projects/linux·blob v5.17-rc6 · refs

2768 lines · 64.5 KiB

1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/kernel/sys.c
4 *
5 * Copyright (C) 1991, 1992 Linus Torvalds
6 */
7
8#include <linux/export.h>
9#include <linux/mm.h>
10#include <linux/utsname.h>
11#include <linux/mman.h>
12#include <linux/reboot.h>
13#include <linux/prctl.h>
14#include <linux/highuid.h>
15#include <linux/fs.h>
16#include <linux/kmod.h>
17#include <linux/perf_event.h>
18#include <linux/resource.h>
19#include <linux/kernel.h>
20#include <linux/workqueue.h>
21#include <linux/capability.h>
22#include <linux/device.h>
23#include <linux/key.h>
24#include <linux/times.h>
25#include <linux/posix-timers.h>
26#include <linux/security.h>
27#include <linux/suspend.h>
28#include <linux/tty.h>
29#include <linux/signal.h>
30#include <linux/cn_proc.h>
31#include <linux/getcpu.h>
32#include <linux/task_io_accounting_ops.h>
33#include <linux/seccomp.h>
34#include <linux/cpu.h>
35#include <linux/personality.h>
36#include <linux/ptrace.h>
37#include <linux/fs_struct.h>
38#include <linux/file.h>
39#include <linux/mount.h>
40#include <linux/gfp.h>
41#include <linux/syscore_ops.h>
42#include <linux/version.h>
43#include <linux/ctype.h>
44#include <linux/syscall_user_dispatch.h>
45
46#include <linux/compat.h>
47#include <linux/syscalls.h>
48#include <linux/kprobes.h>
49#include <linux/user_namespace.h>
50#include <linux/time_namespace.h>
51#include <linux/binfmts.h>
52
53#include <linux/sched.h>
54#include <linux/sched/autogroup.h>
55#include <linux/sched/loadavg.h>
56#include <linux/sched/stat.h>
57#include <linux/sched/mm.h>
58#include <linux/sched/coredump.h>
59#include <linux/sched/task.h>
60#include <linux/sched/cputime.h>
61#include <linux/rcupdate.h>
62#include <linux/uidgid.h>
63#include <linux/cred.h>
64
65#include <linux/nospec.h>
66
67#include <linux/kmsg_dump.h>
68/* Move somewhere else to avoid recompiling? */
69#include <generated/utsrelease.h>
70
71#include <linux/uaccess.h>
72#include <asm/io.h>
73#include <asm/unistd.h>
74
75#include "uid16.h"
76
77#ifndef SET_UNALIGN_CTL
78# define SET_UNALIGN_CTL(a, b) (-EINVAL)
79#endif
80#ifndef GET_UNALIGN_CTL
81# define GET_UNALIGN_CTL(a, b) (-EINVAL)
82#endif
83#ifndef SET_FPEMU_CTL
84# define SET_FPEMU_CTL(a, b) (-EINVAL)
85#endif
86#ifndef GET_FPEMU_CTL
87# define GET_FPEMU_CTL(a, b) (-EINVAL)
88#endif
89#ifndef SET_FPEXC_CTL
90# define SET_FPEXC_CTL(a, b) (-EINVAL)
91#endif
92#ifndef GET_FPEXC_CTL
93# define GET_FPEXC_CTL(a, b) (-EINVAL)
94#endif
95#ifndef GET_ENDIAN
96# define GET_ENDIAN(a, b) (-EINVAL)
97#endif
98#ifndef SET_ENDIAN
99# define SET_ENDIAN(a, b) (-EINVAL)
100#endif
101#ifndef GET_TSC_CTL
102# define GET_TSC_CTL(a) (-EINVAL)
103#endif
104#ifndef SET_TSC_CTL
105# define SET_TSC_CTL(a) (-EINVAL)
106#endif
107#ifndef GET_FP_MODE
108# define GET_FP_MODE(a) (-EINVAL)
109#endif
110#ifndef SET_FP_MODE
111# define SET_FP_MODE(a,b) (-EINVAL)
112#endif
113#ifndef SVE_SET_VL
114# define SVE_SET_VL(a) (-EINVAL)
115#endif
116#ifndef SVE_GET_VL
117# define SVE_GET_VL() (-EINVAL)
118#endif
119#ifndef PAC_RESET_KEYS
120# define PAC_RESET_KEYS(a, b) (-EINVAL)
121#endif
122#ifndef PAC_SET_ENABLED_KEYS
123# define PAC_SET_ENABLED_KEYS(a, b, c) (-EINVAL)
124#endif
125#ifndef PAC_GET_ENABLED_KEYS
126# define PAC_GET_ENABLED_KEYS(a) (-EINVAL)
127#endif
128#ifndef SET_TAGGED_ADDR_CTRL
129# define SET_TAGGED_ADDR_CTRL(a) (-EINVAL)
130#endif
131#ifndef GET_TAGGED_ADDR_CTRL
132# define GET_TAGGED_ADDR_CTRL() (-EINVAL)
133#endif
134
135/*
136 * this is where the system-wide overflow UID and GID are defined, for
137 * architectures that now have 32-bit UID/GID but didn't in the past
138 */
139
140int overflowuid = DEFAULT_OVERFLOWUID;
141int overflowgid = DEFAULT_OVERFLOWGID;
142
143EXPORT_SYMBOL(overflowuid);
144EXPORT_SYMBOL(overflowgid);
145
146/*
147 * the same as above, but for filesystems which can only store a 16-bit
148 * UID and GID. as such, this is needed on all architectures
149 */
150
151int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
152int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
153
154EXPORT_SYMBOL(fs_overflowuid);
155EXPORT_SYMBOL(fs_overflowgid);
156
157/*
158 * Returns true if current's euid is same as p's uid or euid,
159 * or has CAP_SYS_NICE to p's user_ns.
160 *
161 * Called with rcu_read_lock, creds are safe
162 */
163static bool set_one_prio_perm(struct task_struct *p)
164{
165 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
166
167 if (uid_eq(pcred->uid, cred->euid) ||
168 uid_eq(pcred->euid, cred->euid))
169 return true;
170 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
171 return true;
172 return false;
173}
174
175/*
176 * set the priority of a task
177 * - the caller must hold the RCU read lock
178 */
179static int set_one_prio(struct task_struct *p, int niceval, int error)
180{
181 int no_nice;
182
183 if (!set_one_prio_perm(p)) {
184 error = -EPERM;
185 goto out;
186 }
187 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
188 error = -EACCES;
189 goto out;
190 }
191 no_nice = security_task_setnice(p, niceval);
192 if (no_nice) {
193 error = no_nice;
194 goto out;
195 }
196 if (error == -ESRCH)
197 error = 0;
198 set_user_nice(p, niceval);
199out:
200 return error;
201}
202
203SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
204{
205 struct task_struct *g, *p;
206 struct user_struct *user;
207 const struct cred *cred = current_cred();
208 int error = -EINVAL;
209 struct pid *pgrp;
210 kuid_t uid;
211
212 if (which > PRIO_USER || which < PRIO_PROCESS)
213 goto out;
214
215 /* normalize: avoid signed division (rounding problems) */
216 error = -ESRCH;
217 if (niceval < MIN_NICE)
218 niceval = MIN_NICE;
219 if (niceval > MAX_NICE)
220 niceval = MAX_NICE;
221
222 rcu_read_lock();
223 switch (which) {
224 case PRIO_PROCESS:
225 if (who)
226 p = find_task_by_vpid(who);
227 else
228 p = current;
229 if (p)
230 error = set_one_prio(p, niceval, error);
231 break;
232 case PRIO_PGRP:
233 if (who)
234 pgrp = find_vpid(who);
235 else
236 pgrp = task_pgrp(current);
237 read_lock(&tasklist_lock);
238 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
239 error = set_one_prio(p, niceval, error);
240 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
241 read_unlock(&tasklist_lock);
242 break;
243 case PRIO_USER:
244 uid = make_kuid(cred->user_ns, who);
245 user = cred->user;
246 if (!who)
247 uid = cred->uid;
248 else if (!uid_eq(uid, cred->uid)) {
249 user = find_user(uid);
250 if (!user)
251 goto out_unlock; /* No processes for this user */
252 }
253 for_each_process_thread(g, p) {
254 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
255 error = set_one_prio(p, niceval, error);
256 }
257 if (!uid_eq(uid, cred->uid))
258 free_uid(user); /* For find_user() */
259 break;
260 }
261out_unlock:
262 rcu_read_unlock();
263out:
264 return error;
265}
266
267/*
268 * Ugh. To avoid negative return values, "getpriority()" will
269 * not return the normal nice-value, but a negated value that
270 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
271 * to stay compatible.
272 */
273SYSCALL_DEFINE2(getpriority, int, which, int, who)
274{
275 struct task_struct *g, *p;
276 struct user_struct *user;
277 const struct cred *cred = current_cred();
278 long niceval, retval = -ESRCH;
279 struct pid *pgrp;
280 kuid_t uid;
281
282 if (which > PRIO_USER || which < PRIO_PROCESS)
283 return -EINVAL;
284
285 rcu_read_lock();
286 switch (which) {
287 case PRIO_PROCESS:
288 if (who)
289 p = find_task_by_vpid(who);
290 else
291 p = current;
292 if (p) {
293 niceval = nice_to_rlimit(task_nice(p));
294 if (niceval > retval)
295 retval = niceval;
296 }
297 break;
298 case PRIO_PGRP:
299 if (who)
300 pgrp = find_vpid(who);
301 else
302 pgrp = task_pgrp(current);
303 read_lock(&tasklist_lock);
304 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
305 niceval = nice_to_rlimit(task_nice(p));
306 if (niceval > retval)
307 retval = niceval;
308 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
309 read_unlock(&tasklist_lock);
310 break;
311 case PRIO_USER:
312 uid = make_kuid(cred->user_ns, who);
313 user = cred->user;
314 if (!who)
315 uid = cred->uid;
316 else if (!uid_eq(uid, cred->uid)) {
317 user = find_user(uid);
318 if (!user)
319 goto out_unlock; /* No processes for this user */
320 }
321 for_each_process_thread(g, p) {
322 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
323 niceval = nice_to_rlimit(task_nice(p));
324 if (niceval > retval)
325 retval = niceval;
326 }
327 }
328 if (!uid_eq(uid, cred->uid))
329 free_uid(user); /* for find_user() */
330 break;
331 }
332out_unlock:
333 rcu_read_unlock();
334
335 return retval;
336}
337
338/*
339 * Unprivileged users may change the real gid to the effective gid
340 * or vice versa. (BSD-style)
341 *
342 * If you set the real gid at all, or set the effective gid to a value not
343 * equal to the real gid, then the saved gid is set to the new effective gid.
