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 i++; 225 } 226 sx_sunlock(&proctree_lock); 227 error = copyout(pi, rp->rp_pids, i * sizeof(*pi)); 228 free(pi, M_TEMP); 229 sx_slock(&proctree_lock); 230 PROC_LOCK(p); 231 return (error); 232 } 233 234 static int 235 reap_kill(struct thread *td, struct proc *p, struct procctl_reaper_kill *rk) 236 { 237 struct proc *reap, *p2; 238 ksiginfo_t ksi; 239 int error, error1; 240 241 sx_assert(&proctree_lock, SX_LOCKED); 242 if (IN_CAPABILITY_MODE(td)) 243 return (ECAPMODE); 244 if (rk->rk_sig <= 0 || rk->rk_sig > _SIG_MAXSIG) 245 return (EINVAL); 246 if ((rk->rk_flags & ~REAPER_KILL_CHILDREN) != 0) 247 return (EINVAL); 248 PROC_UNLOCK(p); 249 reap = (p->p_treeflag & P_TREE_REAPER) == 0 ? p->p_reaper : p; 250 ksiginfo_init(&ksi); 251 ksi.ksi_signo = rk->rk_sig; 252 ksi.ksi_code = SI_USER; 253 ksi.ksi_pid = td->td_proc->p_pid; 254 ksi.ksi_uid = td->td_ucred->cr_ruid; 255 error = ESRCH; 256 rk->rk_killed = 0; 257 rk->rk_fpid = -1; 258 for (p2 = (rk->rk_flags & REAPER_KILL_CHILDREN) != 0 ? 259 LIST_FIRST(&reap->p_children) : LIST_FIRST(&reap->p_reaplist); 260 p2 != NULL; 261 p2 = (rk->rk_flags & REAPER_KILL_CHILDREN) != 0 ? 262 LIST_NEXT(p2, p_sibling) : LIST_NEXT(p2, p_reapsibling)) { 263 if ((rk->rk_flags & REAPER_KILL_SUBTREE) != 0 && 264 p2->p_reapsubtree != rk->rk_subtree) 265 continue; 266 PROC_LOCK(p2); 267 error1 = p_cansignal(td, p2, rk->rk_sig); 268 if (error1 == 0) { 269 pksignal(p2, rk->rk_sig, &ksi); 270 rk->rk_killed++; 271 error = error1; 272 } else if (error == ESRCH) { 273 error = error1; 274 rk->rk_fpid = p2->p_pid; 275 } 276 PROC_UNLOCK(p2); 277 /* Do not end the loop on error, signal everything we can. */ 278 } 279 PROC_LOCK(p); 280 return (error); 281 } 282 283 static int 284 trace_ctl(struct thread *td, struct proc *p, int state) 285 { 286 287 PROC_LOCK_ASSERT(p, MA_OWNED); 288 289 /* 290 * Ktrace changes p_traceflag from or to zero under the 291 * process lock, so the test does not need to acquire ktrace 292 * mutex. 293 */ 294 if ((p->p_flag & P_TRACED) != 0 || p->p_traceflag != 0) 295 return (EBUSY); 296 297 switch (state) { 298 case PROC_TRACE_CTL_ENABLE: 299 if (td->td_proc != p) 300 return (EPERM); 301 p->p_flag2 &= ~(P2_NOTRACE | P2_NOTRACE_EXEC); 302 break; 303 case PROC_TRACE_CTL_DISABLE_EXEC: 304 p->p_flag2 |= P2_NOTRACE_EXEC | P2_NOTRACE; 305 break; 306 case PROC_TRACE_CTL_DISABLE: 307 if ((p->p_flag2 & P2_NOTRACE_EXEC) != 0) { 308 KASSERT((p->p_flag2 & P2_NOTRACE) != 0, 309 ("dandling P2_NOTRACE_EXEC")); 310 if (td->td_proc != p) 311 return (EPERM); 312 p->p_flag2 &= ~P2_NOTRACE_EXEC; 313 } else { 314 p->p_flag2 |= P2_NOTRACE; 315 } 316 break; 317 default: 318 return (EINVAL); 319 } 320 return (0); 321 } 322 323 static int 324 trace_status(struct thread *td, struct proc *p, int *data) 325 { 326 327 if ((p->p_flag2 & P2_NOTRACE) != 0) { 