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         MAC_PERFORM(cred_label_init, label);
  92         return (label);
  93 }
  94
  95 void
  96 mac_cred_label_init(struct ucred *cred)
  97 {
  98         cred->cr_label = mac_cred_label_alloc();
  99 }
 100
 101 void
 102 mac_cred_label_free(struct label *label)
 103 {
 104         MAC_PERFORM(cred_label_destroy, label);
 105         mac_labelzone_free(label);
 106 }
 107
 108 int
 109 mac_cred_label_compare(struct label *a, struct label *b)
 110 {
 111         return (bcmp(a, b, sizeof (*a)) == 0);
 112 }
 113
 114 int
 115 mac_cred_label_externalize_audit(struct proc *p, struct mac *mac)
 116 {
 117         kauth_cred_t cr;
 118         int error;
 119
 120         cr = kauth_cred_proc_ref(p);
 121
 122         error = MAC_EXTERNALIZE_AUDIT(cred, cr->cr_label,
 123             mac->m_string, mac->m_buflen);
 124
 125         kauth_cred_unref(&cr);
 126         return (error);
 127 }
 128
 129 void
 130 mac_cred_label_destroy(kauth_cred_t cred)
 131 {
 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
 178         MAC_PERFORM(cred_label_associate_kernel, cred);
 179 }
 180
 181 /*
 182  * Initialize MAC label for the first userland process, from which other
 183  * userland processes and threads are spawned.
 184  */
 185 void
 186 mac_cred_label_associate_user(kauth_cred_t cred)
 187 {
 188
 189         MAC_PERFORM(cred_label_associate_user, cred);
 190 }
 191
 192 /*
 193  * When a new process is created, its label must be initialized.  Generally,
 194  * this involves inheritence from the parent process, modulo possible
 195  * deltas.  This function allows that processing to take place.
 196  */
 197 void
 198 mac_cred_label_associate(struct ucred *parent_cred, struct ucred *child_cred)
 199 {
 200
 201         MAC_PERFORM(cred_label_associate, parent_cred, child_cred);
 202 }
 203
 204 int
 205 mac_execve_enter(user_addr_t mac_p, struct image_params *imgp)
 206 {
 207         struct user_mac mac;
 208         struct label *execlabel;
 209         char *buffer;
 210         int error;
 211         size_t ulen;
 212
 213         if (mac_p == USER_ADDR_NULL)
 214                 return (0);
 215
 216         if (IS_64BIT_PROCESS(current_proc())) {
 217                 struct user64_mac mac64;
 218                 error = copyin(mac_p, &mac64, sizeof(mac64));
 219                 mac.m_buflen = mac64.m_buflen;
 220                 mac.m_string = mac64.m_string;
 221         } else {
 222                 struct user32_mac mac32;
 223                 error = copyin(mac_p, &mac32, sizeof(mac32));
 224                 mac.m_buflen = mac32.m_buflen;
 225                 mac.m_string = mac32.m_string;
 226         }
 227         if (error)
 228                 return (error);
 229
 230         error = mac_check_structmac_consistent(&mac);
 231         if (error)
 232                 return (error);
 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         AUDIT_ARG(mac_string, buffer);
 240
 241         error = mac_cred_label_internalize(execlabel, buffer);
 242 out:
 243         if (error) {
 244                 mac_cred_label_free(execlabel);
 245                 execlabel = NULL;
 246         }
 247         imgp->ip_execlabelp = execlabel;
 248         FREE(buffer, M_MACTEMP);
 249         return (error);
 250 }
 251
 252 /*
 253  * When the subject's label changes, it may require revocation of privilege
 254  * to mapped objects.  This can't be done on-the-fly later with a unified
 255  * buffer cache.
 256  *
 257  * XXX:         CRF_MAC_ENFORCE should be in a kauth_cred_t field, rather
 258  * XXX:         than a posix_cred_t field.
