1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1999-2005 Apple Inc. 5 * Copyright (c) 2006-2007, 2016-2017 Robert N. M. Watson 6 * All rights reserved. 7 * 8 * Portions of this software were developed by BAE Systems, the University of 9 * Cambridge Computer Laboratory, and Memorial University under DARPA/AFRL 10 * contract FA8650-15-C-7558 ("CADETS"), as part of the DARPA Transparent 11 * Computing (TC) research program. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. Neither the name of Apple Inc. ("Apple") nor the names of 22 * its contributors may be used to endorse or promote products derived 23 * from this software without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR 29 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 33 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 34 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35 * POSSIBILITY OF SUCH DAMAGE. 36 */ 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <sys/param.h> 42 #include <sys/condvar.h> 43 #include <sys/conf.h> 44 #include <sys/file.h> 45 #include <sys/filedesc.h> 46 #include <sys/fcntl.h> 47 #include <sys/ipc.h> 48 #include <sys/jail.h> 49 #include <sys/kernel.h> 50 #include <sys/kthread.h> 51 #include <sys/malloc.h> 52 #include <sys/mount.h> 53 #include <sys/namei.h> 54 #include <sys/priv.h> 55 #include <sys/proc.h> 56 #include <sys/queue.h> 57 #include <sys/socket.h> 58 #include <sys/socketvar.h> 59 #include <sys/protosw.h> 60 #include <sys/domain.h> 61 #include <sys/sysctl.h> 62 #include <sys/sysproto.h> 63 #include <sys/sysent.h> 64 #include <sys/systm.h> 65 #include <sys/ucred.h> 66 #include <sys/uio.h> 67 #include <sys/un.h> 68 #include <sys/unistd.h> 69 #include <sys/vnode.h> 70 71 #include <bsm/audit.h> 72 #include <bsm/audit_internal.h> 73 #include <bsm/audit_kevents.h> 74 75 #include <netinet/in.h> 76 #include <netinet/in_pcb.h> 77 78 #include <security/audit/audit.h> 79 #include <security/audit/audit_private.h> 80 81 #include <vm/uma.h> 82 83 FEATURE(audit, "BSM audit support"); 84 85 static uma_zone_t audit_record_zone; 86 static MALLOC_DEFINE(M_AUDITCRED, "audit_cred", "Audit cred storage"); 87 MALLOC_DEFINE(M_AUDITDATA, "audit_data", "Audit data storage"); 88 MALLOC_DEFINE(M_AUDITPATH, "audit_path", "Audit path storage"); 89 MALLOC_DEFINE(M_AUDITTEXT, "audit_text", "Audit text storage"); 90 MALLOC_DEFINE(M_AUDITGIDSET, "audit_gidset", "Audit GID set storage"); 91 92 static SYSCTL_NODE(_security, OID_AUTO, audit, CTLFLAG_RW, 0, 93 "TrustedBSD audit controls"); 94 95 /* 96 * Audit control settings that are set/read by system calls and are hence 97 * non-static. 98 * 99 * Define the audit control flags. 100 */ 101 int __read_frequently audit_enabled; 102 int audit_suspended; 103 104 /* 105 * Flags controlling behavior in low storage situations. Should we panic if 106 * a write fails? Should we fail stop if we're out of disk space? 107 */ 108 int audit_panic_on_write_fail; 109 int audit_fail_stop; 110 int audit_argv; 111 int audit_arge; 112 113 /* 114 * Are we currently "failing stop" due to out of disk space? 115 */ 116 int audit_in_failure; 117 118 /* 119 * Global audit statistics. 120 */ 121 struct audit_fstat audit_fstat; 122 123 /* 124 * Preselection mask for non-attributable events. 125 */ 126 struct au_mask audit_nae_mask; 127 128 /* 129 * Mutex to protect global variables shared between various threads and 130 * processes. 