projects/linux·blob v5.10-rc6 · refs

2697 lines · 62.9 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/dcookies.h>
28#include <linux/suspend.h>
29#include <linux/tty.h>
30#include <linux/signal.h>
31#include <linux/cn_proc.h>
32#include <linux/getcpu.h>
33#include <linux/task_io_accounting_ops.h>
34#include <linux/seccomp.h>
35#include <linux/cpu.h>
36#include <linux/personality.h>
37#include <linux/ptrace.h>
38#include <linux/fs_struct.h>
39#include <linux/file.h>
40#include <linux/mount.h>
41#include <linux/gfp.h>
42#include <linux/syscore_ops.h>
43#include <linux/version.h>
44#include <linux/ctype.h>
45
46#include <linux/compat.h>
47#include <linux/syscalls.h>
48#include <linux/kprobes.h>
49#include <linux/user_namespace.h>
50#include <linux/time_namespace.h>
51#include <linux/binfmts.h>
52
53#include <linux/sched.h>
54#include <linux/sched/autogroup.h>
55#include <linux/sched/loadavg.h>
56#include <linux/sched/stat.h>
57#include <linux/sched/mm.h>
58#include <linux/sched/coredump.h>
59#include <linux/sched/task.h>
60#include <linux/sched/cputime.h>
61#include <linux/rcupdate.h>
62#include <linux/uidgid.h>
63#include <linux/cred.h>
64
65#include <linux/nospec.h>
66
67#include <linux/kmsg_dump.h>
68/* Move somewhere else to avoid recompiling? */
69#include <generated/utsrelease.h>
70
71#include <linux/uaccess.h>
72#include <asm/io.h>
73#include <asm/unistd.h>
74
75#include "uid16.h"
76
77#ifndef SET_UNALIGN_CTL
78# define SET_UNALIGN_CTL(a, b) (-EINVAL)
79#endif
80#ifndef GET_UNALIGN_CTL
81# define GET_UNALIGN_CTL(a, b) (-EINVAL)
82#endif
83#ifndef SET_FPEMU_CTL
84# define SET_FPEMU_CTL(a, b) (-EINVAL)
85#endif
86#ifndef GET_FPEMU_CTL
87# define GET_FPEMU_CTL(a, b) (-EINVAL)
88#endif
89#ifndef SET_FPEXC_CTL
90# define SET_FPEXC_CTL(a, b) (-EINVAL)
91#endif
92#ifndef GET_FPEXC_CTL
93# define GET_FPEXC_CTL(a, b) (-EINVAL)
94#endif
95#ifndef GET_ENDIAN
96# define GET_ENDIAN(a, b) (-EINVAL)
97#endif
98#ifndef SET_ENDIAN
99# define SET_ENDIAN(a, b) (-EINVAL)
100#endif
101#ifndef GET_TSC_CTL
102# define GET_TSC_CTL(a) (-EINVAL)
103#endif
104#ifndef SET_TSC_CTL
105# define SET_TSC_CTL(a) (-EINVAL)
106#endif
107#ifndef GET_FP_MODE
108# define GET_FP_MODE(a) (-EINVAL)
109#endif
110#ifndef SET_FP_MODE
111# define SET_FP_MODE(a,b) (-EINVAL)
112#endif
113#ifndef SVE_SET_VL
114# define SVE_SET_VL(a) (-EINVAL)
115#endif
116#ifndef SVE_GET_VL
117# define SVE_GET_VL() (-EINVAL)
118#endif
119#ifndef PAC_RESET_KEYS
120# define PAC_RESET_KEYS(a, b) (-EINVAL)
121#endif
122#ifndef SET_TAGGED_ADDR_CTRL
123# define SET_TAGGED_ADDR_CTRL(a) (-EINVAL)
124#endif
125#ifndef GET_TAGGED_ADDR_CTRL
126# define GET_TAGGED_ADDR_CTRL() (-EINVAL)
127#endif
128
129/*
130 * this is where the system-wide overflow UID and GID are defined, for
131 * architectures that now have 32-bit UID/GID but didn't in the past
132 */
133
134int overflowuid = DEFAULT_OVERFLOWUID;
135int overflowgid = DEFAULT_OVERFLOWGID;
136
137EXPORT_SYMBOL(overflowuid);
138EXPORT_SYMBOL(overflowgid);
139
140/*
141 * the same as above, but for filesystems which can only store a 16-bit
142 * UID and GID. as such, this is needed on all architectures
143 */
144
145int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
146int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
147
148EXPORT_SYMBOL(fs_overflowuid);
149EXPORT_SYMBOL(fs_overflowgid);
150
151/*
152 * Returns true if current's euid is same as p's uid or euid,
153 * or has CAP_SYS_NICE to p's user_ns.
154 *
155 * Called with rcu_read_lock, creds are safe
156 */
157static bool set_one_prio_perm(struct task_struct *p)
158{
159 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
160
161 if (uid_eq(pcred->uid, cred->euid) ||
162 uid_eq(pcred->euid, cred->euid))
163 return true;
164 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
165 return true;
166 return false;
167}
168
169/*
170 * set the priority of a task
171 * - the caller must hold the RCU read lock
172 */
173static int set_one_prio(struct task_struct *p, int niceval, int error)
174{
175 int no_nice;
176
177 if (!set_one_prio_perm(p)) {
178 error = -EPERM;
179 goto out;
180 }
181 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
182 error = -EACCES;
183 goto out;
184 }
185 no_nice = security_task_setnice(p, niceval);
186 if (no_nice) {
187 error = no_nice;
188 goto out;
189 }
190 if (error == -ESRCH)
191 error = 0;
192 set_user_nice(p, niceval);
193out:
194 return error;
195}
196
197SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
198{
199 struct task_struct *g, *p;
200 struct user_struct *user;
201 const struct cred *cred = current_cred();
202 int error = -EINVAL;
203 struct pid *pgrp;
204 kuid_t uid;
205
206 if (which > PRIO_USER || which < PRIO_PROCESS)
207 goto out;
208
209 /* normalize: avoid signed division (rounding problems) */
210 error = -ESRCH;
211 if (niceval < MIN_NICE)
212 niceval = MIN_NICE;
213 if (niceval > MAX_NICE)
214 niceval = MAX_NICE;
215
216 rcu_read_lock();
217 read_lock(&tasklist_lock);
218 switch (which) {
219 case PRIO_PROCESS:
220 if (who)
221 p = find_task_by_vpid(who);
222 else
223 p = current;
224 if (p)
225 error = set_one_prio(p, niceval, error);
226 break;
227 case PRIO_PGRP:
228 if (who)
229 pgrp = find_vpid(who);
230 else
231 pgrp = task_pgrp(current);
232 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
233 error = set_one_prio(p, niceval, error);
234 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
235 break;
236 case PRIO_USER:
237 uid = make_kuid(cred->user_ns, who);
238 user = cred->user;
239 if (!who)
240 uid = cred->uid;
241 else if (!uid_eq(uid, cred->uid)) {
242 user = find_user(uid);
243 if (!user)
244 goto out_unlock; /* No processes for this user */
245 }
246 do_each_thread(g, p) {
247 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
248 error = set_one_prio(p, niceval, error);
249 } while_each_thread(g, p);
250 if (!uid_eq(uid, cred->uid))
251 free_uid(user); /* For find_user() */
252 break;
253 }
254out_unlock:
255 read_unlock(&tasklist_lock);
256 rcu_read_unlock();
257out:
258 return error;
259}
260
261/*
262 * Ugh. To avoid negative return values, "getpriority()" will
263 * not return the normal nice-value, but a negated value that
264 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
265 * to stay compatible.
266 */
267SYSCALL_DEFINE2(getpriority, int, which, int, who)
268{
269 struct task_struct *g, *p;
270 struct user_struct *user;
271 const struct cred *cred = current_cred();
272 long niceval, retval = -ESRCH;
273 struct pid *pgrp;
274 kuid_t uid;
275
276 if (which > PRIO_USER || which < PRIO_PROCESS)
277 return -EINVAL;
278
279 rcu_read_lock();
280 read_lock(&tasklist_lock);
281 switch (which) {
282 case PRIO_PROCESS:
283 if (who)
284 p = find_task_by_vpid(who);
285 else
286 p = current;
287 if (p) {
288 niceval = nice_to_rlimit(task_nice(p));
289 if (niceval > retval)
290 retval = niceval;
291 }
292 break;
293 case PRIO_PGRP:
294 if (who)
295 pgrp = find_vpid(who);
296 else
297 pgrp = task_pgrp(current);
298 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
299 niceval = nice_to_rlimit(task_nice(p));
300 if (niceval > retval)
301 retval = niceval;
302 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
303 break;
304 case PRIO_USER:
305 uid = make_kuid(cred->user_ns, who);
306 user = cred->user;
307 if (!who)
308 uid = cred->uid;
309 else if (!uid_eq(uid, cred->uid)) {
310 user = find_user(uid);
311 if (!user)
312 goto out_unlock; /* No processes for this user */
313 }
314 do_each_thread(g, p) {
315 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
316 niceval = nice_to_rlimit(task_nice(p));
317 if (niceval > retval)
318 retval = niceval;
319 }
320 } while_each_thread(g, p);
321 if (!uid_eq(uid, cred->uid))
322 free_uid(user); /* for find_user() */
323 break;
324 }
325out_unlock:
326 read_unlock(&tasklist_lock);
327 rcu_read_unlock();
328
329 return retval;
330}
331
332/*
333 * Unprivileged users may change the real gid to the effective gid
334 * or vice versa. (BSD-style)
335 *
336 * If you set the real gid at all, or set the effective gid to a value not
337 * equal to the real gid, then the saved gid is set to the new effective gid.
338 *
339 * This makes it possible for a setgid program to completely drop its
340 * privileges, which is often a useful assertion to make when you are doing
341 * a security audit over a program.
342 *
343 * The general idea is that a program which uses just setregid() will be
344 * 100% compatible with BSD. A program which uses just setgid() will be
345 * 100% compatible with POSIX with saved IDs.