 259  */
 260 void
 261 mac_cred_label_update(kauth_cred_t cred, struct label *newlabel)
 262 {
 263         posix_cred_t pcred = posix_cred_get(cred);
 264
 265         /* force label to be part of "matching" for credential */
 266         pcred->cr_flags |= CRF_MAC_ENFORCE;
 267
 268         /* inform the policies of the update */
 269         MAC_PERFORM(cred_label_update, cred, newlabel);
 270 }
 271
 272 int
 273 mac_cred_check_label_update(kauth_cred_t cred, struct label *newlabel)
 274 {
 275         int error;
 276
 277 #if SECURITY_MAC_CHECK_ENFORCE
 278     /* 21167099 - only check if we allow write */
 279     if (!mac_proc_enforce)
 280         return 0;
 281 #endif
 282
 283         MAC_CHECK(cred_check_label_update, cred, newlabel);
 284
 285         return (error);
 286 }
 287
 288 int
 289 mac_cred_check_visible(kauth_cred_t u1, kauth_cred_t u2)
 290 {
 291         int error;
 292
 293 #if SECURITY_MAC_CHECK_ENFORCE
 294         /* 21167099 - only check if we allow write */
 295         if (!mac_proc_enforce)
 296                 return 0;
 297 #endif
 298
 299         MAC_CHECK(cred_check_visible, u1, u2);
 300
 301         return (error);
 302 }
 303
 304 /*
 305  * called with process locked.
 306  */
 307 void mac_proc_set_enforce(proc_t p, int enforce_flags)
 308 {
 309         p->p_mac_enforce |= enforce_flags;
 310 }
 311
 312 int
 313 mac_proc_check_debug(proc_t curp, struct proc *proc)
 314 {
 315         kauth_cred_t cred;
 316         int error;
 317
 318 #if SECURITY_MAC_CHECK_ENFORCE
 319         /* 21167099 - only check if we allow write */
 320         if (!mac_proc_enforce)
 321                 return 0;
 322 #endif
 323         if (!mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 324                 return 0;
 325
 326         cred = kauth_cred_proc_ref(curp);
 327         MAC_CHECK(proc_check_debug, cred, proc);
 328         kauth_cred_unref(&cred);
 329
 330         return (error);
 331 }
 332
 333 int
 334 mac_proc_check_fork(proc_t curp)
 335 {
 336         kauth_cred_t cred;
 337         int error;
 338
 339 #if SECURITY_MAC_CHECK_ENFORCE
 340         /* 21167099 - only check if we allow write */
 341         if (!mac_proc_enforce)
 342                 return 0;
 343 #endif
 344         if (!mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 345                 return 0;
 346
 347         cred = kauth_cred_proc_ref(curp);
 348         MAC_CHECK(proc_check_fork, cred, curp);
 349         kauth_cred_unref(&cred);
 350
 351         return (error);
 352 }
 353
 354 int
 355 mac_proc_check_get_task_name(struct ucred *cred, struct proc *p)
 356 {
 357         int error;
 358
 359         MAC_CHECK(proc_check_get_task_name, cred, p);
 360
 361         return (error);
 362 }
 363
 364 int
 365 mac_proc_check_get_task(struct ucred *cred, struct proc *p)
 366 {
 367         int error;
 368
 369         MAC_CHECK(proc_check_get_task, cred, p);
 370
 371         return (error);
 372 }
 373
 374 int
 375 mac_proc_check_expose_task(struct ucred *cred, struct proc *p)
 376 {
 377         int error;
 378
 379         MAC_CHECK(proc_check_expose_task, cred, p);
 380
 381         return (error);
 382 }
 383
 384 int
 385 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)
 386 {
 387         int error;
 388
 389         MAC_CHECK(proc_check_inherit_ipc_ports, p, cur_vp, cur_offset, img_vp, img_offset, scriptvp);
 390
 391         return (error);
 392 }
 393
 394 /*
 395  * The type of maxprot in proc_check_map_anon must be equivalent to vm_prot_t
 396  * (defined in <mach/vm_prot.h>). mac_policy.h does not include any header
 397  * files, so cannot use the typedef itself.
