherwise. 344 */ 345 static int smack_sb_mount(char *dev_name, struct path *path, 346 char *type, unsigned long flags, void *data) 347 { 348 struct superblock_smack *sbp = path->mnt->mnt_sb->s_security; 349 350 return smk_curacc(sbp->smk_floor, MAY_WRITE); 351 } 352 353 /** 354 * smack_sb_umount - Smack check for unmounting 355 * @mnt: file system to unmount 356 * @flags: unused 357 * 358 * Returns 0 if current can write the floor of the filesystem 359 * being unmounted, an error code otherwise. 360 */ 361 static int smack_sb_umount(struct vfsmount *mnt, int flags) 362 { 363 struct superblock_smack *sbp; 364 365 sbp = mnt->mnt_sb->s_security; 366 367 return smk_curacc(sbp->smk_floor, MAY_WRITE); 368 } 369 370 /* 371 * Inode hooks 372 */ 373 374 /** 375 * smack_inode_alloc_security - allocate an inode blob 376 * @inode: the inode in need of a blob 377 * 378 * Returns 0 if it gets a blob, -ENOMEM otherwise 379 */ 380 static int smack_inode_alloc_security(struct inode *inode) 381 { 382 inode->i_security = new_inode_smack(current_security()); 383 if (inode->i_security == NULL) 384 return -ENOMEM; 385 return 0; 386 } 387 388 /** 389 * smack_inode_free_security - free an inode blob 390 * @inode: the inode with a blob 391 * 392 * Clears the blob pointer in inode 393 */ 394 static void smack_inode_free_security(struct inode *inode) 395 { 396 kfree(inode->i_security); 397 inode->i_security = NULL; 398 } 399 400 /** 401 * smack_inode_init_security - copy out the smack from an inode 402 * @inode: the inode 403 * @dir: unused 404 * @name: where to put the attribute name 405 * @value: where to put the attribute value 406 * @len: where to put the length of the attribute 407 * 408 * Returns 0 if it all works out, -ENOMEM if there's no memory 409 */ 410 static int smack_inode_init_security(struct inode *inode, struct inode *dir, 411 char **name, void **value, size_t *len) 412 { 413 char *isp = smk_of_inode(inode); 414 415 if (name) { 416 *name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL); 417 if (*name == NULL) 418 return -ENOMEM; 419 } 420 421 if (value) { 422 *value = kstrdup(isp, GFP_KERNEL); 423 if (*value == NULL) 424 return -ENOMEM; 425 } 426 427 if (len) 428 *len = strlen(isp) + 1; 429 430 return 0; 431 } 432 433 /** 434 * smack_inode_link - Smack check on link 435 * @old_dentry: the existing object 436 * @dir: unused 437 * @new_dentry: the new object 438 * 439 * Returns 0 if access is permitted, an error code otherwise 440 */ 441 static int smack_inode_link(struct dentry *old_dentry, struct inode *dir, 442 struct dentry *new_dentry) 443 { 444 int rc; 445 char *isp; 446 447 isp = smk_of_inode(old_dentry->d_inode); 448 rc = smk_curacc(isp, MAY_WRITE); 449 450 if (rc == 0 && new_dentry->d_inode != NULL) { 451 isp = smk_of_inode(new_dentry->d_inode); 452 rc = smk_curacc(isp, MAY_WRITE); 453 } 454 455 return rc; 456 } 457 458 /** 459 * smack_inode_unlink - Smack check on inode deletion 460 * @dir: containing directory object 461 * @dentry: file to unlink 462 * 463 * Returns 0 if current can write the containing directory 464 * and the object, error code otherwise 465 */ 466 static int smack_inode_unlink(struct inode *dir, struct dentry *dentry) 467 { 468 struct inode *ip = dentry->d_inode; 469 int rc; 470 471 /* 472 * You need write access to the thing you're unlinking 473 */ 474 rc = smk_curacc(smk_of_inode(ip), MAY_WRITE); 475 if (rc == 0) 476 /* 477 * You also need write access to the containing directory 478 */ 479 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE); 480 481 return rc; 482 } 483 484 /** 485 * smack_inode_rmdir - Smack check on directory deletion 486 * @dir: containing directory object 487 * @dentry: directory to unlink 488 * 489 * Returns 0 if current can write the containing directory 490 * and the directory, error code otherwise 491 */ 492 static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry) 493 { 494 int rc; 495 496 /* 497 * You need write access to the thing you're removing 498 */ 499 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); 500 if (rc == 0) 501 /* 502 * You also need write access to the containing directory 503 */ 504 rc = smk_curacc(smk_of_inode(dir), MAY_WRITE); 505 506 return rc; 507 } 508 509 /** 510 * smack_inode_rename - Smack check on rename 511 * @old_inode: the old directory 512 * @old_dentry: unused 513 * @new_inode: the new directory 514 * @new_dentry: unused 515 * 516 * Read and write access is required on both the old and 517 * new directories. 518 * 519 * Returns 0 if access is permitted, an error code otherwise 520 */ 521 static int smack_inode_rename(struct inode *old_inode, 522 struct dentry *old_dentry, 523 struct inode *new_inode, 524 struct dentry *new_dentry) 525 { 526 int rc; 527 char *isp; 528 529 isp = smk_of_inode(old_dentry->d_inode); 530 rc = smk_curacc(isp, MAY_READWRITE); 531 532 if (rc == 0 && new_dentry->d_inode != NULL) { 533 isp = smk_of_inode(new_dentry->d_inode); 534 rc = smk_curacc(isp, MAY_READWRITE); 535 } 536 537 return rc; 538 } 539 540 /** 541 * smack_inode_permission - Smack version of permission() 542 * @inode: the inode in question 543 * @mask: the access requested 544 * 545 * This is the important Smack hook. 546 * 547 * Returns 0 if access is permitted, -EACCES otherwise 548 */ 549 static int smack_inode_permission(struct inode *inode, int mask) 550 { 551 /* 552 * No permission to check. Existence test. Yup, it's there. 553 */ 554 if (mask == 0) 555 return 0; 556 557 return smk_curacc(smk_of_inode(inode), mask); 558 } 559 560 /** 561 * smack_inode_setattr - Smack check for setting attributes 562 * @dentry: the object 563 * @iattr: for the force flag 564 * 565 * Returns 0 if access is permitted, an error code otherwise 566 */ 567 static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr) 568 { 569 /* 570 * Need to allow for clearing the setuid bit. 571 */ 572 if (iattr->ia_valid & ATTR_FORCE) 573 return 0; 574 575 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); 576 } 577 578 /** 579 * smack_inode_getattr - Smack check for getting attributes 580 * @mnt: unused 581 * @dentry: the object 582 * 583 * Returns 0 if access is permitted, an error code otherwise 584 */ 585 static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry) 586 { 587 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ); 588 } 589 590 /** 591 * smack_inode_setxattr - Smack check for setting xattrs 592 * @dentry: the object 593 * @name: name of the attribute 594 * @value: unused 595 * @size: unused 596 * @flags: unused 597 * 598 * This protects the Smack attribute explicitly. 599 * 600 * Returns 0 if access is permitted, an error code otherwise 601 */ 602 static int smack_inode_setxattr(struct dentry *dentry, const char *name, 603 const void *value, size_t size, int flags) 604 { 605 int rc = 0; 606 607 if (strcmp(name, XATTR_NAME_SMACK) == 0 || 608 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || 609 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) { 610 if (!capable(CAP_MAC_ADMIN)) 611 rc = -EPERM; 612 /* 613 * check label validity here so import wont fail on 614 * post_setxattr 615 */ 616 if (size == 0 || size >= SMK_LABELLEN || 617 smk_import(value, size) == NULL) 618 rc = -EINVAL; 619 } else 620 rc = cap_inode_setxattr(dentry, name, value, size, flags); 621 622 if (rc == 0) 623 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); 624 625 return rc; 626 } 627 628 /** 629 * smack_inode_post_setxattr - Apply the Smack update approved above 630 * @dentry: object 631 * @name: attribute name 632 * @value: attribute value 633 * @size: attribute size 634 * @flags: unused 635 * 636 * Set the pointer in the inode blob to the entry found 637 * in the master label list. 638 */ 639 static void smack_inode_post_setxattr(struct dentry *dentry, const char *name, 640 const void *value, size_t size, int flags) 641 { 642 struct inode_smack *isp; 643 char *nsp; 644 645 /* 646 * Not SMACK 647 */ 648 if (strcmp(name, XATTR_NAME_SMACK)) 649 return; 650 651 isp = dentry->d_inode->i_security; 652 653 /* 654 * No locking is done here. This is a pointer 655 * assignment. 