346 *
347 * SMP: There are not races, the GIDs are checked only by filesystem
348 * operations (as far as semantic preservation is concerned).
349 */
350#ifdef CONFIG_MULTIUSER
351long __sys_setregid(gid_t rgid, gid_t egid)
352{
353 struct user_namespace *ns = current_user_ns();
354 const struct cred *old;
355 struct cred *new;
356 int retval;
357 kgid_t krgid, kegid;
358
359 krgid = make_kgid(ns, rgid);
360 kegid = make_kgid(ns, egid);
361
362 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
363 return -EINVAL;
364 if ((egid != (gid_t) -1) && !gid_valid(kegid))
365 return -EINVAL;
366
367 new = prepare_creds();
368 if (!new)
369 return -ENOMEM;
370 old = current_cred();
371
372 retval = -EPERM;
373 if (rgid != (gid_t) -1) {
374 if (gid_eq(old->gid, krgid) ||
375 gid_eq(old->egid, krgid) ||
376 ns_capable_setid(old->user_ns, CAP_SETGID))
377 new->gid = krgid;
378 else
379 goto error;
380 }
381 if (egid != (gid_t) -1) {
382 if (gid_eq(old->gid, kegid) ||
383 gid_eq(old->egid, kegid) ||
384 gid_eq(old->sgid, kegid) ||
385 ns_capable_setid(old->user_ns, CAP_SETGID))
386 new->egid = kegid;
387 else
388 goto error;
389 }
390
391 if (rgid != (gid_t) -1 ||
392 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
393 new->sgid = new->egid;
394 new->fsgid = new->egid;
395
396 retval = security_task_fix_setgid(new, old, LSM_SETID_RE);
397 if (retval < 0)
398 goto error;
399
400 return commit_creds(new);
401
402error:
403 abort_creds(new);
404 return retval;
405}
406
407SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
408{
409 return __sys_setregid(rgid, egid);
410}
411
412/*
413 * setgid() is implemented like SysV w/ SAVED_IDS
414 *
415 * SMP: Same implicit races as above.
416 */
417long __sys_setgid(gid_t gid)
418{
419 struct user_namespace *ns = current_user_ns();
420 const struct cred *old;
421 struct cred *new;
422 int retval;
423 kgid_t kgid;
424
425 kgid = make_kgid(ns, gid);
426 if (!gid_valid(kgid))
427 return -EINVAL;
428
429 new = prepare_creds();
430 if (!new)
431 return -ENOMEM;
432 old = current_cred();
433
434 retval = -EPERM;
435 if (ns_capable_setid(old->user_ns, CAP_SETGID))
436 new->gid = new->egid = new->sgid = new->fsgid = kgid;
437 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
438 new->egid = new->fsgid = kgid;
439 else
440 goto error;
441
442 retval = security_task_fix_setgid(new, old, LSM_SETID_ID);
443 if (retval < 0)
444 goto error;
445
446 return commit_creds(new);
447
448error:
449 abort_creds(new);
450 return retval;
451}
452
453SYSCALL_DEFINE1(setgid, gid_t, gid)
454{
455 return __sys_setgid(gid);
456}
457
458/*
459 * change the user struct in a credentials set to match the new UID
460 */
461static int set_user(struct cred *new)
462{
463 struct user_struct *new_user;
464
465 new_user = alloc_uid(new->uid);
466 if (!new_user)
467 return -EAGAIN;
468
469 /*
470 * We don't fail in case of NPROC limit excess here because too many
471 * poorly written programs don't check set*uid() return code, assuming
472 * it never fails if called by root. We may still enforce NPROC limit
473 * for programs doing set*uid()+execve() by harmlessly deferring the
474 * failure to the execve() stage.
475 */
476 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
477 new_user != INIT_USER)
478 current->flags |= PF_NPROC_EXCEEDED;
479 else
480 current->flags &= ~PF_NPROC_EXCEEDED;
481
482 free_uid(new->user);
483 new->user = new_user;
484 return 0;
485}
486
487/*
488 * Unprivileged users may change the real uid to the effective uid
489 * or vice versa. (BSD-style)
490 *
491 * If you set the real uid at all, or set the effective uid to a value not
492 * equal to the real uid, then the saved uid is set to the new effective uid.
493 *
494 * This makes it possible for a setuid program to completely drop its
495 * privileges, which is often a useful assertion to make when you are doing
496 * a security audit over a program.
497 *
498 * The general idea is that a program which uses just setreuid() will be
499 * 100% compatible with BSD. A program which uses just setuid() will be
500 * 100% compatible with POSIX with saved IDs.
501 */
502long __sys_setreuid(uid_t ruid, uid_t euid)
503{
504 struct user_namespace *ns = current_user_ns();
505 const struct cred *old;
506 struct cred *new;
507 int retval;
508 kuid_t kruid, keuid;
509
510 kruid = make_kuid(ns, ruid);
511 keuid = make_kuid(ns, euid);
512
513 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
514 return -EINVAL;
515 if ((euid != (uid_t) -1) && !uid_valid(keuid))
516 return -EINVAL;
517
518 new = prepare_creds();
519 if (!new)
520 return -ENOMEM;
521 old = current_cred();
522
523 retval = -EPERM;
524 if (ruid != (uid_t) -1) {
525 new->uid = kruid;
526 if (!uid_eq(old->uid, kruid) &&
527 !uid_eq(old->euid, kruid) &&
528 !ns_capable_setid(old->user_ns, CAP_SETUID))
529 goto error;
530 }
531
532 if (euid != (uid_t) -1) {
533 new->euid = keuid;
534 if (!uid_eq(old->uid, keuid) &&
535 !uid_eq(old->euid, keuid) &&
536 !uid_eq(old->suid, keuid) &&
537 !ns_capable_setid(old->user_ns, CAP_SETUID))
538 goto error;
539 }
540
541 if (!uid_eq(new->uid, old->uid)) {
542 retval = set_user(new);
543 if (retval < 0)
544 goto error;
545 }
546 if (ruid != (uid_t) -1 ||
547 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
548 new->suid = new->euid;
549 new->fsuid = new->euid;
550
551 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
552 if (retval < 0)
553 goto error;
554
555 return commit_creds(new);
556
557error:
558 abort_creds(new);
559 return retval;
560}
561
562SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
563{
564 return __sys_setreuid(ruid, euid);
565}
566
567/*
568 * setuid() is implemented like SysV with SAVED_IDS
569 *
570 * Note that SAVED_ID's is deficient in that a setuid root program
571 * like sendmail, for example, cannot set its uid to be a normal
572 * user and then switch back, because if you're root, setuid() sets
573 * the saved uid too. If you don't like this, blame the bright people
574 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
575 * will allow a root program to temporarily drop privileges and be able to
576 * regain them by swapping the real and effective uid.
577 */
578long __sys_setuid(uid_t uid)
579{
580 struct user_namespace *ns = current_user_ns();
581 const struct cred *old;
582 struct cred *new;
583 int retval;
584 kuid_t kuid;
585
586 kuid = make_kuid(ns, uid);
587 if (!uid_valid(kuid))
588 return -EINVAL;
589
590 new = prepare_creds();
591 if (!new)
592 return -ENOMEM;
593 old = current_cred();
594
595 retval = -EPERM;
596 if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
597 new->suid = new->uid = kuid;
598 if (!uid_eq(kuid, old->uid)) {
599 retval = set_user(new);
600 if (retval < 0)
601 goto error;
602 }
603 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
604 goto error;
605 }
606
607 new->fsuid = new->euid = kuid;
608
609 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
610 if (retval < 0)
611 goto error;
612
613 return commit_creds(new);
614
615error:
616 abort_creds(new);
617 return retval;
618}
619
620SYSCALL_DEFINE1(setuid, uid_t, uid)
621{
622 return __sys_setuid(uid);
623}
624
625
626/*
627 * This function implements a generic ability to update ruid, euid,
628 * and suid. This allows you to implement the 4.4 compatible seteuid().
629 */
630long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
631{
632 struct user_namespace *ns = current_user_ns();
633 const struct cred *old;
634 struct cred *new;
635 int retval;
636 kuid_t kruid, keuid, ksuid;
637
638 kruid = make_kuid(ns, ruid);
639 keuid = make_kuid(ns, euid);
640 ksuid = make_kuid(ns, suid);
641
642 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
643 return -EINVAL;
644
645 if ((euid != (uid_t) -1) && !uid_valid(keuid))
646 return -EINVAL;
647
648 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
649 return -EINVAL;
650
651 new = prepare_creds();
652 if (!new)
653 return -ENOMEM;
654
655 old = current_cred();
656
657 retval = -EPERM;
658 if (!ns_capable_setid(old->user_ns, CAP_SETUID)) {
659 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
660 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
661 goto error;
662 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
663 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
664 goto error;
665 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
666 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
667 goto error;
668 }
669
670 if (ruid != (uid_t) -1) {
671 new->uid = kruid;
672 if (!uid_eq(kruid, old->uid)) {
673 retval = set_user(new);
674 if (retval < 0)
675 goto error;
676 }
677 }
678 if (euid != (uid_t) -1)
679 new->euid = keuid;
680 if (suid != (uid_t) -1)
681 new->suid = ksuid;
682 new->fsuid = new->euid;
683
684 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
685 if (retval < 0)
686 goto error;
687
688 return commit_creds(new);
689
690error:
691 abort_creds(new);
692 return retval;
693}
694
695SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
696{
697 return __sys_setresuid(ruid, euid, suid);
698}
699
700SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
701{
702 const struct cred *cred = current_cred();
703 int retval;
704 uid_t ruid, euid, suid;
705
706 ruid = from_kuid_munged(cred->user_ns, cred->uid);
707 euid = from_kuid_munged(cred->user_ns, cred->euid);
708 suid = from_kuid_munged(cred->user_ns, cred->suid);
709
710 retval = put_user(ruid, ruidp);
711 if (!retval) {
712 retval = put_user(euid, euidp);
713 if (!retval)
714 return put_user(suid, suidp);
715 }
716 return retval;
717}
718
719/*
720 * Same as above, but for rgid, egid, sgid.
