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Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
[linux-2.6/btrfs-unstable.git] / kernel / sys.c
blob123bd73046ec6b19324452f0b9563617d7e40630
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 #include "uid16.h"
75
76 #ifndef SET_UNALIGN_CTL
77 # define SET_UNALIGN_CTL(a, b) (-EINVAL)
78 #endif
79 #ifndef GET_UNALIGN_CTL
80 # define GET_UNALIGN_CTL(a, b) (-EINVAL)
81 #endif
82 #ifndef SET_FPEMU_CTL
83 # define SET_FPEMU_CTL(a, b) (-EINVAL)
84 #endif
85 #ifndef GET_FPEMU_CTL
86 # define GET_FPEMU_CTL(a, b) (-EINVAL)
87 #endif
88 #ifndef SET_FPEXC_CTL
89 # define SET_FPEXC_CTL(a, b) (-EINVAL)
90 #endif
91 #ifndef GET_FPEXC_CTL
92 # define GET_FPEXC_CTL(a, b) (-EINVAL)
93 #endif
94 #ifndef GET_ENDIAN
95 # define GET_ENDIAN(a, b) (-EINVAL)
96 #endif
97 #ifndef SET_ENDIAN
98 # define SET_ENDIAN(a, b) (-EINVAL)
99 #endif
100 #ifndef GET_TSC_CTL
101 # define GET_TSC_CTL(a) (-EINVAL)
102 #endif
103 #ifndef SET_TSC_CTL
104 # define SET_TSC_CTL(a) (-EINVAL)
105 #endif
106 #ifndef MPX_ENABLE_MANAGEMENT
107 # define MPX_ENABLE_MANAGEMENT() (-EINVAL)
108 #endif
109 #ifndef MPX_DISABLE_MANAGEMENT
110 # define MPX_DISABLE_MANAGEMENT() (-EINVAL)
111 #endif
112 #ifndef GET_FP_MODE
113 # define GET_FP_MODE(a) (-EINVAL)
114 #endif
115 #ifndef SET_FP_MODE
116 # define SET_FP_MODE(a,b) (-EINVAL)
117 #endif
118 #ifndef SVE_SET_VL
119 # define SVE_SET_VL(a) (-EINVAL)
120 #endif
121 #ifndef SVE_GET_VL
122 # define SVE_GET_VL() (-EINVAL)
123 #endif
124
125 /*
126 * this is where the system-wide overflow UID and GID are defined, for
127 * architectures that now have 32-bit UID/GID but didn't in the past
128 */
129
130 int overflowuid = DEFAULT_OVERFLOWUID;
131 int overflowgid = DEFAULT_OVERFLOWGID;
132
133 EXPORT_SYMBOL(overflowuid);
134 EXPORT_SYMBOL(overflowgid);
135
136 /*
137 * the same as above, but for filesystems which can only store a 16-bit
138 * UID and GID. as such, this is needed on all architectures
139 */
140
141 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
142 int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
143
144 EXPORT_SYMBOL(fs_overflowuid);
145 EXPORT_SYMBOL(fs_overflowgid);
146
147 /*
148 * Returns true if current's euid is same as p's uid or euid,
149 * or has CAP_SYS_NICE to p's user_ns.
150 *
151 * Called with rcu_read_lock, creds are safe
152 */
153 static bool set_one_prio_perm(struct task_struct *p)
154 {
155 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
156
157 if (uid_eq(pcred->uid, cred->euid) ||
158 uid_eq(pcred->euid, cred->euid))
159 return true;
160 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
161 return true;
162 return false;
163 }
164
165 /*
166 * set the priority of a task
167 * - the caller must hold the RCU read lock
168 */
169 static int set_one_prio(struct task_struct *p, int niceval, int error)
170 {
171 int no_nice;
172
173 if (!set_one_prio_perm(p)) {
174 error = -EPERM;
175 goto out;
176 }
177 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
178 error = -EACCES;
179 goto out;
180 }
181 no_nice = security_task_setnice(p, niceval);
182 if (no_nice) {
183 error = no_nice;
184 goto out;
185 }
186 if (error == -ESRCH)
187 error = 0;
188 set_user_nice(p, niceval);
189 out:
190 return error;
191 }
192
193 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
194 {
195 struct task_struct *g, *p;
196 struct user_struct *user;
197 const struct cred *cred = current_cred();
198 int error = -EINVAL;
199 struct pid *pgrp;
200 kuid_t uid;
201
202 if (which > PRIO_USER || which < PRIO_PROCESS)
203 goto out;
204
205 /* normalize: avoid signed division (rounding problems) */
206 error = -ESRCH;
207 if (niceval < MIN_NICE)
208 niceval = MIN_NICE;
209 if (niceval > MAX_NICE)
210 niceval = MAX_NICE;
211
212 rcu_read_lock();
213 read_lock(&tasklist_lock);
214 switch (which) {
215 case PRIO_PROCESS:
216 if (who)
217 p = find_task_by_vpid(who);
218 else
219 p = current;
220 if (p)
221 error = set_one_prio(p, niceval, error);
222 break;
223 case PRIO_PGRP:
224 if (who)
225 pgrp = find_vpid(who);
226 else
227 pgrp = task_pgrp(current);
228 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
229 error = set_one_prio(p, niceval, error);
230 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
231 break;
232 case PRIO_USER:
233 uid = make_kuid(cred->user_ns, who);
234 user = cred->user;
235 if (!who)
236 uid = cred->uid;
237 else if (!uid_eq(uid, cred->uid)) {
238 user = find_user(uid);
239 if (!user)
240 goto out_unlock; /* No processes for this user */
241 }
242 do_each_thread(g, p) {
243 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
244 error = set_one_prio(p, niceval, error);
245 } while_each_thread(g, p);
246 if (!uid_eq(uid, cred->uid))
247 free_uid(user); /* For find_user() */
248 break;
249 }
250 out_unlock:
251 read_unlock(&tasklist_lock);
252 rcu_read_unlock();
253 out:
254 return error;
255 }
256
257 /*
258 * Ugh. To avoid negative return values, "getpriority()" will
259 * not return the normal nice-value, but a negated value that
260 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
261 * to stay compatible.
262 */
263 SYSCALL_DEFINE2(getpriority, int, which, int, who)
264 {
265 struct task_struct *g, *p;
266 struct user_struct *user;
267 const struct cred *cred = current_cred();
268 long niceval, retval = -ESRCH;
269 struct pid *pgrp;
270 kuid_t uid;
271
272 if (which > PRIO_USER || which < PRIO_PROCESS)
273 return -EINVAL;
274
275 rcu_read_lock();
276 read_lock(&tasklist_lock);
277 switch (which) {
278 case PRIO_PROCESS:
279 if (who)
280 p = find_task_by_vpid(who);
281 else
282 p = current;
283 if (p) {
284 niceval = nice_to_rlimit(task_nice(p));
285 if (niceval > retval)
286 retval = niceval;
287 }
288 break;
289 case PRIO_PGRP:
290 if (who)
291 pgrp = find_vpid(who);
292 else
293 pgrp = task_pgrp(current);
294 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
295 niceval = nice_to_rlimit(task_nice(p));
296 if (niceval > retval)
297 retval = niceval;
298 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
299 break;
300 case PRIO_USER:
301 uid = make_kuid(cred->user_ns, who);
302 user = cred->user;
303 if (!who)
304 uid = cred->uid;
305 else if (!uid_eq(uid, cred->uid)) {
306 user = find_user(uid);
307 if (!user)
308 goto out_unlock; /* No processes for this user */
309 }
310 do_each_thread(g, p) {
311 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
312 niceval = nice_to_rlimit(task_nice(p));
313 if (niceval > retval)
314 retval = niceval;
315 }
316 } while_each_thread(g, p);
317 if (!uid_eq(uid, cred->uid))
318 free_uid(user); /* for find_user() */
319 break;
320 }
321 out_unlock:
322 read_unlock(&tasklist_lock);
323 rcu_read_unlock();
324
325 return retval;
326 }
327
328 /*
329 * Unprivileged users may change the real gid to the effective gid
330 * or vice versa. (BSD-style)
331 *
332 * If you set the real gid at all, or set the effective gid to a value not
333 * equal to the real gid, then the saved gid is set to the new effective gid.
334 *
335 * This makes it possible for a setgid program to completely drop its
336 * privileges, which is often a useful assertion to make when you are doing
337 * a security audit over a program.
338 *
339 * The general idea is that a program which uses just setregid() will be
340 * 100% compatible with BSD. A program which uses just setgid() will be
341 * 100% compatible with POSIX with saved IDs.
342 *
343 * SMP: There are not races, the GIDs are checked only by filesystem
344 * operations (as far as semantic preservation is concerned).
