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