security/mac_process.c

   1 /*
   2  * Copyright (c) 2007-2010 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 /*-
  30  * Copyright (c) 1999, 2000, 2001, 2002 Robert N. M. Watson
  31  * Copyright (c) 2001 Ilmar S. Habibulin
  32  * Copyright (c) 2001, 2002, 2003, 2004 Networks Associates Technology, Inc.
  33  *
  34  * This software was developed by Robert Watson and Ilmar Habibulin for the
  35  * TrustedBSD Project.
  36  *
  37  * This software was developed for the FreeBSD Project in part by Network
  38  * Associates Laboratories, the Security Research Division of Network
  39  * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
  40  * as part of the DARPA CHATS research program.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions
  44  * are met:
  45  * 1. Redistributions of source code must retain the above copyright
  46  *    notice, this list of conditions and the following disclaimer.
  47  * 2. Redistributions in binary form must reproduce the above copyright
  48  *    notice, this list of conditions and the following disclaimer in the
  49  *    documentation and/or other materials provided with the distribution.
  50  *
  51  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  61  * SUCH DAMAGE.
  62  *
  63  */
  64
  65 #include <string.h>
  66 #include <sys/param.h>
  67 #include <sys/ucred.h>
  68 #include <sys/malloc.h>
  69 #include <sys/sbuf.h>
  70 #include <sys/vnode.h>
  71 #include <sys/proc.h>
  72 #include <sys/proc_internal.h>
  73 #include <sys/kauth.h>
  74 #include <sys/imgact.h>
  75 #include <mach/mach_types.h>
  76 #include <kern/task.h>
  77
  78 #include <security/mac_internal.h>
  79 #include <security/mac_mach_internal.h>
  80
  81 #include <bsd/security/audit/audit.h>
  82
  83 struct label *
  84 mac_cred_label_alloc(void)
  85 {
  86         struct label *label;
  87
  88         label = mac_labelzone_alloc(MAC_WAITOK);
  89         if (label == NULL) {
  90                 return NULL;
  91         }
  92         MAC_PERFORM(cred_label_init, label);
  93         return label;
  94 }
  95
  96 void
  97 mac_cred_label_init(struct ucred *cred)
  98 {
  99         cred->cr_label = mac_cred_label_alloc();
 100 }
 101
 102 void
 103 mac_cred_label_free(struct label *label)
 104 {
 105         MAC_PERFORM(cred_label_destroy, label);
 106         mac_labelzone_free(label);
 107 }
 108
 109 int
 110 mac_cred_label_compare(struct label *a, struct label *b)
 111 {
 112         return bcmp(a, b, sizeof(*a)) == 0;
 113 }
 114
 115 int
 116 mac_cred_label_externalize_audit(struct proc *p, struct mac *mac)
 117 {
 118         kauth_cred_t cr;
 119         int error;
 120
 121         cr = kauth_cred_proc_ref(p);
 122
 123         error = MAC_EXTERNALIZE_AUDIT(cred, cr->cr_label,
 124             mac->m_string, mac->m_buflen);
 125
 126         kauth_cred_unref(&cr);
 127         return error;
 128 }
 129
 130 void
 131 mac_cred_label_destroy(kauth_cred_t cred)
 132 {
 133         mac_cred_label_free(cred->cr_label);
 134         cred->cr_label = NULL;
 135 }
 136
 137 int
 138 mac_cred_label_externalize(struct label *label, char *elements,
 139     char *outbuf, size_t outbuflen, int flags __unused)
 140 {
 141         int error = 0;
 142
 143         error = MAC_EXTERNALIZE(cred, label, elements, outbuf, outbuflen);
 144
 145         return error;
 146 }
 147
 148 int
 149 mac_cred_label_internalize(struct label *label, char *string)
 150 {
 151         int error;
 152
 153         error = MAC_INTERNALIZE(cred, label, string);
 154
 155         return error;
 156 }
 157
 158 /*
 159  * By default, fork just adds a reference to the parent
 160  * credential.  Policies may need to know about this reference
 161  * if they are tracking exit calls to know when to free the
 162  * label.