344 *
345 * This makes it possible for a setgid program to completely drop its
346 * privileges, which is often a useful assertion to make when you are doing
347 * a security audit over a program.
348 *
349 * The general idea is that a program which uses just setregid() will be
350 * 100% compatible with BSD. A program which uses just setgid() will be
351 * 100% compatible with POSIX with saved IDs.
352 *
353 * SMP: There are not races, the GIDs are checked only by filesystem
354 * operations (as far as semantic preservation is concerned).
355 */
356#ifdef CONFIG_MULTIUSER
357long __sys_setregid(gid_t rgid, gid_t egid)
358{
359 struct user_namespace *ns = current_user_ns();
360 const struct cred *old;
361 struct cred *new;
362 int retval;
363 kgid_t krgid, kegid;
364
365 krgid = make_kgid(ns, rgid);
366 kegid = make_kgid(ns, egid);
367
368 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
369 return -EINVAL;
370 if ((egid != (gid_t) -1) && !gid_valid(kegid))
371 return -EINVAL;
372
373 new = prepare_creds();
374 if (!new)
375 return -ENOMEM;
376 old = current_cred();
377
378 retval = -EPERM;
379 if (rgid != (gid_t) -1) {
380 if (gid_eq(old->gid, krgid) ||
381 gid_eq(old->egid, krgid) ||
382 ns_capable_setid(old->user_ns, CAP_SETGID))
383 new->gid = krgid;
384 else
385 goto error;
386 }
387 if (egid != (gid_t) -1) {
388 if (gid_eq(old->gid, kegid) ||
389 gid_eq(old->egid, kegid) ||
390 gid_eq(old->sgid, kegid) ||
391 ns_capable_setid(old->user_ns, CAP_SETGID))
392 new->egid = kegid;
393 else
394 goto error;
395 }
396
397 if (rgid != (gid_t) -1 ||
398 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
399 new->sgid = new->egid;
400 new->fsgid = new->egid;
401
402 retval = security_task_fix_setgid(new, old, LSM_SETID_RE);
403 if (retval < 0)
404 goto error;
405
406 return commit_creds(new);
407
408error:
409 abort_creds(new);
410 return retval;
411}
412
413SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
414{
415 return __sys_setregid(rgid, egid);
416}
417
418/*
419 * setgid() is implemented like SysV w/ SAVED_IDS
420 *
421 * SMP: Same implicit races as above.
422 */
423long __sys_setgid(gid_t gid)
424{
425 struct user_namespace *ns = current_user_ns();
426 const struct cred *old;
427 struct cred *new;
428 int retval;
429 kgid_t kgid;
430
431 kgid = make_kgid(ns, gid);
432 if (!gid_valid(kgid))
433 return -EINVAL;
434
435 new = prepare_creds();
436 if (!new)
437 return -ENOMEM;
438 old = current_cred();
439
440 retval = -EPERM;
441 if (ns_capable_setid(old->user_ns, CAP_SETGID))
442 new->gid = new->egid = new->sgid = new->fsgid = kgid;
443 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
444 new->egid = new->fsgid = kgid;
445 else
446 goto error;
447
448 retval = security_task_fix_setgid(new, old, LSM_SETID_ID);
449 if (retval < 0)
450 goto error;
451
452 return commit_creds(new);
453
454error:
455 abort_creds(new);
456 return retval;
457}
458
459SYSCALL_DEFINE1(setgid, gid_t, gid)
460{
461 return __sys_setgid(gid);
462}
463
464/*
465 * change the user struct in a credentials set to match the new UID
466 */
467static int set_user(struct cred *new)
468{
469 struct user_struct *new_user;
470
471 new_user = alloc_uid(new->uid);
472 if (!new_user)
473 return -EAGAIN;
474
475 free_uid(new->user);
476 new->user = new_user;
477 return 0;
478}
479
480static void flag_nproc_exceeded(struct cred *new)
481{
482 if (new->ucounts == current_ucounts())
483 return;
484
485 /*
486 * We don't fail in case of NPROC limit excess here because too many
487 * poorly written programs don't check set*uid() return code, assuming
488 * it never fails if called by root. We may still enforce NPROC limit
489 * for programs doing set*uid()+execve() by harmlessly deferring the
490 * failure to the execve() stage.
491 */
492 if (is_ucounts_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) &&
493 new->user != INIT_USER)
494 current->flags |= PF_NPROC_EXCEEDED;
495 else
496 current->flags &= ~PF_NPROC_EXCEEDED;
497}
498
499/*
500 * Unprivileged users may change the real uid to the effective uid
501 * or vice versa. (BSD-style)
502 *
503 * If you set the real uid at all, or set the effective uid to a value not
504 * equal to the real uid, then the saved uid is set to the new effective uid.
505 *
506 * This makes it possible for a setuid program to completely drop its
507 * privileges, which is often a useful assertion to make when you are doing
508 * a security audit over a program.
509 *
510 * The general idea is that a program which uses just setreuid() will be
511 * 100% compatible with BSD. A program which uses just setuid() will be
512 * 100% compatible with POSIX with saved IDs.
513 */
514long __sys_setreuid(uid_t ruid, uid_t euid)
515{
516 struct user_namespace *ns = current_user_ns();
517 const struct cred *old;
518 struct cred *new;
519 int retval;
520 kuid_t kruid, keuid;
521
522 kruid = make_kuid(ns, ruid);
523 keuid = make_kuid(ns, euid);
524
525 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
526 return -EINVAL;
527 if ((euid != (uid_t) -1) && !uid_valid(keuid))
528 return -EINVAL;
529
530 new = prepare_creds();
531 if (!new)
532 return -ENOMEM;
533 old = current_cred();
534
535 retval = -EPERM;
536 if (ruid != (uid_t) -1) {
537 new->uid = kruid;
538 if (!uid_eq(old->uid, kruid) &&
539 !uid_eq(old->euid, kruid) &&
540 !ns_capable_setid(old->user_ns, CAP_SETUID))
541 goto error;
542 }
543
544 if (euid != (uid_t) -1) {
545 new->euid = keuid;
546 if (!uid_eq(old->uid, keuid) &&
547 !uid_eq(old->euid, keuid) &&
548 !uid_eq(old->suid, keuid) &&
549 !ns_capable_setid(old->user_ns, CAP_SETUID))
550 goto error;
551 }
552
553 if (!uid_eq(new->uid, old->uid)) {
554 retval = set_user(new);
555 if (retval < 0)
556 goto error;
557 }
558 if (ruid != (uid_t) -1 ||
559 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
560 new->suid = new->euid;
561 new->fsuid = new->euid;
562
563 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
564 if (retval < 0)
565 goto error;
566
567 retval = set_cred_ucounts(new);
568 if (retval < 0)
569 goto error;
570
571 flag_nproc_exceeded(new);
572 return commit_creds(new);
573
574error:
575 abort_creds(new);
576 return retval;
577}
578
579SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
580{
581 return __sys_setreuid(ruid, euid);
582}
583
584/*
585 * setuid() is implemented like SysV with SAVED_IDS
586 *
587 * Note that SAVED_ID's is deficient in that a setuid root program
588 * like sendmail, for example, cannot set its uid to be a normal
589 * user and then switch back, because if you're root, setuid() sets
590 * the saved uid too. If you don't like this, blame the bright people
591 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
592 * will allow a root program to temporarily drop privileges and be able to
593 * regain them by swapping the real and effective uid.
594 */
595long __sys_setuid(uid_t uid)
596{
597 struct user_namespace *ns = current_user_ns();
598 const struct cred *old;
599 struct cred *new;
600 int retval;
601 kuid_t kuid;
602
603 kuid = make_kuid(ns, uid);
604 if (!uid_valid(kuid))
605 return -EINVAL;
606
607 new = prepare_creds();
608 if (!new)
609 return -ENOMEM;
610 old = current_cred();
611
612 retval = -EPERM;
613 if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
614 new->suid = new->uid = kuid;
615 if (!uid_eq(kuid, old->uid)) {
616 retval = set_user(new);
617 if (retval < 0)
618 goto error;
619 }
620 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
621 goto error;
622 }
623
624 new->fsuid = new->euid = kuid;
625
626 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
627 if (retval < 0)
628 goto error;
629
630 retval = set_cred_ucounts(new);
631 if (retval < 0)
632 goto error;
633
634 flag_nproc_exceeded(new);
635 return commit_creds(new);
636
637error:
638 abort_creds(new);
639 return retval;
640}
641
642SYSCALL_DEFINE1(setuid, uid_t, uid)
643{
644 return __sys_setuid(uid);
645}
646
647
648/*
649 * This function implements a generic ability to update ruid, euid,
650 * and suid. This allows you to implement the 4.4 compatible seteuid().
651 */
652long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
653{
654 struct user_namespace *ns = current_user_ns();
655 const struct cred *old;
656 struct cred *new;
657 int retval;
658 kuid_t kruid, keuid, ksuid;
659
660 kruid = make_kuid(ns, ruid);
661 keuid = make_kuid(ns, euid);
662 ksuid = make_kuid(ns, suid);
663
664 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
665 return -EINVAL;
666
667 if ((euid != (uid_t) -1) && !uid_valid(keuid))
668 return -EINVAL;
669
670 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
671 return -EINVAL;
672
673 new = prepare_creds();
674 if (!new)
675 return -ENOMEM;
676
677 old = current_cred();
678
679 retval = -EPERM;
680 if (!ns_capable_setid(old->user_ns, CAP_SETUID)) {
681 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
682 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
683 goto error;
684 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
685 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
686 goto error;
687 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
688 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
689 goto error;
690 }
691
692 if (ruid != (uid_t) -1) {
693 new->uid = kruid;
694 if (!uid_eq(kruid, old->uid)) {
695 retval = set_user(new);
696 if (retval < 0)
697 goto error;
698 }
699 }
700 if (euid != (uid_t) -1)
701 new->euid = keuid;
702 if (suid != (uid_t) -1)
703 new->suid = ksuid;
704 new->fsuid = new->euid;
705
706 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
707 if (retval < 0)
708 goto error;
709
710 retval = set_cred_ucounts(new);
711 if (retval < 0)
712 goto error;
713
714 flag_nproc_exceeded(new);
715 return commit_creds(new);
716
717error:
718 abort_creds(new);
719 return retval;
720}
721
722SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
723{
724 return __sys_setresuid(ruid, euid, suid);
725}
726
727SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
728{
729 const struct cred *cred = current_cred();
730 int retval;
731 uid_t ruid, euid, suid;
732
733 ruid = from_kuid_munged(cred->user_ns, cred->uid);
734 euid = from_kuid_munged(cred->user_ns, cred->euid);
735 suid = from_kuid_munged(cred->user_ns, cred->suid);
736
737 retval = put_user(ruid, ruidp);
738 if (!retval) {
739 retval = put_user(euid, euidp);
740 if (!retval)
741 return put_user(suid, suidp);
742 }
743 return retval;
744}
745
746/*
747 * Same as above, but for rgid, egid, sgid.
