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 int
 367 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)
 368 {
 369         int error;
 370
 371         MAC_CHECK(proc_check_inherit_ipc_ports, p, cur_vp, cur_offset, img_vp, img_offset, scriptvp);
 372
 373         return (error);
 374 }
 375
 376 /*
 377  * The type of maxprot in proc_check_map_anon must be equivalent to vm_prot_t
 378  * (defined in <mach/vm_prot.h>). mac_policy.h does not include any header
 379  * files, so cannot use the typedef itself.
 380  */
 381 int
 382 mac_proc_check_map_anon(proc_t proc, user_addr_t u_addr,
 383     user_size_t u_size, int prot, int flags, int *maxprot)
 384 {
 385         kauth_cred_t cred;
 386         int error;
 387
 388         if (!mac_vm_enforce ||
 389             !mac_proc_check_enforce(proc, MAC_VM_ENFORCE))
 390                 return (0);
 391
 392         cred = kauth_cred_proc_ref(proc);
 393         MAC_CHECK(proc_check_map_anon, proc, cred, u_addr, u_size, prot, flags, maxprot);
 394         kauth_cred_unref(&cred);
 395
 396         return (error);
 397 }
 398
 399 int
 400 mac_proc_check_mprotect(proc_t proc,
 401     user_addr_t addr, user_size_t size, int prot)
 402 {
 403         kauth_cred_t cred;
 404         int error;
 405
 406         if (!mac_vm_enforce ||
 407             !mac_proc_check_enforce(proc, MAC_VM_ENFORCE))
 408                 return (0);
 409
 410         cred = kauth_cred_proc_ref(proc);
 411         MAC_CHECK(proc_check_mprotect, cred, proc, addr, size, prot);
 412         kauth_cred_unref(&cred);
 413
 414         return (error);
 415 }
 416
 417 int
 418 mac_proc_check_run_cs_invalid(proc_t proc)
 419 {
 420         int error;
 421
 422         if (!mac_vm_enforce) return (0);
 423
 424         MAC_CHECK(proc_check_run_cs_invalid, proc);
 425
 426         return (error);
 427 }
 428
 429 int
 430 mac_proc_check_sched(proc_t curp, struct proc *proc)
 431 {
 432         kauth_cred_t cred;
 433         int error;
 434
 435
 436
 437         if (!mac_proc_enforce ||
 438             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 439                 return (0);
 440
 441         cred = kauth_cred_proc_ref(curp);
 442         MAC_CHECK(proc_check_sched, cred, proc);
 443         kauth_cred_unref(&cred);
 444
 445         return (error);
 446 }
 447
 448 int
 449 mac_proc_check_signal(proc_t curp, struct proc *proc, int signum)
 450 {
 451         kauth_cred_t cred;
 452         int error;
 453
 454
 455
 456         if (!mac_proc_enforce ||
 457             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 458                 return (0);
 459
 460         cred = kauth_cred_proc_ref(curp);
 461         MAC_CHECK(proc_check_signal, cred, proc, signum);
 462         kauth_cred_unref(&cred);
 463
 464         return (error);
 465 }
 466
 467 int
 468 mac_proc_check_wait(proc_t curp, struct proc *proc)
 469 {
 470         kauth_cred_t cred;
 471         int error;
 472
 473
 474
 475         if (!mac_proc_enforce ||
 476             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 477                 return (0);
 478
 479         cred = kauth_cred_proc_ref(curp);
 480         MAC_CHECK(proc_check_wait, cred, proc);
 481         kauth_cred_unref(&cred);
 482
 483         return (error);
 484 }
 485
 486 #if CONFIG_LCTX
 487 /*
 488  * Login Context
 489  */
 490
 491 int
 492 mac_proc_check_setlcid (struct proc *p0, struct proc *p,
 493                         pid_t pid, pid_t lcid)
 494 {
 495         int error;
 496
 497         if (!mac_proc_enforce ||
 498             !mac_proc_check_enforce(p0, MAC_PROC_ENFORCE))
 499                 return (0);
 500
 501         MAC_CHECK(proc_check_setlcid, p0, p, pid, lcid);
 502         return (error);
 503 }
 504
 505 int
 506 mac_proc_check_getlcid (struct proc *p0, struct proc *p, pid_t pid)
 507 {
 508         int error;
 509
 510         if (!mac_proc_enforce ||
 511             !mac_proc_check_enforce(p0, MAC_PROC_ENFORCE))
 512                 return (0);
 513
 514         MAC_CHECK(proc_check_getlcid, p0, p, pid);
 515         return (error);
 516 }
 517
 518 void
 519 mac_lctx_notify_create (struct proc *p, struct lctx *l)
 520 {
 521         MAC_PERFORM(lctx_notify_create, p, l);
 522 }
 523
 524 void
 525 mac_lctx_notify_join (struct proc *p, struct lctx *l)
 526 {
 527         MAC_PERFORM(lctx_notify_join, p, l);
 528 }
 529
 530 void
 531 mac_lctx_notify_leave (struct proc *p, struct lctx *l)
 532 {
 533         MAC_PERFORM(lctx_notify_leave, p, l);
 534 }
 535
 536 struct label *
