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/mm_inline.h>
11 #include <linux/utsname.h>
12 #include <linux/mman.h>
13 #include <linux/reboot.h>
14 #include <linux/prctl.h>
15 #include <linux/highuid.h>
16 #include <linux/fs.h>
17 #include <linux/kmod.h>
18 #include <linux/ksm.h>
19 #include <linux/perf_event.h>
20 #include <linux/resource.h>
21 #include <linux/kernel.h>
22 #include <linux/workqueue.h>
23 #include <linux/capability.h>
24 #include <linux/device.h>
25 #include <linux/key.h>
26 #include <linux/times.h>
27 #include <linux/posix-timers.h>
28 #include <linux/security.h>
29 #include <linux/random.h>
30 #include <linux/suspend.h>
31 #include <linux/tty.h>
32 #include <linux/signal.h>
33 #include <linux/cn_proc.h>
34 #include <linux/getcpu.h>
35 #include <linux/task_io_accounting_ops.h>
36 #include <linux/seccomp.h>
37 #include <linux/cpu.h>
38 #include <linux/personality.h>
39 #include <linux/ptrace.h>
40 #include <linux/fs_struct.h>
41 #include <linux/file.h>
42 #include <linux/mount.h>
43 #include <linux/gfp.h>
44 #include <linux/syscore_ops.h>
45 #include <linux/version.h>
46 #include <linux/ctype.h>
47 #include <linux/syscall_user_dispatch.h>
48
49 #include <linux/compat.h>
50 #include <linux/syscalls.h>
51 #include <linux/kprobes.h>
52 #include <linux/user_namespace.h>
53 #include <linux/time_namespace.h>
54 #include <linux/binfmts.h>
55
56 #include <linux/sched.h>
57 #include <linux/sched/autogroup.h>
58 #include <linux/sched/loadavg.h>
59 #include <linux/sched/stat.h>
60 #include <linux/sched/mm.h>
61 #include <linux/sched/coredump.h>
62 #include <linux/sched/task.h>
63 #include <linux/sched/cputime.h>
64 #include <linux/rcupdate.h>
65 #include <linux/uidgid.h>
66 #include <linux/cred.h>
67
68 #include <linux/nospec.h>
69
70 #include <linux/kmsg_dump.h>
71 /* Move somewhere else to avoid recompiling? */
72 #include <generated/utsrelease.h>
73
74 #include <linux/uaccess.h>
75 #include <asm/io.h>
76 #include <asm/unistd.h>
77
78 #include <trace/events/task.h>
79
80 #include "uid16.h"
81
82 #ifndef SET_UNALIGN_CTL
83 # define SET_UNALIGN_CTL(a, b) (-EINVAL)
84 #endif
85 #ifndef GET_UNALIGN_CTL
86 # define GET_UNALIGN_CTL(a, b) (-EINVAL)
87 #endif
88 #ifndef SET_FPEMU_CTL
89 # define SET_FPEMU_CTL(a, b) (-EINVAL)
90 #endif
91 #ifndef GET_FPEMU_CTL
92 # define GET_FPEMU_CTL(a, b) (-EINVAL)
93 #endif
94 #ifndef SET_FPEXC_CTL
95 # define SET_FPEXC_CTL(a, b) (-EINVAL)
96 #endif
97 #ifndef GET_FPEXC_CTL
98 # define GET_FPEXC_CTL(a, b) (-EINVAL)
99 #endif
100 #ifndef GET_ENDIAN
101 # define GET_ENDIAN(a, b) (-EINVAL)
102 #endif
103 #ifndef SET_ENDIAN
104 # define SET_ENDIAN(a, b) (-EINVAL)
105 #endif
106 #ifndef GET_TSC_CTL
107 # define GET_TSC_CTL(a) (-EINVAL)
108 #endif
109 #ifndef SET_TSC_CTL
110 # define SET_TSC_CTL(a) (-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 #ifndef SME_SET_VL
125 # define SME_SET_VL(a) (-EINVAL)
126 #endif
127 #ifndef SME_GET_VL
128 # define SME_GET_VL() (-EINVAL)
129 #endif
130 #ifndef PAC_RESET_KEYS
131 # define PAC_RESET_KEYS(a, b) (-EINVAL)
132 #endif
133 #ifndef PAC_SET_ENABLED_KEYS
134 # define PAC_SET_ENABLED_KEYS(a, b, c) (-EINVAL)
135 #endif
136 #ifndef PAC_GET_ENABLED_KEYS
137 # define PAC_GET_ENABLED_KEYS(a) (-EINVAL)
138 #endif
139 #ifndef SET_TAGGED_ADDR_CTRL
140 # define SET_TAGGED_ADDR_CTRL(a) (-EINVAL)
141 #endif
142 #ifndef GET_TAGGED_ADDR_CTRL
143 # define GET_TAGGED_ADDR_CTRL() (-EINVAL)
144 #endif
145 #ifndef RISCV_V_SET_CONTROL
146 # define RISCV_V_SET_CONTROL(a) (-EINVAL)
147 #endif
148 #ifndef RISCV_V_GET_CONTROL
149 # define RISCV_V_GET_CONTROL() (-EINVAL)
150 #endif
151 #ifndef RISCV_SET_ICACHE_FLUSH_CTX
152 # define RISCV_SET_ICACHE_FLUSH_CTX(a, b) (-EINVAL)
153 #endif
154 #ifndef PPC_GET_DEXCR_ASPECT
155 # define PPC_GET_DEXCR_ASPECT(a, b) (-EINVAL)
156 #endif
157 #ifndef PPC_SET_DEXCR_ASPECT
158 # define PPC_SET_DEXCR_ASPECT(a, b, c) (-EINVAL)
159 #endif
160
161 /*
162 * this is where the system-wide overflow UID and GID are defined, for
163 * architectures that now have 32-bit UID/GID but didn't in the past
164 */
165
166 int overflowuid = DEFAULT_OVERFLOWUID;
167 int overflowgid = DEFAULT_OVERFLOWGID;
168
169 EXPORT_SYMBOL(overflowuid);
170 EXPORT_SYMBOL(overflowgid);
171
172 /*
173 * the same as above, but for filesystems which can only store a 16-bit
174 * UID and GID. as such, this is needed on all architectures
175 */
176
177 int fs_overflowuid = DEFAULT_FS_OVERFLOWUID;
178 int fs_overflowgid = DEFAULT_FS_OVERFLOWGID;
179
180 EXPORT_SYMBOL(fs_overflowuid);
181 EXPORT_SYMBOL(fs_overflowgid);
182
183 /*
184 * Returns true if current's euid is same as p's uid or euid,
185 * or has CAP_SYS_NICE to p's user_ns.
