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 int
 305 mac_proc_check_debug(proc_t curp, struct proc *proc)
 306 {
 307         kauth_cred_t cred;
 308         int error;
 309
 310 #if SECURITY_MAC_CHECK_ENFORCE
 311         /* 21167099 - only check if we allow write */
 312         if (!mac_proc_enforce)
 313                 return 0;
 314 #endif
 315         if (!mac_proc_check_enforce(curp))
 316                 return 0;
 317
 318         cred = kauth_cred_proc_ref(curp);
 319         MAC_CHECK(proc_check_debug, cred, proc);
 320         kauth_cred_unref(&cred);
 321
 322         return (error);
 323 }
 324
 325 int
 326 mac_proc_check_fork(proc_t curp)
 327 {
 328         kauth_cred_t cred;
 329         int error;
 330
 331 #if SECURITY_MAC_CHECK_ENFORCE
 332         /* 21167099 - only check if we allow write */
 333         if (!mac_proc_enforce)
 334                 return 0;
 335 #endif
 336         if (!mac_proc_check_enforce(curp))
 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_expose_task(struct ucred *cred, struct proc *p)
 368 {
 369         int error;
 370
 371         MAC_CHECK(proc_check_expose_task, cred, p);
 372
 373         return (error);
 374 }
 375
 376 int
 377 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)
 378 {
 379         int error;
 380
 381         MAC_CHECK(proc_check_inherit_ipc_ports, p, cur_vp, cur_offset, img_vp, img_offset, scriptvp);
 382
 383         return (error);
 384 }
 385
 386 /*
 387  * The type of maxprot in proc_check_map_anon must be equivalent to vm_prot_t
 388  * (defined in <mach/vm_prot.h>). mac_policy.h does not include any header
 389  * files, so cannot use the typedef itself.
 390  */
 391 int
 392 mac_proc_check_map_anon(proc_t proc, user_addr_t u_addr,
 393     user_size_t u_size, int prot, int flags, int *maxprot)
 394 {
 395         kauth_cred_t cred;
 396         int error;
 397
 398 #if SECURITY_MAC_CHECK_ENFORCE
 399         /* 21167099 - only check if we allow write */
 400         if (!mac_vm_enforce)
 401                 return 0;
 402 #endif
 403         if (!mac_proc_check_enforce(proc))
 404                 return (0);
 405
 406         cred = kauth_cred_proc_ref(proc);
 407         MAC_CHECK(proc_check_map_anon, proc, cred, u_addr, u_size, prot, flags, maxprot);
 408         kauth_cred_unref(&cred);
 409
 410         return (error);
 411 }
 412
 413 int
 414 mac_proc_check_mprotect(proc_t proc,
 415     user_addr_t addr, user_size_t size, int prot)
 416 {
 417         kauth_cred_t cred;
 418         int error;
 419
 420 #if SECURITY_MAC_CHECK_ENFORCE
 421         /* 21167099 - only check if we allow write */
 422         if (!mac_vm_enforce)
 423                 return 0;
 424 #endif
 425         if (!mac_proc_check_enforce(proc))
 426                 return (0);
 427
 428         cred = kauth_cred_proc_ref(proc);
 429         MAC_CHECK(proc_check_mprotect, cred, proc, addr, size, prot);
 430         kauth_cred_unref(&cred);
 431
 432         return (error);
 433 }
 434
 435 int
 436 mac_proc_check_run_cs_invalid(proc_t proc)
 437 {
 438         int error;
 439
 440 #if SECURITY_MAC_CHECK_ENFORCE
 441     /* 21167099 - only check if we allow write */
 442     if (!mac_vm_enforce)
 443         return 0;
 444 #endif
 445
 446         MAC_CHECK(proc_check_run_cs_invalid, proc);
 447
 448         return (error);
 449 }
 450
 451 int
 452 mac_proc_check_sched(proc_t curp, struct proc *proc)
 453 {
 454         kauth_cred_t cred;
 455         int error;
 456
 457 #if SECURITY_MAC_CHECK_ENFORCE
 458         /* 21167099 - only check if we allow write */
 459         if (!mac_proc_enforce)
 460                 return 0;
 461 #endif
 462         if (!mac_proc_check_enforce(curp))
 463                 return 0;
 464
 465         cred = kauth_cred_proc_ref(curp);
 466         MAC_CHECK(proc_check_sched, cred, proc);
 467         kauth_cred_unref(&cred);
 468
 469         return (error);
 470 }
 471
 472 int
 473 mac_proc_check_signal(proc_t curp, struct proc *proc, int signum)
 474 {
 475         kauth_cred_t cred;
