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/perf_event.h> 19 #include <linux/resource.h> 20 #include <linux/kernel.h> 21 #include <linux/workqueue.h> 22 #include <linux/capability.h> 23 #include <linux/device.h> 24 #include <linux/key.h> 25 #include <linux/times.h> 26 #include <linux/posix-timers.h> 27 #include <linux/security.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 #include <linux/syscall_user_dispatch.h> 46 47 #include <linux/compat.h> 48 #include <linux/syscalls.h> 49 #include <linux/kprobes.h> 50 #include <linux/user_namespace.h> 51 #include <linux/time_namespace.h> 52 #include <linux/binfmts.h> 53 54 #include <linux/sched.h> 55 #include <linux/sched/autogroup.h> 56 #include <linux/sched/loadavg.h> 57 #include <linux/sched/stat.h> 58 #include <linux/sched/mm.h> 59 #include <linux/sched/coredump.h> 60 #include <linux/sched/task.h> 61 #include <linux/sched/cputime.h> 62 #include <linux/rcupdate.h> 63 #include <linux/uidgid.h> 64 #include <linux/cred.h> 65 66 #include <linux/nospec.h> 67 68 #include <linux/kmsg_dump.h> 69 /* Move somewhere else to avoid recompiling? */ 70 #include <generated/utsrelease.h> 71 72 #include <linux/uaccess.h> 73 #include <asm/io.h> 74 #include <asm/unistd.h> 75 76 #include "uid16.h" 77 78 #ifndef SET_UNALIGN_CTL 79 # define SET_UNALIGN_CTL(a, b) (-EINVAL) 80 #endif 81 #ifndef GET_UNALIGN_CTL 82 # define GET_UNALIGN_CTL(a, b) (-EINVAL) 83 #endif 84 #ifndef SET_FPEMU_CTL 85 # define SET_FPEMU_CTL(a, b) (-EINVAL) 86 #endif 87 #ifndef GET_FPEMU_CTL 88 # define GET_FPEMU_CTL(a, b) (-EINVAL) 89 #endif 90 #ifndef SET_FPEXC_CTL 91 # define SET_FPEXC_CTL(a, b) (-EINVAL) 92 #endif 93 #ifndef GET_FPEXC_CTL 94 # define GET_FPEXC_CTL(a, b) (-EINVAL) 95 #endif 96 #ifndef GET_ENDIAN 97 # define GET_ENDIAN(a, b) (-EINVAL) 98 #endif 99 #ifndef SET_ENDIAN 100 # define SET_ENDIAN(a, b) (-EINVAL) 101 #endif 102 #ifndef GET_TSC_CTL 103 # define GET_TSC_CTL(a) (-EINVAL) 104 #endif 105 #ifndef SET_TSC_CTL 106 # define SET_TSC_CTL(a) (-EINVAL) 107 #endif 108 #ifndef GET_FP_MODE 109 # define GET_FP_MODE(a) (-EINVAL) 110 #endif 111 #ifndef SET_FP_MODE 112 # define SET_FP_MODE(a,b) (-EINVAL) 113 #endif 114 #ifndef SVE_SET_VL 115 # define SVE_SET_VL(a) (-EINVAL) 116 #endif 117 #ifndef SVE_GET_VL 118 # define SVE_GET_VL() (-EINVAL) 119 #endif 120 #ifndef PAC_RESET_KEYS 121 # define PAC_RESET_KEYS(a, b) (-EINVAL) 122 #endif 123 #ifndef PAC_SET_ENABLED_KEYS 124 # define PAC_SET_ENABLED_KEYS(a, b, c) (-EINVAL) 125 #endif 126 #ifndef PAC_GET_ENABLED_KEYS 127 # define PAC_GET_ENABLED_KEYS(a) (-EINVAL) 128 #endif 129 #ifndef SET_TAGGED_ADDR_CTRL 130 # define SET_TAGGED_ADDR_CTRL(a) (-EINVAL) 131 #endif 132 #ifndef GET_TAGGED_ADDR_CTRL 133 # define GET_TAGGED_ADDR_CTRL() (-EINVAL) 134 #endif 135 136 /* 137 * this is where the system-wide overflow UID and GID are defined, for 138 * architectures that now have 32-bit UID/GID but didn't in the past 139 */ 140 141 int overflowuid = DEFAULT_OVERFLOWUID; 142 int overflowgid = DEFAULT_OVERFLOWGID; 143 144 EXPORT_SYMBOL(overflowuid); 145 EXPORT_SYMBOL(overflowgid); 146 147 /* 148 * the same as above, but for filesystems which can only store a 16-bit 149 * UID and GID. as such, this is needed on all architectures 150 */ 151 152 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; 153 int fs_overflowgid = DEFAULT_FS_OVERFLOWGID; 154 155 EXPORT_SYMBOL(fs_overflowuid); 156 EXPORT_SYMBOL(fs_overflowgid); 157 158 /* 159 * Returns true if current's euid is same as p's uid or euid, 160 * or has CAP_SYS_NICE to p's user_ns. 161 * 162 * Called with rcu_read_lock, creds are safe 163 */ 164 static bool set_one_prio_perm(struct task_struct *p) 165 { 166 const struct cred *cred = current_cred(), *pcred = __task_cred(p); 167 168 if (uid_eq(pcred->uid, cred->euid) || 169 uid_eq(pcred->euid, cred->euid)) 170 return true; 171 if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) 172 return true; 173 return false; 174 } 175 176 /* 177 * set the priority of a task 178 * - the caller must hold the RCU read lock 179 */ 180 static int set_one_prio(struct task_struct *p, int niceval, int error) 181 { 182 int no_nice; 183 184 if (!set_one_prio_perm(p)) { 185 error = -EPERM; 186 goto out; 187 } 188 if (niceval < task_nice(p) && !can_nice(p, niceval)) { 189 error = -EACCES; 190 goto out; 191 } 192 no_nice = security_task_setnice(p, niceval); 193 if (no_nice) { 194 error = no_nice; 195 goto out; 196 } 197 if (error == -ESRCH) 198 error = 0; 199 set_user_nice(p, niceval); 200 out: 201 return error; 202 } 203 204 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) 205 { 206 struct task_struct *g, *p; 207 struct user_struct *user; 208 const struct cred *cred = current_cred(); 209 int error = -EINVAL; 210 struct pid *pgrp; 211 kuid_t uid; 212 213 if (which > PRIO_USER || which < PRIO_PROCESS) 214 goto out; 215 216 /* normalize: avoid signed division (rounding problems) */ 217 error = -ESRCH; 218 if (niceval < MIN_NICE) 219 niceval = MIN_NICE; 220 if (niceval > MAX_NICE) 221 niceval = MAX_NICE; 222 223 rcu_read_lock(); 224 switch (which) { 225 case PRIO_PROCESS: 226 if (who) 227 p = find_task_by_vpid(who); 228 else 229 p = current; 230 if (p) 231 error = set_one_prio(p, niceval, error); 232 break; 233 case PRIO_PGRP: 234 if (who) 235 pgrp = find_vpid(who); 236 else 237 pgrp = task_pgrp(current); 238 read_lock(&tasklist_lock); 239 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 240 error = set_one_prio(p, niceval, error); 241 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 242 read_unlock(&tasklist_lock); 243 break; 244 case PRIO_USER: 245 uid = make_kuid(cred->user_ns, who); 246 user = cred->user; 247 if (!who) 248 uid = cred->uid; 249 else if (!uid_eq(uid, cred->uid)) { 250 user = find_user(uid); 251 if (!user) 252 goto out_unlock; /* No processes for this user */ 253 } 254 for_each_process_thread(g, p) { 255 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) 256 error = set_one_prio(p, niceval, error); 257 } 258 if (!uid_eq(uid, cred->uid)) 259 free_uid(user); /* For find_user() */ 260 break; 261 } 262 out_unlock: 263 rcu_read_unlock(); 264 out: 265 return error; 266 } 267 268 /* 269 * Ugh. To avoid negative return values, "getpriority()" will 270 * not return the normal nice-value, but a negated value that 271 * has been offset by 20 (ie it returns 40..1 instead of -20..19) 272 * to stay compatible. 273 */ 274 SYSCALL_DEFINE2(getpriority, int, which, int, who) 275 { 276 struct task_struct *g, *p; 277 struct user_struct *user; 278 const struct cred *cred = current_cred(); 279 long niceval, retval = -ESRCH; 280 struct pid *pgrp; 281 kuid_t uid; 282 283 if (which > PRIO_USER || which < PRIO_PROCESS) 284 return -EINVAL; 285 286 rcu_read_lock(); 287 switch (which) { 288 case PRIO_PROCESS: 289 if (who) 290 p = find_task_by_vpid(who); 291 else 292 p = current; 293 if (p) { 294 niceval = nice_to_rlimit(task_nice(p)); 295 if (niceval > retval) 296 retval = niceval; 297 } 298 break; 299 case PRIO_PGRP: 300 if (who) 301 pgrp = find_vpid(who); 302 else 303 pgrp = task_pgrp(current); 304 read_lock(&tasklist_lock); 305 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { 306 niceval = nice_to_rlimit(task_nice(p)); 307 if (niceval > retval) 308 retval = niceval; 309 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); 310 read_unlock(&tasklist_lock); 311 break; 312 case PRIO_USER: 313 uid = make_kuid(cred->user_ns, who); 314 user = cred->user; 315 if (!who) 316 uid = cred->uid; 317 else if (!uid_eq(uid, cred->uid)) { 318 user = find_user(uid); 319 if (!user) 320 goto out_unlock; /* No processes for this user */ 321 } 322 for_each_process_thread(g, p) { 323 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) { 324 niceval = nice_to_rlimit(task_nice(p)); 325 if (niceval > retval) 326 retval = niceval; 327 } 328 } 329 if (!uid_eq(uid, cred->uid)) 330 free_uid(user); /* for find_user() */ 331 break; 332 } 333 out_unlock: 334 rcu_read_unlock(); 335 336 return retval; 337 } 338 339 /* 340 * Unprivileged users may change the real gid to the effective gid 341 * or vice versa. (BSD-style) 342 * 343 * If you set the real gid at all, or set the effective gid to a value not 344 * equal to the real gid, then the saved gid is set to the new effective gid. 345 * 346 * This makes it possible for a setgid program to completely drop its 347 * privileges, which is often a useful assertion to make when you are doing 348 * a security audit over a program. 349 * 350 * The general idea is that a program which uses just setregid() will be 351 * 100% compatible with BSD. A program which uses just setgid() will be 352 * 100% compatible with POSIX with saved IDs. 353 * 354 * SMP: There are not races, the GIDs are checked only by filesystem 355 * operations (as far as semantic preservation is concerned). 