328 KASSERT((p->p_flag & P_TRACED) == 0, 329 ("%d traced but tracing disabled", p->p_pid)); 330 *data = -1; 331 } else if ((p->p_flag & P_TRACED) != 0) { 332 *data = p->p_pptr->p_pid; 333 } else { 334 *data = 0; 335 } 336 return (0); 337 } 338 339 static int 340 trapcap_ctl(struct thread *td, struct proc *p, int state) 341 { 342 343 PROC_LOCK_ASSERT(p, MA_OWNED); 344 345 switch (state) { 346 case PROC_TRAPCAP_CTL_ENABLE: 347 p->p_flag2 |= P2_TRAPCAP; 348 break; 349 case PROC_TRAPCAP_CTL_DISABLE: 350 p->p_flag2 &= ~P2_TRAPCAP; 351 break; 352 default: 353 return (EINVAL); 354 } 355 return (0); 356 } 357 358 static int 359 trapcap_status(struct thread *td, struct proc *p, int *data) 360 { 361 362 *data = (p->p_flag2 & P2_TRAPCAP) != 0 ? PROC_TRAPCAP_CTL_ENABLE : 363 PROC_TRAPCAP_CTL_DISABLE; 364 return (0); 365 } 366 367 #ifndef _SYS_SYSPROTO_H_ 368 struct procctl_args { 369 idtype_t idtype; 370 id_t id; 371 int com; 372 void *data; 373 }; 374 #endif 375 /* ARGSUSED */ 376 int 377 sys_procctl(struct thread *td, struct procctl_args *uap) 378 { 379 void *data; 380 union { 381 struct procctl_reaper_status rs; 382 struct procctl_reaper_pids rp; 383 struct procctl_reaper_kill rk; 384 } x; 385 int error, error1, flags; 386 387 switch (uap->com) { 388 case PROC_SPROTECT: 389 case PROC_TRACE_CTL: 390 case PROC_TRAPCAP_CTL: 391 error = copyin(uap->data, &flags, sizeof(flags)); 392 if (error != 0) 393 return (error); 394 data = &flags; 395 break; 396 case PROC_REAP_ACQUIRE: 397 case PROC_REAP_RELEASE: 398 if (uap->data != NULL) 399 return (EINVAL); 400 data = NULL; 401 break; 402 case PROC_REAP_STATUS: 403 data = &x.rs; 404 break; 405 case PROC_REAP_GETPIDS: 406 error = copyin(uap->data, &x.rp, sizeof(x.rp)); 407 if (error != 0) 408 return (error); 409 data = &x.rp; 410 break; 411 case PROC_REAP_KILL: 412 error = copyin(uap->data, &x.rk, sizeof(x.rk)); 413 if (error != 0) 414 return (error); 415 data = &x.rk; 416 break; 417 case PROC_TRACE_STATUS: 418 case PROC_TRAPCAP_STATUS: 419 data = &flags; 420 break; 421 default: 422 return (EINVAL); 423 } 424 error = kern_procctl(td, uap->idtype, uap->id, uap->com, data); 425 switch (uap->com) { 426 case PROC_REAP_STATUS: 427 if (error == 0) 428 error = copyout(&x.rs, uap->data, sizeof(x.rs)); 429 break; 430 case PROC_REAP_KILL: 431 error1 = copyout(&x.rk, uap->data, sizeof(x.rk)); 432 if (error == 0) 433 error = error1; 434 break; 435 case PROC_TRACE_STATUS: 436 case PROC_TRAPCAP_STATUS: 437 if (error == 0) 438 error = copyout(&flags, uap->data, sizeof(flags)); 439 break; 440 } 441 return (error); 442 } 443 444 static int 445 kern_procctl_single(struct thread *td, struct proc *p, int com, void *data) 446 { 447 448 PROC_LOCK_ASSERT(p, MA_OWNED); 449 switch (com) { 450 case PROC_SPROTECT: 451 return (protect_set(td, p, *(int *)data)); 452 case PROC_REAP_ACQUIRE: 453 return (reap_acquire(td, p)); 