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
  77 #include <security/mac_internal.h>
  78 #include <security/mac_mach_internal.h>
  79
  80 #include <bsd/security/audit/audit.h>
  81
  82 struct label *
  83 mac_cred_label_alloc(void)
  84 {
  85         struct label *label;
  86
  87         label = mac_labelzone_alloc(MAC_WAITOK);
  88         if (label == NULL)
  89                 return (NULL);
  90         MAC_PERFORM(cred_label_init, label);
  91         return (label);
  92 }
  93
  94 void
  95 mac_cred_label_init(struct ucred *cred)
  96 {
  97         cred->cr_label = mac_cred_label_alloc();
  98 }
  99
 100 void
 101 mac_cred_label_free(struct label *label)
 102 {
 103         MAC_PERFORM(cred_label_destroy, label);
 104         mac_labelzone_free(label);
 105 }
 106
 107 int
 108 mac_cred_label_compare(struct label *a, struct label *b)
 109 {
 110         return (bcmp(a, b, sizeof (*a)) == 0);
 111 }
 112
 113 int
 114 mac_cred_label_externalize_audit(struct proc *p, struct mac *mac)
 115 {
 116         kauth_cred_t cr;
 117         int error;
 118
 119         cr = kauth_cred_proc_ref(p);
 120
 121         error = MAC_EXTERNALIZE_AUDIT(cred, cr->cr_label,
 122             mac->m_string, mac->m_buflen);
 123
 124         kauth_cred_unref(&cr);
 125         return (error);
 126 }
 127
 128 void
 129 mac_cred_label_destroy(kauth_cred_t cred)
 130 {
 131
 132         mac_cred_label_free(cred->cr_label);
 133         cred->cr_label = NULL;
 134 }
 135
 136 int
 137 mac_cred_label_externalize(struct label *label, char *elements,
 138     char *outbuf, size_t outbuflen, int flags __unused)
 139 {
 140         int error = 0;
 141
 142         error = MAC_EXTERNALIZE(cred, label, elements, outbuf, outbuflen);
 143
 144         return (error);
 145 }
 146
 147 int
 148 mac_cred_label_internalize(struct label *label, char *string)
 149 {
 150         int error;
 151
 152         error = MAC_INTERNALIZE(cred, label, string);
 153
 154         return (error);
 155 }
 156
 157 /*
 158  * By default, fork just adds a reference to the parent
 159  * credential.  Policies may need to know about this reference
 160  * if they are tracking exit calls to know when to free the
 161  * label.
 162  */
 163 void
 164 mac_cred_label_associate_fork(kauth_cred_t cred, proc_t proc)
 165 {
 166         MAC_PERFORM(cred_label_associate_fork, cred, proc);
 167 }
 168
 169 /*
 170  * Initialize MAC label for the first kernel process, from which other
 171  * kernel processes and threads are spawned.
 172  */
 173 void
 174 mac_cred_label_associate_kernel(kauth_cred_t cred)
 175 {
 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
 188         MAC_PERFORM(cred_label_associate_user, cred);
 189 }
 190
 191 /*
 192  * When a new process is created, its label must be initialized.  Generally,
 193  * this involves inheritence from the parent process, modulo possible
 194  * deltas.  This function allows that processing to take place.
 195  */
 196 void
 197 mac_cred_label_associate(struct ucred *parent_cred, struct ucred *child_cred)
 198 {
 199
 200         MAC_PERFORM(cred_label_associate, parent_cred, child_cred);
 201 }
 202
 203 int
 204 mac_execve_enter(user_addr_t mac_p, struct image_params *imgp)
 205 {
 206         struct user_mac mac;
 207         struct label *execlabel;
 208         char *buffer;
 209         int error;
 210         size_t ulen;
 211
 212         if (mac_p == USER_ADDR_NULL)
 213                 return (0);
 214
 215         if (IS_64BIT_PROCESS(current_proc())) {
 216                 struct user64_mac mac64;
 217                 error = copyin(mac_p, &mac64, sizeof(mac64));
 218                 mac.m_buflen = mac64.m_buflen;
 219                 mac.m_string = mac64.m_string;
 220         } else {
 221                 struct user32_mac mac32;
 222                 error = copyin(mac_p, &mac32, sizeof(mac32));
 223                 mac.m_buflen = mac32.m_buflen;
 224                 mac.m_string = mac32.m_string;
 225         }
 226         if (error)
 227                 return (error);
 228
 229         error = mac_check_structmac_consistent(&mac);
 230         if (error)
 231                 return (error);
 232
 233         execlabel = mac_cred_label_alloc();
 234         MALLOC(buffer, char *, mac.m_buflen, M_MACTEMP, M_WAITOK);
 235         error = copyinstr(CAST_USER_ADDR_T(mac.m_string), buffer, mac.m_buflen, &ulen);
 236         if (error)
 237                 goto out;
 238         AUDIT_ARG(mac_string, buffer);
 239
 240         error = mac_cred_label_internalize(execlabel, buffer);
 241 out:
 242         if (error) {
 243                 mac_cred_label_free(execlabel);
 244                 execlabel = NULL;
 245         }
 246         imgp->ip_execlabelp = execlabel;
 247         FREE(buffer, M_MACTEMP);
 248         return (error);
 249 }
 250
 251 /*
 252  * When the subject's label changes, it may require revocation of privilege
 253  * to mapped objects.  This can't be done on-the-fly later with a unified
 254  * buffer cache.