186 *
187 * Called with rcu_read_lock, creds are safe
188 */
set_one_prio_perm(struct task_struct * p)189 static bool set_one_prio_perm(struct task_struct *p)
190 {
191 const struct cred *cred = current_cred(), *pcred = __task_cred(p);
192
193 if (uid_eq(pcred->uid, cred->euid) ||
194 uid_eq(pcred->euid, cred->euid))
195 return true;
196 if (ns_capable(pcred->user_ns, CAP_SYS_NICE))
197 return true;
198 return false;
199 }
200
201 /*
202 * set the priority of a task
203 * - the caller must hold the RCU read lock
204 */
set_one_prio(struct task_struct * p,int niceval,int error)205 static int set_one_prio(struct task_struct *p, int niceval, int error)
206 {
207 int no_nice;
208
209 if (!set_one_prio_perm(p)) {
210 error = -EPERM;
211 goto out;
212 }
213 if (niceval < task_nice(p) && !can_nice(p, niceval)) {
214 error = -EACCES;
215 goto out;
216 }
217 no_nice = security_task_setnice(p, niceval);
218 if (no_nice) {
219 error = no_nice;
220 goto out;
221 }
222 if (error == -ESRCH)
223 error = 0;
224 set_user_nice(p, niceval);
225 out:
226 return error;
227 }
228
SYSCALL_DEFINE3(setpriority,int,which,int,who,int,niceval)229 SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval)
230 {
231 struct task_struct *g, *p;
232 struct user_struct *user;
233 const struct cred *cred = current_cred();
234 int error = -EINVAL;
235 struct pid *pgrp;
236 kuid_t uid;
237
238 if (which > PRIO_USER || which < PRIO_PROCESS)
239 goto out;
240
241 /* normalize: avoid signed division (rounding problems) */
242 error = -ESRCH;
243 if (niceval < MIN_NICE)
244 niceval = MIN_NICE;
245 if (niceval > MAX_NICE)
246 niceval = MAX_NICE;
247
248 rcu_read_lock();
249 switch (which) {
250 case PRIO_PROCESS:
251 if (who)
252 p = find_task_by_vpid(who);
253 else
254 p = current;
255 if (p)
256 error = set_one_prio(p, niceval, error);
257 break;
258 case PRIO_PGRP:
259 if (who)
260 pgrp = find_vpid(who);
261 else
262 pgrp = task_pgrp(current);
263 read_lock(&tasklist_lock);
264 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
265 error = set_one_prio(p, niceval, error);
266 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
267 read_unlock(&tasklist_lock);
268 break;
269 case PRIO_USER:
270 uid = make_kuid(cred->user_ns, who);
271 user = cred->user;
272 if (!who)
273 uid = cred->uid;
274 else if (!uid_eq(uid, cred->uid)) {
275 user = find_user(uid);
276 if (!user)
277 goto out_unlock; /* No processes for this user */
278 }
279 for_each_process_thread(g, p) {
280 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p))
281 error = set_one_prio(p, niceval, error);
282 }
283 if (!uid_eq(uid, cred->uid))
284 free_uid(user); /* For find_user() */
285 break;
286 }
287 out_unlock:
288 rcu_read_unlock();
289 out:
290 return error;
291 }
292
293 /*
294 * Ugh. To avoid negative return values, "getpriority()" will
295 * not return the normal nice-value, but a negated value that
296 * has been offset by 20 (ie it returns 40..1 instead of -20..19)
297 * to stay compatible.
298 */
SYSCALL_DEFINE2(getpriority,int,which,int,who)299 SYSCALL_DEFINE2(getpriority, int, which, int, who)
300 {
301 struct task_struct *g, *p;
302 struct user_struct *user;
303 const struct cred *cred = current_cred();
304 long niceval, retval = -ESRCH;
305 struct pid *pgrp;
306 kuid_t uid;
307
308 if (which > PRIO_USER || which < PRIO_PROCESS)
309 return -EINVAL;
310
311 rcu_read_lock();
312 switch (which) {
313 case PRIO_PROCESS:
314 if (who)
315 p = find_task_by_vpid(who);
316 else
317 p = current;
318 if (p) {
319 niceval = nice_to_rlimit(task_nice(p));
320 if (niceval > retval)
321 retval = niceval;
322 }
323 break;
324 case PRIO_PGRP:
325 if (who)
326 pgrp = find_vpid(who);
327 else
328 pgrp = task_pgrp(current);
329 read_lock(&tasklist_lock);
330 do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
331 niceval = nice_to_rlimit(task_nice(p));
332 if (niceval > retval)
333 retval = niceval;
334 } while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
335 read_unlock(&tasklist_lock);
336 break;
337 case PRIO_USER:
338 uid = make_kuid(cred->user_ns, who);
339 user = cred->user;
340 if (!who)
341 uid = cred->uid;
342 else if (!uid_eq(uid, cred->uid)) {
343 user = find_user(uid);
344 if (!user)
345 goto out_unlock; /* No processes for this user */
346 }
347 for_each_process_thread(g, p) {
348 if (uid_eq(task_uid(p), uid) && task_pid_vnr(p)) {
349 niceval = nice_to_rlimit(task_nice(p));
350 if (niceval > retval)
351 retval = niceval;
352 }
353 }
354 if (!uid_eq(uid, cred->uid))
355 free_uid(user); /* for find_user() */
356 break;
357 }
358 out_unlock:
359 rcu_read_unlock();
360
361 return retval;
362 }
363
364 /*
365 * Unprivileged users may change the real gid to the effective gid
366 * or vice versa. (BSD-style)
367 *
368 * If you set the real gid at all, or set the effective gid to a value not
369 * equal to the real gid, then the saved gid is set to the new effective gid.
370 *
371 * This makes it possible for a setgid program to completely drop its
372 * privileges, which is often a useful assertion to make when you are doing
373 * a security audit over a program.
374 *
375 * The general idea is that a program which uses just setregid() will be
376 * 100% compatible with BSD. A program which uses just setgid() will be
377 * 100% compatible with POSIX with saved IDs.
378 *
379 * SMP: There are not races, the GIDs are checked only by filesystem
380 * operations (as far as semantic preservation is concerned).