721 */
722long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
723{
724 struct user_namespace *ns = current_user_ns();
725 const struct cred *old;
726 struct cred *new;
727 int retval;
728 kgid_t krgid, kegid, ksgid;
729
730 krgid = make_kgid(ns, rgid);
731 kegid = make_kgid(ns, egid);
732 ksgid = make_kgid(ns, sgid);
733
734 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
735 return -EINVAL;
736 if ((egid != (gid_t) -1) && !gid_valid(kegid))
737 return -EINVAL;
738 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
739 return -EINVAL;
740
741 new = prepare_creds();
742 if (!new)
743 return -ENOMEM;
744 old = current_cred();
745
746 retval = -EPERM;
747 if (!ns_capable_setid(old->user_ns, CAP_SETGID)) {
748 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
749 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
750 goto error;
751 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
752 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
753 goto error;
754 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
755 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
756 goto error;
757 }
758
759 if (rgid != (gid_t) -1)
760 new->gid = krgid;
761 if (egid != (gid_t) -1)
762 new->egid = kegid;
763 if (sgid != (gid_t) -1)
764 new->sgid = ksgid;
765 new->fsgid = new->egid;
766
767 retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
768 if (retval < 0)
769 goto error;
770
771 return commit_creds(new);
772
773error:
774 abort_creds(new);
775 return retval;
776}
777
778SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
779{
780 return __sys_setresgid(rgid, egid, sgid);
781}
782
783SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
784{
785 const struct cred *cred = current_cred();
786 int retval;
787 gid_t rgid, egid, sgid;
788
789 rgid = from_kgid_munged(cred->user_ns, cred->gid);
790 egid = from_kgid_munged(cred->user_ns, cred->egid);
791 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
792
793 retval = put_user(rgid, rgidp);
794 if (!retval) {
795 retval = put_user(egid, egidp);
796 if (!retval)
797 retval = put_user(sgid, sgidp);
798 }
799
800 return retval;
801}
802
803
804/*
805 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
806 * is used for "access()" and for the NFS daemon (letting nfsd stay at
807 * whatever uid it wants to). It normally shadows "euid", except when
808 * explicitly set by setfsuid() or for access..
809 */
810long __sys_setfsuid(uid_t uid)
811{
812 const struct cred *old;
813 struct cred *new;
814 uid_t old_fsuid;
815 kuid_t kuid;
816
817 old = current_cred();
818 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
819
820 kuid = make_kuid(old->user_ns, uid);
821 if (!uid_valid(kuid))
822 return old_fsuid;
823
824 new = prepare_creds();
825 if (!new)
826 return old_fsuid;
827
828 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
829 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
830 ns_capable_setid(old->user_ns, CAP_SETUID)) {
831 if (!uid_eq(kuid, old->fsuid)) {
832 new->fsuid = kuid;
833 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
834 goto change_okay;
835 }
836 }
837
838 abort_creds(new);
839 return old_fsuid;
840
841change_okay:
842 commit_creds(new);
843 return old_fsuid;
844}
845
846SYSCALL_DEFINE1(setfsuid, uid_t, uid)
847{
848 return __sys_setfsuid(uid);
849}
850
851/*
852 * Samma på svenska..
853 */
854long __sys_setfsgid(gid_t gid)
855{
856 const struct cred *old;
857 struct cred *new;
858 gid_t old_fsgid;
859 kgid_t kgid;
860
861 old = current_cred();
862 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
863
864 kgid = make_kgid(old->user_ns, gid);
865 if (!gid_valid(kgid))
866 return old_fsgid;
867
868 new = prepare_creds();
869 if (!new)
870 return old_fsgid;
871
872 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
873 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
874 ns_capable_setid(old->user_ns, CAP_SETGID)) {
875 if (!gid_eq(kgid, old->fsgid)) {
876 new->fsgid = kgid;
877 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
878 goto change_okay;
879 }
880 }
881
882 abort_creds(new);
883 return old_fsgid;
884
885change_okay:
886 commit_creds(new);
887 return old_fsgid;
888}
889
890SYSCALL_DEFINE1(setfsgid, gid_t, gid)
891{
892 return __sys_setfsgid(gid);
893}
894#endif /* CONFIG_MULTIUSER */
895
896/**
897 * sys_getpid - return the thread group id of the current process
898 *
899 * Note, despite the name, this returns the tgid not the pid. The tgid and
900 * the pid are identical unless CLONE_THREAD was specified on clone() in
901 * which case the tgid is the same in all threads of the same group.
902 *
903 * This is SMP safe as current->tgid does not change.
904 */
905SYSCALL_DEFINE0(getpid)
906{
907 return task_tgid_vnr(current);
908}
909
910/* Thread ID - the internal kernel "pid" */
911SYSCALL_DEFINE0(gettid)
912{
913 return task_pid_vnr(current);
914}
915
916/*
917 * Accessing ->real_parent is not SMP-safe, it could
918 * change from under us. However, we can use a stale
919 * value of ->real_parent under rcu_read_lock(), see
920 * release_task()->call_rcu(delayed_put_task_struct).
921 */
922SYSCALL_DEFINE0(getppid)
923{
924 int pid;
925
926 rcu_read_lock();
927 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
928 rcu_read_unlock();
929
930 return pid;
931}
932
933SYSCALL_DEFINE0(getuid)
934{
935 /* Only we change this so SMP safe */
936 return from_kuid_munged(current_user_ns(), current_uid());
937}
938
939SYSCALL_DEFINE0(geteuid)
940{
941 /* Only we change this so SMP safe */
942 return from_kuid_munged(current_user_ns(), current_euid());
943}
944
945SYSCALL_DEFINE0(getgid)
946{
947 /* Only we change this so SMP safe */
948 return from_kgid_munged(current_user_ns(), current_gid());
949}
950
951SYSCALL_DEFINE0(getegid)
952{
953 /* Only we change this so SMP safe */
954 return from_kgid_munged(current_user_ns(), current_egid());
955}
956
957static void do_sys_times(struct tms *tms)
958{
959 u64 tgutime, tgstime, cutime, cstime;
960
961 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
962 cutime = current->signal->cutime;
963 cstime = current->signal->cstime;
964 tms->tms_utime = nsec_to_clock_t(tgutime);
965 tms->tms_stime = nsec_to_clock_t(tgstime);
966 tms->tms_cutime = nsec_to_clock_t(cutime);
967 tms->tms_cstime = nsec_to_clock_t(cstime);
968}
969
970SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
971{
972 if (tbuf) {
973 struct tms tmp;
974
975 do_sys_times(&tmp);
976 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
977 return -EFAULT;
978 }
979 force_successful_syscall_return();
980 return (long) jiffies_64_to_clock_t(get_jiffies_64());
981}
982
983#ifdef CONFIG_COMPAT
984static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
985{
986 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
987}
988
989COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
990{
991 if (tbuf) {
992 struct tms tms;
993 struct compat_tms tmp;
994
995 do_sys_times(&tms);
996 /* Convert our struct tms to the compat version. */
997 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
998 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
999 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
1000 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
1001 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
1002 return -EFAULT;
1003 }
1004 force_successful_syscall_return();
1005 return compat_jiffies_to_clock_t(jiffies);
1006}
1007#endif
1008
1009/*
1010 * This needs some heavy checking ...
1011 * I just haven't the stomach for it. I also don't fully
1012 * understand sessions/pgrp etc. Let somebody who does explain it.
1013 *
1014 * OK, I think I have the protection semantics right.... this is really
1015 * only important on a multi-user system anyway, to make sure one user
1016 * can't send a signal to a process owned by another. -TYT, 12/12/91
1017 *
1018 * !PF_FORKNOEXEC check to conform completely to POSIX.
1019 */
1020SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1021{
1022 struct task_struct *p;
1023 struct task_struct *group_leader = current->group_leader;
1024 struct pid *pgrp;
1025 int err;
1026
1027 if (!pid)
1028 pid = task_pid_vnr(group_leader);
1029 if (!pgid)
1030 pgid = pid;
1031 if (pgid < 0)
1032 return -EINVAL;
1033 rcu_read_lock();
1034
1035 /* From this point forward we keep holding onto the tasklist lock
1036 * so that our parent does not change from under us. -DaveM
1037 */
1038 write_lock_irq(&tasklist_lock);
1039
1040 err = -ESRCH;
1041 p = find_task_by_vpid(pid);
1042 if (!p)
1043 goto out;
1044
1045 err = -EINVAL;
1046 if (!thread_group_leader(p))
1047 goto out;
1048
1049 if (same_thread_group(p->real_parent, group_leader)) {
1050 err = -EPERM;
1051 if (task_session(p) != task_session(group_leader))
1052 goto out;
1053 err = -EACCES;
1054 if (!(p->flags & PF_FORKNOEXEC))
1055 goto out;
1056 } else {
1057 err = -ESRCH;
1058 if (p != group_leader)
1059 goto out;
1060 }
1061
1062 err = -EPERM;
1063 if (p->signal->leader)
1064 goto out;
1065
1066 pgrp = task_pid(p);
1067 if (pgid != pid) {
1068 struct task_struct *g;
1069
1070 pgrp = find_vpid(pgid);
1071 g = pid_task(pgrp, PIDTYPE_PGID);
1072 if (!g || task_session(g) != task_session(group_leader))
1073 goto out;
1074 }
1075
1076 err = security_task_setpgid(p, pgid);
1077 if (err)
1078 goto out;
1079
1080 if (task_pgrp(p) != pgrp)
1081 change_pid(p, PIDTYPE_PGID, pgrp);
1082
1083 err = 0;
1084out:
1085 /* All paths lead to here, thus we are safe. -DaveM */
1086 write_unlock_irq(&tasklist_lock);
1087 rcu_read_unlock();
1088 return err;
1089}
1090
1091static int do_getpgid(pid_t pid)
1092{
1093 struct task_struct *p;
1094 struct pid *grp;
1095 int retval;
1096
1097 rcu_read_lock();
1098 if (!pid)
1099 grp = task_pgrp(current);
1100 else {
1101 retval = -ESRCH;
1102 p = find_task_by_vpid(pid);
1103 if (!p)
1104 goto out;
1105 grp = task_pgrp(p);
1106 if (!grp)
1107 goto out;
1108
1109 retval = security_task_getpgid(p);
1110 if (retval)
1111 goto out;
1112 }
1113 retval = pid_vnr(grp);
1114out:
1115 rcu_read_unlock();
1116 return retval;
1117}
1118
1119SYSCALL_DEFINE1(getpgid, pid_t, pid)
1120{
1121 return do_getpgid(pid);
1122}
1123
1124#ifdef __ARCH_WANT_SYS_GETPGRP
1125
1126SYSCALL_DEFINE0(getpgrp)
1127{
1128 return do_getpgid(0);
1129}
1130
1131#endif
1132
1133SYSCALL_DEFINE1(getsid, pid_t, pid)
1134{
1135 struct task_struct *p;
1136 struct pid *sid;
1137 int retval;
1138
1139 rcu_read_lock();
1140 if (!pid)
1141 sid = task_session(current);
1142 else {
1143 retval = -ESRCH;
1144 p = find_task_by_vpid(pid);
1145 if (!p)
1146 goto out;
1147 sid = task_session(p);
1148 if (!sid)
1149 goto out;
1150
1151 retval = security_task_getsid(p);
1152 if (retval)
1153 goto out;
1154 }
1155 retval = pid_vnr(sid);
1156out:
1157 rcu_read_unlock();
1158 return retval;
1159}
1160
1161static void set_special_pids(struct pid *pid)
1162{
1163 struct task_struct *curr = current->group_leader;
1164
1165 if (task_session(curr) != pid)
1166 change_pid(curr, PIDTYPE_SID, pid);
1167
1168 if (task_pgrp(curr) != pid)
1169 change_pid(curr, PIDTYPE_PGID, pid);
1170}
1171
1172int ksys_setsid(void)
1173{
1174 struct task_struct *group_leader = current->group_leader;
1175 struct pid *sid = task_pid(group_leader);
1176 pid_t session = pid_vnr(sid);
1177 int err = -EPERM;
1178
1179 write_lock_irq(&tasklist_lock);
1180 /* Fail if I am already a session leader */
1181 if (group_leader->signal->leader)
1182 goto out;
1183
1184 /* Fail if a process group id already exists that equals the
1185 * proposed session id.
