projects/linux·blob v5.15-rc3 · refs

2697 lines · 63.1 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 read_lock(&tasklist_lock);
224 switch (which) {
225 case PRIO_PROCESS:
226 if (who)
227 p = find_task_by_vpid(who);
228 else
229 p = current;
230 if (p)
231 error = set_one_prio(p, niceval, error);
232 break;
233 case PRIO_PGRP:
234 if (who)
235 pgrp = find_vpid(who);
236 else
237 pgrp = task_pgrp(current);
238 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 break;
242 case PRIO_USER:
243 uid = make_kuid(cred->user_ns, who);
244 user = cred->user;
245 if (!who)
246 uid = cred->uid;
247 else if (!uid_eq(uid, cred->uid)) {
248 user = find_user(uid);
249 if (!user)
250 goto out_unlock; /* No processes for this user */
251 }
252 do_each_thread(g, p) {
253 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
254 error = set_one_prio(p, niceval, error);
255 } while_each_thread(g, p);
256 if (!uid_eq(uid, cred->uid))
257 free_uid(user); /* For find_user() */
258 break;
259 }
260out_unlock:
261 read_unlock(&tasklist_lock);
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 read_lock(&tasklist_lock);
287 switch (which) {
288 case PRIO_PROCESS:
289 if (who)
290 p = find_task_by_vpid(who);
291 else
292 p = current;
293 if (p) {
294 niceval = nice_to_rlimit(task_nice(p));
295 if (niceval > retval)
296 retval = niceval;
297 }
298 break;
299 case PRIO_PGRP:
300 if (who)
301 pgrp = find_vpid(who);
302 else
303 pgrp = task_pgrp(current);
304 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 break;
310 case PRIO_USER:
311 uid = make_kuid(cred->user_ns, who);
312 user = cred->user;
313 if (!who)
314 uid = cred->uid;
315 else if (!uid_eq(uid, cred->uid)) {
316 user = find_user(uid);
317 if (!user)
318 goto out_unlock; /* No processes for this user */
319 }
320 do_each_thread(g, p) {
321 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
322 niceval = nice_to_rlimit(task_nice(p));
323 if (niceval > retval)
324 retval = niceval;
325 }
326 } while_each_thread(g, p);
327 if (!uid_eq(uid, cred->uid))
328 free_uid(user); /* for find_user() */
329 break;
330 }
331out_unlock:
332 read_unlock(&tasklist_lock);
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 /*
476 * We don't fail in case of NPROC limit excess here because too many
477 * poorly written programs don't check set*uid() return code, assuming
478 * it never fails if called by root. We may still enforce NPROC limit
479 * for programs doing set*uid()+execve() by harmlessly deferring the
480 * failure to the execve() stage.
481 */
482 if (is_ucounts_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) &&
483 new_user != INIT_USER &&
484 !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN))
485 current->flags |= PF_NPROC_EXCEEDED;
486 else
487 current->flags &= ~PF_NPROC_EXCEEDED;
488
489 free_uid(new->user);
490 new->user = new_user;
491 return 0;
492}
493
494/*
495 * Unprivileged users may change the real uid to the effective uid
496 * or vice versa. (BSD-style)
497 *
498 * If you set the real uid at all, or set the effective uid to a value not
499 * equal to the real uid, then the saved uid is set to the new effective uid.
500 *
501 * This makes it possible for a setuid program to completely drop its
502 * privileges, which is often a useful assertion to make when you are doing
503 * a security audit over a program.
504 *
505 * The general idea is that a program which uses just setreuid() will be
506 * 100% compatible with BSD. A program which uses just setuid() will be
507 * 100% compatible with POSIX with saved IDs.
508 */
509long __sys_setreuid(uid_t ruid, uid_t euid)
510{
511 struct user_namespace *ns = current_user_ns();
512 const struct cred *old;
513 struct cred *new;
514 int retval;
515 kuid_t kruid, keuid;
516
517 kruid = make_kuid(ns, ruid);
518 keuid = make_kuid(ns, euid);
519
520 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
521 return -EINVAL;
522 if ((euid != (uid_t) -1) && !uid_valid(keuid))
523 return -EINVAL;
524
525 new = prepare_creds();
526 if (!new)
527 return -ENOMEM;
528 old = current_cred();
529
530 retval = -EPERM;
531 if (ruid != (uid_t) -1) {
532 new->uid = kruid;
533 if (!uid_eq(old->uid, kruid) &&
534 !uid_eq(old->euid, kruid) &&
535 !ns_capable_setid(old->user_ns, CAP_SETUID))
536 goto error;
537 }
538
539 if (euid != (uid_t) -1) {
540 new->euid = keuid;
541 if (!uid_eq(old->uid, keuid) &&
542 !uid_eq(old->euid, keuid) &&
543 !uid_eq(old->suid, keuid) &&
544 !ns_capable_setid(old->user_ns, CAP_SETUID))
545 goto error;
546 }
547
548 if (!uid_eq(new->uid, old->uid)) {
549 retval = set_user(new);
550 if (retval < 0)
551 goto error;
552 }
553 if (ruid != (uid_t) -1 ||
554 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
555 new->suid = new->euid;
556 new->fsuid = new->euid;
557
558 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
559 if (retval < 0)
560 goto error;
561
562 retval = set_cred_ucounts(new);
563 if (retval < 0)
564 goto error;
565
566 return commit_creds(new);
567
568error:
569 abort_creds(new);
570 return retval;
571}
572
573SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
574{
575 return __sys_setreuid(ruid, euid);
576}
577
578/*
579 * setuid() is implemented like SysV with SAVED_IDS
580 *
581 * Note that SAVED_ID's is deficient in that a setuid root program
582 * like sendmail, for example, cannot set its uid to be a normal
583 * user and then switch back, because if you're root, setuid() sets
584 * the saved uid too. If you don't like this, blame the bright people
585 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
586 * will allow a root program to temporarily drop privileges and be able to
587 * regain them by swapping the real and effective uid.
588 */
589long __sys_setuid(uid_t uid)
590{
591 struct user_namespace *ns = current_user_ns();
592 const struct cred *old;
593 struct cred *new;
594 int retval;
595 kuid_t kuid;
596
597 kuid = make_kuid(ns, uid);
598 if (!uid_valid(kuid))
599 return -EINVAL;
600
601 new = prepare_creds();
602 if (!new)
603 return -ENOMEM;
604 old = current_cred();
605
606 retval = -EPERM;
607 if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
608 new->suid = new->uid = kuid;
609 if (!uid_eq(kuid, old->uid)) {
610 retval = set_user(new);
611 if (retval < 0)
612 goto error;
613 }
614 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
615 goto error;
616 }
617
618 new->fsuid = new->euid = kuid;
619
620 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
621 if (retval < 0)
622 goto error;
623
624 retval = set_cred_ucounts(new);
625 if (retval < 0)
626 goto error;
627
628 return commit_creds(new);
629
630error:
631 abort_creds(new);
632 return retval;
633}
634
635SYSCALL_DEFINE1(setuid, uid_t, uid)
636{
637 return __sys_setuid(uid);
638}
639
640
641/*
642 * This function implements a generic ability to update ruid, euid,
643 * and suid. This allows you to implement the 4.4 compatible seteuid().
