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/mm_inline.h> 11 #include <linux/utsname.h> 12 #include <linux/mman.h> 13 #include <linux/reboot.h> 14 #include <linux/prctl.h> 15 #include <linux/highuid.h> 16 #include <linux/fs.h> 17 #include <linux/kmod.h> 18 #include <linux/ksm.h> 19 #include <linux/perf_event.h> 20 #include <linux/resource.h> 21 #include <linux/kernel.h> 22 #include <linux/workqueue.h> 23 #include <linux/capability.h> 24 #include <linux/device.h> 25 #include <linux/key.h> 26 #include <linux/times.h> 27 #include <linux/posix-timers.h> 28 #include <linux/security.h> 29 #include <linux/random.h> 30 #include <linux/suspend.h> 31 #include <linux/tty.h> 32 #include <linux/signal.h> 33 #include <linux/cn_proc.h> 34 #include <linux/task_io_accounting_ops.h> 35 #include <linux/seccomp.h> 36 #include <linux/cpu.h> 37 #include <linux/personality.h> 38 #include <linux/ptrace.h> 39 #include <linux/fs_struct.h> 40 #include <linux/file.h> 41 #include <linux/mount.h> 42 #include <linux/gfp.h> 43 #include <linux/syscore_ops.h> 44 #include <linux/version.h> 45 #include <linux/ctype.h> 46 #include <linux/syscall_user_dispatch.h> 47 48 #include <linux/compat.h> 49 #include <linux/syscalls.h> 50 #include <linux/kprobes.h> 51 #include <linux/user_namespace.h> 52 #include <linux/time_namespace.h> 53 #include <linux/binfmts.h> 54 #include <linux/futex.h> 55 56 #include <linux/sched.h> 57 #include <linux/sched/autogroup.h> 58 #include <linux/sched/loadavg.h> 59 #include <linux/sched/stat.h> 60 #include <linux/sched/mm.h> 61 #include <linux/sched/coredump.h> 62 #include <linux/sched/task.h> 63 #include <linux/sched/cputime.h> 64 #include <linux/rcupdate.h> 65 #include <linux/uidgid.h> 66 #include <linux/cred.h> 67 68 #include <linux/nospec.h> 69 70 #include <linux/kmsg_dump.h> 71 /* Move somewhere else to avoid recompiling? */ 72 #include <generated/utsrelease.h> 73 74 #include <linux/uaccess.h> 75 #include <asm/io.h> 76 #include <asm/unistd.h> 77 78 #include <trace/events/task.h> 79 80 #include "uid16.h" 81 82 #ifndef SET_UNALIGN_CTL 83 # define SET_UNALIGN_CTL(a, b) (-EINVAL) 84 #endif 85 #ifndef GET_UNALIGN_CTL 86 # define GET_UNALIGN_CTL(a, b) (-EINVAL) 87 #endif 88 #ifndef SET_FPEMU_CTL 89 # define SET_FPEMU_CTL(a, b) (-EINVAL) 90 #endif 91 #ifndef GET_FPEMU_CTL 92 # define GET_FPEMU_CTL(a, b) (-EINVAL) 93 #endif 94 #ifndef SET_FPEXC_CTL 95 # define SET_FPEXC_CTL(a, b) (-EINVAL) 96 #endif 97 #ifndef GET_FPEXC_CTL 98 # define GET_FPEXC_CTL(a, b) (-EINVAL) 99 #endif 100 #ifndef GET_ENDIAN 101 # define GET_ENDIAN(a, b) (-EINVAL) 102 #endif 103 #ifndef SET_ENDIAN 104 # define SET_ENDIAN(a, b) (-EINVAL) 105 #endif 106 #ifndef GET_TSC_CTL 107 # define GET_TSC_CTL(a) (-EINVAL) 108 #endif 109 #ifndef SET_TSC_CTL 110 # define SET_TSC_CTL(a) (-EINVAL) 111 #endif 112 #ifndef GET_FP_MODE 113 # define GET_FP_MODE(a) (-EINVAL) 114 #endif 115 #ifndef SET_FP_MODE 116 # define SET_FP_MODE(a,b) (-EINVAL) 117 #endif 118 #ifndef SVE_SET_VL 119 # define SVE_SET_VL(a) (-EINVAL) 120 #endif 121 #ifndef SVE_GET_VL 122 # define SVE_GET_VL() (-EINVAL) 123 #endif 124 #ifndef SME_SET_VL 125 # define SME_SET_VL(a) (-EINVAL) 126 #endif 127 #ifndef SME_GET_VL 128 # define SME_GET_VL() (-EINVAL) 129 #endif 130 #ifndef PAC_RESET_KEYS 131 # define PAC_RESET_KEYS(a, b) (-EINVAL) 132 #endif 133 #ifndef PAC_SET_ENABLED_KEYS 134 # define PAC_SET_ENABLED_KEYS(a, b, c) (-EINVAL) 135 #endif 136 #ifndef PAC_GET_ENABLED_KEYS 137 # define PAC_GET_ENABLED_KEYS(a) (-EINVAL) 138 #endif 139 #ifndef SET_TAGGED_ADDR_CTRL 140 # define SET_TAGGED_ADDR_CTRL(a) (-EINVAL) 141 #endif 142 #ifndef GET_TAGGED_ADDR_CTRL 143 # define GET_TAGGED_ADDR_CTRL() (-EINVAL) 144 #endif 145 #ifndef RISCV_V_SET_CONTROL 146 # define RISCV_V_SET_CONTROL(a) (-EINVAL) 147 #endif 148 #ifndef RISCV_V_GET_CONTROL 149 # define RISCV_V_GET_CONTROL() (-EINVAL) 150 #endif 151 #ifndef RISCV_SET_ICACHE_FLUSH_CTX 152 # define RISCV_SET_ICACHE_FLUSH_CTX(a, b) (-EINVAL) 153 #endif 154 #ifndef PPC_GET_DEXCR_ASPECT 155 # define PPC_GET_DEXCR_ASPECT(a, b) (-EINVAL) 156 #endif 157 #ifndef PPC_SET_DEXCR_ASPECT 158 # define PPC_SET_DEXCR_ASPECT(a, b, c) (-EINVAL) 159 #endif 160 161 /* 162 * this is where the system-wide overflow UID and GID are defined, for 163 * architectures that now have 32-bit UID/GID but didn't in the past 164 */ 165 166 int overflowuid = DEFAULT_OVERFLOWUID; 167 int overflowgid = DEFAULT_OVERFLOWGID; 168 169 EXPORT_SYMBOL(overflowuid); 170 EXPORT_SYMBOL(overflowgid); 171 172 /* 173 * the same as above, but for filesystems which can only store a 16-bit 174 * UID and GID. as such, this is needed on all architectures 175 */ 176 177 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 178 int fs_overflowgid = DEFAULT_FS_OVERFLOWGID; 179 180 EXPORT_SYMBOL(fs_overflowuid); 181 EXPORT_SYMBOL(fs_overflowgid); 182 183 static const struct ctl_table overflow_sysctl_table[] = { 184 { 185 .procname = "overflowuid", 186 .data = &overflowuid, 187 .maxlen = sizeof(int), 188 .mode = 0644, 189 .proc_handler = proc_dointvec_minmax, 190 .extra1 = SYSCTL_ZERO, 191 .extra2 = SYSCTL_MAXOLDUID, 192 }, 193 { 194 .procname = "overflowgid", 195 .data = &overflowgid, 196 .maxlen = sizeof(int), 197 .mode = 0644, 198 .proc_handler = proc_dointvec_minmax, 199 .extra1 = SYSCTL_ZERO, 200 .extra2 = SYSCTL_MAXOLDUID, 201 }, 202 }; 203 204 static int __init init_overflow_sysctl(void) 205 { 206 register_sysctl_init("kernel", overflow_sysctl_table); 207 return 0; 208 } 209 210 postcore_initcall(init_overflow_sysctl); 211 212 /* 213 * Returns true if current's euid is same as p's uid or euid, 214 * or has CAP_SYS_NICE to p's user_ns. 215 * 216 * Called with rcu_read_lock, creds are safe 217 */ 218 static bool set_one_prio_perm(struct task_struct *p) 219 { 220 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 221 222 if (uid_eq(pcred->uid, cred->euid) || 223 uid_eq(pcred->euid, cred->euid)) 224 return true; 225 if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) 226 return true; 227 return false; 228 } 229 230 /* 231 * set the priority of a task 232 * - the caller must hold the RCU read lock 233 */ 234 static int set_one_prio(struct task_struct *p, int niceval, int error) 235 { 236 int no_nice; 237 238 if (!set_one_prio_perm(p)) { 239 error = -EPERM; 240 goto out; 241 } 242 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 243 error = -EACCES; 244 goto out; 245 } 246 no_nice = security_task_setnice(p, niceval); 247 if (no_nice) { 248 error = no_nice; 249 goto out; 250 } 251 if (error == -ESRCH) 252 error = 0; 253 set_user_nice(p, niceval); 254 out: 255 return error; 256 } 257 258 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 259 { 260 struct task_struct *g, *p; 261 struct user_struct *user; 262 const struct cred *cred = current_cred(); 263 int error = -EINVAL; 264 struct pid *pgrp; 265 kuid_t uid; 266 267 if (which > PRIO_USER || which < PRIO_PROCESS) 268 goto out; 269 270 /* normalize: avoid signed division (rounding problems) */ 271 error = -ESRCH; 272 if (niceval < MIN_NICE) 273 niceval = MIN_NICE; 274 if (niceval > MAX_NICE) 275 niceval = MAX_NICE; 276 277 rcu_read_lock(); 278 switch (which) { 279 case PRIO_PROCESS: 280 if (who) 281 p = find_task_by_vpid(who); 282 else 283 p = current; 284 if (p) 285 error = set_one_prio(p, niceval, error); 286 break; 287 case PRIO_PGRP: 288 if (who) 289 pgrp = find_vpid(who); 290 else 291 pgrp = task_pgrp(current); 292 read_lock(&tasklist_lock); 293 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 294 error = set_one_prio(p, niceval, error); 295 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 296 read_unlock(&tasklist_lock); 297 break; 298 case PRIO_USER: 299 uid = make_kuid(cred->user_ns, who); 300 user = cred->user; 301 if (!who) 302 uid = cred->uid; 303 else if (!uid_eq(uid, cred->uid)) { 304 user = find_user(uid); 305 if (!user) 306 goto out_unlock; /* No processes for this user */ 307 } 308 for_each_process_thread(g, p) { 309 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) 310 error = set_one_prio(p, niceval, error); 311 } 312 if (!uid_eq(uid, cred->uid)) 313 free_uid(user); /* For find_user() */ 314 break; 315 } 316 out_unlock: 317 rcu_read_unlock(); 318 out: 319 return error; 320 } 321 322 /* 323 * Ugh. To avoid negative return values, "getpriority()" will 324 * not return the normal nice-value, but a negated value that 325 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 326 * to stay compatible. 327 */ 328 SYSCALL_DEFINE2(getpriority, int, which, int, who) 329 { 330 struct task_struct *g, *p; 331 struct user_struct *user; 332 const struct cred *cred = current_cred(); 333 long niceval, retval = -ESRCH; 334 struct pid *pgrp; 335 kuid_t uid; 336 337 if (which > PRIO_USER || which < PRIO_PROCESS) 338 return -EINVAL; 339 340 rcu_read_lock(); 341 switch (which) { 342 case PRIO_PROCESS: 343 if (who) 344 p = find_task_by_vpid(who); 345 else 346 p = current; 347 if (p) { 348 niceval = nice_to_rlimit(task_nice(p)); 349 if (niceval > retval) 350 retval = niceval; 351 } 352 break; 353 case PRIO_PGRP: 354 if (who) 355 pgrp = find_vpid(who); 356 else 357 pgrp = task_pgrp(current); 358 read_lock(&tasklist_lock); 359 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 360 niceval = nice_to_rlimit(task_nice(p)); 361 if (niceval > retval) 362 retval = niceval; 363 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 364 read_unlock(&tasklist_lock); 365 break; 366 case PRIO_USER: 367 uid = make_kuid(cred->user_ns, who); 368 user = cred->user; 369 if (!who) 370 uid = cred->uid; 371 else if (!uid_eq(uid, cred->uid)) { 372 user = find_user(uid); 373 if (!user) 374 goto out_unlock; /* No processes for this user */ 375 } 376 for_each_process_thread(g, p) { 377 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) { 378 niceval = nice_to_rlimit(task_nice(p)); 379 if (niceval > retval) 380 retval = niceval; 381 } 382 } 383 if (!uid_eq(uid, cred->uid)) 384 free_uid(user); /* for find_user() */ 385 break; 386 } 387 out_unlock: 388 rcu_read_unlock(); 389 390 return retval; 391 } 392 393 /* 394 * Unprivileged users may change the real gid to the effective gid 395 * or vice versa. (BSD-style) 396 * 397 * If you set the real gid at all, or set the effective gid to a value not 398 * equal to the real gid, then the saved gid is set to the new effective gid. 399 * 400 * This makes it possible for a setgid program to completely drop its 401 * privileges, which is often a useful assertion to make when you are doing 402 * a security audit over a program. 