1186 */
1187 if (pid_task(sid, PIDTYPE_PGID))
1188 goto out;
1189
1190 group_leader->signal->leader = 1;
1191 set_special_pids(sid);
1192
1193 proc_clear_tty(group_leader);
1194
1195 err = session;
1196out:
1197 write_unlock_irq(&tasklist_lock);
1198 if (err > 0) {
1199 proc_sid_connector(group_leader);
1200 sched_autogroup_create_attach(group_leader);
1201 }
1202 return err;
1203}
1204
1205SYSCALL_DEFINE0(setsid)
1206{
1207 return ksys_setsid();
1208}
1209
1210DECLARE_RWSEM(uts_sem);
1211
1212#ifdef COMPAT_UTS_MACHINE
1213#define override_architecture(name) \
1214 (personality(current->personality) == PER_LINUX32 && \
1215 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1216 sizeof(COMPAT_UTS_MACHINE)))
1217#else
1218#define override_architecture(name) 0
1219#endif
1220
1221/*
1222 * Work around broken programs that cannot handle "Linux 3.0".
1223 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1224 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be
1225 * 2.6.60.
1226 */
1227static int override_release(char __user *release, size_t len)
1228{
1229 int ret = 0;
1230
1231 if (current->personality & UNAME26) {
1232 const char *rest = UTS_RELEASE;
1233 char buf[65] = { 0 };
1234 int ndots = 0;
1235 unsigned v;
1236 size_t copy;
1237
1238 while (*rest) {
1239 if (*rest == '.' && ++ndots >= 3)
1240 break;
1241 if (!isdigit(*rest) && *rest != '.')
1242 break;
1243 rest++;
1244 }
1245 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 60;
1246 copy = clamp_t(size_t, len, 1, sizeof(buf));
1247 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1248 ret = copy_to_user(release, buf, copy + 1);
1249 }
1250 return ret;
1251}
1252
1253SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1254{
1255 struct new_utsname tmp;
1256
1257 down_read(&uts_sem);
1258 memcpy(&tmp, utsname(), sizeof(tmp));
1259 up_read(&uts_sem);
1260 if (copy_to_user(name, &tmp, sizeof(tmp)))
1261 return -EFAULT;
1262
1263 if (override_release(name->release, sizeof(name->release)))
1264 return -EFAULT;
1265 if (override_architecture(name))
1266 return -EFAULT;
1267 return 0;
1268}
1269
1270#ifdef __ARCH_WANT_SYS_OLD_UNAME
1271/*
1272 * Old cruft
1273 */
1274SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1275{
1276 struct old_utsname tmp;
1277
1278 if (!name)
1279 return -EFAULT;
1280
1281 down_read(&uts_sem);
1282 memcpy(&tmp, utsname(), sizeof(tmp));
1283 up_read(&uts_sem);
1284 if (copy_to_user(name, &tmp, sizeof(tmp)))
1285 return -EFAULT;
1286
1287 if (override_release(name->release, sizeof(name->release)))
1288 return -EFAULT;
1289 if (override_architecture(name))
1290 return -EFAULT;
1291 return 0;
1292}
1293
1294SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1295{
1296 struct oldold_utsname tmp;
1297
1298 if (!name)
1299 return -EFAULT;
1300
1301 memset(&tmp, 0, sizeof(tmp));
1302
1303 down_read(&uts_sem);
1304 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1305 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1306 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1307 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1308 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
1309 up_read(&uts_sem);
1310 if (copy_to_user(name, &tmp, sizeof(tmp)))
1311 return -EFAULT;
1312
1313 if (override_architecture(name))
1314 return -EFAULT;
1315 if (override_release(name->release, sizeof(name->release)))
1316 return -EFAULT;
1317 return 0;
1318}
1319#endif
1320
1321SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1322{
1323 int errno;
1324 char tmp[__NEW_UTS_LEN];
1325
1326 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1327 return -EPERM;
1328
1329 if (len < 0 || len > __NEW_UTS_LEN)
1330 return -EINVAL;
1331 errno = -EFAULT;
1332 if (!copy_from_user(tmp, name, len)) {
1333 struct new_utsname *u;
1334
1335 down_write(&uts_sem);
1336 u = utsname();
1337 memcpy(u->nodename, tmp, len);
1338 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1339 errno = 0;
1340 uts_proc_notify(UTS_PROC_HOSTNAME);
1341 up_write(&uts_sem);
1342 }
1343 return errno;
1344}
1345
1346#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1347
1348SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1349{
1350 int i;
1351 struct new_utsname *u;
1352 char tmp[__NEW_UTS_LEN + 1];
1353
1354 if (len < 0)
1355 return -EINVAL;
1356 down_read(&uts_sem);
1357 u = utsname();
1358 i = 1 + strlen(u->nodename);
1359 if (i > len)
1360 i = len;
1361 memcpy(tmp, u->nodename, i);
1362 up_read(&uts_sem);
1363 if (copy_to_user(name, tmp, i))
1364 return -EFAULT;
1365 return 0;
1366}
1367
1368#endif
1369
1370/*
1371 * Only setdomainname; getdomainname can be implemented by calling
1372 * uname()
1373 */
1374SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1375{
1376 int errno;
1377 char tmp[__NEW_UTS_LEN];
1378
1379 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1380 return -EPERM;
1381 if (len < 0 || len > __NEW_UTS_LEN)
1382 return -EINVAL;
1383
1384 errno = -EFAULT;
1385 if (!copy_from_user(tmp, name, len)) {
1386 struct new_utsname *u;
1387
1388 down_write(&uts_sem);
1389 u = utsname();
1390 memcpy(u->domainname, tmp, len);
1391 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1392 errno = 0;
1393 uts_proc_notify(UTS_PROC_DOMAINNAME);
1394 up_write(&uts_sem);
1395 }
1396 return errno;
1397}
1398
1399SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1400{
1401 struct rlimit value;
1402 int ret;
1403
1404 ret = do_prlimit(current, resource, NULL, &value);
1405 if (!ret)
1406 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1407
1408 return ret;
1409}
1410
1411#ifdef CONFIG_COMPAT
1412
1413COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1414 struct compat_rlimit __user *, rlim)
1415{
1416 struct rlimit r;
1417 struct compat_rlimit r32;
1418
1419 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1420 return -EFAULT;
1421
1422 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1423 r.rlim_cur = RLIM_INFINITY;
1424 else
1425 r.rlim_cur = r32.rlim_cur;
1426 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1427 r.rlim_max = RLIM_INFINITY;
1428 else
1429 r.rlim_max = r32.rlim_max;
1430 return do_prlimit(current, resource, &r, NULL);
1431}
1432
1433COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1434 struct compat_rlimit __user *, rlim)
1435{
1436 struct rlimit r;
1437 int ret;
1438
1439 ret = do_prlimit(current, resource, NULL, &r);
1440 if (!ret) {
1441 struct compat_rlimit r32;
1442 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1443 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1444 else
1445 r32.rlim_cur = r.rlim_cur;
1446 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1447 r32.rlim_max = COMPAT_RLIM_INFINITY;
1448 else
1449 r32.rlim_max = r.rlim_max;
1450
1451 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1452 return -EFAULT;
1453 }
1454 return ret;
1455}
1456
1457#endif
1458
1459#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1460
1461/*
1462 * Back compatibility for getrlimit. Needed for some apps.