131 */ 132 struct mtx audit_mtx; 133 134 /* 135 * Queue of audit records ready for delivery to disk. We insert new records 136 * at the tail, and remove records from the head. Also, a count of the 137 * number of records used for checking queue depth. In addition, a counter 138 * of records that we have allocated but are not yet in the queue, which is 139 * needed to estimate the total size of the combined set of records 140 * outstanding in the system. 141 */ 142 struct kaudit_queue audit_q; 143 int audit_q_len; 144 int audit_pre_q_len; 145 146 /* 147 * Audit queue control settings (minimum free, low/high water marks, etc.) 148 */ 149 struct au_qctrl audit_qctrl; 150 151 /* 152 * Condition variable to signal to the worker that it has work to do: either 153 * new records are in the queue, or a log replacement is taking place. 154 */ 155 struct cv audit_worker_cv; 156 157 /* 158 * Condition variable to flag when crossing the low watermark, meaning that 159 * threads blocked due to hitting the high watermark can wake up and continue 160 * to commit records. 161 */ 162 struct cv audit_watermark_cv; 163 164 /* 165 * Condition variable for auditing threads wait on when in fail-stop mode. 166 * Threads wait on this CV forever (and ever), never seeing the light of day 167 * again. 168 */ 169 static struct cv audit_fail_cv; 170 171 /* 172 * Optional DTrace audit provider support: function pointers for preselection 173 * and commit events. 174 */ 175 #ifdef KDTRACE_HOOKS 176 void *(*dtaudit_hook_preselect)(au_id_t auid, au_event_t event, 177 au_class_t class); 178 int (*dtaudit_hook_commit)(struct kaudit_record *kar, au_id_t auid, 179 au_event_t event, au_class_t class, int sorf); 180 void (*dtaudit_hook_bsm)(struct kaudit_record *kar, au_id_t auid, 181 au_event_t event, au_class_t class, int sorf, 182 void *bsm_data, size_t bsm_lenlen); 183 #endif 184 185 /* 186 * Kernel audit information. This will store the current audit address 187 * or host information that the kernel will use when it's generating 188 * audit records. This data is modified by the A_GET{SET}KAUDIT auditon(2) 189 * command. 190 */ 191 static struct auditinfo_addr audit_kinfo; 192 static struct rwlock audit_kinfo_lock; 193 194 #define KINFO_LOCK_INIT() rw_init(&audit_kinfo_lock, \ 195 "audit_kinfo_lock") 196 #define KINFO_RLOCK() rw_rlock(&audit_kinfo_lock) 197 #define KINFO_WLOCK() rw_wlock(&audit_kinfo_lock) 198 #define KINFO_RUNLOCK() rw_runlock(&audit_kinfo_lock) 199 #define KINFO_WUNLOCK() rw_wunlock(&audit_kinfo_lock) 200 201 void 202 audit_set_kinfo(struct auditinfo_addr *ak) 203 { 204 205 KASSERT(ak->ai_termid.at_type == AU_IPv4 || 206 ak->ai_termid.at_type == AU_IPv6, 207 ("audit_set_kinfo: invalid address type")); 208 209 KINFO_WLOCK(); 210 audit_kinfo = *ak; 211 KINFO_WUNLOCK(); 212 } 213 214 void 215 audit_get_kinfo(struct auditinfo_addr *ak) 216 { 217 218 KASSERT(audit_kinfo.ai_termid.at_type == AU_IPv4 || 219 audit_kinfo.ai_termid.at_type == AU_IPv6, 220 ("audit_set_kinfo: invalid address type")); 221 222 KINFO_RLOCK(); 223 *ak = audit_kinfo; 224 KINFO_RUNLOCK(); 225 } 226 227 /* 228 * Construct an audit record for the passed thread. 