644 */
645long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
646{
647 struct user_namespace *ns = current_user_ns();
648 const struct cred *old;
649 struct cred *new;
650 int retval;
651 kuid_t kruid, keuid, ksuid;
652
653 kruid = make_kuid(ns, ruid);
654 keuid = make_kuid(ns, euid);
655 ksuid = make_kuid(ns, suid);
656
657 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
658 return -EINVAL;
659
660 if ((euid != (uid_t) -1) && !uid_valid(keuid))
661 return -EINVAL;
662
663 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
664 return -EINVAL;
665
666 new = prepare_creds();
667 if (!new)
668 return -ENOMEM;
669
670 old = current_cred();
671
672 retval = -EPERM;
673 if (!ns_capable_setid(old->user_ns, CAP_SETUID)) {
674 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
675 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
676 goto error;
677 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
678 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
679 goto error;
680 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
681 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
682 goto error;
683 }
684
685 if (ruid != (uid_t) -1) {
686 new->uid = kruid;
687 if (!uid_eq(kruid, old->uid)) {
688 retval = set_user(new);
689 if (retval < 0)
690 goto error;
691 }
692 }
693 if (euid != (uid_t) -1)
694 new->euid = keuid;
695 if (suid != (uid_t) -1)
696 new->suid = ksuid;
697 new->fsuid = new->euid;
698
699 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
700 if (retval < 0)
701 goto error;
702
703 retval = set_cred_ucounts(new);
704 if (retval < 0)
705 goto error;
706
707 return commit_creds(new);
708
709error:
710 abort_creds(new);
711 return retval;
712}
713
714SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
715{
716 return __sys_setresuid(ruid, euid, suid);
717}
718
719SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
720{
721 const struct cred *cred = current_cred();
722 int retval;
723 uid_t ruid, euid, suid;
724
725 ruid = from_kuid_munged(cred->user_ns, cred->uid);
726 euid = from_kuid_munged(cred->user_ns, cred->euid);
727 suid = from_kuid_munged(cred->user_ns, cred->suid);
728
729 retval = put_user(ruid, ruidp);
730 if (!retval) {
731 retval = put_user(euid, euidp);
732 if (!retval)
733 return put_user(suid, suidp);
734 }
735 return retval;
736}
737
738/*
739 * Same as above, but for rgid, egid, sgid.
740 */
741long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
742{
743 struct user_namespace *ns = current_user_ns();
744 const struct cred *old;
745 struct cred *new;
746 int retval;
747 kgid_t krgid, kegid, ksgid;
748
749 krgid = make_kgid(ns, rgid);
750 kegid = make_kgid(ns, egid);
751 ksgid = make_kgid(ns, sgid);
752
753 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
754 return -EINVAL;
755 if ((egid != (gid_t) -1) && !gid_valid(kegid))
756 return -EINVAL;
757 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
758 return -EINVAL;
759
760 new = prepare_creds();
761 if (!new)
762 return -ENOMEM;
763 old = current_cred();
764
765 retval = -EPERM;
766 if (!ns_capable_setid(old->user_ns, CAP_SETGID)) {
767 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
768 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
769 goto error;
770 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
771 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
772 goto error;
773 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
774 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
775 goto error;
776 }
777
778 if (rgid != (gid_t) -1)
779 new->gid = krgid;
780 if (egid != (gid_t) -1)
781 new->egid = kegid;
782 if (sgid != (gid_t) -1)
783 new->sgid = ksgid;
784 new->fsgid = new->egid;
785
786 retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
787 if (retval < 0)
788 goto error;
789
790 return commit_creds(new);
791
792error:
793 abort_creds(new);
794 return retval;
795}
796
797SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
798{
799 return __sys_setresgid(rgid, egid, sgid);
800}
801
802SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
803{
804 const struct cred *cred = current_cred();
805 int retval;
806 gid_t rgid, egid, sgid;
807
808 rgid = from_kgid_munged(cred->user_ns, cred->gid);
809 egid = from_kgid_munged(cred->user_ns, cred->egid);
810 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
811
812 retval = put_user(rgid, rgidp);
813 if (!retval) {
814 retval = put_user(egid, egidp);
815 if (!retval)
816 retval = put_user(sgid, sgidp);
817 }
818
819 return retval;
820}
821
822
823/*
824 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
825 * is used for "access()" and for the NFS daemon (letting nfsd stay at
826 * whatever uid it wants to). It normally shadows "euid", except when
827 * explicitly set by setfsuid() or for access..
828 */
829long __sys_setfsuid(uid_t uid)
830{
831 const struct cred *old;
832 struct cred *new;
833 uid_t old_fsuid;
834 kuid_t kuid;
835
836 old = current_cred();
837 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
838
839 kuid = make_kuid(old->user_ns, uid);
840 if (!uid_valid(kuid))
841 return old_fsuid;
842
843 new = prepare_creds();
844 if (!new)
845 return old_fsuid;
846
847 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
848 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
849 ns_capable_setid(old->user_ns, CAP_SETUID)) {
850 if (!uid_eq(kuid, old->fsuid)) {
851 new->fsuid = kuid;
852 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
853 goto change_okay;
854 }
855 }
856
857 abort_creds(new);
858 return old_fsuid;
859
860change_okay:
861 commit_creds(new);
862 return old_fsuid;
863}
864
865SYSCALL_DEFINE1(setfsuid, uid_t, uid)
866{
867 return __sys_setfsuid(uid);
868}
869
870/*
871 * Samma på svenska..
872 */
873long __sys_setfsgid(gid_t gid)
874{
875 const struct cred *old;
876 struct cred *new;
877 gid_t old_fsgid;
878 kgid_t kgid;
879
880 old = current_cred();
881 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
882
883 kgid = make_kgid(old->user_ns, gid);
884 if (!gid_valid(kgid))
885 return old_fsgid;
886
887 new = prepare_creds();
888 if (!new)
889 return old_fsgid;
890
891 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
892 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
893 ns_capable_setid(old->user_ns, CAP_SETGID)) {
894 if (!gid_eq(kgid, old->fsgid)) {
895 new->fsgid = kgid;
896 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
897 goto change_okay;
898 }
899 }
900
901 abort_creds(new);
902 return old_fsgid;
903
904change_okay:
905 commit_creds(new);
906 return old_fsgid;
907}
908
909SYSCALL_DEFINE1(setfsgid, gid_t, gid)
910{
911 return __sys_setfsgid(gid);
912}
913#endif /* CONFIG_MULTIUSER */
914
915/**
916 * sys_getpid - return the thread group id of the current process
917 *
918 * Note, despite the name, this returns the tgid not the pid. The tgid and
919 * the pid are identical unless CLONE_THREAD was specified on clone() in
920 * which case the tgid is the same in all threads of the same group.
921 *
922 * This is SMP safe as current->tgid does not change.
923 */
924SYSCALL_DEFINE0(getpid)
925{
926 return task_tgid_vnr(current);
927}
928
929/* Thread ID - the internal kernel "pid" */
930SYSCALL_DEFINE0(gettid)
931{
932 return task_pid_vnr(current);
933}
934
935/*
936 * Accessing ->real_parent is not SMP-safe, it could
937 * change from under us. However, we can use a stale
938 * value of ->real_parent under rcu_read_lock(), see
939 * release_task()->call_rcu(delayed_put_task_struct).
940 */
941SYSCALL_DEFINE0(getppid)
942{
943 int pid;
944
945 rcu_read_lock();
946 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
947 rcu_read_unlock();
948
949 return pid;
950}
951
952SYSCALL_DEFINE0(getuid)
953{
954 /* Only we change this so SMP safe */
955 return from_kuid_munged(current_user_ns(), current_uid());
956}
957
958SYSCALL_DEFINE0(geteuid)
959{
960 /* Only we change this so SMP safe */
961 return from_kuid_munged(current_user_ns(), current_euid());
962}
963
964SYSCALL_DEFINE0(getgid)
965{
966 /* Only we change this so SMP safe */
967 return from_kgid_munged(current_user_ns(), current_gid());
968}
969
970SYSCALL_DEFINE0(getegid)
971{
972 /* Only we change this so SMP safe */
973 return from_kgid_munged(current_user_ns(), current_egid());
974}
975
976static void do_sys_times(struct tms *tms)
977{
978 u64 tgutime, tgstime, cutime, cstime;
979
980 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
981 cutime = current->signal->cutime;
982 cstime = current->signal->cstime;
983 tms->tms_utime = nsec_to_clock_t(tgutime);
984 tms->tms_stime = nsec_to_clock_t(tgstime);
985 tms->tms_cutime = nsec_to_clock_t(cutime);
986 tms->tms_cstime = nsec_to_clock_t(cstime);
987}
988
989SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
990{
991 if (tbuf) {
992 struct tms tmp;
993
994 do_sys_times(&tmp);
995 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
996 return -EFAULT;
997 }
998 force_successful_syscall_return();
999 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1000}
1001
1002#ifdef CONFIG_COMPAT
1003static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
1004{
1005 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
1006}
1007
1008COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
1009{
1010 if (tbuf) {
1011 struct tms tms;
1012 struct compat_tms tmp;
1013
1014 do_sys_times(&tms);
1015 /* Convert our struct tms to the compat version. */
1016 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
1017 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
1018 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
1019 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
1020 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
1021 return -EFAULT;
1022 }
1023 force_successful_syscall_return();
1024 return compat_jiffies_to_clock_t(jiffies);
1025}
1026#endif
1027
1028/*
1029 * This needs some heavy checking ...