748 */
749long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
750{
751 struct user_namespace *ns = current_user_ns();
752 const struct cred *old;
753 struct cred *new;
754 int retval;
755 kgid_t krgid, kegid, ksgid;
756
757 krgid = make_kgid(ns, rgid);
758 kegid = make_kgid(ns, egid);
759 ksgid = make_kgid(ns, sgid);
760
761 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
762 return -EINVAL;
763 if ((egid != (gid_t) -1) && !gid_valid(kegid))
764 return -EINVAL;
765 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
766 return -EINVAL;
767
768 new = prepare_creds();
769 if (!new)
770 return -ENOMEM;
771 old = current_cred();
772
773 retval = -EPERM;
774 if (!ns_capable_setid(old->user_ns, CAP_SETGID)) {
775 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
776 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
777 goto error;
778 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
779 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
780 goto error;
781 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
782 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
783 goto error;
784 }
785
786 if (rgid != (gid_t) -1)
787 new->gid = krgid;
788 if (egid != (gid_t) -1)
789 new->egid = kegid;
790 if (sgid != (gid_t) -1)
791 new->sgid = ksgid;
792 new->fsgid = new->egid;
793
794 retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
795 if (retval < 0)
796 goto error;
797
798 return commit_creds(new);
799
800error:
801 abort_creds(new);
802 return retval;
803}
804
805SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
806{
807 return __sys_setresgid(rgid, egid, sgid);
808}
809
810SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
811{
812 const struct cred *cred = current_cred();
813 int retval;
814 gid_t rgid, egid, sgid;
815
816 rgid = from_kgid_munged(cred->user_ns, cred->gid);
817 egid = from_kgid_munged(cred->user_ns, cred->egid);
818 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
819
820 retval = put_user(rgid, rgidp);
821 if (!retval) {
822 retval = put_user(egid, egidp);
823 if (!retval)
824 retval = put_user(sgid, sgidp);
825 }
826
827 return retval;
828}
829
830
831/*
832 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
833 * is used for "access()" and for the NFS daemon (letting nfsd stay at
834 * whatever uid it wants to). It normally shadows "euid", except when
835 * explicitly set by setfsuid() or for access..
836 */
837long __sys_setfsuid(uid_t uid)
838{
839 const struct cred *old;
840 struct cred *new;
841 uid_t old_fsuid;
842 kuid_t kuid;
843
844 old = current_cred();
845 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
846
847 kuid = make_kuid(old->user_ns, uid);
848 if (!uid_valid(kuid))
849 return old_fsuid;
850
851 new = prepare_creds();
852 if (!new)
853 return old_fsuid;
854
855 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
856 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
857 ns_capable_setid(old->user_ns, CAP_SETUID)) {
858 if (!uid_eq(kuid, old->fsuid)) {
859 new->fsuid = kuid;
860 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
861 goto change_okay;
862 }
863 }
864
865 abort_creds(new);
866 return old_fsuid;
867
868change_okay:
869 commit_creds(new);
870 return old_fsuid;
871}
872
873SYSCALL_DEFINE1(setfsuid, uid_t, uid)
874{
875 return __sys_setfsuid(uid);
876}
877
878/*
879 * Samma på svenska..
880 */
881long __sys_setfsgid(gid_t gid)
882{
883 const struct cred *old;
884 struct cred *new;
885 gid_t old_fsgid;
886 kgid_t kgid;
887
888 old = current_cred();
889 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
890
891 kgid = make_kgid(old->user_ns, gid);
892 if (!gid_valid(kgid))
893 return old_fsgid;
894
895 new = prepare_creds();
896 if (!new)
897 return old_fsgid;
898
899 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
900 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
901 ns_capable_setid(old->user_ns, CAP_SETGID)) {
902 if (!gid_eq(kgid, old->fsgid)) {
903 new->fsgid = kgid;
904 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
905 goto change_okay;
906 }
907 }
908
909 abort_creds(new);
910 return old_fsgid;
911
912change_okay:
913 commit_creds(new);
914 return old_fsgid;
915}
916
917SYSCALL_DEFINE1(setfsgid, gid_t, gid)
918{
919 return __sys_setfsgid(gid);
920}
921#endif /* CONFIG_MULTIUSER */
922
923/**
924 * sys_getpid - return the thread group id of the current process
925 *
926 * Note, despite the name, this returns the tgid not the pid. The tgid and
927 * the pid are identical unless CLONE_THREAD was specified on clone() in
928 * which case the tgid is the same in all threads of the same group.
929 *
930 * This is SMP safe as current->tgid does not change.
931 */
932SYSCALL_DEFINE0(getpid)
933{
934 return task_tgid_vnr(current);
935}
936
937/* Thread ID - the internal kernel "pid" */
938SYSCALL_DEFINE0(gettid)
939{
940 return task_pid_vnr(current);
941}
942
943/*
944 * Accessing ->real_parent is not SMP-safe, it could
945 * change from under us. However, we can use a stale
946 * value of ->real_parent under rcu_read_lock(), see
947 * release_task()->call_rcu(delayed_put_task_struct).
948 */
949SYSCALL_DEFINE0(getppid)
950{
951 int pid;
952
953 rcu_read_lock();
954 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
955 rcu_read_unlock();
956
957 return pid;
958}
959
960SYSCALL_DEFINE0(getuid)
961{
962 /* Only we change this so SMP safe */
963 return from_kuid_munged(current_user_ns(), current_uid());
964}
965
966SYSCALL_DEFINE0(geteuid)
967{
968 /* Only we change this so SMP safe */
969 return from_kuid_munged(current_user_ns(), current_euid());
970}
971
972SYSCALL_DEFINE0(getgid)
973{
974 /* Only we change this so SMP safe */
975 return from_kgid_munged(current_user_ns(), current_gid());
976}
977
978SYSCALL_DEFINE0(getegid)
979{
980 /* Only we change this so SMP safe */
981 return from_kgid_munged(current_user_ns(), current_egid());
982}
983
984static void do_sys_times(struct tms *tms)
985{
986 u64 tgutime, tgstime, cutime, cstime;
987
988 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
989 cutime = current->signal->cutime;
990 cstime = current->signal->cstime;
991 tms->tms_utime = nsec_to_clock_t(tgutime);
992 tms->tms_stime = nsec_to_clock_t(tgstime);
993 tms->tms_cutime = nsec_to_clock_t(cutime);
994 tms->tms_cstime = nsec_to_clock_t(cstime);
995}
996
997SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
998{
999 if (tbuf) {
1000 struct tms tmp;
1001
1002 do_sys_times(&tmp);
1003 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1004 return -EFAULT;
1005 }
1006 force_successful_syscall_return();
1007 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1008}
1009
1010#ifdef CONFIG_COMPAT
1011static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
1012{
1013 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
1014}
1015
1016COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
1017{
1018 if (tbuf) {
1019 struct tms tms;
1020 struct compat_tms tmp;
1021
1022 do_sys_times(&tms);
1023 /* Convert our struct tms to the compat version. */
1024 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
1025 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
1026 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
1027 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
1028 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
1029 return -EFAULT;
1030 }
1031 force_successful_syscall_return();
1032 return compat_jiffies_to_clock_t(jiffies);
1033}
1034#endif
1035
1036/*
1037 * This needs some heavy checking ...
1038 * I just haven't the stomach for it. I also don't fully
1039 * understand sessions/pgrp etc. Let somebody who does explain it.
1040 *
1041 * OK, I think I have the protection semantics right.... this is really
1042 * only important on a multi-user system anyway, to make sure one user
1043 * can't send a signal to a process owned by another. -TYT, 12/12/91
1044 *
1045 * !PF_FORKNOEXEC check to conform completely to POSIX.