454 case PROC_REAP_RELEASE: 455 return (reap_release(td, p)); 456 case PROC_REAP_STATUS: 457 return (reap_status(td, p, data)); 458 case PROC_REAP_GETPIDS: 459 return (reap_getpids(td, p, data)); 460 case PROC_REAP_KILL: 461 return (reap_kill(td, p, data)); 462 case PROC_TRACE_CTL: 463 return (trace_ctl(td, p, *(int *)data)); 464 case PROC_TRACE_STATUS: 465 return (trace_status(td, p, data)); 466 case PROC_TRAPCAP_CTL: 467 return (trapcap_ctl(td, p, *(int *)data)); 468 case PROC_TRAPCAP_STATUS: 469 return (trapcap_status(td, p, data)); 470 default: 471 return (EINVAL); 472 } 473 } 474 475 int 476 kern_procctl(struct thread *td, idtype_t idtype, id_t id, int com, void *data) 477 { 478 struct pgrp *pg; 479 struct proc *p; 480 int error, first_error, ok; 481 bool tree_locked; 482 483 switch (com) { 484 case PROC_REAP_ACQUIRE: 485 case PROC_REAP_RELEASE: 486 case PROC_REAP_STATUS: 487 case PROC_REAP_GETPIDS: 488 case PROC_REAP_KILL: 489 case PROC_TRACE_STATUS: 490 case PROC_TRAPCAP_STATUS: 491 if (idtype != P_PID) 492 return (EINVAL); 493 } 494 495 switch (com) { 496 case PROC_SPROTECT: 497 case PROC_REAP_STATUS: 498 case PROC_REAP_GETPIDS: 499 case PROC_REAP_KILL: 500 case PROC_TRACE_CTL: 501 case PROC_TRAPCAP_CTL: 502 sx_slock(&proctree_lock); 503 tree_locked = true; 504 break; 505 case PROC_REAP_ACQUIRE: 506 case PROC_REAP_RELEASE: 507 sx_xlock(&proctree_lock); 508 tree_locked = true; 509 break; 510 case PROC_TRACE_STATUS: 511 case PROC_TRAPCAP_STATUS: 512 tree_locked = false; 513 break; 514 default: 515 return (EINVAL); 516 } 517 518 switch (idtype) { 519 case P_PID: 520 p = pfind(id); 521 if (p == NULL) { 522 error = ESRCH; 523 break; 524 } 525 error = p_cansee(td, p); 526 if (error == 0) 527 error = kern_procctl_single(td, p, com, data); 528 PROC_UNLOCK(p); 529 break; 530 case P_PGID: 531 /* 532 * Attempt to apply the operation to all members of the 533 * group. Ignore processes in the group that can't be 534 * seen. Ignore errors so long as at least one process is 535 * able to complete the request successfully. 536 */ 537 pg = pgfind(id); 538 if (pg == NULL) { 539 error = ESRCH; 540 break; 541 } 542 PGRP_UNLOCK(pg); 543 ok = 0; 544 first_error = 0; 545 LIST_FOREACH(p, &pg->pg_members, p_pglist) { 546 PROC_LOCK(p); 547 if (p->p_state == PRS_NEW || p_cansee(td, p) != 0) { 548 PROC_UNLOCK(p); 549 continue; 550 } 551 error = kern_procctl_single(td, p, com, data); 552 PROC_UNLOCK(p); 553 if (error == 0) 554 ok = 1; 555 else if (first_error == 0) 556 first_error = error; 557 } 558 if (ok) 559 error = 0; 560 else if (first_error != 0) 561 error = first_error; 562 else 563 /* 564 * Was not able to see any processes in the 565 * process group. 566 */ 567 error = ESRCH; 568 break; 569 default: 570 error = EINVAL; 571 break; 572 } 573 if (tree_locked) 574 sx_unlock(&proctree_lock); 575 return (error); 576 } 577