345 */
346 #ifdef CONFIG_MULTIUSER
347 long __sys_setregid(gid_t rgid, gid_t egid)
348 {
349 struct user_namespace *ns = current_user_ns();
350 const struct cred *old;
351 struct cred *new;
352 int retval;
353 kgid_t krgid, kegid;
354
355 krgid = make_kgid(ns, rgid);
356 kegid = make_kgid(ns, egid);
357
358 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
359 return -EINVAL;
360 if ((egid != (gid_t) -1) && !gid_valid(kegid))
361 return -EINVAL;
362
363 new = prepare_creds();
364 if (!new)
365 return -ENOMEM;
366 old = current_cred();
367
368 retval = -EPERM;
369 if (rgid != (gid_t) -1) {
370 if (gid_eq(old->gid, krgid) ||
371 gid_eq(old->egid, krgid) ||
372 ns_capable(old->user_ns, CAP_SETGID))
373 new->gid = krgid;
374 else
375 goto error;
376 }
377 if (egid != (gid_t) -1) {
378 if (gid_eq(old->gid, kegid) ||
379 gid_eq(old->egid, kegid) ||
380 gid_eq(old->sgid, kegid) ||
381 ns_capable(old->user_ns, CAP_SETGID))
382 new->egid = kegid;
383 else
384 goto error;
385 }
386
387 if (rgid != (gid_t) -1 ||
388 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
389 new->sgid = new->egid;
390 new->fsgid = new->egid;
391
392 return commit_creds(new);
393
394 error:
395 abort_creds(new);
396 return retval;
397 }
398
399 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
400 {
401 return __sys_setregid(rgid, egid);
402 }
403
404 /*
405 * setgid() is implemented like SysV w/ SAVED_IDS
406 *
407 * SMP: Same implicit races as above.
408 */
409 long __sys_setgid(gid_t gid)
410 {
411 struct user_namespace *ns = current_user_ns();
412 const struct cred *old;
413 struct cred *new;
414 int retval;
415 kgid_t kgid;
416
417 kgid = make_kgid(ns, gid);
418 if (!gid_valid(kgid))
419 return -EINVAL;
420
421 new = prepare_creds();
422 if (!new)
423 return -ENOMEM;
424 old = current_cred();
425
426 retval = -EPERM;
427 if (ns_capable(old->user_ns, CAP_SETGID))
428 new->gid = new->egid = new->sgid = new->fsgid = kgid;
429 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
430 new->egid = new->fsgid = kgid;
431 else
432 goto error;
433
434 return commit_creds(new);
435
436 error:
437 abort_creds(new);
438 return retval;
439 }
440
441 SYSCALL_DEFINE1(setgid, gid_t, gid)
442 {
443 return __sys_setgid(gid);
444 }
445
446 /*
447 * change the user struct in a credentials set to match the new UID
448 */
449 static int set_user(struct cred *new)
450 {
451 struct user_struct *new_user;
452
453 new_user = alloc_uid(new->uid);
454 if (!new_user)
455 return -EAGAIN;
456
457 /*
458 * We don't fail in case of NPROC limit excess here because too many
459 * poorly written programs don't check set*uid() return code, assuming
460 * it never fails if called by root. We may still enforce NPROC limit
461 * for programs doing set*uid()+execve() by harmlessly deferring the
462 * failure to the execve() stage.
463 */
464 if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
465 new_user != INIT_USER)
466 current->flags |= PF_NPROC_EXCEEDED;
467 else
468 current->flags &= ~PF_NPROC_EXCEEDED;
469
470 free_uid(new->user);
471 new->user = new_user;
472 return 0;
473 }
474
475 /*
476 * Unprivileged users may change the real uid to the effective uid
477 * or vice versa. (BSD-style)
478 *
479 * If you set the real uid at all, or set the effective uid to a value not
480 * equal to the real uid, then the saved uid is set to the new effective uid.
481 *
482 * This makes it possible for a setuid program to completely drop its
483 * privileges, which is often a useful assertion to make when you are doing
484 * a security audit over a program.
485 *
486 * The general idea is that a program which uses just setreuid() will be
487 * 100% compatible with BSD. A program which uses just setuid() will be
488 * 100% compatible with POSIX with saved IDs.
489 */
490 long __sys_setreuid(uid_t ruid, uid_t euid)
491 {
492 struct user_namespace *ns = current_user_ns();
493 const struct cred *old;
494 struct cred *new;
495 int retval;
496 kuid_t kruid, keuid;
497
498 kruid = make_kuid(ns, ruid);
499 keuid = make_kuid(ns, euid);
500
501 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
502 return -EINVAL;
503 if ((euid != (uid_t) -1) && !uid_valid(keuid))
504 return -EINVAL;
505
506 new = prepare_creds();
507 if (!new)
508 return -ENOMEM;
509 old = current_cred();
510
511 retval = -EPERM;
512 if (ruid != (uid_t) -1) {
513 new->uid = kruid;
514 if (!uid_eq(old->uid, kruid) &&
515 !uid_eq(old->euid, kruid) &&
516 !ns_capable(old->user_ns, CAP_SETUID))
517 goto error;
518 }
519
520 if (euid != (uid_t) -1) {
521 new->euid = keuid;
522 if (!uid_eq(old->uid, keuid) &&
523 !uid_eq(old->euid, keuid) &&
524 !uid_eq(old->suid, keuid) &&
525 !ns_capable(old->user_ns, CAP_SETUID))
526 goto error;
527 }
528
529 if (!uid_eq(new->uid, old->uid)) {
530 retval = set_user(new);
531 if (retval < 0)
532 goto error;
533 }
534 if (ruid != (uid_t) -1 ||
535 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
536 new->suid = new->euid;
537 new->fsuid = new->euid;
538
539 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
540 if (retval < 0)
541 goto error;
542
543 return commit_creds(new);
544
545 error:
546 abort_creds(new);
547 return retval;
548 }
549
550 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
551 {
552 return __sys_setreuid(ruid, euid);
553 }
554
555 /*
556 * setuid() is implemented like SysV with SAVED_IDS
557 *
558 * Note that SAVED_ID's is deficient in that a setuid root program
559 * like sendmail, for example, cannot set its uid to be a normal
560 * user and then switch back, because if you're root, setuid() sets
561 * the saved uid too. If you don't like this, blame the bright people
562 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
563 * will allow a root program to temporarily drop privileges and be able to
564 * regain them by swapping the real and effective uid.
565 */
566 long __sys_setuid(uid_t uid)
567 {
568 struct user_namespace *ns = current_user_ns();
569 const struct cred *old;
570 struct cred *new;
571 int retval;
572 kuid_t kuid;
573
574 kuid = make_kuid(ns, uid);
575 if (!uid_valid(kuid))
576 return -EINVAL;
577
578 new = prepare_creds();
579 if (!new)
580 return -ENOMEM;
581 old = current_cred();
582
583 retval = -EPERM;
584 if (ns_capable(old->user_ns, CAP_SETUID)) {
585 new->suid = new->uid = kuid;
586 if (!uid_eq(kuid, old->uid)) {
587 retval = set_user(new);
588 if (retval < 0)
589 goto error;
590 }
591 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
592 goto error;
593 }
594
595 new->fsuid = new->euid = kuid;
596
597 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
598 if (retval < 0)
599 goto error;
600
601 return commit_creds(new);
602
603 error:
604 abort_creds(new);
605 return retval;
606 }
607
608 SYSCALL_DEFINE1(setuid, uid_t, uid)
609 {
610 return __sys_setuid(uid);
611 }
612
613
614 /*
615 * This function implements a generic ability to update ruid, euid,
616 * and suid. This allows you to implement the 4.4 compatible seteuid().
617 */
618 long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
619 {
620 struct user_namespace *ns = current_user_ns();
621 const struct cred *old;
622 struct cred *new;
623 int retval;
624 kuid_t kruid, keuid, ksuid;
625
626 kruid = make_kuid(ns, ruid);
627 keuid = make_kuid(ns, euid);
628 ksuid = make_kuid(ns, suid);
629
630 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
631 return -EINVAL;
632
633 if ((euid != (uid_t) -1) && !uid_valid(keuid))
634 return -EINVAL;
635
636 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
637 return -EINVAL;
638
639 new = prepare_creds();
640 if (!new)
641 return -ENOMEM;
642
643 old = current_cred();
644
645 retval = -EPERM;
646 if (!ns_capable(old->user_ns, CAP_SETUID)) {
647 if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
648 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid))
649 goto error;
650 if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
651 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid))
652 goto error;
653 if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
654 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid))
655 goto error;
656 }
657
658 if (ruid != (uid_t) -1) {
659 new->uid = kruid;
660 if (!uid_eq(kruid, old->uid)) {
661 retval = set_user(new);
662 if (retval < 0)
663 goto error;
664 }
665 }
666 if (euid != (uid_t) -1)
667 new->euid = keuid;
668 if (suid != (uid_t) -1)
669 new->suid = ksuid;
670 new->fsuid = new->euid;
671
672 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
673 if (retval < 0)
674 goto error;
675
676 return commit_creds(new);
677
678 error:
679 abort_creds(new);
680 return retval;
681 }
682
683 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
684 {
685 return __sys_setresuid(ruid, euid, suid);
686 }
687
688 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
689 {
690 const struct cred *cred = current_cred();
691 int retval;
692 uid_t ruid, euid, suid;
693
694 ruid = from_kuid_munged(cred->user_ns, cred->uid);
695 euid = from_kuid_munged(cred->user_ns, cred->euid);
696 suid = from_kuid_munged(cred->user_ns, cred->suid);
697
698 retval = put_user(ruid, ruidp);
699 if (!retval) {
700 retval = put_user(euid, euidp);
701 if (!retval)
702 return put_user(suid, suidp);
703 }
704 return retval;
705 }
706
707 /*
708 * Same as above, but for rgid, egid, sgid.
