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