1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/kernel/sys.c 4 * 5 * Copyright (C) 1991, 1992 Linus Torvalds 6 */ 7 8 #include <linux/export.h> 9 #include <linux/mm.h> 10 #include <linux/utsname.h> 11 #include <linux/mman.h> 12 #include <linux/reboot.h> 13 #include <linux/prctl.h> 14 #include <linux/highuid.h> 15 #include <linux/fs.h> 16 #include <linux/kmod.h> 17 #include <linux/perf_event.h> 18 #include <linux/resource.h> 19 #include <linux/kernel.h> 20 #include <linux/workqueue.h> 21 #include <linux/capability.h> 22 #include <linux/device.h> 23 #include <linux/key.h> 24 #include <linux/times.h> 25 #include <linux/posix-timers.h> 26 #include <linux/security.h> 27 #include <linux/suspend.h> 28 #include <linux/tty.h> 29 #include <linux/signal.h> 30 #include <linux/cn_proc.h> 31 #include <linux/getcpu.h> 32 #include <linux/task_io_accounting_ops.h> 33 #include <linux/seccomp.h> 34 #include <linux/cpu.h> 35 #include <linux/personality.h> 36 #include <linux/ptrace.h> 37 #include <linux/fs_struct.h> 38 #include <linux/file.h> 39 #include <linux/mount.h> 40 #include <linux/gfp.h> 41 #include <linux/syscore_ops.h> 42 #include <linux/version.h> 43 #include <linux/ctype.h> 44 #include <linux/syscall_user_dispatch.h> 45 46 #include <linux/compat.h> 47 #include <linux/syscalls.h> 48 #include <linux/kprobes.h> 49 #include <linux/user_namespace.h> 50 #include <linux/time_namespace.h> 51 #include <linux/binfmts.h> 52 53 #include <linux/sched.h> 54 #include <linux/sched/autogroup.h> 55 #include <linux/sched/loadavg.h> 56 #include <linux/sched/stat.h> 57 #include <linux/sched/mm.h> 58 #include <linux/sched/coredump.h> 59 #include <linux/sched/task.h> 60 #include <linux/sched/cputime.h> 61 #include <linux/rcupdate.h> 62 #include <linux/uidgid.h> 63 #include <linux/cred.h> 64 65 #include <linux/nospec.h> 66 67 #include <linux/kmsg_dump.h> 68 /* Move somewhere else to avoid recompiling? */ 69 #include <generated/utsrelease.h> 70 71 #include <linux/uaccess.h> 72 #include <asm/io.h> 73 #include <asm/unistd.h> 74 75 #include "uid16.h" 76 77 #ifndef SET_UNALIGN_CTL 78 # define SET_UNALIGN_CTL(a, b) (-EINVAL) 79 #endif 80 #ifndef GET_UNALIGN_CTL 81 # define GET_UNALIGN_CTL(a, b) (-EINVAL) 82 #endif 83 #ifndef SET_FPEMU_CTL 84 # define SET_FPEMU_CTL(a, b) (-EINVAL) 85 #endif 86 #ifndef GET_FPEMU_CTL 87 # define GET_FPEMU_CTL(a, b) (-EINVAL) 88 #endif 89 #ifndef SET_FPEXC_CTL 90 # define SET_FPEXC_CTL(a, b) (-EINVAL) 91 #endif 92 #ifndef GET_FPEXC_CTL 93 # define GET_FPEXC_CTL(a, b) (-EINVAL) 94 #endif 95 #ifndef GET_ENDIAN 96 # define GET_ENDIAN(a, b) (-EINVAL) 97 #endif 98 #ifndef SET_ENDIAN 99 # define SET_ENDIAN(a, b) (-EINVAL) 100 #endif 101 #ifndef GET_TSC_CTL 102 # define GET_TSC_CTL(a) (-EINVAL) 103 #endif 104 #ifndef SET_TSC_CTL 105 # define SET_TSC_CTL(a) (-EINVAL) 106 #endif 107 #ifndef GET_FP_MODE 108 # define GET_FP_MODE(a) (-EINVAL) 109 #endif 110 #ifndef SET_FP_MODE 111 # define SET_FP_MODE(a,b) (-EINVAL) 112 #endif 113 #ifndef SVE_SET_VL 114 # define SVE_SET_VL(a) (-EINVAL) 115 #endif 116 #ifndef SVE_GET_VL 117 # define SVE_GET_VL() (-EINVAL) 118 #endif 119 #ifndef PAC_RESET_KEYS 120 # define PAC_RESET_KEYS(a, b) (-EINVAL) 121 #endif 122 #ifndef PAC_SET_ENABLED_KEYS 123 # define PAC_SET_ENABLED_KEYS(a, b, c) (-EINVAL) 124 #endif 125 #ifndef PAC_GET_ENABLED_KEYS 126 # define PAC_GET_ENABLED_KEYS(a) (-EINVAL) 127 #endif 128 #ifndef SET_TAGGED_ADDR_CTRL 129 # define SET_TAGGED_ADDR_CTRL(a) (-EINVAL) 130 #endif 131 #ifndef GET_TAGGED_ADDR_CTRL 132 # define GET_TAGGED_ADDR_CTRL() (-EINVAL) 133 #endif 134 135 /* 136 * this is where the system-wide overflow UID and GID are defined, for 137 * architectures that now have 32-bit UID/GID but didn't in the past 138 */ 139 140 int overflowuid = DEFAULT_OVERFLOWUID; 141 int overflowgid = DEFAULT_OVERFLOWGID; 142 143 EXPORT_SYMBOL(overflowuid); 144 EXPORT_SYMBOL(overflowgid); 145 146 /* 147 * the same as above, but for filesystems which can only store a 16-bit 148 * UID and GID. as such, this is needed on all architectures 149 */ 150 151 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 152 int fs_overflowgid = DEFAULT_FS_OVERFLOWGID; 153 154 EXPORT_SYMBOL(fs_overflowuid); 155 EXPORT_SYMBOL(fs_overflowgid); 156 157 /* 158 * Returns true if current's euid is same as p's uid or euid, 159 * or has CAP_SYS_NICE to p's user_ns. 160 * 161 * Called with rcu_read_lock, creds are safe 162 */ 163 static bool set_one_prio_perm(struct task_struct *p) 164 { 165 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 166 167 if (uid_eq(pcred->uid, cred->euid) || 168 uid_eq(pcred->euid, cred->euid)) 169 return true; 170 if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) 171 return true; 172 return false; 173 } 174 175 /* 176 * set the priority of a task 177 * - the caller must hold the RCU read lock 178 */ 179 static int set_one_prio(struct task_struct *p, int niceval, int error) 180 { 181 int no_nice; 182 183 if (!set_one_prio_perm(p)) { 184 error = -EPERM; 185 goto out; 186 } 187 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 188 error = -EACCES; 189 goto out; 190 } 191 no_nice = security_task_setnice(p, niceval); 192 if (no_nice) { 193 error = no_nice; 194 goto out; 195 } 196 if (error == -ESRCH) 197 error = 0; 198 set_user_nice(p, niceval); 199 out: 200 return error; 201 } 202 203 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 204 { 205 struct task_struct *g, *p; 206 struct user_struct *user; 207 const struct cred *cred = current_cred(); 208 int error = -EINVAL; 209 struct pid *pgrp; 210 kuid_t uid; 211 212 if (which > PRIO_USER || which < PRIO_PROCESS) 213 goto out; 214 215 /* normalize: avoid signed division (rounding problems) */ 216 error = -ESRCH; 217 if (niceval < MIN_NICE) 218 niceval = MIN_NICE; 219 if (niceval > MAX_NICE) 220 niceval = MAX_NICE; 221 222 rcu_read_lock(); 223 switch (which) { 224 case PRIO_PROCESS: 225 if (who) 226 p = find_task_by_vpid(who); 227 else 228 p = current; 229 if (p) 230 error = set_one_prio(p, niceval, error); 231 break; 232 case PRIO_PGRP: 233 if (who) 234 pgrp = find_vpid(who); 235 else 236 pgrp = task_pgrp(current); 237 read_lock(&tasklist_lock); 238 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 239 error = set_one_prio(p, niceval, error); 240 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 241 read_unlock(&tasklist_lock); 242 break; 243 case PRIO_USER: 244 uid = make_kuid(cred->user_ns, who); 245 user = cred->user; 246 if (!who) 247 uid = cred->uid; 248 else if (!uid_eq(uid, cred->uid)) { 249 user = find_user(uid); 250 if (!user) 251 goto out_unlock; /* No processes for this user */ 252 } 253 for_each_process_thread(g, p) { 254 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) 255 error = set_one_prio(p, niceval, error); 256 } 257 if (!uid_eq(uid, cred->uid)) 258 free_uid(user); /* For find_user() */ 259 break; 260 } 261 out_unlock: 262 rcu_read_unlock(); 263 out: 264 return error; 265 } 266 267 /* 268 * Ugh. To avoid negative return values, "getpriority()" will 269 * not return the normal nice-value, but a negated value that 270 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 271 * to stay compatible. 272 */ 273 SYSCALL_DEFINE2(getpriority, int, which, int, who) 274 { 275 struct task_struct *g, *p; 276 struct user_struct *user; 277 const struct cred *cred = current_cred(); 278 long niceval, retval = -ESRCH; 279 struct pid *pgrp; 280 kuid_t uid; 281 282 if (which > PRIO_USER || which < PRIO_PROCESS) 283 return -EINVAL; 284 285 rcu_read_lock(); 286 switch (which) { 287 case PRIO_PROCESS: 288 if (who) 289 p = find_task_by_vpid(who); 290 else 291 p = current; 292 if (p) { 293 niceval = nice_to_rlimit(task_nice(p)); 294 if (niceval > retval) 295 retval = niceval; 296 } 297 break; 298 case PRIO_PGRP: 299 if (who) 300 pgrp = find_vpid(who); 301 else 302 pgrp = task_pgrp(current); 303 read_lock(&tasklist_lock); 304 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 305 niceval = nice_to_rlimit(task_nice(p)); 306 if (niceval > retval) 307 retval = niceval; 308 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 309 read_unlock(&tasklist_lock); 310 break; 311 case PRIO_USER: 312 uid = make_kuid(cred->user_ns, who); 313 user = cred->user; 314 if (!who) 315 uid = cred->uid; 316 else if (!uid_eq(uid, cred->uid)) { 317 user = find_user(uid); 318 if (!user) 319 goto out_unlock; /* No processes for this user */ 320 } 321 for_each_process_thread(g, p) { 322 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) { 323 niceval = nice_to_rlimit(task_nice(p)); 324 if (niceval > retval) 325 retval = niceval; 326 } 327 } 328 if (!uid_eq(uid, cred->uid)) 329 free_uid(user); /* for find_user() */ 330 break; 331 } 332 out_unlock: 333 rcu_read_unlock(); 334 335 return retval; 336 } 337 338 /* 339 * Unprivileged users may change the real gid to the effective gid 340 * or vice versa. (BSD-style) 341 * 342 * If you set the real gid at all, or set the effective gid to a value not 343 * equal to the real gid, then the saved gid is set to the new effective gid. 344 * 345 * This makes it possible for a setgid program to completely drop its 346 * privileges, which is often a useful assertion to make when you are doing 347 * a security audit over a program. 