356 */ 357 #ifdef CONFIG_MULTIUSER 358 long __sys_setregid(gid_t rgid, gid_t egid) 359 { 360 struct user_namespace *ns = current_user_ns(); 361 const struct cred *old; 362 struct cred *new; 363 int retval; 364 kgid_t krgid, kegid; 365 366 krgid = make_kgid(ns, rgid); 367 kegid = make_kgid(ns, egid); 368 369 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 370 return -EINVAL; 371 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 372 return -EINVAL; 373 374 new = prepare_creds(); 375 if (!new) 376 return -ENOMEM; 377 old = current_cred(); 378 379 retval = -EPERM; 380 if (rgid != (gid_t) -1) { 381 if (gid_eq(old->gid, krgid) || 382 gid_eq(old->egid, krgid) || 383 ns_capable_setid(old->user_ns, CAP_SETGID)) 384 new->gid = krgid; 385 else 386 goto error; 387 } 388 if (egid != (gid_t) -1) { 389 if (gid_eq(old->gid, kegid) || 390 gid_eq(old->egid, kegid) || 391 gid_eq(old->sgid, kegid) || 392 ns_capable_setid(old->user_ns, CAP_SETGID)) 393 new->egid = kegid; 394 else 395 goto error; 396 } 397 398 if (rgid != (gid_t) -1 || 399 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) 400 new->sgid = new->egid; 401 new->fsgid = new->egid; 402 403 retval = security_task_fix_setgid(new, old, LSM_SETID_RE); 404 if (retval < 0) 405 goto error; 406 407 return commit_creds(new); 408 409 error: 410 abort_creds(new); 411 return retval; 412 } 413 414 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) 415 { 416 return __sys_setregid(rgid, egid); 417 } 418 419 /* 420 * setgid() is implemented like SysV w/ SAVED_IDS 421 * 422 * SMP: Same implicit races as above. 423 */ 424 long __sys_setgid(gid_t gid) 425 { 426 struct user_namespace *ns = current_user_ns(); 427 const struct cred *old; 428 struct cred *new; 429 int retval; 430 kgid_t kgid; 431 432 kgid = make_kgid(ns, gid); 433 if (!gid_valid(kgid)) 434 return -EINVAL; 435 436 new = prepare_creds(); 437 if (!new) 438 return -ENOMEM; 439 old = current_cred(); 440 441 retval = -EPERM; 442 if (ns_capable_setid(old->user_ns, CAP_SETGID)) 443 new->gid = new->egid = new->sgid = new->fsgid = kgid; 444 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) 445 new->egid = new->fsgid = kgid; 446 else 447 goto error; 448 449 retval = security_task_fix_setgid(new, old, LSM_SETID_ID); 450 if (retval < 0) 451 goto error; 452 453 return commit_creds(new); 454 455 error: 456 abort_creds(new); 457 return retval; 458 } 459 460 SYSCALL_DEFINE1(setgid, gid_t, gid) 461 { 462 return __sys_setgid(gid); 463 } 464 465 /* 466 * change the user struct in a credentials set to match the new UID 467 */ 468 static int set_user(struct cred *new) 469 { 470 struct user_struct *new_user; 471 472 new_user = alloc_uid(new->uid); 473 if (!new_user) 474 return -EAGAIN; 475 476 free_uid(new->user); 477 new->user = new_user; 478 return 0; 479 } 480 481 static void flag_nproc_exceeded(struct cred *new) 482 { 483 if (new->ucounts == current_ucounts()) 484 return; 485 486 /* 487 * We don't fail in case of NPROC limit excess here because too many 488 * poorly written programs don't check set*uid() return code, assuming 489 * it never fails if called by root. We may still enforce NPROC limit 490 * for programs doing set*uid()+execve() by harmlessly deferring the 491 * failure to the execve() stage. 492 */ 493 if (is_ucounts_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) && 494 new->user != INIT_USER) 495 current->flags |= PF_NPROC_EXCEEDED; 496 else 497 current->flags &= ~PF_NPROC_EXCEEDED; 498 } 499 500 /* 501 * Unprivileged users may change the real uid to the effective uid 502 * or vice versa. (BSD-style) 503 * 504 * If you set the real uid at all, or set the effective uid to a value not 505 * equal to the real uid, then the saved uid is set to the new effective uid. 506 * 507 * This makes it possible for a setuid program to completely drop its 508 * privileges, which is often a useful assertion to make when you are doing 509 * a security audit over a program. 510 * 511 * The general idea is that a program which uses just setreuid() will be 512 * 100% compatible with BSD. A program which uses just setuid() will be 513 * 100% compatible with POSIX with saved IDs. 514 */ 515 long __sys_setreuid(uid_t ruid, uid_t euid) 516 { 517 struct user_namespace *ns = current_user_ns(); 518 const struct cred *old; 519 struct cred *new; 520 int retval; 521 kuid_t kruid, keuid; 522 523 kruid = make_kuid(ns, ruid); 524 keuid = make_kuid(ns, euid); 525 526 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 527 return -EINVAL; 528 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 529 return -EINVAL; 530 531 new = prepare_creds(); 532 if (!new) 533 return -ENOMEM; 534 old = current_cred(); 535 536 retval = -EPERM; 537 if (ruid != (uid_t) -1) { 538 new->uid = kruid; 539 if (!uid_eq(old->uid, kruid) && 540 !uid_eq(old->euid, kruid) && 541 !ns_capable_setid(old->user_ns, CAP_SETUID)) 542 goto error; 543 } 544 545 if (euid != (uid_t) -1) { 546 new->euid = keuid; 547 if (!uid_eq(old->uid, keuid) && 548 !uid_eq(old->euid, keuid) && 549 !uid_eq(old->suid, keuid) && 550 !ns_capable_setid(old->user_ns, CAP_SETUID)) 551 goto error; 552 } 553 554 if (!uid_eq(new->uid, old->uid)) { 555 retval = set_user(new); 556 if (retval < 0) 557 goto error; 558 } 559 if (ruid != (uid_t) -1 || 560 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) 561 new->suid = new->euid; 562 new->fsuid = new->euid; 563 564 retval = security_task_fix_setuid(new, old, LSM_SETID_RE); 565 if (retval < 0) 566 goto error; 567 568 retval = set_cred_ucounts(new); 569 if (retval < 0) 570 goto error; 571 572 flag_nproc_exceeded(new); 573 return commit_creds(new); 574 575 error: 576 abort_creds(new); 577 return retval; 578 } 579 580 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) 581 { 582 return __sys_setreuid(ruid, euid); 583 } 584 585 /* 586 * setuid() is implemented like SysV with SAVED_IDS 587 * 588 * Note that SAVED_ID's is deficient in that a setuid root program 589 * like sendmail, for example, cannot set its uid to be a normal 590 * user and then switch back, because if you're root, setuid() sets 591 * the saved uid too. If you don't like this, blame the bright people 592 * in the POSIX committee and/or USG. Note that the BSD-style setreuid() 593 * will allow a root program to temporarily drop privileges and be able to 594 * regain them by swapping the real and effective uid. 595 */ 596 long __sys_setuid(uid_t uid) 597 { 598 struct user_namespace *ns = current_user_ns(); 599 const struct cred *old; 600 struct cred *new; 601 int retval; 602 kuid_t kuid; 603 604 kuid = make_kuid(ns, uid); 605 if (!uid_valid(kuid)) 606 return -EINVAL; 607 608 new = prepare_creds(); 609 if (!new) 610 return -ENOMEM; 611 old = current_cred(); 612 613 retval = -EPERM; 614 if (ns_capable_setid(old->user_ns, CAP_SETUID)) { 615 new->suid = new->uid = kuid; 616 if (!uid_eq(kuid, old->uid)) { 617 retval = set_user(new); 618 if (retval < 0) 619 goto error; 620 } 621 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { 622 goto error; 623 } 624 625 new->fsuid = new->euid = kuid; 626 627 retval = security_task_fix_setuid(new, old, LSM_SETID_ID); 628 if (retval < 0) 629 goto error; 630 631 retval = set_cred_ucounts(new); 632 if (retval < 0) 633 goto error; 634 635 flag_nproc_exceeded(new); 636 return commit_creds(new); 637 638 error: 639 abort_creds(new); 640 return retval; 641 } 642 643 SYSCALL_DEFINE1(setuid, uid_t, uid) 644 { 645 return __sys_setuid(uid); 646 } 647 648 649 /* 650 * This function implements a generic ability to update ruid, euid, 651 * and suid. This allows you to implement the 4.4 compatible seteuid(). 652 */ 653 long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid) 654 { 655 struct user_namespace *ns = current_user_ns(); 656 const struct cred *old; 657 struct cred *new; 658 int retval; 659 kuid_t kruid, keuid, ksuid; 660 661 kruid = make_kuid(ns, ruid); 662 keuid = make_kuid(ns, euid); 663 ksuid = make_kuid(ns, suid); 664 665 if ((ruid != (uid_t) -1) && !uid_valid(kruid)) 666 return -EINVAL; 667 668 if ((euid != (uid_t) -1) && !uid_valid(keuid)) 669 return -EINVAL; 670 671 if ((suid != (uid_t) -1) && !uid_valid(ksuid)) 672 return -EINVAL; 673 674 new = prepare_creds(); 675 if (!new) 676 return -ENOMEM; 677 678 old = current_cred(); 679 680 retval = -EPERM; 681 if (!ns_capable_setid(old->user_ns, CAP_SETUID)) { 682 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && 683 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid)) 684 goto error; 685 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && 686 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid)) 687 goto error; 688 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && 689 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid)) 690 goto error; 691 } 692 693 if (ruid != (uid_t) -1) { 694 new->uid = kruid; 695 if (!uid_eq(kruid, old->uid)) { 696 retval = set_user(new); 697 if (retval < 0) 698 goto error; 699 } 700 } 701 if (euid != (uid_t) -1) 702 new->euid = keuid; 703 if (suid != (uid_t) -1) 704 new->suid = ksuid; 705 new->fsuid = new->euid; 706 707 retval = security_task_fix_setuid(new, old, LSM_SETID_RES); 708 if (retval < 0) 709 goto error; 710 711 retval = set_cred_ucounts(new); 712 if (retval < 0) 713 goto error; 714 715 flag_nproc_exceeded(new); 716 return commit_creds(new); 717 718 error: 719 abort_creds(new); 720 return retval; 721 } 722 723 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) 724 { 725 return __sys_setresuid(ruid, euid, suid); 726 } 727 728 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) 729 { 730 const struct cred *cred = current_cred(); 731 int retval; 732 uid_t ruid, euid, suid; 733 734 ruid = from_kuid_munged(cred->user_ns, cred->uid); 735 euid = from_kuid_munged(cred->user_ns, cred->euid); 736 suid = from_kuid_munged(cred->user_ns, cred->suid); 737 738 retval = put_user(ruid, ruidp); 739 if (!retval) { 740 retval = put_user(euid, euidp); 741 if (!retval) 742 return put_user(suid, suidp); 743 } 744 return retval; 745 } 746 747 /* 748 * Same as above, but for rgid, egid, sgid. 749 */ 750 long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid) 751 { 752 struct user_namespace *ns = current_user_ns(); 753 const struct cred *old; 754 struct cred *new; 755 int retval; 756 kgid_t krgid, kegid, ksgid; 757 758 krgid = make_kgid(ns, rgid); 759 kegid = make_kgid(ns, egid); 760 ksgid = make_kgid(ns, sgid); 761 762 if ((rgid != (gid_t) -1) && !gid_valid(krgid)) 763 return -EINVAL; 764 if ((egid != (gid_t) -1) && !gid_valid(kegid)) 765 return -EINVAL; 766 if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) 767 return -EINVAL; 768 769 new = prepare_creds(); 770 if (!new) 771 return -ENOMEM; 772 old = current_cred(); 773 774 retval = -EPERM; 775 if (!ns_capable_setid(old->user_ns, CAP_SETGID)) { 776 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && 777 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid)) 778 goto error; 779 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && 780 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid)) 781 goto error; 782 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && 783 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid)) 784 goto error; 785 } 786 787 if (rgid != (gid_t) -1) 788 new->gid = krgid; 789 if (egid != (gid_t) -1) 790 new->egid = kegid; 791 if (sgid != (gid_t) -1) 792 new->sgid = ksgid; 793 new->fsgid = new->egid; 794 795 retval = security_task_fix_setgid(new, old, LSM_SETID_RES); 796 if (retval < 0) 797 goto error; 798 799 return commit_creds(new); 800 801 error: 802 abort_creds(new); 803 return retval; 804 } 805 806 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) 807 { 808 return __sys_setresgid(rgid, egid, sgid); 809 } 810 811 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) 812 { 813 const struct cred *cred = current_cred(); 814 int retval; 815 gid_t rgid, egid, sgid; 816 817 rgid = from_kgid_munged(cred->user_ns, cred->gid); 818 egid = from_kgid_munged(cred->user_ns, cred->egid); 819 sgid = from_kgid_munged(cred->user_ns, cred->sgid); 820 821 retval = put_user(rgid, rgidp); 822 if (!retval) { 823 retval = put_user(egid, egidp); 824 if (!retval) 825 retval = put_user(sgid, sgidp); 826 } 827 828 return retval; 829 } 830 831 832 /* 833 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This 834 * is used for "access()" and for the NFS daemon (letting nfsd stay at 835 * whatever uid it wants to). It normally shadows "euid", except when 836 * explicitly set by setfsuid() or for access.. 837 */ 838 long __sys_setfsuid(uid_t uid) 839 { 840 const struct cred *old; 841 struct cred *new; 842 uid_t old_fsuid; 843 kuid_t kuid; 844 845 old = current_cred(); 846 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); 847 848 kuid = make_kuid(old->user_ns, uid); 849 if (!uid_valid(kuid)) 850 return old_fsuid; 851 852 new = prepare_creds(); 853 if (!new) 854 return old_fsuid; 855 856 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || 857 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || 858 ns_capable_setid(old->user_ns, CAP_SETUID)) { 859 if (!uid_eq(kuid, old->fsuid)) { 860 new->fsuid = kuid; 861 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) 862 goto change_okay; 863 } 864 } 865 866 abort_creds(new); 867 return old_fsuid; 868 869 change_okay: 870 commit_creds(new); 871 return old_fsuid; 872 } 873 874 SYSCALL_DEFINE1(setfsuid, uid_t, uid) 875 { 876 return __sys_setfsuid(uid); 877 } 878 879 /* 880 * Samma på svenska.. 881 */ 882 long __sys_setfsgid(gid_t gid) 883 { 884 const struct cred *old; 885 struct cred *new; 886 gid_t old_fsgid; 887 kgid_t kgid; 888 889 old = current_cred(); 890 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); 891 892 kgid = make_kgid(old->user_ns, gid); 893 if (!gid_valid(kgid)) 894 return old_fsgid; 895 896 new = prepare_creds(); 897 if (!new) 898 return old_fsgid; 899 900 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || 901 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || 902 ns_capable_setid(old->user_ns, CAP_SETGID)) { 903 if (!gid_eq(kgid, old->fsgid)) { 904 new->fsgid = kgid; 905 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0) 906 goto change_okay; 907 } 908 } 909 910 abort_creds(new); 911 return old_fsgid; 912 913 change_okay: 914 commit_creds(new); 915 return old_fsgid; 916 } 917 918 SYSCALL_DEFINE1(setfsgid, gid_t, gid) 919 { 920 return __sys_setfsgid(gid); 921 } 922 #endif /* CONFIG_MULTIUSER */ 923 924 /** 925 * sys_getpid - return the thread group id of the current process 926 * 927 * Note, despite the name, this returns the tgid not the pid. The tgid and 928 * the pid are identical unless CLONE_THREAD was specified on clone() in 929 * which case the tgid is the same in all threads of the same group. 930 * 931 * This is SMP safe as current->tgid does not change. 932 */ 933 SYSCALL_DEFINE0(getpid) 934 { 935 return task_tgid_vnr(current); 936 } 937 938 /* Thread ID - the internal kernel "pid" */ 939 SYSCALL_DEFINE0(gettid) 940 { 941 return task_pid_vnr(current); 942 } 943 944 /* 945 * Accessing ->real_parent is not SMP-safe, it could 946 * change from under us. However, we can use a stale 947 * value of ->real_parent under rcu_read_lock(), see 948 * release_task()->call_rcu(delayed_put_task_struct). 949 */ 950 SYSCALL_DEFINE0(getppid) 951 { 952 int pid; 953 954 rcu_read_lock(); 955 pid = task_tgid_vnr(rcu_dereference(current->real_parent)); 956 rcu_read_unlock(); 957 958 return pid; 959 } 960 961 SYSCALL_DEFINE0(getuid) 962 { 963 /* Only we change this so SMP safe */ 964 return from_kuid_munged(current_user_ns(), current_uid()); 965 } 966 967 SYSCALL_DEFINE0(geteuid) 968 { 969 /* Only we change this so SMP safe */ 970 return from_kuid_munged(current_user_ns(), current_euid()); 971 } 972 973 SYSCALL_DEFINE0(getgid) 974 { 975 /* Only we change this so SMP safe */ 976 return from_kgid_munged(current_user_ns(), current_gid()); 977 } 978 979 SYSCALL_DEFINE0(getegid) 980 { 981 /* Only we change this so SMP safe */ 982 return from_kgid_munged(current_user_ns(), current_egid()); 983 } 984 985 static void do_sys_times(struct tms *tms) 986 { 987 u64 tgutime, tgstime, cutime, cstime; 988 989 thread_group_cputime_adjusted(current, &tgutime, &tgstime); 990 cutime = current->signal->cutime; 991 cstime = current->signal->cstime; 992 tms->tms_utime = nsec_to_clock_t(tgutime); 993 tms->tms_stime = nsec_to_clock_t(tgstime); 994 tms->tms_cutime = nsec_to_clock_t(cutime); 995 tms->tms_cstime = nsec_to_clock_t(cstime); 996 } 997 998 SYSCALL_DEFINE1(times, struct tms __user *, tbuf) 999 { 1000 if (tbuf) { 1001 struct tms tmp; 1002 1003 do_sys_times(&tmp); 1004 if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) 1005 return -EFAULT; 1006 } 1007 force_successful_syscall_return(); 1008 return (long) jiffies_64_to_clock_t(get_jiffies_64()); 1009 } 1010 1011 #ifdef CONFIG_COMPAT 1012 static compat_clock_t clock_t_to_compat_clock_t(clock_t x) 1013 { 1014 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x)); 1015 } 1016 1017 COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf) 1018 { 1019 if (tbuf) { 1020 struct tms tms; 1021 struct compat_tms tmp; 1022 1023 do_sys_times(&tms); 1024 /* Convert our struct tms to the compat version. */ 1025 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime); 1026 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime); 1027 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime); 1028 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime); 1029 if (copy_to_user(tbuf, &tmp, sizeof(tmp))) 1030 return -EFAULT; 1031 } 1032 force_successful_syscall_return(); 1033 return compat_jiffies_to_clock_t(jiffies); 1034 } 1035 #endif 1036 1037 /* 1038 * This needs some heavy checking ... 1039 * I just haven't the stomach for it. I also don't fully 1040 * understand sessions/pgrp etc. Let somebody who does explain it. 1041 * 1042 * OK, I think I have the protection semantics right.... this is really 1043 * only important on a multi-user system anyway, to make sure one user 1044 * can't send a signal to a process owned by another. -TYT, 12/12/91 1045 * 1046 * !PF_FORKNOEXEC check to conform completely to POSIX. 1047 */ 1048 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) 1049 { 1050 struct task_struct *p; 1051 struct task_struct *group_leader = current->group_leader; 1052 struct pid *pgrp; 1053 int err; 1054 1055 if (!pid) 1056 pid = task_pid_vnr(group_leader); 1057 if (!pgid) 1058 pgid = pid; 1059 if (pgid < 0) 1060 return -EINVAL; 1061 rcu_read_lock(); 1062 1063 /* From this point forward we keep holding onto the tasklist lock 1064 * so that our parent does not change from under us. -DaveM 1065 */ 1066 write_lock_irq(&tasklist_lock); 1067 1068 err = -ESRCH; 1069 p = find_task_by_vpid(pid); 1070 if (!p) 1071 goto out; 1072 1073 err = -EINVAL; 1074 if (!thread_group_leader(p)) 1075 goto out; 1076 1077 if (same_thread_group(p->real_parent, group_leader)) { 1078 err = -EPERM; 1079 if (task_session(p) != task_session(group_leader)) 1080 goto out; 1081 err = -EACCES; 1082 if (!