709 */
710 long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
711 {
712 struct user_namespace *ns = current_user_ns();
713 const struct cred *old;
714 struct cred *new;
715 int retval;
716 kgid_t krgid, kegid, ksgid;
717
718 krgid = make_kgid(ns, rgid);
719 kegid = make_kgid(ns, egid);
720 ksgid = make_kgid(ns, sgid);
721
722 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
723 return -EINVAL;
724 if ((egid != (gid_t) -1) && !gid_valid(kegid))
725 return -EINVAL;
726 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
727 return -EINVAL;
728
729 new = prepare_creds();
730 if (!new)
731 return -ENOMEM;
732 old = current_cred();
733
734 retval = -EPERM;
735 if (!ns_capable(old->user_ns, CAP_SETGID)) {
736 if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
737 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid))
738 goto error;
739 if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
740 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid))
741 goto error;
742 if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
743 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid))
744 goto error;
745 }
746
747 if (rgid != (gid_t) -1)
748 new->gid = krgid;
749 if (egid != (gid_t) -1)
750 new->egid = kegid;
751 if (sgid != (gid_t) -1)
752 new->sgid = ksgid;
753 new->fsgid = new->egid;
754
755 return commit_creds(new);
756
757 error:
758 abort_creds(new);
759 return retval;
760 }
761
762 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
763 {
764 return __sys_setresgid(rgid, egid, sgid);
765 }
766
767 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
768 {
769 const struct cred *cred = current_cred();
770 int retval;
771 gid_t rgid, egid, sgid;
772
773 rgid = from_kgid_munged(cred->user_ns, cred->gid);
774 egid = from_kgid_munged(cred->user_ns, cred->egid);
775 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
776
777 retval = put_user(rgid, rgidp);
778 if (!retval) {
779 retval = put_user(egid, egidp);
780 if (!retval)
781 retval = put_user(sgid, sgidp);
782 }
783
784 return retval;
785 }
786
787
788 /*
789 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
790 * is used for "access()" and for the NFS daemon (letting nfsd stay at
791 * whatever uid it wants to). It normally shadows "euid", except when
792 * explicitly set by setfsuid() or for access..
793 */
794 long __sys_setfsuid(uid_t uid)
795 {
796 const struct cred *old;
797 struct cred *new;
798 uid_t old_fsuid;
799 kuid_t kuid;
800
801 old = current_cred();
802 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
803
804 kuid = make_kuid(old->user_ns, uid);
805 if (!uid_valid(kuid))
806 return old_fsuid;
807
808 new = prepare_creds();
809 if (!new)
810 return old_fsuid;
811
812 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
813 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
814 ns_capable(old->user_ns, CAP_SETUID)) {
815 if (!uid_eq(kuid, old->fsuid)) {
816 new->fsuid = kuid;
817 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
818 goto change_okay;
819 }
820 }
821
822 abort_creds(new);
823 return old_fsuid;
824
825 change_okay:
826 commit_creds(new);
827 return old_fsuid;
828 }
829
830 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
831 {
832 return __sys_setfsuid(uid);
833 }
834
835 /*
836 * Samma på svenska..
837 */
838 long __sys_setfsgid(gid_t gid)
839 {
840 const struct cred *old;
841 struct cred *new;
842 gid_t old_fsgid;
843 kgid_t kgid;
844
845 old = current_cred();
846 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
847
848 kgid = make_kgid(old->user_ns, gid);
849 if (!gid_valid(kgid))
850 return old_fsgid;
851
852 new = prepare_creds();
853 if (!new)
854 return old_fsgid;
855
856 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
857 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
858 ns_capable(old->user_ns, CAP_SETGID)) {
859 if (!gid_eq(kgid, old->fsgid)) {
860 new->fsgid = kgid;
861 goto change_okay;
862 }
863 }
864
865 abort_creds(new);
866 return old_fsgid;
867
868 change_okay:
869 commit_creds(new);
870 return old_fsgid;
871 }
872
873 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
874 {
875 return __sys_setfsgid(gid);
876 }
877 #endif /* CONFIG_MULTIUSER */
878
879 /**
880 * sys_getpid - return the thread group id of the current process
881 *
882 * Note, despite the name, this returns the tgid not the pid. The tgid and
883 * the pid are identical unless CLONE_THREAD was specified on clone() in
884 * which case the tgid is the same in all threads of the same group.
885 *
886 * This is SMP safe as current->tgid does not change.
887 */
888 SYSCALL_DEFINE0(getpid)
889 {
890 return task_tgid_vnr(current);
891 }
892
893 /* Thread ID - the internal kernel "pid" */
894 SYSCALL_DEFINE0(gettid)
895 {
896 return task_pid_vnr(current);
897 }
898
899 /*
900 * Accessing ->real_parent is not SMP-safe, it could
901 * change from under us. However, we can use a stale
902 * value of ->real_parent under rcu_read_lock(), see
903 * release_task()->call_rcu(delayed_put_task_struct).
904 */
905 SYSCALL_DEFINE0(getppid)
906 {
907 int pid;
908
909 rcu_read_lock();
910 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
911 rcu_read_unlock();
912
913 return pid;
914 }
915
916 SYSCALL_DEFINE0(getuid)
917 {
918 /* Only we change this so SMP safe */
919 return from_kuid_munged(current_user_ns(), current_uid());
920 }
921
922 SYSCALL_DEFINE0(geteuid)
923 {
924 /* Only we change this so SMP safe */
925 return from_kuid_munged(current_user_ns(), current_euid());
926 }
927
928 SYSCALL_DEFINE0(getgid)
929 {
930 /* Only we change this so SMP safe */
931 return from_kgid_munged(current_user_ns(), current_gid());
932 }
933
934 SYSCALL_DEFINE0(getegid)
935 {
936 /* Only we change this so SMP safe */
937 return from_kgid_munged(current_user_ns(), current_egid());
938 }
939
940 static void do_sys_times(struct tms *tms)
941 {
942 u64 tgutime, tgstime, cutime, cstime;
943
944 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
945 cutime = current->signal->cutime;
946 cstime = current->signal->cstime;
947 tms->tms_utime = nsec_to_clock_t(tgutime);
948 tms->tms_stime = nsec_to_clock_t(tgstime);
949 tms->tms_cutime = nsec_to_clock_t(cutime);
950 tms->tms_cstime = nsec_to_clock_t(cstime);
951 }
952
953 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
954 {
955 if (tbuf) {
956 struct tms tmp;
957
958 do_sys_times(&tmp);
959 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
960 return -EFAULT;
961 }
962 force_successful_syscall_return();
963 return (long) jiffies_64_to_clock_t(get_jiffies_64());
964 }
965
966 #ifdef CONFIG_COMPAT
967 static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
968 {
969 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
970 }
971
972 COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
973 {
974 if (tbuf) {
975 struct tms tms;
976 struct compat_tms tmp;
977
978 do_sys_times(&tms);
979 /* Convert our struct tms to the compat version. */
980 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
981 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
982 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
983 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
984 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
985 return -EFAULT;
986 }
987 force_successful_syscall_return();
988 return compat_jiffies_to_clock_t(jiffies);
989 }
990 #endif
991
992 /*
993 * This needs some heavy checking ...
994 * I just haven't the stomach for it. I also don't fully
995 * understand sessions/pgrp etc. Let somebody who does explain it.
996 *
997 * OK, I think I have the protection semantics right.... this is really
998 * only important on a multi-user system anyway, to make sure one user
999 * can't send a signal to a process owned by another. -TYT, 12/12/91
1000 *
1001 * !PF_FORKNOEXEC check to conform completely to POSIX.