229 */ 230 static int 231 audit_record_ctor(void *mem, int size, void *arg, int flags) 232 { 233 struct kaudit_record *ar; 234 struct thread *td; 235 struct ucred *cred; 236 struct prison *pr; 237 238 KASSERT(sizeof(*ar) == size, ("audit_record_ctor: wrong size")); 239 240 td = arg; 241 ar = mem; 242 bzero(ar, sizeof(*ar)); 243 ar->k_ar.ar_magic = AUDIT_RECORD_MAGIC; 244 nanotime(&ar->k_ar.ar_starttime); 245 246 /* 247 * Export the subject credential. 248 */ 249 cred = td->td_ucred; 250 cru2x(cred, &ar->k_ar.ar_subj_cred); 251 ar->k_ar.ar_subj_ruid = cred->cr_ruid; 252 ar->k_ar.ar_subj_rgid = cred->cr_rgid; 253 ar->k_ar.ar_subj_egid = cred->cr_groups[0]; 254 ar->k_ar.ar_subj_auid = cred->cr_audit.ai_auid; 255 ar->k_ar.ar_subj_asid = cred->cr_audit.ai_asid; 256 ar->k_ar.ar_subj_pid = td->td_proc->p_pid; 257 ar->k_ar.ar_subj_amask = cred->cr_audit.ai_mask; 258 ar->k_ar.ar_subj_term_addr = cred->cr_audit.ai_termid; 259 /* 260 * If this process is jailed, make sure we capture the name of the 261 * jail so we can use it to generate a zonename token when we covert 262 * this record to BSM. 263 */ 264 if (jailed(cred)) { 265 pr = cred->cr_prison; 266 (void) strlcpy(ar->k_ar.ar_jailname, pr->pr_name, 267 sizeof(ar->k_ar.ar_jailname)); 268 } else 269 ar->k_ar.ar_jailname[0] = '\0'; 270 return (0); 271 } 272 273 static void 274 audit_record_dtor(void *mem, int size, void *arg) 275 { 276 struct kaudit_record *ar; 277 278 KASSERT(sizeof(*ar) == size, ("audit_record_dtor: wrong size")); 279 280 ar = mem; 281 if (ar->k_ar.ar_arg_upath1 != NULL) 282 free(ar->k_ar.ar_arg_upath1, M_AUDITPATH); 283 if (ar->k_ar.ar_arg_upath2 != NULL) 284 free(ar->k_ar.ar_arg_upath2, M_AUDITPATH); 285 if (ar->k_ar.ar_arg_text != NULL) 286 free(ar->k_ar.ar_arg_text, M_AUDITTEXT); 287 if (ar->k_udata != NULL) 288 free(ar->k_udata, M_AUDITDATA); 289 if (ar->k_ar.ar_arg_argv != NULL) 290 free(ar->k_ar.ar_arg_argv, M_AUDITTEXT); 291 if (ar->k_ar.ar_arg_envv != NULL) 292 free(ar->k_ar.ar_arg_envv, M_AUDITTEXT); 293 if (ar->k_ar.ar_arg_groups.gidset != NULL) 294 free(ar->k_ar.ar_arg_groups.gidset, M_AUDITGIDSET); 295 } 296 297 /* 298 * Initialize the Audit subsystem: configuration state, work queue, 299 * synchronization primitives, worker thread, and trigger device node. Also 300 * call into the BSM assembly code to initialize it. 301 */ 302 static void 303 audit_init(void) 304 { 305 306 audit_enabled = 0; 307 audit_suspended = 0; 308 audit_panic_on_write_fail = 0; 309 audit_fail_stop = 0; 310 audit_in_failure = 0; 311 audit_argv = 0; 312 audit_arge = 0; 313 314 audit_fstat.af_filesz = 0; /* '0' means unset, unbounded. */ 315 audit_fstat.af_currsz = 0; 316 audit_nae_mask.am_success = 0; 317 audit_nae_mask.am_failure = 0; 318 319 TAILQ_INIT(&audit_q); 320 audit_q_len = 0; 321 audit_pre_q_len = 0; 322 audit_qctrl.aq_hiwater = AQ_HIWATER; 323 audit_qctrl.aq_lowater = AQ_LOWATER; 324 audit_qctrl.aq_bufsz = AQ_BUFSZ; 325 audit_qctrl.aq_minfree = AU_FS_MINFREE; 326 327 audit_kinfo.ai_termid.at_type = AU_IPv4; 328 audit_kinfo.ai_termid.at_addr[0] = INADDR_ANY; 329 330 mtx_init(&audit_mtx, "audit_mtx", NULL, MTX_DEF); 331 KINFO_LOCK_INIT(); 332 cv_init(&audit_worker_cv, "audit_worker_cv"); 333 cv_init(&audit_watermark_cv, "audit_watermark_cv"); 334 cv_init(&audit_fail_cv, "audit_fail_cv"); 335 336 audit_record_zone = uma_zcreate("audit_record", 337 sizeof(struct kaudit_record), audit_record_ctor, 338 audit_record_dtor, NULL, NULL, UMA_ALIGN_PTR, 0); 339 340 /* Initialize the BSM audit subsystem. */ 341 kau_init(); 342 343 audit_trigger_init(); 344 345 /* Register shutdown handler. */ 346 EVENTHANDLER_REGISTER(shutdown_pre_sync, audit_shutdown, NULL, 347 SHUTDOWN_PRI_FIRST); 348 349 /* Start audit worker thread. */ 350 audit_worker_init(); 351 } 352 353 SYSINIT(audit_init, SI_SUB_AUDIT, SI_ORDER_FIRST, audit_init, NULL); 354 355 /* 356 * Drain the audit queue and close the log at shutdown. Note that this can 357 * be called both from the system shutdown path and also from audit 358 * configuration syscalls, so 'arg' and 'howto' are ignored. 