 476         int error;
 477
 478 #if SECURITY_MAC_CHECK_ENFORCE
 479         /* 21167099 - only check if we allow write */
 480         if (!mac_proc_enforce)
 481                 return 0;
 482 #endif
 483         if (!mac_proc_check_enforce(curp))
 484                 return 0;
 485
 486         cred = kauth_cred_proc_ref(curp);
 487         MAC_CHECK(proc_check_signal, cred, proc, signum);
 488         kauth_cred_unref(&cred);
 489
 490         return (error);
 491 }
 492
 493 int
 494 mac_proc_check_wait(proc_t curp, struct proc *proc)
 495 {
 496         kauth_cred_t cred;
 497         int error;
 498
 499 #if SECURITY_MAC_CHECK_ENFORCE
 500         /* 21167099 - only check if we allow write */
 501         if (!mac_proc_enforce)
 502                 return 0;
 503 #endif
 504         if (!mac_proc_check_enforce(curp))
 505                 return 0;
 506
 507         cred = kauth_cred_proc_ref(curp);
 508         MAC_CHECK(proc_check_wait, cred, proc);
 509         kauth_cred_unref(&cred);
 510
 511         return (error);
 512 }
 513
 514 void
 515 mac_proc_notify_exit(struct proc *proc)
 516 {
 517         MAC_PERFORM(proc_notify_exit, proc);
 518 }
 519
 520 int
 521 mac_proc_check_suspend_resume(proc_t curp, int sr)
 522 {
 523         kauth_cred_t cred;
 524         int error;
 525
 526 #if SECURITY_MAC_CHECK_ENFORCE
 527         /* 21167099 - only check if we allow write */
 528         if (!mac_proc_enforce)
 529                 return 0;
 530 #endif
 531         if (!mac_proc_check_enforce(curp))
 532                 return 0;
 533
 534         cred = kauth_cred_proc_ref(curp);
 535         MAC_CHECK(proc_check_suspend_resume, cred, curp, sr);
 536         kauth_cred_unref(&cred);
 537
 538         return (error);
 539 }
 540
 541 int
 542 mac_proc_check_ledger(proc_t curp, proc_t proc, int ledger_op)
 543 {
 544         kauth_cred_t cred;
 545         int error = 0;
 546
 547 #if SECURITY_MAC_CHECK_ENFORCE
 548         /* 21167099 - only check if we allow write */
 549         if (!mac_proc_enforce)
 550                 return 0;
 551 #endif
 552         if (!mac_proc_check_enforce(curp))
 553                 return 0;
 554
 555         cred = kauth_cred_proc_ref(curp);
 556         MAC_CHECK(proc_check_ledger, cred, proc, ledger_op);
 557         kauth_cred_unref(&cred);
 558
 559         return (error);
 560 }
 561
 562 int
 563 mac_proc_check_proc_info(proc_t curp, proc_t target, int callnum, int flavor)
 564 {
 565         kauth_cred_t cred;
 566         int error = 0;
 567
 568 #if SECURITY_MAC_CHECK_ENFORCE
 569         /* 21167099 - only check if we allow write */
 570         if (!mac_proc_enforce)
 571                 return 0;
 572 #endif
 573         if (!mac_proc_check_enforce(curp))
 574                 return 0;
 575
 576         cred = kauth_cred_proc_ref(curp);
 577         MAC_CHECK(proc_check_proc_info, cred, target, callnum, flavor);
 578         kauth_cred_unref(&cred);
 579
 580         return (error);
 581 }
 582
 583 int
 584 mac_proc_check_get_cs_info(proc_t curp, proc_t target, unsigned int op)
 585 {
 586         kauth_cred_t cred;
 587         int error = 0;
 588
 589 #if SECURITY_MAC_CHECK_ENFORCE
 590         /* 21167099 - only check if we allow write */
 591         if (!mac_proc_enforce)
 592                 return 0;
 593 #endif
 594         if (!mac_proc_check_enforce(curp))
 595                 return 0;
 596
 597         cred = kauth_cred_proc_ref(curp);
 598         MAC_CHECK(proc_check_get_cs_info, cred, target, op);
 599         kauth_cred_unref(&cred);
 600
 601         return (error);
 602 }
 603
 604 int
 605 mac_proc_check_set_cs_info(proc_t curp, proc_t target, unsigned int op)
 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 #endif
 615         if (!mac_proc_check_enforce(curp))
 616                 return 0;
 617
 618         cred = kauth_cred_proc_ref(curp);
 619         MAC_CHECK(proc_check_set_cs_info, cred, target, op);
 620         kauth_cred_unref(&cred);
 621
 622         return (error);
 623 }
 624