 537 mac_lctx_label_alloc(void)
 538 {
 539         struct label *label;
 540
 541         label = mac_labelzone_alloc(MAC_WAITOK);
 542         if (label == NULL)
 543                 return (NULL);
 544         MAC_PERFORM(lctx_label_init, label);
 545         return (label);
 546 }
 547
 548 void
 549 mac_lctx_label_free(struct label *label)
 550 {
 551
 552         MAC_PERFORM(lctx_label_destroy, label);
 553         mac_labelzone_free(label);
 554 }
 555
 556 int
 557 mac_lctx_label_externalize(struct label *label, char *elements,
 558     char *outbuf, size_t outbuflen)
 559 {
 560         int error;
 561
 562         error = MAC_EXTERNALIZE(lctx, label, elements, outbuf, outbuflen);
 563
 564         return (error);
 565 }
 566
 567 int
 568 mac_lctx_label_internalize(struct label *label, char *string)
 569 {
 570         int error;
 571
 572         error = MAC_INTERNALIZE(lctx, label, string);
 573
 574         return (error);
 575 }
 576
 577 void
 578 mac_lctx_label_update(struct lctx *l, struct label *newlabel)
 579 {
 580
 581         MAC_PERFORM(lctx_label_update, l, newlabel);
 582 }
 583
 584 int
 585 mac_lctx_check_label_update(struct lctx *l, struct label *newlabel)
 586 {
 587         int error;
 588
 589         MAC_CHECK(lctx_check_label_update, l, newlabel);
 590
 591         return (error);
 592 }
 593 #endif  /* LCTX */
 594
 595 int
 596 mac_proc_check_suspend_resume(proc_t curp, int sr)
 597 {
 598         kauth_cred_t cred;
 599         int error;
 600
 601         if (!mac_proc_enforce ||
 602             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 603                 return (0);
 604
 605         cred = kauth_cred_proc_ref(curp);
 606         MAC_CHECK(proc_check_suspend_resume, cred, curp, sr);
 607         kauth_cred_unref(&cred);
 608
 609         return (error);
 610 }
 611
 612 int
 613 mac_proc_check_ledger(proc_t curp, proc_t proc, int ledger_op)
 614 {
 615         kauth_cred_t cred;
 616         int error = 0;
 617
 618         if (!mac_proc_enforce ||
 619             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 620                 return (0);
 621
 622         cred = kauth_cred_proc_ref(curp);
 623         MAC_CHECK(proc_check_ledger, cred, proc, ledger_op);
 624         kauth_cred_unref(&cred);
 625
 626         return (error);
 627 }
 628
 629 int
 630 mac_proc_check_cpumon(proc_t curp)
 631 {
 632         kauth_cred_t cred;
 633         int error = 0;
 634
 635         if (!mac_proc_enforce ||
 636             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 637                 return (0);
 638
 639         cred = kauth_cred_proc_ref(curp);
 640         MAC_CHECK(proc_check_cpumon, cred);
 641         kauth_cred_unref(&cred);
 642
 643         return (error);
 644 }
 645
 646 int
 647 mac_proc_check_proc_info(proc_t curp, proc_t target, int callnum, int flavor)
 648 {
 649         kauth_cred_t cred;
 650         int error = 0;
 651
 652         if (!mac_proc_enforce ||
 653             !mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 654                 return (0);
 655
 656         cred = kauth_cred_proc_ref(curp);
 657         MAC_CHECK(proc_check_proc_info, cred, target, callnum, flavor);
 658         kauth_cred_unref(&cred);
 659
 660         return (error);
 661 }
 662
 663 struct label *
 664 mac_thread_label_alloc(void)
 665 {
 666         struct label *label;
 667
 668         label = mac_labelzone_alloc(MAC_WAITOK);
 669         if (label == NULL)
 670                 return (NULL);
 671         MAC_PERFORM(thread_label_init, label);
 672         return (label);
 673 }
 674
 675 void
 676 mac_thread_label_init(struct uthread *uthread)
 677 {
 678         uthread->uu_label = mac_thread_label_alloc();
 679 }
 680
 681 void
 682 mac_thread_label_free(struct label *label)
 683 {
 684         MAC_PERFORM(thread_label_destroy, label);
 685         mac_labelzone_free(label);
 686 }
 687
 688 void
 689 mac_thread_label_destroy(struct uthread *uthread)
 690 {
 691
 692         mac_thread_label_free(uthread->uu_label);
 693         uthread->uu_label = NULL;
 694 }
 695
 696 void
 697 mac_thread_userret(struct thread *td)
 698 {
 699
 700         MAC_PERFORM(thread_userret, td);
 701 }
 702
 703 struct label *
 704 mac_thread_get_uthreadlabel(struct uthread *uthread)
 705 {
 706
 707         return (uthread->uu_label);
 708 }
 709
 710 struct label *
 711 mac_thread_get_threadlabel(struct thread *thread)
 712 {
 713         struct uthread *uthread = get_bsdthread_info(thread);
 714
 715         return (mac_thread_get_uthreadlabel(uthread));
 716 }