656 */ 657 nsp = smk_import(value, size); 658 if (nsp != NULL) 659 isp->smk_inode = nsp; 660 else 661 isp->smk_inode = smack_known_invalid.smk_known; 662 663 return; 664 } 665 666 /* 667 * smack_inode_getxattr - Smack check on getxattr 668 * @dentry: the object 669 * @name: unused 670 * 671 * Returns 0 if access is permitted, an error code otherwise 672 */ 673 static int smack_inode_getxattr(struct dentry *dentry, const char *name) 674 { 675 return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ); 676 } 677 678 /* 679 * smack_inode_removexattr - Smack check on removexattr 680 * @dentry: the object 681 * @name: name of the attribute 682 * 683 * Removing the Smack attribute requires CAP_MAC_ADMIN 684 * 685 * Returns 0 if access is permitted, an error code otherwise 686 */ 687 static int smack_inode_removexattr(struct dentry *dentry, const char *name) 688 { 689 int rc = 0; 690 691 if (strcmp(name, XATTR_NAME_SMACK) == 0 || 692 strcmp(name, XATTR_NAME_SMACKIPIN) == 0 || 693 strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) { 694 if (!capable(CAP_MAC_ADMIN)) 695 rc = -EPERM; 696 } else 697 rc = cap_inode_removexattr(dentry, name); 698 699 if (rc == 0) 700 rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE); 701 702 return rc; 703 } 704 705 /** 706 * smack_inode_getsecurity - get smack xattrs 707 * @inode: the object 708 * @name: attribute name 709 * @buffer: where to put the result 710 * @alloc: unused 711 * 712 * Returns the size of the attribute or an error code 713 */ 714 static int smack_inode_getsecurity(const struct inode *inode, 715 const char *name, void **buffer, 716 bool alloc) 717 { 718 struct socket_smack *ssp; 719 struct socket *sock; 720 struct super_block *sbp; 721 struct inode *ip = (struct inode *)inode; 722 char *isp; 723 int ilen; 724 int rc = 0; 725 726 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { 727 isp = smk_of_inode(inode); 728 ilen = strlen(isp) + 1; 729 *buffer = isp; 730 return ilen; 731 } 732 733 /* 734 * The rest of the Smack xattrs are only on sockets. 735 */ 736 sbp = ip->i_sb; 737 if (sbp->s_magic != SOCKFS_MAGIC) 738 return -EOPNOTSUPP; 739 740 sock = SOCKET_I(ip); 741 if (sock == NULL || sock->sk == NULL) 742 return -EOPNOTSUPP; 743 744 ssp = sock->sk->sk_security; 745 746 if (strcmp(name, XATTR_SMACK_IPIN) == 0) 747 isp = ssp->smk_in; 748 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) 749 isp = ssp->smk_out; 750 else 751 return -EOPNOTSUPP; 752 753 ilen = strlen(isp) + 1; 754 if (rc == 0) { 755 *buffer = isp; 756 rc = ilen; 757 } 758 759 return rc; 760 } 761 762 763 /** 764 * smack_inode_listsecurity - list the Smack attributes 765 * @inode: the object 766 * @buffer: where they go 767 * @buffer_size: size of buffer 768 * 769 * Returns 0 on success, -EINVAL otherwise 770 */ 771 static int smack_inode_listsecurity(struct inode *inode, char *buffer, 772 size_t buffer_size) 773 { 774 int len = strlen(XATTR_NAME_SMACK); 775 776 if (buffer != NULL && len <= buffer_size) { 777 memcpy(buffer, XATTR_NAME_SMACK, len); 778 return len; 779 } 780 return -EINVAL; 781 } 782 783 /** 784 * smack_inode_getsecid - Extract inode's security id 785 * @inode: inode to extract the info from 786 * @secid: where result will be saved 787 */ 788 static void smack_inode_getsecid(const struct inode *inode, u32 *secid) 789 { 790 struct inode_smack *isp = inode->i_security; 791 792 *secid = smack_to_secid(isp->smk_inode); 793 } 794 795 /* 796 * File Hooks 797 */ 798 799 /** 800 * smack_file_permission - Smack check on file operations 801 * @file: unused 802 * @mask: unused 803 * 804 * Returns 0 805 * 806 * Should access checks be done on each read or write? 807 * UNICOS and SELinux say yes. 808 * Trusted Solaris, Trusted Irix, and just about everyone else says no. 809 * 810 * I'll say no for now. Smack does not do the frequent 811 * label changing that SELinux does. 812 */ 813 static int smack_file_permission(struct file *file, int mask) 814 { 815 return 0; 816 } 817 818 /** 819 * smack_file_alloc_security - assign a file security blob 820 * @file: the object 821 * 822 * The security blob for a file is a pointer to the master 823 * label list, so no allocation is done. 824 * 825 * Returns 0 826 */ 827 static int smack_file_alloc_security(struct file *file) 828 { 829 file->f_security = current_security(); 830 return 0; 831 } 832 833 /** 834 * smack_file_free_security - clear a file security blob 835 * @file: the object 836 * 837 * The security blob for a file is a pointer to the master 838 * label list, so no memory is freed. 839 */ 840 static void smack_file_free_security(struct file *file) 841 { 842 file->f_security = NULL; 843 } 844 845 /** 846 * smack_file_ioctl - Smack check on ioctls 847 * @file: the object 848 * @cmd: what to do 849 * @arg: unused 850 * 851 * Relies heavily on the correct use of the ioctl command conventions. 852 * 853 * Returns 0 if allowed, error code otherwise 854 */ 855 static int smack_file_ioctl(struct file *file, unsigned int cmd, 856 unsigned long arg) 857 { 858 int rc = 0; 859 860 if (_IOC_DIR(cmd) & _IOC_WRITE) 861 rc = smk_curacc(file->f_security, MAY_WRITE); 862 863 if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ)) 864 rc = smk_curacc(file->f_security, MAY_READ); 865 866 return rc; 867 } 868 869 /** 870 * smack_file_lock - Smack check on file locking 871 * @file: the object 872 * @cmd: unused 873 * 874 * Returns 0 if current has write access, error code otherwise 875 */ 876 static int smack_file_lock(struct file *file, unsigned int cmd) 877 { 878 return smk_curacc(file->f_security, MAY_WRITE); 879 } 880 881 /** 882 * smack_file_fcntl - Smack check on fcntl 883 * @file: the object 884 * @cmd: what action to check 885 * @arg: unused 886 * 887 * Returns 0 if current has access, error code otherwise 888 */ 889 static int smack_file_fcntl(struct file *file, unsigned int cmd, 890 unsigned long arg) 891 { 892 int rc; 893 894 switch (cmd) { 895 case F_DUPFD: 896 case F_GETFD: 897 case F_GETFL: 898 case F_GETLK: 899 case F_GETOWN: 900 case F_GETSIG: 901 rc = smk_curacc(file->f_security, MAY_READ); 902 break; 903 case F_SETFD: 904 case F_SETFL: 905 case F_SETLK: 906 case F_SETLKW: 907 case F_SETOWN: 908 case F_SETSIG: 909 rc = smk_curacc(file->f_security, MAY_WRITE); 910 break; 911 default: 912 rc = smk_curacc(file->f_security, MAY_READWRITE); 913 } 914 915 return rc; 916 } 917 918 /** 919 * smack_file_set_fowner - set the file security blob value 920 * @file: object in question 921 * 922 * Returns 0 923 * Further research may be required on this one. 924 */ 925 static int smack_file_set_fowner(struct file *file) 926 { 927 file->f_security = current_security(); 928 return 0; 929 } 930 931 /** 932 * smack_file_send_sigiotask - Smack on sigio 933 * @tsk: The target task 934 * @fown: the object the signal come from 935 * @signum: unused 936 * 937 * Allow a privileged task to get signals even if it shouldn't 938 * 939 * Returns 0 if a subject with the object's smack could 940 * write to the task, an error code otherwise. 941 */ 942 static int smack_file_send_sigiotask(struct task_struct *tsk, 943 struct fown_struct *fown, int signum) 944 { 945 struct file *file; 946 int rc; 947 948 /* 949 * struct fown_struct is never outside the context of a struct file 950 */ 951 file = container_of(fown, struct file, f_owner); 952 rc = smk_access(file->f_security, tsk->cred->security, MAY_WRITE); 953 if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE)) 954 return 0; 955 return rc; 956 } 957 958 /** 959 * smack_file_receive - Smack file receive check 960 * @file: the object 961 * 962 * Returns 0 if current has access, error code otherwise 963 */ 964 static int smack_file_receive(struct file *file) 965 { 966 int may = 0; 967 968 /* 969 * This code relies on bitmasks. 970 */ 971 if (file->f_mode & FMODE_READ) 972 may = MAY_READ; 973 if (file->f_mode & FMODE_WRITE) 974 may |= MAY_WRITE; 975 976 return smk_curacc(file->f_security, may); 977 } 978 979 /* 980 * Task hooks 981 */ 982 983 /** 984 * smack_cred_free - "free" task-level security credentials 985 * @cred: the credentials in question 986 * 987 * Smack isn't using copies of blobs. Everyone 988 * points to an immutable list. The blobs never go away. 989 * There is no leak here. 990 */ 991 static void smack_cred_free(struct cred *cred) 992 { 993 cred->security = NULL; 994 } 995 996 /** 997 * smack_cred_prepare - prepare new set of credentials for modification 998 * @new: the new credentials 999 * @old: the original credentials 1000 * @gfp: the atomicity of any memory allocations 1001 * 1002 * Prepare a new set of credentials for modification. 1003 */ 1004 static int smack_cred_prepare(struct cred *new, const struct cred *old, 1005 gfp_t gfp) 1006 { 1007 new->security = old->security; 1008 return 0; 1009 } 1010 1011 /** 1012 * smack_cred_commit - commit new credentials 1013 * @new: the new credentials 1014 * @old: the original credentials 1015 */ 1016 static void smack_cred_commit(struct cred *new, const struct cred *old) 1017 { 1018 } 1019 1020 /** 1021 * smack_kernel_act_as - Set the subjective context in a set of credentials 1022 * @new: points to the set of credentials to be modified. 1023 * @secid: specifies the security ID to be set 1024 * 1025 * Set the security data for a kernel service. 