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