1 /*- 2 * Copyright (c) 2014 John Baldwin 3 * Copyright (c) 2014, 2016 The FreeBSD Foundation 4 * 5 * Portions of this software were developed by Konstantin Belousov 6 * under sponsorship from the FreeBSD Foundation. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/capsicum.h> 36 #include <sys/lock.h> 37 #include <sys/mutex.h> 38 #include <sys/priv.h> 39 #include <sys/proc.h> 40 #include <sys/procctl.h> 41 #include <sys/sx.h> 42 #include <sys/syscallsubr.h> 43 #include <sys/sysproto.h> 44 #include <sys/wait.h> 45 46 static int 47 protect_setchild(struct thread *td, struct proc *p, int flags) 48 { 49 50 PROC_LOCK_ASSERT(p, MA_OWNED); 51 if (p->p_flag & P_SYSTEM || p_cansched(td, p) != 0) 52 return (0); 53 if (flags & PPROT_SET) { 54 p->p_flag |= P_PROTECTED; 55 if (flags & PPROT_INHERIT) 56 p->p_flag2 |= P2_INHERIT_PROTECTED; 57 } else { 58 p->p_flag &= ~P_PROTECTED; 59 p->p_flag2 &= ~P2_INHERIT_PROTECTED; 60 } 61 return (1); 62 } 63 64 static int 65 protect_setchildren(struct thread *td, struct proc *top, int flags) 66 { 67 struct proc *p; 68 int ret; 69 70 p = top; 71 ret = 0; 72 sx_assert(&proctree_lock, SX_LOCKED); 73 for (;;) { 74 ret |= protect_setchild(td, p, flags); 75 PROC_UNLOCK(p); 76 /* 77 * If this process has children, descend to them next, 78 * otherwise do any siblings, and if done with this level, 79 * follow back up the tree (but not past top). 80 */ 81 if (!LIST_EMPTY(&p->p_children)) 82 p = LIST_FIRST(&p->p_children); 83 else for (;;) { 84 if (p == top) { 85 PROC_LOCK(p); 86 return (ret); 87 } 88 if (LIST_NEXT(p, p_sibling)) { 89 p = LIST_NEXT(p, p_sibling); 90 break; 91 } 92 p = p->p_pptr; 93 } 94 PROC_LOCK(p); 95 } 96 } 97 98 static int 99 protect_set(struct thread *td, struct proc *p, int flags) 100 { 101 int error, ret; 102 103 switch (PPROT_OP(flags)) { 104 case PPROT_SET: 105 case PPROT_CLEAR: 106 break; 107 default: 108 return (EINVAL); 109 } 110 111 if ((PPROT_FLAGS(flags) & ~(PPROT_DESCEND | PPROT_INHERIT)) != 0) 112 return (EINVAL); 113 114 error = priv_check(td, PRIV_VM_MADV_PROTECT); 115 if (error) 116 return (error); 117 118 if (flags & PPROT_DESCEND) 119 ret = protect_setchildren(td, p, flags); 120 else 121 ret = protect_setchild(td, p, flags); 122 if (ret == 0) 123 return (EPERM); 124 return (0); 125 } 126 127 static int 128 reap_acquire(struct thread *td, struct proc *p) 129 { 130 131 sx_assert(&proctree_lock, SX_XLOCKED); 132 if (p != curproc) 133 return (EPERM); 134 if ((p->p_treeflag & P_TREE_REAPER) != 0) 135 return (EBUSY); 136 p->p_treeflag |= P_TREE_REAPER; 137 /* 138 * We do not reattach existing children and the whole tree 139 * under them to us, since p->p_reaper already seen them. 140 */ 141 return (0); 142 } 143 144 static int 145 reap_release(struct thread *td, struct proc *p) 146 { 147 148 sx_assert(&proctree_lock, SX_XLOCKED); 149 if (p != curproc) 150 return (EPERM); 151 if (p == initproc) 152 return (EINVAL); 153 if ((p->p_treeflag & P_TREE_REAPER) == 0) 