381 */
382 #ifdef CONFIG_MULTIUSER
__sys_setregid(gid_t rgid,gid_t egid)383 long __sys_setregid(gid_t rgid, gid_t egid)
384 {
385 struct user_namespace *ns = current_user_ns();
386 const struct cred *old;
387 struct cred *new;
388 int retval;
389 kgid_t krgid, kegid;
390
391 krgid = make_kgid(ns, rgid);
392 kegid = make_kgid(ns, egid);
393
394 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
395 return -EINVAL;
396 if ((egid != (gid_t) -1) && !gid_valid(kegid))
397 return -EINVAL;
398
399 new = prepare_creds();
400 if (!new)
401 return -ENOMEM;
402 old = current_cred();
403
404 retval = -EPERM;
405 if (rgid != (gid_t) -1) {
406 if (gid_eq(old->gid, krgid) ||
407 gid_eq(old->egid, krgid) ||
408 ns_capable_setid(old->user_ns, CAP_SETGID))
409 new->gid = krgid;
410 else
411 goto error;
412 }
413 if (egid != (gid_t) -1) {
414 if (gid_eq(old->gid, kegid) ||
415 gid_eq(old->egid, kegid) ||
416 gid_eq(old->sgid, kegid) ||
417 ns_capable_setid(old->user_ns, CAP_SETGID))
418 new->egid = kegid;
419 else
420 goto error;
421 }
422
423 if (rgid != (gid_t) -1 ||
424 (egid != (gid_t) -1 && !gid_eq(kegid, old->gid)))
425 new->sgid = new->egid;
426 new->fsgid = new->egid;
427
428 retval = security_task_fix_setgid(new, old, LSM_SETID_RE);
429 if (retval < 0)
430 goto error;
431
432 return commit_creds(new);
433
434 error:
435 abort_creds(new);
436 return retval;
437 }
438
SYSCALL_DEFINE2(setregid,gid_t,rgid,gid_t,egid)439 SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
440 {
441 return __sys_setregid(rgid, egid);
442 }
443
444 /*
445 * setgid() is implemented like SysV w/ SAVED_IDS
446 *
447 * SMP: Same implicit races as above.
448 */
__sys_setgid(gid_t gid)449 long __sys_setgid(gid_t gid)
450 {
451 struct user_namespace *ns = current_user_ns();
452 const struct cred *old;
453 struct cred *new;
454 int retval;
455 kgid_t kgid;
456
457 kgid = make_kgid(ns, gid);
458 if (!gid_valid(kgid))
459 return -EINVAL;
460
461 new = prepare_creds();
462 if (!new)
463 return -ENOMEM;
464 old = current_cred();
465
466 retval = -EPERM;
467 if (ns_capable_setid(old->user_ns, CAP_SETGID))
468 new->gid = new->egid = new->sgid = new->fsgid = kgid;
469 else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid))
470 new->egid = new->fsgid = kgid;
471 else
472 goto error;
473
474 retval = security_task_fix_setgid(new, old, LSM_SETID_ID);
475 if (retval < 0)
476 goto error;
477
478 return commit_creds(new);
479
480 error:
481 abort_creds(new);
482 return retval;
483 }
484
SYSCALL_DEFINE1(setgid,gid_t,gid)485 SYSCALL_DEFINE1(setgid, gid_t, gid)
486 {
487 return __sys_setgid(gid);
488 }
489
490 /*
491 * change the user struct in a credentials set to match the new UID
492 */
set_user(struct cred * new)493 static int set_user(struct cred *new)
494 {
495 struct user_struct *new_user;
496
497 new_user = alloc_uid(new->uid);
498 if (!new_user)
499 return -EAGAIN;
500
501 free_uid(new->user);
502 new->user = new_user;
503 return 0;
504 }
505
flag_nproc_exceeded(struct cred * new)506 static void flag_nproc_exceeded(struct cred *new)
507 {
508 if (new->ucounts == current_ucounts())
509 return;
510
511 /*
512 * We don't fail in case of NPROC limit excess here because too many
513 * poorly written programs don't check set*uid() return code, assuming
514 * it never fails if called by root. We may still enforce NPROC limit
515 * for programs doing set*uid()+execve() by harmlessly deferring the
516 * failure to the execve() stage.
517 */
518 if (is_rlimit_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) &&
519 new->user != INIT_USER)
520 current->flags |= PF_NPROC_EXCEEDED;
521 else
522 current->flags &= ~PF_NPROC_EXCEEDED;
523 }
524
525 /*
526 * Unprivileged users may change the real uid to the effective uid
527 * or vice versa. (BSD-style)
528 *
529 * If you set the real uid at all, or set the effective uid to a value not
530 * equal to the real uid, then the saved uid is set to the new effective uid.
531 *
532 * This makes it possible for a setuid program to completely drop its
533 * privileges, which is often a useful assertion to make when you are doing
534 * a security audit over a program.
535 *
536 * The general idea is that a program which uses just setreuid() will be
537 * 100% compatible with BSD. A program which uses just setuid() will be
538 * 100% compatible with POSIX with saved IDs.
539 */
__sys_setreuid(uid_t ruid,uid_t euid)540 long __sys_setreuid(uid_t ruid, uid_t euid)
541 {
542 struct user_namespace *ns = current_user_ns();
543 const struct cred *old;
544 struct cred *new;
545 int retval;
546 kuid_t kruid, keuid;
547
548 kruid = make_kuid(ns, ruid);
549 keuid = make_kuid(ns, euid);
550
551 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
552 return -EINVAL;
553 if ((euid != (uid_t) -1) && !uid_valid(keuid))
554 return -EINVAL;
555
556 new = prepare_creds();
557 if (!new)
558 return -ENOMEM;
559 old = current_cred();
560
561 retval = -EPERM;
562 if (ruid != (uid_t) -1) {
563 new->uid = kruid;
564 if (!uid_eq(old->uid, kruid) &&
565 !uid_eq(old->euid, kruid) &&
566 !ns_capable_setid(old->user_ns, CAP_SETUID))
567 goto error;
568 }
569
570 if (euid != (uid_t) -1) {
571 new->euid = keuid;
572 if (!uid_eq(old->uid, keuid) &&
573 !uid_eq(old->euid, keuid) &&
574 !uid_eq(old->suid, keuid) &&
575 !ns_capable_setid(old->user_ns, CAP_SETUID))
576 goto error;
577 }
578
579 if (!uid_eq(new->uid, old->uid)) {
580 retval = set_user(new);
581 if (retval < 0)
582 goto error;
583 }
584 if (ruid != (uid_t) -1 ||
585 (euid != (uid_t) -1 && !uid_eq(keuid, old->uid)))
586 new->suid = new->euid;
587 new->fsuid = new->euid;
588
589 retval = security_task_fix_setuid(new, old, LSM_SETID_RE);
590 if (retval < 0)
591 goto error;
592
593 retval = set_cred_ucounts(new);
594 if (retval < 0)
595 goto error;
596
597 flag_nproc_exceeded(new);
598 return commit_creds(new);
599
600 error:
601 abort_creds(new);
602 return retval;
603 }
604
SYSCALL_DEFINE2(setreuid,uid_t,ruid,uid_t,euid)605 SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid)
606 {
607 return __sys_setreuid(ruid, euid);
608 }
609
610 /*
611 * setuid() is implemented like SysV with SAVED_IDS
612 *
613 * Note that SAVED_ID's is deficient in that a setuid root program
614 * like sendmail, for example, cannot set its uid to be a normal
615 * user and then switch back, because if you're root, setuid() sets
616 * the saved uid too. If you don't like this, blame the bright people
617 * in the POSIX committee and/or USG. Note that the BSD-style setreuid()
618 * will allow a root program to temporarily drop privileges and be able to
619 * regain them by swapping the real and effective uid.