1002 */
1003 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1004 {
1005 struct task_struct *p;
1006 struct task_struct *group_leader = current->group_leader;
1007 struct pid *pgrp;
1008 int err;
1009
1010 if (!pid)
1011 pid = task_pid_vnr(group_leader);
1012 if (!pgid)
1013 pgid = pid;
1014 if (pgid < 0)
1015 return -EINVAL;
1016 rcu_read_lock();
1017
1018 /* From this point forward we keep holding onto the tasklist lock
1019 * so that our parent does not change from under us. -DaveM
1020 */
1021 write_lock_irq(&tasklist_lock);
1022
1023 err = -ESRCH;
1024 p = find_task_by_vpid(pid);
1025 if (!p)
1026 goto out;
1027
1028 err = -EINVAL;
1029 if (!thread_group_leader(p))
1030 goto out;
1031
1032 if (same_thread_group(p->real_parent, group_leader)) {
1033 err = -EPERM;
1034 if (task_session(p) != task_session(group_leader))
1035 goto out;
1036 err = -EACCES;
1037 if (!(p->flags & PF_FORKNOEXEC))
1038 goto out;
1039 } else {
1040 err = -ESRCH;
1041 if (p != group_leader)
1042 goto out;
1043 }
1044
1045 err = -EPERM;
1046 if (p->signal->leader)
1047 goto out;
1048
1049 pgrp = task_pid(p);
1050 if (pgid != pid) {
1051 struct task_struct *g;
1052
1053 pgrp = find_vpid(pgid);
1054 g = pid_task(pgrp, PIDTYPE_PGID);
1055 if (!g || task_session(g) != task_session(group_leader))
1056 goto out;
1057 }
1058
1059 err = security_task_setpgid(p, pgid);
1060 if (err)
1061 goto out;
1062
1063 if (task_pgrp(p) != pgrp)
1064 change_pid(p, PIDTYPE_PGID, pgrp);
1065
1066 err = 0;
1067 out:
1068 /* All paths lead to here, thus we are safe. -DaveM */
1069 write_unlock_irq(&tasklist_lock);
1070 rcu_read_unlock();
1071 return err;
1072 }
1073
1074 static int do_getpgid(pid_t pid)
1075 {
1076 struct task_struct *p;
1077 struct pid *grp;
1078 int retval;
1079
1080 rcu_read_lock();
1081 if (!pid)
1082 grp = task_pgrp(current);
1083 else {
1084 retval = -ESRCH;
1085 p = find_task_by_vpid(pid);
1086 if (!p)
1087 goto out;
1088 grp = task_pgrp(p);
1089 if (!grp)
1090 goto out;
1091
1092 retval = security_task_getpgid(p);
1093 if (retval)
1094 goto out;
1095 }
1096 retval = pid_vnr(grp);
1097 out:
1098 rcu_read_unlock();
1099 return retval;
1100 }
1101
1102 SYSCALL_DEFINE1(getpgid, pid_t, pid)
1103 {
1104 return do_getpgid(pid);
1105 }
1106
1107 #ifdef __ARCH_WANT_SYS_GETPGRP
1108
1109 SYSCALL_DEFINE0(getpgrp)
1110 {
1111 return do_getpgid(0);
1112 }
1113
1114 #endif
1115
1116 SYSCALL_DEFINE1(getsid, pid_t, pid)
1117 {
1118 struct task_struct *p;
1119 struct pid *sid;
1120 int retval;
1121
1122 rcu_read_lock();
1123 if (!pid)
1124 sid = task_session(current);
1125 else {
1126 retval = -ESRCH;
1127 p = find_task_by_vpid(pid);
1128 if (!p)
1129 goto out;
1130 sid = task_session(p);
1131 if (!sid)
1132 goto out;
1133
1134 retval = security_task_getsid(p);
1135 if (retval)
1136 goto out;
1137 }
1138 retval = pid_vnr(sid);
1139 out:
1140 rcu_read_unlock();
1141 return retval;
1142 }
1143
1144 static void set_special_pids(struct pid *pid)
1145 {
1146 struct task_struct *curr = current->group_leader;
1147
1148 if (task_session(curr) != pid)
1149 change_pid(curr, PIDTYPE_SID, pid);
1150
1151 if (task_pgrp(curr) != pid)
1152 change_pid(curr, PIDTYPE_PGID, pid);
1153 }
1154
1155 int ksys_setsid(void)
1156 {
1157 struct task_struct *group_leader = current->group_leader;
1158 struct pid *sid = task_pid(group_leader);
1159 pid_t session = pid_vnr(sid);
1160 int err = -EPERM;
1161
1162 write_lock_irq(&tasklist_lock);
1163 /* Fail if I am already a session leader */
1164 if (group_leader->signal->leader)
1165 goto out;
1166
1167 /* Fail if a process group id already exists that equals the
1168 * proposed session id.
1169 */
1170 if (pid_task(sid, PIDTYPE_PGID))
1171 goto out;
1172
1173 group_leader->signal->leader = 1;
1174 set_special_pids(sid);
1175
1176 proc_clear_tty(group_leader);
1177
1178 err = session;
1179 out:
1180 write_unlock_irq(&tasklist_lock);
1181 if (err > 0) {
1182 proc_sid_connector(group_leader);
1183 sched_autogroup_create_attach(group_leader);
1184 }
1185 return err;
1186 }
1187
1188 SYSCALL_DEFINE0(setsid)
1189 {
1190 return ksys_setsid();
1191 }
1192
1193 DECLARE_RWSEM(uts_sem);
1194
1195 #ifdef COMPAT_UTS_MACHINE
1196 #define override_architecture(name) \
1197 (personality(current->personality) == PER_LINUX32 && \
1198 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1199 sizeof(COMPAT_UTS_MACHINE)))
1200 #else
1201 #define override_architecture(name) 0
1202 #endif
1203
1204 /*
1205 * Work around broken programs that cannot handle "Linux 3.0".
1206 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1207 * And we map 4.x to 2.6.60+x, so 4.0 would be 2.6.60.
1208 */
1209 static int override_release(char __user *release, size_t len)
1210 {
1211 int ret = 0;
1212
1213 if (current->personality & UNAME26) {
1214 const char *rest = UTS_RELEASE;
1215 char buf[65] = { 0 };
1216 int ndots = 0;
1217 unsigned v;
1218 size_t copy;
1219
1220 while (*rest) {
1221 if (*rest == '.' && ++ndots >= 3)
1222 break;
1223 if (!isdigit(*rest) && *rest != '.')
1224 break;
1225 rest++;
1226 }
1227 v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 60;
1228 copy = clamp_t(size_t, len, 1, sizeof(buf));
1229 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1230 ret = copy_to_user(release, buf, copy + 1);
1231 }
1232 return ret;
1233 }
1234
1235 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1236 {
1237 struct new_utsname tmp;
1238
1239 down_read(&uts_sem);
1240 memcpy(&tmp, utsname(), sizeof(tmp));
1241 up_read(&uts_sem);
1242 if (copy_to_user(name, &tmp, sizeof(tmp)))
1243 return -EFAULT;
1244
1245 if (override_release(name->release, sizeof(name->release)))
1246 return -EFAULT;
1247 if (override_architecture(name))
1248 return -EFAULT;
1249 return 0;
1250 }
1251
1252 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1253 /*
1254 * Old cruft
1255 */
1256 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1257 {
1258 struct old_utsname tmp;
1259
1260 if (!name)
1261 return -EFAULT;
1262
1263 down_read(&uts_sem);
1264 memcpy(&tmp, utsname(), sizeof(tmp));
1265 up_read(&uts_sem);
1266 if (copy_to_user(name, &tmp, sizeof(tmp)))
1267 return -EFAULT;
1268
1269 if (override_release(name->release, sizeof(name->release)))
1270 return -EFAULT;
1271 if (override_architecture(name))
1272 return -EFAULT;
1273 return 0;
1274 }
1275
1276 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1277 {
1278 struct oldold_utsname tmp = {};
1279
1280 if (!name)
1281 return -EFAULT;
1282
1283 down_read(&uts_sem);
1284 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1285 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1286 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1287 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1288 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
1289 up_read(&uts_sem);
1290 if (copy_to_user(name, &tmp, sizeof(tmp)))
1291 return -EFAULT;
1292
1293 if (override_architecture(name))
1294 return -EFAULT;
1295 if (override_release(name->release, sizeof(name->release)))
1296 return -EFAULT;
1297 return 0;
1298 }
1299 #endif
1300
1301 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1302 {
1303 int errno;
1304 char tmp[__NEW_UTS_LEN];
1305
1306 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1307 return -EPERM;
1308
1309 if (len < 0 || len > __NEW_UTS_LEN)
1310 return -EINVAL;
1311 errno = -EFAULT;
1312 if (!copy_from_user(tmp, name, len)) {
1313 struct new_utsname *u;
1314
1315 down_write(&uts_sem);
1316 u = utsname();
1317 memcpy(u->nodename, tmp, len);
1318 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1319 errno = 0;
1320 uts_proc_notify(UTS_PROC_HOSTNAME);
1321 up_write(&uts_sem);
1322 }
1323 return errno;
1324 }
1325
1326 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1327
1328 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1329 {
1330 int i;
1331 struct new_utsname *u;
1332 char tmp[__NEW_UTS_LEN + 1];
1333
1334 if (len < 0)
1335 return -EINVAL;
1336 down_read(&uts_sem);
1337 u = utsname();
1338 i = 1 + strlen(u->nodename);
1339 if (i > len)
1340 i = len;
1341 memcpy(tmp, u->nodename, i);
1342 up_read(&uts_sem);
1343 if (copy_to_user(name, tmp, i))
1344 return -EFAULT;
1345 return 0;
1346 }
1347
1348 #endif
1349
1350 /*
1351 * Only setdomainname; getdomainname can be implemented by calling
1352 * uname()
1353 */
1354 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1355 {
1356 int errno;
1357 char tmp[__NEW_UTS_LEN];
1358
1359 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1360 return -EPERM;
1361 if (len < 0 || len > __NEW_UTS_LEN)
1362 return -EINVAL;
1363
1364 errno = -EFAULT;
1365 if (!copy_from_user(tmp, name, len)) {
1366 struct new_utsname *u;
1367
1368 down_write(&uts_sem);
1369 u = utsname();
1370 memcpy(u->domainname, tmp, len);
1371 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1372 errno = 0;
1373 uts_proc_notify(UTS_PROC_DOMAINNAME);
1374 up_write(&uts_sem);
1375 }
1376 return errno;
1377 }
1378
1379 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1380 {
1381 struct rlimit value;
1382 int ret;
1383
1384 ret = do_prlimit(current, resource, NULL, &value);
1385 if (!ret)
1386 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1387
1388 return ret;
1389 }
1390
1391 #ifdef CONFIG_COMPAT
1392
1393 COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1394 struct compat_rlimit __user *, rlim)
1395 {
1396 struct rlimit r;
1397 struct compat_rlimit r32;
1398
1399 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1400 return -EFAULT;
1401
1402 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1403 r.rlim_cur = RLIM_INFINITY;
1404 else
1405 r.rlim_cur = r32.rlim_cur;
1406 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1407 r.rlim_max = RLIM_INFINITY;
1408 else
1409 r.rlim_max = r32.rlim_max;
1410 return do_prlimit(current, resource, &r, NULL);
1411 }
1412
1413 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1414 struct compat_rlimit __user *, rlim)
1415 {
1416 struct rlimit r;
1417 int ret;
1418
1419 ret = do_prlimit(current, resource, NULL, &r);
1420 if (!ret) {
1421 struct compat_rlimit r32;
1422 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1423 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1424 else
1425 r32.rlim_cur = r.rlim_cur;
1426 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1427 r32.rlim_max = COMPAT_RLIM_INFINITY;
1428 else
1429 r32.rlim_max = r.rlim_max;
1430
1431 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1432 return -EFAULT;
1433 }
1434 return ret;
1435 }
1436
1437 #endif
1438
1439 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1440
1441 /*
1442 * Back compatibility for getrlimit. Needed for some apps.