 398  */
 399 int
 400 mac_proc_check_map_anon(proc_t proc, user_addr_t u_addr,
 401     user_size_t u_size, int prot, int flags, int *maxprot)
 402 {
 403         kauth_cred_t cred;
 404         int error;
 405
 406 #if SECURITY_MAC_CHECK_ENFORCE
 407         /* 21167099 - only check if we allow write */
 408         if (!mac_vm_enforce)
 409                 return 0;
 410 #endif
 411         if (!mac_proc_check_enforce(proc, MAC_VM_ENFORCE))
 412                 return (0);
 413
 414         cred = kauth_cred_proc_ref(proc);
 415         MAC_CHECK(proc_check_map_anon, proc, cred, u_addr, u_size, prot, flags, maxprot);
 416         kauth_cred_unref(&cred);
 417
 418         return (error);
 419 }
 420
 421 int
 422 mac_proc_check_mprotect(proc_t proc,
 423     user_addr_t addr, user_size_t size, int prot)
 424 {
 425         kauth_cred_t cred;
 426         int error;
 427
 428 #if SECURITY_MAC_CHECK_ENFORCE
 429         /* 21167099 - only check if we allow write */
 430         if (!mac_vm_enforce)
 431                 return 0;
 432 #endif
 433         if (!mac_proc_check_enforce(proc, MAC_VM_ENFORCE))
 434                 return (0);
 435
 436         cred = kauth_cred_proc_ref(proc);
 437         MAC_CHECK(proc_check_mprotect, cred, proc, addr, size, prot);
 438         kauth_cred_unref(&cred);
 439
 440         return (error);
 441 }
 442
 443 int
 444 mac_proc_check_run_cs_invalid(proc_t proc)
 445 {
 446         int error;
 447
 448 #if SECURITY_MAC_CHECK_ENFORCE
 449     /* 21167099 - only check if we allow write */
 450     if (!mac_vm_enforce)
 451         return 0;
 452 #endif
 453
 454         MAC_CHECK(proc_check_run_cs_invalid, proc);
 455
 456         return (error);
 457 }
 458
 459 int
 460 mac_proc_check_sched(proc_t curp, struct proc *proc)
 461 {
 462         kauth_cred_t cred;
 463         int error;
 464
 465 #if SECURITY_MAC_CHECK_ENFORCE
 466         /* 21167099 - only check if we allow write */
 467         if (!mac_proc_enforce)
 468                 return 0;
 469 #endif
 470         if (!mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 471                 return 0;
 472
 473         cred = kauth_cred_proc_ref(curp);
 474         MAC_CHECK(proc_check_sched, cred, proc);
 475         kauth_cred_unref(&cred);
 476
 477         return (error);
 478 }
 479
 480 int
 481 mac_proc_check_signal(proc_t curp, struct proc *proc, int signum)
 482 {
 483         kauth_cred_t cred;
 484         int error;
 485
 486 #if SECURITY_MAC_CHECK_ENFORCE
 487         /* 21167099 - only check if we allow write */
 488         if (!mac_proc_enforce)
 489                 return 0;
 490 #endif
 491         if (!mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 492                 return 0;
 493
 494         cred = kauth_cred_proc_ref(curp);
 495         MAC_CHECK(proc_check_signal, cred, proc, signum);
 496         kauth_cred_unref(&cred);
 497
 498         return (error);
 499 }
 500
 501 int
 502 mac_proc_check_wait(proc_t curp, struct proc *proc)
 503 {
 504         kauth_cred_t cred;
 505         int error;
 506
 507 #if SECURITY_MAC_CHECK_ENFORCE
 508         /* 21167099 - only check if we allow write */
 509         if (!mac_proc_enforce)
 510                 return 0;
 511 #endif
 512         if (!mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 513                 return 0;
 514
 515         cred = kauth_cred_proc_ref(curp);
 516         MAC_CHECK(proc_check_wait, cred, proc);
 517         kauth_cred_unref(&cred);
 518
 519         return (error);