1030 * I just haven't the stomach for it. I also don't fully
1031 * understand sessions/pgrp etc. Let somebody who does explain it.
1032 *
1033 * OK, I think I have the protection semantics right.... this is really
1034 * only important on a multi-user system anyway, to make sure one user
1035 * can't send a signal to a process owned by another. -TYT, 12/12/91
1036 *
1037 * !PF_FORKNOEXEC check to conform completely to POSIX.
1038 */
1039SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1040{
1041 struct task_struct *p;
1042 struct task_struct *group_leader = current->group_leader;
1043 struct pid *pgrp;
1044 int err;
1045
1046 if (!pid)
1047 pid = task_pid_vnr(group_leader);
1048 if (!pgid)
1049 pgid = pid;
1050 if (pgid < 0)
1051 return -EINVAL;
1052 rcu_read_lock();
1053
1054 /* From this point forward we keep holding onto the tasklist lock
1055 * so that our parent does not change from under us. -DaveM
1056 */
1057 write_lock_irq(&tasklist_lock);
1058
1059 err = -ESRCH;
1060 p = find_task_by_vpid(pid);
1061 if (!p)
1062 goto out;
1063
1064 err = -EINVAL;
1065 if (!thread_group_leader(p))
1066 goto out;
1067
1068 if (same_thread_group(p->real_parent, group_leader)) {
1069 err = -EPERM;
1070 if (task_session(p) != task_session(group_leader))
1071 goto out;
1072 err = -EACCES;
1073 if (!(p->flags & PF_FORKNOEXEC))
1074 goto out;
1075 } else {
1076 err = -ESRCH;
1077 if (p != group_leader)
1078 goto out;
1079 }
1080
1081 err = -EPERM;
1082 if (p->signal->leader)
1083 goto out;
1084
1085 pgrp = task_pid(p);
1086 if (pgid != pid) {
1087 struct task_struct *g;
1088
1089 pgrp = find_vpid(pgid);
1090 g = pid_task(pgrp, PIDTYPE_PGID);
1091 if (!g || task_session(g) != task_session(group_leader))
1092 goto out;
1093 }
1094
1095 err = security_task_setpgid(p, pgid);
1096 if (err)
1097 goto out;
1098
1099 if (task_pgrp(p) != pgrp)
1100 change_pid(p, PIDTYPE_PGID, pgrp);
1101
1102 err = 0;
1103out:
1104 /* All paths lead to here, thus we are safe. -DaveM */
1105 write_unlock_irq(&tasklist_lock);
1106 rcu_read_unlock();
1107 return err;
1108}
1109
1110static int do_getpgid(pid_t pid)
1111{
1112 struct task_struct *p;
1113 struct pid *grp;
1114 int retval;
1115
1116 rcu_read_lock();
1117 if (!pid)
1118 grp = task_pgrp(current);
1119 else {
1120 retval = -ESRCH;
1121 p = find_task_by_vpid(pid);
1122 if (!p)
1123 goto out;
1124 grp = task_pgrp(p);
1125 if (!grp)
1126 goto out;
1127
1128 retval = security_task_getpgid(p);
1129 if (retval)
1130 goto out;
1131 }
1132 retval = pid_vnr(grp);
1133out:
1134 rcu_read_unlock();
1135 return retval;
1136}
1137
1138SYSCALL_DEFINE1(getpgid, pid_t, pid)
1139{
1140 return do_getpgid(pid);
1141}
1142
1143#ifdef __ARCH_WANT_SYS_GETPGRP
1144
1145SYSCALL_DEFINE0(getpgrp)
1146{
1147 return do_getpgid(0);
1148}
1149
1150#endif
1151
1152SYSCALL_DEFINE1(getsid, pid_t, pid)
1153{
1154 struct task_struct *p;
1155 struct pid *sid;
1156 int retval;
1157
1158 rcu_read_lock();
1159 if (!pid)
1160 sid = task_session(current);
1161 else {
1162 retval = -ESRCH;
1163 p = find_task_by_vpid(pid);
1164 if (!p)
1165 goto out;
1166 sid = task_session(p);
1167 if (!sid)
1168 goto out;
1169
1170 retval = security_task_getsid(p);
1171 if (retval)
1172 goto out;
1173 }
1174 retval = pid_vnr(sid);
1175out:
1176 rcu_read_unlock();
1177 return retval;
1178}
1179
1180static void set_special_pids(struct pid *pid)
1181{
1182 struct task_struct *curr = current->group_leader;
1183
1184 if (task_session(curr) != pid)
1185 change_pid(curr, PIDTYPE_SID, pid);
1186
1187 if (task_pgrp(curr) != pid)
1188 change_pid(curr, PIDTYPE_PGID, pid);
1189}
1190
1191int ksys_setsid(void)
1192{
1193 struct task_struct *group_leader = current->group_leader;
1194 struct pid *sid = task_pid(group_leader);
1195 pid_t session = pid_vnr(sid);
1196 int err = -EPERM;
1197
1198 write_lock_irq(&tasklist_lock);
1199 /* Fail if I am already a session leader */
1200 if (group_leader->signal->leader)
1201 goto out;
1202
1203 /* Fail if a process group id already exists that equals the
1204 * proposed session id.
1205 */
1206 if (pid_task(sid, PIDTYPE_PGID))
1207 goto out;
1208
1209 group_leader->signal->leader = 1;
1210 set_special_pids(sid);
1211
1212 proc_clear_tty(group_leader);
1213
1214 err = session;
1215out:
1216 write_unlock_irq(&tasklist_lock);
1217 if (err > 0) {
1218 proc_sid_connector(group_leader);
1219 sched_autogroup_create_attach(group_leader);
1220 }
1221 return err;
1222}
1223
1224SYSCALL_DEFINE0(setsid)
1225{
1226 return ksys_setsid();
1227}
1228
1229DECLARE_RWSEM(uts_sem);
1230
1231#ifdef COMPAT_UTS_MACHINE
1232#define override_architecture(name) \
1233 (personality(current->personality) == PER_LINUX32 && \
1234 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1235 sizeof(COMPAT_UTS_MACHINE)))
1236#else
1237#define override_architecture(name) 0
1238#endif
1239
1240/*
1241 * Work around broken programs that cannot handle "Linux 3.0".
1242 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1243 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be
1244 * 2.6.60.
1245 */
1246static int override_release(char __user *release, size_t len)
1247{
1248 int ret = 0;
1249
1250 if (current->personality & UNAME26) {
1251 const char *rest = UTS_RELEASE;
1252 char buf[65] = { 0 };
1253 int ndots = 0;
1254 unsigned v;
1255 size_t copy;
1256
1257 while (*rest) {
1258 if (*rest == '.' && ++ndots >= 3)
1259 break;
1260 if (!isdigit(*rest) && *rest != '.')