1443 */
1444 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1445 struct rlimit __user *, rlim)
1446 {
1447 struct rlimit x;
1448 if (resource >= RLIM_NLIMITS)
1449 return -EINVAL;
1450
1451 resource = array_index_nospec(resource, RLIM_NLIMITS);
1452 task_lock(current->group_leader);
1453 x = current->signal->rlim[resource];
1454 task_unlock(current->group_leader);
1455 if (x.rlim_cur > 0x7FFFFFFF)
1456 x.rlim_cur = 0x7FFFFFFF;
1457 if (x.rlim_max > 0x7FFFFFFF)
1458 x.rlim_max = 0x7FFFFFFF;
1459 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1460 }
1461
1462 #ifdef CONFIG_COMPAT
1463 COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1464 struct compat_rlimit __user *, rlim)
1465 {
1466 struct rlimit r;
1467
1468 if (resource >= RLIM_NLIMITS)
1469 return -EINVAL;
1470
1471 resource = array_index_nospec(resource, RLIM_NLIMITS);
1472 task_lock(current->group_leader);
1473 r = current->signal->rlim[resource];
1474 task_unlock(current->group_leader);
1475 if (r.rlim_cur > 0x7FFFFFFF)
1476 r.rlim_cur = 0x7FFFFFFF;
1477 if (r.rlim_max > 0x7FFFFFFF)
1478 r.rlim_max = 0x7FFFFFFF;
1479
1480 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1481 put_user(r.rlim_max, &rlim->rlim_max))
1482 return -EFAULT;
1483 return 0;
1484 }
1485 #endif
1486
1487 #endif
1488
1489 static inline bool rlim64_is_infinity(__u64 rlim64)
1490 {
1491 #if BITS_PER_LONG < 64
1492 return rlim64 >= ULONG_MAX;
1493 #else
1494 return rlim64 == RLIM64_INFINITY;
1495 #endif
1496 }
1497
1498 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1499 {
1500 if (rlim->rlim_cur == RLIM_INFINITY)
1501 rlim64->rlim_cur = RLIM64_INFINITY;
1502 else
1503 rlim64->rlim_cur = rlim->rlim_cur;
1504 if (rlim->rlim_max == RLIM_INFINITY)
1505 rlim64->rlim_max = RLIM64_INFINITY;
1506 else
1507 rlim64->rlim_max = rlim->rlim_max;
1508 }
1509
1510 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1511 {
1512 if (rlim64_is_infinity(rlim64->rlim_cur))
1513 rlim->rlim_cur = RLIM_INFINITY;
1514 else
1515 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1516 if (rlim64_is_infinity(rlim64->rlim_max))
1517 rlim->rlim_max = RLIM_INFINITY;
1518 else
1519 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1520 }
1521
1522 /* make sure you are allowed to change @tsk limits before calling this */
1523 int do_prlimit(struct task_struct *tsk, unsigned int resource,
1524 struct rlimit *new_rlim, struct rlimit *old_rlim)
1525 {
1526 struct rlimit *rlim;
1527 int retval = 0;
1528
1529 if (resource >= RLIM_NLIMITS)
1530 return -EINVAL;
1531 if (new_rlim) {
1532 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1533 return -EINVAL;
1534 if (resource == RLIMIT_NOFILE &&
1535 new_rlim->rlim_max > sysctl_nr_open)
1536 return -EPERM;
1537 }
1538
1539 /* protect tsk->signal and tsk->sighand from disappearing */
1540 read_lock(&tasklist_lock);
1541 if (!tsk->sighand) {
1542 retval = -ESRCH;
1543 goto out;
1544 }
1545
1546 rlim = tsk->signal->rlim + resource;
1547 task_lock(tsk->group_leader);
1548 if (new_rlim) {
1549 /* Keep the capable check against init_user_ns until
1550 cgroups can contain all limits */
1551 if (new_rlim->rlim_max > rlim->rlim_max &&
1552 !capable(CAP_SYS_RESOURCE))
1553 retval = -EPERM;
1554 if (!retval)
1555 retval = security_task_setrlimit(tsk, resource, new_rlim);
1556 if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) {
1557 /*
1558 * The caller is asking for an immediate RLIMIT_CPU
1559 * expiry. But we use the zero value to mean "it was
1560 * never set". So let's cheat and make it one second
1561 * instead
1562 */
1563 new_rlim->rlim_cur = 1;
1564 }
1565 }
1566 if (!retval) {
1567 if (old_rlim)
1568 *old_rlim = *rlim;
1569 if (new_rlim)
1570 *rlim = *new_rlim;
1571 }
1572 task_unlock(tsk->group_leader);
1573
1574 /*
1575 * RLIMIT_CPU handling. Note that the kernel fails to return an error
1576 * code if it rejected the user's attempt to set RLIMIT_CPU. This is a
1577 * very long-standing error, and fixing it now risks breakage of
1578 * applications, so we live with it
1579 */
1580 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1581 new_rlim->rlim_cur != RLIM_INFINITY &&
1582 IS_ENABLED(CONFIG_POSIX_TIMERS))
1583 update_rlimit_cpu(tsk, new_rlim->rlim_cur);
1584 out:
1585 read_unlock(&tasklist_lock);
1586 return retval;
1587 }
1588
1589 /* rcu lock must be held */
1590 static int check_prlimit_permission(struct task_struct *task,
1591 unsigned int flags)
1592 {
1593 const struct cred *cred = current_cred(), *tcred;
1594 bool id_match;
1595
1596 if (current == task)
1597 return 0;
1598
1599 tcred = __task_cred(task);
1600 id_match = (uid_eq(cred->uid, tcred->euid) &&
1601 uid_eq(cred->uid, tcred->suid) &&
1602 uid_eq(cred->uid, tcred->uid) &&
1603 gid_eq(cred->gid, tcred->egid) &&
1604 gid_eq(cred->gid, tcred->sgid) &&
1605 gid_eq(cred->gid, tcred->gid));
1606 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1607 return -EPERM;
1608
1609 return security_task_prlimit(cred, tcred, flags);
1610 }
1611
1612 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1613 const struct rlimit64 __user *, new_rlim,
1614 struct rlimit64 __user *, old_rlim)
1615 {
1616 struct rlimit64 old64, new64;
1617 struct rlimit old, new;
1618 struct task_struct *tsk;
1619 unsigned int checkflags = 0;
1620 int ret;
1621
1622 if (old_rlim)
1623 checkflags |= LSM_PRLIMIT_READ;
1624
1625 if (new_rlim) {
1626 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1627 return -EFAULT;
1628 rlim64_to_rlim(&new64, &new);
1629 checkflags |= LSM_PRLIMIT_WRITE;
1630 }
1631
1632 rcu_read_lock();
1633 tsk = pid ? find_task_by_vpid(pid) : current;
1634 if (!tsk) {
1635 rcu_read_unlock();
1636 return -ESRCH;
1637 }
1638 ret = check_prlimit_permission(tsk, checkflags);
1639 if (ret) {
1640 rcu_read_unlock();
1641 return ret;
1642 }
1643 get_task_struct(tsk);
1644 rcu_read_unlock();
1645
1646 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1647 old_rlim ? &old : NULL);
1648
1649 if (!ret && old_rlim) {
1650 rlim_to_rlim64(&old, &old64);
1651 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1652 ret = -EFAULT;
1653 }
1654
1655 put_task_struct(tsk);
1656 return ret;
1657 }
1658
1659 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1660 {
1661 struct rlimit new_rlim;
1662
1663 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1664 return -EFAULT;
1665 return do_prlimit(current, resource, &new_rlim, NULL);
1666 }
1667
1668 /*
1669 * It would make sense to put struct rusage in the task_struct,
1670 * except that would make the task_struct be *really big*. After
1671 * task_struct gets moved into malloc'ed memory, it would
1672 * make sense to do this. It will make moving the rest of the information
1673 * a lot simpler! (Which we're not doing right now because we're not
1674 * measuring them yet).
1675 *
1676 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1677 * races with threads incrementing their own counters. But since word
1678 * reads are atomic, we either get new values or old values and we don't
1679 * care which for the sums. We always take the siglock to protect reading
1680 * the c* fields from p->signal from races with exit.c updating those
1681 * fields when reaping, so a sample either gets all the additions of a
1682 * given child after it's reaped, or none so this sample is before reaping.