403 * 404 * The general idea is that a program which uses just setregid() will be 405 * 100% compatible with BSD. A program which uses just setgid() will be 406 * 100% compatible with POSIX with saved IDs. 407 * 408 * SMP: There are not races, the GIDs are checked only by filesystem 409 * operations (as far as semantic preservation is concerned). 410 */ 411 #ifdef CONFIG_MULTIUSER 412 long __sys_setregid(gid_t rgid, gid_t egid) 413 { 414 struct user_namespace *ns = current_user_ns(); 415 const struct cred *old; 416 struct cred *new; 417 int retval; 418 kgid_t krgid, kegid; 419 420 krgid = make_kgid(ns, rgid); 421 kegid = make_kgid(ns, egid); 422 423 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 424 return -EINVAL; 425 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 426 return -EINVAL; 427 428 new = prepare_creds(); 429 if (!new) 430 return -ENOMEM; 431 old = current_cred(); 432 433 retval = -EPERM; 434 if (rgid != (gid_t) -1) { 435 if (gid_eq(old->gid, krgid) || 436 gid_eq(old->egid, krgid) || 437 ns_capable_setid(old->user_ns, CAP_SETGID)) 438 new->gid = krgid; 439 else 440 goto error; 441 } 442 if (egid != (gid_t) -1) { 443 if (gid_eq(old->gid, kegid) || 444 gid_eq(old->egid, kegid) || 445 gid_eq(old->sgid, kegid) || 446 ns_capable_setid(old->user_ns, CAP_SETGID)) 447 new->egid = kegid; 448 else 449 goto error; 450 } 451 452 if (rgid != (gid_t) -1 || 453 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) 454 new->sgid = new->egid; 455 new->fsgid = new->egid; 456 457 retval = security_task_fix_setgid(new, old, LSM_SETID_RE); 458 if (retval < 0) 459 goto error; 460 461 return commit_creds(new); 462 463 error: 464 abort_creds(new); 465 return retval; 466 } 467 468 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 469 { 470 return __sys_setregid(rgid, egid); 471 } 472 473 /* 474 * setgid() is implemented like SysV w/ SAVED_IDS 475 * 476 * SMP: Same implicit races as above. 477 */ 478 long __sys_setgid(gid_t gid) 479 { 480 struct user_namespace *ns = current_user_ns(); 481 const struct cred *old; 482 struct cred *new; 483 int retval; 484 kgid_t kgid; 485 486 kgid = make_kgid(ns, gid); 487 if (!gid_valid(kgid)) 488 return -EINVAL; 489 490 new = prepare_creds(); 491 if (!new) 492 return -ENOMEM; 493 old = current_cred(); 494 495 retval = -EPERM; 496 if (ns_capable_setid(old->user_ns, CAP_SETGID)) 497 new->gid = new->egid = new->sgid = new->fsgid = kgid; 498 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) 499 new->egid = new->fsgid = kgid; 500 else 501 goto error; 502 503 retval = security_task_fix_setgid(new, old, LSM_SETID_ID); 504 if (retval < 0) 505 goto error; 506 507 return commit_creds(new); 508 509 error: 510 abort_creds(new); 511 return retval; 512 } 513 514 SYSCALL_DEFINE1(setgid, gid_t, gid) 515 { 516 return __sys_setgid(gid); 517 } 518 519 /* 520 * change the user struct in a credentials set to match the new UID 521 */ 522 static int set_user(struct cred *new) 523 { 524 struct user_struct *new_user; 525 526 new_user = alloc_uid(new->uid); 527 if (!new_user) 528 return -EAGAIN; 529 530 free_uid(new->user); 531 new->user = new_user; 532 return 0; 533 } 534 535 static void flag_nproc_exceeded(struct cred *new) 536 { 537 if (new->ucounts == current_ucounts()) 538 return; 539 540 /* 541 * We don't fail in case of NPROC limit excess here because too many 542 * poorly written programs don't check set*uid() return code, assuming 543 * it never fails if called by root. We may still enforce NPROC limit 544 * for programs doing set*uid()+execve() by harmlessly deferring the 545 * failure to the execve() stage. 546 */ 547 if (is_rlimit_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) && 548 new->user != INIT_USER) 549 current->flags |= PF_NPROC_EXCEEDED; 550 else 551 current->flags &= ~PF_NPROC_EXCEEDED; 552 } 553 554 /* 555 * Unprivileged users may change the real uid to the effective uid 556 * or vice versa. (BSD-style) 557 * 558 * If you set the real uid at all, or set the effective uid to a value not 559 * equal to the real uid, then the saved uid is set to the new effective uid. 560 * 561 * This makes it possible for a setuid program to completely drop its 562 * privileges, which is often a useful assertion to make when you are doing 563 * a security audit over a program. 564 * 565 * The general idea is that a program which uses just setreuid() will be 566 * 100% compatible with BSD. A program which uses just setuid() will be 567 * 100% compatible with POSIX with saved IDs. 568 */ 569 long __sys_setreuid(uid_t ruid, uid_t euid) 570 { 571 struct user_namespace *ns = current_user_ns(); 572 const struct cred *old; 573 struct cred *new; 574 int retval; 575 kuid_t kruid, keuid; 576 577 kruid = make_kuid(ns, ruid); 578 keuid = make_kuid(ns, euid); 579 580 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 581 return -EINVAL; 582 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 583 return -EINVAL; 584 585 new = prepare_creds(); 586 if (!new) 587 return -ENOMEM; 588 old = current_cred(); 589 590 retval = -EPERM; 591 if (ruid != (uid_t) -1) { 592 new->uid = kruid; 593 if (!uid_eq(old->uid, kruid) && 594 !uid_eq(old->euid, kruid) && 595 !ns_capable_setid(old->user_ns, CAP_SETUID)) 596 goto error; 597 } 598 599 if (euid != (uid_t) -1) { 600 new->euid = keuid; 601 if (!uid_eq(old->uid, keuid) && 602 !uid_eq(old->euid, keuid) && 603 !uid_eq(old->suid, keuid) && 604 !ns_capable_setid(old->user_ns, CAP_SETUID)) 605 goto error; 606 } 607 608 if (!uid_eq(new->uid, old->uid)) { 609 retval = set_user(new); 610 if (retval < 0) 611 goto error; 612 } 613 if (ruid != (uid_t) -1 || 614 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) 615 new->suid = new->euid; 616 new->fsuid = new->euid; 617 618 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 619 if (retval < 0) 620 goto error; 621 622 retval = set_cred_ucounts(new); 623 if (retval < 0) 624 goto error; 625 626 flag_nproc_exceeded(new); 627 return commit_creds(new); 628 629 error: 630 abort_creds(new); 631 return retval; 632 } 633 634 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 635 { 636 return __sys_setreuid(ruid, euid); 637 } 638 639 /* 640 * setuid() is implemented like SysV with SAVED_IDS 641 * 642 * Note that SAVED_ID's is deficient in that a setuid root program 643 * like sendmail, for example, cannot set its uid to be a normal 644 * user and then switch back, because if you're root, setuid() sets 645 * the saved uid too. If you don't like this, blame the bright people 646 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 647 * will allow a root program to temporarily drop privileges and be able to 648 * regain them by swapping the real and effective uid. 649 */ 650 long __sys_setuid(uid_t uid) 651 { 652 struct user_namespace *ns = current_user_ns(); 653 const struct cred *old; 654 struct cred *new; 655 int retval; 656 kuid_t kuid; 657 658 kuid = make_kuid(ns, uid); 659 if (!uid_valid(kuid)) 660 return -EINVAL; 661 662 new = prepare_creds(); 663 if (!new) 664 return -ENOMEM; 665 old = current_cred(); 666 667 retval = -EPERM; 668 if (ns_capable_setid(old->user_ns, CAP_SETUID)) { 669 new->suid = new->uid = kuid; 670 if (!uid_eq(kuid, old->uid)) { 671 retval = set_user(new); 672 if (retval < 0) 673 goto error; 674 } 675 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { 676 goto error; 677 } 678 679 new->fsuid = new->euid = kuid; 680 681 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 682 if (retval < 0) 683 goto error; 684 685 retval = set_cred_ucounts(new); 686 if (retval < 0) 687 goto error; 688 689 flag_nproc_exceeded(new); 690 return commit_creds(new); 691 692 error: 693 abort_creds(new); 694 return retval; 695 } 696 697 SYSCALL_DEFINE1(setuid, uid_t, uid) 698 { 699 return __sys_setuid(uid); 700 } 701 702 703 /* 704 * This function implements a generic ability to update ruid, euid, 705 * and suid. This allows you to implement the 4.4 compatible seteuid(). 706 */ 707 long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) 708 { 709 struct user_namespace *ns = current_user_ns(); 710 const struct cred *old; 711 struct cred *new; 712 int retval; 713 kuid_t kruid, keuid, ksuid; 714 bool ruid_new, euid_new, suid_new; 715 716 kruid = make_kuid(ns, ruid); 717 keuid = make_kuid(ns, euid); 718 ksuid = make_kuid(ns, suid); 719 720 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 721 return -EINVAL; 722 723 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 724 return -EINVAL; 725 726 if ((suid != (uid_t) -1) && !uid_valid(ksuid)) 727 return -EINVAL; 728 729 old = current_cred(); 730 731 /* check for no-op */ 732 if ((ruid == (uid_t) -1 || uid_eq(kruid, old->uid)) && 733 (euid == (uid_t) -1 || (uid_eq(keuid, old->euid) && 734 uid_eq(keuid, old->fsuid))) && 735 (suid == (uid_t) -1 || uid_eq(ksuid, old->suid))) 736 return 0; 737 738 ruid_new = ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && 739 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid); 740 euid_new = euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && 741 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid); 742 suid_new = suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && 743 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid); 744 if ((ruid_new || euid_new || suid_new) && 745 !ns_capable_setid(old->user_ns, CAP_SETUID)) 746 return -EPERM; 747 748 new = prepare_creds(); 749 if (!new) 750 return -ENOMEM; 751 752 if (ruid != (uid_t) -1) { 753 new->uid = kruid; 754 if (!uid_eq(kruid, old->uid)) { 755 retval = set_user(new); 756 if (retval < 0) 757 goto error; 758 } 759 } 760 if (euid != (uid_t) -1) 761 new->euid = keuid; 762 if (suid != (uid_t) -1) 763 new->suid = ksuid; 764 new->fsuid = new->euid; 765 766 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 767 if (retval < 0) 768 goto error; 769 770 retval = set_cred_ucounts(new); 771 if (retval < 0) 772 goto error; 773 774 flag_nproc_exceeded(new); 775 return commit_creds(new); 776 777 error: 778 abort_creds(new); 779 return retval; 780 } 781 782 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 783 { 784 return __sys_setresuid(ruid, euid, suid); 785 } 786 787 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) 788 { 789 const struct