1261 break;
1262 rest++;
1263 }
1264 v = LINUX_VERSION_PATCHLEVEL + 60;
1265 copy = clamp_t(size_t, len, 1, sizeof(buf));
1266 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1267 ret = copy_to_user(release, buf, copy + 1);
1268 }
1269 return ret;
1270}
1271
1272SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1273{
1274 struct new_utsname tmp;
1275
1276 down_read(&uts_sem);
1277 memcpy(&tmp, utsname(), sizeof(tmp));
1278 up_read(&uts_sem);
1279 if (copy_to_user(name, &tmp, sizeof(tmp)))
1280 return -EFAULT;
1281
1282 if (override_release(name->release, sizeof(name->release)))
1283 return -EFAULT;
1284 if (override_architecture(name))
1285 return -EFAULT;
1286 return 0;
1287}
1288
1289#ifdef __ARCH_WANT_SYS_OLD_UNAME
1290/*
1291 * Old cruft
1292 */
1293SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1294{
1295 struct old_utsname tmp;
1296
1297 if (!name)
1298 return -EFAULT;
1299
1300 down_read(&uts_sem);
1301 memcpy(&tmp, utsname(), sizeof(tmp));
1302 up_read(&uts_sem);
1303 if (copy_to_user(name, &tmp, sizeof(tmp)))
1304 return -EFAULT;
1305
1306 if (override_release(name->release, sizeof(name->release)))
1307 return -EFAULT;
1308 if (override_architecture(name))
1309 return -EFAULT;
1310 return 0;
1311}
1312
1313SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1314{
1315 struct oldold_utsname tmp;
1316
1317 if (!name)
1318 return -EFAULT;
1319
1320 memset(&tmp, 0, sizeof(tmp));
1321
1322 down_read(&uts_sem);
1323 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1324 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1325 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1326 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1327 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
1328 up_read(&uts_sem);
1329 if (copy_to_user(name, &tmp, sizeof(tmp)))
1330 return -EFAULT;
1331
1332 if (override_architecture(name))
1333 return -EFAULT;
1334 if (override_release(name->release, sizeof(name->release)))
1335 return -EFAULT;
1336 return 0;
1337}
1338#endif
1339
1340SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1341{
1342 int errno;
1343 char tmp[__NEW_UTS_LEN];
1344
1345 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1346 return -EPERM;
1347
1348 if (len < 0 || len > __NEW_UTS_LEN)
1349 return -EINVAL;
1350 errno = -EFAULT;
1351 if (!copy_from_user(tmp, name, len)) {
1352 struct new_utsname *u;
1353
1354 down_write(&uts_sem);
1355 u = utsname();
1356 memcpy(u->nodename, tmp, len);
1357 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1358 errno = 0;
1359 uts_proc_notify(UTS_PROC_HOSTNAME);
1360 up_write(&uts_sem);
1361 }
1362 return errno;
1363}
1364
1365#ifdef __ARCH_WANT_SYS_GETHOSTNAME
1366
1367SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1368{
1369 int i;
1370 struct new_utsname *u;
1371 char tmp[__NEW_UTS_LEN + 1];
1372
1373 if (len < 0)
1374 return -EINVAL;
1375 down_read(&uts_sem);
1376 u = utsname();
1377 i = 1 + strlen(u->nodename);
1378 if (i > len)
1379 i = len;
1380 memcpy(tmp, u->nodename, i);
1381 up_read(&uts_sem);
1382 if (copy_to_user(name, tmp, i))
1383 return -EFAULT;
1384 return 0;
1385}
1386
1387#endif
1388
1389/*
1390 * Only setdomainname; getdomainname can be implemented by calling
1391 * uname()
1392 */
1393SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1394{
1395 int errno;
1396 char tmp[__NEW_UTS_LEN];
1397
1398 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1399 return -EPERM;
1400 if (len < 0 || len > __NEW_UTS_LEN)
1401 return -EINVAL;
1402
1403 errno = -EFAULT;
1404 if (!copy_from_user(tmp, name, len)) {
1405 struct new_utsname *u;
1406
1407 down_write(&uts_sem);
1408 u = utsname();
1409 memcpy(u->domainname, tmp, len);
1410 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1411 errno = 0;
1412 uts_proc_notify(UTS_PROC_DOMAINNAME);
1413 up_write(&uts_sem);
1414 }
1415 return errno;
1416}
1417
1418SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1419{
1420 struct rlimit value;
1421 int ret;
1422
1423 ret = do_prlimit(current, resource, NULL, &value);
1424 if (!ret)
1425 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1426
1427 return ret;
1428}
1429
1430#ifdef CONFIG_COMPAT
1431
1432COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1433 struct compat_rlimit __user *, rlim)
1434{
1435 struct rlimit r;
1436 struct compat_rlimit r32;
1437
1438 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1439 return -EFAULT;
1440
1441 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1442 r.rlim_cur = RLIM_INFINITY;
1443 else
1444 r.rlim_cur = r32.rlim_cur;
1445 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1446 r.rlim_max = RLIM_INFINITY;
1447 else
1448 r.rlim_max = r32.rlim_max;
1449 return do_prlimit(current, resource, &r, NULL);
1450}
1451
1452COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1453 struct compat_rlimit __user *, rlim)
1454{
1455 struct rlimit r;
1456 int ret;
1457
1458 ret = do_prlimit(current, resource, NULL, &r);
1459 if (!ret) {
1460 struct compat_rlimit r32;
1461 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1462 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1463 else
1464 r32.rlim_cur = r.rlim_cur;
1465 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1466 r32.rlim_max = COMPAT_RLIM_INFINITY;
1467 else
1468 r32.rlim_max = r.rlim_max;
1469
1470 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1471 return -EFAULT;
1472 }
1473 return ret;
1474}
1475
1476#endif
1477
1478#ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1479
1480/*
1481 * Back compatibility for getrlimit. Needed for some apps.
1482 */
1483SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1484 struct rlimit __user *, rlim)
1485{
1486 struct rlimit x;
1487 if (resource >= RLIM_NLIMITS)
1488 return -EINVAL;
1489
1490 resource = array_index_nospec(resource, RLIM_NLIMITS);
1491 task_lock(current->group_leader);
1492 x = current->signal->rlim[resource];
1493 task_unlock(current->group_leader);
1494 if (x.rlim_cur > 0x7FFFFFFF)
1495 x.rlim_cur = 0x7FFFFFFF;
1496 if (x.rlim_max > 0x7FFFFFFF)
1497 x.rlim_max = 0x7FFFFFFF;
1498 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1499}
1500
1501#ifdef CONFIG_COMPAT
1502COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1503 struct compat_rlimit __user *, rlim)
1504{
1505 struct rlimit r;
1506
1507 if (resource >= RLIM_NLIMITS)
1508 return -EINVAL;
1509
1510 resource = array_index_nospec(resource, RLIM_NLIMITS);
1511 task_lock(current->group_leader);
1512 r = current->signal->rlim[resource];
1513 task_unlock(current->group_leader);
1514 if (r.rlim_cur > 0x7FFFFFFF)
1515 r.rlim_cur = 0x7FFFFFFF;
1516 if (r.rlim_max > 0x7FFFFFFF)
1517 r.rlim_max = 0x7FFFFFFF;
1518
1519 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1520 put_user(r.rlim_max, &rlim->rlim_max))
1521 return -EFAULT;
1522 return 0;
1523}
1524#endif
1525
1526#endif
1527
1528static inline bool rlim64_is_infinity(__u64 rlim64)
1529{
1530#if BITS_PER_LONG < 64
1531 return rlim64 >= ULONG_MAX;
1532#else
1533 return rlim64 == RLIM64_INFINITY;
1534#endif
1535}
1536
1537static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1538{
1539 if (rlim->rlim_cur == RLIM_INFINITY)
1540 rlim64->rlim_cur = RLIM64_INFINITY;
1541 else
1542 rlim64->rlim_cur = rlim->rlim_cur;
1543 if (rlim->rlim_max == RLIM_INFINITY)
1544 rlim64->rlim_max = RLIM64_INFINITY;
1545 else
1546 rlim64->rlim_max = rlim->rlim_max;
1547}
1548
1549static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1550{
1551 if (rlim64_is_infinity(rlim64->rlim_cur))
1552 rlim->rlim_cur = RLIM_INFINITY;
1553 else
1554 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1555 if (rlim64_is_infinity(rlim64->rlim_max))
1556 rlim->rlim_max = RLIM_INFINITY;
1557 else
1558 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1559}
1560
1561/* make sure you are allowed to change @tsk limits before calling this */
1562int do_prlimit(struct task_struct *tsk, unsigned int resource,
1563 struct rlimit *new_rlim, struct rlimit *old_rlim)
1564{
1565 struct rlimit *rlim;
1566 int retval = 0;
1567
1568 if (resource >= RLIM_NLIMITS)
1569 return -EINVAL;
1570 if (new_rlim) {
1571 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1572 return -EINVAL;
1573 if (resource == RLIMIT_NOFILE &&
1574 new_rlim->rlim_max > sysctl_nr_open)
1575 return -EPERM;
1576 }
1577
1578 /* protect tsk->signal and tsk->sighand from disappearing */
1579 read_lock(&tasklist_lock);
1580 if (!tsk->sighand) {
1581 retval = -ESRCH;
1582 goto out;
1583 }
1584
1585 rlim = tsk->signal->rlim + resource;
1586 task_lock(tsk->group_leader);
1587 if (new_rlim) {
1588 /* Keep the capable check against init_user_ns until
1589 cgroups can contain all limits */
1590 if (new_rlim->rlim_max > rlim->rlim_max &&
1591 !capable(CAP_SYS_RESOURCE))
1592 retval = -EPERM;
1593 if (!retval)
1594 retval = security_task_setrlimit(tsk, resource, new_rlim);
1595 }
1596 if (!retval) {
1597 if (old_rlim)
1598 *old_rlim = *rlim;
1599 if (new_rlim)
1600 *rlim = *new_rlim;
1601 }
1602 task_unlock(tsk->group_leader);
1603
1604 /*
1605 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
1606 * infinite. In case of RLIM_INFINITY the posix CPU timer code
1607 * ignores the rlimit.