(p->flags & PF_FORKNOEXEC)) 1083 goto out; 1084 } else { 1085 err = -ESRCH; 1086 if (p != group_leader) 1087 goto out; 1088 } 1089 1090 err = -EPERM; 1091 if (p->signal->leader) 1092 goto out; 1093 1094 pgrp = task_pid(p); 1095 if (pgid != pid) { 1096 struct task_struct *g; 1097 1098 pgrp = find_vpid(pgid); 1099 g = pid_task(pgrp, PIDTYPE_PGID); 1100 if (!g || task_session(g) != task_session(group_leader)) 1101 goto out; 1102 } 1103 1104 err = security_task_setpgid(p, pgid); 1105 if (err) 1106 goto out; 1107 1108 if (task_pgrp(p) != pgrp) 1109 change_pid(p, PIDTYPE_PGID, pgrp); 1110 1111 err = 0; 1112 out: 1113 /* All paths lead to here, thus we are safe. -DaveM */ 1114 write_unlock_irq(&tasklist_lock); 1115 rcu_read_unlock(); 1116 return err; 1117 } 1118 1119 static int do_getpgid(pid_t pid) 1120 { 1121 struct task_struct *p; 1122 struct pid *grp; 1123 int retval; 1124 1125 rcu_read_lock(); 1126 if (!pid) 1127 grp = task_pgrp(current); 1128 else { 1129 retval = -ESRCH; 1130 p = find_task_by_vpid(pid); 1131 if (!p) 1132 goto out; 1133 grp = task_pgrp(p); 1134 if (!grp) 1135 goto out; 1136 1137 retval = security_task_getpgid(p); 1138 if (retval) 1139 goto out; 1140 } 1141 retval = pid_vnr(grp); 1142 out: 1143 rcu_read_unlock(); 1144 return retval; 1145 } 1146 1147 SYSCALL_DEFINE1(getpgid, pid_t, pid) 1148 { 1149 return do_getpgid(pid); 1150 } 1151 1152 #ifdef __ARCH_WANT_SYS_GETPGRP 1153 1154 SYSCALL_DEFINE0(getpgrp) 1155 { 1156 return do_getpgid(0); 1157 } 1158 1159 #endif 1160 1161 SYSCALL_DEFINE1(getsid, pid_t, pid) 1162 { 1163 struct task_struct *p; 1164 struct pid *sid; 1165 int retval; 1166 1167 rcu_read_lock(); 1168 if (!pid) 1169 sid = task_session(current); 1170 else { 1171 retval = -ESRCH; 1172 p = find_task_by_vpid(pid); 1173 if (!p) 1174 goto out; 1175 sid = task_session(p); 1176 if (!sid) 1177 goto out; 1178 1179 retval = security_task_getsid(p); 1180 if (retval) 1181 goto out; 1182 } 1183 retval = pid_vnr(sid); 1184 out: 1185 rcu_read_unlock(); 1186 return retval; 1187 } 1188 1189 static void set_special_pids(struct pid *pid) 1190 { 1191 struct task_struct *curr = current->group_leader; 1192 1193 if (task_session(curr) != pid) 1194 change_pid(curr, PIDTYPE_SID, pid); 1195 1196 if (task_pgrp(curr) != pid) 1197 change_pid(curr, PIDTYPE_PGID, pid); 1198 } 1199 1200 int ksys_setsid(void) 1201 { 1202 struct task_struct *group_leader = current->group_leader; 1203 struct pid *sid = task_pid(group_leader); 1204 pid_t session = pid_vnr(sid); 1205 int err = -EPERM; 1206 1207 write_lock_irq(&tasklist_lock); 1208 /* Fail if I am already a session leader */ 1209 if (group_leader->signal->leader) 1210 goto out; 1211 1212 /* Fail if a process group id already exists that equals the 1213 * proposed session id. 1214 */ 1215 if (pid_task(sid, PIDTYPE_PGID)) 1216 goto out; 1217 1218 group_leader->signal->leader = 1; 1219 set_special_pids(sid); 1220 1221 proc_clear_tty(group_leader); 1222 1223 err = session; 1224 out: 1225 write_unlock_irq(&tasklist_lock); 1226 if (err > 0) { 1227 proc_sid_connector(group_leader); 1228 sched_autogroup_create_attach(group_leader); 1229 } 1230 return err; 1231 } 1232 1233 SYSCALL_DEFINE0(setsid) 1234 { 1235 return ksys_setsid(); 1236 } 1237 1238 DECLARE_RWSEM(uts_sem); 1239 1240 #ifdef COMPAT_UTS_MACHINE 1241 #define override_architecture(name) \ 1242 (personality(current->personality) == PER_LINUX32 && \ 1243 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ 1244 sizeof(COMPAT_UTS_MACHINE))) 1245 #else 1246 #define override_architecture(name) 0 1247 #endif 1248 1249 /* 1250 * Work around broken programs that cannot handle "Linux 3.0". 1251 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 1252 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be 1253 * 2.6.60. 1254 */ 1255 static int override_release(char __user *release, size_t len) 1256 { 1257 int ret = 0; 1258 1259 if (current->personality & UNAME26) { 1260 const char *rest = UTS_RELEASE; 1261 char buf[65] = { 0 }; 1262 int ndots = 0; 1263 unsigned v; 1264 size_t copy; 1265 1266 while (*rest) { 1267 if (*rest == '.' && ++ndots >= 3) 1268 break; 1269 if (!isdigit(*rest) && *rest != '.') 1270 break; 1271 rest++; 1272 } 1273 v = LINUX_VERSION_PATCHLEVEL + 60; 1274 copy = clamp_t(size_t, len, 1, sizeof(buf)); 1275 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); 1276 ret = copy_to_user(release, buf, copy + 1); 1277 } 1278 return ret; 1279 } 1280 1281 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) 1282 { 1283 struct new_utsname tmp; 1284 1285 down_read(&uts_sem); 1286 memcpy(&tmp, utsname(), sizeof(tmp)); 1287 up_read(&uts_sem); 1288 if (copy_to_user(name, &tmp, sizeof(tmp))) 1289 return -EFAULT; 1290 1291 if (override_release(name->release, sizeof(name->release))) 1292 return -EFAULT; 1293 if (override_architecture(name)) 1294 return -EFAULT; 1295 return 0; 1296 } 1297 1298 #ifdef __ARCH_WANT_SYS_OLD_UNAME 1299 /* 1300 * Old cruft 1301 */ 1302 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) 1303 { 1304 struct old_utsname tmp; 1305 1306 if (!name) 1307 return -EFAULT; 1308 1309 down_read(&uts_sem); 1310 memcpy(&tmp, utsname(), sizeof(tmp)); 1311 up_read(&uts_sem); 1312 if (copy_to_user(name, &tmp, sizeof(tmp))) 1313 return -EFAULT; 1314 1315 if (override_release(name->release, sizeof(name->release))) 1316 return -EFAULT; 1317 if (override_architecture(name)) 1318 return -EFAULT; 1319 return 0; 1320 } 1321 1322 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) 1323 { 1324 struct oldold_utsname tmp; 1325 1326 if (!name) 1327 return -EFAULT; 1328 1329 memset(&tmp, 0, sizeof(tmp)); 1330 1331 down_read(&uts_sem); 1332 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN); 1333 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN); 1334 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN); 1335 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN); 1336 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN); 1337 up_read(&uts_sem); 1338 if (copy_to_user(name, &tmp, sizeof(tmp))) 1339 return -EFAULT; 1340 1341 if (override_architecture(name)) 1342 return -EFAULT; 1343 if (override_release(name->release, sizeof(name->release))) 1344 return -EFAULT; 1345 return 0; 1346 } 1347 #endif 1348 1349 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) 1350 { 1351 int errno; 1352 char tmp[__NEW_UTS_LEN]; 1353 1354 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1355 return -EPERM; 1356 1357 if (len < 0 || len > __NEW_UTS_LEN) 1358 return -EINVAL; 1359 errno = -EFAULT; 1360 if (!copy_from_user(tmp, name, len)) { 1361 struct new_utsname *u; 1362 1363 down_write(&uts_sem); 1364 u = utsname(); 1365 memcpy(u->nodename, tmp, len); 1366 memset(u->nodename + len, 0, sizeof(u->nodename) - len); 1367 errno = 0; 1368 uts_proc_notify(UTS_PROC_HOSTNAME); 1369 up_write(&uts_sem); 1370 } 1371 return errno; 1372 } 1373 1374 #ifdef __ARCH_WANT_SYS_GETHOSTNAME 1375 1376 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) 1377 { 1378 int i; 1379 struct new_utsname *u; 1380 char tmp[__NEW_UTS_LEN + 1]; 1381 1382 if (len < 0) 1383 return -EINVAL; 1384 down_read(&uts_sem); 1385 u = utsname(); 1386 i = 1 + strlen(u->nodename); 1387 if (i > len) 1388 i = len; 1389 memcpy(tmp, u->nodename, i); 1390 up_read(&uts_sem); 1391 if (copy_to_user(name, tmp, i)) 1392 return -EFAULT; 1393 return 0; 1394 } 1395 1396 #endif 1397 1398 /* 1399 * Only setdomainname; getdomainname can be implemented by calling 1400 * uname() 1401 */ 1402 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) 1403 { 1404 int errno; 1405 char tmp[__NEW_UTS_LEN]; 1406 1407 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) 1408 return -EPERM; 1409 if (len < 0 || len > __NEW_UTS_LEN) 1410 return -EINVAL; 1411 1412 errno = -EFAULT; 1413 if (!copy_from_user(tmp, name, len)) { 1414 struct new_utsname *u; 1415 1416 down_write(&uts_sem); 1417 u = utsname(); 1418 memcpy(u->domainname, tmp, len); 1419 memset(u->domainname + len, 0, sizeof(u->domainname) - len); 1420 errno = 0; 1421 uts_proc_notify(UTS_PROC_DOMAINNAME); 1422 up_write(&uts_sem); 1423 } 1424 return errno; 1425 } 1426 1427 /* make sure you are allowed to change @tsk limits before calling this */ 1428 static int do_prlimit(struct task_struct *tsk, unsigned int resource, 1429 struct rlimit *new_rlim, struct rlimit *old_rlim) 1430 { 1431 struct rlimit *rlim; 1432 int retval = 0; 1433 1434 if (resource >= RLIM_NLIMITS) 1435 return -EINVAL; 1436 if (new_rlim) { 1437 if (new_rlim->rlim_cur > new_rlim->rlim_max) 1438 return -EINVAL; 1439 if (resource == RLIMIT_NOFILE && 1440 new_rlim->rlim_max > sysctl_nr_open) 1441 return -EPERM; 1442 } 1443 1444 /* Holding a refcount on tsk protects tsk->signal from disappearing. */ 1445 rlim = tsk->signal->rlim + resource; 1446 task_lock(tsk->group_leader); 1447 if (new_rlim) { 1448 /* 1449 * Keep the capable check against init_user_ns until cgroups can 1450 * contain all limits. 1451 */ 1452 if (new_rlim->rlim_max > rlim->rlim_max && 1453 !capable(CAP_SYS_RESOURCE)) 1454 retval = -EPERM; 1455 if (!retval) 1456 retval = security_task_setrlimit(tsk, resource, new_rlim); 1457 } 1458 if (!retval) { 1459 if (old_rlim) 1460 *old_rlim = *rlim; 1461 if (new_rlim) 1462 *rlim = *new_rlim; 1463 } 1464 task_unlock(tsk->group_leader); 1465 1466 /* 1467 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not 1468 * infinite. In case of RLIM_INFINITY the posix CPU timer code 1469 * ignores the rlimit. 