cred *cred = current_cred(); 790 int retval; 791 uid_t ruid, euid, suid; 792 793 ruid = from_kuid_munged(cred->user_ns, cred->uid); 794 euid = from_kuid_munged(cred->user_ns, cred->euid); 795 suid = from_kuid_munged(cred->user_ns, cred->suid); 796 797 retval = put_user(ruid, ruidp); 798 if (!retval) { 799 retval = put_user(euid, euidp); 800 if (!retval) 801 return put_user(suid, suidp); 802 } 803 return retval; 804 } 805 806 /* 807 * Same as above, but for rgid, egid, sgid. 808 */ 809 long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) 810 { 811 struct user_namespace *ns = current_user_ns(); 812 const struct cred *old; 813 struct cred *new; 814 int retval; 815 kgid_t krgid, kegid, ksgid; 816 bool rgid_new, egid_new, sgid_new; 817 818 krgid = make_kgid(ns, rgid); 819 kegid = make_kgid(ns, egid); 820 ksgid = make_kgid(ns, sgid); 821 822 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 823 return -EINVAL; 824 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 825 return -EINVAL; 826 if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) 827 return -EINVAL; 828 829 old = current_cred(); 830 831 /* check for no-op */ 832 if ((rgid == (gid_t) -1 || gid_eq(krgid, old->gid)) && 833 (egid == (gid_t) -1 || (gid_eq(kegid, old->egid) && 834 gid_eq(kegid, old->fsgid))) && 835 (sgid == (gid_t) -1 || gid_eq(ksgid, old->sgid))) 836 return 0; 837 838 rgid_new = rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && 839 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid); 840 egid_new = egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && 841 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid); 842 sgid_new = sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && 843 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid); 844 if ((rgid_new || egid_new || sgid_new) && 845 !ns_capable_setid(old->user_ns, CAP_SETGID)) 846 return -EPERM; 847 848 new = prepare_creds(); 849 if (!new) 850 return -ENOMEM; 851 852 if (rgid != (gid_t) -1) 853 new->gid = krgid; 854 if (egid != (gid_t) -1) 855 new->egid = kegid; 856 if (sgid != (gid_t) -1) 857 new->sgid = ksgid; 858 new->fsgid = new->egid; 859 860 retval = security_task_fix_setgid(new, old, LSM_SETID_RES); 861 if (retval < 0) 862 goto error; 863 864 return commit_creds(new); 865 866 error: 867 abort_creds(new); 868 return retval; 869 } 870 871 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 872 { 873 return __sys_setresgid(rgid, egid, sgid); 874 } 875 876 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) 877 { 878 const struct cred *cred = current_cred(); 879 int retval; 880 gid_t rgid, egid, sgid; 881 882 rgid = from_kgid_munged(cred->user_ns, cred->gid); 883 egid = from_kgid_munged(cred->user_ns, cred->egid); 884 sgid = from_kgid_munged(cred->user_ns, cred->sgid); 885 886 retval = put_user(rgid, rgidp); 887 if (!retval) { 888 retval = put_user(egid, egidp); 889 if (!retval) 890 retval = put_user(sgid, sgidp); 891 } 892 893 return retval; 894 } 895 896 897 /* 898 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 899 * is used for "access()" and for the NFS daemon (letting nfsd stay at 900 * whatever uid it wants to). It normally shadows "euid", except when 901 * explicitly set by setfsuid() or for access.. 902 */ 903 long __sys_setfsuid(uid_t uid) 904 { 905 const struct cred *old; 906 struct cred *new; 907 uid_t old_fsuid; 908 kuid_t kuid; 909 910 old = current_cred(); 911 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); 912 913 kuid = make_kuid(old->user_ns, uid); 914 if (!uid_valid(kuid)) 915 return old_fsuid; 916 917 new = prepare_creds(); 918 if (!new) 919 return old_fsuid; 920 921 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || 922 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || 923 ns_capable_setid(old->user_ns, CAP_SETUID)) { 924 if (!uid_eq(kuid, old->fsuid)) { 925 new->fsuid = kuid; 926 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 927 goto change_okay; 928 } 929 } 930 931 abort_creds(new); 932 return old_fsuid; 933 934 change_okay: 935 commit_creds(new); 936 return old_fsuid; 937 } 938 939 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 940 { 941 return __sys_setfsuid(uid); 942 } 943 944 /* 945 * Samma på svenska.. 946 */ 947 long __sys_setfsgid(gid_t gid) 948 { 949 const struct cred *old; 950 struct cred *new; 951 gid_t old_fsgid; 952 kgid_t kgid; 953 954 old = current_cred(); 955 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); 956 957 kgid = make_kgid(old->user_ns, gid); 958 if (!gid_valid(kgid)) 959 return old_fsgid; 960 961 new = prepare_creds(); 962 if (!new) 963 return old_fsgid; 964 965 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || 966 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || 967 ns_capable_setid(old->user_ns, CAP_SETGID)) { 968 if (!gid_eq(kgid, old->fsgid)) { 969 new->fsgid = kgid; 970 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0) 971 goto change_okay; 972 } 973 } 974 975 abort_creds(new); 976 return old_fsgid; 977 978 change_okay: 979 commit_creds(new); 980 return old_fsgid; 981 } 982 983 SYSCALL_DEFINE1(setfsgid, gid_t, gid) 984 { 985 return __sys_setfsgid(gid); 986 } 987 #endif /* CONFIG_MULTIUSER */ 988 989 /** 990 * sys_getpid - return the thread group id of the current process 991 * 992 * Note, despite the name, this returns the tgid not the pid. The tgid and 993 * the pid are identical unless CLONE_THREAD was specified on clone() in 994 * which case the tgid is the same in all threads of the same group. 995 * 996 * This is SMP safe as current->tgid does not change. 997 */ 998 SYSCALL_DEFINE0(getpid) 999 { 1000 return task_tgid_vnr(current); 1001 } 1002 1003 /* Thread ID - the internal kernel "pid" */ 1004 SYSCALL_DEFINE0(gettid) 1005 { 1006 return task_pid_vnr(current); 1007 } 1008 1009 /* 1010 * Accessing ->real_parent is not SMP-safe, it could 1011 * change from under us. However, we can use a stale 1012 * value of ->real_parent under rcu_read_lock(), see 1013 * release_task()->call_rcu(delayed_put_task_struct). 1014 */ 1015 SYSCALL_DEFINE0(getppid) 1016 { 1017 int pid; 1018 1019 rcu_read_lock(); 1020 pid = task_tgid_vnr(rcu_dereference(current->real_parent)); 1021 rcu_read_unlock(); 1022 1023 return pid; 1024 } 1025 1026 SYSCALL_DEFINE0(getuid) 1027 { 1028 /* Only we change this so SMP safe */ 1029 return from_kuid_munged(current_user_ns(), current_uid()); 1030 } 1031 1032 SYSCALL_DEFINE0(geteuid) 1033 { 1034 /* Only we change this so SMP safe */ 1035 return from_kuid_munged(current_user_ns(), current_euid()); 1036 } 1037 1038 SYSCALL_DEFINE0(getgid) 1039 { 1040 /* Only we change this so SMP safe */ 1041 return from_kgid_munged(current_user_ns(), current_gid()); 1042 } 1043 1044 SYSCALL_DEFINE0(getegid) 1045 { 1046 /* Only we change this so SMP safe */ 1047 return from_kgid_munged(current_user_ns(), current_egid()); 1048 } 1049 1050 static void do_sys_times(struct tms *tms) 1051 { 1052 u64 tgutime, tgstime, cutime, cstime; 1053 1054 thread_group_cputime_adjusted(current, &tgutime, &tgstime); 1055 cutime = current->signal->cutime; 1056 cstime = current->signal->cstime; 1057 tms->tms_utime = nsec_to_clock_t(tgutime); 1058 tms->tms_stime = nsec_to_clock_t(tgstime); 1059 tms->tms_cutime = nsec_to_clock_t(cutime); 1060 tms->tms_cstime = nsec_to_clock_t(cstime); 1061 } 1062 1063 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 1064 { 1065 if (tbuf) { 1066 struct tms tmp; 1067 1068 do_sys_times(&tmp); 1069 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 1070 return -EFAULT; 1071 } 1072 force_successful_syscall_return(); 1073 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 1074 } 1075 1076 #ifdef CONFIG_COMPAT 1077 static compat_clock_t clock_t_to_compat_clock_t(clock_t x) 1078 { 1079 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x)); 1080 } 1081 1082 COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf) 1083 { 1084 if (tbuf) { 1085 struct tms tms; 1086 struct compat_tms tmp; 1087 1088 do_sys_times(&tms); 1089 /* Convert our struct tms to the compat version. */ 1090 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime); 1091 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime); 1092 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime); 1093 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime); 1094 if (copy_to_user(tbuf, &tmp, sizeof(tmp))) 1095 return -EFAULT; 1096 } 1097 force_successful_syscall_return(); 1098 return compat_jiffies_to_clock_t(jiffies); 1099 } 1100 #endif 1101 1102 /* 1103 * This needs some heavy checking ... 1104 * I just haven't the stomach for it. I also don't fully 1105 * understand sessions/pgrp etc. Let somebody who does explain it. 1106 * 1107 * OK, I think I have the protection semantics right.... this is really 1108 * only important on a multi-user system anyway, to make sure one user 1109 * can't send a signal to a process owned by another. -TYT, 12/12/91 1110 * 1111 * !PF_FORKNOEXEC check to conform completely to POSIX. 1112 */ 1113 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 1114 { 1115 struct task_struct *p; 1116 struct task_struct *group_leader = current->group_leader; 1117 struct pid *pids[PIDTYPE_MAX] = { 0 }; 1118 struct pid *pgrp; 1119 int err; 1120 1121 if (!pid) 1122 pid = task_pid_vnr(group_leader); 1123 if (!pgid) 1124 pgid = pid; 1125 if (pgid < 0) 1126 return -EINVAL; 1127 rcu_read_lock(); 1128 1129 /* From this point forward we keep holding onto the tasklist lock 1130 * so that our parent does not change from under us. -DaveM 1131 */ 1132 write_lock_irq(&tasklist_lock); 1133 1134 err = -ESRCH; 1135 p = find_task_by_vpid(pid); 1136 if (!p) 1137 goto out; 1138 1139 err = -EINVAL; 1140 if (!thread_group_leader(p)) 1141 goto out; 1142 1143 if (same_thread_group(p->real_parent, group_leader)) { 1144 err = -EPERM; 1145 if (task_session(p) != task_session(group_leader)) 1146 goto out; 1147 err = -EACCES; 1148 if (!