1046 */
1047SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1048{
1049 struct task_struct *p;
1050 struct task_struct *group_leader = current->group_leader;
1051 struct pid *pgrp;
1052 int err;
1053
1054 if (!pid)
1055 pid = task_pid_vnr(group_leader);
1056 if (!pgid)
1057 pgid = pid;
1058 if (pgid < 0)
1059 return -EINVAL;
1060 rcu_read_lock();
1061
1062 /* From this point forward we keep holding onto the tasklist lock
1063 * so that our parent does not change from under us. -DaveM
1064 */
1065 write_lock_irq(&tasklist_lock);
1066
1067 err = -ESRCH;
1068 p = find_task_by_vpid(pid);
1069 if (!p)
1070 goto out;
1071
1072 err = -EINVAL;
1073 if (!thread_group_leader(p))
1074 goto out;
1075
1076 if (same_thread_group(p->real_parent, group_leader)) {
1077 err = -EPERM;
1078 if (task_session(p) != task_session(group_leader))
1079 goto out;
1080 err = -EACCES;
1081 if (!(p->flags & PF_FORKNOEXEC))
1082 goto out;
1083 } else {
1084 err = -ESRCH;
1085 if (p != group_leader)
1086 goto out;
1087 }
1088
1089 err = -EPERM;
1090 if (p->signal->leader)
1091 goto out;
1092
1093 pgrp = task_pid(p);
1094 if (pgid != pid) {
1095 struct task_struct *g;
1096
1097 pgrp = find_vpid(pgid);
1098 g = pid_task(pgrp, PIDTYPE_PGID);
1099 if (!g || task_session(g) != task_session(group_leader))
1100 goto out;
1101 }
1102
1103 err = security_task_setpgid(p, pgid);
1104 if (err)
1105 goto out;
1106
1107 if (task_pgrp(p) != pgrp)
1108 change_pid(p, PIDTYPE_PGID, pgrp);
1109
1110 err = 0;
1111out:
1112 /* All paths lead to here, thus we are safe. -DaveM */
1113 write_unlock_irq(&tasklist_lock);
1114 rcu_read_unlock();
1115 return err;
1116}
1117
1118static int do_getpgid(pid_t pid)
1119{
1120 struct task_struct *p;
1121 struct pid *grp;
1122 int retval;
1123
1124 rcu_read_lock();
1125 if (!pid)
1126 grp = task_pgrp(current);
1127 else {
1128 retval = -ESRCH;
1129 p = find_task_by_vpid(pid);
1130 if (!p)
1131 goto out;
1132 grp = task_pgrp(p);
1133 if (!grp)
1134 goto out;
1135
1136 retval = security_task_getpgid(p);
1137 if (retval)
1138 goto out;
1139 }
1140 retval = pid_vnr(grp);
1141out:
1142 rcu_read_unlock();
1143 return retval;
1144}
1145
1146SYSCALL_DEFINE1(getpgid, pid_t, pid)
1147{
1148 return do_getpgid(pid);
1149}
1150
1151#ifdef __ARCH_WANT_SYS_GETPGRP
1152
1153SYSCALL_DEFINE0(getpgrp)
1154{
1155 return do_getpgid(0);
1156}
1157
1158#endif
1159
1160SYSCALL_DEFINE1(getsid, pid_t, pid)
1161{
1162 struct task_struct *p;
1163 struct pid *sid;
1164 int retval;
1165
1166 rcu_read_lock();
1167 if (!pid)
1168 sid = task_session(current);
1169 else {
1170 retval = -ESRCH;
1171 p = find_task_by_vpid(pid);
1172 if (!p)
1173 goto out;
1174 sid = task_session(p);
1175 if (!sid)
1176 goto out;
1177
1178 retval = security_task_getsid(p);
1179 if (retval)
1180 goto out;
1181 }
1182 retval = pid_vnr(sid);
1183out:
1184 rcu_read_unlock();
1185 return retval;
1186}
1187
1188static void set_special_pids(struct pid *pid)
1189{
1190 struct task_struct *curr = current->group_leader;
1191
1192 if (task_session(curr) != pid)
1193 change_pid(curr, PIDTYPE_SID, pid);
1194
1195 if (task_pgrp(curr) != pid)
1196 change_pid(curr, PIDTYPE_PGID, pid);
1197}
1198
1199int ksys_setsid(void)
1200{
1201 struct task_struct *group_leader = current->group_leader;
1202 struct pid *sid = task_pid(group_leader);
1203 pid_t session = pid_vnr(sid);
1204 int err = -EPERM;
1205
1206 write_lock_irq(&tasklist_lock);
1207 /* Fail if I am already a session leader */
1208 if (group_leader->signal->leader)
1209 goto out;
1210
1211 /* Fail if a process group id already exists that equals the
1212 * proposed session id.
1213 */
1214 if (pid_task(sid, PIDTYPE_PGID))
1215 goto out;
1216
1217 group_leader->signal->leader = 1;
1218 set_special_pids(sid);
1219
1220 proc_clear_tty(group_leader);
1221
1222 err = session;
1223out:
1224 write_unlock_irq(&tasklist_lock);
1225 if (err > 0) {
1226 proc_sid_connector(group_leader);
1227 sched_autogroup_create_attach(group_leader);
1228 }
1229 return err;
1230}
1231
1232SYSCALL_DEFINE0(setsid)
1233{
1234 return ksys_setsid();
1235}
1236
1237DECLARE_RWSEM(uts_sem);
1238
1239#ifdef COMPAT_UTS_MACHINE
1240#define override_architecture(name) \
1241 (personality(current->personality) == PER_LINUX32 && \
1242 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1243 sizeof(COMPAT_UTS_MACHINE)))
1244#else
1245#define override_architecture(name) 0
1246#endif
1247
1248/*
1249 * Work around broken programs that cannot handle "Linux 3.0".
1250 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1251 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be
1252 * 2.6.60.
1253 */
1254static int override_release(char __user *release, size_t len)
1255{
1256 int ret = 0;
1257
1258 if (current->personality & UNAME26) {
1259 const char *rest = UTS_RELEASE;
1260 char buf[65] = { 0 };
1261 int ndots = 0;
1262 unsigned v;
1263 size_t copy;
1264
1265 while (*rest) {
1266 if (*rest == '.' && ++ndots >= 3)
1267 break;
1268 if (!isdigit(*rest) && *rest != '.')
1269 break;
1270 rest++;
1271 }
1272 v = LINUX_VERSION_PATCHLEVEL + 60;
1273 copy = clamp_t(size_t, len, 1, sizeof(buf));
1274 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1275 ret = copy_to_user(release, buf, copy + 1);
1276 }
1277 return ret;
1278}
1279
1280SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1281{
1282 struct new_utsname tmp;
1283
1284 down_read(&uts_sem);
1285 memcpy(&tmp, utsname(), sizeof(tmp));
1286 up_read(&uts_sem);
1287 if (copy_to_user(name, &tmp, sizeof(tmp)))
1288 return -EFAULT;
1289
1290 if (override_release(name->release, sizeof(name->release)))
1291 return -EFAULT;
1292 if (override_architecture(name))
1293 return -EFAULT;
1294 return 0;
1295}
1296
1297#ifdef __ARCH_WANT_SYS_OLD_UNAME
1298/*
1299 * Old cruft
1300 */
1301SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1302{
1303 struct old_utsname tmp;
1304
1305 if (!name)
1306 return -EFAULT;
1307
1308 down_read(&uts_sem);
1309 memcpy(&tmp, utsname(), sizeof(tmp));
1310 up_read(&uts_sem);
1311 if (copy_to_user(name, &tmp, sizeof(tmp)))
1312 return -EFAULT;
1313
1314 if (override_release(name->release, sizeof(name->release)))
1315 return -EFAULT;
1316 if (override_architecture(name))
1317 return -EFAULT;
1318 return 0;
1319}
1320
1321SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1322{
1323 struct oldold_utsname tmp;
1324
1325 if (!name)
1326 return -EFAULT;
1327
1328 memset(&tmp, 0, sizeof(tmp));
1329
1330 down_read(&uts_sem);
1331 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1332 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1333 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1334 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1335 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
1336 up_read(&uts_sem);
1337 if (copy_to_user(name, &tmp, sizeof(tmp)))
1338 return -EFAULT;
1339
1340 if (override_architecture(name))
1341 return -EFAULT;
1342 if (override_release(name->release, sizeof(name->release)))
1343 return -EFAULT;
1344 return 0;
1345}
1346#endif
1347
1348SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1349{
1350 int errno;
1351 char tmp[__NEW_UTS_LEN];
1352
1353 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1354 return -EPERM;
1355
1356 if (len < 0 || len > __NEW_UTS_LEN)
1357 return -EINVAL;
1358 errno = -EFAULT;
1359 if (!copy_from_user(tmp, name, len)) {
1360 struct new_utsname *u;
1361
1362 down_write(&uts_sem);
1363 u = utsname();
1364 memcpy(u->nodename, tmp, len);
1365 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1366 errno = 0;
1367 uts_proc_notify(UTS_PROC_HOSTNAME);
1368 up_write(&uts_sem);
1369 }
1370 return errno;
1371}
1372
1373#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1374
1375SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1376{
1377 int i;
1378 struct new_utsname *u;
1379 char tmp[__NEW_UTS_LEN + 1];
1380
1381 if (len < 0)
1382 return -EINVAL;
1383 down_read(&uts_sem);
1384 u = utsname();
1385 i = 1 + strlen(u->nodename);
1386 if (i > len)
1387 i = len;
1388 memcpy(tmp, u->nodename, i);
1389 up_read(&uts_sem);
1390 if (copy_to_user(name, tmp, i))
1391 return -EFAULT;
1392 return 0;
1393}
1394
1395#endif
1396
1397/*
1398 * Only setdomainname; getdomainname can be implemented by calling
1399 * uname()
1400 */
1401SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1402{
1403 int errno;
1404 char tmp[__NEW_UTS_LEN];
1405
1406 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1407 return -EPERM;
1408 if (len < 0 || len > __NEW_UTS_LEN)
1409 return -EINVAL;
1410
1411 errno = -EFAULT;
1412 if (!copy_from_user(tmp, name, len)) {
1413 struct new_utsname *u;
1414
1415 down_write(&uts_sem);
1416 u = utsname();
1417 memcpy(u->domainname, tmp, len);
1418 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1419 errno = 0;
1420 uts_proc_notify(UTS_PROC_DOMAINNAME);
1421 up_write(&uts_sem);
1422 }
1423 return errno;
1424}
1425
1426SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1427{
1428 struct rlimit value;
1429 int ret;
1430
1431 ret = do_prlimit(current, resource, NULL, &value);
1432 if (!ret)
1433 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1434
1435 return ret;
1436}
1437
1438#ifdef CONFIG_COMPAT
1439
1440COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1441 struct compat_rlimit __user *, rlim)
1442{
1443 struct rlimit r;
1444 struct compat_rlimit r32;
1445
1446 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1447 return -EFAULT;
1448
1449 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1450 r.rlim_cur = RLIM_INFINITY;
1451 else
1452 r.rlim_cur = r32.rlim_cur;
1453 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1454 r.rlim_max = RLIM_INFINITY;
1455 else
1456 r.rlim_max = r32.rlim_max;
1457 return do_prlimit(current, resource, &r, NULL);
1458}
1459
1460COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1461 struct compat_rlimit __user *, rlim)
1462{
1463 struct rlimit r;
1464 int ret;
1465
1466 ret = do_prlimit(current, resource, NULL, &r);
1467 if (!ret) {
1468 struct compat_rlimit r32;
1469 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1470 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1471 else
1472 r32.rlim_cur = r.rlim_cur;
1473 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1474 r32.rlim_max = COMPAT_RLIM_INFINITY;
1475 else
1476 r32.rlim_max = r.rlim_max;
1477
1478 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1479 return -EFAULT;
1480 }
1481 return ret;
1482}
1483
1484#endif
1485
1486#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1487
1488/*
1489 * Back compatibility for getrlimit. Needed for some apps.