1683 *
1684 * Locking:
1685 * We need to take the siglock for CHILDEREN, SELF and BOTH
1686 * for the cases current multithreaded, non-current single threaded
1687 * non-current multithreaded. Thread traversal is now safe with
1688 * the siglock held.
1689 * Strictly speaking, we donot need to take the siglock if we are current and
1690 * single threaded, as no one else can take our signal_struct away, no one
1691 * else can reap the children to update signal->c* counters, and no one else
1692 * can race with the signal-> fields. If we do not take any lock, the
1693 * signal-> fields could be read out of order while another thread was just
1694 * exiting. So we should place a read memory barrier when we avoid the lock.
1695 * On the writer side, write memory barrier is implied in __exit_signal
1696 * as __exit_signal releases the siglock spinlock after updating the signal->
1697 * fields. But we don't do this yet to keep things simple.
1698 *
1699 */
1700
1701 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1702 {
1703 r->ru_nvcsw += t->nvcsw;
1704 r->ru_nivcsw += t->nivcsw;
1705 r->ru_minflt += t->min_flt;
1706 r->ru_majflt += t->maj_flt;
1707 r->ru_inblock += task_io_get_inblock(t);
1708 r->ru_oublock += task_io_get_oublock(t);
1709 }
1710
1711 void getrusage(struct task_struct *p, int who, struct rusage *r)
1712 {
1713 struct task_struct *t;
1714 unsigned long flags;
1715 u64 tgutime, tgstime, utime, stime;
1716 unsigned long maxrss = 0;
1717
1718 memset((char *)r, 0, sizeof (*r));
1719 utime = stime = 0;
1720
1721 if (who == RUSAGE_THREAD) {
1722 task_cputime_adjusted(current, &utime, &stime);
1723 accumulate_thread_rusage(p, r);
1724 maxrss = p->signal->maxrss;
1725 goto out;
1726 }
1727
1728 if (!lock_task_sighand(p, &flags))
1729 return;
1730
1731 switch (who) {
1732 case RUSAGE_BOTH:
1733 case RUSAGE_CHILDREN:
1734 utime = p->signal->cutime;
1735 stime = p->signal->cstime;
1736 r->ru_nvcsw = p->signal->cnvcsw;
1737 r->ru_nivcsw = p->signal->cnivcsw;
1738 r->ru_minflt = p->signal->cmin_flt;
1739 r->ru_majflt = p->signal->cmaj_flt;
1740 r->ru_inblock = p->signal->cinblock;
1741 r->ru_oublock = p->signal->coublock;
1742 maxrss = p->signal->cmaxrss;
1743
1744 if (who == RUSAGE_CHILDREN)
1745 break;
1746
1747 case RUSAGE_SELF:
1748 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1749 utime += tgutime;
1750 stime += tgstime;
1751 r->ru_nvcsw += p->signal->nvcsw;
1752 r->ru_nivcsw += p->signal->nivcsw;
1753 r->ru_minflt += p->signal->min_flt;
1754 r->ru_majflt += p->signal->maj_flt;
1755 r->ru_inblock += p->signal->inblock;
1756 r->ru_oublock += p->signal->oublock;
1757 if (maxrss < p->signal->maxrss)
1758 maxrss = p->signal->maxrss;
1759 t = p;
1760 do {
1761 accumulate_thread_rusage(t, r);
1762 } while_each_thread(p, t);
1763 break;
1764
1765 default:
1766 BUG();
1767 }
1768 unlock_task_sighand(p, &flags);
1769
1770 out:
1771 r->ru_utime = ns_to_timeval(utime);
1772 r->ru_stime = ns_to_timeval(stime);
1773
1774 if (who != RUSAGE_CHILDREN) {
1775 struct mm_struct *mm = get_task_mm(p);
1776
1777 if (mm) {
1778 setmax_mm_hiwater_rss(&maxrss, mm);
1779 mmput(mm);
1780 }
1781 }
1782 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1783 }
1784
1785 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1786 {
1787 struct rusage r;
1788
1789 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1790 who != RUSAGE_THREAD)
1791 return -EINVAL;
1792
1793 getrusage(current, who, &r);
1794 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1795 }
1796
1797 #ifdef CONFIG_COMPAT
1798 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1799 {
1800 struct rusage r;
1801
1802 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1803 who != RUSAGE_THREAD)
1804 return -EINVAL;
1805
1806 getrusage(current, who, &r);
1807 return put_compat_rusage(&r, ru);
1808 }
1809 #endif
1810
1811 SYSCALL_DEFINE1(umask, int, mask)
1812 {
1813 mask = xchg(&current->fs->umask, mask & S_IRWXUGO);
1814 return mask;
1815 }
1816
1817 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1818 {
1819 struct fd exe;
1820 struct file *old_exe, *exe_file;
1821 struct inode *inode;
1822 int err;
1823
1824 exe = fdget(fd);
1825 if (!exe.file)
1826 return -EBADF;
1827
1828 inode = file_inode(exe.file);
1829
1830 /*
1831 * Because the original mm->exe_file points to executable file, make
1832 * sure that this one is executable as well, to avoid breaking an
1833 * overall picture.
1834 */
1835 err = -EACCES;
1836 if (!S_ISREG(inode->i_mode) || path_noexec(&exe.file->f_path))
1837 goto exit;
1838
1839 err = inode_permission(inode, MAY_EXEC);
1840 if (err)
1841 goto exit;
1842
1843 /*
1844 * Forbid mm->exe_file change if old file still mapped.
1845 */
1846 exe_file = get_mm_exe_file(mm);
1847 err = -EBUSY;
1848 if (exe_file) {
1849 struct vm_area_struct *vma;
1850
1851 down_read(&mm->mmap_sem);
1852 for (vma = mm->mmap; vma; vma = vma->vm_next) {
1853 if (!vma->vm_file)
1854 continue;
1855 if (path_equal(&vma->vm_file->f_path,
1856 &exe_file->f_path))
1857 goto exit_err;
1858 }
1859
1860 up_read(&mm->mmap_sem);
1861 fput(exe_file);
1862 }
1863
1864 err = 0;
1865 /* set the new file, lockless */
1866 get_file(exe.file);
1867 old_exe = xchg(&mm->exe_file, exe.file);
1868 if (old_exe)
1869 fput(old_exe);
1870 exit:
1871 fdput(exe);
1872 return err;
1873 exit_err:
1874 up_read(&mm->mmap_sem);
1875 fput(exe_file);
1876 goto exit;
1877 }
1878
1879 /*
1880 * WARNING: we don't require any capability here so be very careful
1881 * in what is allowed for modification from userspace.
1882 */
1883 static int validate_prctl_map(struct prctl_mm_map *prctl_map)
1884 {
1885 unsigned long mmap_max_addr = TASK_SIZE;
1886 struct mm_struct *mm = current->mm;
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 * @brk should be after @end_data in traditional maps.
1934 */
1935 if (prctl_map->start_brk <= prctl_map->end_data ||
1936 prctl_map->brk <= prctl_map->end_data)
1937 goto out;
1938
1939 /*
1940 * Neither we should allow to override limits if they set.
1941 */
1942 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1943 prctl_map->start_brk, prctl_map->end_data,
1944 prctl_map->start_data))
1945 goto out;
1946
1947 /*
1948 * Someone is trying to cheat the auxv vector.
1949 */
1950 if (prctl_map->auxv_size) {
1951 if (!prctl_map->auxv || prctl_map->auxv_size > sizeof(mm->saved_auxv))
1952 goto out;
1953 }
1954
1955 /*
1956 * Finally, make sure the caller has the rights to
1957 * change /proc/pid/exe link: only local sys admin should
1958 * be allowed to.
1959 */
1960 if (prctl_map->exe_fd != (u32)-1) {
1961 if (!ns_capable(current_user_ns(), CAP_SYS_ADMIN))
1962 goto out;
1963 }
1964
1965 error = 0;
1966 out:
1967 return error;
1968 }
1969
1970 #ifdef CONFIG_CHECKPOINT_RESTORE
1971 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
1972 {
1973 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
1974 unsigned long user_auxv[AT_VECTOR_SIZE];
1975 struct mm_struct *mm = current->mm;
1976 int error;
1977
1978 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
1979 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
1980
1981 if (opt == PR_SET_MM_MAP_SIZE)
1982 return put_user((unsigned int)sizeof(prctl_map),
1983 (unsigned int __user *)addr);
1984
1985 if (data_size != sizeof(prctl_map))
1986 return -EINVAL;
1987
1988 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
1989 return -EFAULT;
1990
1991 error = validate_prctl_map(&prctl_map);
1992 if (error)
1993 return error;
1994
1995 if (prctl_map.auxv_size) {
1996 memset(user_auxv, 0, sizeof(user_auxv));
1997 if (copy_from_user(user_auxv,
1998 (const void __user *)prctl_map.auxv,
1999 prctl_map.auxv_size))
2000 return -EFAULT;
2001
2002 /* Last entry must be AT_NULL as specification requires */
2003 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
2004 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
2005 }
2006
2007 if (prctl_map.exe_fd != (u32)-1) {
2008 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
2009 if (error)
2010 return error;
2011 }
2012
2013 /*
2014 * arg_lock protects concurent updates but we still need mmap_sem for
2015 * read to exclude races with sys_brk.