1026 */ 1027 static int smack_kernel_act_as(struct cred *new, u32 secid) 1028 { 1029 char *smack = smack_from_secid(secid); 1030 1031 if (smack == NULL) 1032 return -EINVAL; 1033 1034 new->security = smack; 1035 return 0; 1036 } 1037 1038 /** 1039 * smack_kernel_create_files_as - Set the file creation label in a set of creds 1040 * @new: points to the set of credentials to be modified 1041 * @inode: points to the inode to use as a reference 1042 * 1043 * Set the file creation context in a set of credentials to the same 1044 * as the objective context of the specified inode 1045 */ 1046 static int smack_kernel_create_files_as(struct cred *new, 1047 struct inode *inode) 1048 { 1049 struct inode_smack *isp = inode->i_security; 1050 1051 new->security = isp->smk_inode; 1052 return 0; 1053 } 1054 1055 /** 1056 * smack_task_setpgid - Smack check on setting pgid 1057 * @p: the task object 1058 * @pgid: unused 1059 * 1060 * Return 0 if write access is permitted 1061 */ 1062 static int smack_task_setpgid(struct task_struct *p, pid_t pgid) 1063 { 1064 return smk_curacc(task_security(p), MAY_WRITE); 1065 } 1066 1067 /** 1068 * smack_task_getpgid - Smack access check for getpgid 1069 * @p: the object task 1070 * 1071 * Returns 0 if current can read the object task, error code otherwise 1072 */ 1073 static int smack_task_getpgid(struct task_struct *p) 1074 { 1075 return smk_curacc(task_security(p), MAY_READ); 1076 } 1077 1078 /** 1079 * smack_task_getsid - Smack access check for getsid 1080 * @p: the object task 1081 * 1082 * Returns 0 if current can read the object task, error code otherwise 1083 */ 1084 static int smack_task_getsid(struct task_struct *p) 1085 { 1086 return smk_curacc(task_security(p), MAY_READ); 1087 } 1088 1089 /** 1090 * smack_task_getsecid - get the secid of the task 1091 * @p: the object task 1092 * @secid: where to put the result 1093 * 1094 * Sets the secid to contain a u32 version of the smack label. 1095 */ 1096 static void smack_task_getsecid(struct task_struct *p, u32 *secid) 1097 { 1098 *secid = smack_to_secid(task_security(p)); 1099 } 1100 1101 /** 1102 * smack_task_setnice - Smack check on setting nice 1103 * @p: the task object 1104 * @nice: unused 1105 * 1106 * Return 0 if write access is permitted 1107 */ 1108 static int smack_task_setnice(struct task_struct *p, int nice) 1109 { 1110 int rc; 1111 1112 rc = cap_task_setnice(p, nice); 1113 if (rc == 0) 1114 rc = smk_curacc(task_security(p), MAY_WRITE); 1115 return rc; 1116 } 1117 1118 /** 1119 * smack_task_setioprio - Smack check on setting ioprio 1120 * @p: the task object 1121 * @ioprio: unused 1122 * 1123 * Return 0 if write access is permitted 1124 */ 1125 static int smack_task_setioprio(struct task_struct *p, int ioprio) 1126 { 1127 int rc; 1128 1129 rc = cap_task_setioprio(p, ioprio); 1130 if (rc == 0) 1131 rc = smk_curacc(task_security(p), MAY_WRITE); 1132 return rc; 1133 } 1134 1135 /** 1136 * smack_task_getioprio - Smack check on reading ioprio 1137 * @p: the task object 1138 * 1139 * Return 0 if read access is permitted 1140 */ 1141 static int smack_task_getioprio(struct task_struct *p) 1142 { 1143 return smk_curacc(task_security(p), MAY_READ); 1144 } 1145 1146 /** 1147 * smack_task_setscheduler - Smack check on setting scheduler 1148 * @p: the task object 1149 * @policy: unused 1150 * @lp: unused 1151 * 1152 * Return 0 if read access is permitted 1153 */ 1154 static int smack_task_setscheduler(struct task_struct *p, int policy, 1155 struct sched_param *lp) 1156 { 1157 int rc; 1158 1159 rc = cap_task_setscheduler(p, policy, lp); 1160 if (rc == 0) 1161 rc = smk_curacc(task_security(p), MAY_WRITE); 1162 return rc; 1163 } 1164 1165 /** 1166 * smack_task_getscheduler - Smack check on reading scheduler 1167 * @p: the task object 1168 * 1169 * Return 0 if read access is permitted 1170 */ 1171 static int smack_task_getscheduler(struct task_struct *p) 1172 { 1173 return smk_curacc(task_security(p), MAY_READ); 1174 } 1175 1176 /** 1177 * smack_task_movememory - Smack check on moving memory 1178 * @p: the task object 1179 * 1180 * Return 0 if write access is permitted 1181 */ 1182 static int smack_task_movememory(struct task_struct *p) 1183 { 1184 return smk_curacc(task_security(p), MAY_WRITE); 1185 } 1186 1187 /** 1188 * smack_task_kill - Smack check on signal delivery 1189 * @p: the task object 1190 * @info: unused 1191 * @sig: unused 1192 * @secid: identifies the smack to use in lieu of current's 1193 * 1194 * Return 0 if write access is permitted 1195 * 1196 * The secid behavior is an artifact of an SELinux hack 1197 * in the USB code. Someday it may go away. 1198 */ 1199 static int smack_task_kill(struct task_struct *p, struct siginfo *info, 1200 int sig, u32 secid) 1201 { 1202 /* 1203 * Sending a signal requires that the sender 1204 * can write the receiver. 1205 */ 1206 if (secid == 0) 1207 return smk_curacc(task_security(p), MAY_WRITE); 1208 /* 1209 * If the secid isn't 0 we're dealing with some USB IO 1210 * specific behavior. This is not clean. For one thing 1211 * we can't take privilege into account. 1212 */ 1213 return smk_access(smack_from_secid(secid), task_security(p), MAY_WRITE); 1214 } 1215 1216 /** 1217 * smack_task_wait - Smack access check for waiting 1218 * @p: task to wait for 1219 * 1220 * Returns 0 if current can wait for p, error code otherwise 1221 */ 1222 static int smack_task_wait(struct task_struct *p) 1223 { 1224 int rc; 1225 1226 rc = smk_access(current_security(), task_security(p), MAY_WRITE); 1227 if (rc == 0) 1228 return 0; 1229 1230 /* 1231 * Allow the operation to succeed if either task 1232 * has privilege to perform operations that might 1233 * account for the smack labels having gotten to 1234 * be different in the first place. 1235 * 1236 * This breaks the strict subject/object access 1237 * control ideal, taking the object's privilege 1238 * state into account in the decision as well as 1239 * the smack value. 1240 */ 1241 if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE)) 1242 return 0; 1243 1244 return rc; 1245 } 1246 1247 /** 1248 * smack_task_to_inode - copy task smack into the inode blob 1249 * @p: task to copy from 1250 * @inode: inode to copy to 1251 * 1252 * Sets the smack pointer in the inode security blob 1253 */ 1254 static void smack_task_to_inode(struct task_struct *p, struct inode *inode) 1255 { 1256 struct inode_smack *isp = inode->i_security; 1257 isp->smk_inode = task_security(p); 1258 } 1259 1260 /* 1261 * Socket hooks. 1262 */ 1263 1264 /** 1265 * smack_sk_alloc_security - Allocate a socket blob 1266 * @sk: the socket 1267 * @family: unused 1268 * @gfp_flags: memory allocation flags 1269 * 1270 * Assign Smack pointers to current 1271 * 1272 * Returns 0 on success, -ENOMEM is there's no memory 1273 */ 1274 static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags) 1275 { 1276 char *csp = current_security(); 1277 struct socket_smack *ssp; 1278 1279 ssp = kzalloc(sizeof(struct socket_smack), gfp_flags); 1280 if (ssp == NULL) 1281 return -ENOMEM; 1282 1283 ssp->smk_in = csp; 1284 ssp->smk_out = csp; 1285 ssp->smk_packet[0] = '\0'; 1286 1287 sk->sk_security = ssp; 1288 1289 return 0; 1290 } 1291 1292 /** 1293 * smack_sk_free_security - Free a socket blob 1294 * @sk: the socket 1295 * 1296 * Clears the blob pointer 1297 */ 1298 static void smack_sk_free_security(struct sock *sk) 1299 { 1300 kfree(sk->sk_security); 1301 } 1302 1303 /** 1304 * smack_host_label - check host based restrictions 1305 * @sip: the object end 1306 * 1307 * looks for host based access restrictions 1308 * 1309 * This version will only be appropriate for really small sets of single label 1310 * hosts. The caller is responsible for ensuring that the RCU read lock is 1311 * taken before calling this function. 1312 * 1313 * Returns the label of the far end or NULL if it's not special. 1314 */ 1315 static char *smack_host_label(struct sockaddr_in *sip) 1316 { 1317 struct smk_netlbladdr *snp; 1318 struct in_addr *siap = &sip->sin_addr; 1319 1320 if (siap->s_addr == 0) 1321 return NULL; 1322 1323 list_for_each_entry_rcu(snp, &smk_netlbladdr_list, list) 1324 /* 1325 * we break after finding the first match because 1326 * the list is sorted from longest to shortest mask 1327 * so we have found the most specific match 1328 */ 1329 if ((&snp->smk_host.sin_addr)->s_addr == 1330 (siap->s_addr & (&snp->smk_mask)->s_addr)) { 1331 /* we have found the special CIPSO option */ 1332 if (snp->smk_label == smack_cipso_option) 1333 return NULL; 1334 return snp->smk_label; 1335 } 1336 1337 return NULL; 1338 } 1339 1340 /** 1341 * smack_set_catset - convert a capset to netlabel mls categories 1342 * @catset: the Smack categories 1343 * @sap: where to put the netlabel categories 1344 * 1345 * Allocates and fills attr.mls.cat 1346 */ 1347 static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap) 1348 { 1349 unsigned char *cp; 1350 unsigned char m; 1351 int cat; 1352 int rc; 1353 int byte; 1354 1355 if (!catset) 1356 return; 1357 1358 sap->flags |= NETLBL_SECATTR_MLS_CAT; 1359 sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC); 1360 sap->attr.mls.cat->startbit = 0; 1361 1362 for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++) 1363 for (m = 0x80; m != 0; m >>= 1, cat++) { 1364 if ((m & *cp) == 0) 1365 continue; 1366 rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat, 1367 cat, GFP_ATOMIC); 1368 } 1369 } 1370 1371 /** 1372 * smack_to_secattr - fill a secattr from a smack value 1373 * @smack: the smack value 1374 * @nlsp: where the result goes 1375 * 1376 * Casey says that CIPSO is good enough for now. 1377 * It can be used to effect. 