1490 */
1491SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1492 struct rlimit __user *, rlim)
1493{
1494 struct rlimit x;
1495 if (resource >= RLIM_NLIMITS)
1496 return -EINVAL;
1497
1498 resource = array_index_nospec(resource, RLIM_NLIMITS);
1499 task_lock(current->group_leader);
1500 x = current->signal->rlim[resource];
1501 task_unlock(current->group_leader);
1502 if (x.rlim_cur > 0x7FFFFFFF)
1503 x.rlim_cur = 0x7FFFFFFF;
1504 if (x.rlim_max > 0x7FFFFFFF)
1505 x.rlim_max = 0x7FFFFFFF;
1506 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1507}
1508
1509#ifdef CONFIG_COMPAT
1510COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1511 struct compat_rlimit __user *, rlim)
1512{
1513 struct rlimit r;
1514
1515 if (resource >= RLIM_NLIMITS)
1516 return -EINVAL;
1517
1518 resource = array_index_nospec(resource, RLIM_NLIMITS);
1519 task_lock(current->group_leader);
1520 r = current->signal->rlim[resource];
1521 task_unlock(current->group_leader);
1522 if (r.rlim_cur > 0x7FFFFFFF)
1523 r.rlim_cur = 0x7FFFFFFF;
1524 if (r.rlim_max > 0x7FFFFFFF)
1525 r.rlim_max = 0x7FFFFFFF;
1526
1527 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1528 put_user(r.rlim_max, &rlim->rlim_max))
1529 return -EFAULT;
1530 return 0;
1531}
1532#endif
1533
1534#endif
1535
1536static inline bool rlim64_is_infinity(__u64 rlim64)
1537{
1538#if BITS_PER_LONG < 64
1539 return rlim64 >= ULONG_MAX;
1540#else
1541 return rlim64 == RLIM64_INFINITY;
1542#endif
1543}
1544
1545static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1546{
1547 if (rlim->rlim_cur == RLIM_INFINITY)
1548 rlim64->rlim_cur = RLIM64_INFINITY;
1549 else
1550 rlim64->rlim_cur = rlim->rlim_cur;
1551 if (rlim->rlim_max == RLIM_INFINITY)
1552 rlim64->rlim_max = RLIM64_INFINITY;
1553 else
1554 rlim64->rlim_max = rlim->rlim_max;
1555}
1556
1557static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1558{
1559 if (rlim64_is_infinity(rlim64->rlim_cur))
1560 rlim->rlim_cur = RLIM_INFINITY;
1561 else
1562 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1563 if (rlim64_is_infinity(rlim64->rlim_max))
1564 rlim->rlim_max = RLIM_INFINITY;
1565 else
1566 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1567}
1568
1569/* make sure you are allowed to change @tsk limits before calling this */
1570int do_prlimit(struct task_struct *tsk, unsigned int resource,
1571 struct rlimit *new_rlim, struct rlimit *old_rlim)
1572{
1573 struct rlimit *rlim;
1574 int retval = 0;
1575
1576 if (resource >= RLIM_NLIMITS)
1577 return -EINVAL;
1578 if (new_rlim) {
1579 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1580 return -EINVAL;
1581 if (resource == RLIMIT_NOFILE &&
1582 new_rlim->rlim_max > sysctl_nr_open)
1583 return -EPERM;
1584 }
1585
1586 /* protect tsk->signal and tsk->sighand from disappearing */
1587 read_lock(&tasklist_lock);
1588 if (!tsk->sighand) {
1589 retval = -ESRCH;
1590 goto out;
1591 }
1592
1593 rlim = tsk->signal->rlim + resource;
1594 task_lock(tsk->group_leader);
1595 if (new_rlim) {
1596 /* Keep the capable check against init_user_ns until
1597 cgroups can contain all limits */
1598 if (new_rlim->rlim_max > rlim->rlim_max &&
1599 !capable(CAP_SYS_RESOURCE))
1600 retval = -EPERM;
1601 if (!retval)
1602 retval = security_task_setrlimit(tsk, resource, new_rlim);
1603 }
1604 if (!retval) {
1605 if (old_rlim)
1606 *old_rlim = *rlim;
1607 if (new_rlim)
1608 *rlim = *new_rlim;
1609 }
1610 task_unlock(tsk->group_leader);
1611
1612 /*
1613 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
1614 * infinite. In case of RLIM_INFINITY the posix CPU timer code
1615 * ignores the rlimit.
1616 */
1617 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1618 new_rlim->rlim_cur != RLIM_INFINITY &&
1619 IS_ENABLED(CONFIG_POSIX_TIMERS))
1620 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1621out:
1622 read_unlock(&tasklist_lock);
1623 return retval;
1624}
1625
1626/* rcu lock must be held */
1627static int check_prlimit_permission(struct task_struct *task,
1628 unsigned int flags)
1629{
1630 const struct cred *cred = current_cred(), *tcred;
1631 bool id_match;
1632
1633 if (current == task)
1634 return 0;
1635
1636 tcred = __task_cred(task);
1637 id_match = (uid_eq(cred->uid, tcred->euid) &&
1638 uid_eq(cred->uid, tcred->suid) &&
1639 uid_eq(cred->uid, tcred->uid) &&
1640 gid_eq(cred->gid, tcred->egid) &&
1641 gid_eq(cred->gid, tcred->sgid) &&
1642 gid_eq(cred->gid, tcred->gid));
1643 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1644 return -EPERM;
1645
1646 return security_task_prlimit(cred, tcred, flags);
1647}
1648
1649SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1650 const struct rlimit64 __user *, new_rlim,
1651 struct rlimit64 __user *, old_rlim)
1652{
1653 struct rlimit64 old64, new64;
1654 struct rlimit old, new;
1655 struct task_struct *tsk;
1656 unsigned int checkflags = 0;
1657 int ret;
1658
1659 if (old_rlim)
1660 checkflags |= LSM_PRLIMIT_READ;
1661
1662 if (new_rlim) {
1663 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1664 return -EFAULT;
1665 rlim64_to_rlim(&new64, &new);
1666 checkflags |= LSM_PRLIMIT_WRITE;
1667 }
1668
1669 rcu_read_lock();
1670 tsk = pid ? find_task_by_vpid(pid) : current;
1671 if (!tsk) {
1672 rcu_read_unlock();
1673 return -ESRCH;
1674 }
1675 ret = check_prlimit_permission(tsk, checkflags);
1676 if (ret) {
1677 rcu_read_unlock();
1678 return ret;
1679 }
1680 get_task_struct(tsk);
1681 rcu_read_unlock();
1682
1683 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1684 old_rlim ? &old : NULL);
1685
1686 if (!ret && old_rlim) {
1687 rlim_to_rlim64(&old, &old64);
1688 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1689 ret = -EFAULT;
1690 }
1691
1692 put_task_struct(tsk);
1693 return ret;
1694}
1695
1696SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1697{
1698 struct rlimit new_rlim;
1699
1700 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1701 return -EFAULT;
1702 return do_prlimit(current, resource, &new_rlim, NULL);
1703}
1704
1705/*
1706 * It would make sense to put struct rusage in the task_struct,
1707 * except that would make the task_struct be *really big*. After
1708 * task_struct gets moved into malloc'ed memory, it would
1709 * make sense to do this. It will make moving the rest of the information
1710 * a lot simpler! (Which we're not doing right now because we're not
1711 * measuring them yet).
1712 *
1713 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1714 * races with threads incrementing their own counters. But since word
1715 * reads are atomic, we either get new values or old values and we don't
1716 * care which for the sums. We always take the siglock to protect reading
1717 * the c* fields from p->signal from races with exit.c updating those
1718 * fields when reaping, so a sample either gets all the additions of a
1719 * given child after it's reaped, or none so this sample is before reaping.
1720 *
1721 * Locking:
1722 * We need to take the siglock for CHILDEREN, SELF and BOTH
1723 * for the cases current multithreaded, non-current single threaded
1724 * non-current multithreaded. Thread traversal is now safe with
1725 * the siglock held.
1726 * Strictly speaking, we donot need to take the siglock if we are current and
1727 * single threaded, as no one else can take our signal_struct away, no one
1728 * else can reap the children to update signal->c* counters, and no one else
1729 * can race with the signal-> fields. If we do not take any lock, the
1730 * signal-> fields could be read out of order while another thread was just
1731 * exiting. So we should place a read memory barrier when we avoid the lock.
1732 * On the writer side, write memory barrier is implied in __exit_signal
1733 * as __exit_signal releases the siglock spinlock after updating the signal->
1734 * fields. But we don't do this yet to keep things simple.
1735 *
1736 */
1737
1738static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1739{
1740 r->ru_nvcsw += t->nvcsw;
1741 r->ru_nivcsw += t->nivcsw;
1742 r->ru_minflt += t->min_flt;
1743 r->ru_majflt += t->maj_flt;
1744 r->ru_inblock += task_io_get_inblock(t);
1745 r->ru_oublock += task_io_get_oublock(t);
1746}
1747
1748void getrusage(struct task_struct *p, int who, struct rusage *r)
1749{
1750 struct task_struct *t;
1751 unsigned long flags;
1752 u64 tgutime, tgstime, utime, stime;
1753 unsigned long maxrss = 0;
1754
1755 memset((char *)r, 0, sizeof (*r));
1756 utime = stime = 0;
1757
1758 if (who == RUSAGE_THREAD) {
1759 task_cputime_adjusted(current, &utime, &stime);
1760 accumulate_thread_rusage(p, r);
1761 maxrss = p->signal->maxrss;
1762 goto out;
1763 }
1764
1765 if (!lock_task_sighand(p, &flags))
1766 return;
1767
1768 switch (who) {
1769 case RUSAGE_BOTH:
1770 case RUSAGE_CHILDREN:
1771 utime = p->signal->cutime;
1772 stime = p->signal->cstime;
1773 r->ru_nvcsw = p->signal->cnvcsw;
1774 r->ru_nivcsw = p->signal->cnivcsw;
1775 r->ru_minflt = p->signal->cmin_flt;
1776 r->ru_majflt = p->signal->cmaj_flt;
1777 r->ru_inblock = p->signal->cinblock;
1778 r->ru_oublock = p->signal->coublock;
1779 maxrss = p->signal->cmaxrss;
1780
1781 if (who == RUSAGE_CHILDREN)
1782 break;
1783 fallthrough;
1784
1785 case RUSAGE_SELF:
1786 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1787 utime += tgutime;
1788 stime += tgstime;
1789 r->ru_nvcsw += p->signal->nvcsw;
1790 r->ru_nivcsw += p->signal->nivcsw;
1791 r->ru_minflt += p->signal->min_flt;
1792 r->ru_majflt += p->signal->maj_flt;
1793 r->ru_inblock += p->signal->inblock;
1794 r->ru_oublock += p->signal->oublock;
1795 if (maxrss < p->signal->maxrss)
1796 maxrss = p->signal->maxrss;
1797 t = p;
1798 do {
1799 accumulate_thread_rusage(t, r);
1800 } while_each_thread(p, t);
1801 break;
1802
1803 default:
1804 BUG();
1805 }
1806 unlock_task_sighand(p, &flags);
1807
1808out:
1809 r->ru_utime = ns_to_kernel_old_timeval(utime);
1810 r->ru_stime = ns_to_kernel_old_timeval(stime);
1811
1812 if (who != RUSAGE_CHILDREN) {
1813 struct mm_struct *mm = get_task_mm(p);
1814
1815 if (mm) {
1816 setmax_mm_hiwater_rss(&maxrss, mm);
1817 mmput(mm);
1818 }
1819 }
1820 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1821}
1822
1823SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1824{
1825 struct rusage r;
1826
1827 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1828 who != RUSAGE_THREAD)
1829 return -EINVAL;
1830
1831 getrusage(current, who, &r);
1832 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1833}
1834
1835#ifdef CONFIG_COMPAT
1836COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1837{
1838 struct rusage r;
1839
1840 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1841 who != RUSAGE_THREAD)
1842 return -EINVAL;
1843
1844 getrusage(current, who, &r);
1845 return put_compat_rusage(&r, ru);
1846}
1847#endif
1848
1849SYSCALL_DEFINE1(umask, int, mask)
1850{
1851 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1852 return mask;
1853}
1854
1855static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1856{
1857 struct fd exe;
1858 struct inode *inode;
1859 int err;
1860
1861 exe = fdget(fd);
1862 if (!exe.file)
1863 return -EBADF;
1864
1865 inode = file_inode(exe.file);
1866
1867 /*
1868 * Because the original mm->exe_file points to executable file, make
1869 * sure that this one is executable as well, to avoid breaking an
1870 * overall picture.