348 * 349 * The general idea is that a program which uses just setregid() will be 350 * 100% compatible with BSD. A program which uses just setgid() will be 351 * 100% compatible with POSIX with saved IDs. 352 * 353 * SMP: There are not races, the GIDs are checked only by filesystem 354 * operations (as far as semantic preservation is concerned). 355 */ 356 #ifdef CONFIG_MULTIUSER 357 long __sys_setregid(gid_t rgid, gid_t egid) 358 { 359 struct user_namespace *ns = current_user_ns(); 360 const struct cred *old; 361 struct cred *new; 362 int retval; 363 kgid_t krgid, kegid; 364 365 krgid = make_kgid(ns, rgid); 366 kegid = make_kgid(ns, egid); 367 368 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 369 return -EINVAL; 370 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 371 return -EINVAL; 372 373 new = prepare_creds(); 374 if (!new) 375 return -ENOMEM; 376 old = current_cred(); 377 378 retval = -EPERM; 379 if (rgid != (gid_t) -1) { 380 if (gid_eq(old->gid, krgid) || 381 gid_eq(old->egid, krgid) || 382 ns_capable_setid(old->user_ns, CAP_SETGID)) 383 new->gid = krgid; 384 else 385 goto error; 386 } 387 if (egid != (gid_t) -1) { 388 if (gid_eq(old->gid, kegid) || 389 gid_eq(old->egid, kegid) || 390 gid_eq(old->sgid, kegid) || 391 ns_capable_setid(old->user_ns, CAP_SETGID)) 392 new->egid = kegid; 393 else 394 goto error; 395 } 396 397 if (rgid != (gid_t) -1 || 398 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) 399 new->sgid = new->egid; 400 new->fsgid = new->egid; 401 402 retval = security_task_fix_setgid(new, old, LSM_SETID_RE); 403 if (retval < 0) 404 goto error; 405 406 return commit_creds(new); 407 408 error: 409 abort_creds(new); 410 return retval; 411 } 412 413 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 414 { 415 return __sys_setregid(rgid, egid); 416 } 417 418 /* 419 * setgid() is implemented like SysV w/ SAVED_IDS 420 * 421 * SMP: Same implicit races as above. 422 */ 423 long __sys_setgid(gid_t gid) 424 { 425 struct user_namespace *ns = current_user_ns(); 426 const struct cred *old; 427 struct cred *new; 428 int retval; 429 kgid_t kgid; 430 431 kgid = make_kgid(ns, gid); 432 if (!gid_valid(kgid)) 433 return -EINVAL; 434 435 new = prepare_creds(); 436 if (!new) 437 return -ENOMEM; 438 old = current_cred(); 439 440 retval = -EPERM; 441 if (ns_capable_setid(old->user_ns, CAP_SETGID)) 442 new->gid = new->egid = new->sgid = new->fsgid = kgid; 443 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) 444 new->egid = new->fsgid = kgid; 445 else 446 goto error; 447 448 retval = security_task_fix_setgid(new, old, LSM_SETID_ID); 449 if (retval < 0) 450 goto error; 451 452 return commit_creds(new); 453 454 error: 455 abort_creds(new); 456 return retval; 457 } 458 459 SYSCALL_DEFINE1(setgid, gid_t, gid) 460 { 461 return __sys_setgid(gid); 462 } 463 464 /* 465 * change the user struct in a credentials set to match the new UID 466 */ 467 static int set_user(struct cred *new) 468 { 469 struct user_struct *new_user; 470 471 new_user = alloc_uid(new->uid); 472 if (!new_user) 473 return -EAGAIN; 474 475 free_uid(new->user); 476 new->user = new_user; 477 return 0; 478 } 479 480 static void flag_nproc_exceeded(struct cred *new) 481 { 482 if (new->ucounts == current_ucounts()) 483 return; 484 485 /* 486 * We don't fail in case of NPROC limit excess here because too many 487 * poorly written programs don't check set*uid() return code, assuming 488 * it never fails if called by root. We may still enforce NPROC limit 489 * for programs doing set*uid()+execve() by harmlessly deferring the 490 * failure to the execve() stage. 491 */ 492 if (is_ucounts_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) && 493 new->user != INIT_USER) 494 current->flags |= PF_NPROC_EXCEEDED; 495 else 496 current->flags &= ~PF_NPROC_EXCEEDED; 497 } 498 499 /* 500 * Unprivileged users may change the real uid to the effective uid 501 * or vice versa. (BSD-style) 502 * 503 * If you set the real uid at all, or set the effective uid to a value not 504 * equal to the real uid, then the saved uid is set to the new effective uid. 505 * 506 * This makes it possible for a setuid program to completely drop its 507 * privileges, which is often a useful assertion to make when you are doing 508 * a security audit over a program. 509 * 510 * The general idea is that a program which uses just setreuid() will be 511 * 100% compatible with BSD. A program which uses just setuid() will be 512 * 100% compatible with POSIX with saved IDs. 513 */ 514 long __sys_setreuid(uid_t ruid, uid_t euid) 515 { 516 struct user_namespace *ns = current_user_ns(); 517 const struct cred *old; 518 struct cred *new; 519 int retval; 520 kuid_t kruid, keuid; 521 522 kruid = make_kuid(ns, ruid); 523 keuid = make_kuid(ns, euid); 524 525 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 526 return -EINVAL; 527 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 528 return -EINVAL; 529 530 new = prepare_creds(); 531 if (!new) 532 return -ENOMEM; 533 old = current_cred(); 534 535 retval = -EPERM; 536 if (ruid != (uid_t) -1) { 537 new->uid = kruid; 538 if (!uid_eq(old->uid, kruid) && 539 !uid_eq(old->euid, kruid) && 540 !ns_capable_setid(old->user_ns, CAP_SETUID)) 541 goto error; 542 } 543 544 if (euid != (uid_t) -1) { 545 new->euid = keuid; 546 if (!uid_eq(old->uid, keuid) && 547 !uid_eq(old->euid, keuid) && 548 !uid_eq(old->suid, keuid) && 549 !ns_capable_setid(old->user_ns, CAP_SETUID)) 550 goto error; 551 } 552 553 if (!uid_eq(new->uid, old->uid)) { 554 retval = set_user(new); 555 if (retval < 0) 556 goto error; 557 } 558 if (ruid != (uid_t) -1 || 559 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) 560 new->suid = new->euid; 561 new->fsuid = new->euid; 562 563 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 564 if (retval < 0) 565 goto error; 566 567 retval = set_cred_ucounts(new); 568 if (retval < 0) 569 goto error; 570 571 flag_nproc_exceeded(new); 572 return commit_creds(new); 573 574 error: 575 abort_creds(new); 576 return retval; 577 } 578 579 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 580 { 581 return __sys_setreuid(ruid, euid); 582 } 583 584 /* 585 * setuid() is implemented like SysV with SAVED_IDS 586 * 587 * Note that SAVED_ID's is deficient in that a setuid root program 588 * like sendmail, for example, cannot set its uid to be a normal 589 * user and then switch back, because if you're root, setuid() sets 590 * the saved uid too. If you don't like this, blame the bright people 591 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 592 * will allow a root program to temporarily drop privileges and be able to 593 * regain them by swapping the real and effective uid. 594 */ 595 long __sys_setuid(uid_t uid) 596 { 597 struct user_namespace *ns = current_user_ns(); 598 const struct cred *old; 599 struct cred *new; 600 int retval; 601 kuid_t kuid; 602 603 kuid = make_kuid(ns, uid); 604 if (!uid_valid(kuid)) 605 return -EINVAL; 606 607 new = prepare_creds(); 608 if (!new) 609 return -ENOMEM; 610 old = current_cred(); 611 612 retval = -EPERM; 613 if (ns_capable_setid(old->user_ns, CAP_SETUID)) { 614 new->suid = new->uid = kuid; 615 if (!uid_eq(kuid, old->uid)) { 616 retval = set_user(new); 617 if (retval < 0) 618 goto error; 619 } 620 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { 621 goto error; 622 } 623 624 new->fsuid = new->euid = kuid; 625 626 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 627 if (retval < 0) 628 goto error; 629 630 retval = set_cred_ucounts(new); 631 if (retval < 0) 632 goto error; 633 634 flag_nproc_exceeded(new); 635 return commit_creds(new); 636 637 error: 638 abort_creds(new); 639 return retval; 640 } 641 642 SYSCALL_DEFINE1(setuid, uid_t, uid) 643 { 644 return __sys_setuid(uid); 645 } 646 647 648 /* 649 * This function implements a generic ability to update ruid, euid, 650 * and suid. This allows you to implement the 4.4 compatible seteuid(). 651 */ 652 long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) 653 { 654 struct user_namespace *ns = current_user_ns(); 655 const struct cred *old; 656 struct cred *new; 657 int retval; 658 kuid_t kruid, keuid, ksuid; 659 660 kruid = make_kuid(ns, ruid); 661 keuid = make_kuid(ns, euid); 662 ksuid = make_kuid(ns, suid); 663 664 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 665 return -EINVAL; 666 667 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 668 return -EINVAL; 669 670 if ((suid != (uid_t) -1) && !uid_valid(ksuid)) 671 return -EINVAL; 672 673 new = prepare_creds(); 674 if (!new) 675 return -ENOMEM; 676 677 old = current_cred(); 678 679 retval = -EPERM; 680 if (!ns_capable_setid(old->user_ns, CAP_SETUID)) { 681 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && 682 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid)) 683 goto error; 684 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && 685 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid)) 686 goto error; 687 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && 688 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid)) 689 goto error; 690 } 691 692 if (ruid != (uid_t) -1) { 693 new->uid = kruid; 694 if (!uid_eq(kruid, old->uid)) { 695 retval = set_user(new); 696 if (retval < 0) 697 goto error; 698 } 699 } 700 if (euid != (uid_t) -1) 701 new->euid = keuid; 702 if (suid != (uid_t) -1) 703 new->suid = ksuid; 704 new->fsuid = new->euid; 705 706 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 