1608 */
1609 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1610 new_rlim->rlim_cur != RLIM_INFINITY &&
1611 IS_ENABLED(CONFIG_POSIX_TIMERS))
1612 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1613out:
1614 read_unlock(&tasklist_lock);
1615 return retval;
1616}
1617
1618/* rcu lock must be held */
1619static int check_prlimit_permission(struct task_struct *task,
1620 unsigned int flags)
1621{
1622 const struct cred *cred = current_cred(), *tcred;
1623 bool id_match;
1624
1625 if (current == task)
1626 return 0;
1627
1628 tcred = __task_cred(task);
1629 id_match = (uid_eq(cred->uid, tcred->euid) &&
1630 uid_eq(cred->uid, tcred->suid) &&
1631 uid_eq(cred->uid, tcred->uid) &&
1632 gid_eq(cred->gid, tcred->egid) &&
1633 gid_eq(cred->gid, tcred->sgid) &&
1634 gid_eq(cred->gid, tcred->gid));
1635 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1636 return -EPERM;
1637
1638 return security_task_prlimit(cred, tcred, flags);
1639}
1640
1641SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1642 const struct rlimit64 __user *, new_rlim,
1643 struct rlimit64 __user *, old_rlim)
1644{
1645 struct rlimit64 old64, new64;
1646 struct rlimit old, new;
1647 struct task_struct *tsk;
1648 unsigned int checkflags = 0;
1649 int ret;
1650
1651 if (old_rlim)
1652 checkflags |= LSM_PRLIMIT_READ;
1653
1654 if (new_rlim) {
1655 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1656 return -EFAULT;
1657 rlim64_to_rlim(&new64, &new);
1658 checkflags |= LSM_PRLIMIT_WRITE;
1659 }
1660
1661 rcu_read_lock();
1662 tsk = pid ? find_task_by_vpid(pid) : current;
1663 if (!tsk) {
1664 rcu_read_unlock();
1665 return -ESRCH;
1666 }
1667 ret = check_prlimit_permission(tsk, checkflags);
1668 if (ret) {
1669 rcu_read_unlock();
1670 return ret;
1671 }
1672 get_task_struct(tsk);
1673 rcu_read_unlock();
1674
1675 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1676 old_rlim ? &old : NULL);
1677
1678 if (!ret && old_rlim) {
1679 rlim_to_rlim64(&old, &old64);
1680 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1681 ret = -EFAULT;
1682 }
1683
1684 put_task_struct(tsk);
1685 return ret;
1686}
1687
1688SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1689{
1690 struct rlimit new_rlim;
1691
1692 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1693 return -EFAULT;
1694 return do_prlimit(current, resource, &new_rlim, NULL);
1695}
1696
1697/*
1698 * It would make sense to put struct rusage in the task_struct,
1699 * except that would make the task_struct be *really big*. After
1700 * task_struct gets moved into malloc'ed memory, it would
1701 * make sense to do this. It will make moving the rest of the information
1702 * a lot simpler! (Which we're not doing right now because we're not
1703 * measuring them yet).
1704 *
1705 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1706 * races with threads incrementing their own counters. But since word
1707 * reads are atomic, we either get new values or old values and we don't
1708 * care which for the sums. We always take the siglock to protect reading
1709 * the c* fields from p->signal from races with exit.c updating those
1710 * fields when reaping, so a sample either gets all the additions of a
1711 * given child after it's reaped, or none so this sample is before reaping.
1712 *
1713 * Locking:
1714 * We need to take the siglock for CHILDEREN, SELF and BOTH
1715 * for the cases current multithreaded, non-current single threaded
1716 * non-current multithreaded. Thread traversal is now safe with
1717 * the siglock held.
1718 * Strictly speaking, we donot need to take the siglock if we are current and
1719 * single threaded, as no one else can take our signal_struct away, no one
1720 * else can reap the children to update signal->c* counters, and no one else
1721 * can race with the signal-> fields. If we do not take any lock, the
1722 * signal-> fields could be read out of order while another thread was just
1723 * exiting. So we should place a read memory barrier when we avoid the lock.
1724 * On the writer side, write memory barrier is implied in __exit_signal
1725 * as __exit_signal releases the siglock spinlock after updating the signal->
1726 * fields. But we don't do this yet to keep things simple.
1727 *
1728 */
1729
1730static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1731{
1732 r->ru_nvcsw += t->nvcsw;
1733 r->ru_nivcsw += t->nivcsw;
1734 r->ru_minflt += t->min_flt;
1735 r->ru_majflt += t->maj_flt;
1736 r->ru_inblock += task_io_get_inblock(t);
1737 r->ru_oublock += task_io_get_oublock(t);
1738}
1739
1740void getrusage(struct task_struct *p, int who, struct rusage *r)
1741{
1742 struct task_struct *t;
1743 unsigned long flags;
1744 u64 tgutime, tgstime, utime, stime;
1745 unsigned long maxrss = 0;
1746
1747 memset((char *)r, 0, sizeof (*r));
1748 utime = stime = 0;
1749
1750 if (who == RUSAGE_THREAD) {
1751 task_cputime_adjusted(current, &utime, &stime);
1752 accumulate_thread_rusage(p, r);
1753 maxrss = p->signal->maxrss;
1754 goto out;
1755 }
1756
1757 if (!lock_task_sighand(p, &flags))
1758 return;
1759
1760 switch (who) {
1761 case RUSAGE_BOTH:
1762 case RUSAGE_CHILDREN:
1763 utime = p->signal->cutime;
1764 stime = p->signal->cstime;
1765 r->ru_nvcsw = p->signal->cnvcsw;
1766 r->ru_nivcsw = p->signal->cnivcsw;
1767 r->ru_minflt = p->signal->cmin_flt;
1768 r->ru_majflt = p->signal->cmaj_flt;
1769 r->ru_inblock = p->signal->cinblock;
1770 r->ru_oublock = p->signal->coublock;
1771 maxrss = p->signal->cmaxrss;
1772
1773 if (who == RUSAGE_CHILDREN)
1774 break;
1775 fallthrough;
1776
1777 case RUSAGE_SELF:
1778 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1779 utime += tgutime;
1780 stime += tgstime;
1781 r->ru_nvcsw += p->signal->nvcsw;
1782 r->ru_nivcsw += p->signal->nivcsw;
1783 r->ru_minflt += p->signal->min_flt;
1784 r->ru_majflt += p->signal->maj_flt;
1785 r->ru_inblock += p->signal->inblock;
1786 r->ru_oublock += p->signal->oublock;
1787 if (maxrss < p->signal->maxrss)
1788 maxrss = p->signal->maxrss;
1789 t = p;
1790 do {
1791 accumulate_thread_rusage(t, r);
1792 } while_each_thread(p, t);
1793 break;
1794
1795 default:
1796 BUG();
1797 }
1798 unlock_task_sighand(p, &flags);
1799
1800out:
1801 r->ru_utime = ns_to_kernel_old_timeval(utime);
1802 r->ru_stime = ns_to_kernel_old_timeval(stime);
1803
1804 if (who != RUSAGE_CHILDREN) {
1805 struct mm_struct *mm = get_task_mm(p);
1806
1807 if (mm) {
1808 setmax_mm_hiwater_rss(&maxrss, mm);
1809 mmput(mm);
1810 }
1811 }
1812 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1813}
1814
1815SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1816{
1817 struct rusage r;
1818
1819 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1820 who != RUSAGE_THREAD)
1821 return -EINVAL;
1822
1823 getrusage(current, who, &r);
1824 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1825}
1826
1827#ifdef CONFIG_COMPAT
1828COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1829{
1830 struct rusage r;
1831
1832 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1833 who != RUSAGE_THREAD)
1834 return -EINVAL;
1835
1836 getrusage(current, who, &r);
1837 return put_compat_rusage(&r, ru);
1838}
1839#endif
1840
1841SYSCALL_DEFINE1(umask, int, mask)
1842{
1843 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1844 return mask;
1845}
1846
1847static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1848{
1849 struct fd exe;
1850 struct inode *inode;
1851 int err;
1852
1853 exe = fdget(fd);
1854 if (!exe.file)
1855 return -EBADF;
1856
1857 inode = file_inode(exe.file);
1858
1859 /*
1860 * Because the original mm->exe_file points to executable file, make
1861 * sure that this one is executable as well, to avoid breaking an
1862 * overall picture.