359 * 360 * XXXRW: In FreeBSD 7.x and 8.x, this fails to wait for the record queue to 361 * drain before returning, which could lead to lost records on shutdown. 362 */ 363 void 364 audit_shutdown(void *arg, int howto) 365 { 366 367 audit_rotate_vnode(NULL, NULL); 368 } 369 370 /* 371 * Return the current thread's audit record, if any. 372 */ 373 struct kaudit_record * 374 currecord(void) 375 { 376 377 return (curthread->td_ar); 378 } 379 380 /* 381 * XXXAUDIT: There are a number of races present in the code below due to 382 * release and re-grab of the mutex. The code should be revised to become 383 * slightly less racy. 384 * 385 * XXXAUDIT: Shouldn't there be logic here to sleep waiting on available 386 * pre_q space, suspending the system call until there is room? 387 */ 388 struct kaudit_record * 389 audit_new(int event, struct thread *td) 390 { 391 struct kaudit_record *ar; 392 int no_record; 393 394 mtx_lock(&audit_mtx); 395 no_record = (audit_suspended || !audit_enabled); 396 mtx_unlock(&audit_mtx); 397 if (no_record) 398 return (NULL); 399 400 /* 401 * Note: the number of outstanding uncommitted audit records is 402 * limited to the number of concurrent threads servicing system calls 403 * in the kernel. 404 */ 405 ar = uma_zalloc_arg(audit_record_zone, td, M_WAITOK); 406 ar->k_ar.ar_event = event; 407 408 mtx_lock(&audit_mtx); 409 audit_pre_q_len++; 410 mtx_unlock(&audit_mtx); 411 412 return (ar); 413 } 414 415 void 416 audit_free(struct kaudit_record *ar) 417 { 418 419 uma_zfree(audit_record_zone, ar); 420 } 421 422 void 423 audit_commit(struct kaudit_record *ar, int error, int retval) 424 { 425 au_event_t event; 426 au_class_t class; 427 au_id_t auid; 428 int sorf; 429 struct au_mask *aumask; 430 431 if (ar == NULL) 432 return; 433 434 ar->k_ar.ar_errno = error; 435 ar->k_ar.ar_retval = retval; 436 nanotime(&ar->k_ar.ar_endtime); 437 438 /* 439 * Decide whether to commit the audit record by checking the error 440 * value from the system call and using the appropriate audit mask. 441 */ 442 if (ar->k_ar.ar_subj_auid == AU_DEFAUDITID) 443 aumask = &audit_nae_mask; 444 else 445 aumask = &ar->k_ar.ar_subj_amask; 446 447 if (error) 448 sorf = AU_PRS_FAILURE; 449 else 450 sorf = AU_PRS_SUCCESS; 451 452 /* 453 * syscalls.master sometimes contains a prototype event number, which 454 * we will transform into a more specific event number now that we 455 * have more complete information gathered during the system call. 456 */ 457 switch(ar->k_ar.ar_event) { 458 case AUE_OPEN_RWTC: 459 ar->k_ar.ar_event = audit_flags_and_error_to_openevent( 460 ar->k_ar.ar_arg_fflags, error); 461 break; 462 463 case AUE_OPENAT_RWTC: 464 ar->k_ar.ar_event = audit_flags_and_error_to_openatevent( 465 ar->k_ar.ar_arg_fflags, error); 466 break; 467 468 case AUE_SYSCTL: 469 ar->k_ar.ar_event = audit_ctlname_to_sysctlevent( 470 ar->k_ar.ar_arg_ctlname, ar->k_ar.ar_valid_arg); 