707 if (retval < 0) 708 goto error; 709 710 retval = set_cred_ucounts(new); 711 if (retval < 0) 712 goto error; 713 714 flag_nproc_exceeded(new); 715 return commit_creds(new); 716 717 error: 718 abort_creds(new); 719 return retval; 720 } 721 722 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 723 { 724 return __sys_setresuid(ruid, euid, suid); 725 } 726 727 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) 728 { 729 const struct cred *cred = current_cred(); 730 int retval; 731 uid_t ruid, euid, suid; 732 733 ruid = from_kuid_munged(cred->user_ns, cred->uid); 734 euid = from_kuid_munged(cred->user_ns, cred->euid); 735 suid = from_kuid_munged(cred->user_ns, cred->suid); 736 737 retval = put_user(ruid, ruidp); 738 if (!retval) { 739 retval = put_user(euid, euidp); 740 if (!retval) 741 return put_user(suid, suidp); 742 } 743 return retval; 744 } 745 746 /* 747 * Same as above, but for rgid, egid, sgid. 748 */ 749 long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) 750 { 751 struct user_namespace *ns = current_user_ns(); 752 const struct cred *old; 753 struct cred *new; 754 int retval; 755 kgid_t krgid, kegid, ksgid; 756 757 krgid = make_kgid(ns, rgid); 758 kegid = make_kgid(ns, egid); 759 ksgid = make_kgid(ns, sgid); 760 761 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 762 return -EINVAL; 763 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 764 return -EINVAL; 765 if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) 766 return -EINVAL; 767 768 new = prepare_creds(); 769 if (!new) 770 return -ENOMEM; 771 old = current_cred(); 772 773 retval = -EPERM; 774 if (!ns_capable_setid(old->user_ns, CAP_SETGID)) { 775 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && 776 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid)) 777 goto error; 778 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && 779 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid)) 780 goto error; 781 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && 782 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid)) 783 goto error; 784 } 785 786 if (rgid != (gid_t) -1) 787 new->gid = krgid; 788 if (egid != (gid_t) -1) 789 new->egid = kegid; 790 if (sgid != (gid_t) -1) 791 new->sgid = ksgid; 792 new->fsgid = new->egid; 793 794 retval = security_task_fix_setgid(new, old, LSM_SETID_RES); 795 if (retval < 0) 796 goto error; 797 798 return commit_creds(new); 799 800 error: 801 abort_creds(new); 802 return retval; 803 } 804 805 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 806 { 807 return __sys_setresgid(rgid, egid, sgid); 808 } 809 810 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) 811 { 812 const struct cred *cred = current_cred(); 813 int retval; 814 gid_t rgid, egid, sgid; 815 816 rgid = from_kgid_munged(cred->user_ns, cred->gid); 817 egid = from_kgid_munged(cred->user_ns, cred->egid); 818 sgid = from_kgid_munged(cred->user_ns, cred->sgid); 819 820 retval = put_user(rgid, rgidp); 821 if (!retval) { 822 retval = put_user(egid, egidp); 823 if (!retval) 824 retval = put_user(sgid, sgidp); 825 } 826 827 return retval; 828 } 829 830 831 /* 832 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 833 * is used for "access()" and for the NFS daemon (letting nfsd stay at 834 * whatever uid it wants to). It normally shadows "euid", except when 835 * explicitly set by setfsuid() or for access.. 836 */ 837 long __sys_setfsuid(uid_t uid) 838 { 839 const struct cred *old; 840 struct cred *new; 841 uid_t old_fsuid; 842 kuid_t kuid; 843 844 old = current_cred(); 845 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); 846 847 kuid = make_kuid(old->user_ns, uid); 848 if (!uid_valid(kuid)) 849 return old_fsuid; 850 851 new = prepare_creds(); 852 if (!new) 853 return old_fsuid; 854 855 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || 856 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || 857 ns_capable_setid(old->user_ns, CAP_SETUID)) { 858 if (!uid_eq(kuid, old->fsuid)) { 859 new->fsuid = kuid; 860 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 861 goto change_okay; 862 } 863 } 864 865 abort_creds(new); 866 return old_fsuid; 867 868 change_okay: 869 commit_creds(new); 870 return old_fsuid; 871 } 872 873 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 874 { 875 return __sys_setfsuid(uid); 876 } 877 878 /* 879 * Samma på svenska.. 880 */ 881 long __sys_setfsgid(gid_t gid) 882 { 883 const struct cred *old; 884 struct cred *new; 885 gid_t old_fsgid; 886 kgid_t kgid; 887 888 old = current_cred(); 889 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); 890 891 kgid = make_kgid(old->user_ns, gid); 892 if (!gid_valid(kgid)) 893 return old_fsgid; 894 895 new = prepare_creds(); 896 if (!new) 897 return old_fsgid; 898 899 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || 900 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || 901 ns_capable_setid(old->user_ns, CAP_SETGID)) { 902 if (!gid_eq(kgid, old->fsgid)) { 903 new->fsgid = kgid; 904 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0) 905 goto change_okay; 906 } 907 } 908 909 abort_creds(new); 910 return old_fsgid; 911 912 change_okay: 913 commit_creds(new); 914 return old_fsgid; 915 } 916 917 SYSCALL_DEFINE1(setfsgid, gid_t, gid) 918 { 919 return __sys_setfsgid(gid); 920 } 921 #endif /* CONFIG_MULTIUSER */ 922 923 /** 924 * sys_getpid - return the thread group id of the current process 925 * 926 * Note, despite the name, this returns the tgid not the pid. The tgid and 927 * the pid are identical unless CLONE_THREAD was specified on clone() in 928 * which case the tgid is the same in all threads of the same group. 929 * 930 * This is SMP safe as current->tgid does not change. 931 */ 932 SYSCALL_DEFINE0(getpid) 933 { 934 return task_tgid_vnr(current); 935 } 936 937 /* Thread ID - the internal kernel "pid" */ 938 SYSCALL_DEFINE0(gettid) 939 { 940 return task_pid_vnr(current); 941 } 942 943 /* 944 * Accessing ->real_parent is not SMP-safe, it could 945 * change from under us. However, we can use a stale 946 * value of ->real_parent under rcu_read_lock(), see 947 * release_task()->call_rcu(delayed_put_task_struct). 948 */ 949 SYSCALL_DEFINE0(getppid) 950 { 951 int pid; 952 953 rcu_read_lock(); 954 pid = task_tgid_vnr(rcu_dereference(current->real_parent)); 955 rcu_read_unlock(); 956 957 return pid; 958 } 959 960 SYSCALL_DEFINE0(getuid) 961 { 962 /* Only we change this so SMP safe */ 963 return from_kuid_munged(current_user_ns(), current_uid()); 964 } 965 966 SYSCALL_DEFINE0(geteuid) 967 { 968 /* Only we change this so SMP safe */ 969 return from_kuid_munged(current_user_ns(), current_euid()); 970 } 971 972 SYSCALL_DEFINE0(getgid) 973 { 974 /* Only we change this so SMP safe */ 975 return from_kgid_munged(current_user_ns(), current_gid()); 976 } 977 978 SYSCALL_DEFINE0(getegid) 979 { 980 /* Only we change this so SMP safe */ 981 return from_kgid_munged(current_user_ns(), current_egid()); 982 } 983 984 static void do_sys_times(struct tms *tms) 985 { 986 u64 tgutime, tgstime, cutime, cstime; 987 988 thread_group_cputime_adjusted(current, &tgutime, &tgstime); 989 cutime = current->signal->cutime; 990 cstime = current->signal->cstime; 991 tms->tms_utime = nsec_to_clock_t(tgutime); 992 tms->tms_stime = nsec_to_clock_t(tgstime); 993 tms->tms_cutime = nsec_to_clock_t(cutime); 994 tms->tms_cstime = nsec_to_clock_t(cstime); 995 } 996 997 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 998 { 999 if (tbuf) { 1000 struct tms tmp; 1001 1002 do_sys_times(&tmp); 1003 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 1004 return -EFAULT; 1005 } 1006 force_successful_syscall_return(); 1007 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 1008 } 1009 1010 #ifdef CONFIG_COMPAT 1011 static compat_clock_t clock_t_to_compat_clock_t(clock_t x) 1012 { 1013 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x)); 1014 } 1015 1016 COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf) 1017 { 1018 if (tbuf) { 1019 struct tms tms; 1020 struct compat_tms tmp; 1021 1022 do_sys_times(&tms); 1023 /* Convert our struct tms to the compat version. */ 1024 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime); 1025 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime); 1026 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime); 1027 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime); 1028 if (copy_to_user(tbuf, &tmp, sizeof(tmp))) 1029 return -EFAULT; 1030 } 1031 force_successful_syscall_return(); 1032 return compat_jiffies_to_clock_t(jiffies); 1033 } 1034 #endif 1035 1036 /* 1037 * This needs some heavy checking ... 1038 * I just haven't the stomach for it. I also don't fully 1039 * understand sessions/pgrp etc. Let somebody who does explain it. 1040 * 1041 * OK, I think I have the protection semantics right.... this is really 1042 * only important on a multi-user system anyway, to make sure one user 1043 * can't send a signal to a process owned by another. -TYT, 12/12/91 1044 * 1045 * !PF_FORKNOEXEC check to conform completely to POSIX. 