1463 */
1464SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1465 struct rlimit __user *, rlim)
1466{
1467 struct rlimit x;
1468 if (resource >= RLIM_NLIMITS)
1469 return -EINVAL;
1470
1471 resource = array_index_nospec(resource, RLIM_NLIMITS);
1472 task_lock(current->group_leader);
1473 x = current->signal->rlim[resource];
1474 task_unlock(current->group_leader);
1475 if (x.rlim_cur > 0x7FFFFFFF)
1476 x.rlim_cur = 0x7FFFFFFF;
1477 if (x.rlim_max > 0x7FFFFFFF)
1478 x.rlim_max = 0x7FFFFFFF;
1479 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1480}
1481
1482#ifdef CONFIG_COMPAT
1483COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1484 struct compat_rlimit __user *, rlim)
1485{
1486 struct rlimit r;
1487
1488 if (resource >= RLIM_NLIMITS)
1489 return -EINVAL;
1490
1491 resource = array_index_nospec(resource, RLIM_NLIMITS);
1492 task_lock(current->group_leader);
1493 r = current->signal->rlim[resource];
1494 task_unlock(current->group_leader);
1495 if (r.rlim_cur > 0x7FFFFFFF)
1496 r.rlim_cur = 0x7FFFFFFF;
1497 if (r.rlim_max > 0x7FFFFFFF)
1498 r.rlim_max = 0x7FFFFFFF;
1499
1500 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1501 put_user(r.rlim_max, &rlim->rlim_max))
1502 return -EFAULT;
1503 return 0;
1504}
1505#endif
1506
1507#endif
1508
1509static inline bool rlim64_is_infinity(__u64 rlim64)
1510{
1511#if BITS_PER_LONG < 64
1512 return rlim64 >= ULONG_MAX;
1513#else
1514 return rlim64 == RLIM64_INFINITY;
1515#endif
1516}
1517
1518static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1519{
1520 if (rlim->rlim_cur == RLIM_INFINITY)
1521 rlim64->rlim_cur = RLIM64_INFINITY;
1522 else
1523 rlim64->rlim_cur = rlim->rlim_cur;
1524 if (rlim->rlim_max == RLIM_INFINITY)
1525 rlim64->rlim_max = RLIM64_INFINITY;
1526 else
1527 rlim64->rlim_max = rlim->rlim_max;
1528}
1529
1530static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1531{
1532 if (rlim64_is_infinity(rlim64->rlim_cur))
1533 rlim->rlim_cur = RLIM_INFINITY;
1534 else
1535 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1536 if (rlim64_is_infinity(rlim64->rlim_max))
1537 rlim->rlim_max = RLIM_INFINITY;
1538 else
1539 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1540}
1541
1542/* make sure you are allowed to change @tsk limits before calling this */
1543int do_prlimit(struct task_struct *tsk, unsigned int resource,
1544 struct rlimit *new_rlim, struct rlimit *old_rlim)
1545{
1546 struct rlimit *rlim;
1547 int retval = 0;
1548
1549 if (resource >= RLIM_NLIMITS)
1550 return -EINVAL;
1551 if (new_rlim) {
1552 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1553 return -EINVAL;
1554 if (resource == RLIMIT_NOFILE &&
1555 new_rlim->rlim_max > sysctl_nr_open)
1556 return -EPERM;
1557 }
1558
1559 /* protect tsk->signal and tsk->sighand from disappearing */
1560 read_lock(&tasklist_lock);
1561 if (!tsk->sighand) {
1562 retval = -ESRCH;
1563 goto out;
1564 }
1565
1566 rlim = tsk->signal->rlim + resource;
1567 task_lock(tsk->group_leader);
1568 if (new_rlim) {
1569 /* Keep the capable check against init_user_ns until
1570 cgroups can contain all limits */
1571 if (new_rlim->rlim_max > rlim->rlim_max &&
1572 !capable(CAP_SYS_RESOURCE))
1573 retval = -EPERM;
1574 if (!retval)
1575 retval = security_task_setrlimit(tsk, resource, new_rlim);
1576 }
1577 if (!retval) {
1578 if (old_rlim)
1579 *old_rlim = *rlim;
1580 if (new_rlim)
1581 *rlim = *new_rlim;
1582 }
1583 task_unlock(tsk->group_leader);
1584
1585 /*
1586 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
1587 * infite. In case of RLIM_INFINITY the posix CPU timer code
1588 * ignores the rlimit.
1589 */
1590 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1591 new_rlim->rlim_cur != RLIM_INFINITY &&
1592 IS_ENABLED(CONFIG_POSIX_TIMERS))
1593 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1594out:
1595 read_unlock(&tasklist_lock);
1596 return retval;
1597}
1598
1599/* rcu lock must be held */
1600static int check_prlimit_permission(struct task_struct *task,
1601 unsigned int flags)
1602{
1603 const struct cred *cred = current_cred(), *tcred;
1604 bool id_match;
1605
1606 if (current == task)
1607 return 0;
1608
1609 tcred = __task_cred(task);
1610 id_match = (uid_eq(cred->uid, tcred->euid) &&
1611 uid_eq(cred->uid, tcred->suid) &&
1612 uid_eq(cred->uid, tcred->uid) &&
1613 gid_eq(cred->gid, tcred->egid) &&
1614 gid_eq(cred->gid, tcred->sgid) &&
1615 gid_eq(cred->gid, tcred->gid));
1616 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1617 return -EPERM;
1618
1619 return security_task_prlimit(cred, tcred, flags);
1620}
1621
1622SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1623 const struct rlimit64 __user *, new_rlim,
1624 struct rlimit64 __user *, old_rlim)
1625{
1626 struct rlimit64 old64, new64;
1627 struct rlimit old, new;
1628 struct task_struct *tsk;
1629 unsigned int checkflags = 0;
1630 int ret;
1631
1632 if (old_rlim)
1633 checkflags |= LSM_PRLIMIT_READ;
1634
1635 if (new_rlim) {
1636 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1637 return -EFAULT;
1638 rlim64_to_rlim(&new64, &new);
1639 checkflags |= LSM_PRLIMIT_WRITE;
1640 }
1641
1642 rcu_read_lock();
1643 tsk = pid ? find_task_by_vpid(pid) : current;
1644 if (!tsk) {
1645 rcu_read_unlock();
1646 return -ESRCH;
1647 }
1648 ret = check_prlimit_permission(tsk, checkflags);
1649 if (ret) {
1650 rcu_read_unlock();
1651 return ret;
1652 }
1653 get_task_struct(tsk);
1654 rcu_read_unlock();
1655
1656 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1657 old_rlim ? &old : NULL);
1658
1659 if (!ret && old_rlim) {
1660 rlim_to_rlim64(&old, &old64);
1661 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1662 ret = -EFAULT;
1663 }
1664
1665 put_task_struct(tsk);
1666 return ret;
1667}
1668
1669SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1670{
1671 struct rlimit new_rlim;
1672
1673 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1674 return -EFAULT;
1675 return do_prlimit(current, resource, &new_rlim, NULL);
1676}
1677
1678/*
1679 * It would make sense to put struct rusage in the task_struct,
1680 * except that would make the task_struct be *really big*. After
1681 * task_struct gets moved into malloc'ed memory, it would
1682 * make sense to do this. It will make moving the rest of the information
1683 * a lot simpler! (Which we're not doing right now because we're not
1684 * measuring them yet).
1685 *
1686 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1687 * races with threads incrementing their own counters. But since word
1688 * reads are atomic, we either get new values or old values and we don't
1689 * care which for the sums. We always take the siglock to protect reading
1690 * the c* fields from p->signal from races with exit.c updating those
1691 * fields when reaping, so a sample either gets all the additions of a
1692 * given child after it's reaped, or none so this sample is before reaping.
1693 *
1694 * Locking:
1695 * We need to take the siglock for CHILDEREN, SELF and BOTH
1696 * for the cases current multithreaded, non-current single threaded
1697 * non-current multithreaded. Thread traversal is now safe with
1698 * the siglock held.
1699 * Strictly speaking, we donot need to take the siglock if we are current and
1700 * single threaded, as no one else can take our signal_struct away, no one
1701 * else can reap the children to update signal->c* counters, and no one else
1702 * can race with the signal-> fields. If we do not take any lock, the
1703 * signal-> fields could be read out of order while another thread was just
1704 * exiting. So we should place a read memory barrier when we avoid the lock.
1705 * On the writer side, write memory barrier is implied in __exit_signal
1706 * as __exit_signal releases the siglock spinlock after updating the signal->
1707 * fields. But we don't do this yet to keep things simple.