(p->flags & PF_FORKNOEXEC)) 1149 goto out; 1150 } else { 1151 err = -ESRCH; 1152 if (p != group_leader) 1153 goto out; 1154 } 1155 1156 err = -EPERM; 1157 if (p->signal->leader) 1158 goto out; 1159 1160 pgrp = task_pid(p); 1161 if (pgid != pid) { 1162 struct task_struct *g; 1163 1164 pgrp = find_vpid(pgid); 1165 g = pid_task(pgrp, PIDTYPE_PGID); 1166 if (!g || task_session(g) != task_session(group_leader)) 1167 goto out; 1168 } 1169 1170 err = security_task_setpgid(p, pgid); 1171 if (err) 1172 goto out; 1173 1174 if (task_pgrp(p) != pgrp) 1175 change_pid(pids, p, PIDTYPE_PGID, pgrp); 1176 1177 err = 0; 1178 out: 1179 /* All paths lead to here, thus we are safe. -DaveM */ 1180 write_unlock_irq(&tasklist_lock); 1181 rcu_read_unlock(); 1182 free_pids(pids); 1183 return err; 1184 } 1185 1186 static int do_getpgid(pid_t pid) 1187 { 1188 struct task_struct *p; 1189 struct pid *grp; 1190 int retval; 1191 1192 rcu_read_lock(); 1193 if (!pid) 1194 grp = task_pgrp(current); 1195 else { 1196 retval = -ESRCH; 1197 p = find_task_by_vpid(pid); 1198 if (!p) 1199 goto out; 1200 grp = task_pgrp(p); 1201 if (!grp) 1202 goto out; 1203 1204 retval = security_task_getpgid(p); 1205 if (retval) 1206 goto out; 1207 } 1208 retval = pid_vnr(grp); 1209 out: 1210 rcu_read_unlock(); 1211 return retval; 1212 } 1213 1214 SYSCALL_DEFINE1(getpgid, pid_t, pid) 1215 { 1216 return do_getpgid(pid); 1217 } 1218 1219 #ifdef __ARCH_WANT_SYS_GETPGRP 1220 1221 SYSCALL_DEFINE0(getpgrp) 1222 { 1223 return do_getpgid(0); 1224 } 1225 1226 #endif 1227 1228 SYSCALL_DEFINE1(getsid, pid_t, pid) 1229 { 1230 struct task_struct *p; 1231 struct pid *sid; 1232 int retval; 1233 1234 rcu_read_lock(); 1235 if (!pid) 1236 sid = task_session(current); 1237 else { 1238 retval = -ESRCH; 1239 p = find_task_by_vpid(pid); 1240 if (!p) 1241 goto out; 1242 sid = task_session(p); 1243 if (!sid) 1244 goto out; 1245 1246 retval = security_task_getsid(p); 1247 if (retval) 1248 goto out; 1249 } 1250 retval = pid_vnr(sid); 1251 out: 1252 rcu_read_unlock(); 1253 return retval; 1254 } 1255 1256 static void set_special_pids(struct pid **pids, struct pid *pid) 1257 { 1258 struct task_struct *curr = current->group_leader; 1259 1260 if (task_session(curr) != pid) 1261 change_pid(pids, curr, PIDTYPE_SID, pid); 1262 1263 if (task_pgrp(curr) != pid) 1264 change_pid(pids, curr, PIDTYPE_PGID, pid); 1265 } 1266 1267 int ksys_setsid(void) 1268 { 1269 struct task_struct *group_leader = current->group_leader; 1270 struct pid *sid = task_pid(group_leader); 1271 struct pid *pids[PIDTYPE_MAX] = { 0 }; 1272 pid_t session = pid_vnr(sid); 1273 int err = -EPERM; 1274 1275 write_lock_irq(&tasklist_lock); 1276 /* Fail if I am already a session leader */ 1277 if (group_leader->signal->leader) 1278 goto out; 1279 1280 /* Fail if a process group id already exists that equals the 1281 * proposed session id. 1282 */ 1283 if (pid_task(sid, PIDTYPE_PGID)) 1284 goto out; 1285 1286 group_leader->signal->leader = 1; 1287 set_special_pids(pids, sid); 1288 1289 proc_clear_tty(group_leader); 1290 1291 err = session; 1292 out: 1293 write_unlock_irq(&tasklist_lock); 1294 free_pids(pids); 1295 if (err > 0) { 1296 proc_sid_connector(group_leader); 1297 sched_autogroup_create_attach(group_leader); 1298 } 1299 return err; 1300 } 1301 1302 SYSCALL_DEFINE0(setsid) 1303 { 1304 return ksys_setsid(); 1305 } 1306 1307 DECLARE_RWSEM(uts_sem); 1308 1309 #ifdef COMPAT_UTS_MACHINE 1310 #define override_architecture(name) \ 1311 (personality(current->personality) == PER_LINUX32 && \ 1312 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ 1313 sizeof(COMPAT_UTS_MACHINE))) 1314 #else 1315 #define override_architecture(name) 0 1316 #endif 1317 1318 /* 1319 * Work around broken programs that cannot handle "Linux 3.0". 1320 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 1321 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be 1322 * 2.6.60. 1323 */ 1324 static int override_release(char __user *release, size_t len) 1325 { 1326 int ret = 0; 1327 1328 if (current->personality & UNAME26) { 1329 const char *rest = UTS_RELEASE; 1330 char buf[65] = { 0 }; 1331 int ndots = 0; 1332 unsigned v; 1333 size_t copy; 1334 1335 while (*rest) { 1336 if (*rest == '.' && ++ndots >= 3) 1337 break; 1338 if (!isdigit(*rest) && *rest != '.') 1339 break; 1340 rest++; 1341 } 1342 v = LINUX_VERSION_PATCHLEVEL + 60; 1343 copy = clamp_t(size_t, len, 1, sizeof(buf)); 1344 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); 1345 ret = copy_to_user(release, buf, copy + 1); 1346 } 1347 return ret; 1348 } 1349 1350 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1351 { 1352 struct new_utsname tmp; 1353 1354 down_read(&uts_sem); 1355 memcpy(&tmp, utsname(), sizeof(tmp)); 1356 up_read(&uts_sem); 1357 if (copy_to_user(name, &tmp, sizeof(tmp))) 1358 return -EFAULT; 1359 1360 if (override_release(name->release, sizeof(name->release))) 1361 return -EFAULT; 1362 if (override_architecture(name)) 1363 return -EFAULT; 1364 return 0; 1365 } 1366 1367 #ifdef __ARCH_WANT_SYS_OLD_UNAME 1368 /* 1369 * Old cruft 1370 */ 1371 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) 1372 { 1373 struct old_utsname tmp; 1374 1375 if (!name) 1376 return -EFAULT; 1377 1378 down_read(&uts_sem); 1379 memcpy(&tmp, utsname(), sizeof(tmp)); 1380 up_read(&uts_sem); 1381 if (copy_to_user(name, &tmp, sizeof(tmp))) 1382 return -EFAULT; 1383 1384 if (override_release(name->release, sizeof(name->release))) 1385 return -EFAULT; 1386 if (override_architecture(name)) 1387 return -EFAULT; 1388 return 0; 1389 } 1390 1391 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) 1392 { 1393 struct oldold_utsname tmp; 1394 1395 if (!name) 1396 return -EFAULT; 1397 1398 memset(&tmp, 0, sizeof(tmp)); 1399 1400 down_read(&uts_sem); 1401 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN); 1402 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN); 1403 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN); 1404 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN); 1405 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN); 1406 up_read(&uts_sem); 1407 if (copy_to_user(name, &tmp, sizeof(tmp))) 1408 return -EFAULT; 1409 1410 if (override_architecture(name)) 1411 return -EFAULT; 1412 if (override_release(name->release, sizeof(name->release))) 1413 return -EFAULT; 1414 return 0; 1415 } 1416 #endif 1417 1418 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1419 { 1420 int errno; 1421 char tmp[__NEW_UTS_LEN]; 1422 1423 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1424 return -EPERM; 1425 1426 if (len < 0 || len > __NEW_UTS_LEN) 1427 return -EINVAL; 1428 errno = -EFAULT; 1429 if (!copy_from_user(tmp, name, len)) { 1430 struct new_utsname *u; 1431 1432 add_device_randomness(tmp, len); 1433 down_write(&uts_sem); 1434 u = utsname(); 1435 memcpy(u->nodename, tmp, len); 1436 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1437 errno = 0; 1438 uts_proc_notify(UTS_PROC_HOSTNAME); 1439 up_write(&uts_sem); 1440 } 1441 return errno; 1442 } 1443 1444 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1445 1446 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1447 { 1448 int i; 1449 struct new_utsname *u; 1450 char tmp[__NEW_UTS_LEN + 1]; 1451 1452 if (len < 0) 1453 return -EINVAL; 1454 down_read(&uts_sem); 1455 u = utsname(); 1456 i = 1 + strlen(u->nodename); 1457 if (i > len) 1458 i = len; 1459 memcpy(tmp, u->nodename, i); 1460 up_read(&uts_sem); 1461 if (copy_to_user(name, tmp, i)) 1462 return -EFAULT; 1463 return 0; 1464 } 1465 1466 #endif 1467 1468 /* 1469 * Only setdomainname; getdomainname can be implemented by calling 1470 * uname() 1471 */ 1472 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1473 { 1474 int errno; 1475 char tmp[__NEW_UTS_LEN]; 1476 1477 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1478 return -EPERM; 1479 if (len < 0 || len > __NEW_UTS_LEN) 1480 return -EINVAL; 1481 1482 errno = -EFAULT; 1483 if (!copy_from_user(tmp, name, len)) { 1484 struct new_utsname *u; 1485 1486 add_device_randomness(tmp, len); 1487 down_write(&uts_sem); 1488 u = utsname(); 1489 memcpy(u->domainname, tmp, len); 1490 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1491 errno = 0; 1492 uts_proc_notify(UTS_PROC_DOMAINNAME); 1493 up_write(&uts_sem); 1494 } 1495 return errno; 1496 } 1497 1498 /* make sure you are allowed to change @tsk limits before calling this */ 1499 static int do_prlimit(struct task_struct *tsk, unsigned int resource, 1500 struct rlimit *new_rlim, struct rlimit *old_rlim) 1501 { 1502 struct rlimit *rlim; 1503 int retval = 0; 1504 1505 if (resource >= RLIM_NLIMITS) 1506 return -EINVAL; 1507 resource = array_index_nospec(resource, RLIM_NLIMITS); 1508 1509 if (new_rlim) { 1510 if (new_rlim->rlim_cur > new_rlim->rlim_max) 1511 return -EINVAL; 1512 if (resource == RLIMIT_NOFILE && 1513 new_rlim->rlim_max > sysctl_nr_open) 1514 return -EPERM; 1515 } 1516 1517 /* Holding a refcount on tsk protects tsk->signal from disappearing. */ 1518 rlim = tsk->signal->rlim + resource; 1519 task_lock(tsk->group_leader); 1520 if (new_rlim) { 1521 /* 1522 * Keep the capable check against init_user_ns until cgroups can 1523 * contain all limits. 1524 */ 1525 if (new_rlim->rlim_max > rlim->rlim_max && 1526 !capable(CAP_SYS_RESOURCE)) 1527 retval = -EPERM; 1528 if (!retval) 1529 retval = security_task_setrlimit(tsk, resource, new_rlim); 1530 } 1531 if (!retval) { 1532 if (old_rlim) 1533 *old_rlim = *rlim; 1534 if (new_rlim) 1535 *rlim = *new_rlim; 1536 } 1537 task_unlock(tsk->group_leader); 1538 1539 /* 1540 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not 1541 * infinite. In case of RLIM_INFINITY the posix CPU timer code 1542 * ignores the rlimit. 1543 */ 1544 if (!retval && new_rlim && resource == RLIMIT_CPU && 1545 new_rlim->rlim_cur != RLIM_INFINITY && 1546 IS_ENABLED(CONFIG_POSIX_TIMERS)) { 1547 /* 1548 * update_rlimit_cpu can fail if the task is exiting, but there 1549 * may be other tasks in the thread group that are not exiting, 1550 * and they need their cpu timers adjusted. 