471 break; 472 473 case AUE_AUDITON: 474 /* Convert the auditon() command to an event. */ 475 ar->k_ar.ar_event = auditon_command_event(ar->k_ar.ar_arg_cmd); 476 break; 477 478 case AUE_MSGSYS: 479 if (ARG_IS_VALID(ar, ARG_SVIPC_WHICH)) 480 ar->k_ar.ar_event = 481 audit_msgsys_to_event(ar->k_ar.ar_arg_svipc_which); 482 break; 483 484 case AUE_SEMSYS: 485 if (ARG_IS_VALID(ar, ARG_SVIPC_WHICH)) 486 ar->k_ar.ar_event = 487 audit_semsys_to_event(ar->k_ar.ar_arg_svipc_which); 488 break; 489 490 case AUE_SHMSYS: 491 if (ARG_IS_VALID(ar, ARG_SVIPC_WHICH)) 492 ar->k_ar.ar_event = 493 audit_shmsys_to_event(ar->k_ar.ar_arg_svipc_which); 494 break; 495 } 496 497 auid = ar->k_ar.ar_subj_auid; 498 event = ar->k_ar.ar_event; 499 class = au_event_class(event); 500 501 ar->k_ar_commit |= AR_COMMIT_KERNEL; 502 if (au_preselect(event, class, aumask, sorf) != 0) 503 ar->k_ar_commit |= AR_PRESELECT_TRAIL; 504 if (audit_pipe_preselect(auid, event, class, sorf, 505 ar->k_ar_commit & AR_PRESELECT_TRAIL) != 0) 506 ar->k_ar_commit |= AR_PRESELECT_PIPE; 507 #ifdef KDTRACE_HOOKS 508 /* 509 * Expose the audit record to DTrace, both to allow the "commit" probe 510 * to fire if it's desirable, and also to allow a decision to be made 511 * about later firing with BSM in the audit worker. 512 */ 513 if (dtaudit_hook_commit != NULL) { 514 if (dtaudit_hook_commit(ar, auid, event, class, sorf) != 0) 515 ar->k_ar_commit |= AR_PRESELECT_DTRACE; 516 } 517 #endif 518 519 if ((ar->k_ar_commit & (AR_PRESELECT_TRAIL | AR_PRESELECT_PIPE | 520 AR_PRESELECT_USER_TRAIL | AR_PRESELECT_USER_PIPE | 521 AR_PRESELECT_DTRACE)) == 0) { 522 mtx_lock(&audit_mtx); 523 audit_pre_q_len--; 524 mtx_unlock(&audit_mtx); 525 audit_free(ar); 526 return; 527 } 528 529 /* 530 * Note: it could be that some records initiated while audit was 531 * enabled should still be committed? 532 */ 533 mtx_lock(&audit_mtx); 534 if (audit_suspended || !audit_enabled) { 535 audit_pre_q_len--; 536 mtx_unlock(&audit_mtx); 537 audit_free(ar); 538 return; 539 } 540 541 /* 542 * Constrain the number of committed audit records based on the 543 * configurable parameter. 544 */ 545 while (audit_q_len >= audit_qctrl.aq_hiwater) 546 cv_wait(&audit_watermark_cv, &audit_mtx); 547 548 TAILQ_INSERT_TAIL(&audit_q, ar, k_q); 549 audit_q_len++; 550 audit_pre_q_len--; 551 cv_signal(&audit_worker_cv); 552 mtx_unlock(&audit_mtx); 553 } 554 555 /* 556 * audit_syscall_enter() is called on entry to each system call. It is 557 * responsible for deciding whether or not to audit the call (preselection), 558 * and if so, allocating a per-thread audit record. audit_new() will fill in 559 * basic thread/credential properties. 560 */ 561 void 562 audit_syscall_enter(unsigned short code, struct thread *td) 563 { 564 struct au_mask *aumask; 565 #ifdef KDTRACE_HOOKS 566 void *dtaudit_state; 567 #endif 568 au_class_t class; 569 au_event_t event; 570 au_id_t auid; 571 int record_needed; 572 573 KASSERT(td->td_ar == NULL, ("audit_syscall_enter: td->td_ar != NULL")); 574 KASSERT((td->td_pflags & TDP_AUDITREC) == 0, 575 ("audit_syscall_enter: TDP_AUDITREC set")); 576 577 /* 578 * In FreeBSD, each ABI has its own system call table, and hence 579 * mapping of system call codes to audit events. Convert the code to 580 * an audit event identifier using the process system call table 581 * reference. In Darwin, there's only one, so we use the global 582 * symbol for the system call table. No audit record is generated 583 * for bad system calls, as no operation has been performed. 