1863 */
1864 err = -EACCES;
1865 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
1866 goto exit;
1867
1868 err = file_permission(exe.file, MAY_EXEC);
1869 if (err)
1870 goto exit;
1871
1872 err = replace_mm_exe_file(mm, exe.file);
1873exit:
1874 fdput(exe);
1875 return err;
1876}
1877
1878/*
1879 * Check arithmetic relations of passed addresses.
1880 *
1881 * WARNING: we don't require any capability here so be very careful
1882 * in what is allowed for modification from userspace.
1883 */
1884static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
1885{
1886 unsigned long mmap_max_addr = TASK_SIZE;
1887 int error = -EINVAL, i;
1888
1889 static const unsigned char offsets[] = {
1890 offsetof(struct prctl_mm_map, start_code),
1891 offsetof(struct prctl_mm_map, end_code),
1892 offsetof(struct prctl_mm_map, start_data),
1893 offsetof(struct prctl_mm_map, end_data),
1894 offsetof(struct prctl_mm_map, start_brk),
1895 offsetof(struct prctl_mm_map, brk),
1896 offsetof(struct prctl_mm_map, start_stack),
1897 offsetof(struct prctl_mm_map, arg_start),
1898 offsetof(struct prctl_mm_map, arg_end),
1899 offsetof(struct prctl_mm_map, env_start),
1900 offsetof(struct prctl_mm_map, env_end),
1901 };
1902
1903 /*
1904 * Make sure the members are not somewhere outside
1905 * of allowed address space.
1906 */
1907 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1908 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1909
1910 if ((unsigned long)val >= mmap_max_addr ||
1911 (unsigned long)val < mmap_min_addr)
1912 goto out;
1913 }
1914
1915 /*
1916 * Make sure the pairs are ordered.
1917 */
1918#define __prctl_check_order(__m1, __op, __m2) \
1919 ((unsigned long)prctl_map->__m1 __op \
1920 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1921 error = __prctl_check_order(start_code, <, end_code);
1922 error |= __prctl_check_order(start_data,<=, end_data);
1923 error |= __prctl_check_order(start_brk, <=, brk);
1924 error |= __prctl_check_order(arg_start, <=, arg_end);
1925 error |= __prctl_check_order(env_start, <=, env_end);
1926 if (error)
1927 goto out;
1928#undef __prctl_check_order
1929
1930 error = -EINVAL;
1931
1932 /*
1933 * Neither we should allow to override limits if they set.
1934 */
1935 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1936 prctl_map->start_brk, prctl_map->end_data,
1937 prctl_map->start_data))
1938 goto out;
1939
1940 error = 0;
1941out:
1942 return error;
1943}
1944
1945#ifdef CONFIG_CHECKPOINT_RESTORE
1946static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1947{
1948 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1949 unsigned long user_auxv[AT_VECTOR_SIZE];
1950 struct mm_struct *mm = current->mm;
1951 int error;
1952
1953 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1954 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1955
1956 if (opt == PR_SET_MM_MAP_SIZE)
1957 return put_user((unsigned int)sizeof(prctl_map),
1958 (unsigned int __user *)addr);
1959
1960 if (data_size != sizeof(prctl_map))
1961 return -EINVAL;
1962
1963 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1964 return -EFAULT;
1965
1966 error = validate_prctl_map_addr(&prctl_map);
1967 if (error)
1968 return error;
1969
1970 if (prctl_map.auxv_size) {
1971 /*
1972 * Someone is trying to cheat the auxv vector.
1973 */
1974 if (!prctl_map.auxv ||
1975 prctl_map.auxv_size > sizeof(mm->saved_auxv))
1976 return -EINVAL;
1977
1978 memset(user_auxv, 0, sizeof(user_auxv));
1979 if (copy_from_user(user_auxv,
1980 (const void __user *)prctl_map.auxv,
1981 prctl_map.auxv_size))
1982 return -EFAULT;
1983
1984 /* Last entry must be AT_NULL as specification requires */
1985 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
1986 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
1987 }
1988
1989 if (prctl_map.exe_fd != (u32)-1) {
1990 /*
1991 * Check if the current user is checkpoint/restore capable.
1992 * At the time of this writing, it checks for CAP_SYS_ADMIN
1993 * or CAP_CHECKPOINT_RESTORE.
1994 * Note that a user with access to ptrace can masquerade an
1995 * arbitrary program as any executable, even setuid ones.
1996 * This may have implications in the tomoyo subsystem.
1997 */
1998 if (!checkpoint_restore_ns_capable(current_user_ns()))
1999 return -EPERM;
2000
2001 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
2002 if (error)
2003 return error;
2004 }
2005
2006 /*
2007 * arg_lock protects concurrent updates but we still need mmap_lock for
2008 * read to exclude races with sys_brk.
2009 */
2010 mmap_read_lock(mm);
2011
2012 /*
2013 * We don't validate if these members are pointing to
2014 * real present VMAs because application may have correspond
2015 * VMAs already unmapped and kernel uses these members for statistics
2016 * output in procfs mostly, except
2017 *
2018 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups
2019 * for VMAs when updating these members so anything wrong written
2020 * here cause kernel to swear at userspace program but won't lead
2021 * to any problem in kernel itself
2022 */
2023
2024 spin_lock(&mm->arg_lock);
2025 mm->start_code = prctl_map.start_code;
2026 mm->end_code = prctl_map.end_code;
2027 mm->start_data = prctl_map.start_data;
2028 mm->end_data = prctl_map.end_data;
2029 mm->start_brk = prctl_map.start_brk;
2030 mm->brk = prctl_map.brk;
2031 mm->start_stack = prctl_map.start_stack;
2032 mm->arg_start = prctl_map.arg_start;
2033 mm->arg_end = prctl_map.arg_end;
2034 mm->env_start = prctl_map.env_start;
2035 mm->env_end = prctl_map.env_end;
2036 spin_unlock(&mm->arg_lock);
2037
2038 /*
2039 * Note this update of @saved_auxv is lockless thus
2040 * if someone reads this member in procfs while we're
2041 * updating -- it may get partly updated results. It's
2042 * known and acceptable trade off: we leave it as is to
2043 * not introduce additional locks here making the kernel
2044 * more complex.
2045 */
2046 if (prctl_map.auxv_size)
2047 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2048
2049 mmap_read_unlock(mm);
2050 return 0;
2051}
2052#endif /* CONFIG_CHECKPOINT_RESTORE */
2053
2054static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2055 unsigned long len)
2056{
2057 /*
2058 * This doesn't move the auxiliary vector itself since it's pinned to
2059 * mm_struct, but it permits filling the vector with new values. It's
2060 * up to the caller to provide sane values here, otherwise userspace
2061 * tools which use this vector might be unhappy.