1378 * It can also be abused to effect when necessary. 1379 * Appologies to the TSIG group in general and GW in particular. 1380 */ 1381 static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp) 1382 { 1383 struct smack_cipso cipso; 1384 int rc; 1385 1386 nlsp->domain = smack; 1387 nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL; 1388 1389 rc = smack_to_cipso(smack, &cipso); 1390 if (rc == 0) { 1391 nlsp->attr.mls.lvl = cipso.smk_level; 1392 smack_set_catset(cipso.smk_catset, nlsp); 1393 } else { 1394 nlsp->attr.mls.lvl = smack_cipso_direct; 1395 smack_set_catset(smack, nlsp); 1396 } 1397 } 1398 1399 /** 1400 * smack_netlabel - Set the secattr on a socket 1401 * @sk: the socket 1402 * @labeled: socket label scheme 1403 * 1404 * Convert the outbound smack value (smk_out) to a 1405 * secattr and attach it to the socket. 1406 * 1407 * Returns 0 on success or an error code 1408 */ 1409 static int smack_netlabel(struct sock *sk, int labeled) 1410 { 1411 struct socket_smack *ssp = sk->sk_security; 1412 struct netlbl_lsm_secattr secattr; 1413 int rc = 0; 1414 1415 /* 1416 * Usually the netlabel code will handle changing the 1417 * packet labeling based on the label. 1418 * The case of a single label host is different, because 1419 * a single label host should never get a labeled packet 1420 * even though the label is usually associated with a packet 1421 * label. 1422 */ 1423 local_bh_disable(); 1424 bh_lock_sock_nested(sk); 1425 1426 if (ssp->smk_out == smack_net_ambient || 1427 labeled == SMACK_UNLABELED_SOCKET) 1428 netlbl_sock_delattr(sk); 1429 else { 1430 netlbl_secattr_init(&secattr); 1431 smack_to_secattr(ssp->smk_out, &secattr); 1432 rc = netlbl_sock_setattr(sk, sk->sk_family, &secattr); 1433 netlbl_secattr_destroy(&secattr); 1434 } 1435 1436 bh_unlock_sock(sk); 1437 local_bh_enable(); 1438 1439 return rc; 1440 } 1441 1442 /** 1443 * smack_netlbel_send - Set the secattr on a socket and perform access checks 1444 * @sk: the socket 1445 * @sap: the destination address 1446 * 1447 * Set the correct secattr for the given socket based on the destination 1448 * address and perform any outbound access checks needed. 1449 * 1450 * Returns 0 on success or an error code. 1451 * 1452 */ 1453 static int smack_netlabel_send(struct sock *sk, struct sockaddr_in *sap) 1454 { 1455 int rc; 1456 int sk_lbl; 1457 char *hostsp; 1458 struct socket_smack *ssp = sk->sk_security; 1459 1460 rcu_read_lock(); 1461 hostsp = smack_host_label(sap); 1462 if (hostsp != NULL) { 1463 sk_lbl = SMACK_UNLABELED_SOCKET; 1464 rc = smk_access(ssp->smk_out, hostsp, MAY_WRITE); 1465 } else { 1466 sk_lbl = SMACK_CIPSO_SOCKET; 1467 rc = 0; 1468 } 1469 rcu_read_unlock(); 1470 if (rc != 0) 1471 return rc; 1472 1473 return smack_netlabel(sk, sk_lbl); 1474 } 1475 1476 /** 1477 * smack_inode_setsecurity - set smack xattrs 1478 * @inode: the object 1479 * @name: attribute name 1480 * @value: attribute value 1481 * @size: size of the attribute 1482 * @flags: unused 1483 * 1484 * Sets the named attribute in the appropriate blob 1485 * 1486 * Returns 0 on success, or an error code 1487 */ 1488 static int smack_inode_setsecurity(struct inode *inode, const char *name, 1489 const void *value, size_t size, int flags) 1490 { 1491 char *sp; 1492 struct inode_smack *nsp = inode->i_security; 1493 struct socket_smack *ssp; 1494 struct socket *sock; 1495 int rc = 0; 1496 1497 if (value == NULL || size > SMK_LABELLEN || size == 0) 1498 return -EACCES; 1499 1500 sp = smk_import(value, size); 1501 if (sp == NULL) 1502 return -EINVAL; 1503 1504 if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) { 1505 nsp->smk_inode = sp; 1506 return 0; 1507 } 1508 /* 1509 * The rest of the Smack xattrs are only on sockets. 1510 */ 1511 if (inode->i_sb->s_magic != SOCKFS_MAGIC) 1512 return -EOPNOTSUPP; 1513 1514 sock = SOCKET_I(inode); 1515 if (sock == NULL || sock->sk == NULL) 1516 return -EOPNOTSUPP; 1517 1518 ssp = sock->sk->sk_security; 1519 1520 if (strcmp(name, XATTR_SMACK_IPIN) == 0) 1521 ssp->smk_in = sp; 1522 else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) { 1523 ssp->smk_out = sp; 1524 rc = smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); 1525 if (rc != 0) 1526 printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n", 1527 __func__, -rc); 1528 } else 1529 return -EOPNOTSUPP; 1530 1531 return 0; 1532 } 1533 1534 /** 1535 * smack_socket_post_create - finish socket setup 1536 * @sock: the socket 1537 * @family: protocol family 1538 * @type: unused 1539 * @protocol: unused 1540 * @kern: unused 1541 * 1542 * Sets the netlabel information on the socket 1543 * 1544 * Returns 0 on success, and error code otherwise 1545 */ 1546 static int smack_socket_post_create(struct socket *sock, int family, 1547 int type, int protocol, int kern) 1548 { 1549 if (family != PF_INET || sock->sk == NULL) 1550 return 0; 1551 /* 1552 * Set the outbound netlbl. 1553 */ 1554 return smack_netlabel(sock->sk, SMACK_CIPSO_SOCKET); 1555 } 1556 1557 /** 1558 * smack_socket_connect - connect access check 1559 * @sock: the socket 1560 * @sap: the other end 1561 * @addrlen: size of sap 1562 * 1563 * Verifies that a connection may be possible 1564 * 1565 * Returns 0 on success, and error code otherwise 1566 */ 1567 static int smack_socket_connect(struct socket *sock, struct sockaddr *sap, 1568 int addrlen) 1569 { 1570 if (sock->sk == NULL || sock->sk->sk_family != PF_INET) 1571 return 0; 1572 if (addrlen < sizeof(struct sockaddr_in)) 1573 return -EINVAL; 1574 1575 return smack_netlabel_send(sock->sk, (struct sockaddr_in *)sap); 1576 } 1577 1578 /** 1579 * smack_flags_to_may - convert S_ to MAY_ values 1580 * @flags: the S_ value 1581 * 1582 * Returns the equivalent MAY_ value 1583 */ 1584 static int smack_flags_to_may(int flags) 1585 { 1586 int may = 0; 1587 1588 if (flags & S_IRUGO) 1589 may |= MAY_READ; 1590 if (flags & S_IWUGO) 1591 may |= MAY_WRITE; 1592 if (flags & S_IXUGO) 1593 may |= MAY_EXEC; 1594 1595 return may; 1596 } 1597 1598 /** 1599 * smack_msg_msg_alloc_security - Set the security blob for msg_msg 1600 * @msg: the object 1601 * 1602 * Returns 0 1603 */ 1604 static int smack_msg_msg_alloc_security(struct msg_msg *msg) 1605 { 1606 msg->security = current_security(); 1607 return 0; 1608 } 1609 1610 /** 1611 * smack_msg_msg_free_security - Clear the security blob for msg_msg 1612 * @msg: the object 1613 * 1614 * Clears the blob pointer 1615 */ 1616 static void smack_msg_msg_free_security(struct msg_msg *msg) 1617 { 1618 msg->security = NULL; 1619 } 1620 1621 /** 1622 * smack_of_shm - the smack pointer for the shm 1623 * @shp: the object 1624 * 1625 * Returns a pointer to the smack value 1626 */ 1627 static char *smack_of_shm(struct shmid_kernel *shp) 1628 { 1629 return (char *)shp->shm_perm.security; 1630 } 1631 1632 /** 1633 * smack_shm_alloc_security - Set the security blob for shm 1634 * @shp: the object 1635 * 1636 * Returns 0 1637 */ 1638 static int smack_shm_alloc_security(struct shmid_kernel *shp) 1639 { 1640 struct kern_ipc_perm *isp = &shp->shm_perm; 1641 1642 isp->security = current_security(); 1643 return 0; 1644 } 1645 1646 /** 1647 * smack_shm_free_security - Clear the security blob for shm 1648 * @shp: the object 1649 * 1650 * Clears the blob pointer 1651 */ 1652 static void smack_shm_free_security(struct shmid_kernel *shp) 1653 { 1654 struct kern_ipc_perm *isp = &shp->shm_perm; 1655 1656 isp->security = NULL; 1657 } 1658 1659 /** 1660 * smack_shm_associate - Smack access check for shm 1661 * @shp: the object 1662 * @shmflg: access requested 1663 * 1664 * Returns 0 if current has the requested access, error code otherwise 1665 */ 1666 static int smack_shm_associate(struct shmid_kernel *shp, int shmflg) 1667 { 1668 char *ssp = smack_of_shm(shp); 1669 int may; 1670 1671 may = smack_flags_to_may(shmflg); 1672 return smk_curacc(ssp, may); 1673 } 1674 1675 /** 1676 * smack_shm_shmctl - Smack access check for shm 1677 * @shp: the object 1678 * @cmd: what it wants to do 1679 * 1680 * Returns 0 if current has the requested access, error code otherwise 1681 */ 1682 static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd) 1683 { 1684 char *ssp; 1685 int may; 1686 1687 switch (cmd) { 1688 case IPC_STAT: 1689 case SHM_STAT: 1690 may = MAY_READ; 1691 break; 1692 case IPC_SET: 1693 case SHM_LOCK: 1694 case SHM_UNLOCK: 1695 case IPC_RMID: 1696 may = MAY_READWRITE; 1697 break; 1698 case IPC_INFO: 1699 case SHM_INFO: 1700 /* 1701 * System level information. 