 163  */
 164 void
 165 mac_cred_label_associate_fork(kauth_cred_t cred, proc_t proc)
 166 {
 167         MAC_PERFORM(cred_label_associate_fork, cred, proc);
 168 }
 169
 170 /*
 171  * Initialize MAC label for the first kernel process, from which other
 172  * kernel processes and threads are spawned.
 173  */
 174 void
 175 mac_cred_label_associate_kernel(kauth_cred_t cred)
 176 {
 177         MAC_PERFORM(cred_label_associate_kernel, cred);
 178 }
 179
 180 /*
 181  * Initialize MAC label for the first userland process, from which other
 182  * userland processes and threads are spawned.
 183  */
 184 void
 185 mac_cred_label_associate_user(kauth_cred_t cred)
 186 {
 187         MAC_PERFORM(cred_label_associate_user, cred);
 188 }
 189
 190 /*
 191  * When a new process is created, its label must be initialized.  Generally,
 192  * this involves inheritence from the parent process, modulo possible
 193  * deltas.  This function allows that processing to take place.
 194  */
 195 void
 196 mac_cred_label_associate(struct ucred *parent_cred, struct ucred *child_cred)
 197 {
 198         MAC_PERFORM(cred_label_associate, parent_cred, child_cred);
 199 }
 200
 201 int
 202 mac_execve_enter(user_addr_t mac_p, struct image_params *imgp)
 203 {
 204         struct user_mac mac;
 205         struct label *execlabel;
 206         char *buffer;
 207         int error;
 208         size_t ulen;
 209
 210         if (mac_p == USER_ADDR_NULL) {
 211                 return 0;
 212         }
 213
 214         if (IS_64BIT_PROCESS(current_proc())) {
 215                 struct user64_mac mac64;
 216                 error = copyin(mac_p, &mac64, sizeof(mac64));
 217                 mac.m_buflen = mac64.m_buflen;
 218                 mac.m_string = mac64.m_string;
 219         } else {
 220                 struct user32_mac mac32;
 221                 error = copyin(mac_p, &mac32, sizeof(mac32));
 222                 mac.m_buflen = mac32.m_buflen;
 223                 mac.m_string = mac32.m_string;
 224         }
 225         if (error) {
 226                 return error;
 227         }
 228
 229         error = mac_check_structmac_consistent(&mac);
 230         if (error) {
 231                 return error;
 232         }
 233
 234         execlabel = mac_cred_label_alloc();
 235         MALLOC(buffer, char *, mac.m_buflen, M_MACTEMP, M_WAITOK);
 236         error = copyinstr(CAST_USER_ADDR_T(mac.m_string), buffer, mac.m_buflen, &ulen);
 237         if (error) {
 238                 goto out;
 239         }
 240         AUDIT_ARG(mac_string, buffer);
 241
 242         error = mac_cred_label_internalize(execlabel, buffer);
 243 out:
 244         if (error) {
 245                 mac_cred_label_free(execlabel);
 246                 execlabel = NULL;
 247         }
 248         imgp->ip_execlabelp = execlabel;
 249         FREE(buffer, M_MACTEMP);
 250         return error;
 251 }
 252
 253 /*
 254  * When the subject's label changes, it may require revocation of privilege
 255  * to mapped objects.  This can't be done on-the-fly later with a unified
 256  * buffer cache.
 257  *
 258  * XXX:         CRF_MAC_ENFORCE should be in a kauth_cred_t field, rather
 259  * XXX:         than a posix_cred_t field.