1871 */
1872 err = -EACCES;
1873 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
1874 goto exit;
1875
1876 err = file_permission(exe.file, MAY_EXEC);
1877 if (err)
1878 goto exit;
1879
1880 err = replace_mm_exe_file(mm, exe.file);
1881exit:
1882 fdput(exe);
1883 return err;
1884}
1885
1886/*
1887 * Check arithmetic relations of passed addresses.
1888 *
1889 * WARNING: we don't require any capability here so be very careful
1890 * in what is allowed for modification from userspace.
1891 */
1892static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
1893{
1894 unsigned long mmap_max_addr = TASK_SIZE;
1895 int error = -EINVAL, i;
1896
1897 static const unsigned char offsets[] = {
1898 offsetof(struct prctl_mm_map, start_code),
1899 offsetof(struct prctl_mm_map, end_code),
1900 offsetof(struct prctl_mm_map, start_data),
1901 offsetof(struct prctl_mm_map, end_data),
1902 offsetof(struct prctl_mm_map, start_brk),
1903 offsetof(struct prctl_mm_map, brk),
1904 offsetof(struct prctl_mm_map, start_stack),
1905 offsetof(struct prctl_mm_map, arg_start),
1906 offsetof(struct prctl_mm_map, arg_end),
1907 offsetof(struct prctl_mm_map, env_start),
1908 offsetof(struct prctl_mm_map, env_end),
1909 };
1910
1911 /*
1912 * Make sure the members are not somewhere outside
1913 * of allowed address space.
1914 */
1915 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1916 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1917
1918 if ((unsigned long)val >= mmap_max_addr ||
1919 (unsigned long)val < mmap_min_addr)
1920 goto out;
1921 }
1922
1923 /*
1924 * Make sure the pairs are ordered.
1925 */
1926#define __prctl_check_order(__m1, __op, __m2) \
1927 ((unsigned long)prctl_map->__m1 __op \
1928 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1929 error = __prctl_check_order(start_code, <, end_code);
1930 error |= __prctl_check_order(start_data,<=, end_data);
1931 error |= __prctl_check_order(start_brk, <=, brk);
1932 error |= __prctl_check_order(arg_start, <=, arg_end);
1933 error |= __prctl_check_order(env_start, <=, env_end);
1934 if (error)
1935 goto out;
1936#undef __prctl_check_order
1937
1938 error = -EINVAL;
1939
1940 /*
1941 * Neither we should allow to override limits if they set.
1942 */
1943 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1944 prctl_map->start_brk, prctl_map->end_data,
1945 prctl_map->start_data))
1946 goto out;
1947
1948 error = 0;
1949out:
1950 return error;
1951}
1952
1953#ifdef CONFIG_CHECKPOINT_RESTORE
1954static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1955{
1956 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1957 unsigned long user_auxv[AT_VECTOR_SIZE];
1958 struct mm_struct *mm = current->mm;
1959 int error;
1960
1961 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1962 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1963
1964 if (opt == PR_SET_MM_MAP_SIZE)
1965 return put_user((unsigned int)sizeof(prctl_map),
1966 (unsigned int __user *)addr);
1967
1968 if (data_size != sizeof(prctl_map))
1969 return -EINVAL;
1970
1971 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1972 return -EFAULT;
1973
1974 error = validate_prctl_map_addr(&prctl_map);
1975 if (error)
1976 return error;
1977
1978 if (prctl_map.auxv_size) {
1979 /*
1980 * Someone is trying to cheat the auxv vector.
1981 */
1982 if (!prctl_map.auxv ||
1983 prctl_map.auxv_size > sizeof(mm->saved_auxv))
1984 return -EINVAL;
1985
1986 memset(user_auxv, 0, sizeof(user_auxv));
1987 if (copy_from_user(user_auxv,
1988 (const void __user *)prctl_map.auxv,
1989 prctl_map.auxv_size))
1990 return -EFAULT;
1991
1992 /* Last entry must be AT_NULL as specification requires */
1993 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
1994 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
1995 }
1996
1997 if (prctl_map.exe_fd != (u32)-1) {
1998 /*
1999 * Check if the current user is checkpoint/restore capable.
2000 * At the time of this writing, it checks for CAP_SYS_ADMIN
2001 * or CAP_CHECKPOINT_RESTORE.
2002 * Note that a user with access to ptrace can masquerade an
2003 * arbitrary program as any executable, even setuid ones.
2004 * This may have implications in the tomoyo subsystem.
2005 */
2006 if (!checkpoint_restore_ns_capable(current_user_ns()))
2007 return -EPERM;
2008
2009 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
2010 if (error)
2011 return error;
2012 }
2013
2014 /*
2015 * arg_lock protects concurrent updates but we still need mmap_lock for
2016 * read to exclude races with sys_brk.
2017 */
2018 mmap_read_lock(mm);
2019
2020 /*
2021 * We don't validate if these members are pointing to
2022 * real present VMAs because application may have correspond
2023 * VMAs already unmapped and kernel uses these members for statistics
2024 * output in procfs mostly, except
2025 *
2026 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups
2027 * for VMAs when updating these members so anything wrong written
2028 * here cause kernel to swear at userspace program but won't lead
2029 * to any problem in kernel itself
2030 */
2031
2032 spin_lock(&mm->arg_lock);
2033 mm->start_code = prctl_map.start_code;
2034 mm->end_code = prctl_map.end_code;
2035 mm->start_data = prctl_map.start_data;
2036 mm->end_data = prctl_map.end_data;
2037 mm->start_brk = prctl_map.start_brk;
2038 mm->brk = prctl_map.brk;
2039 mm->start_stack = prctl_map.start_stack;
2040 mm->arg_start = prctl_map.arg_start;
2041 mm->arg_end = prctl_map.arg_end;
2042 mm->env_start = prctl_map.env_start;
2043 mm->env_end = prctl_map.env_end;
2044 spin_unlock(&mm->arg_lock);
2045
2046 /*
2047 * Note this update of @saved_auxv is lockless thus
2048 * if someone reads this member in procfs while we're
2049 * updating -- it may get partly updated results. It's
2050 * known and acceptable trade off: we leave it as is to
2051 * not introduce additional locks here making the kernel
2052 * more complex.
2053 */
2054 if (prctl_map.auxv_size)
2055 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2056
2057 mmap_read_unlock(mm);
2058 return 0;
2059}
2060#endif /* CONFIG_CHECKPOINT_RESTORE */
2061
2062static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2063 unsigned long len)
2064{
2065 /*
2066 * This doesn't move the auxiliary vector itself since it's pinned to
2067 * mm_struct, but it permits filling the vector with new values. It's
2068 * up to the caller to provide sane values here, otherwise userspace
2069 * tools which use this vector might be unhappy.
2070 */
2071 unsigned long user_auxv[AT_VECTOR_SIZE] = {};
2072
2073 if (len > sizeof(user_auxv))
2074 return -EINVAL;
2075
2076 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2077 return -EFAULT;
2078
2079 /* Make sure the last entry is always AT_NULL */
2080 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2081 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2082
2083 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2084
2085 task_lock(current);
2086 memcpy(mm->saved_auxv, user_auxv, len);
2087 task_unlock(current);
2088
2089 return 0;
2090}
2091
2092static int prctl_set_mm(int opt, unsigned long addr,
2093 unsigned long arg4, unsigned long arg5)
2094{
2095 struct mm_struct *mm = current->mm;
2096 struct prctl_mm_map prctl_map = {
2097 .auxv = NULL,
2098 .auxv_size = 0,
2099 .exe_fd = -1,
2100 };
2101 struct vm_area_struct *vma;
2102 int error;
2103
2104 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2105 opt != PR_SET_MM_MAP &&
2106 opt != PR_SET_MM_MAP_SIZE)))
2107 return -EINVAL;
2108
2109#ifdef CONFIG_CHECKPOINT_RESTORE
2110 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2111 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2112#endif
2113
2114 if (!capable(CAP_SYS_RESOURCE))
2115 return -EPERM;
2116
2117 if (opt == PR_SET_MM_EXE_FILE)
2118 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
2119
2120 if (opt == PR_SET_MM_AUXV)
2121 return prctl_set_auxv(mm, addr, arg4);
2122
2123 if (addr >= TASK_SIZE || addr < mmap_min_addr)
2124 return -EINVAL;
2125
2126 error = -EINVAL;
2127
2128 /*
2129 * arg_lock protects concurrent updates of arg boundaries, we need
2130 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
2131 * validation.