1708 *
1709 */
1710
1711static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1712{
1713 r->ru_nvcsw += t->nvcsw;
1714 r->ru_nivcsw += t->nivcsw;
1715 r->ru_minflt += t->min_flt;
1716 r->ru_majflt += t->maj_flt;
1717 r->ru_inblock += task_io_get_inblock(t);
1718 r->ru_oublock += task_io_get_oublock(t);
1719}
1720
1721void getrusage(struct task_struct *p, int who, struct rusage *r)
1722{
1723 struct task_struct *t;
1724 unsigned long flags;
1725 u64 tgutime, tgstime, utime, stime;
1726 unsigned long maxrss = 0;
1727
1728 memset((char *)r, 0, sizeof (*r));
1729 utime = stime = 0;
1730
1731 if (who == RUSAGE_THREAD) {
1732 task_cputime_adjusted(current, &utime, &stime);
1733 accumulate_thread_rusage(p, r);
1734 maxrss = p->signal->maxrss;
1735 goto out;
1736 }
1737
1738 if (!lock_task_sighand(p, &flags))
1739 return;
1740
1741 switch (who) {
1742 case RUSAGE_BOTH:
1743 case RUSAGE_CHILDREN:
1744 utime = p->signal->cutime;
1745 stime = p->signal->cstime;
1746 r->ru_nvcsw = p->signal->cnvcsw;
1747 r->ru_nivcsw = p->signal->cnivcsw;
1748 r->ru_minflt = p->signal->cmin_flt;
1749 r->ru_majflt = p->signal->cmaj_flt;
1750 r->ru_inblock = p->signal->cinblock;
1751 r->ru_oublock = p->signal->coublock;
1752 maxrss = p->signal->cmaxrss;
1753
1754 if (who == RUSAGE_CHILDREN)
1755 break;
1756 fallthrough;
1757
1758 case RUSAGE_SELF:
1759 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1760 utime += tgutime;
1761 stime += tgstime;
1762 r->ru_nvcsw += p->signal->nvcsw;
1763 r->ru_nivcsw += p->signal->nivcsw;
1764 r->ru_minflt += p->signal->min_flt;
1765 r->ru_majflt += p->signal->maj_flt;
1766 r->ru_inblock += p->signal->inblock;
1767 r->ru_oublock += p->signal->oublock;
1768 if (maxrss < p->signal->maxrss)
1769 maxrss = p->signal->maxrss;
1770 t = p;
1771 do {
1772 accumulate_thread_rusage(t, r);
1773 } while_each_thread(p, t);
1774 break;
1775
1776 default:
1777 BUG();
1778 }
1779 unlock_task_sighand(p, &flags);
1780
1781out:
1782 r->ru_utime = ns_to_kernel_old_timeval(utime);
1783 r->ru_stime = ns_to_kernel_old_timeval(stime);
1784
1785 if (who != RUSAGE_CHILDREN) {
1786 struct mm_struct *mm = get_task_mm(p);
1787
1788 if (mm) {
1789 setmax_mm_hiwater_rss(&maxrss, mm);
1790 mmput(mm);
1791 }
1792 }
1793 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1794}
1795
1796SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1797{
1798 struct rusage r;
1799
1800 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1801 who != RUSAGE_THREAD)
1802 return -EINVAL;
1803
1804 getrusage(current, who, &r);
1805 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1806}
1807
1808#ifdef CONFIG_COMPAT
1809COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1810{
1811 struct rusage r;
1812
1813 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1814 who != RUSAGE_THREAD)
1815 return -EINVAL;
1816
1817 getrusage(current, who, &r);
1818 return put_compat_rusage(&r, ru);
1819}
1820#endif
1821
1822SYSCALL_DEFINE1(umask, int, mask)
1823{
1824 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1825 return mask;
1826}
1827
1828static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1829{
1830 struct fd exe;
1831 struct file *old_exe, *exe_file;
1832 struct inode *inode;
1833 int err;
1834
1835 exe = fdget(fd);
1836 if (!exe.file)
1837 return -EBADF;
1838
1839 inode = file_inode(exe.file);
1840
1841 /*
1842 * Because the original mm->exe_file points to executable file, make
1843 * sure that this one is executable as well, to avoid breaking an
1844 * overall picture.
1845 */
1846 err = -EACCES;
1847 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
1848 goto exit;
1849
1850 err = inode_permission(inode, MAY_EXEC);
1851 if (err)
1852 goto exit;
1853
1854 /*
1855 * Forbid mm->exe_file change if old file still mapped.
1856 */
1857 exe_file = get_mm_exe_file(mm);
1858 err = -EBUSY;
1859 if (exe_file) {
1860 struct vm_area_struct *vma;
1861
1862 mmap_read_lock(mm);
1863 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1864 if (!vma->vm_file)
1865 continue;
1866 if (path_equal(&vma->vm_file->f_path,
1867 &exe_file->f_path))
1868 goto exit_err;
1869 }
1870
1871 mmap_read_unlock(mm);
1872 fput(exe_file);
1873 }
1874
1875 err = 0;
1876 /* set the new file, lockless */
1877 get_file(exe.file);
1878 old_exe = xchg(&mm->exe_file, exe.file);
1879 if (old_exe)
1880 fput(old_exe);
1881exit:
1882 fdput(exe);
1883 return err;
1884exit_err:
1885 mmap_read_unlock(mm);
1886 fput(exe_file);
1887 goto exit;
1888}
1889
1890/*
1891 * Check arithmetic relations of passed addresses.
1892 *
1893 * WARNING: we don't require any capability here so be very careful
1894 * in what is allowed for modification from userspace.
1895 */
1896static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
1897{
1898 unsigned long mmap_max_addr = TASK_SIZE;
1899 int error = -EINVAL, i;
1900
1901 static const unsigned char offsets[] = {
1902 offsetof(struct prctl_mm_map, start_code),
1903 offsetof(struct prctl_mm_map, end_code),
1904 offsetof(struct prctl_mm_map, start_data),
1905 offsetof(struct prctl_mm_map, end_data),
1906 offsetof(struct prctl_mm_map, start_brk),
1907 offsetof(struct prctl_mm_map, brk),
1908 offsetof(struct prctl_mm_map, start_stack),
1909 offsetof(struct prctl_mm_map, arg_start),
1910 offsetof(struct prctl_mm_map, arg_end),
1911 offsetof(struct prctl_mm_map, env_start),
1912 offsetof(struct prctl_mm_map, env_end),
1913 };
1914
1915 /*
1916 * Make sure the members are not somewhere outside
1917 * of allowed address space.
1918 */
1919 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1920 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1921
1922 if ((unsigned long)val >= mmap_max_addr ||
1923 (unsigned long)val < mmap_min_addr)
1924 goto out;
1925 }
1926
1927 /*
1928 * Make sure the pairs are ordered.
1929 */
1930#define __prctl_check_order(__m1, __op, __m2) \
1931 ((unsigned long)prctl_map->__m1 __op \
1932 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1933 error = __prctl_check_order(start_code, <, end_code);
1934 error |= __prctl_check_order(start_data,<=, end_data);
1935 error |= __prctl_check_order(start_brk, <=, brk);
1936 error |= __prctl_check_order(arg_start, <=, arg_end);
1937 error |= __prctl_check_order(env_start, <=, env_end);
1938 if (error)
1939 goto out;
1940#undef __prctl_check_order
1941
1942 error = -EINVAL;
1943
1944 /*
1945 * @brk should be after @end_data in traditional maps.
1946 */
1947 if (prctl_map->start_brk <= prctl_map->end_data ||
1948 prctl_map->brk <= prctl_map->end_data)
1949 goto out;
1950
1951 /*
1952 * Neither we should allow to override limits if they set.
1953 */
1954 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1955 prctl_map->start_brk, prctl_map->end_data,
1956 prctl_map->start_data))
1957 goto out;
1958
1959 error = 0;
1960out:
1961 return error;
1962}
1963
1964#ifdef CONFIG_CHECKPOINT_RESTORE
1965static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1966{
1967 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1968 unsigned long user_auxv[AT_VECTOR_SIZE];
1969 struct mm_struct *mm = current->mm;
1970 int error;
1971
1972 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1973 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1974
1975 if (opt == PR_SET_MM_MAP_SIZE)
1976 return put_user((unsigned int)sizeof(prctl_map),
1977 (unsigned int __user *)addr);
1978
1979 if (data_size != sizeof(prctl_map))
1980 return -EINVAL;
1981
1982 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1983 return -EFAULT;
1984
1985 error = validate_prctl_map_addr(&prctl_map);
1986 if (error)
1987 return error;
1988
1989 if (prctl_map.auxv_size) {
1990 /*
1991 * Someone is trying to cheat the auxv vector.
1992 */
1993 if (!prctl_map.auxv ||
1994 prctl_map.auxv_size > sizeof(mm->saved_auxv))
1995 return -EINVAL;
1996
1997 memset(user_auxv, 0, sizeof(user_auxv));
1998 if (copy_from_user(user_auxv,
1999 (const void __user *)prctl_map.auxv,
2000 prctl_map.auxv_size))
2001 return -EFAULT;
2002
2003 /* Last entry must be AT_NULL as specification requires */
2004 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
2005 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
2006 }
2007
2008 if (prctl_map.exe_fd != (u32)-1) {
2009 /*
2010 * Check if the current user is checkpoint/restore capable.
2011 * At the time of this writing, it checks for CAP_SYS_ADMIN
2012 * or CAP_CHECKPOINT_RESTORE.
2013 * Note that a user with access to ptrace can masquerade an
2014 * arbitrary program as any executable, even setuid ones.
2015 * This may have implications in the tomoyo subsystem.
2016 */
2017 if (!checkpoint_restore_ns_capable(current_user_ns()))
2018 return -EPERM;
2019
2020 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
2021 if (error)
2022 return error;
2023 }
2024
2025 /*
2026 * arg_lock protects concurent updates but we still need mmap_lock for
2027 * read to exclude races with sys_brk.
2028 */
2029 mmap_read_lock(mm);
2030
2031 /*
2032 * We don't validate if these members are pointing to
2033 * real present VMAs because application may have correspond
2034 * VMAs already unmapped and kernel uses these members for statistics
2035 * output in procfs mostly, except
2036 *
2037 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups
2038 * for VMAs when updating these memvers so anything wrong written
2039 * here cause kernel to swear at userspace program but won't lead
2040 * to any problem in kernel itself
2041 */
2042
2043 spin_lock(&mm->arg_lock);
2044 mm->start_code = prctl_map.start_code;
2045 mm->end_code = prctl_map.end_code;
2046 mm->start_data = prctl_map.start_data;
2047 mm->end_data = prctl_map.end_data;
2048 mm->start_brk = prctl_map.start_brk;
2049 mm->brk = prctl_map.brk;
2050 mm->start_stack = prctl_map.start_stack;
2051 mm->arg_start = prctl_map.arg_start;
2052 mm->arg_end = prctl_map.arg_end;
2053 mm->env_start = prctl_map.env_start;
2054 mm->env_end = prctl_map.env_end;
2055 spin_unlock(&mm->arg_lock);
2056
2057 /*
2058 * Note this update of @saved_auxv is lockless thus
2059 * if someone reads this member in procfs while we're
2060 * updating -- it may get partly updated results. It's
2061 * known and acceptable trade off: we leave it as is to
2062 * not introduce additional locks here making the kernel
2063 * more complex.
2064 */
2065 if (prctl_map.auxv_size)
2066 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2067
2068 mmap_read_unlock(mm);
2069 return 0;
2070}
2071#endif /* CONFIG_CHECKPOINT_RESTORE */
2072
2073static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2074 unsigned long len)
2075{
2076 /*
2077 * This doesn't move the auxiliary vector itself since it's pinned to
2078 * mm_struct, but it permits filling the vector with new values. It's
2079 * up to the caller to provide sane values here, otherwise userspace
2080 * tools which use this vector might be unhappy.