 255  *
 256  * XXX:         CRF_MAC_ENFORCE should be in a kauth_cred_t field, rather
 257  * XXX:         than a posix_cred_t field.
 258  */
 259 void
 260 mac_cred_label_update(kauth_cred_t cred, struct label *newlabel)
 261 {
 262         posix_cred_t pcred = posix_cred_get(cred);
 263
 264         /* force label to be part of "matching" for credential */
 265         pcred->cr_flags |= CRF_MAC_ENFORCE;
 266
 267         /* inform the policies of the update */
 268         MAC_PERFORM(cred_label_update, cred, newlabel);
 269 }
 270
 271 int
 272 mac_cred_check_label_update(kauth_cred_t cred, struct label *newlabel)
 273 {
 274         int error;
 275
 276         if (!mac_proc_enforce)
 277                 return (0);
 278
 279         MAC_CHECK(cred_check_label_update, cred, newlabel);
 280
 281         return (error);
 282 }
 283
 284 int
 285 mac_cred_check_visible(kauth_cred_t u1, kauth_cred_t u2)
 286 {
 287         int error;
 288
 289
 290
 291         if (!mac_proc_enforce)
 292                 return (0);
 293
 294
 295
 296         MAC_CHECK(cred_check_visible, u1, u2);
 297
 298
 299         return (error);
 300 }
 301
 302 /*
 303  * called with process locked.
 304  */
 305 void mac_proc_set_enforce(proc_t p, int enforce_flags)
 306 {
 307         p->p_mac_enforce |= enforce_flags;
 308 }
 309
 310 int
 311 mac_proc_check_debug(proc_t curp, struct proc *proc)
 312 {
 313         kauth_cred_t cred;
 314         int error;
 315
 316
 317
 318         if (!mac_proc_enforce ||
 319             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 320                 return (0);
 321
 322         cred = kauth_cred_proc_ref(curp);
 323         MAC_CHECK(proc_check_debug, cred, proc);
 324         kauth_cred_unref(&cred);
 325
 326         return (error);
 327 }
 328
 329 int
 330 mac_proc_check_fork(proc_t curp)
 331 {
 332         kauth_cred_t cred;
 333         int error;
 334
 335         if (!mac_proc_enforce ||
 336             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 337                 return (0);
 338
 339         cred = kauth_cred_proc_ref(curp);
 340         MAC_CHECK(proc_check_fork, cred, curp);
 341         kauth_cred_unref(&cred);
 342
 343         return (error);
 344 }
 345
 346 int
 347 mac_proc_check_get_task_name(struct ucred *cred, struct proc *p)
 348 {
 349         int error;
 350
 351         MAC_CHECK(proc_check_get_task_name, cred, p);
 352
 353         return (error);
 354 }
 355
 356 int
 357 mac_proc_check_get_task(struct ucred *cred, struct proc *p)
 358 {
 359         int error;
 360
 361         MAC_CHECK(proc_check_get_task, cred, p);
 362
 363         return (error);
 364 }
 365
 366 /*
 367  * The type of maxprot in proc_check_map_anon must be equivalent to vm_prot_t
 368  * (defined in <mach/vm_prot.h>). mac_policy.h does not include any header
 369  * files, so cannot use the typedef itself.