2132 */
2133 mmap_read_lock(mm);
2134 vma = find_vma(mm, addr);
2135
2136 spin_lock(&mm->arg_lock);
2137 prctl_map.start_code = mm->start_code;
2138 prctl_map.end_code = mm->end_code;
2139 prctl_map.start_data = mm->start_data;
2140 prctl_map.end_data = mm->end_data;
2141 prctl_map.start_brk = mm->start_brk;
2142 prctl_map.brk = mm->brk;
2143 prctl_map.start_stack = mm->start_stack;
2144 prctl_map.arg_start = mm->arg_start;
2145 prctl_map.arg_end = mm->arg_end;
2146 prctl_map.env_start = mm->env_start;
2147 prctl_map.env_end = mm->env_end;
2148
2149 switch (opt) {
2150 case PR_SET_MM_START_CODE:
2151 prctl_map.start_code = addr;
2152 break;
2153 case PR_SET_MM_END_CODE:
2154 prctl_map.end_code = addr;
2155 break;
2156 case PR_SET_MM_START_DATA:
2157 prctl_map.start_data = addr;
2158 break;
2159 case PR_SET_MM_END_DATA:
2160 prctl_map.end_data = addr;
2161 break;
2162 case PR_SET_MM_START_STACK:
2163 prctl_map.start_stack = addr;
2164 break;
2165 case PR_SET_MM_START_BRK:
2166 prctl_map.start_brk = addr;
2167 break;
2168 case PR_SET_MM_BRK:
2169 prctl_map.brk = addr;
2170 break;
2171 case PR_SET_MM_ARG_START:
2172 prctl_map.arg_start = addr;
2173 break;
2174 case PR_SET_MM_ARG_END:
2175 prctl_map.arg_end = addr;
2176 break;
2177 case PR_SET_MM_ENV_START:
2178 prctl_map.env_start = addr;
2179 break;
2180 case PR_SET_MM_ENV_END:
2181 prctl_map.env_end = addr;
2182 break;
2183 default:
2184 goto out;
2185 }
2186
2187 error = validate_prctl_map_addr(&prctl_map);
2188 if (error)
2189 goto out;
2190
2191 switch (opt) {
2192 /*
2193 * If command line arguments and environment
2194 * are placed somewhere else on stack, we can
2195 * set them up here, ARG_START/END to setup
2196 * command line arguments and ENV_START/END
2197 * for environment.
2198 */
2199 case PR_SET_MM_START_STACK:
2200 case PR_SET_MM_ARG_START:
2201 case PR_SET_MM_ARG_END:
2202 case PR_SET_MM_ENV_START:
2203 case PR_SET_MM_ENV_END:
2204 if (!vma) {
2205 error = -EFAULT;
2206 goto out;
2207 }
2208 }
2209
2210 mm->start_code = prctl_map.start_code;
2211 mm->end_code = prctl_map.end_code;
2212 mm->start_data = prctl_map.start_data;
2213 mm->end_data = prctl_map.end_data;
2214 mm->start_brk = prctl_map.start_brk;
2215 mm->brk = prctl_map.brk;
2216 mm->start_stack = prctl_map.start_stack;
2217 mm->arg_start = prctl_map.arg_start;
2218 mm->arg_end = prctl_map.arg_end;
2219 mm->env_start = prctl_map.env_start;
2220 mm->env_end = prctl_map.env_end;
2221
2222 error = 0;
2223out:
2224 spin_unlock(&mm->arg_lock);
2225 mmap_read_unlock(mm);
2226 return error;
2227}
2228
2229#ifdef CONFIG_CHECKPOINT_RESTORE
2230static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2231{
2232 return put_user(me->clear_child_tid, tid_addr);
2233}
2234#else
2235static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2236{
2237 return -EINVAL;
2238}
2239#endif
2240
2241static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2242{
2243 /*
2244 * If task has has_child_subreaper - all its descendants
2245 * already have these flag too and new descendants will
2246 * inherit it on fork, skip them.
2247 *
2248 * If we've found child_reaper - skip descendants in
2249 * it's subtree as they will never get out pidns.
2250 */
2251 if (p->signal->has_child_subreaper ||
2252 is_child_reaper(task_pid(p)))
2253 return 0;
2254
2255 p->signal->has_child_subreaper = 1;
2256 return 1;
2257}
2258
2259int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
2260{
2261 return -EINVAL;
2262}
2263
2264int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2265 unsigned long ctrl)
2266{
2267 return -EINVAL;
2268}
2269
2270#define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
2271
2272#ifdef CONFIG_ANON_VMA_NAME
2273
2274#define ANON_VMA_NAME_MAX_LEN 80
2275#define ANON_VMA_NAME_INVALID_CHARS "\\`$[]"
2276
2277static inline bool is_valid_name_char(char ch)
2278{
2279 /* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */
2280 return ch > 0x1f && ch < 0x7f &&
2281 !strchr(ANON_VMA_NAME_INVALID_CHARS, ch);
2282}
2283
2284static int prctl_set_vma(unsigned long opt, unsigned long addr,
2285 unsigned long size, unsigned long arg)
2286{
2287 struct mm_struct *mm = current->mm;
2288 const char __user *uname;
2289 char *name, *pch;
2290 int error;
2291
2292 switch (opt) {
2293 case PR_SET_VMA_ANON_NAME:
2294 uname = (const char __user *)arg;
2295 if (uname) {
2296 name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN);
2297
2298 if (IS_ERR(name))
2299 return PTR_ERR(name);
2300
2301 for (pch = name; *pch != '\0'; pch++) {
2302 if (!is_valid_name_char(*pch)) {
2303 kfree(name);
2304 return -EINVAL;
2305 }
2306 }
2307 } else {
2308 /* Reset the name */
2309 name = NULL;
2310 }
2311
2312 mmap_write_lock(mm);
2313 error = madvise_set_anon_name(mm, addr, size, name);
2314 mmap_write_unlock(mm);
2315 kfree(name);
2316 break;
2317 default:
2318 error = -EINVAL;
2319 }
2320
2321 return error;
2322}
2323
2324#else /* CONFIG_ANON_VMA_NAME */
2325static int prctl_set_vma(unsigned long opt, unsigned long start,
2326 unsigned long size, unsigned long arg)
2327{
2328 return -EINVAL;
2329}
2330#endif /* CONFIG_ANON_VMA_NAME */
2331
2332SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2333 unsigned long, arg4, unsigned long, arg5)
2334{
2335 struct task_struct *me = current;
2336 unsigned char comm[sizeof(me->comm)];
2337 long error;
2338
2339 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2340 if (error != -ENOSYS)
2341 return error;
2342
2343 error = 0;
2344 switch (option) {
2345 case PR_SET_PDEATHSIG:
2346 if (!valid_signal(arg2)) {
2347 error = -EINVAL;
2348 break;
2349 }
2350 me->pdeath_signal = arg2;
2351 break;
2352 case PR_GET_PDEATHSIG:
2353 error = put_user(me->pdeath_signal, (int __user *)arg2);
2354 break;
2355 case PR_GET_DUMPABLE:
2356 error = get_dumpable(me->mm);
2357 break;
2358 case PR_SET_DUMPABLE:
2359 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2360 error = -EINVAL;
2361 break;
2362 }
2363 set_dumpable(me->mm, arg2);
2364 break;
2365
2366 case PR_SET_UNALIGN:
2367 error = SET_UNALIGN_CTL(me, arg2);
2368 break;
2369 case PR_GET_UNALIGN:
2370 error = GET_UNALIGN_CTL(me, arg2);
2371 break;
2372 case PR_SET_FPEMU:
2373 error = SET_FPEMU_CTL(me, arg2);
2374 break;
2375 case PR_GET_FPEMU:
2376 error = GET_FPEMU_CTL(me, arg2);
2377 break;
2378 case PR_SET_FPEXC:
2379 error = SET_FPEXC_CTL(me, arg2);
2380 break;
2381 case PR_GET_FPEXC:
2382 error = GET_FPEXC_CTL(me, arg2);
2383 break;
2384 case PR_GET_TIMING:
2385 error = PR_TIMING_STATISTICAL;
2386 break;
2387 case PR_SET_TIMING:
2388 if (arg2 != PR_TIMING_STATISTICAL)
2389 error = -EINVAL;
2390 break;
2391 case PR_SET_NAME:
2392 comm[sizeof(me->comm) - 1] = 0;
2393 if (strncpy_from_user(comm, (char __user *)arg2,
2394 sizeof(me->comm) - 1) < 0)
2395 return -EFAULT;
2396 set_task_comm(me, comm);
2397 proc_comm_connector(me);
2398 break;
2399 case PR_GET_NAME:
2400 get_task_comm(comm, me);
2401 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2402 return -EFAULT;
2403 break;
2404 case PR_GET_ENDIAN:
2405 error = GET_ENDIAN(me, arg2);
2406 break;
2407 case PR_SET_ENDIAN:
2408 error = SET_ENDIAN(me, arg2);
2409 break;
2410 case PR_GET_SECCOMP:
2411 error = prctl_get_seccomp();
2412 break;
2413 case PR_SET_SECCOMP:
2414 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2415 break;
2416 case PR_GET_TSC:
2417 error = GET_TSC_CTL(arg2);
2418 break;
2419 case PR_SET_TSC:
2420 error = SET_TSC_CTL(arg2);
2421 break;
2422 case PR_TASK_PERF_EVENTS_DISABLE:
2423 error = perf_event_task_disable();
2424 break;
2425 case PR_TASK_PERF_EVENTS_ENABLE:
2426 error = perf_event_task_enable();
2427 break;
2428 case PR_GET_TIMERSLACK:
2429 if (current->timer_slack_ns > ULONG_MAX)
2430 error = ULONG_MAX;
2431 else
2432 error = current->timer_slack_ns;
2433 break;
2434 case PR_SET_TIMERSLACK:
2435 if (arg2 <= 0)
2436 current->timer_slack_ns =
2437 current->default_timer_slack_ns;
2438 else
2439 current->timer_slack_ns = arg2;
2440 break;
2441 case PR_MCE_KILL:
2442 if (arg4 | arg5)
2443 return -EINVAL;
2444 switch (arg2) {
2445 case PR_MCE_KILL_CLEAR:
2446 if (arg3 != 0)
2447 return -EINVAL;
2448 current->flags &= ~PF_MCE_PROCESS;
2449 break;
2450 case PR_MCE_KILL_SET:
2451 current->flags |= PF_MCE_PROCESS;
2452 if (arg3 == PR_MCE_KILL_EARLY)
2453 current->flags |= PF_MCE_EARLY;
2454 else if (arg3 == PR_MCE_KILL_LATE)
2455 current->flags &= ~PF_MCE_EARLY;
2456 else if (arg3 == PR_MCE_KILL_DEFAULT)
2457 current->flags &=
2458 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2459 else
2460 return -EINVAL;
2461 break;
2462 default:
2463 return -EINVAL;
2464 }
2465 break;
2466 case PR_MCE_KILL_GET:
2467 if (arg2 | arg3 | arg4 | arg5)
2468 return -EINVAL;
2469 if (current->flags & PF_MCE_PROCESS)
2470 error = (current->flags & PF_MCE_EARLY) ?