620 */
__sys_setuid(uid_t uid)621 long __sys_setuid(uid_t uid)
622 {
623 struct user_namespace *ns = current_user_ns();
624 const struct cred *old;
625 struct cred *new;
626 int retval;
627 kuid_t kuid;
628
629 kuid = make_kuid(ns, uid);
630 if (!uid_valid(kuid))
631 return -EINVAL;
632
633 new = prepare_creds();
634 if (!new)
635 return -ENOMEM;
636 old = current_cred();
637
638 retval = -EPERM;
639 if (ns_capable_setid(old->user_ns, CAP_SETUID)) {
640 new->suid = new->uid = kuid;
641 if (!uid_eq(kuid, old->uid)) {
642 retval = set_user(new);
643 if (retval < 0)
644 goto error;
645 }
646 } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) {
647 goto error;
648 }
649
650 new->fsuid = new->euid = kuid;
651
652 retval = security_task_fix_setuid(new, old, LSM_SETID_ID);
653 if (retval < 0)
654 goto error;
655
656 retval = set_cred_ucounts(new);
657 if (retval < 0)
658 goto error;
659
660 flag_nproc_exceeded(new);
661 return commit_creds(new);
662
663 error:
664 abort_creds(new);
665 return retval;
666 }
667
SYSCALL_DEFINE1(setuid,uid_t,uid)668 SYSCALL_DEFINE1(setuid, uid_t, uid)
669 {
670 return __sys_setuid(uid);
671 }
672
673
674 /*
675 * This function implements a generic ability to update ruid, euid,
676 * and suid. This allows you to implement the 4.4 compatible seteuid().
677 */
__sys_setresuid(uid_t ruid,uid_t euid,uid_t suid)678 long __sys_setresuid(uid_t ruid, uid_t euid, uid_t suid)
679 {
680 struct user_namespace *ns = current_user_ns();
681 const struct cred *old;
682 struct cred *new;
683 int retval;
684 kuid_t kruid, keuid, ksuid;
685 bool ruid_new, euid_new, suid_new;
686
687 kruid = make_kuid(ns, ruid);
688 keuid = make_kuid(ns, euid);
689 ksuid = make_kuid(ns, suid);
690
691 if ((ruid != (uid_t) -1) && !uid_valid(kruid))
692 return -EINVAL;
693
694 if ((euid != (uid_t) -1) && !uid_valid(keuid))
695 return -EINVAL;
696
697 if ((suid != (uid_t) -1) && !uid_valid(ksuid))
698 return -EINVAL;
699
700 old = current_cred();
701
702 /* check for no-op */
703 if ((ruid == (uid_t) -1 || uid_eq(kruid, old->uid)) &&
704 (euid == (uid_t) -1 || (uid_eq(keuid, old->euid) &&
705 uid_eq(keuid, old->fsuid))) &&
706 (suid == (uid_t) -1 || uid_eq(ksuid, old->suid)))
707 return 0;
708
709 ruid_new = ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) &&
710 !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid);
711 euid_new = euid != (uid_t) -1 && !uid_eq(keuid, old->uid) &&
712 !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid);
713 suid_new = suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) &&
714 !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid);
715 if ((ruid_new || euid_new || suid_new) &&
716 !ns_capable_setid(old->user_ns, CAP_SETUID))
717 return -EPERM;
718
719 new = prepare_creds();
720 if (!new)
721 return -ENOMEM;
722
723 if (ruid != (uid_t) -1) {
724 new->uid = kruid;
725 if (!uid_eq(kruid, old->uid)) {
726 retval = set_user(new);
727 if (retval < 0)
728 goto error;
729 }
730 }
731 if (euid != (uid_t) -1)
732 new->euid = keuid;
733 if (suid != (uid_t) -1)
734 new->suid = ksuid;
735 new->fsuid = new->euid;
736
737 retval = security_task_fix_setuid(new, old, LSM_SETID_RES);
738 if (retval < 0)
739 goto error;
740
741 retval = set_cred_ucounts(new);
742 if (retval < 0)
743 goto error;
744
745 flag_nproc_exceeded(new);
746 return commit_creds(new);
747
748 error:
749 abort_creds(new);
750 return retval;
751 }
752
SYSCALL_DEFINE3(setresuid,uid_t,ruid,uid_t,euid,uid_t,suid)753 SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid)
754 {
755 return __sys_setresuid(ruid, euid, suid);
756 }
757
SYSCALL_DEFINE3(getresuid,uid_t __user *,ruidp,uid_t __user *,euidp,uid_t __user *,suidp)758 SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp)
759 {
760 const struct cred *cred = current_cred();
761 int retval;
762 uid_t ruid, euid, suid;
763
764 ruid = from_kuid_munged(cred->user_ns, cred->uid);
765 euid = from_kuid_munged(cred->user_ns, cred->euid);
766 suid = from_kuid_munged(cred->user_ns, cred->suid);
767
768 retval = put_user(ruid, ruidp);
769 if (!retval) {
770 retval = put_user(euid, euidp);
771 if (!retval)
772 return put_user(suid, suidp);
773 }
774 return retval;
775 }
776
777 /*
778 * Same as above, but for rgid, egid, sgid.
779 */
__sys_setresgid(gid_t rgid,gid_t egid,gid_t sgid)780 long __sys_setresgid(gid_t rgid, gid_t egid, gid_t sgid)
781 {
782 struct user_namespace *ns = current_user_ns();
783 const struct cred *old;
784 struct cred *new;
785 int retval;
786 kgid_t krgid, kegid, ksgid;
787 bool rgid_new, egid_new, sgid_new;
788
789 krgid = make_kgid(ns, rgid);
790 kegid = make_kgid(ns, egid);
791 ksgid = make_kgid(ns, sgid);
792
793 if ((rgid != (gid_t) -1) && !gid_valid(krgid))
794 return -EINVAL;
795 if ((egid != (gid_t) -1) && !gid_valid(kegid))
796 return -EINVAL;
797 if ((sgid != (gid_t) -1) && !gid_valid(ksgid))
798 return -EINVAL;
799
800 old = current_cred();
801
802 /* check for no-op */
803 if ((rgid == (gid_t) -1 || gid_eq(krgid, old->gid)) &&
804 (egid == (gid_t) -1 || (gid_eq(kegid, old->egid) &&
805 gid_eq(kegid, old->fsgid))) &&
806 (sgid == (gid_t) -1 || gid_eq(ksgid, old->sgid)))
807 return 0;
808
809 rgid_new = rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) &&
810 !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid);
811 egid_new = egid != (gid_t) -1 && !gid_eq(kegid, old->gid) &&
812 !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid);
813 sgid_new = sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) &&
814 !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid);
815 if ((rgid_new || egid_new || sgid_new) &&
816 !ns_capable_setid(old->user_ns, CAP_SETGID))
817 return -EPERM;
818
819 new = prepare_creds();
820 if (!new)
821 return -ENOMEM;
822
823 if (rgid != (gid_t) -1)
824 new->gid = krgid;
825 if (egid != (gid_t) -1)
826 new->egid = kegid;
827 if (sgid != (gid_t) -1)
828 new->sgid = ksgid;
829 new->fsgid = new->egid;
830
831 retval = security_task_fix_setgid(new, old, LSM_SETID_RES);
832 if (retval < 0)
833 goto error;
834
835 return commit_creds(new);
836
837 error:
838 abort_creds(new);
839 return retval;
840 }
841
SYSCALL_DEFINE3(setresgid,gid_t,rgid,gid_t,egid,gid_t,sgid)842 SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid)
843 {
844 return __sys_setresgid(rgid, egid, sgid);
845 }
846
SYSCALL_DEFINE3(getresgid,gid_t __user *,rgidp,gid_t __user *,egidp,gid_t __user *,sgidp)847 SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp)
848 {
849 const struct cred *cred = current_cred();
850 int retval;
851 gid_t rgid, egid, sgid;
852
853 rgid = from_kgid_munged(cred->user_ns, cred->gid);
854 egid = from_kgid_munged(cred->user_ns, cred->egid);
855 sgid = from_kgid_munged(cred->user_ns, cred->sgid);
856
857 retval = put_user(rgid, rgidp);
858 if (!retval) {
859 retval = put_user(egid, egidp);
860 if (!retval)
861 retval = put_user(sgid, sgidp);
862 }
863
864 return retval;
865 }
866
867
868 /*
869 * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This
870 * is used for "access()" and for the NFS daemon (letting nfsd stay at
871 * whatever uid it wants to). It normally shadows "euid", except when
872 * explicitly set by setfsuid() or for access..