 520 }
 521
 522 int
 523 mac_proc_check_suspend_resume(proc_t curp, int sr)
 524 {
 525         kauth_cred_t cred;
 526         int error;
 527
 528 #if SECURITY_MAC_CHECK_ENFORCE
 529         /* 21167099 - only check if we allow write */
 530         if (!mac_proc_enforce)
 531                 return 0;
 532 #endif
 533         if (!mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 534                 return 0;
 535
 536         cred = kauth_cred_proc_ref(curp);
 537         MAC_CHECK(proc_check_suspend_resume, cred, curp, sr);
 538         kauth_cred_unref(&cred);
 539
 540         return (error);
 541 }
 542
 543 int
 544 mac_proc_check_ledger(proc_t curp, proc_t proc, int ledger_op)
 545 {
 546         kauth_cred_t cred;
 547         int error = 0;
 548
 549 #if SECURITY_MAC_CHECK_ENFORCE
 550         /* 21167099 - only check if we allow write */
 551         if (!mac_proc_enforce)
 552                 return 0;
 553 #endif
 554         if (!mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 555                 return 0;
 556
 557         cred = kauth_cred_proc_ref(curp);
 558         MAC_CHECK(proc_check_ledger, cred, proc, ledger_op);
 559         kauth_cred_unref(&cred);
 560
 561         return (error);
 562 }
 563
 564 int
 565 mac_proc_check_cpumon(proc_t curp)
 566 {
 567         kauth_cred_t cred;
 568         int error = 0;
 569
 570 #if SECURITY_MAC_CHECK_ENFORCE
 571         /* 21167099 - only check if we allow write */
 572         if (!mac_proc_enforce)
 573                 return 0;
 574 #endif
 575         if (!mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 576                 return 0;
 577
 578         cred = kauth_cred_proc_ref(curp);
 579         MAC_CHECK(proc_check_cpumon, cred);
 580         kauth_cred_unref(&cred);
 581
 582         return (error);
 583 }
 584
 585 int
 586 mac_proc_check_proc_info(proc_t curp, proc_t target, int callnum, int flavor)
 587 {
 588         kauth_cred_t cred;
 589         int error = 0;
 590
 591 #if SECURITY_MAC_CHECK_ENFORCE
 592         /* 21167099 - only check if we allow write */
 593         if (!mac_proc_enforce)
 594                 return 0;
 595 #endif
 596         if (!mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 597                 return 0;
 598
 599         cred = kauth_cred_proc_ref(curp);
 600         MAC_CHECK(proc_check_proc_info, cred, target, callnum, flavor);
 601         kauth_cred_unref(&cred);
 602
 603         return (error);
 604 }
 605
 606 int
 607 mac_proc_check_get_cs_info(proc_t curp, proc_t target, unsigned int op)
 608 {
 609         kauth_cred_t cred;
 610         int error = 0;
 611
 612 #if SECURITY_MAC_CHECK_ENFORCE
 613         /* 21167099 - only check if we allow write */
 614         if (!mac_proc_enforce)
 615                 return 0;
 616 #endif
 617         if (!mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 618                 return 0;
 619
 620         cred = kauth_cred_proc_ref(curp);
 621         MAC_CHECK(proc_check_get_cs_info, cred, target, op);
 622         kauth_cred_unref(&cred);
 623
 624         return (error);
 625 }
 626
 627 int
 628 mac_proc_check_set_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 #endif
 638         if (!mac_proc_check_enforce(curp, MAC_PROC_ENFORCE))
 639                 return 0;
 640
 641         cred = kauth_cred_proc_ref(curp);
 642         MAC_CHECK(proc_check_set_cs_info, cred, target, op);
 643         kauth_cred_unref(&cred);
 644
 645         return (error);
 646 }
 647