1046 */ 1047 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 1048 { 1049 struct task_struct *p; 1050 struct task_struct *group_leader = current->group_leader; 1051 struct pid *pgrp; 1052 int err; 1053 1054 if (!pid) 1055 pid = task_pid_vnr(group_leader); 1056 if (!pgid) 1057 pgid = pid; 1058 if (pgid < 0) 1059 return -EINVAL; 1060 rcu_read_lock(); 1061 1062 /* From this point forward we keep holding onto the tasklist lock 1063 * so that our parent does not change from under us. -DaveM 1064 */ 1065 write_lock_irq(&tasklist_lock); 1066 1067 err = -ESRCH; 1068 p = find_task_by_vpid(pid); 1069 if (!p) 1070 goto out; 1071 1072 err = -EINVAL; 1073 if (!thread_group_leader(p)) 1074 goto out; 1075 1076 if (same_thread_group(p->real_parent, group_leader)) { 1077 err = -EPERM; 1078 if (task_session(p) != task_session(group_leader)) 1079 goto out; 1080 err = -EACCES; 1081 if (!(p->flags & PF_FORKNOEXEC)) 1082 goto out; 1083 } else { 1084 err = -ESRCH; 1085 if (p != group_leader) 1086 goto out; 1087 } 1088 1089 err = -EPERM; 1090 if (p->signal->leader) 1091 goto out; 1092 1093 pgrp = task_pid(p); 1094 if (pgid != pid) { 1095 struct task_struct *g; 1096 1097 pgrp = find_vpid(pgid); 1098 g = pid_task(pgrp, PIDTYPE_PGID); 1099 if (!g || task_session(g) != task_session(group_leader)) 1100 goto out; 1101 } 1102 1103 err = security_task_setpgid(p, pgid); 1104 if (err) 1105 goto out; 1106 1107 if (task_pgrp(p) != pgrp) 1108 change_pid(p, PIDTYPE_PGID, pgrp); 1109 1110 err = 0; 1111 out: 1112 /* All paths lead to here, thus we are safe. -DaveM */ 1113 write_unlock_irq(&tasklist_lock); 1114 rcu_read_unlock(); 1115 return err; 1116 } 1117 1118 static int do_getpgid(pid_t pid) 1119 { 1120 struct task_struct *p; 1121 struct pid *grp; 1122 int retval; 1123 1124 rcu_read_lock(); 1125 if (!pid) 1126 grp = task_pgrp(current); 1127 else { 1128 retval = -ESRCH; 1129 p = find_task_by_vpid(pid); 1130 if (!p) 1131 goto out; 1132 grp = task_pgrp(p); 1133 if (!grp) 1134 goto out; 1135 1136 retval = security_task_getpgid(p); 1137 if (retval) 1138 goto out; 1139 } 1140 retval = pid_vnr(grp); 1141 out: 1142 rcu_read_unlock(); 1143 return retval; 1144 } 1145 1146 SYSCALL_DEFINE1(getpgid, pid_t, pid) 1147 { 1148 return do_getpgid(pid); 1149 } 1150 1151 #ifdef __ARCH_WANT_SYS_GETPGRP 1152 1153 SYSCALL_DEFINE0(getpgrp) 1154 { 1155 return do_getpgid(0); 1156 } 1157 1158 #endif 1159 1160 SYSCALL_DEFINE1(getsid, pid_t, pid) 1161 { 1162 struct task_struct *p; 1163 struct pid *sid; 1164 int retval; 1165 1166 rcu_read_lock(); 1167 if (!pid) 1168 sid = task_session(current); 1169 else { 1170 retval = -ESRCH; 1171 p = find_task_by_vpid(pid); 1172 if (!p) 1173 goto out; 1174 sid = task_session(p); 1175 if (!sid) 1176 goto out; 1177 1178 retval = security_task_getsid(p); 1179 if (retval) 1180 goto out; 1181 } 1182 retval = pid_vnr(sid); 1183 out: 1184 rcu_read_unlock(); 1185 return retval; 1186 } 1187 1188 static void set_special_pids(struct pid *pid) 1189 { 1190 struct task_struct *curr = current->group_leader; 1191 1192 if (task_session(curr) != pid) 1193 change_pid(curr, PIDTYPE_SID, pid); 1194 1195 if (task_pgrp(curr) != pid) 1196 change_pid(curr, PIDTYPE_PGID, pid); 1197 } 1198 1199 int ksys_setsid(void) 1200 { 1201 struct task_struct *group_leader = current->group_leader; 1202 struct pid *sid = task_pid(group_leader); 1203 pid_t session = pid_vnr(sid); 1204 int err = -EPERM; 1205 1206 write_lock_irq(&tasklist_lock); 1207 /* Fail if I am already a session leader */ 1208 if (group_leader->signal->leader) 1209 goto out; 1210 1211 /* Fail if a process group id already exists that equals the 1212 * proposed session id. 1213 */ 1214 if (pid_task(sid, PIDTYPE_PGID)) 1215 goto out; 1216 1217 group_leader->signal->leader = 1; 1218 set_special_pids(sid); 1219 1220 proc_clear_tty(group_leader); 1221 1222 err = session; 1223 out: 1224 write_unlock_irq(&tasklist_lock); 1225 if (err > 0) { 1226 proc_sid_connector(group_leader); 1227 sched_autogroup_create_attach(group_leader); 1228 } 1229 return err; 1230 } 1231 1232 SYSCALL_DEFINE0(setsid) 1233 { 1234 return ksys_setsid(); 1235 } 1236 1237 DECLARE_RWSEM(uts_sem); 1238 1239 #ifdef COMPAT_UTS_MACHINE 1240 #define override_architecture(name) \ 1241 (personality(current->personality) == PER_LINUX32 && \ 1242 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ 1243 sizeof(COMPAT_UTS_MACHINE))) 1244 #else 1245 #define override_architecture(name) 0 1246 #endif 1247 1248 /* 1249 * Work around broken programs that cannot handle "Linux 3.0". 1250 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 1251 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be 1252 * 2.6.60. 1253 */ 1254 static int override_release(char __user *release, size_t len) 1255 { 1256 int ret = 0; 1257 1258 if (current->personality & UNAME26) { 1259 const char *rest = UTS_RELEASE; 1260 char buf[65] = { 0 }; 1261 int ndots = 0; 1262 unsigned v; 1263 size_t copy; 1264 1265 while (*rest) { 1266 if (*rest == '.' && ++ndots >= 3) 1267 break; 1268 if (!isdigit(*rest) && *rest != '.') 1269 break; 1270 rest++; 1271 } 1272 v = LINUX_VERSION_PATCHLEVEL + 60; 1273 copy = clamp_t(size_t, len, 1, sizeof(buf)); 1274 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); 1275 ret = copy_to_user(release, buf, copy + 1); 1276 } 1277 return ret; 1278 } 1279 1280 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1281 { 1282 struct new_utsname tmp; 1283 1284 down_read(&uts_sem); 1285 memcpy(&tmp, utsname(), sizeof(tmp)); 1286 up_read(&uts_sem); 1287 if (copy_to_user(name, &tmp, sizeof(tmp))) 1288 return -EFAULT; 1289 1290 if (override_release(name->release, sizeof(name->release))) 1291 return -EFAULT; 1292 if (override_architecture(name)) 1293 return -EFAULT; 1294 return 0; 1295 } 1296 1297 #ifdef __ARCH_WANT_SYS_OLD_UNAME 1298 /* 1299 * Old cruft 1300 */ 1301 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) 1302 { 1303 struct old_utsname tmp; 1304 1305 if (!name) 1306 return -EFAULT; 1307 1308 down_read(&uts_sem); 1309 memcpy(&tmp, utsname(), sizeof(tmp)); 1310 up_read(&uts_sem); 1311 if (copy_to_user(name, &tmp, sizeof(tmp))) 1312 return -EFAULT; 1313 1314 if (override_release(name->release, sizeof(name->release))) 1315 return -EFAULT; 1316 if (override_architecture(name)) 1317 return -EFAULT; 1318 return 0; 1319 } 1320 1321 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) 1322 { 1323 struct oldold_utsname tmp; 1324 1325 if (!name) 1326 return -EFAULT; 1327 1328 memset(&tmp, 0, sizeof(tmp)); 1329 1330 down_read(&uts_sem); 1331 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN); 1332 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN); 1333 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN); 1334 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN); 1335 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN); 1336 up_read(&uts_sem); 1337 if (copy_to_user(name, &tmp, sizeof(tmp))) 1338 return -EFAULT; 1339 1340 if (override_architecture(name)) 1341 return -EFAULT; 1342 if (override_release(name->release, sizeof(name->release))) 1343 return -EFAULT; 1344 return 0; 1345 } 1346 #endif 1347 1348 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1349 { 1350 int errno; 1351 char tmp[__NEW_UTS_LEN]; 1352 1353 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1354 return -EPERM; 1355 1356 if (len < 0 || len > __NEW_UTS_LEN) 1357 return -EINVAL; 1358 errno = -EFAULT; 1359 if (!copy_from_user(tmp, name, len)) { 1360 struct new_utsname *u; 1361 1362 down_write(&uts_sem); 1363 u = utsname(); 1364 memcpy(u->nodename, tmp, len); 1365 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1366 errno = 0; 1367 uts_proc_notify(UTS_PROC_HOSTNAME); 1368 up_write(&uts_sem); 1369 } 1370 return errno; 1371 } 1372 1373 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1374 1375 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1376 { 1377 int i; 1378 struct new_utsname *u; 1379 char tmp[__NEW_UTS_LEN + 1]; 1380 1381 if (len < 0) 1382 return -EINVAL; 1383 down_read(&uts_sem); 1384 u = utsname(); 1385 i = 1 + strlen(u->nodename); 1386 if (i > len) 1387 i = len; 1388 memcpy(tmp, u->nodename, i); 1389 up_read(&uts_sem); 1390 if (copy_to_user(name, tmp, i)) 1391 return -EFAULT; 1392 return 0; 1393 } 1394 1395 #endif 1396 1397 /* 1398 * Only setdomainname; getdomainname can be implemented by calling 1399 * uname() 1400 */ 1401 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1402 { 1403 int errno; 1404 char tmp[__NEW_UTS_LEN]; 1405 1406 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1407 return -EPERM; 1408 if (len < 0 || len > __NEW_UTS_LEN) 1409 return -EINVAL; 1410 1411 errno = -EFAULT; 1412 if (!copy_from_user(tmp, name, len)) { 1413 struct new_utsname *u; 1414 1415 down_write(&uts_sem); 1416 u = utsname(); 1417 memcpy(u->domainname, tmp, len); 1418 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1419 errno = 0; 1420 uts_proc_notify(UTS_PROC_DOMAINNAME); 1421 up_write(&uts_sem); 1422 } 1423 return errno; 1424 } 1425 1426 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1427 { 1428 struct rlimit value; 1429 int ret; 1430 1431 ret = do_prlimit(current, resource, NULL, &value); 1432 if (!ret) 1433 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1434 1435 return ret; 1436 } 1437 1438 #ifdef CONFIG_COMPAT 1439 1440 COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource, 1441 struct compat_rlimit __user *, rlim) 1442 { 1443 struct rlimit r; 1444 struct compat_rlimit r32; 1445 1446 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit))) 1447 return -EFAULT; 1448 1449 if (r32.rlim_cur == COMPAT_RLIM_INFINITY) 1450 r.rlim_cur = RLIM_INFINITY; 1451 