1702 */ 1703 return 0; 1704 default: 1705 return -EINVAL; 1706 } 1707 1708 ssp = smack_of_shm(shp); 1709 return smk_curacc(ssp, may); 1710 } 1711 1712 /** 1713 * smack_shm_shmat - Smack access for shmat 1714 * @shp: the object 1715 * @shmaddr: unused 1716 * @shmflg: access requested 1717 * 1718 * Returns 0 if current has the requested access, error code otherwise 1719 */ 1720 static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr, 1721 int shmflg) 1722 { 1723 char *ssp = smack_of_shm(shp); 1724 int may; 1725 1726 may = smack_flags_to_may(shmflg); 1727 return smk_curacc(ssp, may); 1728 } 1729 1730 /** 1731 * smack_of_sem - the smack pointer for the sem 1732 * @sma: the object 1733 * 1734 * Returns a pointer to the smack value 1735 */ 1736 static char *smack_of_sem(struct sem_array *sma) 1737 { 1738 return (char *)sma->sem_perm.security; 1739 } 1740 1741 /** 1742 * smack_sem_alloc_security - Set the security blob for sem 1743 * @sma: the object 1744 * 1745 * Returns 0 1746 */ 1747 static int smack_sem_alloc_security(struct sem_array *sma) 1748 { 1749 struct kern_ipc_perm *isp = &sma->sem_perm; 1750 1751 isp->security = current_security(); 1752 return 0; 1753 } 1754 1755 /** 1756 * smack_sem_free_security - Clear the security blob for sem 1757 * @sma: the object 1758 * 1759 * Clears the blob pointer 1760 */ 1761 static void smack_sem_free_security(struct sem_array *sma) 1762 { 1763 struct kern_ipc_perm *isp = &sma->sem_perm; 1764 1765 isp->security = NULL; 1766 } 1767 1768 /** 1769 * smack_sem_associate - Smack access check for sem 1770 * @sma: the object 1771 * @semflg: access requested 1772 * 1773 * Returns 0 if current has the requested access, error code otherwise 1774 */ 1775 static int smack_sem_associate(struct sem_array *sma, int semflg) 1776 { 1777 char *ssp = smack_of_sem(sma); 1778 int may; 1779 1780 may = smack_flags_to_may(semflg); 1781 return smk_curacc(ssp, may); 1782 } 1783 1784 /** 1785 * smack_sem_shmctl - Smack access check for sem 1786 * @sma: the object 1787 * @cmd: what it wants to do 1788 * 1789 * Returns 0 if current has the requested access, error code otherwise 1790 */ 1791 static int smack_sem_semctl(struct sem_array *sma, int cmd) 1792 { 1793 char *ssp; 1794 int may; 1795 1796 switch (cmd) { 1797 case GETPID: 1798 case GETNCNT: 1799 case GETZCNT: 1800 case GETVAL: 1801 case GETALL: 1802 case IPC_STAT: 1803 case SEM_STAT: 1804 may = MAY_READ; 1805 break; 1806 case SETVAL: 1807 case SETALL: 1808 case IPC_RMID: 1809 case IPC_SET: 1810 may = MAY_READWRITE; 1811 break; 1812 case IPC_INFO: 1813 case SEM_INFO: 1814 /* 1815 * System level information 1816 */ 1817 return 0; 1818 default: 1819 return -EINVAL; 1820 } 1821 1822 ssp = smack_of_sem(sma); 1823 return smk_curacc(ssp, may); 1824 } 1825 1826 /** 1827 * smack_sem_semop - Smack checks of semaphore operations 1828 * @sma: the object 1829 * @sops: unused 1830 * @nsops: unused 1831 * @alter: unused 1832 * 1833 * Treated as read and write in all cases. 1834 * 1835 * Returns 0 if access is allowed, error code otherwise 1836 */ 1837 static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops, 1838 unsigned nsops, int alter) 1839 { 1840 char *ssp = smack_of_sem(sma); 1841 1842 return smk_curacc(ssp, MAY_READWRITE); 1843 } 1844 1845 /** 1846 * smack_msg_alloc_security - Set the security blob for msg 1847 * @msq: the object 1848 * 1849 * Returns 0 1850 */ 1851 static int smack_msg_queue_alloc_security(struct msg_queue *msq) 1852 { 1853 struct kern_ipc_perm *kisp = &msq->q_perm; 1854 1855 kisp->security = current_security(); 1856 return 0; 1857 } 1858 1859 /** 1860 * smack_msg_free_security - Clear the security blob for msg 1861 * @msq: the object 1862 * 1863 * Clears the blob pointer 1864 */ 1865 static void smack_msg_queue_free_security(struct msg_queue *msq) 1866 { 1867 struct kern_ipc_perm *kisp = &msq->q_perm; 1868 1869 kisp->security = NULL; 1870 } 1871 1872 /** 1873 * smack_of_msq - the smack pointer for the msq 1874 * @msq: the object 1875 * 1876 * Returns a pointer to the smack value 1877 */ 1878 static char *smack_of_msq(struct msg_queue *msq) 1879 { 1880 return (char *)msq->q_perm.security; 1881 } 1882 1883 /** 1884 * smack_msg_queue_associate - Smack access check for msg_queue 1885 * @msq: the object 1886 * @msqflg: access requested 1887 * 1888 * Returns 0 if current has the requested access, error code otherwise 1889 */ 1890 static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg) 1891 { 1892 char *msp = smack_of_msq(msq); 1893 int may; 1894 1895 may = smack_flags_to_may(msqflg); 1896 return smk_curacc(msp, may); 1897 } 1898 1899 /** 1900 * smack_msg_queue_msgctl - Smack access check for msg_queue 1901 * @msq: the object 1902 * @cmd: what it wants to do 1903 * 1904 * Returns 0 if current has the requested access, error code otherwise 1905 */ 1906 static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd) 1907 { 1908 char *msp; 1909 int may; 1910 1911 switch (cmd) { 1912 case IPC_STAT: 1913 case MSG_STAT: 1914 may = MAY_READ; 1915 break; 1916 case IPC_SET: 1917 case IPC_RMID: 1918 may = MAY_READWRITE; 1919 break; 1920 case IPC_INFO: 1921 case MSG_INFO: 1922 /* 1923 * System level information 1924 */ 1925 return 0; 1926 default: 1927 return -EINVAL; 1928 } 1929 1930 msp = smack_of_msq(msq); 1931 return smk_curacc(msp, may); 1932 } 1933 1934 /** 1935 * smack_msg_queue_msgsnd - Smack access check for msg_queue 1936 * @msq: the object 1937 * @msg: unused 1938 * @msqflg: access requested 1939 * 1940 * Returns 0 if current has the requested access, error code otherwise 1941 */ 1942 static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, 1943 int msqflg) 1944 { 1945 char *msp = smack_of_msq(msq); 1946 int rc; 1947 1948 rc = smack_flags_to_may(msqflg); 1949 return smk_curacc(msp, rc); 1950 } 1951 1952 /** 1953 * smack_msg_queue_msgsnd - Smack access check for msg_queue 1954 * @msq: the object 1955 * @msg: unused 1956 * @target: unused 1957 * @type: unused 1958 * @mode: unused 1959 * 1960 * Returns 0 if current has read and write access, error code otherwise 1961 */ 1962 static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg, 1963 struct task_struct *target, long type, int mode) 1964 { 1965 char *msp = smack_of_msq(msq); 1966 1967 return smk_curacc(msp, MAY_READWRITE); 1968 } 1969 1970 /** 1971 * smack_ipc_permission - Smack access for ipc_permission() 1972 * @ipp: the object permissions 1973 * @flag: access requested 1974 * 1975 * Returns 0 if current has read and write access, error code otherwise 1976 */ 1977 static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag) 1978 { 1979 char *isp = ipp->security; 1980 int may; 1981 1982 may = smack_flags_to_may(flag); 1983 return smk_curacc(isp, may); 1984 } 1985 1986 /** 1987 * smack_ipc_getsecid - Extract smack security id 1988 * @ipp: the object permissions 1989 * @secid: where result will be saved 1990 */ 1991 static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid) 1992 { 1993 char *smack = ipp->security; 1994 1995 *secid = smack_to_secid(smack); 1996 } 1997 1998 /** 1999 * smack_d_instantiate - Make sure the blob is correct on an inode 2000 * @opt_dentry: unused 2001 * @inode: the object 2002 * 2003 * Set the inode's security blob if it hasn't been done already. 2004 */ 2005 static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode) 2006 { 2007 struct super_block *sbp; 2008 struct superblock_smack *sbsp; 2009 struct inode_smack *isp; 2010 char *csp = current_security(); 2011 char *fetched; 2012 char *final; 2013 struct dentry *dp; 2014 2015 if (inode == NULL) 2016 return; 2017 2018 isp = inode->i_security; 2019 2020 mutex_lock(&isp->smk_lock); 2021 /* 2022 * If the inode is already instantiated 2023 * take the quick way out 2024 */ 2025 if (isp->smk_flags & SMK_INODE_INSTANT) 2026 goto unlockandout; 2027 2028 sbp = inode->i_sb; 2029 sbsp = sbp->s_security; 2030 /* 2031 * We're going to use the superblock default label 2032 * if there's no label on the file. 2033 */ 2034 final = sbsp->smk_default; 2035 2036 /* 2037 * If this is the root inode the superblock 2038 * may be in the process of initialization. 2039 * If that is the case use the root value out 2040 * of the superblock. 2041 */ 2042 if (opt_dentry->d_parent == opt_dentry) { 2043 isp->smk_inode = sbsp->smk_root; 2044 isp->smk_flags |= SMK_INODE_INSTANT; 2045 goto unlockandout; 2046 } 2047 2048 /* 2049 * This is pretty hackish. 2050 * Casey says that we shouldn't have to do 2051 * file system specific code, but it does help 2052 * with keeping it simple. 2053 */ 2054 switch (sbp->s_magic) { 2055 case SMACK_MAGIC: 2056 /* 2057 * Casey says that it's a little embarassing 2058 * that the smack file system doesn't do 2059 * extended attributes. 2060 */ 2061 final = smack_known_star.smk_known; 2062 break; 2063 case PIPEFS_MAGIC: 2064 /* 2065 * Casey says pipes are easy (?) 2066 */ 2067 final = smack_known_star.smk_known; 2068 break; 2069 case DEVPTS_SUPER_MAGIC: 2070 /* 2071 * devpts seems content with the label of the task. 2072 * Programs that change smack have to treat the 2073 * pty with respect. 2074 */ 2075 final = csp; 2076 break; 2077 case SOCKFS_MAGIC: 2078 /* 2079 * Casey says sockets get the smack of the task. 2080 */ 2081 final = csp; 2082 break; 2083 case PROC_SUPER_MAGIC: 2084 /* 2085 * Casey says procfs appears not to care. 2086 * The superblock default suffices. 2087 */ 2088 break; 2089 case TMPFS_MAGIC: 2090 /* 2091 * Device labels should come from the filesystem, 2092 * but watch out, because they're volitile, 2093 * getting recreated on every reboot. 