584 */ 585 if (code >= td->td_proc->p_sysent->sv_size) 586 return; 587 588 event = td->td_proc->p_sysent->sv_table[code].sy_auevent; 589 if (event == AUE_NULL) 590 return; 591 592 /* 593 * Check which audit mask to use; either the kernel non-attributable 594 * event mask or the process audit mask. 595 */ 596 auid = td->td_ucred->cr_audit.ai_auid; 597 if (auid == AU_DEFAUDITID) 598 aumask = &audit_nae_mask; 599 else 600 aumask = &td->td_ucred->cr_audit.ai_mask; 601 602 /* 603 * Determine whether trail or pipe preselection would like an audit 604 * record allocated for this system call. 605 */ 606 class = au_event_class(event); 607 if (au_preselect(event, class, aumask, AU_PRS_BOTH)) { 608 /* 609 * If we're out of space and need to suspend unprivileged 610 * processes, do that here rather than trying to allocate 611 * another audit record. 612 * 613 * Note: we might wish to be able to continue here in the 614 * future, if the system recovers. That should be possible 615 * by means of checking the condition in a loop around 616 * cv_wait(). It might be desirable to reevaluate whether an 617 * audit record is still required for this event by 618 * re-calling au_preselect(). 619 */ 620 if (audit_in_failure && 621 priv_check(td, PRIV_AUDIT_FAILSTOP) != 0) { 622 cv_wait(&audit_fail_cv, &audit_mtx); 623 panic("audit_failing_stop: thread continued"); 624 } 625 record_needed = 1; 626 } else if (audit_pipe_preselect(auid, event, class, AU_PRS_BOTH, 0)) { 627 record_needed = 1; 628 } else { 629 record_needed = 0; 630 } 631 632 /* 633 * After audit trails and pipes have made their policy choices, DTrace 634 * may request that records be generated as well. This is a slightly 635 * complex affair, as the DTrace audit provider needs the audit 636 * framework to maintain some state on the audit record, which has not 637 * been allocated at the point where the decision has to be made. 638 * This hook must run even if we are not changing the decision, as 639 * DTrace may want to stick event state onto a record we were going to 640 * produce due to the trail or pipes. The event state returned by the 641 * DTrace provider must be safe without locks held between here and 642 * below -- i.e., dtaudit_state must must refer to stable memory. 643 */ 644 #ifdef KDTRACE_HOOKS 645 dtaudit_state = NULL; 646 if (dtaudit_hook_preselect != NULL) { 647 dtaudit_state = dtaudit_hook_preselect(auid, event, class); 648 if (dtaudit_state != NULL) 649 record_needed = 1; 650 } 651 #endif 652 653 /* 654 * If a record is required, allocate it and attach it to the thread 655 * for use throughout the system call. Also attach DTrace state if 656 * required. 657 * 658 * XXXRW: If we decide to reference count the evname_elem underlying 659 * dtaudit_state, we will need to free here if no record is allocated 660 * or allocatable. 661 */ 662 if (record_needed) { 663 td->td_ar = audit_new(event, td); 664 if (td->td_ar != NULL) { 665 td->td_pflags |= TDP_AUDITREC; 666 #ifdef KDTRACE_HOOKS 667 td->td_ar->k_dtaudit_state = dtaudit_state; 668 #endif 669 } 670 } else 671 td->td_ar = NULL; 672 } 673 674 /* 675 * audit_syscall_exit() is called from the return of every system call, or in 676 * the event of exit1(), during the execution of exit1(). It is responsible 677 * for committing the audit record, if any, along with return condition. 