873 */
__sys_setfsuid(uid_t uid)874 long __sys_setfsuid(uid_t uid)
875 {
876 const struct cred *old;
877 struct cred *new;
878 uid_t old_fsuid;
879 kuid_t kuid;
880
881 old = current_cred();
882 old_fsuid = from_kuid_munged(old->user_ns, old->fsuid);
883
884 kuid = make_kuid(old->user_ns, uid);
885 if (!uid_valid(kuid))
886 return old_fsuid;
887
888 new = prepare_creds();
889 if (!new)
890 return old_fsuid;
891
892 if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) ||
893 uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) ||
894 ns_capable_setid(old->user_ns, CAP_SETUID)) {
895 if (!uid_eq(kuid, old->fsuid)) {
896 new->fsuid = kuid;
897 if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0)
898 goto change_okay;
899 }
900 }
901
902 abort_creds(new);
903 return old_fsuid;
904
905 change_okay:
906 commit_creds(new);
907 return old_fsuid;
908 }
909
SYSCALL_DEFINE1(setfsuid,uid_t,uid)910 SYSCALL_DEFINE1(setfsuid, uid_t, uid)
911 {
912 return __sys_setfsuid(uid);
913 }
914
915 /*
916 * Samma på svenska..
917 */
__sys_setfsgid(gid_t gid)918 long __sys_setfsgid(gid_t gid)
919 {
920 const struct cred *old;
921 struct cred *new;
922 gid_t old_fsgid;
923 kgid_t kgid;
924
925 old = current_cred();
926 old_fsgid = from_kgid_munged(old->user_ns, old->fsgid);
927
928 kgid = make_kgid(old->user_ns, gid);
929 if (!gid_valid(kgid))
930 return old_fsgid;
931
932 new = prepare_creds();
933 if (!new)
934 return old_fsgid;
935
936 if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) ||
937 gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) ||
938 ns_capable_setid(old->user_ns, CAP_SETGID)) {
939 if (!gid_eq(kgid, old->fsgid)) {
940 new->fsgid = kgid;
941 if (security_task_fix_setgid(new,old,LSM_SETID_FS) == 0)
942 goto change_okay;
943 }
944 }
945
946 abort_creds(new);
947 return old_fsgid;
948
949 change_okay:
950 commit_creds(new);
951 return old_fsgid;
952 }
953
SYSCALL_DEFINE1(setfsgid,gid_t,gid)954 SYSCALL_DEFINE1(setfsgid, gid_t, gid)
955 {
956 return __sys_setfsgid(gid);
957 }
958 #endif /* CONFIG_MULTIUSER */
959
960 /**
961 * sys_getpid - return the thread group id of the current process
962 *
963 * Note, despite the name, this returns the tgid not the pid. The tgid and
964 * the pid are identical unless CLONE_THREAD was specified on clone() in
965 * which case the tgid is the same in all threads of the same group.
966 *
967 * This is SMP safe as current->tgid does not change.
968 */
SYSCALL_DEFINE0(getpid)969 SYSCALL_DEFINE0(getpid)
970 {
971 return task_tgid_vnr(current);
972 }
973
974 /* Thread ID - the internal kernel "pid" */
SYSCALL_DEFINE0(gettid)975 SYSCALL_DEFINE0(gettid)
976 {
977 return task_pid_vnr(current);
978 }
979
980 /*
981 * Accessing ->real_parent is not SMP-safe, it could
982 * change from under us. However, we can use a stale
983 * value of ->real_parent under rcu_read_lock(), see
984 * release_task()->call_rcu(delayed_put_task_struct).
985 */
SYSCALL_DEFINE0(getppid)986 SYSCALL_DEFINE0(getppid)
987 {
988 int pid;
989
990 rcu_read_lock();
991 pid = task_tgid_vnr(rcu_dereference(current->real_parent));
992 rcu_read_unlock();
993
994 return pid;
995 }
996
SYSCALL_DEFINE0(getuid)997 SYSCALL_DEFINE0(getuid)
998 {
999 /* Only we change this so SMP safe */
1000 return from_kuid_munged(current_user_ns(), current_uid());
1001 }
1002
SYSCALL_DEFINE0(geteuid)1003 SYSCALL_DEFINE0(geteuid)
1004 {
1005 /* Only we change this so SMP safe */
1006 return from_kuid_munged(current_user_ns(), current_euid());
1007 }
1008
SYSCALL_DEFINE0(getgid)1009 SYSCALL_DEFINE0(getgid)
1010 {
1011 /* Only we change this so SMP safe */
1012 return from_kgid_munged(current_user_ns(), current_gid());
1013 }
1014
SYSCALL_DEFINE0(getegid)1015 SYSCALL_DEFINE0(getegid)
1016 {
1017 /* Only we change this so SMP safe */
1018 return from_kgid_munged(current_user_ns(), current_egid());
1019 }
1020
do_sys_times(struct tms * tms)1021 static void do_sys_times(struct tms *tms)
1022 {
1023 u64 tgutime, tgstime, cutime, cstime;
1024
1025 thread_group_cputime_adjusted(current, &tgutime, &tgstime);
1026 cutime = current->signal->cutime;
1027 cstime = current->signal->cstime;
1028 tms->tms_utime = nsec_to_clock_t(tgutime);
1029 tms->tms_stime = nsec_to_clock_t(tgstime);
1030 tms->tms_cutime = nsec_to_clock_t(cutime);
1031 tms->tms_cstime = nsec_to_clock_t(cstime);
1032 }
1033
SYSCALL_DEFINE1(times,struct tms __user *,tbuf)1034 SYSCALL_DEFINE1(times, struct tms __user *, tbuf)
1035 {
1036 if (tbuf) {
1037 struct tms tmp;
1038
1039 do_sys_times(&tmp);
1040 if (copy_to_user(tbuf, &tmp, sizeof(struct tms)))
1041 return -EFAULT;
1042 }
1043 force_successful_syscall_return();
1044 return (long) jiffies_64_to_clock_t(get_jiffies_64());
1045 }
1046
1047 #ifdef CONFIG_COMPAT
clock_t_to_compat_clock_t(clock_t x)1048 static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
1049 {
1050 return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
1051 }
1052
COMPAT_SYSCALL_DEFINE1(times,struct compat_tms __user *,tbuf)1053 COMPAT_SYSCALL_DEFINE1(times, struct compat_tms __user *, tbuf)
1054 {
1055 if (tbuf) {
1056 struct tms tms;
1057 struct compat_tms tmp;
1058
1059 do_sys_times(&tms);
1060 /* Convert our struct tms to the compat version. */
1061 tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
1062 tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
1063 tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
1064 tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
1065 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
1066 return -EFAULT;
1067 }
1068 force_successful_syscall_return();
1069 return compat_jiffies_to_clock_t(jiffies);
1070 }
1071 #endif
1072
1073 /*
1074 * This needs some heavy checking ...