 260  */
 261 void
 262 mac_cred_label_update(kauth_cred_t cred, struct label *newlabel)
 263 {
 264         posix_cred_t pcred = posix_cred_get(cred);
 265
 266         /* force label to be part of "matching" for credential */
 267         pcred->cr_flags |= CRF_MAC_ENFORCE;
 268
 269         /* inform the policies of the update */
 270         MAC_PERFORM(cred_label_update, cred, newlabel);
 271 }
 272
 273 int
 274 mac_cred_check_label_update(kauth_cred_t cred, struct label *newlabel)
 275 {
 276         int error;
 277
 278 #if SECURITY_MAC_CHECK_ENFORCE
 279         /* 21167099 - only check if we allow write */
 280         if (!mac_proc_enforce) {
 281                 return 0;
 282         }
 283 #endif
 284
 285         MAC_CHECK(cred_check_label_update, cred, newlabel);
 286
 287         return error;
 288 }
 289
 290 int
 291 mac_cred_check_visible(kauth_cred_t u1, kauth_cred_t u2)
 292 {
 293         int error;
 294
 295 #if SECURITY_MAC_CHECK_ENFORCE
 296         /* 21167099 - only check if we allow write */
 297         if (!mac_proc_enforce) {
 298                 return 0;
 299         }
 300 #endif
 301
 302         MAC_CHECK(cred_check_visible, u1, u2);
 303
 304         return error;
 305 }
 306
 307 int
 308 mac_proc_check_debug(proc_t curp, struct proc *proc)
 309 {
 310         kauth_cred_t cred;
 311         int error;
 312
 313 #if SECURITY_MAC_CHECK_ENFORCE
 314         /* 21167099 - only check if we allow write */
 315         if (!mac_proc_enforce) {
 316                 return 0;
 317         }
 318 #endif
 319         if (!mac_proc_check_enforce(curp)) {
 320                 return 0;
 321         }
 322
 323         cred = kauth_cred_proc_ref(curp);
 324         MAC_CHECK(proc_check_debug, cred, proc);
 325         kauth_cred_unref(&cred);
 326
 327         return error;
 328 }
 329
 330 int
 331 mac_proc_check_fork(proc_t curp)
 332 {
 333         kauth_cred_t cred;
 334         int error;
 335
 336 #if SECURITY_MAC_CHECK_ENFORCE
 337         /* 21167099 - only check if we allow write */
 338         if (!mac_proc_enforce) {
 339                 return 0;
 340         }
 341 #endif
 342         if (!mac_proc_check_enforce(curp)) {
 343                 return 0;
 344         }
 345
 346         cred = kauth_cred_proc_ref(curp);
 347         MAC_CHECK(proc_check_fork, cred, curp);
 348         kauth_cred_unref(&cred);
 349
 350         return error;
 351 }
 352
 353 int
 354 mac_proc_check_get_task_name(struct ucred *cred, struct proc *p)
 355 {
 356         int error;
 357
 358         MAC_CHECK(proc_check_get_task_name, cred, p);
 359
 360         return error;
 361 }
 362
 363 int
 364 mac_proc_check_get_task(struct ucred *cred, struct proc *p)
 365 {
 366         int error;
 367
 368         MAC_CHECK(proc_check_get_task, cred, p);
 369
 370         return error;
 371 }
 372
 373 int
 374 mac_proc_check_expose_task(struct ucred *cred, struct proc *p)
 375 {
 376         int error;
 377
 378         MAC_CHECK(proc_check_expose_task, cred, p);
 379
 380         return error;
 381 }
 382
 383 int
 384 mac_proc_check_inherit_ipc_ports(struct proc *p, struct vnode *cur_vp, off_t cur_offset, struct vnode *img_vp, off_t img_offset, struct vnode *scriptvp)
 385 {
 386         int error;
 387
 388         MAC_CHECK(proc_check_inherit_ipc_ports, p, cur_vp, cur_offset, img_vp, img_offset, scriptvp);
 389
 390         return error;
 391 }
 392
 393 /*
 394  * The type of maxprot in proc_check_map_anon must be equivalent to vm_prot_t
 395  * (defined in <mach/vm_prot.h>). mac_policy.h does not include any header
 396  * files, so cannot use the typedef itself.