678 */ 679 void 680 audit_syscall_exit(int error, struct thread *td) 681 { 682 int retval; 683 684 /* 685 * Commit the audit record as desired; once we pass the record into 686 * audit_commit(), the memory is owned by the audit subsystem. The 687 * return value from the system call is stored on the user thread. 688 * If there was an error, the return value is set to -1, imitating 689 * the behavior of the cerror routine. 690 */ 691 if (error) 692 retval = -1; 693 else 694 retval = td->td_retval[0]; 695 696 audit_commit(td->td_ar, error, retval); 697 td->td_ar = NULL; 698 td->td_pflags &= ~TDP_AUDITREC; 699 } 700 701 void 702 audit_cred_copy(struct ucred *src, struct ucred *dest) 703 { 704 705 bcopy(&src->cr_audit, &dest->cr_audit, sizeof(dest->cr_audit)); 706 } 707 708 void 709 audit_cred_destroy(struct ucred *cred) 710 { 711 712 } 713 714 void 715 audit_cred_init(struct ucred *cred) 716 { 717 718 bzero(&cred->cr_audit, sizeof(cred->cr_audit)); 719 } 720 721 /* 722 * Initialize audit information for the first kernel process (proc 0) and for 723 * the first user process (init). 724 */ 725 void 726 audit_cred_kproc0(struct ucred *cred) 727 { 728 729 cred->cr_audit.ai_auid = AU_DEFAUDITID; 730 cred->cr_audit.ai_termid.at_type = AU_IPv4; 731 } 732 733 void 734 audit_cred_proc1(struct ucred *cred) 735 { 736 737 cred->cr_audit.ai_auid = AU_DEFAUDITID; 738 cred->cr_audit.ai_termid.at_type = AU_IPv4; 739 } 740 741 void 742 audit_thread_alloc(struct thread *td) 743 { 744 745 td->td_ar = NULL; 746 } 747 748 void 749 audit_thread_free(struct thread *td) 750 { 751 752 KASSERT(td->td_ar == NULL, ("audit_thread_free: td_ar != NULL")); 753 KASSERT((td->td_pflags & TDP_AUDITREC) == 0, 754 ("audit_thread_free: TDP_AUDITREC set")); 755 } 756 757 void 758 audit_proc_coredump(struct thread *td, char *path, int errcode) 759 { 760 struct kaudit_record *ar; 761 struct au_mask *aumask; 762 struct ucred *cred; 763 au_class_t class; 764 int ret, sorf; 765 char **pathp; 766 au_id_t auid; 767 768 ret = 0; 769 770 /* 771 * Make sure we are using the correct preselection mask. 772 */ 773 cred = td->td_ucred; 774 auid = cred->cr_audit.ai_auid; 775 if (auid == AU_DEFAUDITID) 776 aumask = &audit_nae_mask; 777 else 778 aumask = &cred->cr_audit.ai_mask; 779 /* 780 * It's possible for coredump(9) generation to fail. Make sure that 781 * we handle this case correctly for preselection. 782 */ 783 if (errcode != 0) 784 sorf = AU_PRS_FAILURE; 785 else 786 sorf = AU_PRS_SUCCESS; 787 class = au_event_class(AUE_CORE); 788 if (au_preselect(AUE_CORE, class, aumask, sorf) == 0 && 789 audit_pipe_preselect(auid, AUE_CORE, class, sorf, 0) == 0) 790 return; 791 792 /* 793 * If we are interested in seeing this audit record, allocate it. 794 * Where possible coredump records should contain a pathname and arg32 795 * (signal) tokens. 796 */ 797 ar = audit_new(AUE_CORE, td); 798 if (ar == NULL) 799 return; 800 if (path != NULL) { 801 pathp = &ar->k_ar.ar_arg_upath1; 802 *pathp = malloc(MAXPATHLEN, M_AUDITPATH, M_WAITOK); 803 audit_canon_path(td, AT_FDCWD, path, *pathp); 804 ARG_SET_VALID(ar, ARG_UPATH1); 805 } 806 ar->k_ar.ar_arg_signum = td->td_proc->p_sig; 807 ARG_SET_VALID(ar, ARG_SIGNUM); 808 if (errcode != 0) 809 ret = 1; 810 audit_commit(ar, errcode, ret); 811 } 812