1470 */ 1471 if (!retval && new_rlim && resource == RLIMIT_CPU && 1472 new_rlim->rlim_cur != RLIM_INFINITY && 1473 IS_ENABLED(CONFIG_POSIX_TIMERS)) { 1474 /* 1475 * update_rlimit_cpu can fail if the task is exiting, but there 1476 * may be other tasks in the thread group that are not exiting, 1477 * and they need their cpu timers adjusted. 1478 * 1479 * The group_leader is the last task to be released, so if we 1480 * cannot update_rlimit_cpu on it, then the entire process is 1481 * exiting and we do not need to update at all. 1482 */ 1483 update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur); 1484 } 1485 1486 return retval; 1487 } 1488 1489 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1490 { 1491 struct rlimit value; 1492 int ret; 1493 1494 ret = do_prlimit(current, resource, NULL, &value); 1495 if (!ret) 1496 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; 1497 1498 return ret; 1499 } 1500 1501 #ifdef CONFIG_COMPAT 1502 1503 COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource, 1504 struct compat_rlimit __user *, rlim) 1505 { 1506 struct rlimit r; 1507 struct compat_rlimit r32; 1508 1509 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit))) 1510 return -EFAULT; 1511 1512 if (r32.rlim_cur == COMPAT_RLIM_INFINITY) 1513 r.rlim_cur = RLIM_INFINITY; 1514 else 1515 r.rlim_cur = r32.rlim_cur; 1516 if (r32.rlim_max == COMPAT_RLIM_INFINITY) 1517 r.rlim_max = RLIM_INFINITY; 1518 else 1519 r.rlim_max = r32.rlim_max; 1520 return do_prlimit(current, resource, &r, NULL); 1521 } 1522 1523 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource, 1524 struct compat_rlimit __user *, rlim) 1525 { 1526 struct rlimit r; 1527 int ret; 1528 1529 ret = do_prlimit(current, resource, NULL, &r); 1530 if (!ret) { 1531 struct compat_rlimit r32; 1532 if (r.rlim_cur > COMPAT_RLIM_INFINITY) 1533 r32.rlim_cur = COMPAT_RLIM_INFINITY; 1534 else 1535 r32.rlim_cur = r.rlim_cur; 1536 if (r.rlim_max > COMPAT_RLIM_INFINITY) 1537 r32.rlim_max = COMPAT_RLIM_INFINITY; 1538 else 1539 r32.rlim_max = r.rlim_max; 1540 1541 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit))) 1542 return -EFAULT; 1543 } 1544 return ret; 1545 } 1546 1547 #endif 1548 1549 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT 1550 1551 /* 1552 * Back compatibility for getrlimit. Needed for some apps. 1553 */ 1554 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1555 struct rlimit __user *, rlim) 1556 { 1557 struct rlimit x; 1558 if (resource >= RLIM_NLIMITS) 1559 return -EINVAL; 1560 1561 resource = array_index_nospec(resource, RLIM_NLIMITS); 1562 task_lock(current->group_leader); 1563 x = current->signal->rlim[resource]; 1564 task_unlock(current->group_leader); 1565 if (x.rlim_cur > 0x7FFFFFFF) 1566 x.rlim_cur = 0x7FFFFFFF; 1567 if (x.rlim_max > 0x7FFFFFFF) 1568 x.rlim_max = 0x7FFFFFFF; 1569 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0; 1570 } 1571 1572 #ifdef CONFIG_COMPAT 1573 COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, 1574 struct compat_rlimit __user *, rlim) 1575 { 1576 struct rlimit r; 1577 1578 if (resource >= RLIM_NLIMITS) 1579 return -EINVAL; 1580 1581 resource = array_index_nospec(resource, RLIM_NLIMITS); 1582 task_lock(current->group_leader); 1583 r = current->signal->rlim[resource]; 1584 task_unlock(current->group_leader); 1585 if (r.rlim_cur > 0x7FFFFFFF) 1586 r.rlim_cur = 0x7FFFFFFF; 1587 if (r.rlim_max > 0x7FFFFFFF) 1588 r.rlim_max = 0x7FFFFFFF; 1589 1590 if (put_user(r.rlim_cur, &rlim->rlim_cur) || 1591 put_user(r.rlim_max, &rlim->rlim_max)) 1592 return -EFAULT; 1593 return 0; 1594 } 1595 #endif 1596 1597 #endif 1598 1599 static inline bool rlim64_is_infinity(__u64 rlim64) 1600 { 1601 #if BITS_PER_LONG < 64 1602 return rlim64 >= ULONG_MAX; 1603 #else 1604 return rlim64 == RLIM64_INFINITY; 1605 #endif 1606 } 1607 1608 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) 1609 { 1610 if (rlim->rlim_cur == RLIM_INFINITY) 1611 rlim64->rlim_cur = RLIM64_INFINITY; 1612 else 1613 rlim64->rlim_cur = rlim->rlim_cur; 1614 if (rlim->rlim_max == RLIM_INFINITY) 1615 rlim64->rlim_max = RLIM64_INFINITY; 1616 else 1617 rlim64->rlim_max = rlim->rlim_max; 1618 } 1619 1620 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) 1621 { 1622 if (rlim64_is_infinity(rlim64->rlim_cur)) 1623 rlim->rlim_cur = RLIM_INFINITY; 1624 else 1625 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; 1626 if (rlim64_is_infinity(rlim64->rlim_max)) 1627 rlim->rlim_max = RLIM_INFINITY; 1628 else 1629 rlim->rlim_max = (unsigned long)rlim64->rlim_max; 1630 } 1631 1632 /* rcu lock must be held */ 1633 static int check_prlimit_permission(struct task_struct *task, 1634 unsigned int flags) 1635 { 1636 const struct cred *cred = current_cred(), *tcred; 1637 bool id_match; 1638 1639 if (current == task) 1640 return 0; 1641 1642 tcred = __task_cred(task); 1643 id_match = (uid_eq(cred->uid, tcred->euid) && 1644 uid_eq(cred->uid, tcred->suid) && 1645 uid_eq(cred->uid, tcred->uid) && 1646 gid_eq(cred->gid, tcred->egid) && 1647 gid_eq(cred->gid, tcred->sgid) && 1648 gid_eq(cred->gid, tcred->gid)); 1649 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) 1650 return -EPERM; 1651 1652 return security_task_prlimit(cred, tcred, flags); 1653 } 1654 1655 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, 1656 const struct rlimit64 __user *, new_rlim, 1657 struct rlimit64 __user *, old_rlim) 1658 { 1659 struct rlimit64 old64, new64; 1660 struct rlimit old, new; 1661 struct task_struct *tsk; 1662 unsigned int checkflags = 0; 1663 int ret; 1664 1665 if (old_rlim) 1666 checkflags |= LSM_PRLIMIT_READ; 1667 1668 if (new_rlim) { 1669 if (copy_from_user(&new64, new_rlim, sizeof(new64))) 1670 return -EFAULT; 1671 rlim64_to_rlim(&new64, &new); 1672 checkflags |= LSM_PRLIMIT_WRITE; 1673 } 1674 1675 rcu_read_lock(); 1676 tsk = pid ? find_task_by_vpid(pid) : current; 1677 if (!tsk) { 1678 rcu_read_unlock(); 1679 return -ESRCH; 1680 } 1681 ret = check_prlimit_permission(tsk, checkflags); 1682 if (ret) { 1683 rcu_read_unlock(); 1684 return ret; 1685 } 1686 get_task_struct(tsk); 1687 rcu_read_unlock(); 1688 1689 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, 1690 old_rlim ? &old : NULL); 1691 1692 if (!ret && old_rlim) { 1693 rlim_to_rlim64(&old, &old64); 1694 if (copy_to_user(old_rlim, &old64, sizeof(old64))) 1695 ret = -EFAULT; 1696 } 1697 1698 put_task_struct(tsk); 1699 return ret; 1700 } 1701 1702 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) 1703 { 1704 struct rlimit new_rlim; 1705 1706 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) 1707 return -EFAULT; 1708 return do_prlimit(current, resource, &new_rlim, NULL); 1709 } 1710 1711 /* 1712 * It would make sense to put struct rusage in the task_struct, 1713 * except that would make the task_struct be *really big*. After 1714 * task_struct gets moved into malloc'ed memory, it would 1715 * make sense to do this. It will make moving the rest of the information 1716 * a lot simpler! (Which we're not doing right now because we're not 1717 * measuring them yet). 1718 * 1719 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have 1720 * races with threads incrementing their own counters. But since word 1721 * reads are atomic, we either get new values or old values and we don't 1722 * care which for the sums. We always take the siglock to protect reading 1723 * the c* fields from p->signal from races with exit.c updating those 1724 * fields when reaping, so a sample either gets all the additions of a 1725 * given child after it's reaped, or none so this sample is before reaping. 1726 * 1727 * Locking: 1728 * We need to take the siglock for CHILDEREN, SELF and BOTH 1729 * for the cases current multithreaded, non-current single threaded 1730 * non-current multithreaded. Thread traversal is now safe with 1731 * the siglock held. 1732 * Strictly speaking, we donot need to take the siglock if we are current and 1733 * single threaded, as no one else can take our signal_struct away, no one 1734 * else can reap the children to update signal->c* counters, and no one else 1735 * can race with the signal-> fields. If we do not take any lock, the 1736 * signal-> fields could be read out of order while another thread was just 1737 * exiting. So we should place a read memory barrier when we avoid the lock. 1738 * On the writer side, write memory barrier is implied in __exit_signal 1739 * as __exit_signal releases the siglock spinlock after updating the signal-> 1740 * fields. But we don't do this yet to keep things simple. 