154 return (EINVAL); 155 reaper_abandon_children(p, false); 156 return (0); 157 } 158 159 static int 160 reap_status(struct thread *td, struct proc *p, 161 struct procctl_reaper_status *rs) 162 { 163 struct proc *reap, *p2, *first_p; 164 165 sx_assert(&proctree_lock, SX_LOCKED); 166 bzero(rs, sizeof(*rs)); 167 if ((p->p_treeflag & P_TREE_REAPER) == 0) { 168 reap = p->p_reaper; 169 } else { 170 reap = p; 171 rs->rs_flags |= REAPER_STATUS_OWNED; 172 } 173 if (reap == initproc) 174 rs->rs_flags |= REAPER_STATUS_REALINIT; 175 rs->rs_reaper = reap->p_pid; 176 rs->rs_descendants = 0; 177 rs->rs_children = 0; 178 if (!LIST_EMPTY(&reap->p_reaplist)) { 179 first_p = LIST_FIRST(&reap->p_children); 180 if (first_p == NULL) 181 first_p = LIST_FIRST(&reap->p_reaplist); 182 rs->rs_pid = first_p->p_pid; 183 LIST_FOREACH(p2, &reap->p_reaplist, p_reapsibling) { 184 if (proc_realparent(p2) == reap) 185 rs->rs_children++; 186 rs->rs_descendants++; 187 } 188 } else { 189 rs->rs_pid = -1; 190 } 191 return (0); 192 } 193 194 static int 195 reap_getpids(struct thread *td, struct proc *p, struct procctl_reaper_pids *rp) 196 { 197 struct proc *reap, *p2; 198 struct procctl_reaper_pidinfo *pi, *pip; 199 u_int i, n; 200 int error; 201 202 sx_assert(&proctree_lock, SX_LOCKED); 203 PROC_UNLOCK(p); 204 reap = (p->p_treeflag & P_TREE_REAPER) == 0 ? p->p_reaper : p; 205 n = i = 0; 206 error = 0; 207 LIST_FOREACH(p2, &reap->p_reaplist, p_reapsibling) 208 n++; 209 sx_unlock(&proctree_lock); 210 if (rp->rp_count < n) 211 n = rp->rp_count; 212 pi = malloc(n * sizeof(*pi), M_TEMP, M_WAITOK); 213 sx_slock(&proctree_lock); 214 LIST_FOREACH(p2, &reap->p_reaplist, p_reapsibling) { 215 if (i == n) 216 break; 217 pip = &pi[i]; 218 bzero(pip, sizeof(*pip)); 219 pip->pi_pid = p2->p_pid; 220 pip->pi_subtree = p2->p_reapsubtree; 221 pip->pi_flags = REAPER_PIDINFO_VALID; 222 if (proc_realparent(p2) == reap) 223 pip->pi_flags |= REAPER_PIDINFO_CHILD; 224 if ((p2->p_treeflag & P_TREE_REAPER) != 0) 225 pip->pi_flags |= REAPER_PIDINFO_REAPER; 226 i++; 227 } 228 sx_sunlock(&proctree_lock); 229 error = copyout(pi, rp->rp_pids, i * sizeof(*pi)); 230 free(pi, M_TEMP); 231 sx_slock(&proctree_lock); 232 PROC_LOCK(p); 233 return (error); 234 } 235 236 static void 237 reap_kill_proc(struct thread *td, struct proc *p2, ksiginfo_t *ksi, 238 struct procctl_reaper_kill *rk, int *error) 239 { 240 int error1; 241 242 PROC_LOCK(p2); 243 error1 = p_cansignal(td, p2, rk->rk_sig); 244 if (error1 == 0) { 245 pksignal(p2, rk->rk_sig, ksi); 246 rk->rk_killed++; 247 *error = error1; 248 } else if (*error == ESRCH) { 249 rk->rk_fpid = p2->p_pid; 250 *error = error1; 251 } 252 PROC_UNLOCK(p2); 253 } 254 255 struct reap_kill_tracker { 256 struct proc *parent; 257 TAILQ_ENTRY(reap_kill_tracker) link; 258 }; 259 260 TAILQ_HEAD(reap_kill_tracker_head, reap_kill_tracker); 261 262 static void 263 reap_kill_sched(struct reap_kill_tracker_head *tracker, struct proc *p2) 264 { 265 struct