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