 370  */
 371 int
 372 mac_proc_check_map_anon(proc_t proc, user_addr_t u_addr,
 373     user_size_t u_size, int prot, int flags, int *maxprot)
 374 {
 375         kauth_cred_t cred;
 376         int error;
 377
 378         if (!mac_vm_enforce ||
 379             !mac_proc_check_enforce(proc, MAC_VM_ENFORCE))
 380                 return (0);
 381
 382         cred = kauth_cred_proc_ref(proc);
 383         MAC_CHECK(proc_check_map_anon, proc, cred, u_addr, u_size, prot, flags, maxprot);
 384         kauth_cred_unref(&cred);
 385
 386         return (error);
 387 }
 388
 389 int
 390 mac_proc_check_mprotect(proc_t proc,
 391     user_addr_t addr, user_size_t size, int prot)
 392 {
 393         kauth_cred_t cred;
 394         int error;
 395
 396         if (!mac_vm_enforce ||
 397             !mac_proc_check_enforce(proc, MAC_VM_ENFORCE))
 398                 return (0);
 399
 400         cred = kauth_cred_proc_ref(proc);
 401         MAC_CHECK(proc_check_mprotect, cred, proc, addr, size, prot);
 402         kauth_cred_unref(&cred);
 403
 404         return (error);
 405 }
 406
 407 int
 408 mac_proc_check_run_cs_invalid(proc_t proc)
 409 {
 410         int error;
 411
 412         if (!mac_vm_enforce) return (0);
 413
 414         MAC_CHECK(proc_check_run_cs_invalid, proc);
 415
 416         return (error);
 417 }
 418
 419 int
 420 mac_proc_check_sched(proc_t curp, struct proc *proc)
 421 {
 422         kauth_cred_t cred;
 423         int error;
 424
 425
 426
 427         if (!mac_proc_enforce ||
 428             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 429                 return (0);
 430
 431         cred = kauth_cred_proc_ref(curp);
 432         MAC_CHECK(proc_check_sched, cred, proc);
 433         kauth_cred_unref(&cred);
 434
 435         return (error);
 436 }
 437
 438 int
 439 mac_proc_check_signal(proc_t curp, struct proc *proc, int signum)
 440 {
 441         kauth_cred_t cred;
 442         int error;
 443
 444
 445
 446         if (!mac_proc_enforce ||
 447             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 448                 return (0);
 449
 450         cred = kauth_cred_proc_ref(curp);
 451         MAC_CHECK(proc_check_signal, cred, proc, signum);
 452         kauth_cred_unref(&cred);
 453
 454         return (error);
 455 }
 456
 457 int
 458 mac_proc_check_wait(proc_t curp, struct proc *proc)
 459 {
 460         kauth_cred_t cred;
 461         int error;
 462
 463
 464
 465         if (!mac_proc_enforce ||
 466             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 467                 return (0);
 468
 469         cred = kauth_cred_proc_ref(curp);
 470         MAC_CHECK(proc_check_wait, cred, proc);
 471         kauth_cred_unref(&cred);
 472
 473         return (error);
 474 }
 475
 476 #if CONFIG_LCTX
 477 /*
 478  * Login Context
 479  */
 480
 481 int
 482 mac_proc_check_setlcid (struct proc *p0, struct proc *p,
 483                         pid_t pid, pid_t lcid)
 484 {
 485         int error;
 486
 487         if (!mac_proc_enforce ||
 488             !mac_proc_check_enforce(p0, MAC_PROC_ENFORCE))
 489                 return (0);
 490
 491         MAC_CHECK(proc_check_setlcid, p0, p, pid, lcid);
 492         return (error);
 493 }
 494
 495 int
 496 mac_proc_check_getlcid (struct proc *p0, struct proc *p, pid_t pid)
 497 {
 498         int error;
 499
 500         if (!mac_proc_enforce ||
 501             !mac_proc_check_enforce(p0, MAC_PROC_ENFORCE))
 502                 return (0);
 503
 504         MAC_CHECK(proc_check_getlcid, p0, p, pid);
 505         return (error);
 506 }
 507
 508 void
 509 mac_lctx_notify_create (struct proc *p, struct lctx *l)
 510 {
 511         MAC_PERFORM(lctx_notify_create, p, l);
 512 }
 513
 514 void
 515 mac_lctx_notify_join (struct proc *p, struct lctx *l)
 516 {
 517         MAC_PERFORM(lctx_notify_join, p, l);
 518 }
 519
 520 void
 521 mac_lctx_notify_leave (struct proc *p, struct lctx *l)
 522 {
 523         MAC_PERFORM(lctx_notify_leave, p, l);
 524 }
 525
 526 struct label *
 527 mac_lctx_label_alloc(void)
 528 {
 529         struct label *label;
 530
 531         label = mac_labelzone_alloc(MAC_WAITOK);
 532         if (label == NULL)
 533                 return (NULL);
 534         MAC_PERFORM(lctx_label_init, label);
 535         return (label);