else 1452 r.rlim_cur = r32.rlim_cur; 1453 if (r32.rlim_max == COMPAT_RLIM_INFINITY) 1454 r.rlim_max = RLIM_INFINITY; 1455 else 1456 r.rlim_max = r32.rlim_max; 1457 return do_prlimit(current, resource, &r, NULL); 1458 } 1459 1460 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource, 1461 struct compat_rlimit __user *, rlim) 1462 { 1463 struct rlimit r; 1464 int ret; 1465 1466 ret = do_prlimit(current, resource, NULL, &r); 1467 if (!ret) { 1468 struct compat_rlimit r32; 1469 if (r.rlim_cur > COMPAT_RLIM_INFINITY) 1470 r32.rlim_cur = COMPAT_RLIM_INFINITY; 1471 else 1472 r32.rlim_cur = r.rlim_cur; 1473 if (r.rlim_max > COMPAT_RLIM_INFINITY) 1474 r32.rlim_max = COMPAT_RLIM_INFINITY; 1475 else 1476 r32.rlim_max = r.rlim_max; 1477 1478 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit))) 1479 return -EFAULT; 1480 } 1481 return ret; 1482 } 1483 1484 #endif 1485 1486 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1487 1488 /* 1489 * Back compatibility for getrlimit. Needed for some apps. 1490 */ 1491 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1492 struct rlimit __user *, rlim) 1493 { 1494 struct rlimit x; 1495 if (resource >= RLIM_NLIMITS) 1496 return -EINVAL; 1497 1498 resource = array_index_nospec(resource, RLIM_NLIMITS); 1499 task_lock(current->group_leader); 1500 x = current->signal->rlim[resource]; 1501 task_unlock(current->group_leader); 1502 if (x.rlim_cur > 0x7FFFFFFF) 1503 x.rlim_cur = 0x7FFFFFFF; 1504 if (x.rlim_max > 0x7FFFFFFF) 1505 x.rlim_max = 0x7FFFFFFF; 1506 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0; 1507 } 1508 1509 #ifdef CONFIG_COMPAT 1510 COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1511 struct compat_rlimit __user *, rlim) 1512 { 1513 struct rlimit r; 1514 1515 if (resource >= RLIM_NLIMITS) 1516 return -EINVAL; 1517 1518 resource = array_index_nospec(resource, RLIM_NLIMITS); 1519 task_lock(current->group_leader); 1520 r = current->signal->rlim[resource]; 1521 task_unlock(current->group_leader); 1522 if (r.rlim_cur > 0x7FFFFFFF) 1523 r.rlim_cur = 0x7FFFFFFF; 1524 if (r.rlim_max > 0x7FFFFFFF) 1525 r.rlim_max = 0x7FFFFFFF; 1526 1527 if (put_user(r.rlim_cur, &rlim->rlim_cur) || 1528 put_user(r.rlim_max, &rlim->rlim_max)) 1529 return -EFAULT; 1530 return 0; 1531 } 1532 #endif 1533 1534 #endif 1535 1536 static inline bool rlim64_is_infinity(__u64 rlim64) 1537 { 1538 #if BITS_PER_LONG < 64 1539 return rlim64 >= ULONG_MAX; 1540 #else 1541 return rlim64 == RLIM64_INFINITY; 1542 #endif 1543 } 1544 1545 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) 1546 { 1547 if (rlim->rlim_cur == RLIM_INFINITY) 1548 rlim64->rlim_cur = RLIM64_INFINITY; 1549 else 1550 rlim64->rlim_cur = rlim->rlim_cur; 1551 if (rlim->rlim_max == RLIM_INFINITY) 1552 rlim64->rlim_max = RLIM64_INFINITY; 1553 else 1554 rlim64->rlim_max = rlim->rlim_max; 1555 } 1556 1557 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) 1558 { 1559 if (rlim64_is_infinity(rlim64->rlim_cur)) 1560 rlim->rlim_cur = RLIM_INFINITY; 1561 else 1562 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; 1563 if (rlim64_is_infinity(rlim64->rlim_max)) 1564 rlim->rlim_max = RLIM_INFINITY; 1565 else 1566 rlim->rlim_max = (unsigned long)rlim64->rlim_max; 1567 } 1568 1569 /* make sure you are allowed to change @tsk limits before calling this */ 1570 int do_prlimit(struct task_struct *tsk, unsigned int resource, 1571 struct rlimit *new_rlim, struct rlimit *old_rlim) 1572 { 1573 struct rlimit *rlim; 1574 int retval = 0; 1575 1576 if (resource >= RLIM_NLIMITS) 1577 return -EINVAL; 1578 if (new_rlim) { 1579 if (new_rlim->rlim_cur > new_rlim->rlim_max) 1580 return -EINVAL; 1581 if (resource == RLIMIT_NOFILE && 1582 new_rlim->rlim_max > sysctl_nr_open) 1583 return -EPERM; 1584 } 1585 1586 /* protect tsk->signal and tsk->sighand from disappearing */ 1587 read_lock(&tasklist_lock); 1588 if (!tsk->sighand) { 1589 retval = -ESRCH; 1590 goto out; 1591 } 1592 1593 rlim = tsk->signal->rlim + resource; 1594 task_lock(tsk->group_leader); 1595 if (new_rlim) { 1596 /* Keep the capable check against init_user_ns until 1597 cgroups can contain all limits */ 1598 if (new_rlim->rlim_max > rlim->rlim_max && 1599 !capable(CAP_SYS_RESOURCE)) 1600 retval = -EPERM; 1601 if (!retval) 1602 retval = security_task_setrlimit(tsk, resource, new_rlim); 1603 } 1604 if (!retval) { 1605 if (old_rlim) 1606 *old_rlim = *rlim; 1607 if (new_rlim) 1608 *rlim = *new_rlim; 1609 } 1610 task_unlock(tsk->group_leader); 1611 1612 /* 1613 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not 1614 * infinite. In case of RLIM_INFINITY the posix CPU timer code 1615 * ignores the rlimit. 1616 */ 1617 if (!retval && new_rlim && resource == RLIMIT_CPU && 1618 new_rlim->rlim_cur != RLIM_INFINITY && 1619 IS_ENABLED(CONFIG_POSIX_TIMERS)) 1620 update_rlimit_cpu(tsk, new_rlim->rlim_cur); 1621 out: 1622 read_unlock(&tasklist_lock); 1623 return retval; 1624 } 1625 1626 /* rcu lock must be held */ 1627 static int check_prlimit_permission(struct task_struct *task, 1628 unsigned int flags) 1629 { 1630 const struct cred *cred = current_cred(), *tcred; 1631 bool id_match; 1632 1633 if (current == task) 1634 return 0; 1635 1636 tcred = __task_cred(task); 1637 id_match = (uid_eq(cred->uid, tcred->euid) && 1638 uid_eq(cred->uid, tcred->suid) && 1639 uid_eq(cred->uid, tcred->uid) && 1640 gid_eq(cred->gid, tcred->egid) && 1641 gid_eq(cred->gid, tcred->sgid) && 1642 gid_eq(cred->gid, tcred->gid)); 1643 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) 1644 return -EPERM; 1645 1646 return security_task_prlimit(cred, tcred, flags); 1647 } 1648 1649 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, 1650 const struct rlimit64 __user *, new_rlim, 1651 struct rlimit64 __user *, old_rlim) 1652 { 1653 struct rlimit64 old64, new64; 1654 struct rlimit old, new; 1655 struct task_struct *tsk; 1656 unsigned int checkflags = 0; 1657 int ret; 1658 1659 if (old_rlim) 1660 checkflags |= LSM_PRLIMIT_READ; 1661 1662 if (new_rlim) { 1663 if (copy_from_user(&new64, new_rlim, sizeof(new64))) 1664 return -EFAULT; 1665 rlim64_to_rlim(&new64, &new); 1666 checkflags |= LSM_PRLIMIT_WRITE; 1667 } 1668 1669 rcu_read_lock(); 1670 tsk = pid ? find_task_by_vpid(pid) : current; 1671 if (!tsk) { 1672 rcu_read_unlock(); 1673 return -ESRCH; 1674 } 1675 ret = check_prlimit_permission(tsk, checkflags); 1676 if (ret) { 1677 rcu_read_unlock(); 1678 return ret; 1679 } 1680 get_task_struct(tsk); 1681 rcu_read_unlock(); 1682 1683 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, 1684 old_rlim ? &old : NULL); 1685 1686 if (!ret && old_rlim) { 1687 rlim_to_rlim64(&old, &old64); 1688 if (copy_to_user(old_rlim, &old64, sizeof(old64))) 1689 ret = -EFAULT; 1690 } 1691 1692 put_task_struct(tsk); 1693 return ret; 1694 } 1695 1696 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1697 { 1698 struct rlimit new_rlim; 1699 1700 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1701 return -EFAULT; 1702 return do_prlimit(current, resource, &new_rlim, NULL); 1703 } 1704 1705 /* 1706 * It would make sense to put struct rusage in the task_struct, 1707 * except that would make the task_struct be *really big*. After 1708 * task_struct gets moved into malloc'ed memory, it would 1709 * make sense to do this. It will make moving the rest of the information 1710 * a lot simpler! (Which we're not doing right now because we're not 1711 * measuring them yet). 1712 * 1713 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1714 * races with threads incrementing their own counters. But since word 1715 * reads are atomic, we either get new values or old values and we don't 1716 * care which for the sums. We always take the siglock to protect reading 1717 * the c* fields from p->signal from races with exit.c updating those 1718 * fields when reaping, so a sample either gets all the additions of a 1719 * given child after it's reaped, or none so this sample is before reaping. 1720 * 1721 * Locking: 1722 * We need to take the siglock for CHILDEREN, SELF and BOTH 1723 * for the cases current multithreaded, non-current single threaded 1724 * non-current multithreaded. Thread traversal is now safe with 1725 * the siglock held. 1726 * Strictly speaking, we donot need to take the siglock if we are current and 1727 * single threaded, as no one else can take our signal_struct away, no one 1728 * else can reap the children to update signal->c* counters, and no one else 1729 * can race with the signal-> fields. If we do not take any lock, the 1730 * signal-> fields could be read out of order while another thread was just 1731 * exiting. So we should place a read memory barrier when we avoid the lock. 1732 * On the writer side, write memory barrier is implied in __exit_signal 1733 * as __exit_signal releases the siglock spinlock after updating the signal-> 1734 * fields. But we don't do this yet to keep things simple. 