2062 */
2063 unsigned long user_auxv[AT_VECTOR_SIZE] = {};
2064
2065 if (len > sizeof(user_auxv))
2066 return -EINVAL;
2067
2068 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2069 return -EFAULT;
2070
2071 /* Make sure the last entry is always AT_NULL */
2072 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2073 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2074
2075 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2076
2077 task_lock(current);
2078 memcpy(mm->saved_auxv, user_auxv, len);
2079 task_unlock(current);
2080
2081 return 0;
2082}
2083
2084static int prctl_set_mm(int opt, unsigned long addr,
2085 unsigned long arg4, unsigned long arg5)
2086{
2087 struct mm_struct *mm = current->mm;
2088 struct prctl_mm_map prctl_map = {
2089 .auxv = NULL,
2090 .auxv_size = 0,
2091 .exe_fd = -1,
2092 };
2093 struct vm_area_struct *vma;
2094 int error;
2095
2096 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2097 opt != PR_SET_MM_MAP &&
2098 opt != PR_SET_MM_MAP_SIZE)))
2099 return -EINVAL;
2100
2101#ifdef CONFIG_CHECKPOINT_RESTORE
2102 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2103 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2104#endif
2105
2106 if (!capable(CAP_SYS_RESOURCE))
2107 return -EPERM;
2108
2109 if (opt == PR_SET_MM_EXE_FILE)
2110 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
2111
2112 if (opt == PR_SET_MM_AUXV)
2113 return prctl_set_auxv(mm, addr, arg4);
2114
2115 if (addr >= TASK_SIZE || addr < mmap_min_addr)
2116 return -EINVAL;
2117
2118 error = -EINVAL;
2119
2120 /*
2121 * arg_lock protects concurrent updates of arg boundaries, we need
2122 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
2123 * validation.
2124 */
2125 mmap_read_lock(mm);
2126 vma = find_vma(mm, addr);
2127
2128 spin_lock(&mm->arg_lock);
2129 prctl_map.start_code = mm->start_code;
2130 prctl_map.end_code = mm->end_code;
2131 prctl_map.start_data = mm->start_data;
2132 prctl_map.end_data = mm->end_data;
2133 prctl_map.start_brk = mm->start_brk;
2134 prctl_map.brk = mm->brk;
2135 prctl_map.start_stack = mm->start_stack;
2136 prctl_map.arg_start = mm->arg_start;
2137 prctl_map.arg_end = mm->arg_end;
2138 prctl_map.env_start = mm->env_start;
2139 prctl_map.env_end = mm->env_end;
2140
2141 switch (opt) {
2142 case PR_SET_MM_START_CODE:
2143 prctl_map.start_code = addr;
2144 break;
2145 case PR_SET_MM_END_CODE:
2146 prctl_map.end_code = addr;
2147 break;
2148 case PR_SET_MM_START_DATA:
2149 prctl_map.start_data = addr;
2150 break;
2151 case PR_SET_MM_END_DATA:
2152 prctl_map.end_data = addr;
2153 break;
2154 case PR_SET_MM_START_STACK:
2155 prctl_map.start_stack = addr;
2156 break;
2157 case PR_SET_MM_START_BRK:
2158 prctl_map.start_brk = addr;
2159 break;
2160 case PR_SET_MM_BRK:
2161 prctl_map.brk = addr;
2162 break;
2163 case PR_SET_MM_ARG_START:
2164 prctl_map.arg_start = addr;
2165 break;
2166 case PR_SET_MM_ARG_END:
2167 prctl_map.arg_end = addr;
2168 break;
2169 case PR_SET_MM_ENV_START:
2170 prctl_map.env_start = addr;
2171 break;
2172 case PR_SET_MM_ENV_END:
2173 prctl_map.env_end = addr;
2174 break;
2175 default:
2176 goto out;
2177 }
2178
2179 error = validate_prctl_map_addr(&prctl_map);
2180 if (error)
2181 goto out;
2182
2183 switch (opt) {
2184 /*
2185 * If command line arguments and environment
2186 * are placed somewhere else on stack, we can
2187 * set them up here, ARG_START/END to setup
2188 * command line arguments and ENV_START/END
2189 * for environment.
2190 */
2191 case PR_SET_MM_START_STACK:
2192 case PR_SET_MM_ARG_START:
2193 case PR_SET_MM_ARG_END:
2194 case PR_SET_MM_ENV_START:
2195 case PR_SET_MM_ENV_END:
2196 if (!vma) {
2197 error = -EFAULT;
2198 goto out;
2199 }
2200 }
2201
2202 mm->start_code = prctl_map.start_code;
2203 mm->end_code = prctl_map.end_code;
2204 mm->start_data = prctl_map.start_data;
2205 mm->end_data = prctl_map.end_data;
2206 mm->start_brk = prctl_map.start_brk;
2207 mm->brk = prctl_map.brk;
2208 mm->start_stack = prctl_map.start_stack;
2209 mm->arg_start = prctl_map.arg_start;
2210 mm->arg_end = prctl_map.arg_end;
2211 mm->env_start = prctl_map.env_start;
2212 mm->env_end = prctl_map.env_end;
2213
2214 error = 0;
2215out:
2216 spin_unlock(&mm->arg_lock);
2217 mmap_read_unlock(mm);
2218 return error;
2219}
2220
2221#ifdef CONFIG_CHECKPOINT_RESTORE
2222static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2223{
2224 return put_user(me->clear_child_tid, tid_addr);
2225}
2226#else
2227static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2228{
2229 return -EINVAL;
2230}
2231#endif
2232
2233static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2234{
2235 /*
2236 * If task has has_child_subreaper - all its descendants
2237 * already have these flag too and new descendants will
2238 * inherit it on fork, skip them.
2239 *
2240 * If we've found child_reaper - skip descendants in
2241 * it's subtree as they will never get out pidns.