 397  */
 398 int
 399 mac_proc_check_map_anon(proc_t proc, user_addr_t u_addr,
 400     user_size_t u_size, int prot, int flags, int *maxprot)
 401 {
 402         kauth_cred_t cred;
 403         int error;
 404
 405 #if SECURITY_MAC_CHECK_ENFORCE
 406         /* 21167099 - only check if we allow write */
 407         if (!mac_vm_enforce) {
 408                 return 0;
 409         }
 410 #endif
 411         if (!mac_proc_check_enforce(proc)) {
 412                 return 0;
 413         }
 414
 415         cred = kauth_cred_proc_ref(proc);
 416         MAC_CHECK(proc_check_map_anon, proc, cred, u_addr, u_size, prot, flags, maxprot);
 417         kauth_cred_unref(&cred);
 418
 419         return error;
 420 }
 421
 422 int
 423 mac_proc_check_mprotect(proc_t proc,
 424     user_addr_t addr, user_size_t size, int prot)
 425 {
 426         kauth_cred_t cred;
 427         int error;
 428
 429 #if SECURITY_MAC_CHECK_ENFORCE
 430         /* 21167099 - only check if we allow write */
 431         if (!mac_vm_enforce) {
 432                 return 0;
 433         }
 434 #endif
 435         if (!mac_proc_check_enforce(proc)) {
 436                 return 0;
 437         }
 438
 439         cred = kauth_cred_proc_ref(proc);
 440         MAC_CHECK(proc_check_mprotect, cred, proc, addr, size, prot);
 441         kauth_cred_unref(&cred);
 442
 443         return error;
 444 }
 445
 446 int
 447 mac_proc_check_run_cs_invalid(proc_t proc)
 448 {
 449         int error;
 450
 451 #if SECURITY_MAC_CHECK_ENFORCE
 452         /* 21167099 - only check if we allow write */
 453         if (!mac_vm_enforce) {
 454                 return 0;
 455         }
 456 #endif
 457
 458         MAC_CHECK(proc_check_run_cs_invalid, proc);
 459
 460         return error;
 461 }
 462
 463 int
 464 mac_proc_check_sched(proc_t curp, struct proc *proc)
 465 {
 466         kauth_cred_t cred;
 467         int error;
 468
 469 #if SECURITY_MAC_CHECK_ENFORCE
 470         /* 21167099 - only check if we allow write */
 471         if (!mac_proc_enforce) {
 472                 return 0;
 473         }
 474 #endif
 475         if (!mac_proc_check_enforce(curp)) {
 476                 return 0;
 477         }
 478
 479         cred = kauth_cred_proc_ref(curp);
 480         MAC_CHECK(proc_check_sched, cred, proc);
 481         kauth_cred_unref(&cred);
 482
 483         return error;
 484 }
 485
 486 int
 487 mac_proc_check_signal(proc_t curp, struct proc *proc, int signum)
 488 {
 489         kauth_cred_t cred;
 490         int error;
 491
 492 #if SECURITY_MAC_CHECK_ENFORCE
 493         /* 21167099 - only check if we allow write */
 494         if (!mac_proc_enforce) {
 495                 return 0;
 496         }
 497 #endif
 498         if (!mac_proc_check_enforce(curp)) {
 499                 return 0;
 500         }
 501
 502         cred = kauth_cred_proc_ref(curp);
 503         MAC_CHECK(proc_check_signal, cred, proc, signum);
 504         kauth_cred_unref(&cred);
 505
 506         return error;
 507 }
 508
 509 int
 510 mac_proc_check_syscall_unix(proc_t curp, int scnum)
 511 {
 512         int error;
 513
 514 #if SECURITY_MAC_CHECK_ENFORCE
 515         /* 21167099 - only check if we allow write */
 516         if (!mac_proc_enforce) {
 517                 return 0;
 518         }
 519 #endif
 520         if (!mac_proc_check_enforce(curp)) {
 521                 return 0;
 522         }
 523
 524         MAC_CHECK(proc_check_syscall_unix, curp, scnum);
 525
 526         return error;
 527 }
 528
 529 int
 530 mac_proc_check_wait(proc_t curp, struct proc *proc)
 531 {
 532         kauth_cred_t cred;
 533         int error;
 534
 535 #if SECURITY_MAC_CHECK_ENFORCE
 536         /* 21167099 - only check if we allow write */