1735 * 1736 */ 1737 1738 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1739 { 1740 r->ru_nvcsw += t->nvcsw; 1741 r->ru_nivcsw += t->nivcsw; 1742 r->ru_minflt += t->min_flt; 1743 r->ru_majflt += t->maj_flt; 1744 r->ru_inblock += task_io_get_inblock(t); 1745 r->ru_oublock += task_io_get_oublock(t); 1746 } 1747 1748 void getrusage(struct task_struct *p, int who, struct rusage *r) 1749 { 1750 struct task_struct *t; 1751 unsigned long flags; 1752 u64 tgutime, tgstime, utime, stime; 1753 unsigned long maxrss = 0; 1754 1755 memset((char *)r, 0, sizeof (*r)); 1756 utime = stime = 0; 1757 1758 if (who == RUSAGE_THREAD) { 1759 task_cputime_adjusted(current, &utime, &stime); 1760 accumulate_thread_rusage(p, r); 1761 maxrss = p->signal->maxrss; 1762 goto out; 1763 } 1764 1765 if (!lock_task_sighand(p, &flags)) 1766 return; 1767 1768 switch (who) { 1769 case RUSAGE_BOTH: 1770 case RUSAGE_CHILDREN: 1771 utime = p->signal->cutime; 1772 stime = p->signal->cstime; 1773 r->ru_nvcsw = p->signal->cnvcsw; 1774 r->ru_nivcsw = p->signal->cnivcsw; 1775 r->ru_minflt = p->signal->cmin_flt; 1776 r->ru_majflt = p->signal->cmaj_flt; 1777 r->ru_inblock = p->signal->cinblock; 1778 r->ru_oublock = p->signal->coublock; 1779 maxrss = p->signal->cmaxrss; 1780 1781 if (who == RUSAGE_CHILDREN) 1782 break; 1783 fallthrough; 1784 1785 case RUSAGE_SELF: 1786 thread_group_cputime_adjusted(p, &tgutime, &tgstime); 1787 utime += tgutime; 1788 stime += tgstime; 1789 r->ru_nvcsw += p->signal->nvcsw; 1790 r->ru_nivcsw += p->signal->nivcsw; 1791 r->ru_minflt += p->signal->min_flt; 1792 r->ru_majflt += p->signal->maj_flt; 1793 r->ru_inblock += p->signal->inblock; 1794 r->ru_oublock += p->signal->oublock; 1795 if (maxrss < p->signal->maxrss) 1796 maxrss = p->signal->maxrss; 1797 t = p; 1798 do { 1799 accumulate_thread_rusage(t, r); 1800 } while_each_thread(p, t); 1801 break; 1802 1803 default: 1804 BUG(); 1805 } 1806 unlock_task_sighand(p, &flags); 1807 1808 out: 1809 r->ru_utime = ns_to_kernel_old_timeval(utime); 1810 r->ru_stime = ns_to_kernel_old_timeval(stime); 1811 1812 if (who != RUSAGE_CHILDREN) { 1813 struct mm_struct *mm = get_task_mm(p); 1814 1815 if (mm) { 1816 setmax_mm_hiwater_rss(&maxrss, mm); 1817 mmput(mm); 1818 } 1819 } 1820 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1821 } 1822 1823 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1824 { 1825 struct rusage r; 1826 1827 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1828 who != RUSAGE_THREAD) 1829 return -EINVAL; 1830 1831 getrusage(current, who, &r); 1832 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1833 } 1834 1835 #ifdef CONFIG_COMPAT 1836 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) 1837 { 1838 struct rusage r; 1839 1840 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1841 who != RUSAGE_THREAD) 1842 return -EINVAL; 1843 1844 getrusage(current, who, &r); 1845 return put_compat_rusage(&r, ru); 1846 } 1847 #endif 1848 1849 SYSCALL_DEFINE1(umask, int, mask) 1850 { 1851 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1852 return mask; 1853 } 1854 1855 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) 1856 { 1857 struct fd exe; 1858 struct inode *inode; 1859 int err; 1860 1861 exe = fdget(fd); 1862 if (!exe.file) 1863 return -EBADF; 1864 1865 inode = file_inode(exe.file); 1866 1867 /* 1868 * Because the original mm->exe_file points to executable file, make 1869 * sure that this one is executable as well, to avoid breaking an 1870 * overall picture. 1871 */ 1872 err = -EACCES; 1873 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path)) 1874 goto exit; 1875 1876 err = file_permission(exe.file, MAY_EXEC); 1877 if (err) 1878 goto exit; 1879 1880 err = replace_mm_exe_file(mm, exe.file); 1881 exit: 1882 fdput(exe); 1883 return err; 1884 } 1885 1886 /* 1887 * Check arithmetic relations of passed addresses. 1888 * 1889 * WARNING: we don't require any capability here so be very careful 1890 * in what is allowed for modification from userspace. 1891 */ 1892 static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map) 1893 { 1894 unsigned long mmap_max_addr = TASK_SIZE; 1895 int error = -EINVAL, i; 1896 1897 static const unsigned char offsets[] = { 1898 offsetof(struct prctl_mm_map, start_code), 1899 offsetof(struct prctl_mm_map, end_code), 1900 offsetof(struct prctl_mm_map, start_data), 1901 offsetof(struct prctl_mm_map, end_data), 1902 offsetof(struct prctl_mm_map, start_brk), 1903 offsetof(struct prctl_mm_map, brk), 1904 offsetof(struct prctl_mm_map, start_stack), 1905 offsetof(struct prctl_mm_map, arg_start), 1906 offsetof(struct prctl_mm_map, arg_end), 1907 offsetof(struct prctl_mm_map, env_start), 1908 offsetof(struct prctl_mm_map, env_end), 1909 }; 1910 1911 /* 1912 * Make sure the members are not somewhere outside 1913 * of allowed address space. 1914 */ 1915 for (i = 0; i < ARRAY_SIZE(offsets); i++) { 1916 u64 val = *(u64 *)((char *)prctl_map + offsets[i]); 1917 1918 if ((unsigned long)val >= mmap_max_addr || 1919 (unsigned long)val < mmap_min_addr) 1920 goto out; 1921 } 1922 1923 /* 1924 * Make sure the pairs are ordered. 1925 */ 1926 #define __prctl_check_order(__m1, __op, __m2) \ 1927 ((unsigned long)prctl_map->__m1 __op \ 1928 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL 1929 error = __prctl_check_order(start_code, <, end_code); 1930 error |= __prctl_check_order(start_data,<=, end_data); 1931 error |= __prctl_check_order(start_brk, <=, brk); 1932 error |= __prctl_check_order(arg_start, <=, arg_end); 1933 error |= __prctl_check_order(env_start, <=, env_end); 1934 if (error) 1935 goto out; 1936 #undef __prctl_check_order 1937 1938 error = -EINVAL; 1939 1940 /* 1941 * Neither we should allow to override limits if they set. 1942 */ 1943 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, 1944 prctl_map->start_brk, prctl_map->end_data, 1945 prctl_map->start_data)) 1946 goto out; 1947 1948 error = 0; 1949 out: 1950 return error; 1951 } 1952 1953 #ifdef CONFIG_CHECKPOINT_RESTORE 1954 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) 1955 { 1956 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; 1957 unsigned long user_auxv[AT_VECTOR_SIZE]; 1958 struct mm_struct *mm = current->mm; 1959 int error; 1960 1961 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 1962 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256); 1963 1964 if (opt == PR_SET_MM_MAP_SIZE) 1965 return put_user((unsigned int)sizeof(prctl_map), 1966 (unsigned int __user *)addr); 1967 1968 if (data_size != sizeof(prctl_map)) 1969 return -EINVAL; 1970 1971 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) 1972 return -EFAULT; 1973 1974 error = validate_prctl_map_addr(&prctl_map); 1975 if (error) 1976 return error; 1977 1978 if (prctl_map.auxv_size) { 1979 /* 1980 * Someone is trying to cheat the auxv vector. 1981 */ 1982 if (!prctl_map.auxv || 1983 prctl_map.auxv_size > sizeof(mm->saved_auxv)) 1984 return -EINVAL; 1985 1986 memset(user_auxv, 0, sizeof(user_auxv)); 1987 if (copy_from_user(user_auxv, 1988 (const void __user *)prctl_map.auxv, 1989 prctl_map.auxv_size)) 1990 return -EFAULT; 1991 1992 /* Last entry must be AT_NULL as specification requires */ 1993 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL; 1994 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL; 1995 } 1996 1997 if (prctl_map.exe_fd != (u32)-1) { 1998 /* 1999 * Check if the current user is checkpoint/restore capable. 2000 * At the time of this writing, it checks for CAP_SYS_ADMIN 2001 * or CAP_CHECKPOINT_RESTORE. 2002 * Note that a user with access to ptrace can masquerade an 2003 * arbitrary program as any executable, even setuid ones. 2004 * This may have implications in the tomoyo subsystem. 2005 */ 2006 if (!checkpoint_restore_ns_capable(current_user_ns())) 2007 return -EPERM; 2008 2009 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd); 2010 if (error) 2011 return error; 2012 } 2013 2014 /* 2015 * arg_lock protects concurrent updates but we still need mmap_lock for 2016 * read to exclude races with sys_brk. 2017 */ 2018 mmap_read_lock(mm); 2019 2020 /* 2021 * We don't validate if these members are pointing to 2022 * real present VMAs because application may have correspond 2023 * VMAs already unmapped and kernel uses these members for statistics 2024 * output in procfs mostly, except 2025 * 2026 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups 2027 * for VMAs when updating these members so anything wrong written 2028 * here cause kernel to swear at userspace program but won't lead 2029 * to any problem in kernel itself 2030 */ 2031 2032 spin_lock(&mm->arg_lock); 2033 mm->start_code = prctl_map.start_code; 2034 mm->end_code = prctl_map.end_code; 2035 mm->start_data = prctl_map.start_data; 2036 mm->end_data = prctl_map.end_data; 2037 mm->start_brk = prctl_map.start_brk; 2038 mm->brk = prctl_map.brk; 2039 mm->start_stack = prctl_map.start_stack; 2040 mm->arg_start = prctl_map.arg_start; 2041 mm->arg_end = prctl_map.arg_end; 2042 mm->env_start = prctl_map.env_start; 2043 mm->env_end = prctl_map.env_end; 2044 spin_unlock(&mm->arg_lock); 2045 2046 /* 2047 * Note this update of @saved_auxv is lockless thus 2048 * if someone reads this member in procfs while we're 2049 * updating -- it may get partly updated results. It's 2050 * known and acceptable trade off: we leave it as is to 2051 * not introduce additional locks here making the kernel 2052 * more complex. 2053 */ 2054 if (prctl_map.auxv_size) 2055 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); 2056 2057 mmap_read_unlock(mm); 2058 return 0; 2059 } 2060 #endif /* CONFIG_CHECKPOINT_RESTORE */ 2061 2062 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr, 2063 unsigned long len) 2064 { 2065 /* 2066 * This doesn't move the auxiliary vector itself since it's pinned to 2067 * mm_struct, but it permits filling the vector with new values. It's 2068 * up to the caller to provide sane values here, otherwise userspace 2069 * tools which use this vector might be unhappy. 