reap_kill_tracker *t; 266 267 t = malloc(sizeof(struct reap_kill_tracker), M_TEMP, M_WAITOK); 268 t->parent = p2; 269 TAILQ_INSERT_TAIL(tracker, t, link); 270 } 271 272 static int 273 reap_kill(struct thread *td, struct proc *p, struct procctl_reaper_kill *rk) 274 { 275 struct proc *reap, *p2; 276 ksiginfo_t ksi; 277 struct reap_kill_tracker_head tracker; 278 struct reap_kill_tracker *t; 279 int error; 280 281 sx_assert(&proctree_lock, SX_LOCKED); 282 if (IN_CAPABILITY_MODE(td)) 283 return (ECAPMODE); 284 if (rk->rk_sig <= 0 || rk->rk_sig > _SIG_MAXSIG || 285 (rk->rk_flags & ~(REAPER_KILL_CHILDREN | 286 REAPER_KILL_SUBTREE)) != 0 || (rk->rk_flags & 287 (REAPER_KILL_CHILDREN | REAPER_KILL_SUBTREE)) == 288 (REAPER_KILL_CHILDREN | REAPER_KILL_SUBTREE)) 289 return (EINVAL); 290 PROC_UNLOCK(p); 291 reap = (p->p_treeflag & P_TREE_REAPER) == 0 ? p->p_reaper : p; 292 ksiginfo_init(&ksi); 293 ksi.ksi_signo = rk->rk_sig; 294 ksi.ksi_code = SI_USER; 295 ksi.ksi_pid = td->td_proc->p_pid; 296 ksi.ksi_uid = td->td_ucred->cr_ruid; 297 error = ESRCH; 298 rk->rk_killed = 0; 299 rk->rk_fpid = -1; 300 if ((rk->rk_flags & REAPER_KILL_CHILDREN) != 0) { 301 for (p2 = LIST_FIRST(&reap->p_children); p2 != NULL; 302 p2 = LIST_NEXT(p2, p_sibling)) { 303 reap_kill_proc(td, p2, &ksi, rk, &error); 304 /* 305 * Do not end the loop on error, signal 306 * everything we can. 307 */ 308 } 309 } else { 310 TAILQ_INIT(&tracker); 311 reap_kill_sched(&tracker, reap); 312 while ((t = TAILQ_FIRST(&tracker)) != NULL) { 313 MPASS((t->parent->p_treeflag & P_TREE_REAPER) != 0); 314 TAILQ_REMOVE(&tracker, t, link); 315 for (p2 = LIST_FIRST(&t->parent->p_reaplist); p2 != NULL; 316 p2 = LIST_NEXT(p2, p_reapsibling)) { 317 if (t->parent == reap && 318 (rk->rk_flags & REAPER_KILL_SUBTREE) != 0 && 319 p2->p_reapsubtree != rk->rk_subtree) 320 continue; 321 if ((p2->p_treeflag & P_TREE_REAPER) != 0) 322 reap_kill_sched(&tracker, p2); 323 reap_kill_proc(td, p2, &ksi, rk, &error); 324 } 325 free(t, M_TEMP); 326 } 327 } 328 PROC_LOCK(p); 329 return (error); 330 } 331 332 static int 333 trace_ctl(struct thread *td, struct proc *p, int state) 334 { 335 336 PROC_LOCK_ASSERT(p, MA_OWNED); 337 338 /* 339 * Ktrace changes p_traceflag from or to zero under the 340 * process lock, so the test does not need to acquire ktrace 341 * mutex. 342 */ 343 if ((p->p_flag & P_TRACED) != 0 || p->p_traceflag != 0) 344 return (EBUSY); 345 346 switch (state) { 347 case PROC_TRACE_CTL_ENABLE: 348 if (td->td_proc != p) 349 return (EPERM); 350 p->p_flag2 &= ~(P2_NOTRACE | P2_NOTRACE_EXEC); 351 break; 352 case PROC_TRACE_CTL_DISABLE_EXEC: 353 p->p_flag2 |= P2_NOTRACE_EXEC | P2_NOTRACE; 354 break; 355 case PROC_TRACE_CTL_DISABLE: 356 if ((p->p_flag2 & P2_NOTRACE_EXEC) != 0) { 357 KASSERT((p->p_flag2 & P2_NOTRACE) != 0, 358 ("dandling P2_NOTRACE_EXEC")); 359 if (td->td_proc != p) 360 return (EPERM); 361 p->p_flag2 &= ~P2_NOTRACE_EXEC; 362 } else { 363 p->p_flag2 |= P2_NOTRACE; 364 } 365 break; 