1551 * 1552 * The group_leader is the last task to be released, so if we 1553 * cannot update_rlimit_cpu on it, then the entire process is 1554 * exiting and we do not need to update at all. 1555 */ 1556 update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur); 1557 } 1558 1559 return retval; 1560 } 1561 1562 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1563 { 1564 struct rlimit value; 1565 int ret; 1566 1567 ret = do_prlimit(current, resource, NULL, &value); 1568 if (!ret) 1569 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1570 1571 return ret; 1572 } 1573 1574 #ifdef CONFIG_COMPAT 1575 1576 COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource, 1577 struct compat_rlimit __user *, rlim) 1578 { 1579 struct rlimit r; 1580 struct compat_rlimit r32; 1581 1582 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit))) 1583 return -EFAULT; 1584 1585 if (r32.rlim_cur == COMPAT_RLIM_INFINITY) 1586 r.rlim_cur = RLIM_INFINITY; 1587 else 1588 r.rlim_cur = r32.rlim_cur; 1589 if (r32.rlim_max == COMPAT_RLIM_INFINITY) 1590 r.rlim_max = RLIM_INFINITY; 1591 else 1592 r.rlim_max = r32.rlim_max; 1593 return do_prlimit(current, resource, &r, NULL); 1594 } 1595 1596 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource, 1597 struct compat_rlimit __user *, rlim) 1598 { 1599 struct rlimit r; 1600 int ret; 1601 1602 ret = do_prlimit(current, resource, NULL, &r); 1603 if (!ret) { 1604 struct compat_rlimit r32; 1605 if (r.rlim_cur > COMPAT_RLIM_INFINITY) 1606 r32.rlim_cur = COMPAT_RLIM_INFINITY; 1607 else 1608 r32.rlim_cur = r.rlim_cur; 1609 if (r.rlim_max > COMPAT_RLIM_INFINITY) 1610 r32.rlim_max = COMPAT_RLIM_INFINITY; 1611 else 1612 r32.rlim_max = r.rlim_max; 1613 1614 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit))) 1615 return -EFAULT; 1616 } 1617 return ret; 1618 } 1619 1620 #endif 1621 1622 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1623 1624 /* 1625 * Back compatibility for getrlimit. Needed for some apps. 1626 */ 1627 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1628 struct rlimit __user *, rlim) 1629 { 1630 struct rlimit x; 1631 if (resource >= RLIM_NLIMITS) 1632 return -EINVAL; 1633 1634 resource = array_index_nospec(resource, RLIM_NLIMITS); 1635 task_lock(current->group_leader); 1636 x = current->signal->rlim[resource]; 1637 task_unlock(current->group_leader); 1638 if (x.rlim_cur > 0x7FFFFFFF) 1639 x.rlim_cur = 0x7FFFFFFF; 1640 if (x.rlim_max > 0x7FFFFFFF) 1641 x.rlim_max = 0x7FFFFFFF; 1642 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0; 1643 } 1644 1645 #ifdef CONFIG_COMPAT 1646 COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1647 struct compat_rlimit __user *, rlim) 1648 { 1649 struct rlimit r; 1650 1651 if (resource >= RLIM_NLIMITS) 1652 return -EINVAL; 1653 1654 resource = array_index_nospec(resource, RLIM_NLIMITS); 1655 task_lock(current->group_leader); 1656 r = current->signal->rlim[resource]; 1657 task_unlock(current->group_leader); 1658 if (r.rlim_cur > 0x7FFFFFFF) 1659 r.rlim_cur = 0x7FFFFFFF; 1660 if (r.rlim_max > 0x7FFFFFFF) 1661 r.rlim_max = 0x7FFFFFFF; 1662 1663 if (put_user(r.rlim_cur, &rlim->rlim_cur) || 1664 put_user(r.rlim_max, &rlim->rlim_max)) 1665 return -EFAULT; 1666 return 0; 1667 } 1668 #endif 1669 1670 #endif 1671 1672 static inline bool rlim64_is_infinity(__u64 rlim64) 1673 { 1674 #if BITS_PER_LONG < 64 1675 return rlim64 >= ULONG_MAX; 1676 #else 1677 return rlim64 == RLIM64_INFINITY; 1678 #endif 1679 } 1680 1681 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) 1682 { 1683 if (rlim->rlim_cur == RLIM_INFINITY) 1684 rlim64->rlim_cur = RLIM64_INFINITY; 1685 else 1686 rlim64->rlim_cur = rlim->rlim_cur; 1687 if (rlim->rlim_max == RLIM_INFINITY) 1688 rlim64->rlim_max = RLIM64_INFINITY; 1689 else 1690 rlim64->rlim_max = rlim->rlim_max; 1691 } 1692 1693 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) 1694 { 1695 if (rlim64_is_infinity(rlim64->rlim_cur)) 1696 rlim->rlim_cur = RLIM_INFINITY; 1697 else 1698 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; 1699 if (rlim64_is_infinity(rlim64->rlim_max)) 1700 rlim->rlim_max = RLIM_INFINITY; 1701 else 1702 rlim->rlim_max = (unsigned long)rlim64->rlim_max; 1703 } 1704 1705 /* rcu lock must be held */ 1706 static int check_prlimit_permission(struct task_struct *task, 1707 unsigned int flags) 1708 { 1709 const struct cred *cred = current_cred(), *tcred; 1710 bool id_match; 1711 1712 if (current == task) 1713 return 0; 1714 1715 tcred = __task_cred(task); 1716 id_match = (uid_eq(cred->uid, tcred->euid) && 1717 uid_eq(cred->uid, tcred->suid) && 1718 uid_eq(cred->uid, tcred->uid) && 1719 gid_eq(cred->gid, tcred->egid) && 1720 gid_eq(cred->gid, tcred->sgid) && 1721 gid_eq(cred->gid, tcred->gid)); 1722 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) 1723 return -EPERM; 1724 1725 return security_task_prlimit(cred, tcred, flags); 1726 } 1727 1728 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, 1729 const struct rlimit64 __user *, new_rlim, 1730 struct rlimit64 __user *, old_rlim) 1731 { 1732 struct rlimit64 old64, new64; 1733 struct rlimit old, new; 1734 struct task_struct *tsk; 1735 unsigned int checkflags = 0; 1736 bool need_tasklist; 1737 int ret; 1738 1739 if (old_rlim) 1740 checkflags |= LSM_PRLIMIT_READ; 1741 1742 if (new_rlim) { 1743 if (copy_from_user(&new64, new_rlim, sizeof(new64))) 1744 return -EFAULT; 1745 rlim64_to_rlim(&new64, &new); 1746 checkflags |= LSM_PRLIMIT_WRITE; 1747 } 1748 1749 rcu_read_lock(); 1750 tsk = pid ? find_task_by_vpid(pid) : current; 1751 if (!tsk) { 1752 rcu_read_unlock(); 1753 return -ESRCH; 1754 } 1755 ret = check_prlimit_permission(tsk, checkflags); 1756 if (ret) { 1757 rcu_read_unlock(); 1758 return ret; 1759 } 1760 get_task_struct(tsk); 1761 rcu_read_unlock(); 1762 1763 need_tasklist = !same_thread_group(tsk, current); 1764 if (need_tasklist) { 1765 /* 1766 * Ensure we can't race with group exit or de_thread(), 1767 * so tsk->group_leader can't be freed or changed until 1768 * read_unlock(tasklist_lock) below. 1769 */ 1770 read_lock(&tasklist_lock); 1771 if (!pid_alive(tsk)) 1772 ret = -ESRCH; 1773 } 1774 1775 if (!ret) { 1776 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, 1777 old_rlim ? &old : NULL); 1778 } 1779 1780 if (need_tasklist) 1781 read_unlock(&tasklist_lock); 1782 1783 if (!ret && old_rlim) { 1784 rlim_to_rlim64(&old, &old64); 1785 if (copy_to_user(old_rlim, &old64, sizeof(old64))) 1786 ret = -EFAULT; 1787 } 1788 1789 put_task_struct(tsk); 1790 return ret; 1791 } 1792 1793 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1794 { 1795 struct rlimit new_rlim; 1796 1797 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1798 return -EFAULT; 1799 return do_prlimit(current, resource, &new_rlim, NULL); 1800 } 1801 1802 /* 1803 * It would make sense to put struct rusage in the task_struct, 1804 * except that would make the task_struct be *really big*. After 1805 * task_struct gets moved into malloc'ed memory, it would 1806 * make sense to do this. It will make moving the rest of the information 1807 * a lot simpler! (Which we're not doing right now because we're not 1808 * measuring them yet). 1809 * 1810 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1811 * races with threads incrementing their own counters. But since word 1812 * reads are atomic, we either get new values or old values and we don't 1813 * care which for the sums. We always take the siglock to protect reading 1814 * the c* fields from p->signal from races with exit.c updating those 1815 * fields when reaping, so a sample either gets all the additions of a 1816 * given child after it's reaped, or none so this sample is before reaping. 1817 * 1818 * Locking: 1819 * We need to take the siglock for CHILDEREN, SELF and BOTH 1820 * for the cases current multithreaded, non-current single threaded 1821 * non-current multithreaded. Thread traversal is now safe with 1822 * the siglock held. 1823 * Strictly speaking, we donot need to take the siglock if we are current and 1824 * single threaded, as no one else can take our signal_struct away, no one 1825 * else can reap the children to update signal->c* counters, and no one else 1826 * can race with the signal-> fields. If we do not take any lock, the 1827 * signal-> fields could be read out of order while another thread was just 1828 * exiting. So we should place a read memory barrier when we avoid the lock. 1829 * On the writer side, write memory barrier is implied in __exit_signal 1830 * as __exit_signal releases the siglock spinlock after updating the signal-> 1831 * fields. But we don't do this yet to keep things simple. 1832 * 1833 */ 1834 1835 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1836 { 1837 r->ru_nvcsw += t->nvcsw; 1838 r->ru_nivcsw += t->nivcsw; 1839 r->ru_minflt += t->min_flt; 1840 r->ru_majflt += t->maj_flt; 1841 r->ru_inblock += task_io_get_inblock(t); 1842 r->ru_oublock += task_io_get_oublock(t); 1843 } 1844 1845 void getrusage(struct task_struct *p, int who, struct rusage *r) 1846 { 1847 struct task_struct *t; 1848 unsigned long flags; 1849 u64 tgutime, tgstime, utime, stime; 1850 unsigned long maxrss; 1851 struct mm_struct *mm; 1852 struct signal_struct *sig = p->signal; 1853 unsigned int seq = 0; 1854 1855 retry: 1856 memset(r, 0, sizeof(*r)); 1857 utime = stime = 0; 1858 maxrss = 0; 1859 1860 if (who == RUSAGE_THREAD) { 1861 task_cputime_adjusted(current, &utime, &stime); 1862 accumulate_thread_rusage(p, r); 1863 maxrss = sig->maxrss; 1864 goto out_thread; 1865 } 1866 1867 flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq); 1868 1869 switch (who) { 1870 case RUSAGE_BOTH: 1871 case RUSAGE_CHILDREN: 1872 utime = sig->cutime; 1873 stime = sig->cstime; 1874 r->ru_nvcsw = sig->cnvcsw; 1875 r->ru_nivcsw = sig->cnivcsw; 1876 r->ru_minflt = sig->cmin_flt; 1877 r->ru_majflt = sig->cmaj_flt; 1878 r->ru_inblock = sig->cinblock; 1879 r->ru_oublock = sig->coublock; 1880 maxrss = sig->cmaxrss; 1881 1882 if (who == RUSAGE_CHILDREN) 1883 break; 1884 fallthrough; 1885 1886 case RUSAGE_SELF: 1887 r->ru_nvcsw += sig->nvcsw; 1888 r->ru_nivcsw += sig->nivcsw; 1889 r->ru_minflt += sig->min_flt; 1890 r->ru_majflt += sig->maj_flt; 1891 r->ru_inblock += sig->inblock; 1892 r->ru_oublock += sig->oublock; 1893 if (maxrss < sig->maxrss) 1894 maxrss = sig->maxrss; 1895 1896 rcu_read_lock(); 1897 __for_each_thread(sig, t) 1898 accumulate_thread_rusage(t, r); 1899 rcu_read_unlock(); 1900 1901 break; 1902 1903 default: 1904 BUG(); 1905 } 1906 1907 if (need_seqretry(&sig->stats_lock, seq)) { 1908 seq = 1; 1909 goto retry; 1910 } 1911 done_seqretry_irqrestore(&sig->stats_lock, seq, flags); 1912 1913 if (who == RUSAGE_CHILDREN) 1914 goto out_children; 1915 1916 thread_group_cputime_adjusted(p, &tgutime, &tgstime); 1917 utime += tgutime; 1918 stime += tgstime; 1919 1920 out_thread: 1921 mm = get_task_mm(p); 1922 if (mm) { 1923 setmax_mm_hiwater_rss(&maxrss, mm); 1924 mmput(mm); 1925 } 1926 1927 out_children: 1928 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1929 r->ru_utime = ns_to_kernel_old_timeval(utime); 1930 r->ru_stime = ns_to_kernel_old_timeval(stime); 1931 } 1932 1933 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1934 { 1935 struct rusage r; 1936 1937 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1938 who != RUSAGE_THREAD) 1939 return -EINVAL; 1940 1941 getrusage(current, who, &r); 1942 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1943 } 1944 1945 #ifdef CONFIG_COMPAT 1946 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) 1947 { 1948 struct rusage r; 1949 1950 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1951 who != RUSAGE_THREAD) 1952 return -EINVAL; 1953 1954 getrusage(current, who, &r); 1955 return put_compat_rusage(&r, ru); 1956 } 1957 #endif 1958 1959 SYSCALL_DEFINE1(umask, int, mask) 1960 { 1961 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1962 return mask; 1963 } 1964 1965 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) 1966 { 1967 CLASS(fd, exe)(fd); 1968 struct inode *inode; 1969 int err; 1970 1971 if (fd_empty(exe)) 1972 return -EBADF; 1973 1974 inode = file_inode(fd_file(exe)); 1975 1976 /* 1977 * Because the original mm->exe_file points to executable file, make 1978 * sure that this one is executable as well, to avoid breaking an 1979 * overall picture. 