2070 */ 2071 unsigned long user_auxv[AT_VECTOR_SIZE] = {}; 2072 2073 if (len > sizeof(user_auxv)) 2074 return -EINVAL; 2075 2076 if (copy_from_user(user_auxv, (const void __user *)addr, len)) 2077 return -EFAULT; 2078 2079 /* Make sure the last entry is always AT_NULL */ 2080 user_auxv[AT_VECTOR_SIZE - 2] = 0; 2081 user_auxv[AT_VECTOR_SIZE - 1] = 0; 2082 2083 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 2084 2085 task_lock(current); 2086 memcpy(mm->saved_auxv, user_auxv, len); 2087 task_unlock(current); 2088 2089 return 0; 2090 } 2091 2092 static int prctl_set_mm(int opt, unsigned long addr, 2093 unsigned long arg4, unsigned long arg5) 2094 { 2095 struct mm_struct *mm = current->mm; 2096 struct prctl_mm_map prctl_map = { 2097 .auxv = NULL, 2098 .auxv_size = 0, 2099 .exe_fd = -1, 2100 }; 2101 struct vm_area_struct *vma; 2102 int error; 2103 2104 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV && 2105 opt != PR_SET_MM_MAP && 2106 opt != PR_SET_MM_MAP_SIZE))) 2107 return -EINVAL; 2108 2109 #ifdef CONFIG_CHECKPOINT_RESTORE 2110 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE) 2111 return prctl_set_mm_map(opt, (const void __user *)addr, arg4); 2112 #endif 2113 2114 if (!capable(CAP_SYS_RESOURCE)) 2115 return -EPERM; 2116 2117 if (opt == PR_SET_MM_EXE_FILE) 2118 return prctl_set_mm_exe_file(mm, (unsigned int)addr); 2119 2120 if (opt == PR_SET_MM_AUXV) 2121 return prctl_set_auxv(mm, addr, arg4); 2122 2123 if (addr >= TASK_SIZE || addr < mmap_min_addr) 2124 return -EINVAL; 2125 2126 error = -EINVAL; 2127 2128 /* 2129 * arg_lock protects concurrent updates of arg boundaries, we need 2130 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr 2131 * validation. 2132 */ 2133 mmap_read_lock(mm); 2134 vma = find_vma(mm, addr); 2135 2136 spin_lock(&mm->arg_lock); 2137 prctl_map.start_code = mm->start_code; 2138 prctl_map.end_code = mm->end_code; 2139 prctl_map.start_data = mm->start_data; 2140 prctl_map.end_data = mm->end_data; 2141 prctl_map.start_brk = mm->start_brk; 2142 prctl_map.brk = mm->brk; 2143 prctl_map.start_stack = mm->start_stack; 2144 prctl_map.arg_start = mm->arg_start; 2145 prctl_map.arg_end = mm->arg_end; 2146 prctl_map.env_start = mm->env_start; 2147 prctl_map.env_end = mm->env_end; 2148 2149 switch (opt) { 2150 case PR_SET_MM_START_CODE: 2151 prctl_map.start_code = addr; 2152 break; 2153 case PR_SET_MM_END_CODE: 2154 prctl_map.end_code = addr; 2155 break; 2156 case PR_SET_MM_START_DATA: 2157 prctl_map.start_data = addr; 2158 break; 2159 case PR_SET_MM_END_DATA: 2160 prctl_map.end_data = addr; 2161 break; 2162 case PR_SET_MM_START_STACK: 2163 prctl_map.start_stack = addr; 2164 break; 2165 case PR_SET_MM_START_BRK: 2166 prctl_map.start_brk = addr; 2167 break; 2168 case PR_SET_MM_BRK: 2169 prctl_map.brk = addr; 2170 break; 2171 case PR_SET_MM_ARG_START: 2172 prctl_map.arg_start = addr; 2173 break; 2174 case PR_SET_MM_ARG_END: 2175 prctl_map.arg_end = addr; 2176 break; 2177 case PR_SET_MM_ENV_START: 2178 prctl_map.env_start = addr; 2179 break; 2180 case PR_SET_MM_ENV_END: 2181 prctl_map.env_end = addr; 2182 break; 2183 default: 2184 goto out; 2185 } 2186 2187 error = validate_prctl_map_addr(&prctl_map); 2188 if (error) 2189 goto out; 2190 2191 switch (opt) { 2192 /* 2193 * If command line arguments and environment 2194 * are placed somewhere else on stack, we can 2195 * set them up here, ARG_START/END to setup 2196 * command line arguments and ENV_START/END 2197 * for environment. 2198 */ 2199 case PR_SET_MM_START_STACK: 2200 case PR_SET_MM_ARG_START: 2201 case PR_SET_MM_ARG_END: 2202 case PR_SET_MM_ENV_START: 2203 case PR_SET_MM_ENV_END: 2204 if (!vma) { 2205 error = -EFAULT; 2206 goto out; 2207 } 2208 } 2209 2210 mm->start_code = prctl_map.start_code; 2211 mm->end_code = prctl_map.end_code; 2212 mm->start_data = prctl_map.start_data; 2213 mm->end_data = prctl_map.end_data; 2214 mm->start_brk = prctl_map.start_brk; 2215 mm->brk = prctl_map.brk; 2216 mm->start_stack = prctl_map.start_stack; 2217 mm->arg_start = prctl_map.arg_start; 2218 mm->arg_end = prctl_map.arg_end; 2219 mm->env_start = prctl_map.env_start; 2220 mm->env_end = prctl_map.env_end; 2221 2222 error = 0; 2223 out: 2224 spin_unlock(&mm->arg_lock); 2225 mmap_read_unlock(mm); 2226 return error; 2227 } 2228 2229 #ifdef CONFIG_CHECKPOINT_RESTORE 2230 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr) 2231 { 2232 return put_user(me->clear_child_tid, tid_addr); 2233 } 2234 #else 2235 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr) 2236 { 2237 return -EINVAL; 2238 } 2239 #endif 2240 2241 static int propagate_has_child_subreaper(struct task_struct *p, void *data) 2242 { 2243 /* 2244 * If task has has_child_subreaper - all its descendants 2245 * already have these flag too and new descendants will 2246 * inherit it on fork, skip them. 2247 * 2248 * If we've found child_reaper - skip descendants in 2249 * it's subtree as they will never get out pidns. 2250 */ 2251 if (p->signal->has_child_subreaper || 2252 is_child_reaper(task_pid(p))) 2253 return 0; 2254 2255 p->signal->has_child_subreaper = 1; 2256 return 1; 2257 } 2258 2259 int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which) 2260 { 2261 return -EINVAL; 2262 } 2263 2264 int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which, 2265 unsigned long ctrl) 2266 { 2267 return -EINVAL; 2268 } 2269 2270 #define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE) 2271 2272 #ifdef CONFIG_ANON_VMA_NAME 2273 2274 #define ANON_VMA_NAME_MAX_LEN 80 2275 #define ANON_VMA_NAME_INVALID_CHARS "\\`$[]" 2276 2277 static inline bool is_valid_name_char(char ch) 2278 { 2279 /* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */ 2280 return ch > 0x1f && ch < 0x7f && 2281 !strchr(ANON_VMA_NAME_INVALID_CHARS, ch); 2282 } 2283 2284 static int prctl_set_vma(unsigned long opt, unsigned long addr, 2285 unsigned long size, unsigned long arg) 2286 { 2287 struct mm_struct *mm = current->mm; 2288 const char __user *uname; 2289 char *name, *pch; 2290 int error; 2291 2292 switch (opt) { 2293 case PR_SET_VMA_ANON_NAME: 2294 uname = (const char __user *)arg; 2295 if (uname) { 2296 name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN); 2297 2298 if (IS_ERR(name)) 2299 return PTR_ERR(name); 2300 2301 for (pch = name; *pch != '\0'; pch++) { 2302 if (!is_valid_name_char(*pch)) { 2303 kfree(name); 2304 return -EINVAL; 2305 } 2306 } 2307 } else { 2308 /* Reset the name */ 2309 name = NULL; 2310 } 2311 2312 mmap_write_lock(mm); 2313 error = madvise_set_anon_name(mm, addr, size, name); 2314 mmap_write_unlock(mm); 2315 kfree(name); 2316 break; 2317 default: 2318 error = -EINVAL; 2319 } 2320 2321 return error; 2322 } 2323 2324 #else /* CONFIG_ANON_VMA_NAME */ 2325 static int prctl_set_vma(unsigned long opt, unsigned long start, 2326 unsigned long size, unsigned long arg) 2327 { 2328 return -EINVAL; 2329 } 2330 #endif /* CONFIG_ANON_VMA_NAME */ 2331 2332 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 2333 unsigned long, arg4, unsigned long, arg5) 2334 { 2335 struct task_struct *me = current; 2336 unsigned char comm[sizeof(me->comm)]; 2337 long error; 2338 2339 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 2340 if (error != -ENOSYS) 2341 return error; 2342 2343 error = 0; 2344 switch (option) { 2345 case PR_SET_PDEATHSIG: 2346 if (!valid_signal(arg2)) { 2347 error = -EINVAL; 2348 break; 2349 } 2350 me->pdeath_signal = arg2; 2351 break; 2352 case PR_GET_PDEATHSIG: 2353 error = put_user(me->pdeath_signal, (int __user *)arg2); 2354 break; 2355 case PR_GET_DUMPABLE: 2356 error = get_dumpable(me->mm); 2357 break; 2358 case PR_SET_DUMPABLE: 2359 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { 2360 error = -EINVAL; 2361 break; 2362 } 2363 set_dumpable(me->mm, arg2); 2364 break; 2365 2366 case PR_SET_UNALIGN: 2367 error = SET_UNALIGN_CTL(me, arg2); 2368 break; 2369 case PR_GET_UNALIGN: 2370 error = GET_UNALIGN_CTL(me, arg2); 2371 break; 2372 case PR_SET_FPEMU: 2373 error = SET_FPEMU_CTL(me, arg2); 2374 break; 2375 case PR_GET_FPEMU: 2376 error = GET_FPEMU_CTL(me, arg2); 2377 break; 2378 case PR_SET_FPEXC: 2379 error = SET_FPEXC_CTL(me, arg2); 2380 break; 2381 case PR_GET_FPEXC: 2382 error = GET_FPEXC_CTL(me, arg2); 2383 break; 2384 case PR_GET_TIMING: 2385 error = PR_TIMING_STATISTICAL; 2386 break; 2387 case PR_SET_TIMING: 2388 if (arg2 != PR_TIMING_STATISTICAL) 2389 error = -EINVAL; 2390 break; 2391 case PR_SET_NAME: 2392 comm[sizeof(me->comm) - 1] = 0; 2393 if (strncpy_from_user(comm, (char __user *)arg2, 2394 sizeof(me->comm) - 1) < 0) 2395 return -EFAULT; 2396 set_task_comm(me, comm); 2397 proc_comm_connector(me); 2398 break; 2399 case PR_GET_NAME: 2400 get_task_comm(comm, me); 2401 if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) 2402 return -EFAULT; 2403 break; 2404 case PR_GET_ENDIAN: 2405 error = GET_ENDIAN(me, arg2); 2406 break; 2407 case PR_SET_ENDIAN: 2408 error = SET_ENDIAN(me, arg2); 2409 break; 2410 case PR_GET_SECCOMP: 2411 error = prctl_get_seccomp(); 2412 break; 2413 case PR_SET_SECCOMP: 2414 error = prctl_set_seccomp(arg2, (char __user *)arg3); 2415 break; 2416 case PR_GET_TSC: 2417 error = GET_TSC_CTL(arg2); 2418 break; 2419 case PR_SET_TSC: 2420 error = SET_TSC_CTL(arg2); 2421 break; 2422 case PR_TASK_PERF_EVENTS_DISABLE: 2423 error = perf_event_task_disable(); 2424 break; 2425 case PR_TASK_PERF_EVENTS_ENABLE: 2426 error = perf_event_task_enable(); 2427 break; 2428 case PR_GET_TIMERSLACK: 2429 if (current->timer_slack_ns > ULONG_MAX) 2430 error = ULONG_MAX; 2431 else 2432 error = current->timer_slack_ns; 2433 break; 2434 case PR_SET_TIMERSLACK: 2435 if (arg2 <= 0) 2436 current->timer_slack_ns = 2437 current->default_timer_slack_ns; 2438 else 2439 current->timer_slack_ns = arg2; 2440 break; 2441 case PR_MCE_KILL: 2442 if (arg4 | arg5) 2443 return -EINVAL; 2444 switch (arg2) { 2445 case PR_MCE_KILL_CLEAR: 2446 if (arg3 != 0) 2447 return -EINVAL; 2448 current->flags &= ~PF_MCE_PROCESS; 2449 break; 2450 case PR_MCE_KILL_SET: 2451 current->flags |= PF_MCE_PROCESS; 2452 if (arg3 == PR_MCE_KILL_EARLY) 2453 current->flags |= PF_MCE_EARLY; 2454 else if (arg3 == PR_MCE_KILL_LATE) 2455 current->flags &= ~PF_MCE_EARLY; 2456 else if (arg3 == PR_MCE_KILL_DEFAULT) 2457 current->flags &= 2458 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 2459 else 2460 return -EINVAL; 2461 break; 2462 default: 2463 return -EINVAL; 2464 } 2465 break; 2466 case PR_MCE_KILL_GET: 2467 if (arg2 | arg3 | arg4 | arg5) 2468 return -EINVAL; 2469 if (current->flags & PF_MCE_PROCESS) 2470 error = (current->flags & PF_MCE_EARLY) ? 2471 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 2472 else 2473 error = PR_MCE_KILL_DEFAULT; 2474 break; 2475 case PR_SET_MM: 2476 error = prctl_set_mm(arg2, arg3, arg4, arg5); 2477 break; 2478 case PR_GET_TID_ADDRESS: 2479 error = prctl_get_tid_address(me, (int __user * __user *)arg2); 2480 break; 2481 case PR_SET_CHILD_SUBREAPER: 2482 me->signal->is_child_subreaper = !!arg2; 2483 if (!arg2) 2484 break; 2485 2486 walk_process_tree(me, propagate_has_child_subreaper, NULL); 2487 break; 2488 case PR_GET_CHILD_SUBREAPER: 2489 error = put_user(me->signal->is_child_subreaper, 2490 (int __user *)arg2); 2491 break; 2492 case PR_SET_NO_NEW_PRIVS: 2493 if (arg2 != 1 || arg3 || arg4 || arg5) 2494 return -EINVAL; 2495 2496 task_set_no_new_privs(current); 2497 break; 2498 case PR_GET_NO_NEW_PRIVS: 2499 if (arg2 || arg3 || arg4 || arg5) 2500 return -EINVAL; 2501 return task_no_new_privs(current) ? 1 : 0; 2502 case PR_GET_THP_DISABLE: 2503 if (arg2 || arg3 || arg4 || arg5) 2504 return -EINVAL; 2505 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags); 2506 break; 2507 case PR_SET_THP_DISABLE: 2508 if (arg3 || arg4 || arg5) 2509 return -EINVAL; 2510 if (mmap_write_lock_killable(me->mm)) 2511 return -EINTR; 2512 if (arg2) 2513 set_bit(MMF_DISABLE_THP, &me->mm->flags); 2514 else 2515 clear_bit(MMF_DISABLE_THP, &me->mm->flags); 2516 mmap_write_unlock(me->mm); 2517 break; 2518 case PR_MPX_ENABLE_MANAGEMENT: 2519 case PR_MPX_DISABLE_MANAGEMENT: 2520 /* No longer implemented: */ 2521 return -EINVAL; 2522 case PR_SET_FP_MODE: 2523 error = SET_FP_MODE(me, arg2); 2524 break; 2525 case PR_GET_FP_MODE: 2526 error = GET_FP_MODE(me); 2527 break; 2528 case PR_SVE_SET_VL: 2529 error = SVE_SET_VL(arg2); 2530 break; 2531 case PR_SVE_GET_VL: 2532 error = SVE_GET_VL(); 2533 break; 2534 case PR_GET_SPECULATION_CTRL: 2535 if (arg3 || arg4 || arg5) 2536 return -EINVAL; 2537 error = arch_prctl_spec_ctrl_get(me, arg2); 2538 break; 2539 case PR_SET_SPECULATION_CTRL: 2540 if (arg4 || arg5) 2541 return -EINVAL; 2542 error = arch_prctl_spec_ctrl_set(me, arg2, arg3); 2543 break; 2544 case PR_PAC_RESET_KEYS: 2545 if (arg3 || arg4 || arg5) 2546 return -EINVAL; 2547 error = PAC_RESET_KEYS(me, arg2); 2548 break; 2549 case PR_PAC_SET_ENABLED_KEYS: 2550 if (arg4 || arg5) 2551 return -EINVAL; 2552 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3); 2553 break; 2554 case PR_PAC_GET_ENABLED_KEYS: 2555 if (arg2 || arg3 || arg4 || arg5) 2556 return -EINVAL; 2557 error = PAC_GET_ENABLED_KEYS(me); 2558 break; 2559 case PR_SET_TAGGED_ADDR_CTRL: 2560 if (arg3 || arg4 || arg5) 2561 return -EINVAL; 2562 error = SET_TAGGED_ADDR_CTRL(arg2); 2563 break; 2564 case PR_GET_TAGGED_ADDR_CTRL: 2565 if (arg2 || arg3 || arg4 || arg5) 2566 return -EINVAL; 2567 error = GET_TAGGED_ADDR_CTRL(); 2568 break; 2569 case PR_SET_IO_FLUSHER: 2570 if (!capable(CAP_SYS_RESOURCE)) 2571 return -EPERM; 2572 2573 if (arg3 || arg4 || arg5) 2574 return -EINVAL; 2575 2576 if (arg2 == 1) 2577 current->flags |= PR_IO_FLUSHER; 2578 else if (!arg2) 2579 current->flags &= ~PR_IO_FLUSHER; 2580 else 2581 return -EINVAL; 2582 break; 2583 case PR_GET_IO_FLUSHER: 2584 if (!capable(CAP_SYS_RESOURCE)) 2585 return -EPERM; 2586 2587 if (arg2 || arg3 || arg4 || arg5) 2588 return -EINVAL; 2589 2590 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER; 2591 break; 2592 case PR_SET_SYSCALL_USER_DISPATCH: 2593 error = set_syscall_user_dispatch(arg2, arg3, arg4, 2594 (char __user *) arg5); 2595 break; 2596 #ifdef CONFIG_SCHED_CORE 2597 case PR_SCHED_CORE: 2598 error = sched_core_share_pid(arg2, arg3, arg4, arg5); 2599 break; 2600 #endif 2601 case PR_SET_VMA: 2602 error = prctl_set_vma(arg2, arg3, arg4, arg5); 2603 break; 2604 default: 2605 error = -EINVAL; 2606 break; 2607 } 2608 return error; 2609 } 2610 2611 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 2612 struct getcpu_cache __user *, unused) 2613 { 2614 int err = 0; 2615 int cpu = raw_smp_processor_id(); 2616 2617 if (cpup) 2618 err |= put_user(cpu, cpup); 2619 if (nodep) 2620 err |= put_user(cpu_to_node(cpu), nodep); 2621 return err ? -EFAULT : 0; 2622 } 2623 2624 /** 2625 * do_sysinfo - fill in sysinfo struct 2626 * @info: pointer to buffer to fill 2627 */ 2628 static int do_sysinfo(struct sysinfo *info) 2629 { 2630 unsigned long mem_total, sav_total; 2631 unsigned int mem_unit, bitcount; 2632 struct timespec64 tp; 2633 2634 memset(info, 0, sizeof(struct sysinfo)); 2635 2636 ktime_get_boottime_ts64(&tp); 2637 timens_add_boottime(&tp); 2638 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); 2639 2640 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); 2641 2642 info->procs = nr_threads; 2643 2644 si_meminfo(info); 2645 si_swapinfo(info); 2646 2647 /* 2648 * If the sum of all the available memory (i.e. ram + swap) 2649 * is less than can be stored in a 32 bit unsigned long then 2650 * we can be binary compatible with 2.2.x kernels. If not, 2651 * well, in that case 2.2.x was broken anyways... 2652 * 2653 * -Erik Andersen <andersee@debian.org> 2654 */ 2655 2656 mem_total = info->totalram + info->totalswap; 2657 if (mem_total < info->totalram || mem_total < info->totalswap) 2658 goto out; 2659 bitcount = 0; 2660 mem_unit = info->mem_unit; 2661 while (mem_unit > 1) { 2662 bitcount++; 2663 mem_unit >>= 1; 2664 sav_total = mem_total; 2665 mem_total <<= 1; 2666 if (mem_total < sav_total) 2667 goto out; 2668 } 2669 2670 /* 2671 * If mem_total did not overflow, multiply all memory values by 2672 * info->mem_unit and set it to 1. This leaves things compatible 2673 * with 2.2.x, and also retains compatibility with earlier 2.4.x 2674 * kernels... 2675 */ 2676 2677 info->mem_unit = 1; 2678 info->totalram <<= bitcount; 2679 info->freeram <<= bitcount; 2680 info->sharedram <<= bitcount; 2681 info->bufferram <<= bitcount; 2682 info->totalswap <<= bitcount; 2683 info->freeswap <<= bitcount; 2684 info->totalhigh <<= bitcount; 2685 info->freehigh <<= bitcount; 2686 2687 out: 2688 return 0; 2689 } 2690 2691 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) 2692 { 2693 struct sysinfo val; 2694 2695 do_sysinfo(&val); 2696 2697 if (copy_to_user(info, &val, sizeof(struct sysinfo))) 2698 return -EFAULT; 2699 2700 return 0; 2701 } 2702 2703 #ifdef CONFIG_COMPAT 2704 struct compat_sysinfo { 2705 s32 uptime; 2706 u32 loads[3]; 2707 u32 totalram; 2708 u32 freeram; 2709 u32 sharedram; 2710 u32 bufferram; 2711 u32 totalswap; 2712 u32 freeswap; 2713 u16 procs; 2714 u16 pad; 2715 u32 totalhigh; 2716 u32 freehigh; 2717 u32 mem_unit; 2718 char _f[20-2*sizeof(u32)-sizeof(int)]; 2719 }; 2720 2721 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) 2722 { 2723 struct sysinfo s; 2724 struct compat_sysinfo s_32; 2725 2726 do_sysinfo(&s); 2727 2728 /* Check to see if any memory value is too large for 32-bit and scale 2729 * down if needed 2730 */ 2731 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) { 2732 int bitcount = 0; 2733 2734 while (s.mem_unit < PAGE_SIZE) { 2735 s.mem_unit <<= 1; 2736 bitcount++; 2737 } 2738 2739 s.totalram >>= bitcount; 2740 s.freeram >>= bitcount; 2741 s.sharedram >>= bitcount; 2742 s.bufferram >>= bitcount; 2743 s.totalswap >>= bitcount; 2744 s.freeswap >>= bitcount; 2745 s.totalhigh >>= bitcount; 2746 s.freehigh >>= bitcount; 2747 } 2748 2749 memset(&s_32, 0, sizeof(s_32)); 2750 s_32.uptime = s.uptime; 2751 s_32.loads[0] = s.loads[0]; 2752 s_32.loads[1] = s.loads[1]; 2753 s_32.loads[2] = s.loads[2]; 2754 s_32.totalram = s.totalram; 2755 s_32.freeram = s.freeram; 2756 s_32.sharedram = s.sharedram; 2757 s_32.bufferram = s.bufferram; 2758 s_32.totalswap = s.totalswap; 2759 s_32.freeswap = s.freeswap; 2760 s_32.procs = s.procs; 2761 s_32.totalhigh = s.totalhigh; 2762 s_32.freehigh = s.freehigh; 2763 s_32.mem_unit = s.mem_unit; 2764 if (copy_to_user(info, &s_32, sizeof(s_32))) 2765 return -EFAULT; 2766 return 0; 2767 } 2768 #endif /* CONFIG_COMPAT */ 2769