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