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