366 default: 367 return (EINVAL); 368 } 369 return (0); 370 } 371 372 static int 373 trace_status(struct thread *td, struct proc *p, int *data) 374 { 375 376 if ((p->p_flag2 & P2_NOTRACE) != 0) { 377 KASSERT((p->p_flag & P_TRACED) == 0, 378 ("%d traced but tracing disabled", p->p_pid)); 379 *data = -1; 380 } else if ((p->p_flag & P_TRACED) != 0) { 381 *data = p->p_pptr->p_pid; 382 } else { 383 *data = 0; 384 } 385 return (0); 386 } 387 388 static int 389 trapcap_ctl(struct thread *td, struct proc *p, int state) 390 { 391 392 PROC_LOCK_ASSERT(p, MA_OWNED); 393 394 switch (state) { 395 case PROC_TRAPCAP_CTL_ENABLE: 396 p->p_flag2 |= P2_TRAPCAP; 397 break; 398 case PROC_TRAPCAP_CTL_DISABLE: 399 p->p_flag2 &= ~P2_TRAPCAP; 400 break; 401 default: 402 return (EINVAL); 403 } 404 return (0); 405 } 406 407 static int 408 trapcap_status(struct thread *td, struct proc *p, int *data) 409 { 410 411 *data = (p->p_flag2 & P2_TRAPCAP) != 0 ? PROC_TRAPCAP_CTL_ENABLE : 412 PROC_TRAPCAP_CTL_DISABLE; 413 return (0); 414 } 415 416 #ifndef _SYS_SYSPROTO_H_ 417 struct procctl_args { 418 idtype_t idtype; 419 id_t id; 420 int com; 421 void *data; 422 }; 423 #endif 424 /* ARGSUSED */ 425 int 426 sys_procctl(struct thread *td, struct procctl_args *uap) 427 { 428 void *data; 429 union { 430 struct procctl_reaper_status rs; 431 struct procctl_reaper_pids rp; 432 struct procctl_reaper_kill rk; 433 } x; 434 int error, error1, flags; 435 436 switch (uap->com) { 437 case PROC_SPROTECT: 438 case PROC_TRACE_CTL: 439 case PROC_TRAPCAP_CTL: 440 error = copyin(uap->data, &flags, sizeof(flags)); 441 if (error != 0) 442 return (error); 443 data = &flags; 444 break; 445 case PROC_REAP_ACQUIRE: 446 case PROC_REAP_RELEASE: 447 if (uap->data != NULL) 448 return (EINVAL); 449 data = NULL; 450 break; 451 case PROC_REAP_STATUS: 452 data = &x.rs; 453 break; 454 case PROC_REAP_GETPIDS: 455 error = copyin(uap->data, &x.rp, sizeof(x.rp)); 456 if (error != 0) 457 return (error); 458 data = &x.rp; 459 break; 460 case PROC_REAP_KILL: 461 error = copyin(uap->data, &x.rk, sizeof(x.rk)); 462 if (error != 0) 463 return (error); 464 data = &x.rk; 465 break; 466 case PROC_TRACE_STATUS: 467 case PROC_TRAPCAP_STATUS: 468 data = &flags; 469 break; 470 default: 471 return (EINVAL); 472 } 473 error = kern_procctl(td, uap->idtype, uap->id, uap->com, data); 474 switch (uap->com) { 475 case PROC_REAP_STATUS: 476 if (error == 0) 477 error = copyout(&x.rs, uap->data, sizeof(x.rs)); 478 break; 479 case PROC_REAP_KILL: 480 error1 = copyout(&x.rk, uap->data, sizeof(x.rk)); 481 if (error == 0) 482 error = error1; 483 break; 484 case PROC_TRACE_STATUS: 485 case PROC_TRAPCAP_STATUS: 486 if (error == 0) 487 error = copyout(&flags, uap->data, sizeof(flags)); 488 break; 489 } 490 return (error); 491 } 492 493 static int 494 kern_procctl_single(struct thread *td, struct proc *p, int com, void *data) 495 { 496 497 PROC_LOCK_ASSERT(p, MA_OWNED); 498 switch (com) { 499 case PROC_SPROTECT: 