1741 * 1742 */ 1743 1744 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) 1745 { 1746 r->ru_nvcsw += t->nvcsw; 1747 r->ru_nivcsw += t->nivcsw; 1748 r->ru_minflt += t->min_flt; 1749 r->ru_majflt += t->maj_flt; 1750 r->ru_inblock += task_io_get_inblock(t); 1751 r->ru_oublock += task_io_get_oublock(t); 1752 } 1753 1754 void getrusage(struct task_struct *p, int who, struct rusage *r) 1755 { 1756 struct task_struct *t; 1757 unsigned long flags; 1758 u64 tgutime, tgstime, utime, stime; 1759 unsigned long maxrss = 0; 1760 1761 memset((char *)r, 0, sizeof (*r)); 1762 utime = stime = 0; 1763 1764 if (who == RUSAGE_THREAD) { 1765 task_cputime_adjusted(current, &utime, &stime); 1766 accumulate_thread_rusage(p, r); 1767 maxrss = p->signal->maxrss; 1768 goto out; 1769 } 1770 1771 if (!lock_task_sighand(p, &flags)) 1772 return; 1773 1774 switch (who) { 1775 case RUSAGE_BOTH: 1776 case RUSAGE_CHILDREN: 1777 utime = p->signal->cutime; 1778 stime = p->signal->cstime; 1779 r->ru_nvcsw = p->signal->cnvcsw; 1780 r->ru_nivcsw = p->signal->cnivcsw; 1781 r->ru_minflt = p->signal->cmin_flt; 1782 r->ru_majflt = p->signal->cmaj_flt; 1783 r->ru_inblock = p->signal->cinblock; 1784 r->ru_oublock = p->signal->coublock; 1785 maxrss = p->signal->cmaxrss; 1786 1787 if (who == RUSAGE_CHILDREN) 1788 break; 1789 fallthrough; 1790 1791 case RUSAGE_SELF: 1792 thread_group_cputime_adjusted(p, &tgutime, &tgstime); 1793 utime += tgutime; 1794 stime += tgstime; 1795 r->ru_nvcsw += p->signal->nvcsw; 1796 r->ru_nivcsw += p->signal->nivcsw; 1797 r->ru_minflt += p->signal->min_flt; 1798 r->ru_majflt += p->signal->maj_flt; 1799 r->ru_inblock += p->signal->inblock; 1800 r->ru_oublock += p->signal->oublock; 1801 if (maxrss < p->signal->maxrss) 1802 maxrss = p->signal->maxrss; 1803 t = p; 1804 do { 1805 accumulate_thread_rusage(t, r); 1806 } while_each_thread(p, t); 1807 break; 1808 1809 default: 1810 BUG(); 1811 } 1812 unlock_task_sighand(p, &flags); 1813 1814 out: 1815 r->ru_utime = ns_to_kernel_old_timeval(utime); 1816 r->ru_stime = ns_to_kernel_old_timeval(stime); 1817 1818 if (who != RUSAGE_CHILDREN) { 1819 struct mm_struct *mm = get_task_mm(p); 1820 1821 if (mm) { 1822 setmax_mm_hiwater_rss(&maxrss, mm); 1823 mmput(mm); 1824 } 1825 } 1826 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ 1827 } 1828 1829 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) 1830 { 1831 struct rusage r; 1832 1833 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1834 who != RUSAGE_THREAD) 1835 return -EINVAL; 1836 1837 getrusage(current, who, &r); 1838 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; 1839 } 1840 1841 #ifdef CONFIG_COMPAT 1842 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) 1843 { 1844 struct rusage r; 1845 1846 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && 1847 who != RUSAGE_THREAD) 1848 return -EINVAL; 1849 1850 getrusage(current, who, &r); 1851 return put_compat_rusage(&r, ru); 1852 } 1853 #endif 1854 1855 SYSCALL_DEFINE1(umask, int, mask) 1856 { 1857 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); 1858 return mask; 1859 } 1860 1861 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) 1862 { 1863 struct fd exe; 1864 struct inode *inode; 1865 int err; 1866 1867 exe = fdget(fd); 1868 if (!exe.file) 1869 return -EBADF; 1870 1871 inode = file_inode(exe.file); 1872 1873 /* 1874 * Because the original mm->exe_file points to executable file, make 1875 * sure that this one is executable as well, to avoid breaking an 1876 * overall picture. 1877 */ 1878 err = -EACCES; 1879 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path)) 1880 goto exit; 1881 1882 err = file_permission(exe.file, MAY_EXEC); 1883 if (err) 1884 goto exit; 1885 1886 err = replace_mm_exe_file(mm, exe.file); 1887 exit: 1888 fdput(exe); 1889 return err; 1890 } 1891 1892 /* 1893 * Check arithmetic relations of passed addresses. 1894 * 1895 * WARNING: we don't require any capability here so be very careful 1896 * in what is allowed for modification from userspace. 1897 */ 1898 static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map) 1899 { 1900 unsigned long mmap_max_addr = TASK_SIZE; 1901 int error = -EINVAL, i; 1902 1903 static const unsigned char offsets[] = { 1904 offsetof(struct prctl_mm_map, start_code), 1905 offsetof(struct prctl_mm_map, end_code), 1906 offsetof(struct prctl_mm_map, start_data), 1907 offsetof(struct prctl_mm_map, end_data), 1908 offsetof(struct prctl_mm_map, start_brk), 1909 offsetof(struct prctl_mm_map, brk), 1910 offsetof(struct prctl_mm_map, start_stack), 1911 offsetof(struct prctl_mm_map, arg_start), 1912 offsetof(struct prctl_mm_map, arg_end), 1913 offsetof(struct prctl_mm_map, env_start), 1914 offsetof(struct prctl_mm_map, env_end), 1915 }; 1916 1917 /* 1918 * Make sure the members are not somewhere outside 1919 * of allowed address space. 1920 */ 1921 for (i = 0; i < ARRAY_SIZE(offsets); i++) { 1922 u64 val = *(u64 *)((char *)prctl_map + offsets[i]); 1923 1924 if ((unsigned long)val >= mmap_max_addr || 1925 (unsigned long)val < mmap_min_addr) 1926 goto out; 1927 } 1928 1929 /* 1930 * Make sure the pairs are ordered. 1931 */ 1932 #define __prctl_check_order(__m1, __op, __m2) \ 1933 ((unsigned long)prctl_map->__m1 __op \ 1934 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL 1935 error = __prctl_check_order(start_code, <, end_code); 1936 error |= __prctl_check_order(start_data,<=, end_data); 1937 error |= __prctl_check_order(start_brk, <=, brk); 1938 error |= __prctl_check_order(arg_start, <=, arg_end); 1939 error |= __prctl_check_order(env_start, <=, env_end); 1940 if (error) 1941 goto out; 1942 #undef __prctl_check_order 1943 1944 error = -EINVAL; 1945 1946 /* 1947 * Neither we should allow to override limits if they set. 1948 */ 1949 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk, 1950 prctl_map->start_brk, prctl_map->end_data, 1951 prctl_map->start_data)) 1952 goto out; 1953 1954 error = 0; 1955 out: 1956 return error; 1957 } 1958 1959 #ifdef CONFIG_CHECKPOINT_RESTORE 1960 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size) 1961 { 1962 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, }; 1963 unsigned long user_auxv[AT_VECTOR_SIZE]; 1964 struct mm_struct *mm = current->mm; 1965 int error; 1966 1967 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 1968 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256); 1969 1970 if (opt == PR_SET_MM_MAP_SIZE) 1971 return put_user((unsigned int)sizeof(prctl_map), 1972 (unsigned int __user *)addr); 1973 1974 if (data_size != sizeof(prctl_map)) 1975 return -EINVAL; 1976 1977 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map))) 1978 return -EFAULT; 1979 1980 error = validate_prctl_map_addr(&prctl_map); 1981 if (error) 1982 return error; 1983 1984 if (prctl_map.auxv_size) { 1985 /* 1986 * Someone is trying to cheat the auxv vector. 1987 */ 1988 if (!prctl_map.auxv || 1989 prctl_map.auxv_size > sizeof(mm->saved_auxv)) 1990 return -EINVAL; 1991 1992 memset(user_auxv, 0, sizeof(user_auxv)); 1993 if (copy_from_user(user_auxv, 1994 (const void __user *)prctl_map.auxv, 1995 prctl_map.auxv_size)) 1996 return -EFAULT; 1997 1998 /* Last entry must be AT_NULL as specification requires */ 1999 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL; 2000 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL; 2001 } 2002 2003 if (prctl_map.exe_fd != (u32)-1) { 2004 /* 2005 * Check if the current user is checkpoint/restore capable. 2006 * At the time of this writing, it checks for CAP_SYS_ADMIN 2007 * or CAP_CHECKPOINT_RESTORE. 2008 * Note that a user with access to ptrace can masquerade an 2009 * arbitrary program as any executable, even setuid ones. 2010 * This may have implications in the tomoyo subsystem. 2011 */ 2012 if (!checkpoint_restore_ns_capable(current_user_ns())) 2013 return -EPERM; 2014 2015 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd); 2016 if (error) 2017 return error; 2018 } 2019 2020 /* 2021 * arg_lock protects concurrent updates but we still need mmap_lock for 2022 * read to exclude races with sys_brk. 2023 */ 2024 mmap_read_lock(mm); 2025 2026 /* 2027 * We don't validate if these members are pointing to 2028 * real present VMAs because application may have correspond 2029 * VMAs already unmapped and kernel uses these members for statistics 2030 * output in procfs mostly, except 2031 * 2032 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups 2033 * for VMAs when updating these members so anything wrong written 2034 * here cause kernel to swear at userspace program but won't lead 2035 * to any problem in kernel itself 2036 */ 2037 2038 spin_lock(&mm->arg_lock); 2039 mm->start_code = prctl_map.start_code; 2040 mm->end_code = prctl_map.end_code; 2041 mm->start_data = prctl_map.start_data; 2042 mm->end_data = prctl_map.end_data; 2043 mm->start_brk = prctl_map.start_brk; 2044 mm->brk = prctl_map.brk; 2045 mm->start_stack = prctl_map.start_stack; 2046 mm->arg_start = prctl_map.arg_start; 2047 mm->arg_end = prctl_map.arg_end; 2048 mm->env_start = prctl_map.env_start; 2049 mm->env_end = prctl_map.env_end; 2050 spin_unlock(&mm->arg_lock); 2051 2052 /* 2053 * Note this update of @saved_auxv is lockless thus 2054 * if someone reads this member in procfs while we're 2055 * updating -- it may get partly updated results. It's 2056 * known and acceptable trade off: we leave it as is to 2057 * not introduce additional locks here making the kernel 2058 * more complex. 2059 */ 2060 if (prctl_map.auxv_size) 2061 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); 2062 2063 mmap_read_unlock(mm); 2064 return 0; 2065 } 2066 #endif /* CONFIG_CHECKPOINT_RESTORE */ 2067 2068 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr, 2069 unsigned long len) 2070 { 2071 /* 2072 * This doesn't move the auxiliary vector itself since it's pinned to 2073 * mm_struct, but it permits filling the vector with new values. It's 2074 * up to the caller to provide sane values here, otherwise userspace 2075 * tools which use this vector might be unhappy. 