1075 * I just haven't the stomach for it. I also don't fully
1076 * understand sessions/pgrp etc. Let somebody who does explain it.
1077 *
1078 * OK, I think I have the protection semantics right.... this is really
1079 * only important on a multi-user system anyway, to make sure one user
1080 * can't send a signal to a process owned by another. -TYT, 12/12/91
1081 *
1082 * !PF_FORKNOEXEC check to conform completely to POSIX.
1083 */
SYSCALL_DEFINE2(setpgid,pid_t,pid,pid_t,pgid)1084 SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid)
1085 {
1086 struct task_struct *p;
1087 struct task_struct *group_leader = current->group_leader;
1088 struct pid *pgrp;
1089 int err;
1090
1091 if (!pid)
1092 pid = task_pid_vnr(group_leader);
1093 if (!pgid)
1094 pgid = pid;
1095 if (pgid < 0)
1096 return -EINVAL;
1097 rcu_read_lock();
1098
1099 /* From this point forward we keep holding onto the tasklist lock
1100 * so that our parent does not change from under us. -DaveM
1101 */
1102 write_lock_irq(&tasklist_lock);
1103
1104 err = -ESRCH;
1105 p = find_task_by_vpid(pid);
1106 if (!p)
1107 goto out;
1108
1109 err = -EINVAL;
1110 if (!thread_group_leader(p))
1111 goto out;
1112
1113 if (same_thread_group(p->real_parent, group_leader)) {
1114 err = -EPERM;
1115 if (task_session(p) != task_session(group_leader))
1116 goto out;
1117 err = -EACCES;
1118 if (!(p->flags & PF_FORKNOEXEC))
1119 goto out;
1120 } else {
1121 err = -ESRCH;
1122 if (p != group_leader)
1123 goto out;
1124 }
1125
1126 err = -EPERM;
1127 if (p->signal->leader)
1128 goto out;
1129
1130 pgrp = task_pid(p);
1131 if (pgid != pid) {
1132 struct task_struct *g;
1133
1134 pgrp = find_vpid(pgid);
1135 g = pid_task(pgrp, PIDTYPE_PGID);
1136 if (!g || task_session(g) != task_session(group_leader))
1137 goto out;
1138 }
1139
1140 err = security_task_setpgid(p, pgid);
1141 if (err)
1142 goto out;
1143
1144 if (task_pgrp(p) != pgrp)
1145 change_pid(p, PIDTYPE_PGID, pgrp);
1146
1147 err = 0;
1148 out:
1149 /* All paths lead to here, thus we are safe. -DaveM */
1150 write_unlock_irq(&tasklist_lock);
1151 rcu_read_unlock();
1152 return err;
1153 }
1154
do_getpgid(pid_t pid)1155 static int do_getpgid(pid_t pid)
1156 {
1157 struct task_struct *p;
1158 struct pid *grp;
1159 int retval;
1160
1161 rcu_read_lock();
1162 if (!pid)
1163 grp = task_pgrp(current);
1164 else {
1165 retval = -ESRCH;
1166 p = find_task_by_vpid(pid);
1167 if (!p)
1168 goto out;
1169 grp = task_pgrp(p);
1170 if (!grp)
1171 goto out;
1172
1173 retval = security_task_getpgid(p);
1174 if (retval)
1175 goto out;
1176 }
1177 retval = pid_vnr(grp);
1178 out:
1179 rcu_read_unlock();
1180 return retval;
1181 }
1182
SYSCALL_DEFINE1(getpgid,pid_t,pid)1183 SYSCALL_DEFINE1(getpgid, pid_t, pid)
1184 {
1185 return do_getpgid(pid);
1186 }
1187
1188 #ifdef __ARCH_WANT_SYS_GETPGRP
1189
SYSCALL_DEFINE0(getpgrp)1190 SYSCALL_DEFINE0(getpgrp)
1191 {
1192 return do_getpgid(0);
1193 }
1194
1195 #endif
1196
SYSCALL_DEFINE1(getsid,pid_t,pid)1197 SYSCALL_DEFINE1(getsid, pid_t, pid)
1198 {
1199 struct task_struct *p;
1200 struct pid *sid;
1201 int retval;
1202
1203 rcu_read_lock();
1204 if (!pid)
1205 sid = task_session(current);
1206 else {
1207 retval = -ESRCH;
1208 p = find_task_by_vpid(pid);
1209 if (!p)
1210 goto out;
1211 sid = task_session(p);
1212 if (!sid)
1213 goto out;
1214
1215 retval = security_task_getsid(p);
1216 if (retval)
1217 goto out;
1218 }
1219 retval = pid_vnr(sid);
1220 out:
1221 rcu_read_unlock();
1222 return retval;
1223 }
1224
set_special_pids(struct pid * pid)1225 static void set_special_pids(struct pid *pid)
1226 {
1227 struct task_struct *curr = current->group_leader;
1228
1229 if (task_session(curr) != pid)
1230 change_pid(curr, PIDTYPE_SID, pid);
1231
1232 if (task_pgrp(curr) != pid)
1233 change_pid(curr, PIDTYPE_PGID, pid);
1234 }
1235
ksys_setsid(void)1236 int ksys_setsid(void)
1237 {
1238 struct task_struct *group_leader = current->group_leader;
1239 struct pid *sid = task_pid(group_leader);
1240 pid_t session = pid_vnr(sid);
1241 int err = -EPERM;
1242
1243 write_lock_irq(&tasklist_lock);
1244 /* Fail if I am already a session leader */
1245 if (group_leader->signal->leader)
1246 goto out;
1247
1248 /* Fail if a process group id already exists that equals the
1249 * proposed session id.