500 return (protect_set(td, p, *(int *)data)); 501 case PROC_REAP_ACQUIRE: 502 return (reap_acquire(td, p)); 503 case PROC_REAP_RELEASE: 504 return (reap_release(td, p)); 505 case PROC_REAP_STATUS: 506 return (reap_status(td, p, data)); 507 case PROC_REAP_GETPIDS: 508 return (reap_getpids(td, p, data)); 509 case PROC_REAP_KILL: 510 return (reap_kill(td, p, data)); 511 case PROC_TRACE_CTL: 512 return (trace_ctl(td, p, *(int *)data)); 513 case PROC_TRACE_STATUS: 514 return (trace_status(td, p, data)); 515 case PROC_TRAPCAP_CTL: 516 return (trapcap_ctl(td, p, *(int *)data)); 517 case PROC_TRAPCAP_STATUS: 518 return (trapcap_status(td, p, data)); 519 default: 520 return (EINVAL); 521 } 522 } 523 524 int 525 kern_procctl(struct thread *td, idtype_t idtype, id_t id, int com, void *data) 526 { 527 struct pgrp *pg; 528 struct proc *p; 529 int error, first_error, ok; 530 bool tree_locked; 531 532 switch (com) { 533 case PROC_REAP_ACQUIRE: 534 case PROC_REAP_RELEASE: 535 case PROC_REAP_STATUS: 536 case PROC_REAP_GETPIDS: 537 case PROC_REAP_KILL: 538 case PROC_TRACE_STATUS: 539 case PROC_TRAPCAP_STATUS: 540 if (idtype != P_PID) 541 return (EINVAL); 542 } 543 544 switch (com) { 545 case PROC_SPROTECT: 546 case PROC_REAP_STATUS: 547 case PROC_REAP_GETPIDS: 548 case PROC_REAP_KILL: 549 case PROC_TRACE_CTL: 550 case PROC_TRAPCAP_CTL: 551 sx_slock(&proctree_lock); 552 tree_locked = true; 553 break; 554 case PROC_REAP_ACQUIRE: 555 case PROC_REAP_RELEASE: 556 sx_xlock(&proctree_lock); 557 tree_locked = true; 558 break; 559 case PROC_TRACE_STATUS: 560 case PROC_TRAPCAP_STATUS: 561 tree_locked = false; 562 break; 563 default: 564 return (EINVAL); 565 } 566 567 switch (idtype) { 568 case P_PID: 569 p = pfind(id); 570 if (p == NULL) { 571 error = ESRCH; 572 break; 573 } 574 error = p_cansee(td, p); 575 if (error == 0) 576 error = kern_procctl_single(td, p, com, data); 577 PROC_UNLOCK(p); 578 break; 579 case P_PGID: 580 /* 581 * Attempt to apply the operation to all members of the 582 * group. Ignore processes in the group that can't be 583 * seen. Ignore errors so long as at least one process is 584 * able to complete the request successfully. 585 */ 586 pg = pgfind(id); 587 if (pg == NULL) { 588 error = ESRCH; 589 break; 590 } 591 PGRP_UNLOCK(pg); 592 ok = 0; 593 first_error = 0; 594 LIST_FOREACH(p, &pg->pg_members, p_pglist) { 595 PROC_LOCK(p); 596 if (p->p_state == PRS_NEW || p_cansee(td, p) != 0) { 597 PROC_UNLOCK(p); 598 continue; 599 } 600 error = kern_procctl_single(td, p, com, data); 601 PROC_UNLOCK(p); 602 if (error == 0) 603 ok = 1; 604 else if (first_error == 0) 605 first_error = error; 606 } 607 if (ok) 608 error = 0; 609 else if (first_error != 0) 610 error = first_error; 611 else 612 /* 613 * Was not able to see any processes in the 614 * process group. 615 */ 616 error = ESRCH; 617 break; 618 default: 619 error = EINVAL; 620 break; 621 } 622 if (tree_locked) 623 sx_unlock(&proctree_lock); 624 return (error); 625 } 626