2094 */ 2095 final = smack_known_star.smk_known; 2096 /* 2097 * No break. 2098 * 2099 * If a smack value has been set we want to use it, 2100 * but since tmpfs isn't giving us the opportunity 2101 * to set mount options simulate setting the 2102 * superblock default. 2103 */ 2104 default: 2105 /* 2106 * This isn't an understood special case. 2107 * Get the value from the xattr. 2108 * 2109 * No xattr support means, alas, no SMACK label. 2110 * Use the aforeapplied default. 2111 * It would be curious if the label of the task 2112 * does not match that assigned. 2113 */ 2114 if (inode->i_op->getxattr == NULL) 2115 break; 2116 /* 2117 * Get the dentry for xattr. 2118 */ 2119 if (opt_dentry == NULL) { 2120 dp = d_find_alias(inode); 2121 if (dp == NULL) 2122 break; 2123 } else { 2124 dp = dget(opt_dentry); 2125 if (dp == NULL) 2126 break; 2127 } 2128 2129 fetched = smk_fetch(inode, dp); 2130 if (fetched != NULL) 2131 final = fetched; 2132 2133 dput(dp); 2134 break; 2135 } 2136 2137 if (final == NULL) 2138 isp->smk_inode = csp; 2139 else 2140 isp->smk_inode = final; 2141 2142 isp->smk_flags |= SMK_INODE_INSTANT; 2143 2144 unlockandout: 2145 mutex_unlock(&isp->smk_lock); 2146 return; 2147 } 2148 2149 /** 2150 * smack_getprocattr - Smack process attribute access 2151 * @p: the object task 2152 * @name: the name of the attribute in /proc/.../attr 2153 * @value: where to put the result 2154 * 2155 * Places a copy of the task Smack into value 2156 * 2157 * Returns the length of the smack label or an error code 2158 */ 2159 static int smack_getprocattr(struct task_struct *p, char *name, char **value) 2160 { 2161 char *cp; 2162 int slen; 2163 2164 if (strcmp(name, "current") != 0) 2165 return -EINVAL; 2166 2167 cp = kstrdup(task_security(p), GFP_KERNEL); 2168 if (cp == NULL) 2169 return -ENOMEM; 2170 2171 slen = strlen(cp); 2172 *value = cp; 2173 return slen; 2174 } 2175 2176 /** 2177 * smack_setprocattr - Smack process attribute setting 2178 * @p: the object task 2179 * @name: the name of the attribute in /proc/.../attr 2180 * @value: the value to set 2181 * @size: the size of the value 2182 * 2183 * Sets the Smack value of the task. Only setting self 2184 * is permitted and only with privilege 2185 * 2186 * Returns the length of the smack label or an error code 2187 */ 2188 static int smack_setprocattr(struct task_struct *p, char *name, 2189 void *value, size_t size) 2190 { 2191 struct cred *new; 2192 char *newsmack; 2193 2194 /* 2195 * Changing another process' Smack value is too dangerous 2196 * and supports no sane use case. 2197 */ 2198 if (p != current) 2199 return -EPERM; 2200 2201 if (!capable(CAP_MAC_ADMIN)) 2202 return -EPERM; 2203 2204 if (value == NULL || size == 0 || size >= SMK_LABELLEN) 2205 return -EINVAL; 2206 2207 if (strcmp(name, "current") != 0) 2208 return -EINVAL; 2209 2210 newsmack = smk_import(value, size); 2211 if (newsmack == NULL) 2212 return -EINVAL; 2213 2214 /* 2215 * No process is ever allowed the web ("@") label. 2216 */ 2217 if (newsmack == smack_known_web.smk_known) 2218 return -EPERM; 2219 2220 new = prepare_creds(); 2221 if (new == NULL) 2222 return -ENOMEM; 2223 new->security = newsmack; 2224 commit_creds(new); 2225 return size; 2226 } 2227 2228 /** 2229 * smack_unix_stream_connect - Smack access on UDS 2230 * @sock: one socket 2231 * @other: the other socket 2232 * @newsk: unused 2233 * 2234 * Return 0 if a subject with the smack of sock could access 2235 * an object with the smack of other, otherwise an error code 2236 */ 2237 static int smack_unix_stream_connect(struct socket *sock, 2238 struct socket *other, struct sock *newsk) 2239 { 2240 struct inode *sp = SOCK_INODE(sock); 2241 struct inode *op = SOCK_INODE(other); 2242 2243 return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_READWRITE); 2244 } 2245 2246 /** 2247 * smack_unix_may_send - Smack access on UDS 2248 * @sock: one socket 2249 * @other: the other socket 2250 * 2251 * Return 0 if a subject with the smack of sock could access 2252 * an object with the smack of other, otherwise an error code 2253 */ 2254 static int smack_unix_may_send(struct socket *sock, struct socket *other) 2255 { 2256 struct inode *sp = SOCK_INODE(sock); 2257 struct inode *op = SOCK_INODE(other); 2258 2259 return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_WRITE); 2260 } 2261 2262 /** 2263 * smack_socket_sendmsg - Smack check based on destination host 2264 * @sock: the socket 2265 * @msg: the message 2266 * @size: the size of the message 2267 * 2268 * Return 0 if the current subject can write to the destination 2269 * host. This is only a question if the destination is a single 2270 * label host. 2271 */ 2272 static int smack_socket_sendmsg(struct socket *sock, struct msghdr *msg, 2273 int size) 2274 { 2275 struct sockaddr_in *sip = (struct sockaddr_in *) msg->msg_name; 2276 2277 /* 2278 * Perfectly reasonable for this to be NULL 2279 */ 2280 if (sip == NULL || sip->sin_family != PF_INET) 2281 return 0; 2282 2283 return smack_netlabel_send(sock->sk, sip); 2284 } 2285 2286 2287 /** 2288 * smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat pair to smack 2289 * @sap: netlabel secattr 2290 * @sip: where to put the result 2291 * 2292 * Copies a smack label into sip 2293 */ 2294 static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip) 2295 { 2296 char smack[SMK_LABELLEN]; 2297 char *sp; 2298 int pcat; 2299 2300 if ((sap->flags & NETLBL_SECATTR_MLS_LVL) != 0) { 2301 /* 2302 * Looks like a CIPSO packet. 2303 * If there are flags but no level netlabel isn't 2304 * behaving the way we expect it to. 2305 * 2306 * Get the categories, if any 2307 * Without guidance regarding the smack value 2308 * for the packet fall back on the network 2309 * ambient value. 2310 */ 2311 memset(smack, '\0', SMK_LABELLEN); 2312 if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0) 2313 for (pcat = -1;;) { 2314 pcat = netlbl_secattr_catmap_walk( 2315 sap->attr.mls.cat, pcat + 1); 2316 if (pcat < 0) 2317 break; 2318 smack_catset_bit(pcat, smack); 2319 } 2320 /* 2321 * If it is CIPSO using smack direct mapping 2322 * we are already done. WeeHee. 2323 */ 2324 if (sap->attr.mls.lvl == smack_cipso_direct) { 2325 memcpy(sip, smack, SMK_MAXLEN); 2326 return; 2327 } 2328 /* 2329 * Look it up in the supplied table if it is not 2330 * a direct mapping. 2331 */ 2332 smack_from_cipso(sap->attr.mls.lvl, smack, sip); 2333 return; 2334 } 2335 if ((sap->flags & NETLBL_SECATTR_SECID) != 0) { 2336 /* 2337 * Looks like a fallback, which gives us a secid. 2338 */ 2339 sp = smack_from_secid(sap->attr.secid); 2340 /* 2341 * This has got to be a bug because it is 2342 * impossible to specify a fallback without 2343 * specifying the label, which will ensure 2344 * it has a secid, and the only way to get a 2345 * secid is from a fallback. 2346 */ 2347 BUG_ON(sp == NULL); 2348 strncpy(sip, sp, SMK_MAXLEN); 2349 return; 2350 } 2351 /* 2352 * Without guidance regarding the smack value 2353 * for the packet fall back on the network 2354 * ambient value. 2355 */ 2356 strncpy(sip, smack_net_ambient, SMK_MAXLEN); 2357 return; 2358 } 2359 2360 /** 2361 * smack_socket_sock_rcv_skb - Smack packet delivery access check 2362 * @sk: socket 2363 * @skb: packet 2364 * 2365 * Returns 0 if the packet should be delivered, an error code otherwise 2366 */ 2367 static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb) 2368 { 2369 struct netlbl_lsm_secattr secattr; 2370 struct socket_smack *ssp = sk->sk_security; 2371 char smack[SMK_LABELLEN]; 2372 char *csp; 2373 int rc; 2374 2375 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) 2376 return 0; 2377 2378 /* 2379 * Translate what netlabel gave us. 2380 */ 2381 netlbl_secattr_init(&secattr); 2382 2383 rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr); 2384 if (rc == 0) { 2385 smack_from_secattr(&secattr, smack); 2386 csp = smack; 2387 } else 2388 csp = smack_net_ambient; 2389 2390 netlbl_secattr_destroy(&secattr); 2391 2392 /* 2393 * Receiving a packet requires that the other end 2394 * be able to write here. Read access is not required. 2395 * This is the simplist possible security model 2396 * for networking. 2397 */ 2398 rc = smk_access(csp, ssp->smk_in, MAY_WRITE); 2399 if (rc != 0) 2400 netlbl_skbuff_err(skb, rc, 0); 2401 return rc; 2402 } 2403 2404 /** 2405 * smack_socket_getpeersec_stream - pull in packet label 2406 * @sock: the socket 2407 * @optval: user's destination 2408 * @optlen: size thereof 2409 * @len: max thereof 2410 * 2411 * returns zero on success, an error code otherwise 2412 */ 2413 static int smack_socket_getpeersec_stream(struct socket *sock, 2414 char __user *optval, 2415 int __user *optlen, unsigned len) 2416 { 2417 struct socket_smack *ssp; 2418 int slen; 2419 int rc = 0; 2420 2421 ssp = sock->sk->sk_security; 2422 slen = strlen(ssp->smk_packet) + 1; 2423 2424 if (slen > len) 2425 rc = -ERANGE; 2426 else if (copy_to_user(optval, ssp->smk_packet, slen) != 0) 2427 rc = -EFAULT; 2428 2429 if (put_user(slen, optlen) != 0) 2430 rc = -EFAULT; 2431 2432 return rc; 2433 } 2434 2435 2436 /** 2437 * smack_socket_getpeersec_dgram - pull in packet label 2438 * @sock: the socket 2439 * @skb: packet data 2440 * @secid: pointer to where to put the secid of the packet 2441 * 2442 * Sets the netlabel socket state on sk from parent 2443 */ 2444 static int smack_socket_getpeersec_dgram(struct socket *sock, 2445 struct sk_buff *skb, u32 *secid) 2446 2447 { 2448 struct netlbl_lsm_secattr secattr; 2449 struct sock *sk; 2450 char smack[SMK_LABELLEN]; 2451 int family = PF_INET; 2452 u32 s; 2453 int rc; 2454 2455 /* 2456 * Only works for families with packets. 