1980 */ 1981 if (!S_ISREG(inode->i_mode) || path_noexec(&fd_file(exe)->f_path)) 1982 return -EACCES; 1983 1984 err = file_permission(fd_file(exe), MAY_EXEC); 1985 if (err) 1986 return err; 1987 1988 return replace_mm_exe_file(mm, fd_file(exe)); 1989 } 1990 1991 /* 1992 * Check arithmetic relations of passed addresses. 1993 * 1994 * WARNING: we don't require any capability here so be very careful 1995 * in what is allowed for modification from userspace. 1996 */ 1997 static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map) 1998 { 1999 unsigned long mmap_max_addr = TASK_SIZE; 2000 int error = -EINVAL, i; 2001 2002 static const unsigned char offsets[] = { 2003 offsetof(struct prctl_mm_map, start_code), 2004 offsetof(struct prctl_mm_map, end_code), 2005 offsetof(struct prctl_mm_map, start_data), 2006 offsetof(struct prctl_mm_map, end_data), 2007 offsetof(struct prctl_mm_map, start_brk), 2008 offsetof(struct prctl_mm_map, brk), 2009 offsetof(struct prctl_mm_map, start_stack), 2010 offsetof(struct prctl_mm_map, arg_start), 2011 offsetof(struct prctl_mm_map, arg_end), 2012 offsetof(struct prctl_mm_map, env_start), 2013 offsetof(struct prctl_mm_map, env_end), 2014 }; 2015 2016 /* 2017 * Make sure the members are not somewhere outside 2018 * of allowed address space. 2019 */ 2020 for (i = 0; i < ARRAY_SIZE(offsets); i++) { 2021 u64 val = *(u64 *)((char *)prctl_map + offsets[i]); 2022 2023 if ((unsigned long)val >= mmap_max_addr || 2024 (unsigned long)val < mmap_min_addr) 2025 goto out; 2026 } 2027 2028 /* 2029 * Make sure the pairs are ordered. 2030 */ 2031 #define __prctl_check_order(__m1, __op, __m2) \ 2032 ((unsigned long)prctl_map->__m1 __op \ 2033 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL 2034 error = __prctl_check_order(start_code, <, end_code); 2035 error |= __prctl_check_order(start_data,<=, end_data); 2036 error |= __prctl_check_order(start_brk, <=, brk); 2037 error |= __prctl_check_order(arg_start, <=, arg_end); 2038 error |= __prctl_check_order(env_start, <=, env_end); 2039 if (error) 2040 goto out; 2041 #undef __prctl_check_order 2042 2043 error = -EINVAL; 2044 2045 /* 2046 * Neither we should allow to override limits if they set. 2047 */ 2048 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, 2049 prctl_map->start_brk, prctl_map->end_data, 2050 prctl_map->start_data)) 2051 goto out; 2052 2053 error = 0; 2054 out: 2055 return error; 2056 } 2057 2058 #ifdef CONFIG_CHECKPOINT_RESTORE 2059 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) 2060 { 2061 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; 2062 unsigned long user_auxv[AT_VECTOR_SIZE]; 2063 struct mm_struct *mm = current->mm; 2064 int error; 2065 2066 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 2067 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256); 2068 2069 if (opt == PR_SET_MM_MAP_SIZE) 2070 return put_user((unsigned int)sizeof(prctl_map), 2071 (unsigned int __user *)addr); 2072 2073 if (data_size != sizeof(prctl_map)) 2074 return -EINVAL; 2075 2076 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) 2077 return -EFAULT; 2078 2079 error = validate_prctl_map_addr(&prctl_map); 2080 if (error) 2081 return error; 2082 2083 if (prctl_map.auxv_size) { 2084 /* 2085 * Someone is trying to cheat the auxv vector. 2086 */ 2087 if (!prctl_map.auxv || 2088 prctl_map.auxv_size > sizeof(mm->saved_auxv)) 2089 return -EINVAL; 2090 2091 memset(user_auxv, 0, sizeof(user_auxv)); 2092 if (copy_from_user(user_auxv, 2093 (const void __user *)prctl_map.auxv, 2094 prctl_map.auxv_size)) 2095 return -EFAULT; 2096 2097 /* Last entry must be AT_NULL as specification requires */ 2098 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL; 2099 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL; 2100 } 2101 2102 if (prctl_map.exe_fd != (u32)-1) { 2103 /* 2104 * Check if the current user is checkpoint/restore capable. 2105 * At the time of this writing, it checks for CAP_SYS_ADMIN 2106 * or CAP_CHECKPOINT_RESTORE. 2107 * Note that a user with access to ptrace can masquerade an 2108 * arbitrary program as any executable, even setuid ones. 2109 * This may have implications in the tomoyo subsystem. 2110 */ 2111 if (!checkpoint_restore_ns_capable(current_user_ns())) 2112 return -EPERM; 2113 2114 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd); 2115 if (error) 2116 return error; 2117 } 2118 2119 /* 2120 * arg_lock protects concurrent updates but we still need mmap_lock for 2121 * read to exclude races with sys_brk. 2122 */ 2123 mmap_read_lock(mm); 2124 2125 /* 2126 * We don't validate if these members are pointing to 2127 * real present VMAs because application may have correspond 2128 * VMAs already unmapped and kernel uses these members for statistics 2129 * output in procfs mostly, except 2130 * 2131 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups 2132 * for VMAs when updating these members so anything wrong written 2133 * here cause kernel to swear at userspace program but won't lead 2134 * to any problem in kernel itself 2135 */ 2136 2137 spin_lock(&mm->arg_lock); 2138 mm->start_code = prctl_map.start_code; 2139 mm->end_code = prctl_map.end_code; 2140 mm->start_data = prctl_map.start_data; 2141 mm->end_data = prctl_map.end_data; 2142 mm->start_brk = prctl_map.start_brk; 2143 mm->brk = prctl_map.brk; 2144 mm->start_stack = prctl_map.start_stack; 2145 mm->arg_start = prctl_map.arg_start; 2146 mm->arg_end = prctl_map.arg_end; 2147 mm->env_start = prctl_map.env_start; 2148 mm->env_end = prctl_map.env_end; 2149 spin_unlock(&mm->arg_lock); 2150 2151 /* 2152 * Note this update of @saved_auxv is lockless thus 2153 * if someone reads this member in procfs while we're 2154 * updating -- it may get partly updated results. It's 2155 * known and acceptable trade off: we leave it as is to 2156 * not introduce additional locks here making the kernel 2157 * more complex. 2158 */ 2159 if (prctl_map.auxv_size) 2160 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); 2161 2162 mmap_read_unlock(mm); 2163 return 0; 2164 } 2165 #endif /* CONFIG_CHECKPOINT_RESTORE */ 2166 2167 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr, 2168 unsigned long len) 2169 { 2170 /* 2171 * This doesn't move the auxiliary vector itself since it's pinned to 2172 * mm_struct, but it permits filling the vector with new values. It's 2173 * up to the caller to provide sane values here, otherwise userspace 2174 * tools which use this vector might be unhappy. 2175 */ 2176 unsigned long user_auxv[AT_VECTOR_SIZE] = {}; 2177 2178 if (len > sizeof(user_auxv)) 2179 return -EINVAL; 2180 2181 if (copy_from_user(user_auxv, (const void __user *)addr, len)) 2182 return -EFAULT; 2183 2184 /* Make sure the last entry is always AT_NULL */ 2185 user_auxv[AT_VECTOR_SIZE - 2] = 0; 2186 user_auxv[AT_VECTOR_SIZE - 1] = 0; 2187 2188 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 2189 2190 task_lock(current); 2191 memcpy(mm->saved_auxv, user_auxv, len); 2192 task_unlock(current); 2193 2194 return 0; 2195 } 2196 2197 static int prctl_set_mm(int opt, unsigned long addr, 2198 unsigned long arg4, unsigned long arg5) 2199 { 2200 struct mm_struct *mm = current->mm; 2201 struct prctl_mm_map prctl_map = { 2202 .auxv = NULL, 2203 .auxv_size = 0, 2204 .exe_fd = -1, 2205 }; 2206 struct vm_area_struct *vma; 2207 int error; 2208 2209 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV && 2210 opt != PR_SET_MM_MAP && 2211 opt != PR_SET_MM_MAP_SIZE))) 2212 return -EINVAL; 2213 2214 #ifdef CONFIG_CHECKPOINT_RESTORE 2215 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE) 2216 return prctl_set_mm_map(opt, (const void __user *)addr, arg4); 2217 #endif 2218 2219 if (!capable(CAP_SYS_RESOURCE)) 2220 return -EPERM; 2221 2222 if (opt == PR_SET_MM_EXE_FILE) 2223 return prctl_set_mm_exe_file(mm, (unsigned int)addr); 2224 2225 if (opt == PR_SET_MM_AUXV) 2226 return prctl_set_auxv(mm, addr, arg4); 2227 2228 if (addr >= TASK_SIZE || addr < mmap_min_addr) 2229 return -EINVAL; 2230 2231 error = -EINVAL; 2232 2233 /* 2234 * arg_lock protects concurrent updates of arg boundaries, we need 2235 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr 2236 * validation. 2237 */ 2238 mmap_read_lock(mm); 2239 vma = find_vma(mm, addr); 2240 2241 spin_lock(&mm->arg_lock); 2242 prctl_map.start_code = mm->start_code; 2243 prctl_map.end_code = mm->end_code; 2244 prctl_map.start_data = mm->start_data; 2245 prctl_map.end_data = mm->end_data; 2246 prctl_map.start_brk = mm->start_brk; 2247 prctl_map.brk = mm->brk; 2248 prctl_map.start_stack = mm->start_stack; 2249 prctl_map.arg_start = mm->arg_start; 2250 prctl_map.arg_end = mm->arg_end; 2251 prctl_map.env_start = mm->env_start; 2252 prctl_map.env_end = mm->env_end; 2253 2254 switch (opt) { 2255 case PR_SET_MM_START_CODE: 2256 prctl_map.start_code = addr; 2257 break; 2258 case PR_SET_MM_END_CODE: 2259 prctl_map.end_code = addr; 2260 break; 2261 case PR_SET_MM_START_DATA: 2262 prctl_map.start_data = addr; 2263 break; 2264 case PR_SET_MM_END_DATA: 2265 prctl_map.end_data = addr; 2266 break; 2267 case PR_SET_MM_START_STACK: 2268 prctl_map.start_stack = addr; 2269 break; 2270 case PR_SET_MM_START_BRK: 2271 prctl_map.start_brk = addr; 2272 break; 2273 case PR_SET_MM_BRK: 2274 prctl_map.brk = addr; 2275 break; 2276 case PR_SET_MM_ARG_START: 2277 prctl_map.arg_start = addr; 2278 break; 2279 case PR_SET_MM_ARG_END: 2280 prctl_map.arg_end = addr; 2281 break; 2282 case PR_SET_MM_ENV_START: 2283 prctl_map.env_start = addr; 2284 break; 2285 case PR_SET_MM_ENV_END: 2286 prctl_map.env_end = addr; 2287 break; 2288 default: 2289 goto out; 2290 } 2291 2292 error = validate_prctl_map_addr(&prctl_map); 2293 if (error) 2294 goto out; 2295 2296 switch (opt) { 2297 /* 2298 * If command line arguments and environment 2299 * are placed somewhere else on stack, we can 2300 * set them up here, ARG_START/END to setup 2301 * command line arguments and ENV_START/END 2302 * for environment. 