2016 */
2017 down_read(&mm->mmap_sem);
2018
2019 /*
2020 * We don't validate if these members are pointing to
2021 * real present VMAs because application may have correspond
2022 * VMAs already unmapped and kernel uses these members for statistics
2023 * output in procfs mostly, except
2024 *
2025 * - @start_brk/@brk which are used in do_brk but kernel lookups
2026 * for VMAs when updating these memvers so anything wrong written
2027 * here cause kernel to swear at userspace program but won't lead
2028 * to any problem in kernel itself
2029 */
2030
2031 spin_lock(&mm->arg_lock);
2032 mm->start_code = prctl_map.start_code;
2033 mm->end_code = prctl_map.end_code;
2034 mm->start_data = prctl_map.start_data;
2035 mm->end_data = prctl_map.end_data;
2036 mm->start_brk = prctl_map.start_brk;
2037 mm->brk = prctl_map.brk;
2038 mm->start_stack = prctl_map.start_stack;
2039 mm->arg_start = prctl_map.arg_start;
2040 mm->arg_end = prctl_map.arg_end;
2041 mm->env_start = prctl_map.env_start;
2042 mm->env_end = prctl_map.env_end;
2043 spin_unlock(&mm->arg_lock);
2044
2045 /*
2046 * Note this update of @saved_auxv is lockless thus
2047 * if someone reads this member in procfs while we're
2048 * updating -- it may get partly updated results. It's
2049 * known and acceptable trade off: we leave it as is to
2050 * not introduce additional locks here making the kernel
2051 * more complex.
2052 */
2053 if (prctl_map.auxv_size)
2054 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2055
2056 up_read(&mm->mmap_sem);
2057 return 0;
2058 }
2059 #endif /* CONFIG_CHECKPOINT_RESTORE */
2060
2061 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2062 unsigned long len)
2063 {
2064 /*
2065 * This doesn't move the auxiliary vector itself since it's pinned to
2066 * mm_struct, but it permits filling the vector with new values. It's
2067 * up to the caller to provide sane values here, otherwise userspace
2068 * tools which use this vector might be unhappy.
2069 */
2070 unsigned long user_auxv[AT_VECTOR_SIZE];
2071
2072 if (len > sizeof(user_auxv))
2073 return -EINVAL;
2074
2075 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2076 return -EFAULT;
2077
2078 /* Make sure the last entry is always AT_NULL */
2079 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2080 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2081
2082 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2083
2084 task_lock(current);
2085 memcpy(mm->saved_auxv, user_auxv, len);
2086 task_unlock(current);
2087
2088 return 0;
2089 }
2090
2091 static int prctl_set_mm(int opt, unsigned long addr,
2092 unsigned long arg4, unsigned long arg5)
2093 {
2094 struct mm_struct *mm = current->mm;
2095 struct prctl_mm_map prctl_map;
2096 struct vm_area_struct *vma;
2097 int error;
2098
2099 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2100 opt != PR_SET_MM_MAP &&
2101 opt != PR_SET_MM_MAP_SIZE)))
2102 return -EINVAL;
2103
2104 #ifdef CONFIG_CHECKPOINT_RESTORE
2105 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2106 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2107 #endif
2108
2109 if (!capable(CAP_SYS_RESOURCE))
2110 return -EPERM;
2111
2112 if (opt == PR_SET_MM_EXE_FILE)
2113 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
2114
2115 if (opt == PR_SET_MM_AUXV)
2116 return prctl_set_auxv(mm, addr, arg4);
2117
2118 if (addr >= TASK_SIZE || addr < mmap_min_addr)
2119 return -EINVAL;
2120
2121 error = -EINVAL;
2122
2123 down_write(&mm->mmap_sem);
2124 vma = find_vma(mm, addr);
2125
2126 prctl_map.start_code = mm->start_code;
2127 prctl_map.end_code = mm->end_code;
2128 prctl_map.start_data = mm->start_data;
2129 prctl_map.end_data = mm->end_data;
2130 prctl_map.start_brk = mm->start_brk;
2131 prctl_map.brk = mm->brk;
2132 prctl_map.start_stack = mm->start_stack;
2133 prctl_map.arg_start = mm->arg_start;
2134 prctl_map.arg_end = mm->arg_end;
2135 prctl_map.env_start = mm->env_start;
2136 prctl_map.env_end = mm->env_end;
2137 prctl_map.auxv = NULL;
2138 prctl_map.auxv_size = 0;
2139 prctl_map.exe_fd = -1;
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(&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 argumets 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;
2215 out:
2216 up_write(&mm->mmap_sem);
2217 return error;
2218 }
2219
2220 #ifdef CONFIG_CHECKPOINT_RESTORE
2221 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2222 {
2223 return put_user(me->clear_child_tid, tid_addr);
2224 }
2225 #else
2226 static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr)
2227 {
2228 return -EINVAL;
2229 }
2230 #endif
2231
2232 static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2233 {
2234 /*
2235 * If task has has_child_subreaper - all its decendants
2236 * already have these flag too and new decendants will
2237 * inherit it on fork, skip them.
2238 *
2239 * If we've found child_reaper - skip descendants in
2240 * it's subtree as they will never get out pidns.
2241 */
2242 if (p->signal->has_child_subreaper ||
2243 is_child_reaper(task_pid(p)))
2244 return 0;
2245
2246 p->signal->has_child_subreaper = 1;
2247 return 1;
2248 }
2249
2250 int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
2251 {
2252 return -EINVAL;
2253 }
2254
2255 int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2256 unsigned long ctrl)
2257 {
2258 return -EINVAL;
2259 }
2260
2261 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2262 unsigned long, arg4, unsigned long, arg5)
2263 {
2264 struct task_struct *me = current;
2265 unsigned char comm[sizeof(me->comm)];
2266 long error;
2267
2268 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2269 if (error != -ENOSYS)
2270 return error;
2271
2272 error = 0;
2273 switch (option) {
2274 case PR_SET_PDEATHSIG:
2275 if (!valid_signal(arg2)) {
2276 error = -EINVAL;
2277 break;
2278 }
2279 me->pdeath_signal = arg2;
2280 break;
2281 case PR_GET_PDEATHSIG:
2282 error = put_user(me->pdeath_signal, (int __user *)arg2);
2283 break;
2284 case PR_GET_DUMPABLE:
2285 error = get_dumpable(me->mm);
2286 break;
2287 case PR_SET_DUMPABLE:
2288 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2289 error = -EINVAL;
2290 break;
2291 }
2292 set_dumpable(me->mm, arg2);
2293 break;
2294
2295 case PR_SET_UNALIGN:
2296 error = SET_UNALIGN_CTL(me, arg2);
2297 break;
2298 case PR_GET_UNALIGN:
2299 error = GET_UNALIGN_CTL(me, arg2);
2300 break;
2301 case PR_SET_FPEMU:
2302 error = SET_FPEMU_CTL(me, arg2);
2303 break;
2304 case PR_GET_FPEMU:
2305 error = GET_FPEMU_CTL(me, arg2);
2306 break;
2307 case PR_SET_FPEXC:
2308 error = SET_FPEXC_CTL(me, arg2);
2309 break;
2310 case PR_GET_FPEXC:
2311 error = GET_FPEXC_CTL(me, arg2);
2312 break;
2313 case PR_GET_TIMING:
2314 error = PR_TIMING_STATISTICAL;
2315 break;
2316 case PR_SET_TIMING:
2317 if (arg2 != PR_TIMING_STATISTICAL)
2318 error = -EINVAL;
2319 break;
2320 case PR_SET_NAME:
2321 comm[sizeof(me->comm) - 1] = 0;
2322 if (strncpy_from_user(comm, (char __user *)arg2,
2323 sizeof(me->comm) - 1) < 0)
2324 return -EFAULT;
2325 set_task_comm(me, comm);
2326 proc_comm_connector(me);
2327 break;
2328 case PR_GET_NAME:
2329 get_task_comm(comm, me);
2330 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2331 return -EFAULT;
2332 break;
2333 case PR_GET_ENDIAN:
2334 error = GET_ENDIAN(me, arg2);
2335 break;
2336 case PR_SET_ENDIAN:
2337 error = SET_ENDIAN(me, arg2);
2338 break;
2339 case PR_GET_SECCOMP:
2340 error = prctl_get_seccomp();
2341 break;
2342 case PR_SET_SECCOMP:
2343 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2344 break;
2345 case PR_GET_TSC:
2346 error = GET_TSC_CTL(arg2);
2347 break;
2348 case PR_SET_TSC:
2349 error = SET_TSC_CTL(arg2);
2350 break;
2351 case PR_TASK_PERF_EVENTS_DISABLE:
2352 error = perf_event_task_disable();
2353 break;
2354 case PR_TASK_PERF_EVENTS_ENABLE:
2355 error = perf_event_task_enable();
2356 break;
2357 case PR_GET_TIMERSLACK:
2358 if (current->timer_slack_ns > ULONG_MAX)
2359 error = ULONG_MAX;
2360 else
2361 error = current->timer_slack_ns;
2362 break;
2363 case PR_SET_TIMERSLACK:
2364 if (arg2 <= 0)
2365 current->timer_slack_ns =
2366 current->default_timer_slack_ns;
2367 else
2368 current->timer_slack_ns = arg2;
2369 break;
2370 case PR_MCE_KILL:
2371 if (arg4 | arg5)
2372 return -EINVAL;
2373 switch (arg2) {
2374 case PR_MCE_KILL_CLEAR:
2375 if (arg3 != 0)
2376 return -EINVAL;
2377 current->flags &= ~PF_MCE_PROCESS;
2378 break;
2379 case PR_MCE_KILL_SET:
2380 current->flags |= PF_MCE_PROCESS;
2381 if (arg3 == PR_MCE_KILL_EARLY)
2382 current->flags |= PF_MCE_EARLY;
2383 else if (arg3 == PR_MCE_KILL_LATE)
2384 current->flags &= ~PF_MCE_EARLY;
2385 else if (arg3 == PR_MCE_KILL_DEFAULT)
2386 current->flags &=
2387 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2388 else
2389 return -EINVAL;
2390 break;
2391 default:
2392 return -EINVAL;
2393 }
2394 break;
2395 case PR_MCE_KILL_GET:
2396 if (arg2 | arg3 | arg4 | arg5)
2397 return -EINVAL;
2398 if (current->flags & PF_MCE_PROCESS)
2399 error = (current->flags & PF_MCE_EARLY) ?