 536 }
 537
 538 void
 539 mac_lctx_label_free(struct label *label)
 540 {
 541
 542         MAC_PERFORM(lctx_label_destroy, label);
 543         mac_labelzone_free(label);
 544 }
 545
 546 int
 547 mac_lctx_label_externalize(struct label *label, char *elements,
 548     char *outbuf, size_t outbuflen)
 549 {
 550         int error;
 551
 552         error = MAC_EXTERNALIZE(lctx, label, elements, outbuf, outbuflen);
 553
 554         return (error);
 555 }
 556
 557 int
 558 mac_lctx_label_internalize(struct label *label, char *string)
 559 {
 560         int error;
 561
 562         error = MAC_INTERNALIZE(lctx, label, string);
 563
 564         return (error);
 565 }
 566
 567 void
 568 mac_lctx_label_update(struct lctx *l, struct label *newlabel)
 569 {
 570
 571         MAC_PERFORM(lctx_label_update, l, newlabel);
 572 }
 573
 574 int
 575 mac_lctx_check_label_update(struct lctx *l, struct label *newlabel)
 576 {
 577         int error;
 578
 579         MAC_CHECK(lctx_check_label_update, l, newlabel);
 580
 581         return (error);
 582 }
 583 #endif  /* LCTX */
 584
 585 int
 586 mac_proc_check_suspend_resume(proc_t curp, int sr)
 587 {
 588         kauth_cred_t cred;
 589         int error;
 590
 591         if (!mac_proc_enforce ||
 592             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 593                 return (0);
 594
 595         cred = kauth_cred_proc_ref(curp);
 596         MAC_CHECK(proc_check_suspend_resume, cred, curp, sr);
 597         kauth_cred_unref(&cred);
 598
 599         return (error);
 600 }
 601
 602 int
 603 mac_proc_check_ledger(proc_t curp, proc_t proc, int ledger_op)
 604 {
 605         kauth_cred_t cred;
 606         int error = 0;
 607
 608         if (!mac_proc_enforce ||
 609             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 610                 return (0);
 611
 612         cred = kauth_cred_proc_ref(curp);
 613         MAC_CHECK(proc_check_ledger, cred, proc, ledger_op);
 614         kauth_cred_unref(&cred);
 615
 616         return (error);
 617 }
 618
 619 int
 620 mac_proc_check_cpumon(proc_t curp)
 621 {
 622         kauth_cred_t cred;
 623         int error = 0;
 624
 625         if (!mac_proc_enforce ||
 626             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 627                 return (0);
 628
 629         cred = kauth_cred_proc_ref(curp);
 630         MAC_CHECK(proc_check_cpumon, cred);
 631         kauth_cred_unref(&cred);
 632
 633         return (error);
 634 }
 635
 636 int
 637 mac_proc_check_proc_info(proc_t curp, proc_t target, int callnum, int flavor)
 638 {
 639         kauth_cred_t cred;
 640         int error = 0;
 641
 642         if (!mac_proc_enforce ||
 643             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 644                 return (0);
 645
 646         cred = kauth_cred_proc_ref(curp);
 647         MAC_CHECK(proc_check_proc_info, cred, target, callnum, flavor);
 648         kauth_cred_unref(&cred);
 649
 650         return (error);
 651 }
 652
 653 struct label *
 654 mac_thread_label_alloc(void)
 655 {
 656         struct label *label;
 657
 658         label = mac_labelzone_alloc(MAC_WAITOK);
 659         if (label == NULL)
 660                 return (NULL);
 661         MAC_PERFORM(thread_label_init, label);
 662         return (label);
 663 }
 664
 665 void
 666 mac_thread_label_init(struct uthread *uthread)
 667 {
 668         uthread->uu_label = mac_thread_label_alloc();
 669 }
 670
 671 void
 672 mac_thread_label_free(struct label *label)
 673 {
 674         MAC_PERFORM(thread_label_destroy, label);
 675         mac_labelzone_free(label);
 676 }
 677
 678 void
 679 mac_thread_label_destroy(struct uthread *uthread)
 680 {
 681
 682         mac_thread_label_free(uthread->uu_label);
 683         uthread->uu_label = NULL;
 684 }
 685
 686 void
 687 mac_thread_userret(struct thread *td)
 688 {
 689
 690         MAC_PERFORM(thread_userret, td);
 691 }
 692
 693 struct label *
 694 mac_thread_get_uthreadlabel(struct uthread *uthread)
 695 {
 696
 697         return (uthread->uu_label);
 698 }
 699
 700 struct label *
 701 mac_thread_get_threadlabel(struct thread *thread)
 702 {
 703         struct uthread *uthread = get_bsdthread_info(thread);
 704
 705         return (mac_thread_get_uthreadlabel(uthread));
 706 }