2303 */ 2304 case PR_SET_MM_START_STACK: 2305 case PR_SET_MM_ARG_START: 2306 case PR_SET_MM_ARG_END: 2307 case PR_SET_MM_ENV_START: 2308 case PR_SET_MM_ENV_END: 2309 if (!vma) { 2310 error = -EFAULT; 2311 goto out; 2312 } 2313 } 2314 2315 mm->start_code = prctl_map.start_code; 2316 mm->end_code = prctl_map.end_code; 2317 mm->start_data = prctl_map.start_data; 2318 mm->end_data = prctl_map.end_data; 2319 mm->start_brk = prctl_map.start_brk; 2320 mm->brk = prctl_map.brk; 2321 mm->start_stack = prctl_map.start_stack; 2322 mm->arg_start = prctl_map.arg_start; 2323 mm->arg_end = prctl_map.arg_end; 2324 mm->env_start = prctl_map.env_start; 2325 mm->env_end = prctl_map.env_end; 2326 2327 error = 0; 2328 out: 2329 spin_unlock(&mm->arg_lock); 2330 mmap_read_unlock(mm); 2331 return error; 2332 } 2333 2334 #ifdef CONFIG_CHECKPOINT_RESTORE 2335 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr) 2336 { 2337 return put_user(me->clear_child_tid, tid_addr); 2338 } 2339 #else 2340 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr) 2341 { 2342 return -EINVAL; 2343 } 2344 #endif 2345 2346 static int propagate_has_child_subreaper(struct task_struct *p, void *data) 2347 { 2348 /* 2349 * If task has has_child_subreaper - all its descendants 2350 * already have these flag too and new descendants will 2351 * inherit it on fork, skip them. 2352 * 2353 * If we've found child_reaper - skip descendants in 2354 * it's subtree as they will never get out pidns. 2355 */ 2356 if (p->signal->has_child_subreaper || 2357 is_child_reaper(task_pid(p))) 2358 return 0; 2359 2360 p->signal->has_child_subreaper = 1; 2361 return 1; 2362 } 2363 2364 int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which) 2365 { 2366 return -EINVAL; 2367 } 2368 2369 int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which, 2370 unsigned long ctrl) 2371 { 2372 return -EINVAL; 2373 } 2374 2375 int __weak arch_get_shadow_stack_status(struct task_struct *t, unsigned long __user *status) 2376 { 2377 return -EINVAL; 2378 } 2379 2380 int __weak arch_set_shadow_stack_status(struct task_struct *t, unsigned long status) 2381 { 2382 return -EINVAL; 2383 } 2384 2385 int __weak arch_lock_shadow_stack_status(struct task_struct *t, unsigned long status) 2386 { 2387 return -EINVAL; 2388 } 2389 2390 #define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE) 2391 2392 static int prctl_set_vma(unsigned long opt, unsigned long addr, 2393 unsigned long size, unsigned long arg) 2394 { 2395 int error; 2396 2397 switch (opt) { 2398 case PR_SET_VMA_ANON_NAME: 2399 error = set_anon_vma_name(addr, size, (const char __user *)arg); 2400 break; 2401 default: 2402 error = -EINVAL; 2403 } 2404 2405 return error; 2406 } 2407 2408 static inline unsigned long get_current_mdwe(void) 2409 { 2410 unsigned long ret = 0; 2411 2412 if (mm_flags_test(MMF_HAS_MDWE, current->mm)) 2413 ret |= PR_MDWE_REFUSE_EXEC_GAIN; 2414 if (mm_flags_test(MMF_HAS_MDWE_NO_INHERIT, current->mm)) 2415 ret |= PR_MDWE_NO_INHERIT; 2416 2417 return ret; 2418 } 2419 2420 static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3, 2421 unsigned long arg4, unsigned long arg5) 2422 { 2423 unsigned long current_bits; 2424 2425 if (arg3 || arg4 || arg5) 2426 return -EINVAL; 2427 2428 if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT)) 2429 return -EINVAL; 2430 2431 /* NO_INHERIT only makes sense with REFUSE_EXEC_GAIN */ 2432 if (bits & PR_MDWE_NO_INHERIT && !(bits & PR_MDWE_REFUSE_EXEC_GAIN)) 2433 return -EINVAL; 2434 2435 /* 2436 * EOPNOTSUPP might be more appropriate here in principle, but 2437 * existing userspace depends on EINVAL specifically. 2438 */ 2439 if (!arch_memory_deny_write_exec_supported()) 2440 return -EINVAL; 2441 2442 current_bits = get_current_mdwe(); 2443 if (current_bits && current_bits != bits) 2444 return -EPERM; /* Cannot unset the flags */ 2445 2446 if (bits & PR_MDWE_NO_INHERIT) 2447 mm_flags_set(MMF_HAS_MDWE_NO_INHERIT, current->mm); 2448 if (bits & PR_MDWE_REFUSE_EXEC_GAIN) 2449 mm_flags_set(MMF_HAS_MDWE, current->mm); 2450 2451 return 0; 2452 } 2453 2454 static inline int prctl_get_mdwe(unsigned long arg2, unsigned long arg3, 2455 unsigned long arg4, unsigned long arg5) 2456 { 2457 if (arg2 || arg3 || arg4 || arg5) 2458 return -EINVAL; 2459 return get_current_mdwe(); 2460 } 2461 2462 static int prctl_get_auxv(void __user *addr, unsigned long len) 2463 { 2464 struct mm_struct *mm = current->mm; 2465 unsigned long size = min_t(unsigned long, sizeof(mm->saved_auxv), len); 2466 2467 if (size && copy_to_user(addr, mm->saved_auxv, size)) 2468 return -EFAULT; 2469 return sizeof(mm->saved_auxv); 2470 } 2471 2472 static int prctl_get_thp_disable(unsigned long arg2, unsigned long arg3, 2473 unsigned long arg4, unsigned long arg5) 2474 { 2475 struct mm_struct *mm = current->mm; 2476 2477 if (arg2 || arg3 || arg4 || arg5) 2478 return -EINVAL; 2479 2480 /* If disabled, we return "1 | flags", otherwise 0. */ 2481 if (mm_flags_test(MMF_DISABLE_THP_COMPLETELY, mm)) 2482 return 1; 2483 else if (mm_flags_test(MMF_DISABLE_THP_EXCEPT_ADVISED, mm)) 2484 return 1 | PR_THP_DISABLE_EXCEPT_ADVISED; 2485 return 0; 2486 } 2487 2488 static int prctl_set_thp_disable(bool thp_disable, unsigned long flags, 2489 unsigned long arg4, unsigned long arg5) 2490 { 2491 struct mm_struct *mm = current->mm; 2492 2493 if (arg4 || arg5) 2494 return -EINVAL; 2495 2496 /* Flags are only allowed when disabling. */ 2497 if ((!thp_disable && flags) || (flags & ~PR_THP_DISABLE_EXCEPT_ADVISED)) 2498 return -EINVAL; 2499 if (mmap_write_lock_killable(current->mm)) 2500 return -EINTR; 2501 if (thp_disable) { 2502 if (flags & PR_THP_DISABLE_EXCEPT_ADVISED) { 2503 mm_flags_clear(MMF_DISABLE_THP_COMPLETELY, mm); 2504 mm_flags_set(MMF_DISABLE_THP_EXCEPT_ADVISED, mm); 2505 } else { 2506 mm_flags_set(MMF_DISABLE_THP_COMPLETELY, mm); 2507 mm_flags_clear(MMF_DISABLE_THP_EXCEPT_ADVISED, mm); 2508 } 2509 } else { 2510 mm_flags_clear(MMF_DISABLE_THP_COMPLETELY, mm); 2511 mm_flags_clear(MMF_DISABLE_THP_EXCEPT_ADVISED, mm); 2512 } 2513 mmap_write_unlock(current->mm); 2514 return 0; 2515 } 2516 2517 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 2518 unsigned long, arg4, unsigned long, arg5) 2519 { 2520 struct task_struct *me = current; 2521 unsigned char comm[sizeof(me->comm)]; 2522 long error; 2523 2524 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 2525 if (error != -ENOSYS) 2526 return error; 2527 2528 error = 0; 2529 switch (option) { 2530 case PR_SET_PDEATHSIG: 2531 if (!valid_signal(arg2)) { 2532 error = -EINVAL; 2533 break; 2534 } 2535 /* 2536 * Ensure that either: 2537 * 2538 * 1. Subsequent getppid() calls reflect the parent process having died. 2539 * 2. forget_original_parent() will send the new me->pdeath_signal. 2540 * 2541 * Also prevent the read of me->pdeath_signal from being a data race. 2542 */ 2543 read_lock(&tasklist_lock); 2544 me->pdeath_signal = arg2; 2545 read_unlock(&tasklist_lock); 2546 break; 2547 case PR_GET_PDEATHSIG: 2548 error = put_user(me->pdeath_signal, (int __user *)arg2); 2549 break; 2550 case PR_GET_DUMPABLE: 2551 error = get_dumpable(me->mm); 2552 break; 2553 case PR_SET_DUMPABLE: 2554 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { 2555 error = -EINVAL; 2556 break; 2557 } 2558 set_dumpable(me->mm, arg2); 2559 break; 2560 2561 case PR_SET_UNALIGN: 2562 error = SET_UNALIGN_CTL(me, arg2); 2563 break; 2564 case PR_GET_UNALIGN: 2565 error = GET_UNALIGN_CTL(me, arg2); 2566 break; 2567 case PR_SET_FPEMU: 2568 error = SET_FPEMU_CTL(me, arg2); 2569 break; 2570 case PR_GET_FPEMU: 2571 error = GET_FPEMU_CTL(me, arg2); 2572 break; 2573 case PR_SET_FPEXC: 2574 error = SET_FPEXC_CTL(me, arg2); 2575 break; 2576 case PR_GET_FPEXC: 2577 error = GET_FPEXC_CTL(me, arg2); 2578 break; 2579 case PR_GET_TIMING: 2580 error = PR_TIMING_STATISTICAL; 2581 break; 2582 case PR_SET_TIMING: 2583 if (arg2 != PR_TIMING_STATISTICAL) 2584 error = -EINVAL; 2585 break; 2586 case PR_SET_NAME: 2587 comm[sizeof(me->comm) - 1] = 0; 2588 if (strncpy_from_user(comm, (char __user *)arg2, 2589 sizeof(me->comm) - 1) < 0) 2590 return -EFAULT; 2591 set_task_comm(me, comm); 2592 proc_comm_connector(me); 2593 break; 2594 case PR_GET_NAME: 2595 get_task_comm(comm, me); 2596 if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) 2597 return -EFAULT; 2598 break; 2599 case PR_GET_ENDIAN: 2600 error = GET_ENDIAN(me, arg2); 2601 break; 2602 case PR_SET_ENDIAN: 2603 error = SET_ENDIAN(me, arg2); 2604 break; 2605 case PR_GET_SECCOMP: 2606 error = prctl_get_seccomp(); 2607 break; 2608 case PR_SET_SECCOMP: 2609 error = prctl_set_seccomp(arg2, (char __user *)arg3); 2610 break; 2611 case PR_GET_TSC: 2612 error = GET_TSC_CTL(arg2); 2613 break; 2614 case PR_SET_TSC: 2615 error = SET_TSC_CTL(arg2); 2616 break; 2617 case PR_TASK_PERF_EVENTS_DISABLE: 2618 error = perf_event_task_disable(); 2619 break; 2620 case PR_TASK_PERF_EVENTS_ENABLE: 2621 error = perf_event_task_enable(); 2622 break; 2623 case PR_GET_TIMERSLACK: 2624 if (current->timer_slack_ns > ULONG_MAX) 2625 error = ULONG_MAX; 2626 else 2627 error = current->timer_slack_ns; 2628 break; 2629 case PR_SET_TIMERSLACK: 2630 if (rt_or_dl_task_policy(current)) 2631 break; 2632 if (arg2 <= 0) 2633 current->timer_slack_ns = 2634 current->default_timer_slack_ns; 2635 else 2636 current->timer_slack_ns = arg2; 2637 break; 2638 case PR_MCE_KILL: 2639 if (arg4 | arg5) 2640 return -EINVAL; 2641 switch (arg2) { 2642 case PR_MCE_KILL_CLEAR: 2643 if (arg3 != 0) 2644 return -EINVAL; 2645 current->flags &= ~PF_MCE_PROCESS; 2646 break; 2647 case PR_MCE_KILL_SET: 2648 current->flags |= PF_MCE_PROCESS; 2649 if (arg3 == PR_MCE_KILL_EARLY) 2650 current->flags |= PF_MCE_EARLY; 2651 else if (arg3 == PR_MCE_KILL_LATE) 2652 current->flags &= ~PF_MCE_EARLY; 2653 else if (arg3 == PR_MCE_KILL_DEFAULT) 2654 current->flags &= 2655 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 2656 else 2657 return -EINVAL; 2658 break; 2659 default: 2660 return -EINVAL; 2661 } 2662 break; 2663 case PR_MCE_KILL_GET: 2664 if (arg2 | arg3 | arg4 | arg5) 2665 return -EINVAL; 2666 if (current->flags & PF_MCE_PROCESS) 2667 error = (current->flags & PF_MCE_EARLY) ? 