2081 */
2082 unsigned long user_auxv[AT_VECTOR_SIZE];
2083
2084 if (len > sizeof(user_auxv))
2085 return -EINVAL;
2086
2087 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2088 return -EFAULT;
2089
2090 /* Make sure the last entry is always AT_NULL */
2091 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2092 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2093
2094 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2095
2096 task_lock(current);
2097 memcpy(mm->saved_auxv, user_auxv, len);
2098 task_unlock(current);
2099
2100 return 0;
2101}
2102
2103static int prctl_set_mm(int opt, unsigned long addr,
2104 unsigned long arg4, unsigned long arg5)
2105{
2106 struct mm_struct *mm = current->mm;
2107 struct prctl_mm_map prctl_map = {
2108 .auxv = NULL,
2109 .auxv_size = 0,
2110 .exe_fd = -1,
2111 };
2112 struct vm_area_struct *vma;
2113 int error;
2114
2115 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2116 opt != PR_SET_MM_MAP &&
2117 opt != PR_SET_MM_MAP_SIZE)))
2118 return -EINVAL;
2119
2120#ifdef CONFIG_CHECKPOINT_RESTORE
2121 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2122 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2123#endif
2124
2125 if (!capable(CAP_SYS_RESOURCE))
2126 return -EPERM;
2127
2128 if (opt == PR_SET_MM_EXE_FILE)
2129 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
2130
2131 if (opt == PR_SET_MM_AUXV)
2132 return prctl_set_auxv(mm, addr, arg4);
2133
2134 if (addr >= TASK_SIZE || addr < mmap_min_addr)
2135 return -EINVAL;
2136
2137 error = -EINVAL;
2138
2139 /*
2140 * arg_lock protects concurent updates of arg boundaries, we need
2141 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
2142 * validation.
2143 */
2144 mmap_read_lock(mm);
2145 vma = find_vma(mm, addr);
2146
2147 spin_lock(&mm->arg_lock);
2148 prctl_map.start_code = mm->start_code;
2149 prctl_map.end_code = mm->end_code;
2150 prctl_map.start_data = mm->start_data;
2151 prctl_map.end_data = mm->end_data;
2152 prctl_map.start_brk = mm->start_brk;
2153 prctl_map.brk = mm->brk;
2154 prctl_map.start_stack = mm->start_stack;
2155 prctl_map.arg_start = mm->arg_start;
2156 prctl_map.arg_end = mm->arg_end;
2157 prctl_map.env_start = mm->env_start;
2158 prctl_map.env_end = mm->env_end;
2159
2160 switch (opt) {
2161 case PR_SET_MM_START_CODE:
2162 prctl_map.start_code = addr;
2163 break;
2164 case PR_SET_MM_END_CODE:
2165 prctl_map.end_code = addr;
2166 break;
2167 case PR_SET_MM_START_DATA:
2168 prctl_map.start_data = addr;
2169 break;
2170 case PR_SET_MM_END_DATA:
2171 prctl_map.end_data = addr;
2172 break;
2173 case PR_SET_MM_START_STACK:
2174 prctl_map.start_stack = addr;
2175 break;
2176 case PR_SET_MM_START_BRK:
2177 prctl_map.start_brk = addr;
2178 break;
2179 case PR_SET_MM_BRK:
2180 prctl_map.brk = addr;
2181 break;
2182 case PR_SET_MM_ARG_START:
2183 prctl_map.arg_start = addr;
2184 break;
2185 case PR_SET_MM_ARG_END:
2186 prctl_map.arg_end = addr;
2187 break;
2188 case PR_SET_MM_ENV_START:
2189 prctl_map.env_start = addr;
2190 break;
2191 case PR_SET_MM_ENV_END:
2192 prctl_map.env_end = addr;
2193 break;
2194 default:
2195 goto out;
2196 }
2197
2198 error = validate_prctl_map_addr(&prctl_map);
2199 if (error)
2200 goto out;
2201
2202 switch (opt) {
2203 /*
2204 * If command line arguments and environment
2205 * are placed somewhere else on stack, we can
2206 * set them up here, ARG_START/END to setup
2207 * command line argumets and ENV_START/END
2208 * for environment.
2209 */
2210 case PR_SET_MM_START_STACK:
2211 case PR_SET_MM_ARG_START:
2212 case PR_SET_MM_ARG_END:
2213 case PR_SET_MM_ENV_START:
2214 case PR_SET_MM_ENV_END:
2215 if (!vma) {
2216 error = -EFAULT;
2217 goto out;
2218 }
2219 }
2220
2221 mm->start_code = prctl_map.start_code;
2222 mm->end_code = prctl_map.end_code;
2223 mm->start_data = prctl_map.start_data;
2224 mm->end_data = prctl_map.end_data;
2225 mm->start_brk = prctl_map.start_brk;
2226 mm->brk = prctl_map.brk;
2227 mm->start_stack = prctl_map.start_stack;
2228 mm->arg_start = prctl_map.arg_start;
2229 mm->arg_end = prctl_map.arg_end;
2230 mm->env_start = prctl_map.env_start;
2231 mm->env_end = prctl_map.env_end;
2232
2233 error = 0;
2234out:
2235 spin_unlock(&mm->arg_lock);
2236 mmap_read_unlock(mm);
2237 return error;
2238}
2239
2240#ifdef CONFIG_CHECKPOINT_RESTORE
2241static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2242{
2243 return put_user(me->clear_child_tid, tid_addr);
2244}
2245#else
2246static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2247{
2248 return -EINVAL;
2249}
2250#endif
2251
2252static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2253{
2254 /*
2255 * If task has has_child_subreaper - all its decendants
2256 * already have these flag too and new decendants will
2257 * inherit it on fork, skip them.
2258 *
2259 * If we've found child_reaper - skip descendants in
2260 * it's subtree as they will never get out pidns.
2261 */
2262 if (p->signal->has_child_subreaper ||
2263 is_child_reaper(task_pid(p)))
2264 return 0;
2265
2266 p->signal->has_child_subreaper = 1;
2267 return 1;
2268}
2269
2270int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
2271{
2272 return -EINVAL;
2273}
2274
2275int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2276 unsigned long ctrl)
2277{
2278 return -EINVAL;
2279}
2280
2281#define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
2282
2283SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2284 unsigned long, arg4, unsigned long, arg5)
2285{
2286 struct task_struct *me = current;
2287 unsigned char comm[sizeof(me->comm)];
2288 long error;
2289
2290 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2291 if (error != -ENOSYS)
2292 return error;
2293
2294 error = 0;
2295 switch (option) {
2296 case PR_SET_PDEATHSIG:
2297 if (!valid_signal(arg2)) {
2298 error = -EINVAL;
2299 break;
2300 }
2301 me->pdeath_signal = arg2;
2302 break;
2303 case PR_GET_PDEATHSIG:
2304 error = put_user(me->pdeath_signal, (int __user *)arg2);
2305 break;
2306 case PR_GET_DUMPABLE:
2307 error = get_dumpable(me->mm);
2308 break;
2309 case PR_SET_DUMPABLE:
2310 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2311 error = -EINVAL;
2312 break;
2313 }
2314 set_dumpable(me->mm, arg2);
2315 break;
2316
2317 case PR_SET_UNALIGN:
2318 error = SET_UNALIGN_CTL(me, arg2);
2319 break;
2320 case PR_GET_UNALIGN:
2321 error = GET_UNALIGN_CTL(me, arg2);
2322 break;
2323 case PR_SET_FPEMU:
2324 error = SET_FPEMU_CTL(me, arg2);
2325 break;
2326 case PR_GET_FPEMU:
2327 error = GET_FPEMU_CTL(me, arg2);
2328 break;
2329 case PR_SET_FPEXC:
2330 error = SET_FPEXC_CTL(me, arg2);
2331 break;
2332 case PR_GET_FPEXC:
2333 error = GET_FPEXC_CTL(me, arg2);
2334 break;
2335 case PR_GET_TIMING:
2336 error = PR_TIMING_STATISTICAL;
2337 break;
2338 case PR_SET_TIMING:
2339 if (arg2 != PR_TIMING_STATISTICAL)
2340 error = -EINVAL;
2341 break;
2342 case PR_SET_NAME:
2343 comm[sizeof(me->comm) - 1] = 0;
2344 if (strncpy_from_user(comm, (char __user *)arg2,
2345 sizeof(me->comm) - 1) < 0)
2346 return -EFAULT;
2347 set_task_comm(me, comm);
2348 proc_comm_connector(me);
2349 break;
2350 case PR_GET_NAME:
2351 get_task_comm(comm, me);
2352 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2353 return -EFAULT;
2354 break;
2355 case PR_GET_ENDIAN:
2356 error = GET_ENDIAN(me, arg2);
2357 break;
2358 case PR_SET_ENDIAN:
2359 error = SET_ENDIAN(me, arg2);
2360 break;
2361 case PR_GET_SECCOMP:
2362 error = prctl_get_seccomp();
2363 break;
2364 case PR_SET_SECCOMP:
2365 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2366 break;
2367 case PR_GET_TSC:
2368 error = GET_TSC_CTL(arg2);
2369 break;
2370 case PR_SET_TSC:
2371 error = SET_TSC_CTL(arg2);
2372 break;
2373 case PR_TASK_PERF_EVENTS_DISABLE:
2374 error = perf_event_task_disable();
2375 break;
2376 case PR_TASK_PERF_EVENTS_ENABLE:
2377 error = perf_event_task_enable();
2378 break;
2379 case PR_GET_TIMERSLACK:
2380 if (current->timer_slack_ns > ULONG_MAX)
2381 error = ULONG_MAX;
2382 else
2383 error = current->timer_slack_ns;
2384 break;
2385 case PR_SET_TIMERSLACK:
2386 if (arg2 <= 0)
2387 current->timer_slack_ns =
2388 current->default_timer_slack_ns;
2389 else
2390 current->timer_slack_ns = arg2;
2391 break;
2392 case PR_MCE_KILL:
2393 if (arg4 | arg5)
2394 return -EINVAL;
2395 switch (arg2) {
2396 case PR_MCE_KILL_CLEAR:
2397 if (arg3 != 0)
2398 return -EINVAL;
2399 current->flags &= ~PF_MCE_PROCESS;
2400 break;
2401 case PR_MCE_KILL_SET:
2402 current->flags |= PF_MCE_PROCESS;
2403 if (arg3 == PR_MCE_KILL_EARLY)
2404 current->flags |= PF_MCE_EARLY;
2405 else if (arg3 == PR_MCE_KILL_LATE)
2406 current->flags &= ~PF_MCE_EARLY;
2407 else if (arg3 == PR_MCE_KILL_DEFAULT)
2408 current->flags &=
2409 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2410 else
2411 return -EINVAL;
2412 break;
2413 default:
2414 return -EINVAL;
2415 }
2416 break;
2417 case PR_MCE_KILL_GET:
2418 if (arg2 | arg3 | arg4 | arg5)
2419 return -EINVAL;
2420 if (current->flags & PF_MCE_PROCESS)
2421 error = (current->flags & PF_MCE_EARLY) ?