2400 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2401 else
2402 error = PR_MCE_KILL_DEFAULT;
2403 break;
2404 case PR_SET_MM:
2405 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2406 break;
2407 case PR_GET_TID_ADDRESS:
2408 error = prctl_get_tid_address(me, (int __user **)arg2);
2409 break;
2410 case PR_SET_CHILD_SUBREAPER:
2411 me->signal->is_child_subreaper = !!arg2;
2412 if (!arg2)
2413 break;
2414
2415 walk_process_tree(me, propagate_has_child_subreaper, NULL);
2416 break;
2417 case PR_GET_CHILD_SUBREAPER:
2418 error = put_user(me->signal->is_child_subreaper,
2419 (int __user *)arg2);
2420 break;
2421 case PR_SET_NO_NEW_PRIVS:
2422 if (arg2 != 1 || arg3 || arg4 || arg5)
2423 return -EINVAL;
2424
2425 task_set_no_new_privs(current);
2426 break;
2427 case PR_GET_NO_NEW_PRIVS:
2428 if (arg2 || arg3 || arg4 || arg5)
2429 return -EINVAL;
2430 return task_no_new_privs(current) ? 1 : 0;
2431 case PR_GET_THP_DISABLE:
2432 if (arg2 || arg3 || arg4 || arg5)
2433 return -EINVAL;
2434 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
2435 break;
2436 case PR_SET_THP_DISABLE:
2437 if (arg3 || arg4 || arg5)
2438 return -EINVAL;
2439 if (down_write_killable(&me->mm->mmap_sem))
2440 return -EINTR;
2441 if (arg2)
2442 set_bit(MMF_DISABLE_THP, &me->mm->flags);
2443 else
2444 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
2445 up_write(&me->mm->mmap_sem);
2446 break;
2447 case PR_MPX_ENABLE_MANAGEMENT:
2448 if (arg2 || arg3 || arg4 || arg5)
2449 return -EINVAL;
2450 error = MPX_ENABLE_MANAGEMENT();
2451 break;
2452 case PR_MPX_DISABLE_MANAGEMENT:
2453 if (arg2 || arg3 || arg4 || arg5)
2454 return -EINVAL;
2455 error = MPX_DISABLE_MANAGEMENT();
2456 break;
2457 case PR_SET_FP_MODE:
2458 error = SET_FP_MODE(me, arg2);
2459 break;
2460 case PR_GET_FP_MODE:
2461 error = GET_FP_MODE(me);
2462 break;
2463 case PR_SVE_SET_VL:
2464 error = SVE_SET_VL(arg2);
2465 break;
2466 case PR_SVE_GET_VL:
2467 error = SVE_GET_VL();
2468 break;
2469 case PR_GET_SPECULATION_CTRL:
2470 if (arg3 || arg4 || arg5)
2471 return -EINVAL;
2472 error = arch_prctl_spec_ctrl_get(me, arg2);
2473 break;
2474 case PR_SET_SPECULATION_CTRL:
2475 if (arg4 || arg5)
2476 return -EINVAL;
2477 error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
2478 break;
2479 default:
2480 error = -EINVAL;
2481 break;
2482 }
2483 return error;
2484 }
2485
2486 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2487 struct getcpu_cache __user *, unused)
2488 {
2489 int err = 0;
2490 int cpu = raw_smp_processor_id();
2491
2492 if (cpup)
2493 err |= put_user(cpu, cpup);
2494 if (nodep)
2495 err |= put_user(cpu_to_node(cpu), nodep);
2496 return err ? -EFAULT : 0;
2497 }
2498
2499 /**
2500 * do_sysinfo - fill in sysinfo struct
2501 * @info: pointer to buffer to fill
2502 */
2503 static int do_sysinfo(struct sysinfo *info)
2504 {
2505 unsigned long mem_total, sav_total;
2506 unsigned int mem_unit, bitcount;
2507 struct timespec64 tp;
2508
2509 memset(info, 0, sizeof(struct sysinfo));
2510
2511 ktime_get_boottime_ts64(&tp);
2512 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2513
2514 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2515
2516 info->procs = nr_threads;
2517
2518 si_meminfo(info);
2519 si_swapinfo(info);
2520
2521 /*
2522 * If the sum of all the available memory (i.e. ram + swap)
2523 * is less than can be stored in a 32 bit unsigned long then
2524 * we can be binary compatible with 2.2.x kernels. If not,
2525 * well, in that case 2.2.x was broken anyways...
2526 *
2527 * -Erik Andersen <andersee@debian.org>
2528 */
2529
2530 mem_total = info->totalram + info->totalswap;
2531 if (mem_total < info->totalram || mem_total < info->totalswap)
2532 goto out;
2533 bitcount = 0;
2534 mem_unit = info->mem_unit;
2535 while (mem_unit > 1) {
2536 bitcount++;
2537 mem_unit >>= 1;
2538 sav_total = mem_total;
2539 mem_total <<= 1;
2540 if (mem_total < sav_total)
2541 goto out;
2542 }
2543
2544 /*
2545 * If mem_total did not overflow, multiply all memory values by
2546 * info->mem_unit and set it to 1. This leaves things compatible
2547 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2548 * kernels...
2549 */
2550
2551 info->mem_unit = 1;
2552 info->totalram <<= bitcount;
2553 info->freeram <<= bitcount;
2554 info->sharedram <<= bitcount;
2555 info->bufferram <<= bitcount;
2556 info->totalswap <<= bitcount;
2557 info->freeswap <<= bitcount;
2558 info->totalhigh <<= bitcount;
2559 info->freehigh <<= bitcount;
2560
2561 out:
2562 return 0;
2563 }
2564
2565 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2566 {
2567 struct sysinfo val;
2568
2569 do_sysinfo(&val);
2570
2571 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2572 return -EFAULT;
2573
2574 return 0;
2575 }
2576
2577 #ifdef CONFIG_COMPAT
2578 struct compat_sysinfo {
2579 s32 uptime;
2580 u32 loads[3];
2581 u32 totalram;
2582 u32 freeram;
2583 u32 sharedram;
2584 u32 bufferram;
2585 u32 totalswap;
2586 u32 freeswap;
2587 u16 procs;
2588 u16 pad;
2589 u32 totalhigh;
2590 u32 freehigh;
2591 u32 mem_unit;
2592 char _f[20-2*sizeof(u32)-sizeof(int)];
2593 };
2594
2595 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2596 {
2597 struct sysinfo s;
2598
2599 do_sysinfo(&s);
2600
2601 /* Check to see if any memory value is too large for 32-bit and scale
2602 * down if needed
2603 */
2604 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2605 int bitcount = 0;
2606
2607 while (s.mem_unit < PAGE_SIZE) {
2608 s.mem_unit <<= 1;
2609 bitcount++;
2610 }
2611
2612 s.totalram >>= bitcount;
2613 s.freeram >>= bitcount;
2614 s.sharedram >>= bitcount;
2615 s.bufferram >>= bitcount;
2616 s.totalswap >>= bitcount;
2617 s.freeswap >>= bitcount;
2618 s.totalhigh >>= bitcount;
2619 s.freehigh >>= bitcount;
2620 }
2621
2622 if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
2623 __put_user(s.uptime, &info->uptime) ||
2624 __put_user(s.loads[0], &info->loads[0]) ||
2625 __put_user(s.loads[1], &info->loads[1]) ||
2626 __put_user(s.loads[2], &info->loads[2]) ||
2627 __put_user(s.totalram, &info->totalram) ||
2628 __put_user(s.freeram, &info->freeram) ||
2629 __put_user(s.sharedram, &info->sharedram) ||
2630 __put_user(s.bufferram, &info->bufferram) ||
2631 __put_user(s.totalswap, &info->totalswap) ||
2632 __put_user(s.freeswap, &info->freeswap) ||
2633 __put_user(s.procs, &info->procs) ||
2634 __put_user(s.totalhigh, &info->totalhigh) ||
2635 __put_user(s.freehigh, &info->freehigh) ||
2636 __put_user(s.mem_unit, &info->mem_unit))
2637 return -EFAULT;
2638
2639 return 0;
2640 }
2641 #endif /* CONFIG_COMPAT */
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