2457 */ 2458 if (sock != NULL) { 2459 sk = sock->sk; 2460 if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) 2461 return 0; 2462 family = sk->sk_family; 2463 } 2464 /* 2465 * Translate what netlabel gave us. 2466 */ 2467 netlbl_secattr_init(&secattr); 2468 rc = netlbl_skbuff_getattr(skb, family, &secattr); 2469 if (rc == 0) 2470 smack_from_secattr(&secattr, smack); 2471 netlbl_secattr_destroy(&secattr); 2472 2473 /* 2474 * Give up if we couldn't get anything 2475 */ 2476 if (rc != 0) 2477 return rc; 2478 2479 s = smack_to_secid(smack); 2480 if (s == 0) 2481 return -EINVAL; 2482 2483 *secid = s; 2484 return 0; 2485 } 2486 2487 /** 2488 * smack_sock_graft - Initialize a newly created socket with an existing sock 2489 * @sk: child sock 2490 * @parent: parent socket 2491 * 2492 * Set the smk_{in,out} state of an existing sock based on the process that 2493 * is creating the new socket. 2494 */ 2495 static void smack_sock_graft(struct sock *sk, struct socket *parent) 2496 { 2497 struct socket_smack *ssp; 2498 2499 if (sk == NULL || 2500 (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)) 2501 return; 2502 2503 ssp = sk->sk_security; 2504 ssp->smk_in = ssp->smk_out = current_security(); 2505 /* cssp->smk_packet is already set in smack_inet_csk_clone() */ 2506 } 2507 2508 /** 2509 * smack_inet_conn_request - Smack access check on connect 2510 * @sk: socket involved 2511 * @skb: packet 2512 * @req: unused 2513 * 2514 * Returns 0 if a task with the packet label could write to 2515 * the socket, otherwise an error code 2516 */ 2517 static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb, 2518 struct request_sock *req) 2519 { 2520 u16 family = sk->sk_family; 2521 struct socket_smack *ssp = sk->sk_security; 2522 struct netlbl_lsm_secattr secattr; 2523 struct sockaddr_in addr; 2524 struct iphdr *hdr; 2525 char smack[SMK_LABELLEN]; 2526 int rc; 2527 2528 /* handle mapped IPv4 packets arriving via IPv6 sockets */ 2529 if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP)) 2530 family = PF_INET; 2531 2532 netlbl_secattr_init(&secattr); 2533 rc = netlbl_skbuff_getattr(skb, family, &secattr); 2534 if (rc == 0) 2535 smack_from_secattr(&secattr, smack); 2536 else 2537 strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN); 2538 netlbl_secattr_destroy(&secattr); 2539 2540 /* 2541 * Receiving a packet requires that the other end be able to write 2542 * here. Read access is not required. 2543 */ 2544 rc = smk_access(smack, ssp->smk_in, MAY_WRITE); 2545 if (rc != 0) 2546 return rc; 2547 2548 /* 2549 * Save the peer's label in the request_sock so we can later setup 2550 * smk_packet in the child socket so that SO_PEERCRED can report it. 2551 */ 2552 req->peer_secid = smack_to_secid(smack); 2553 2554 /* 2555 * We need to decide if we want to label the incoming connection here 2556 * if we do we only need to label the request_sock and the stack will 2557 * propogate the wire-label to the sock when it is created. 2558 */ 2559 hdr = ip_hdr(skb); 2560 addr.sin_addr.s_addr = hdr->saddr; 2561 rcu_read_lock(); 2562 if (smack_host_label(&addr) == NULL) { 2563 rcu_read_unlock(); 2564 netlbl_secattr_init(&secattr); 2565 smack_to_secattr(smack, &secattr); 2566 rc = netlbl_req_setattr(req, &secattr); 2567 netlbl_secattr_destroy(&secattr); 2568 } else { 2569 rcu_read_unlock(); 2570 netlbl_req_delattr(req); 2571 } 2572 2573 return rc; 2574 } 2575 2576 /** 2577 * smack_inet_csk_clone - Copy the connection information to the new socket 2578 * @sk: the new socket 2579 * @req: the connection's request_sock 2580 * 2581 * Transfer the connection's peer label to the newly created socket. 2582 */ 2583 static void smack_inet_csk_clone(struct sock *sk, 2584 const struct request_sock *req) 2585 { 2586 struct socket_smack *ssp = sk->sk_security; 2587 char *smack; 2588 2589 if (req->peer_secid != 0) { 2590 smack = smack_from_secid(req->peer_secid); 2591 strncpy(ssp->smk_packet, smack, SMK_MAXLEN); 2592 } else 2593 ssp->smk_packet[0] = '\0'; 2594 } 2595 2596 /* 2597 * Key management security hooks 2598 * 2599 * Casey has not tested key support very heavily. 2600 * The permission check is most likely too restrictive. 2601 * If you care about keys please have a look. 2602 */ 2603 #ifdef CONFIG_KEYS 2604 2605 /** 2606 * smack_key_alloc - Set the key security blob 2607 * @key: object 2608 * @cred: the credentials to use 2609 * @flags: unused 2610 * 2611 * No allocation required 2612 * 2613 * Returns 0 2614 */ 2615 static int smack_key_alloc(struct key *key, const struct cred *cred, 2616 unsigned long flags) 2617 { 2618 key->security = cred->security; 2619 return 0; 2620 } 2621 2622 /** 2623 * smack_key_free - Clear the key security blob 2624 * @key: the object 2625 * 2626 * Clear the blob pointer 2627 */ 2628 static void smack_key_free(struct key *key) 2629 { 2630 key->security = NULL; 2631 } 2632 2633 /* 2634 * smack_key_permission - Smack access on a key 2635 * @key_ref: gets to the object 2636 * @cred: the credentials to use 2637 * @perm: unused 2638 * 2639 * Return 0 if the task has read and write to the object, 2640 * an error code otherwise 2641 */ 2642 static int smack_key_permission(key_ref_t key_ref, 2643 const struct cred *cred, key_perm_t perm) 2644 { 2645 struct key *keyp; 2646 2647 keyp = key_ref_to_ptr(key_ref); 2648 if (keyp == NULL) 2649 return -EINVAL; 2650 /* 2651 * If the key hasn't been initialized give it access so that 2652 * it may do so. 2653 */ 2654 if (keyp->security == NULL) 2655 return 0; 2656 /* 2657 * This should not occur 2658 */ 2659 if (cred->security == NULL) 2660 return -EACCES; 2661 2662 return smk_access(cred->security, keyp->security, MAY_READWRITE); 2663 } 2664 #endif /* CONFIG_KEYS */ 2665 2666 /* 2667 * Smack Audit hooks 2668 * 2669 * Audit requires a unique representation of each Smack specific 2670 * rule. This unique representation is used to distinguish the 2671 * object to be audited from remaining kernel objects and also 2672 * works as a glue between the audit hooks. 2673 * 2674 * Since repository entries are added but never deleted, we'll use 2675 * the smack_known label address related to the given audit rule as 2676 * the needed unique representation. This also better fits the smack 2677 * model where nearly everything is a label. 2678 */ 2679 #ifdef CONFIG_AUDIT 2680 2681 /** 2682 * smack_audit_rule_init - Initialize a smack audit rule 2683 * @field: audit rule fields given from user-space (audit.h) 2684 * @op: required testing operator (=, !=, >, <, ...) 2685 * @rulestr: smack label to be audited 2686 * @vrule: pointer to save our own audit rule representation 2687 * 2688 * Prepare to audit cases where (@field @op @rulestr) is true. 2689 * The label to be audited is created if necessay. 2690 */ 2691 static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule) 2692 { 2693 char **rule = (char **)vrule; 2694 *rule = NULL; 2695 2696 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 2697 return -EINVAL; 2698 2699 if (op != Audit_equal && op != Audit_not_equal) 2700 return -EINVAL; 2701 2702 *rule = smk_import(rulestr, 0); 2703 2704 return 0; 2705 } 2706 2707 /** 2708 * smack_audit_rule_known - Distinguish Smack audit rules 2709 * @krule: rule of interest, in Audit kernel representation format 2710 * 2711 * This is used to filter Smack rules from remaining Audit ones. 2712 * If it's proved that this rule belongs to us, the 2713 * audit_rule_match hook will be called to do the final judgement. 2714 */ 2715 static int smack_audit_rule_known(struct audit_krule *krule) 2716 { 2717 struct audit_field *f; 2718 int i; 2719 2720 for (i = 0; i < krule->field_count; i++) { 2721 f = &krule->fields[i]; 2722 2723 if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER) 2724 return 1; 2725 } 2726 2727 return 0; 2728 } 2729 2730 /** 2731 * smack_audit_rule_match - Audit given object ? 2732 * @secid: security id for identifying the object to test 2733 * @field: audit rule flags given from user-space 2734 * @op: required testing operator 2735 * @vrule: smack internal rule presentation 2736 * @actx: audit context associated with the check 2737 * 2738 * The core Audit hook. It's used to take the decision of 2739 * whether to audit or not to audit a given object. 