2668 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 2669 else 2670 error = PR_MCE_KILL_DEFAULT; 2671 break; 2672 case PR_SET_MM: 2673 error = prctl_set_mm(arg2, arg3, arg4, arg5); 2674 break; 2675 case PR_GET_TID_ADDRESS: 2676 error = prctl_get_tid_address(me, (int __user * __user *)arg2); 2677 break; 2678 case PR_SET_CHILD_SUBREAPER: 2679 me->signal->is_child_subreaper = !!arg2; 2680 if (!arg2) 2681 break; 2682 2683 walk_process_tree(me, propagate_has_child_subreaper, NULL); 2684 break; 2685 case PR_GET_CHILD_SUBREAPER: 2686 error = put_user(me->signal->is_child_subreaper, 2687 (int __user *)arg2); 2688 break; 2689 case PR_SET_NO_NEW_PRIVS: 2690 if (arg2 != 1 || arg3 || arg4 || arg5) 2691 return -EINVAL; 2692 2693 task_set_no_new_privs(current); 2694 break; 2695 case PR_GET_NO_NEW_PRIVS: 2696 if (arg2 || arg3 || arg4 || arg5) 2697 return -EINVAL; 2698 return task_no_new_privs(current) ? 1 : 0; 2699 case PR_GET_THP_DISABLE: 2700 error = prctl_get_thp_disable(arg2, arg3, arg4, arg5); 2701 break; 2702 case PR_SET_THP_DISABLE: 2703 error = prctl_set_thp_disable(arg2, arg3, arg4, arg5); 2704 break; 2705 case PR_MPX_ENABLE_MANAGEMENT: 2706 case PR_MPX_DISABLE_MANAGEMENT: 2707 /* No longer implemented: */ 2708 return -EINVAL; 2709 case PR_SET_FP_MODE: 2710 error = SET_FP_MODE(me, arg2); 2711 break; 2712 case PR_GET_FP_MODE: 2713 error = GET_FP_MODE(me); 2714 break; 2715 case PR_SVE_SET_VL: 2716 error = SVE_SET_VL(arg2); 2717 break; 2718 case PR_SVE_GET_VL: 2719 error = SVE_GET_VL(); 2720 break; 2721 case PR_SME_SET_VL: 2722 error = SME_SET_VL(arg2); 2723 break; 2724 case PR_SME_GET_VL: 2725 error = SME_GET_VL(); 2726 break; 2727 case PR_GET_SPECULATION_CTRL: 2728 if (arg3 || arg4 || arg5) 2729 return -EINVAL; 2730 error = arch_prctl_spec_ctrl_get(me, arg2); 2731 break; 2732 case PR_SET_SPECULATION_CTRL: 2733 if (arg4 || arg5) 2734 return -EINVAL; 2735 error = arch_prctl_spec_ctrl_set(me, arg2, arg3); 2736 break; 2737 case PR_PAC_RESET_KEYS: 2738 if (arg3 || arg4 || arg5) 2739 return -EINVAL; 2740 error = PAC_RESET_KEYS(me, arg2); 2741 break; 2742 case PR_PAC_SET_ENABLED_KEYS: 2743 if (arg4 || arg5) 2744 return -EINVAL; 2745 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3); 2746 break; 2747 case PR_PAC_GET_ENABLED_KEYS: 2748 if (arg2 || arg3 || arg4 || arg5) 2749 return -EINVAL; 2750 error = PAC_GET_ENABLED_KEYS(me); 2751 break; 2752 case PR_SET_TAGGED_ADDR_CTRL: 2753 if (arg3 || arg4 || arg5) 2754 return -EINVAL; 2755 error = SET_TAGGED_ADDR_CTRL(arg2); 2756 break; 2757 case PR_GET_TAGGED_ADDR_CTRL: 2758 if (arg2 || arg3 || arg4 || arg5) 2759 return -EINVAL; 2760 error = GET_TAGGED_ADDR_CTRL(); 2761 break; 2762 case PR_SET_IO_FLUSHER: 2763 if (!capable(CAP_SYS_RESOURCE)) 2764 return -EPERM; 2765 2766 if (arg3 || arg4 || arg5) 2767 return -EINVAL; 2768 2769 if (arg2 == 1) 2770 current->flags |= PR_IO_FLUSHER; 2771 else if (!arg2) 2772 current->flags &= ~PR_IO_FLUSHER; 2773 else 2774 return -EINVAL; 2775 break; 2776 case PR_GET_IO_FLUSHER: 2777 if (!capable(CAP_SYS_RESOURCE)) 2778 return -EPERM; 2779 2780 if (arg2 || arg3 || arg4 || arg5) 2781 return -EINVAL; 2782 2783 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER; 2784 break; 2785 case PR_SET_SYSCALL_USER_DISPATCH: 2786 error = set_syscall_user_dispatch(arg2, arg3, arg4, 2787 (char __user *) arg5); 2788 break; 2789 #ifdef CONFIG_SCHED_CORE 2790 case PR_SCHED_CORE: 2791 error = sched_core_share_pid(arg2, arg3, arg4, arg5); 2792 break; 2793 #endif 2794 case PR_SET_MDWE: 2795 error = prctl_set_mdwe(arg2, arg3, arg4, arg5); 2796 break; 2797 case PR_GET_MDWE: 2798 error = prctl_get_mdwe(arg2, arg3, arg4, arg5); 2799 break; 2800 case PR_PPC_GET_DEXCR: 2801 if (arg3 || arg4 || arg5) 2802 return -EINVAL; 2803 error = PPC_GET_DEXCR_ASPECT(me, arg2); 2804 break; 2805 case PR_PPC_SET_DEXCR: 2806 if (arg4 || arg5) 2807 return -EINVAL; 2808 error = PPC_SET_DEXCR_ASPECT(me, arg2, arg3); 2809 break; 2810 case PR_SET_VMA: 2811 error = prctl_set_vma(arg2, arg3, arg4, arg5); 2812 break; 2813 case PR_GET_AUXV: 2814 if (arg4 || arg5) 2815 return -EINVAL; 2816 error = prctl_get_auxv((void __user *)arg2, arg3); 2817 break; 2818 #ifdef CONFIG_KSM 2819 case PR_SET_MEMORY_MERGE: 2820 if (arg3 || arg4 || arg5) 2821 return -EINVAL; 2822 if (mmap_write_lock_killable(me->mm)) 2823 return -EINTR; 2824 2825 if (arg2) 2826 error = ksm_enable_merge_any(me->mm); 2827 else 2828 error = ksm_disable_merge_any(me->mm); 2829 mmap_write_unlock(me->mm); 2830 break; 2831 case PR_GET_MEMORY_MERGE: 2832 if (arg2 || arg3 || arg4 || arg5) 2833 return -EINVAL; 2834 2835 error = !!mm_flags_test(MMF_VM_MERGE_ANY, me->mm); 2836 break; 2837 #endif 2838 case PR_RISCV_V_SET_CONTROL: 2839 error = RISCV_V_SET_CONTROL(arg2); 2840 break; 2841 case PR_RISCV_V_GET_CONTROL: 2842 error = RISCV_V_GET_CONTROL(); 2843 break; 2844 case PR_RISCV_SET_ICACHE_FLUSH_CTX: 2845 error = RISCV_SET_ICACHE_FLUSH_CTX(arg2, arg3); 2846 break; 2847 case PR_GET_SHADOW_STACK_STATUS: 2848 if (arg3 || arg4 || arg5) 2849 return -EINVAL; 2850 error = arch_get_shadow_stack_status(me, (unsigned long __user *) arg2); 2851 break; 2852 case PR_SET_SHADOW_STACK_STATUS: 2853 if (arg3 || arg4 || arg5) 2854 return -EINVAL; 2855 error = arch_set_shadow_stack_status(me, arg2); 2856 break; 2857 case PR_LOCK_SHADOW_STACK_STATUS: 2858 if (arg3 || arg4 || arg5) 2859 return -EINVAL; 2860 error = arch_lock_shadow_stack_status(me, arg2); 2861 break; 2862 case PR_TIMER_CREATE_RESTORE_IDS: 2863 if (arg3 || arg4 || arg5) 2864 return -EINVAL; 2865 error = posixtimer_create_prctl(arg2); 2866 break; 2867 case PR_FUTEX_HASH: 2868 error = futex_hash_prctl(arg2, arg3, arg4); 2869 break; 2870 default: 2871 trace_task_prctl_unknown(option, arg2, arg3, arg4, arg5); 2872 error = -EINVAL; 2873 break; 2874 } 2875 return error; 2876 } 2877 2878 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, void __user *, unused) 2879 { 2880 int err = 0; 2881 int cpu = raw_smp_processor_id(); 2882 2883 if (cpup) 2884 err |= put_user(cpu, cpup); 2885 if (nodep) 2886 err |= put_user(cpu_to_node(cpu), nodep); 2887 return err ? -EFAULT : 0; 2888 } 2889 2890 /** 2891 * do_sysinfo - fill in sysinfo struct 2892 * @info: pointer to buffer to fill 2893 */ 2894 static int do_sysinfo(struct sysinfo *info) 2895 { 2896 unsigned long mem_total, sav_total; 2897 unsigned int mem_unit, bitcount; 2898 struct timespec64 tp; 2899 2900 memset(info, 0, sizeof(struct sysinfo)); 2901 2902 ktime_get_boottime_ts64(&tp); 2903 timens_add_boottime(&tp); 2904 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); 2905 2906 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); 2907 2908 info->procs = nr_threads; 2909 2910 si_meminfo(info); 2911 si_swapinfo(info); 2912 2913 /* 2914 * If the sum of all the available memory (i.e. ram + swap) 2915 * is less than can be stored in a 32 bit unsigned long then 2916 * we can be binary compatible with 2.2.x kernels. If not, 2917 * well, in that case 2.2.x was broken anyways... 2918 * 2919 * -Erik Andersen <andersee@debian.org> 2920 */ 2921 2922 mem_total = info->totalram + info->totalswap; 2923 if (mem_total < info->totalram || mem_total < info->totalswap) 2924 goto out; 2925 bitcount = 0; 2926 mem_unit = info->mem_unit; 2927 while (mem_unit > 1) { 2928 bitcount++; 2929 mem_unit >>= 1; 2930 sav_total = mem_total; 2931 mem_total <<= 1; 2932 if (mem_total < sav_total) 2933 goto out; 2934 } 2935 2936 /* 2937 * If mem_total did not overflow, multiply all memory values by 2938 * info->mem_unit and set it to 1. This leaves things compatible 2939 * with 2.2.x, and also retains compatibility with earlier 2.4.x 2940 * kernels... 2941 */ 2942 2943 info->mem_unit = 1; 2944 info->totalram <<= bitcount; 2945 info->freeram <<= bitcount; 2946 info->sharedram <<= bitcount; 2947 info->bufferram <<= bitcount; 2948 info->totalswap <<= bitcount; 2949 info->freeswap <<= bitcount; 2950 info->totalhigh <<= bitcount; 2951 info->freehigh <<= bitcount; 2952 2953 out: 2954 return 0; 2955 } 2956 2957 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) 2958 { 2959 struct sysinfo val; 2960 2961 do_sysinfo(&val); 2962 2963 if (copy_to_user(info, &val, sizeof(struct sysinfo))) 2964 return -EFAULT; 2965 2966 return 0; 2967 } 2968 2969 #ifdef CONFIG_COMPAT 2970 struct compat_sysinfo { 2971 s32 uptime; 2972 u32 loads[3]; 2973 u32 totalram; 2974 u32 freeram; 2975 u32 sharedram; 2976 u32 bufferram; 2977 u32 totalswap; 2978 u32 freeswap; 2979 u16 procs; 2980 u16 pad; 2981 u32 totalhigh; 2982 u32 freehigh; 2983 u32 mem_unit; 2984 char _f[20-2*sizeof(u32)-sizeof(int)]; 2985 }; 2986 2987 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) 2988 { 2989 struct sysinfo s; 2990 struct compat_sysinfo s_32; 2991 2992 do_sysinfo(&s); 2993 2994 /* Check to see if any memory value is too large for 32-bit and scale 2995 * down if needed 2996 */ 2997 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) { 2998 int bitcount = 0; 2999 3000 while (s.mem_unit < PAGE_SIZE) { 3001 s.mem_unit <<= 1; 3002 bitcount++; 3003 } 3004 3005 s.totalram >>= bitcount; 3006 s.freeram >>= bitcount; 3007 s.sharedram >>= bitcount; 3008 s.bufferram >>= bitcount; 3009 s.totalswap >>= bitcount; 3010 s.freeswap >>= bitcount; 3011 s.totalhigh >>= bitcount; 3012 s.freehigh >>= bitcount; 3013 } 3014 3015 memset(&s_32, 0, sizeof(s_32)); 3016 s_32.uptime = s.uptime; 3017 s_32.loads[0] = s.loads[0]; 3018 s_32.loads[1] = s.loads[1]; 3019 s_32.loads[2] = s.loads[2]; 3020 s_32.totalram = s.totalram; 3021 s_32.freeram = s.freeram; 3022 s_32.sharedram = s.sharedram; 3023 s_32.bufferram = s.bufferram; 3024 s_32.totalswap = s.totalswap; 3025 s_32.freeswap = s.freeswap; 3026 s_32.procs = s.procs; 3027 s_32.totalhigh = s.totalhigh; 3028 s_32.freehigh = s.freehigh; 3029 s_32.mem_unit = s.mem_unit; 3030 if (copy_to_user(info, &s_32, sizeof(s_32))) 3031 return -EFAULT; 3032 return 0; 3033 } 3034 #endif /* CONFIG_COMPAT */ 3035