 537         if (!mac_proc_enforce) {
 538                 return 0;
 539         }
 540 #endif
 541         if (!mac_proc_check_enforce(curp)) {
 542                 return 0;
 543         }
 544
 545         cred = kauth_cred_proc_ref(curp);
 546         MAC_CHECK(proc_check_wait, cred, proc);
 547         kauth_cred_unref(&cred);
 548
 549         return error;
 550 }
 551
 552 void
 553 mac_proc_notify_exit(struct proc *proc)
 554 {
 555         MAC_PERFORM(proc_notify_exit, proc);
 556 }
 557
 558 int
 559 mac_proc_check_suspend_resume(proc_t curp, int sr)
 560 {
 561         kauth_cred_t cred;
 562         int error;
 563
 564 #if SECURITY_MAC_CHECK_ENFORCE
 565         /* 21167099 - only check if we allow write */
 566         if (!mac_proc_enforce) {
 567                 return 0;
 568         }
 569 #endif
 570         if (!mac_proc_check_enforce(curp)) {
 571                 return 0;
 572         }
 573
 574         cred = kauth_cred_proc_ref(curp);
 575         MAC_CHECK(proc_check_suspend_resume, cred, curp, sr);
 576         kauth_cred_unref(&cred);
 577
 578         return error;
 579 }
 580
 581 int
 582 mac_proc_check_ledger(proc_t curp, proc_t proc, int ledger_op)
 583 {
 584         kauth_cred_t cred;
 585         int error = 0;
 586
 587 #if SECURITY_MAC_CHECK_ENFORCE
 588         /* 21167099 - only check if we allow write */
 589         if (!mac_proc_enforce) {
 590                 return 0;
 591         }
 592 #endif
 593         if (!mac_proc_check_enforce(curp)) {
 594                 return 0;
 595         }
 596
 597         cred = kauth_cred_proc_ref(curp);
 598         MAC_CHECK(proc_check_ledger, cred, proc, ledger_op);
 599         kauth_cred_unref(&cred);
 600
 601         return error;
 602 }
 603
 604 int
 605 mac_proc_check_proc_info(proc_t curp, proc_t target, int callnum, int flavor)
 606 {
 607         kauth_cred_t cred;
 608         int error = 0;
 609
 610 #if SECURITY_MAC_CHECK_ENFORCE
 611         /* 21167099 - only check if we allow write */
 612         if (!mac_proc_enforce) {
 613                 return 0;
 614         }
 615 #endif
 616         if (!mac_proc_check_enforce(curp)) {
 617                 return 0;
 618         }
 619
 620         cred = kauth_cred_proc_ref(curp);
 621         MAC_CHECK(proc_check_proc_info, cred, target, callnum, flavor);
 622         kauth_cred_unref(&cred);
 623
 624         return error;
 625 }
 626
 627 int
 628 mac_proc_check_get_cs_info(proc_t curp, proc_t target, unsigned int op)
 629 {
 630         kauth_cred_t cred;
 631         int error = 0;
 632
 633 #if SECURITY_MAC_CHECK_ENFORCE
 634         /* 21167099 - only check if we allow write */
 635         if (!mac_proc_enforce) {
 636                 return 0;
 637         }
 638 #endif
 639         if (!mac_proc_check_enforce(curp)) {
 640                 return 0;
 641         }
 642
 643         cred = kauth_cred_proc_ref(curp);
 644         MAC_CHECK(proc_check_get_cs_info, cred, target, op);
 645         kauth_cred_unref(&cred);
 646
 647         return error;
 648 }
 649
 650 int
 651 mac_proc_check_set_cs_info(proc_t curp, proc_t target, unsigned int op)
 652 {
 653         kauth_cred_t cred;
 654         int error = 0;
 655
 656 #if SECURITY_MAC_CHECK_ENFORCE
 657         /* 21167099 - only check if we allow write */
 658         if (!mac_proc_enforce) {
 659                 return 0;
 660         }
 661 #endif
 662         if (!mac_proc_check_enforce(curp)) {
 663                 return 0;
 664         }
 665
 666         cred = kauth_cred_proc_ref(curp);
 667         MAC_CHECK(proc_check_set_cs_info, cred, target, op);
 668         kauth_cred_unref(&cred);
 669
 670         return error;
 671 }