2471 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2472 else
2473 error = PR_MCE_KILL_DEFAULT;
2474 break;
2475 case PR_SET_MM:
2476 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2477 break;
2478 case PR_GET_TID_ADDRESS:
2479 error = prctl_get_tid_address(me, (int __user * __user *)arg2);
2480 break;
2481 case PR_SET_CHILD_SUBREAPER:
2482 me->signal->is_child_subreaper = !!arg2;
2483 if (!arg2)
2484 break;
2485
2486 walk_process_tree(me, propagate_has_child_subreaper, NULL);
2487 break;
2488 case PR_GET_CHILD_SUBREAPER:
2489 error = put_user(me->signal->is_child_subreaper,
2490 (int __user *)arg2);
2491 break;
2492 case PR_SET_NO_NEW_PRIVS:
2493 if (arg2 != 1 || arg3 || arg4 || arg5)
2494 return -EINVAL;
2495
2496 task_set_no_new_privs(current);
2497 break;
2498 case PR_GET_NO_NEW_PRIVS:
2499 if (arg2 || arg3 || arg4 || arg5)
2500 return -EINVAL;
2501 return task_no_new_privs(current) ? 1 : 0;
2502 case PR_GET_THP_DISABLE:
2503 if (arg2 || arg3 || arg4 || arg5)
2504 return -EINVAL;
2505 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
2506 break;
2507 case PR_SET_THP_DISABLE:
2508 if (arg3 || arg4 || arg5)
2509 return -EINVAL;
2510 if (mmap_write_lock_killable(me->mm))
2511 return -EINTR;
2512 if (arg2)
2513 set_bit(MMF_DISABLE_THP, &me->mm->flags);
2514 else
2515 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
2516 mmap_write_unlock(me->mm);
2517 break;
2518 case PR_MPX_ENABLE_MANAGEMENT:
2519 case PR_MPX_DISABLE_MANAGEMENT:
2520 /* No longer implemented: */
2521 return -EINVAL;
2522 case PR_SET_FP_MODE:
2523 error = SET_FP_MODE(me, arg2);
2524 break;
2525 case PR_GET_FP_MODE:
2526 error = GET_FP_MODE(me);
2527 break;
2528 case PR_SVE_SET_VL:
2529 error = SVE_SET_VL(arg2);
2530 break;
2531 case PR_SVE_GET_VL:
2532 error = SVE_GET_VL();
2533 break;
2534 case PR_GET_SPECULATION_CTRL:
2535 if (arg3 || arg4 || arg5)
2536 return -EINVAL;
2537 error = arch_prctl_spec_ctrl_get(me, arg2);
2538 break;
2539 case PR_SET_SPECULATION_CTRL:
2540 if (arg4 || arg5)
2541 return -EINVAL;
2542 error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
2543 break;
2544 case PR_PAC_RESET_KEYS:
2545 if (arg3 || arg4 || arg5)
2546 return -EINVAL;
2547 error = PAC_RESET_KEYS(me, arg2);
2548 break;
2549 case PR_PAC_SET_ENABLED_KEYS:
2550 if (arg4 || arg5)
2551 return -EINVAL;
2552 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3);
2553 break;
2554 case PR_PAC_GET_ENABLED_KEYS:
2555 if (arg2 || arg3 || arg4 || arg5)
2556 return -EINVAL;
2557 error = PAC_GET_ENABLED_KEYS(me);
2558 break;
2559 case PR_SET_TAGGED_ADDR_CTRL:
2560 if (arg3 || arg4 || arg5)
2561 return -EINVAL;
2562 error = SET_TAGGED_ADDR_CTRL(arg2);
2563 break;
2564 case PR_GET_TAGGED_ADDR_CTRL:
2565 if (arg2 || arg3 || arg4 || arg5)
2566 return -EINVAL;
2567 error = GET_TAGGED_ADDR_CTRL();
2568 break;
2569 case PR_SET_IO_FLUSHER:
2570 if (!capable(CAP_SYS_RESOURCE))
2571 return -EPERM;
2572
2573 if (arg3 || arg4 || arg5)
2574 return -EINVAL;
2575
2576 if (arg2 == 1)
2577 current->flags |= PR_IO_FLUSHER;
2578 else if (!arg2)
2579 current->flags &= ~PR_IO_FLUSHER;
2580 else
2581 return -EINVAL;
2582 break;
2583 case PR_GET_IO_FLUSHER:
2584 if (!capable(CAP_SYS_RESOURCE))
2585 return -EPERM;
2586
2587 if (arg2 || arg3 || arg4 || arg5)
2588 return -EINVAL;
2589
2590 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
2591 break;
2592 case PR_SET_SYSCALL_USER_DISPATCH:
2593 error = set_syscall_user_dispatch(arg2, arg3, arg4,
2594 (char __user *) arg5);
2595 break;
2596#ifdef CONFIG_SCHED_CORE
2597 case PR_SCHED_CORE:
2598 error = sched_core_share_pid(arg2, arg3, arg4, arg5);
2599 break;
2600#endif
2601 case PR_SET_VMA:
2602 error = prctl_set_vma(arg2, arg3, arg4, arg5);
2603 break;
2604 default:
2605 error = -EINVAL;
2606 break;
2607 }
2608 return error;
2609}
2610
2611SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2612 struct getcpu_cache __user *, unused)
2613{
2614 int err = 0;
2615 int cpu = raw_smp_processor_id();
2616
2617 if (cpup)
2618 err |= put_user(cpu, cpup);
2619 if (nodep)
2620 err |= put_user(cpu_to_node(cpu), nodep);
2621 return err ? -EFAULT : 0;
2622}
2623
2624/**
2625 * do_sysinfo - fill in sysinfo struct
2626 * @info: pointer to buffer to fill
2627 */
2628static int do_sysinfo(struct sysinfo *info)
2629{
2630 unsigned long mem_total, sav_total;
2631 unsigned int mem_unit, bitcount;
2632 struct timespec64 tp;
2633
2634 memset(info, 0, sizeof(struct sysinfo));
2635
2636 ktime_get_boottime_ts64(&tp);
2637 timens_add_boottime(&tp);
2638 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2639
2640 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2641
2642 info->procs = nr_threads;
2643
2644 si_meminfo(info);
2645 si_swapinfo(info);
2646
2647 /*
2648 * If the sum of all the available memory (i.e. ram + swap)
2649 * is less than can be stored in a 32 bit unsigned long then
2650 * we can be binary compatible with 2.2.x kernels. If not,
2651 * well, in that case 2.2.x was broken anyways...
2652 *
2653 * -Erik Andersen <[email protected]>
2654 */
2655
2656 mem_total = info->totalram + info->totalswap;
2657 if (mem_total < info->totalram || mem_total < info->totalswap)
2658 goto out;
2659 bitcount = 0;
2660 mem_unit = info->mem_unit;
2661 while (mem_unit > 1) {
2662 bitcount++;
2663 mem_unit >>= 1;
2664 sav_total = mem_total;
2665 mem_total <<= 1;
2666 if (mem_total < sav_total)
2667 goto out;
2668 }
2669
2670 /*
2671 * If mem_total did not overflow, multiply all memory values by
2672 * info->mem_unit and set it to 1. This leaves things compatible
2673 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2674 * kernels...
2675 */
2676
2677 info->mem_unit = 1;
2678 info->totalram <<= bitcount;
2679 info->freeram <<= bitcount;
2680 info->sharedram <<= bitcount;
2681 info->bufferram <<= bitcount;
2682 info->totalswap <<= bitcount;
2683 info->freeswap <<= bitcount;
2684 info->totalhigh <<= bitcount;
2685 info->freehigh <<= bitcount;
2686
2687out:
2688 return 0;
2689}
2690
2691SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2692{
2693 struct sysinfo val;
2694
2695 do_sysinfo(&val);
2696
2697 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2698 return -EFAULT;
2699
2700 return 0;
2701}
2702
2703#ifdef CONFIG_COMPAT
2704struct compat_sysinfo {
2705 s32 uptime;
2706 u32 loads[3];
2707 u32 totalram;
2708 u32 freeram;
2709 u32 sharedram;
2710 u32 bufferram;
2711 u32 totalswap;
2712 u32 freeswap;
2713 u16 procs;
2714 u16 pad;
2715 u32 totalhigh;
2716 u32 freehigh;
2717 u32 mem_unit;
2718 char _f[20-2*sizeof(u32)-sizeof(int)];
2719};
2720
2721COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2722{
2723 struct sysinfo s;
2724 struct compat_sysinfo s_32;
2725
2726 do_sysinfo(&s);
2727
2728 /* Check to see if any memory value is too large for 32-bit and scale
2729 * down if needed
2730 */
2731 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2732 int bitcount = 0;
2733
2734 while (s.mem_unit < PAGE_SIZE) {
2735 s.mem_unit <<= 1;
2736 bitcount++;
2737 }
2738
2739 s.totalram >>= bitcount;
2740 s.freeram >>= bitcount;
2741 s.sharedram >>= bitcount;
2742 s.bufferram >>= bitcount;
2743 s.totalswap >>= bitcount;
2744 s.freeswap >>= bitcount;
2745 s.totalhigh >>= bitcount;
2746 s.freehigh >>= bitcount;
2747 }
2748
2749 memset(&s_32, 0, sizeof(s_32));
2750 s_32.uptime = s.uptime;
2751 s_32.loads[0] = s.loads[0];
2752 s_32.loads[1] = s.loads[1];
2753 s_32.loads[2] = s.loads[2];
2754 s_32.totalram = s.totalram;
2755 s_32.freeram = s.freeram;
2756 s_32.sharedram = s.sharedram;
2757 s_32.bufferram = s.bufferram;
2758 s_32.totalswap = s.totalswap;
2759 s_32.freeswap = s.freeswap;
2760 s_32.procs = s.procs;
2761 s_32.totalhigh = s.totalhigh;
2762 s_32.freehigh = s.freehigh;
2763 s_32.mem_unit = s.mem_unit;
2764 if (copy_to_user(info, &s_32, sizeof(s_32)))
2765 return -EFAULT;
2766 return 0;
2767}
2768#endif /* CONFIG_COMPAT */