2422 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2423 else
2424 error = PR_MCE_KILL_DEFAULT;
2425 break;
2426 case PR_SET_MM:
2427 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2428 break;
2429 case PR_GET_TID_ADDRESS:
2430 error = prctl_get_tid_address(me, (int __user * __user *)arg2);
2431 break;
2432 case PR_SET_CHILD_SUBREAPER:
2433 me->signal->is_child_subreaper = !!arg2;
2434 if (!arg2)
2435 break;
2436
2437 walk_process_tree(me, propagate_has_child_subreaper, NULL);
2438 break;
2439 case PR_GET_CHILD_SUBREAPER:
2440 error = put_user(me->signal->is_child_subreaper,
2441 (int __user *)arg2);
2442 break;
2443 case PR_SET_NO_NEW_PRIVS:
2444 if (arg2 != 1 || arg3 || arg4 || arg5)
2445 return -EINVAL;
2446
2447 task_set_no_new_privs(current);
2448 break;
2449 case PR_GET_NO_NEW_PRIVS:
2450 if (arg2 || arg3 || arg4 || arg5)
2451 return -EINVAL;
2452 return task_no_new_privs(current) ? 1 : 0;
2453 case PR_GET_THP_DISABLE:
2454 if (arg2 || arg3 || arg4 || arg5)
2455 return -EINVAL;
2456 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
2457 break;
2458 case PR_SET_THP_DISABLE:
2459 if (arg3 || arg4 || arg5)
2460 return -EINVAL;
2461 if (mmap_write_lock_killable(me->mm))
2462 return -EINTR;
2463 if (arg2)
2464 set_bit(MMF_DISABLE_THP, &me->mm->flags);
2465 else
2466 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
2467 mmap_write_unlock(me->mm);
2468 break;
2469 case PR_MPX_ENABLE_MANAGEMENT:
2470 case PR_MPX_DISABLE_MANAGEMENT:
2471 /* No longer implemented: */
2472 return -EINVAL;
2473 case PR_SET_FP_MODE:
2474 error = SET_FP_MODE(me, arg2);
2475 break;
2476 case PR_GET_FP_MODE:
2477 error = GET_FP_MODE(me);
2478 break;
2479 case PR_SVE_SET_VL:
2480 error = SVE_SET_VL(arg2);
2481 break;
2482 case PR_SVE_GET_VL:
2483 error = SVE_GET_VL();
2484 break;
2485 case PR_GET_SPECULATION_CTRL:
2486 if (arg3 || arg4 || arg5)
2487 return -EINVAL;
2488 error = arch_prctl_spec_ctrl_get(me, arg2);
2489 break;
2490 case PR_SET_SPECULATION_CTRL:
2491 if (arg4 || arg5)
2492 return -EINVAL;
2493 error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
2494 break;
2495 case PR_PAC_RESET_KEYS:
2496 if (arg3 || arg4 || arg5)
2497 return -EINVAL;
2498 error = PAC_RESET_KEYS(me, arg2);
2499 break;
2500 case PR_SET_TAGGED_ADDR_CTRL:
2501 if (arg3 || arg4 || arg5)
2502 return -EINVAL;
2503 error = SET_TAGGED_ADDR_CTRL(arg2);
2504 break;
2505 case PR_GET_TAGGED_ADDR_CTRL:
2506 if (arg2 || arg3 || arg4 || arg5)
2507 return -EINVAL;
2508 error = GET_TAGGED_ADDR_CTRL();
2509 break;
2510 case PR_SET_IO_FLUSHER:
2511 if (!capable(CAP_SYS_RESOURCE))
2512 return -EPERM;
2513
2514 if (arg3 || arg4 || arg5)
2515 return -EINVAL;
2516
2517 if (arg2 == 1)
2518 current->flags |= PR_IO_FLUSHER;
2519 else if (!arg2)
2520 current->flags &= ~PR_IO_FLUSHER;
2521 else
2522 return -EINVAL;
2523 break;
2524 case PR_GET_IO_FLUSHER:
2525 if (!capable(CAP_SYS_RESOURCE))
2526 return -EPERM;
2527
2528 if (arg2 || arg3 || arg4 || arg5)
2529 return -EINVAL;
2530
2531 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
2532 break;
2533 default:
2534 error = -EINVAL;
2535 break;
2536 }
2537 return error;
2538}
2539
2540SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2541 struct getcpu_cache __user *, unused)
2542{
2543 int err = 0;
2544 int cpu = raw_smp_processor_id();
2545
2546 if (cpup)
2547 err |= put_user(cpu, cpup);
2548 if (nodep)
2549 err |= put_user(cpu_to_node(cpu), nodep);
2550 return err ? -EFAULT : 0;
2551}
2552
2553/**
2554 * do_sysinfo - fill in sysinfo struct
2555 * @info: pointer to buffer to fill
2556 */
2557static int do_sysinfo(struct sysinfo *info)
2558{
2559 unsigned long mem_total, sav_total;
2560 unsigned int mem_unit, bitcount;
2561 struct timespec64 tp;
2562
2563 memset(info, 0, sizeof(struct sysinfo));
2564
2565 ktime_get_boottime_ts64(&tp);
2566 timens_add_boottime(&tp);
2567 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2568
2569 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2570
2571 info->procs = nr_threads;
2572
2573 si_meminfo(info);
2574 si_swapinfo(info);
2575
2576 /*
2577 * If the sum of all the available memory (i.e. ram + swap)
2578 * is less than can be stored in a 32 bit unsigned long then
2579 * we can be binary compatible with 2.2.x kernels. If not,
2580 * well, in that case 2.2.x was broken anyways...
2581 *
2582 * -Erik Andersen <[email protected]>
2583 */
2584
2585 mem_total = info->totalram + info->totalswap;
2586 if (mem_total < info->totalram || mem_total < info->totalswap)
2587 goto out;
2588 bitcount = 0;
2589 mem_unit = info->mem_unit;
2590 while (mem_unit > 1) {
2591 bitcount++;
2592 mem_unit >>= 1;
2593 sav_total = mem_total;
2594 mem_total <<= 1;
2595 if (mem_total < sav_total)
2596 goto out;
2597 }
2598
2599 /*
2600 * If mem_total did not overflow, multiply all memory values by
2601 * info->mem_unit and set it to 1. This leaves things compatible
2602 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2603 * kernels...
2604 */
2605
2606 info->mem_unit = 1;
2607 info->totalram <<= bitcount;
2608 info->freeram <<= bitcount;
2609 info->sharedram <<= bitcount;
2610 info->bufferram <<= bitcount;
2611 info->totalswap <<= bitcount;
2612 info->freeswap <<= bitcount;
2613 info->totalhigh <<= bitcount;
2614 info->freehigh <<= bitcount;
2615
2616out:
2617 return 0;
2618}
2619
2620SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2621{
2622 struct sysinfo val;
2623
2624 do_sysinfo(&val);
2625
2626 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2627 return -EFAULT;
2628
2629 return 0;
2630}
2631
2632#ifdef CONFIG_COMPAT
2633struct compat_sysinfo {
2634 s32 uptime;
2635 u32 loads[3];
2636 u32 totalram;
2637 u32 freeram;
2638 u32 sharedram;
2639 u32 bufferram;
2640 u32 totalswap;
2641 u32 freeswap;
2642 u16 procs;
2643 u16 pad;
2644 u32 totalhigh;
2645 u32 freehigh;
2646 u32 mem_unit;
2647 char _f[20-2*sizeof(u32)-sizeof(int)];
2648};
2649
2650COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2651{
2652 struct sysinfo s;
2653 struct compat_sysinfo s_32;
2654
2655 do_sysinfo(&s);
2656
2657 /* Check to see if any memory value is too large for 32-bit and scale
2658 * down if needed
2659 */
2660 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2661 int bitcount = 0;
2662
2663 while (s.mem_unit < PAGE_SIZE) {
2664 s.mem_unit <<= 1;
2665 bitcount++;
2666 }
2667
2668 s.totalram >>= bitcount;
2669 s.freeram >>= bitcount;
2670 s.sharedram >>= bitcount;
2671 s.bufferram >>= bitcount;
2672 s.totalswap >>= bitcount;
2673 s.freeswap >>= bitcount;
2674 s.totalhigh >>= bitcount;
2675 s.freehigh >>= bitcount;
2676 }
2677
2678 memset(&s_32, 0, sizeof(s_32));
2679 s_32.uptime = s.uptime;
2680 s_32.loads[0] = s.loads[0];
2681 s_32.loads[1] = s.loads[1];
2682 s_32.loads[2] = s.loads[2];
2683 s_32.totalram = s.totalram;
2684 s_32.freeram = s.freeram;
2685 s_32.sharedram = s.sharedram;
2686 s_32.bufferram = s.bufferram;
2687 s_32.totalswap = s.totalswap;
2688 s_32.freeswap = s.freeswap;
2689 s_32.procs = s.procs;
2690 s_32.totalhigh = s.totalhigh;
2691 s_32.freehigh = s.freehigh;
2692 s_32.mem_unit = s.mem_unit;
2693 if (copy_to_user(info, &s_32, sizeof(s_32)))
2694 return -EFAULT;
2695 return 0;
2696}
2697#endif /* CONFIG_COMPAT */