1250 */
1251 if (pid_task(sid, PIDTYPE_PGID))
1252 goto out;
1253
1254 group_leader->signal->leader = 1;
1255 set_special_pids(sid);
1256
1257 proc_clear_tty(group_leader);
1258
1259 err = session;
1260 out:
1261 write_unlock_irq(&tasklist_lock);
1262 if (err > 0) {
1263 proc_sid_connector(group_leader);
1264 sched_autogroup_create_attach(group_leader);
1265 }
1266 return err;
1267 }
1268
SYSCALL_DEFINE0(setsid)1269 SYSCALL_DEFINE0(setsid)
1270 {
1271 return ksys_setsid();
1272 }
1273
1274 DECLARE_RWSEM(uts_sem);
1275
1276 #ifdef COMPAT_UTS_MACHINE
1277 #define override_architecture(name) \
1278 (personality(current->personality) == PER_LINUX32 && \
1279 copy_to_user(name->machine, COMPAT_UTS_MACHINE, \
1280 sizeof(COMPAT_UTS_MACHINE)))
1281 #else
1282 #define override_architecture(name) 0
1283 #endif
1284
1285 /*
1286 * Work around broken programs that cannot handle "Linux 3.0".
1287 * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40
1288 * And we map 4.x and later versions to 2.6.60+x, so 4.0/5.0/6.0/... would be
1289 * 2.6.60.
1290 */
override_release(char __user * release,size_t len)1291 static int override_release(char __user *release, size_t len)
1292 {
1293 int ret = 0;
1294
1295 if (current->personality & UNAME26) {
1296 const char *rest = UTS_RELEASE;
1297 char buf[65] = { 0 };
1298 int ndots = 0;
1299 unsigned v;
1300 size_t copy;
1301
1302 while (*rest) {
1303 if (*rest == '.' && ++ndots >= 3)
1304 break;
1305 if (!isdigit(*rest) && *rest != '.')
1306 break;
1307 rest++;
1308 }
1309 v = LINUX_VERSION_PATCHLEVEL + 60;
1310 copy = clamp_t(size_t, len, 1, sizeof(buf));
1311 copy = scnprintf(buf, copy, "2.6.%u%s", v, rest);
1312 ret = copy_to_user(release, buf, copy + 1);
1313 }
1314 return ret;
1315 }
1316
SYSCALL_DEFINE1(newuname,struct new_utsname __user *,name)1317 SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name)
1318 {
1319 struct new_utsname tmp;
1320
1321 down_read(&uts_sem);
1322 memcpy(&tmp, utsname(), sizeof(tmp));
1323 up_read(&uts_sem);
1324 if (copy_to_user(name, &tmp, sizeof(tmp)))
1325 return -EFAULT;
1326
1327 if (override_release(name->release, sizeof(name->release)))
1328 return -EFAULT;
1329 if (override_architecture(name))
1330 return -EFAULT;
1331 return 0;
1332 }
1333
1334 #ifdef __ARCH_WANT_SYS_OLD_UNAME
1335 /*
1336 * Old cruft
1337 */
SYSCALL_DEFINE1(uname,struct old_utsname __user *,name)1338 SYSCALL_DEFINE1(uname, struct old_utsname __user *, name)
1339 {
1340 struct old_utsname tmp;
1341
1342 if (!name)
1343 return -EFAULT;
1344
1345 down_read(&uts_sem);
1346 memcpy(&tmp, utsname(), sizeof(tmp));
1347 up_read(&uts_sem);
1348 if (copy_to_user(name, &tmp, sizeof(tmp)))
1349 return -EFAULT;
1350
1351 if (override_release(name->release, sizeof(name->release)))
1352 return -EFAULT;
1353 if (override_architecture(name))
1354 return -EFAULT;
1355 return 0;
1356 }
1357
SYSCALL_DEFINE1(olduname,struct oldold_utsname __user *,name)1358 SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name)
1359 {
1360 struct oldold_utsname tmp;
1361
1362 if (!name)
1363 return -EFAULT;
1364
1365 memset(&tmp, 0, sizeof(tmp));
1366
1367 down_read(&uts_sem);
1368 memcpy(&tmp.sysname, &utsname()->sysname, __OLD_UTS_LEN);
1369 memcpy(&tmp.nodename, &utsname()->nodename, __OLD_UTS_LEN);
1370 memcpy(&tmp.release, &utsname()->release, __OLD_UTS_LEN);
1371 memcpy(&tmp.version, &utsname()->version, __OLD_UTS_LEN);
1372 memcpy(&tmp.machine, &utsname()->machine, __OLD_UTS_LEN);
1373 up_read(&uts_sem);
1374 if (copy_to_user(name, &tmp, sizeof(tmp)))
1375 return -EFAULT;
1376
1377 if (override_architecture(name))
1378 return -EFAULT;
1379 if (override_release(name->release, sizeof(name->release)))
1380 return -EFAULT;
1381 return 0;
1382 }
1383 #endif
1384
SYSCALL_DEFINE2(sethostname,char __user *,name,int,len)1385 SYSCALL_DEFINE2(sethostname, char __user *, name, int, len)
1386 {
1387 int errno;
1388 char tmp[__NEW_UTS_LEN];
1389
1390 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1391 return -EPERM;
1392
1393 if (len < 0 || len > __NEW_UTS_LEN)
1394 return -EINVAL;
1395 errno = -EFAULT;
1396 if (!copy_from_user(tmp, name, len)) {
1397 struct new_utsname *u;
1398
1399 add_device_randomness(tmp, len);
1400 down_write(&uts_sem);
1401 u = utsname();
1402 memcpy(u->nodename, tmp, len);
1403 memset(u->nodename + len, 0, sizeof(u->nodename) - len);
1404 errno = 0;
1405 uts_proc_notify(UTS_PROC_HOSTNAME);
1406 up_write(&uts_sem);
1407 }
1408 return errno;
1409 }
1410
1411 #ifdef __ARCH_WANT_SYS_GETHOSTNAME
1412
SYSCALL_DEFINE2(gethostname,char __user *,name,int,len)1413 SYSCALL_DEFINE2(gethostname, char __user *, name, int, len)
1414 {
1415 int i;
1416 struct new_utsname *u;
1417 char tmp[__NEW_UTS_LEN + 1];
1418
1419 if (len < 0)
1420 return -EINVAL;
1421 down_read(&uts_sem);
1422 u = utsname();
1423 i = 1 + strlen(u->nodename);
1424 if (i > len)
1425 i = len;
1426 memcpy(tmp, u->nodename, i);
1427 up_read(&uts_sem);
1428 if (copy_to_user(name, tmp, i))
1429 return -EFAULT;
1430 return 0;
1431 }
1432
1433 #endif
1434
1435 /*
1436 * Only setdomainname; getdomainname can be implemented by calling
1437 * uname()
1438 */
SYSCALL_DEFINE2(setdomainname,char __user *,name,int,len)1439 SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len)
1440 {
1441 int errno;
1442 char tmp[__NEW_UTS_LEN];
1443
1444 if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN))
1445 return -EPERM;
1446 if (len < 0 || len > __NEW_UTS_LEN)
1447 return -EINVAL;
1448
1449 errno = -EFAULT;
1450 if (!copy_from_user(tmp, name, len)) {
1451 struct new_utsname *u;
1452
1453 add_device_randomness(tmp, len);
1454 down_write(&uts_sem);
1455 u = utsname();
1456 memcpy(u->domainname, tmp, len);
1457 memset(u->domainname + len, 0, sizeof(u->domainname) - len);
1458 errno = 0;
1459 uts_proc_notify(UTS_PROC_DOMAINNAME);
1460 up_write(&uts_sem);
1461 }
1462 return errno;
1463 }
1464
1465 /* make sure you are allowed to change @tsk limits before calling this */
do_prlimit(struct task_struct * tsk,unsigned int resource,struct rlimit * new_rlim,struct rlimit * old_rlim)1466 static int do_prlimit(struct task_struct *tsk, unsigned int resource,
1467 struct rlimit *new_rlim, struct rlimit *old_rlim)
1468 {
1469 struct rlimit *rlim;
1470 int retval = 0;
1471
1472 if (resource >= RLIM_NLIMITS)
1473 return -EINVAL;
1474 resource = array_index_nospec(resource, RLIM_NLIMITS);
1475
1476 if (new_rlim) {
1477 if (new_rlim->rlim_cur > new_rlim->rlim_max)
1478 return -EINVAL;
1479 if (resource == RLIMIT_NOFILE &&
1480 new_rlim->rlim_max > sysctl_nr_open)
1481 return -EPERM;
1482 }
1483
1484 /* Holding a refcount on tsk protects tsk->signal from disappearing. */
1485 rlim = tsk->signal->rlim + resource;
1486 task_lock(tsk->group_leader);
1487 if (new_rlim) {
1488 /*
1489 * Keep the capable check against init_user_ns until cgroups can
1490 * contain all limits.