2740 */ 2741 static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule, 2742 struct audit_context *actx) 2743 { 2744 char *smack; 2745 char *rule = vrule; 2746 2747 if (!rule) { 2748 audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR, 2749 "Smack: missing rule\n"); 2750 return -ENOENT; 2751 } 2752 2753 if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER) 2754 return 0; 2755 2756 smack = smack_from_secid(secid); 2757 2758 /* 2759 * No need to do string comparisons. If a match occurs, 2760 * both pointers will point to the same smack_known 2761 * label. 2762 */ 2763 if (op == Audit_equal) 2764 return (rule == smack); 2765 if (op == Audit_not_equal) 2766 return (rule != smack); 2767 2768 return 0; 2769 } 2770 2771 /** 2772 * smack_audit_rule_free - free smack rule representation 2773 * @vrule: rule to be freed. 2774 * 2775 * No memory was allocated. 2776 */ 2777 static void smack_audit_rule_free(void *vrule) 2778 { 2779 /* No-op */ 2780 } 2781 2782 #endif /* CONFIG_AUDIT */ 2783 2784 /** 2785 * smack_secid_to_secctx - return the smack label for a secid 2786 * @secid: incoming integer 2787 * @secdata: destination 2788 * @seclen: how long it is 2789 * 2790 * Exists for networking code. 2791 */ 2792 static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) 2793 { 2794 char *sp = smack_from_secid(secid); 2795 2796 *secdata = sp; 2797 *seclen = strlen(sp); 2798 return 0; 2799 } 2800 2801 /** 2802 * smack_secctx_to_secid - return the secid for a smack label 2803 * @secdata: smack label 2804 * @seclen: how long result is 2805 * @secid: outgoing integer 2806 * 2807 * Exists for audit and networking code. 2808 */ 2809 static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) 2810 { 2811 *secid = smack_to_secid(secdata); 2812 return 0; 2813 } 2814 2815 /** 2816 * smack_release_secctx - don't do anything. 2817 * @secdata: unused 2818 * @seclen: unused 2819 * 2820 * Exists to make sure nothing gets done, and properly 2821 */ 2822 static void smack_release_secctx(char *secdata, u32 seclen) 2823 { 2824 } 2825 2826 struct security_operations smack_ops = { 2827 .name = "smack", 2828 2829 .ptrace_may_access = smack_ptrace_may_access, 2830 .ptrace_traceme = smack_ptrace_traceme, 2831 .capget = cap_capget, 2832 .capset = cap_capset, 2833 .capable = cap_capable, 2834 .syslog = smack_syslog, 2835 .settime = cap_settime, 2836 .vm_enough_memory = cap_vm_enough_memory, 2837 2838 .bprm_set_creds = cap_bprm_set_creds, 2839 .bprm_secureexec = cap_bprm_secureexec, 2840 2841 .sb_alloc_security = smack_sb_alloc_security, 2842 .sb_free_security = smack_sb_free_security, 2843 .sb_copy_data = smack_sb_copy_data, 2844 .sb_kern_mount = smack_sb_kern_mount, 2845 .sb_statfs = smack_sb_statfs, 2846 .sb_mount = smack_sb_mount, 2847 .sb_umount = smack_sb_umount, 2848 2849 .inode_alloc_security = smack_inode_alloc_security, 2850 .inode_free_security = smack_inode_free_security, 2851 .inode_init_security = smack_inode_init_security, 2852 .inode_link = smack_inode_link, 2853 .inode_unlink = smack_inode_unlink, 2854 .inode_rmdir = smack_inode_rmdir, 2855 .inode_rename = smack_inode_rename, 2856 .inode_permission = smack_inode_permission, 2857 .inode_setattr = smack_inode_setattr, 2858 .inode_getattr = smack_inode_getattr, 2859 .inode_setxattr = smack_inode_setxattr, 2860 .inode_post_setxattr = smack_inode_post_setxattr, 2861 .inode_getxattr = smack_inode_getxattr, 2862 .inode_removexattr = smack_inode_removexattr, 2863 .inode_need_killpriv = cap_inode_need_killpriv, 2864 .inode_killpriv = cap_inode_killpriv, 2865 .inode_getsecurity = smack_inode_getsecurity, 2866 .inode_setsecurity = smack_inode_setsecurity, 2867 .inode_listsecurity = smack_inode_listsecurity, 2868 .inode_getsecid = smack_inode_getsecid, 2869 2870 .file_permission = smack_file_permission, 2871 .file_alloc_security = smack_file_alloc_security, 2872 .file_free_security = smack_file_free_security, 2873 .file_ioctl = smack_file_ioctl, 2874 .file_lock = smack_file_lock, 2875 .file_fcntl = smack_file_fcntl, 2876 .file_set_fowner = smack_file_set_fowner, 2877 .file_send_sigiotask = smack_file_send_sigiotask, 2878 .file_receive = smack_file_receive, 2879 2880 .cred_free = smack_cred_free, 2881 .cred_prepare = smack_cred_prepare, 2882 .cred_commit = smack_cred_commit, 2883 .kernel_act_as = smack_kernel_act_as, 2884 .kernel_create_files_as = smack_kernel_create_files_as, 2885 .task_fix_setuid = cap_task_fix_setuid, 2886 .task_setpgid = smack_task_setpgid, 2887 .task_getpgid = smack_task_getpgid, 2888 .task_getsid = smack_task_getsid, 2889 .task_getsecid = smack_task_getsecid, 2890 .task_setnice = smack_task_setnice, 2891 .task_setioprio = smack_task_setioprio, 2892 .task_getioprio = smack_task_getioprio, 2893 .task_setscheduler = smack_task_setscheduler, 2894 .task_getscheduler = smack_task_getscheduler, 2895 .task_movememory = smack_task_movememory, 2896 .task_kill = smack_task_kill, 2897 .task_wait = smack_task_wait, 2898 .task_to_inode = smack_task_to_inode, 2899 .task_prctl = cap_task_prctl, 2900 2901 .ipc_permission = smack_ipc_permission, 2902 .ipc_getsecid = smack_ipc_getsecid, 2903 2904 .msg_msg_alloc_security = smack_msg_msg_alloc_security, 2905 .msg_msg_free_security = smack_msg_msg_free_security, 2906 2907 .msg_queue_alloc_security = smack_msg_queue_alloc_security, 2908 .msg_queue_free_security = smack_msg_queue_free_security, 2909 .msg_queue_associate = smack_msg_queue_associate, 2910 .msg_queue_msgctl = smack_msg_queue_msgctl, 2911 .msg_queue_msgsnd = smack_msg_queue_msgsnd, 2912 .msg_queue_msgrcv = smack_msg_queue_msgrcv, 2913 2914 .shm_alloc_security = smack_shm_alloc_security, 2915 .shm_free_security = smack_shm_free_security, 2916 .shm_associate = smack_shm_associate, 2917 .shm_shmctl = smack_shm_shmctl, 2918 .shm_shmat = smack_shm_shmat, 2919 2920 .sem_alloc_security = smack_sem_alloc_security, 2921 .sem_free_security = smack_sem_free_security, 2922 .sem_associate = smack_sem_associate, 2923 .sem_semctl = smack_sem_semctl, 2924 .sem_semop = smack_sem_semop, 2925 2926 .netlink_send = cap_netlink_send, 2927 .netlink_recv = cap_netlink_recv, 2928 2929 .d_instantiate = smack_d_instantiate, 2930 2931 .getprocattr = smack_getprocattr, 2932 .setprocattr = smack_setprocattr, 2933 2934 .unix_stream_connect = smack_unix_stream_connect, 2935 .unix_may_send = smack_unix_may_send, 2936 2937 .socket_post_create = smack_socket_post_create, 2938 .socket_connect = smack_socket_connect, 2939 .socket_sendmsg = smack_socket_sendmsg, 2940 .socket_sock_rcv_skb = smack_socket_sock_rcv_skb, 2941 .socket_getpeersec_stream = smack_socket_getpeersec_stream, 2942 .socket_getpeersec_dgram = smack_socket_getpeersec_dgram, 2943 .sk_alloc_security = smack_sk_alloc_security, 2944 .sk_free_security = smack_sk_free_security, 2945 .sock_graft = smack_sock_graft, 2946 .inet_conn_request = smack_inet_conn_request, 2947 .inet_csk_clone = smack_inet_csk_clone, 2948 2949 /* key management security hooks */ 2950 #ifdef CONFIG_KEYS 2951 .key_alloc = smack_key_alloc, 2952 .key_free = smack_key_free, 2953 .key_permission = smack_key_permission, 2954 #endif /* CONFIG_KEYS */ 2955 2956 /* Audit hooks */ 2957 #ifdef CONFIG_AUDIT 2958 .audit_rule_init = smack_audit_rule_init, 2959 .audit_rule_known = smack_audit_rule_known, 2960 .audit_rule_match = smack_audit_rule_match, 2961 .audit_rule_free = smack_audit_rule_free, 2962 #endif /* CONFIG_AUDIT */ 2963 2964 .secid_to_secctx = smack_secid_to_secctx, 2965 .secctx_to_secid = smack_secctx_to_secid, 2966 .release_secctx = smack_release_secctx, 2967 }; 2968 2969 2970 static __init void init_smack_know_list(void) 2971 { 2972 list_add(&smack_known_huh.list, &smack_known_list); 2973 list_add(&smack_known_hat.list, &smack_known_list); 2974 list_add(&smack_known_star.list, &smack_known_list); 2975 list_add(&smack_known_floor.list, &smack_known_list); 2976 list_add(&smack_known_invalid.list, &smack_known_list); 2977 list_add(&smack_known_web.list, &smack_known_list); 2978 } 2979 2980 /** 2981 * smack_init - initialize the smack system 2982 * 2983 * Returns 0 2984 */ 2985 static __init int smack_init(void) 2986 { 2987 struct cred *cred; 2988 2989 if (!security_module_enable(&smack_ops)) 2990 return 0; 2991 2992 printk(KERN_INFO "Smack: Initializing.\n"); 2993 2994 /* 2995 * Set the security state for the initial task. 2996 */ 2997 cred = (struct cred *) current->cred; 2998 cred->security = &smack_known_floor.smk_known; 2999 3000 /* initilize the smack_know_list */ 3001 init_smack_know_list(); 3002 /* 3003 * Initialize locks 3004 */ 3005 spin_lock_init(&smack_known_huh.smk_cipsolock); 3006 spin_lock_init(&smack_known_hat.smk_cipsolock); 3007 spin_lock_init(&smack_known_star.smk_cipsolock); 3008 spin_lock_init(&smack_known_floor.smk_cipsolock); 3009 spin_lock_init(&smack_known_invalid.smk_cipsolock); 3010 3011 /* 3012 * Register with LSM 3013 */ 3014 if (register_security(&smack_ops)) 3015 panic("smack: Unable to register with kernel.\n"); 3016 3017 return 0; 3018 } 3019 3020 /* 3021 * Smack requires early initialization in order to label 3022 * all processes and objects when they are created. 3023 */ 3024 security_initcall(smack_init); 3025