2076 */ 2077 unsigned long user_auxv[AT_VECTOR_SIZE] = {}; 2078 2079 if (len > sizeof(user_auxv)) 2080 return -EINVAL; 2081 2082 if (copy_from_user(user_auxv, (const void __user *)addr, len)) 2083 return -EFAULT; 2084 2085 /* Make sure the last entry is always AT_NULL */ 2086 user_auxv[AT_VECTOR_SIZE - 2] = 0; 2087 user_auxv[AT_VECTOR_SIZE - 1] = 0; 2088 2089 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); 2090 2091 task_lock(current); 2092 memcpy(mm->saved_auxv, user_auxv, len); 2093 task_unlock(current); 2094 2095 return 0; 2096 } 2097 2098 static int prctl_set_mm(int opt, unsigned long addr, 2099 unsigned long arg4, unsigned long arg5) 2100 { 2101 struct mm_struct *mm = current->mm; 2102 struct prctl_mm_map prctl_map = { 2103 .auxv = NULL, 2104 .auxv_size = 0, 2105 .exe_fd = -1, 2106 }; 2107 struct vm_area_struct *vma; 2108 int error; 2109 2110 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV && 2111 opt != PR_SET_MM_MAP && 2112 opt != PR_SET_MM_MAP_SIZE))) 2113 return -EINVAL; 2114 2115 #ifdef CONFIG_CHECKPOINT_RESTORE 2116 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE) 2117 return prctl_set_mm_map(opt, (const void __user *)addr, arg4); 2118 #endif 2119 2120 if (!capable(CAP_SYS_RESOURCE)) 2121 return -EPERM; 2122 2123 if (opt == PR_SET_MM_EXE_FILE) 2124 return prctl_set_mm_exe_file(mm, (unsigned int)addr); 2125 2126 if (opt == PR_SET_MM_AUXV) 2127 return prctl_set_auxv(mm, addr, arg4); 2128 2129 if (addr >= TASK_SIZE || addr < mmap_min_addr) 2130 return -EINVAL; 2131 2132 error = -EINVAL; 2133 2134 /* 2135 * arg_lock protects concurrent updates of arg boundaries, we need 2136 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr 2137 * validation. 2138 */ 2139 mmap_read_lock(mm); 2140 vma = find_vma(mm, addr); 2141 2142 spin_lock(&mm->arg_lock); 2143 prctl_map.start_code = mm->start_code; 2144 prctl_map.end_code = mm->end_code; 2145 prctl_map.start_data = mm->start_data; 2146 prctl_map.end_data = mm->end_data; 2147 prctl_map.start_brk = mm->start_brk; 2148 prctl_map.brk = mm->brk; 2149 prctl_map.start_stack = mm->start_stack; 2150 prctl_map.arg_start = mm->arg_start; 2151 prctl_map.arg_end = mm->arg_end; 2152 prctl_map.env_start = mm->env_start; 2153 prctl_map.env_end = mm->env_end; 2154 2155 switch (opt) { 2156 case PR_SET_MM_START_CODE: 2157 prctl_map.start_code = addr; 2158 break; 2159 case PR_SET_MM_END_CODE: 2160 prctl_map.end_code = addr; 2161 break; 2162 case PR_SET_MM_START_DATA: 2163 prctl_map.start_data = addr; 2164 break; 2165 case PR_SET_MM_END_DATA: 2166 prctl_map.end_data = addr; 2167 break; 2168 case PR_SET_MM_START_STACK: 2169 prctl_map.start_stack = addr; 2170 break; 2171 case PR_SET_MM_START_BRK: 2172 prctl_map.start_brk = addr; 2173 break; 2174 case PR_SET_MM_BRK: 2175 prctl_map.brk = addr; 2176 break; 2177 case PR_SET_MM_ARG_START: 2178 prctl_map.arg_start = addr; 2179 break; 2180 case PR_SET_MM_ARG_END: 2181 prctl_map.arg_end = addr; 2182 break; 2183 case PR_SET_MM_ENV_START: 2184 prctl_map.env_start = addr; 2185 break; 2186 case PR_SET_MM_ENV_END: 2187 prctl_map.env_end = addr; 2188 break; 2189 default: 2190 goto out; 2191 } 2192 2193 error = validate_prctl_map_addr(&prctl_map); 2194 if (error) 2195 goto out; 2196 2197 switch (opt) { 2198 /* 2199 * If command line arguments and environment 2200 * are placed somewhere else on stack, we can 2201 * set them up here, ARG_START/END to setup 2202 * command line arguments and ENV_START/END 2203 * for environment. 2204 */ 2205 case PR_SET_MM_START_STACK: 2206 case PR_SET_MM_ARG_START: 2207 case PR_SET_MM_ARG_END: 2208 case PR_SET_MM_ENV_START: 2209 case PR_SET_MM_ENV_END: 2210 if (!vma) { 2211 error = -EFAULT; 2212 goto out; 2213 } 2214 } 2215 2216 mm->start_code = prctl_map.start_code; 2217 mm->end_code = prctl_map.end_code; 2218 mm->start_data = prctl_map.start_data; 2219 mm->end_data = prctl_map.end_data; 2220 mm->start_brk = prctl_map.start_brk; 2221 mm->brk = prctl_map.brk; 2222 mm->start_stack = prctl_map.start_stack; 2223 mm->arg_start = prctl_map.arg_start; 2224 mm->arg_end = prctl_map.arg_end; 2225 mm->env_start = prctl_map.env_start; 2226 mm->env_end = prctl_map.env_end; 2227 2228 error = 0; 2229 out: 2230 spin_unlock(&mm->arg_lock); 2231 mmap_read_unlock(mm); 2232 return error; 2233 } 2234 2235 #ifdef CONFIG_CHECKPOINT_RESTORE 2236 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr) 2237 { 2238 return put_user(me->clear_child_tid, tid_addr); 2239 } 2240 #else 2241 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr) 2242 { 2243 return -EINVAL; 2244 } 2245 #endif 2246 2247 static int propagate_has_child_subreaper(struct task_struct *p, void *data) 2248 { 2249 /* 2250 * If task has has_child_subreaper - all its descendants 2251 * already have these flag too and new descendants will 2252 * inherit it on fork, skip them. 2253 * 2254 * If we've found child_reaper - skip descendants in 2255 * it's subtree as they will never get out pidns. 2256 */ 2257 if (p->signal->has_child_subreaper || 2258 is_child_reaper(task_pid(p))) 2259 return 0; 2260 2261 p->signal->has_child_subreaper = 1; 2262 return 1; 2263 } 2264 2265 int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which) 2266 { 2267 return -EINVAL; 2268 } 2269 2270 int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which, 2271 unsigned long ctrl) 2272 { 2273 return -EINVAL; 2274 } 2275 2276 #define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE) 2277 2278 #ifdef CONFIG_ANON_VMA_NAME 2279 2280 #define ANON_VMA_NAME_MAX_LEN 80 2281 #define ANON_VMA_NAME_INVALID_CHARS "\\`$[]" 2282 2283 static inline bool is_valid_name_char(char ch) 2284 { 2285 /* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */ 2286 return ch > 0x1f && ch < 0x7f && 2287 !strchr(ANON_VMA_NAME_INVALID_CHARS, ch); 2288 } 2289 2290 static int prctl_set_vma(unsigned long opt, unsigned long addr, 2291 unsigned long size, unsigned long arg) 2292 { 2293 struct mm_struct *mm = current->mm; 2294 const char __user *uname; 2295 struct anon_vma_name *anon_name = NULL; 2296 int error; 2297 2298 switch (opt) { 2299 case PR_SET_VMA_ANON_NAME: 2300 uname = (const char __user *)arg; 2301 if (uname) { 2302 char *name, *pch; 2303 2304 name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN); 2305 if (IS_ERR(name)) 2306 return PTR_ERR(name); 2307 2308 for (pch = name; *pch != '\0'; pch++) { 2309 if (!is_valid_name_char(*pch)) { 2310 kfree(name); 2311 return -EINVAL; 2312 } 2313 } 2314 /* anon_vma has its own copy */ 2315 anon_name = anon_vma_name_alloc(name); 2316 kfree(name); 2317 if (!anon_name) 2318 return -ENOMEM; 2319 2320 } 2321 2322 mmap_write_lock(mm); 2323 error = madvise_set_anon_name(mm, addr, size, anon_name); 2324 mmap_write_unlock(mm); 2325 anon_vma_name_put(anon_name); 2326 break; 2327 default: 2328 error = -EINVAL; 2329 } 2330 2331 return error; 2332 } 2333 2334 #else /* CONFIG_ANON_VMA_NAME */ 2335 static int prctl_set_vma(unsigned long opt, unsigned long start, 2336 unsigned long size, unsigned long arg) 2337 { 2338 return -EINVAL; 2339 } 2340 #endif /* CONFIG_ANON_VMA_NAME */ 2341 2342 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, 2343 unsigned long, arg4, unsigned long, arg5) 2344 { 2345 struct task_struct *me = current; 2346 unsigned char comm[sizeof(me->comm)]; 2347 long error; 2348 2349 error = security_task_prctl(option, arg2, arg3, arg4, arg5); 2350 if (error != -ENOSYS) 2351 return error; 2352 2353 error = 0; 2354 switch (option) { 2355 case PR_SET_PDEATHSIG: 2356 if (!valid_signal(arg2)) { 2357 error = -EINVAL; 2358 break; 2359 } 2360 me->pdeath_signal = arg2; 2361 break; 2362 case PR_GET_PDEATHSIG: 2363 error = put_user(me->pdeath_signal, (int __user *)arg2); 2364 break; 2365 case PR_GET_DUMPABLE: 2366 error = get_dumpable(me->mm); 2367 break; 2368 case PR_SET_DUMPABLE: 2369 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { 2370 error = -EINVAL; 2371 break; 2372 } 2373 set_dumpable(me->mm, arg2); 2374 break; 2375 2376 case PR_SET_UNALIGN: 2377 error = SET_UNALIGN_CTL(me, arg2); 2378 break; 2379 case PR_GET_UNALIGN: 2380 error = GET_UNALIGN_CTL(me, arg2); 2381 break; 2382 case PR_SET_FPEMU: 2383 error = SET_FPEMU_CTL(me, arg2); 2384 break; 2385 case PR_GET_FPEMU: 2386 error = GET_FPEMU_CTL(me, arg2); 2387 break; 2388 case PR_SET_FPEXC: 2389 error = SET_FPEXC_CTL(me, arg2); 2390 break; 2391 case PR_GET_FPEXC: 2392 error = GET_FPEXC_CTL(me, arg2); 2393 break; 2394 case PR_GET_TIMING: 2395 error = PR_TIMING_STATISTICAL; 2396 break; 2397 case PR_SET_TIMING: 2398 if (arg2 != PR_TIMING_STATISTICAL) 2399 error = -EINVAL; 2400 break; 2401 case PR_SET_NAME: 2402 comm[sizeof(me->comm) - 1] = 0; 2403 if (strncpy_from_user(comm, (char __user *)arg2, 2404 sizeof(me->comm) - 1) < 0) 2405 return -EFAULT; 2406 set_task_comm(me, comm); 2407 proc_comm_connector(me); 2408 break; 2409 case PR_GET_NAME: 2410 get_task_comm(comm, me); 2411 if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) 2412 return -EFAULT; 2413 break; 2414 case PR_GET_ENDIAN: 2415 error = GET_ENDIAN(me, arg2); 2416 break; 2417 case PR_SET_ENDIAN: 2418 error = SET_ENDIAN(me, arg2); 2419 break; 2420 case PR_GET_SECCOMP: 2421 error = prctl_get_seccomp(); 2422 break; 2423 case PR_SET_SECCOMP: 2424 error = prctl_set_seccomp(arg2, (char __user *)arg3); 2425 break; 2426 case PR_GET_TSC: 2427 error = GET_TSC_CTL(arg2); 