2242 */
2243 if (p->signal->has_child_subreaper ||
2244 is_child_reaper(task_pid(p)))
2245 return 0;
2246
2247 p->signal->has_child_subreaper = 1;
2248 return 1;
2249}
2250
2251int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
2252{
2253 return -EINVAL;
2254}
2255
2256int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2257 unsigned long ctrl)
2258{
2259 return -EINVAL;
2260}
2261
2262#define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
2263
2264SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2265 unsigned long, arg4, unsigned long, arg5)
2266{
2267 struct task_struct *me = current;
2268 unsigned char comm[sizeof(me->comm)];
2269 long error;
2270
2271 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2272 if (error != -ENOSYS)
2273 return error;
2274
2275 error = 0;
2276 switch (option) {
2277 case PR_SET_PDEATHSIG:
2278 if (!valid_signal(arg2)) {
2279 error = -EINVAL;
2280 break;
2281 }
2282 me->pdeath_signal = arg2;
2283 break;
2284 case PR_GET_PDEATHSIG:
2285 error = put_user(me->pdeath_signal, (int __user *)arg2);
2286 break;
2287 case PR_GET_DUMPABLE:
2288 error = get_dumpable(me->mm);
2289 break;
2290 case PR_SET_DUMPABLE:
2291 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2292 error = -EINVAL;
2293 break;
2294 }
2295 set_dumpable(me->mm, arg2);
2296 break;
2297
2298 case PR_SET_UNALIGN:
2299 error = SET_UNALIGN_CTL(me, arg2);
2300 break;
2301 case PR_GET_UNALIGN:
2302 error = GET_UNALIGN_CTL(me, arg2);
2303 break;
2304 case PR_SET_FPEMU:
2305 error = SET_FPEMU_CTL(me, arg2);
2306 break;
2307 case PR_GET_FPEMU:
2308 error = GET_FPEMU_CTL(me, arg2);
2309 break;
2310 case PR_SET_FPEXC:
2311 error = SET_FPEXC_CTL(me, arg2);
2312 break;
2313 case PR_GET_FPEXC:
2314 error = GET_FPEXC_CTL(me, arg2);
2315 break;
2316 case PR_GET_TIMING:
2317 error = PR_TIMING_STATISTICAL;
2318 break;
2319 case PR_SET_TIMING:
2320 if (arg2 != PR_TIMING_STATISTICAL)
2321 error = -EINVAL;
2322 break;
2323 case PR_SET_NAME:
2324 comm[sizeof(me->comm) - 1] = 0;
2325 if (strncpy_from_user(comm, (char __user *)arg2,
2326 sizeof(me->comm) - 1) < 0)
2327 return -EFAULT;
2328 set_task_comm(me, comm);
2329 proc_comm_connector(me);
2330 break;
2331 case PR_GET_NAME:
2332 get_task_comm(comm, me);
2333 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2334 return -EFAULT;
2335 break;
2336 case PR_GET_ENDIAN:
2337 error = GET_ENDIAN(me, arg2);
2338 break;
2339 case PR_SET_ENDIAN:
2340 error = SET_ENDIAN(me, arg2);
2341 break;
2342 case PR_GET_SECCOMP:
2343 error = prctl_get_seccomp();
2344 break;
2345 case PR_SET_SECCOMP:
2346 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2347 break;
2348 case PR_GET_TSC:
2349 error = GET_TSC_CTL(arg2);
2350 break;
2351 case PR_SET_TSC:
2352 error = SET_TSC_CTL(arg2);
2353 break;
2354 case PR_TASK_PERF_EVENTS_DISABLE:
2355 error = perf_event_task_disable();
2356 break;
2357 case PR_TASK_PERF_EVENTS_ENABLE:
2358 error = perf_event_task_enable();
2359 break;
2360 case PR_GET_TIMERSLACK:
2361 if (current->timer_slack_ns > ULONG_MAX)
2362 error = ULONG_MAX;
2363 else
2364 error = current->timer_slack_ns;
2365 break;
2366 case PR_SET_TIMERSLACK:
2367 if (arg2 <= 0)
2368 current->timer_slack_ns =
2369 current->default_timer_slack_ns;
2370 else
2371 current->timer_slack_ns = arg2;
2372 break;
2373 case PR_MCE_KILL:
2374 if (arg4 | arg5)
2375 return -EINVAL;
2376 switch (arg2) {
2377 case PR_MCE_KILL_CLEAR:
2378 if (arg3 != 0)
2379 return -EINVAL;
2380 current->flags &= ~PF_MCE_PROCESS;
2381 break;
2382 case PR_MCE_KILL_SET:
2383 current->flags |= PF_MCE_PROCESS;
2384 if (arg3 == PR_MCE_KILL_EARLY)
2385 current->flags |= PF_MCE_EARLY;
2386 else if (arg3 == PR_MCE_KILL_LATE)
2387 current->flags &= ~PF_MCE_EARLY;
2388 else if (arg3 == PR_MCE_KILL_DEFAULT)
2389 current->flags &=
2390 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2391 else
2392 return -EINVAL;
2393 break;
2394 default:
2395 return -EINVAL;
2396 }
2397 break;
2398 case PR_MCE_KILL_GET:
2399 if (arg2 | arg3 | arg4 | arg5)
2400 return -EINVAL;
2401 if (current->flags & PF_MCE_PROCESS)
2402 error = (current->flags & PF_MCE_EARLY) ?
2403 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2404 else
2405 error = PR_MCE_KILL_DEFAULT;
2406 break;
2407 case PR_SET_MM:
2408 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2409 break;
2410 case PR_GET_TID_ADDRESS:
2411 error = prctl_get_tid_address(me, (int __user * __user *)arg2);
2412 break;
2413 case PR_SET_CHILD_SUBREAPER:
2414 me->signal->is_child_subreaper = !!arg2;
2415 if (!arg2)
2416 break;
2417
2418 walk_process_tree(me, propagate_has_child_subreaper, NULL);
2419 break;
2420 case PR_GET_CHILD_SUBREAPER:
2421 error = put_user(me->signal->is_child_subreaper,
2422 (int __user *)arg2);
2423 break;
2424 case PR_SET_NO_NEW_PRIVS:
2425 if (arg2 != 1 || arg3 || arg4 || arg5)
2426 return -EINVAL;
2427
2428 task_set_no_new_privs(current);
2429 break;
2430 case PR_GET_NO_NEW_PRIVS:
2431 if (arg2 || arg3 || arg4 || arg5)
2432 return -EINVAL;
2433 return task_no_new_privs(current) ? 1 : 0;
2434 case PR_GET_THP_DISABLE:
2435 if (arg2 || arg3 || arg4 || arg5)
2436 return -EINVAL;
2437 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
2438 break;
2439 case PR_SET_THP_DISABLE:
2440 if (arg3 || arg4 || arg5)
2441 return -EINVAL;
2442 if (mmap_write_lock_killable(me->mm))
2443 return -EINTR;
2444 if (arg2)
2445 set_bit(MMF_DISABLE_THP, &me->mm->flags);
2446 else
2447 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
2448 mmap_write_unlock(me->mm);
2449 break;
2450 case PR_MPX_ENABLE_MANAGEMENT:
2451 case PR_MPX_DISABLE_MANAGEMENT:
2452 /* No longer implemented: */
2453 return -EINVAL;
2454 case PR_SET_FP_MODE:
2455 error = SET_FP_MODE(me, arg2);
2456 break;
2457 case PR_GET_FP_MODE:
2458 error = GET_FP_MODE(me);
2459 break;
2460 case PR_SVE_SET_VL:
2461 error = SVE_SET_VL(arg2);
2462 break;
2463 case PR_SVE_GET_VL:
2464 error = SVE_GET_VL();
2465 break;
2466 case PR_GET_SPECULATION_CTRL:
2467 if (arg3 || arg4 || arg5)
2468 return -EINVAL;
2469 error = arch_prctl_spec_ctrl_get(me, arg2);
2470 break;
2471 case PR_SET_SPECULATION_CTRL:
2472 if (arg4 || arg5)
2473 return -EINVAL;
2474 error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
2475 break;
2476 case PR_PAC_RESET_KEYS:
2477 if (arg3 || arg4 || arg5)
2478 return -EINVAL;
2479 error = PAC_RESET_KEYS(me, arg2);
2480 break;
2481 case PR_PAC_SET_ENABLED_KEYS:
2482 if (arg4 || arg5)
2483 return -EINVAL;
2484 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3);
2485 break;
2486 case PR_PAC_GET_ENABLED_KEYS:
2487 if (arg2 || arg3 || arg4 || arg5)
2488 return -EINVAL;
2489 error = PAC_GET_ENABLED_KEYS(me);
2490 break;
2491 case PR_SET_TAGGED_ADDR_CTRL:
2492 if (arg3 || arg4 || arg5)
2493 return -EINVAL;
2494 error = SET_TAGGED_ADDR_CTRL(arg2);
2495 break;
2496 case PR_GET_TAGGED_ADDR_CTRL:
2497 if (arg2 || arg3 || arg4 || arg5)
2498 return -EINVAL;
2499 error = GET_TAGGED_ADDR_CTRL();
2500 break;
2501 case PR_SET_IO_FLUSHER:
2502 if (!capable(CAP_SYS_RESOURCE))
2503 return -EPERM;
2504
2505 if (arg3 || arg4 || arg5)
2506 return -EINVAL;
2507
2508 if (arg2 == 1)
2509 current->flags |= PR_IO_FLUSHER;
2510 else if (!arg2)
2511 current->flags &= ~PR_IO_FLUSHER;
2512 else
2513 return -EINVAL;
2514 break;
2515 case PR_GET_IO_FLUSHER:
2516 if (!capable(CAP_SYS_RESOURCE))
2517 return -EPERM;
2518
2519 if (arg2 || arg3 || arg4 || arg5)
2520 return -EINVAL;
2521
2522 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
2523 break;
2524 case PR_SET_SYSCALL_USER_DISPATCH:
2525 error = set_syscall_user_dispatch(arg2, arg3, arg4,
2526 (char __user *) arg5);
2527 break;
2528#ifdef CONFIG_SCHED_CORE
2529 case PR_SCHED_CORE:
2530 error = sched_core_share_pid(arg2, arg3, arg4, arg5);
2531 break;
2532#endif
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 */