2428 break; 2429 case PR_SET_TSC: 2430 error = SET_TSC_CTL(arg2); 2431 break; 2432 case PR_TASK_PERF_EVENTS_DISABLE: 2433 error = perf_event_task_disable(); 2434 break; 2435 case PR_TASK_PERF_EVENTS_ENABLE: 2436 error = perf_event_task_enable(); 2437 break; 2438 case PR_GET_TIMERSLACK: 2439 if (current->timer_slack_ns > ULONG_MAX) 2440 error = ULONG_MAX; 2441 else 2442 error = current->timer_slack_ns; 2443 break; 2444 case PR_SET_TIMERSLACK: 2445 if (arg2 <= 0) 2446 current->timer_slack_ns = 2447 current->default_timer_slack_ns; 2448 else 2449 current->timer_slack_ns = arg2; 2450 break; 2451 case PR_MCE_KILL: 2452 if (arg4 | arg5) 2453 return -EINVAL; 2454 switch (arg2) { 2455 case PR_MCE_KILL_CLEAR: 2456 if (arg3 != 0) 2457 return -EINVAL; 2458 current->flags &= ~PF_MCE_PROCESS; 2459 break; 2460 case PR_MCE_KILL_SET: 2461 current->flags |= PF_MCE_PROCESS; 2462 if (arg3 == PR_MCE_KILL_EARLY) 2463 current->flags |= PF_MCE_EARLY; 2464 else if (arg3 == PR_MCE_KILL_LATE) 2465 current->flags &= ~PF_MCE_EARLY; 2466 else if (arg3 == PR_MCE_KILL_DEFAULT) 2467 current->flags &= 2468 ~(PF_MCE_EARLY|PF_MCE_PROCESS); 2469 else 2470 return -EINVAL; 2471 break; 2472 default: 2473 return -EINVAL; 2474 } 2475 break; 2476 case PR_MCE_KILL_GET: 2477 if (arg2 | arg3 | arg4 | arg5) 2478 return -EINVAL; 2479 if (current->flags & PF_MCE_PROCESS) 2480 error = (current->flags & PF_MCE_EARLY) ? 2481 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; 2482 else 2483 error = PR_MCE_KILL_DEFAULT; 2484 break; 2485 case PR_SET_MM: 2486 error = prctl_set_mm(arg2, arg3, arg4, arg5); 2487 break; 2488 case PR_GET_TID_ADDRESS: 2489 error = prctl_get_tid_address(me, (int __user * __user *)arg2); 2490 break; 2491 case PR_SET_CHILD_SUBREAPER: 2492 me->signal->is_child_subreaper = !!arg2; 2493 if (!arg2) 2494 break; 2495 2496 walk_process_tree(me, propagate_has_child_subreaper, NULL); 2497 break; 2498 case PR_GET_CHILD_SUBREAPER: 2499 error = put_user(me->signal->is_child_subreaper, 2500 (int __user *)arg2); 2501 break; 2502 case PR_SET_NO_NEW_PRIVS: 2503 if (arg2 != 1 || arg3 || arg4 || arg5) 2504 return -EINVAL; 2505 2506 task_set_no_new_privs(current); 2507 break; 2508 case PR_GET_NO_NEW_PRIVS: 2509 if (arg2 || arg3 || arg4 || arg5) 2510 return -EINVAL; 2511 return task_no_new_privs(current) ? 1 : 0; 2512 case PR_GET_THP_DISABLE: 2513 if (arg2 || arg3 || arg4 || arg5) 2514 return -EINVAL; 2515 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags); 2516 break; 2517 case PR_SET_THP_DISABLE: 2518 if (arg3 || arg4 || arg5) 2519 return -EINVAL; 2520 if (mmap_write_lock_killable(me->mm)) 2521 return -EINTR; 2522 if (arg2) 2523 set_bit(MMF_DISABLE_THP, &me->mm->flags); 2524 else 2525 clear_bit(MMF_DISABLE_THP, &me->mm->flags); 2526 mmap_write_unlock(me->mm); 2527 break; 2528 case PR_MPX_ENABLE_MANAGEMENT: 2529 case PR_MPX_DISABLE_MANAGEMENT: 2530 /* No longer implemented: */ 2531 return -EINVAL; 2532 case PR_SET_FP_MODE: 2533 error = SET_FP_MODE(me, arg2); 2534 break; 2535 case PR_GET_FP_MODE: 2536 error = GET_FP_MODE(me); 2537 break; 2538 case PR_SVE_SET_VL: 2539 error = SVE_SET_VL(arg2); 2540 break; 2541 case PR_SVE_GET_VL: 2542 error = SVE_GET_VL(); 2543 break; 2544 case PR_GET_SPECULATION_CTRL: 2545 if (arg3 || arg4 || arg5) 2546 return -EINVAL; 2547 error = arch_prctl_spec_ctrl_get(me, arg2); 2548 break; 2549 case PR_SET_SPECULATION_CTRL: 2550 if (arg4 || arg5) 2551 return -EINVAL; 2552 error = arch_prctl_spec_ctrl_set(me, arg2, arg3); 2553 break; 2554 case PR_PAC_RESET_KEYS: 2555 if (arg3 || arg4 || arg5) 2556 return -EINVAL; 2557 error = PAC_RESET_KEYS(me, arg2); 2558 break; 2559 case PR_PAC_SET_ENABLED_KEYS: 2560 if (arg4 || arg5) 2561 return -EINVAL; 2562 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3); 2563 break; 2564 case PR_PAC_GET_ENABLED_KEYS: 2565 if (arg2 || arg3 || arg4 || arg5) 2566 return -EINVAL; 2567 error = PAC_GET_ENABLED_KEYS(me); 2568 break; 2569 case PR_SET_TAGGED_ADDR_CTRL: 2570 if (arg3 || arg4 || arg5) 2571 return -EINVAL; 2572 error = SET_TAGGED_ADDR_CTRL(arg2); 2573 break; 2574 case PR_GET_TAGGED_ADDR_CTRL: 2575 if (arg2 || arg3 || arg4 || arg5) 2576 return -EINVAL; 2577 error = GET_TAGGED_ADDR_CTRL(); 2578 break; 2579 case PR_SET_IO_FLUSHER: 2580 if (!capable(CAP_SYS_RESOURCE)) 2581 return -EPERM; 2582 2583 if (arg3 || arg4 || arg5) 2584 return -EINVAL; 2585 2586 if (arg2 == 1) 2587 current->flags |= PR_IO_FLUSHER; 2588 else if (!arg2) 2589 current->flags &= ~PR_IO_FLUSHER; 2590 else 2591 return -EINVAL; 2592 break; 2593 case PR_GET_IO_FLUSHER: 2594 if (!capable(CAP_SYS_RESOURCE)) 2595 return -EPERM; 2596 2597 if (arg2 || arg3 || arg4 || arg5) 2598 return -EINVAL; 2599 2600 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER; 2601 break; 2602 case PR_SET_SYSCALL_USER_DISPATCH: 2603 error = set_syscall_user_dispatch(arg2, arg3, arg4, 2604 (char __user *) arg5); 2605 break; 2606 #ifdef CONFIG_SCHED_CORE 2607 case PR_SCHED_CORE: 2608 error = sched_core_share_pid(arg2, arg3, arg4, arg5); 2609 break; 2610 #endif 2611 case PR_SET_VMA: 2612 error = prctl_set_vma(arg2, arg3, arg4, arg5); 2613 break; 2614 default: 2615 error = -EINVAL; 2616 break; 2617 } 2618 return error; 2619 } 2620 2621 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, 2622 struct getcpu_cache __user *, unused) 2623 { 2624 int err = 0; 2625 int cpu = raw_smp_processor_id(); 2626 2627 if (cpup) 2628 err |= put_user(cpu, cpup); 2629 if (nodep) 2630 err |= put_user(cpu_to_node(cpu), nodep); 2631 return err ? -EFAULT : 0; 2632 } 2633 2634 /** 2635 * do_sysinfo - fill in sysinfo struct 2636 * @info: pointer to buffer to fill 2637 */ 2638 static int do_sysinfo(struct sysinfo *info) 2639 { 2640 unsigned long mem_total, sav_total; 2641 unsigned int mem_unit, bitcount; 2642 struct timespec64 tp; 2643 2644 memset(info, 0, sizeof(struct sysinfo)); 2645 2646 ktime_get_boottime_ts64(&tp); 2647 timens_add_boottime(&tp); 2648 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); 2649 2650 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); 2651 2652 info->procs = nr_threads; 2653 2654 si_meminfo(info); 2655 si_swapinfo(info); 2656 2657 /* 2658 * If the sum of all the available memory (i.e. ram + swap) 2659 * is less than can be stored in a 32 bit unsigned long then 2660 * we can be binary compatible with 2.2.x kernels. If not, 2661 * well, in that case 2.2.x was broken anyways... 2662 * 2663 * -Erik Andersen <andersee@debian.org> 2664 */ 2665 2666 mem_total = info->totalram + info->totalswap; 2667 if (mem_total < info->totalram || mem_total < info->totalswap) 2668 goto out; 2669 bitcount = 0; 2670 mem_unit = info->mem_unit; 2671 while (mem_unit > 1) { 2672 bitcount++; 2673 mem_unit >>= 1; 2674 sav_total = mem_total; 2675 mem_total <<= 1; 2676 if (mem_total < sav_total) 2677 goto out; 2678 } 2679 2680 /* 2681 * If mem_total did not overflow, multiply all memory values by 2682 * info->mem_unit and set it to 1. This leaves things compatible 2683 * with 2.2.x, and also retains compatibility with earlier 2.4.x 2684 * kernels... 2685 */ 2686 2687 info->mem_unit = 1; 2688 info->totalram <<= bitcount; 2689 info->freeram <<= bitcount; 2690 info->sharedram <<= bitcount; 2691 info->bufferram <<= bitcount; 2692 info->totalswap <<= bitcount; 2693 info->freeswap <<= bitcount; 2694 info->totalhigh <<= bitcount; 2695 info->freehigh <<= bitcount; 2696 2697 out: 2698 return 0; 2699 } 2700 2701 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) 2702 { 2703 struct sysinfo val; 2704 2705 do_sysinfo(&val); 2706 2707 if (copy_to_user(info, &val, sizeof(struct sysinfo))) 2708 return -EFAULT; 2709 2710 return 0; 2711 } 2712 2713 #ifdef CONFIG_COMPAT 2714 struct compat_sysinfo { 2715 s32 uptime; 2716 u32 loads[3]; 2717 u32 totalram; 2718 u32 freeram; 2719 u32 sharedram; 2720 u32 bufferram; 2721 u32 totalswap; 2722 u32 freeswap; 2723 u16 procs; 2724 u16 pad; 2725 u32 totalhigh; 2726 u32 freehigh; 2727 u32 mem_unit; 2728 char _f[20-2*sizeof(u32)-sizeof(int)]; 2729 }; 2730 2731 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) 2732 { 2733 struct sysinfo s; 2734 struct compat_sysinfo s_32; 2735 2736 do_sysinfo(&s); 2737 2738 /* Check to see if any memory value is too large for 32-bit and scale 2739 * down if needed 2740 */ 2741 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) { 2742 int bitcount = 0; 2743 2744 while (s.mem_unit < PAGE_SIZE) { 2745 s.mem_unit <<= 1; 2746 bitcount++; 2747 } 2748 2749 s.totalram >>= bitcount; 2750 s.freeram >>= bitcount; 2751 s.sharedram >>= bitcount; 2752 s.bufferram >>= bitcount; 2753 s.totalswap >>= bitcount; 2754 s.freeswap >>= bitcount; 2755 s.totalhigh >>= bitcount; 2756 s.freehigh >>= bitcount; 2757 } 2758 2759 memset(&s_32, 0, sizeof(s_32)); 2760 s_32.uptime = s.uptime; 2761 s_32.loads[0] = s.loads[0]; 2762 s_32.loads[1] = s.loads[1]; 2763 s_32.loads[2] = s.loads[2]; 2764 s_32.totalram = s.totalram; 2765 s_32.freeram = s.freeram; 2766 s_32.sharedram = s.sharedram; 2767 s_32.bufferram = s.bufferram; 2768 s_32.totalswap = s.totalswap; 2769 s_32.freeswap = s.freeswap; 2770 s_32.procs = s.procs; 2771 s_32.totalhigh = s.totalhigh; 2772 s_32.freehigh = s.freehigh; 2773 s_32.mem_unit = s.mem_unit; 2774 if (copy_to_user(info, &s_32, sizeof(s_32))) 2775 return -EFAULT; 2776 return 0; 2777 } 2778 #endif /* CONFIG_COMPAT */ 2779