1491 */
1492 if (new_rlim->rlim_max > rlim->rlim_max &&
1493 !capable(CAP_SYS_RESOURCE))
1494 retval = -EPERM;
1495 if (!retval)
1496 retval = security_task_setrlimit(tsk, resource, new_rlim);
1497 }
1498 if (!retval) {
1499 if (old_rlim)
1500 *old_rlim = *rlim;
1501 if (new_rlim)
1502 *rlim = *new_rlim;
1503 }
1504 task_unlock(tsk->group_leader);
1505
1506 /*
1507 * RLIMIT_CPU handling. Arm the posix CPU timer if the limit is not
1508 * infinite. In case of RLIM_INFINITY the posix CPU timer code
1509 * ignores the rlimit.
1510 */
1511 if (!retval && new_rlim && resource == RLIMIT_CPU &&
1512 new_rlim->rlim_cur != RLIM_INFINITY &&
1513 IS_ENABLED(CONFIG_POSIX_TIMERS)) {
1514 /*
1515 * update_rlimit_cpu can fail if the task is exiting, but there
1516 * may be other tasks in the thread group that are not exiting,
1517 * and they need their cpu timers adjusted.
1518 *
1519 * The group_leader is the last task to be released, so if we
1520 * cannot update_rlimit_cpu on it, then the entire process is
1521 * exiting and we do not need to update at all.
1522 */
1523 update_rlimit_cpu(tsk->group_leader, new_rlim->rlim_cur);
1524 }
1525
1526 return retval;
1527 }
1528
SYSCALL_DEFINE2(getrlimit,unsigned int,resource,struct rlimit __user *,rlim)1529 SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1530 {
1531 struct rlimit value;
1532 int ret;
1533
1534 ret = do_prlimit(current, resource, NULL, &value);
1535 if (!ret)
1536 ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0;
1537
1538 return ret;
1539 }
1540
1541 #ifdef CONFIG_COMPAT
1542
COMPAT_SYSCALL_DEFINE2(setrlimit,unsigned int,resource,struct compat_rlimit __user *,rlim)1543 COMPAT_SYSCALL_DEFINE2(setrlimit, unsigned int, resource,
1544 struct compat_rlimit __user *, rlim)
1545 {
1546 struct rlimit r;
1547 struct compat_rlimit r32;
1548
1549 if (copy_from_user(&r32, rlim, sizeof(struct compat_rlimit)))
1550 return -EFAULT;
1551
1552 if (r32.rlim_cur == COMPAT_RLIM_INFINITY)
1553 r.rlim_cur = RLIM_INFINITY;
1554 else
1555 r.rlim_cur = r32.rlim_cur;
1556 if (r32.rlim_max == COMPAT_RLIM_INFINITY)
1557 r.rlim_max = RLIM_INFINITY;
1558 else
1559 r.rlim_max = r32.rlim_max;
1560 return do_prlimit(current, resource, &r, NULL);
1561 }
1562
COMPAT_SYSCALL_DEFINE2(getrlimit,unsigned int,resource,struct compat_rlimit __user *,rlim)1563 COMPAT_SYSCALL_DEFINE2(getrlimit, unsigned int, resource,
1564 struct compat_rlimit __user *, rlim)
1565 {
1566 struct rlimit r;
1567 int ret;
1568
1569 ret = do_prlimit(current, resource, NULL, &r);
1570 if (!ret) {
1571 struct compat_rlimit r32;
1572 if (r.rlim_cur > COMPAT_RLIM_INFINITY)
1573 r32.rlim_cur = COMPAT_RLIM_INFINITY;
1574 else
1575 r32.rlim_cur = r.rlim_cur;
1576 if (r.rlim_max > COMPAT_RLIM_INFINITY)
1577 r32.rlim_max = COMPAT_RLIM_INFINITY;
1578 else
1579 r32.rlim_max = r.rlim_max;
1580
1581 if (copy_to_user(rlim, &r32, sizeof(struct compat_rlimit)))
1582 return -EFAULT;
1583 }
1584 return ret;
1585 }
1586
1587 #endif
1588
1589 #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT
1590
1591 /*
1592 * Back compatibility for getrlimit. Needed for some apps.
1593 */
SYSCALL_DEFINE2(old_getrlimit,unsigned int,resource,struct rlimit __user *,rlim)1594 SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1595 struct rlimit __user *, rlim)
1596 {
1597 struct rlimit x;
1598 if (resource >= RLIM_NLIMITS)
1599 return -EINVAL;
1600
1601 resource = array_index_nospec(resource, RLIM_NLIMITS);
1602 task_lock(current->group_leader);
1603 x = current->signal->rlim[resource];
1604 task_unlock(current->group_leader);
1605 if (x.rlim_cur > 0x7FFFFFFF)
1606 x.rlim_cur = 0x7FFFFFFF;
1607 if (x.rlim_max > 0x7FFFFFFF)
1608 x.rlim_max = 0x7FFFFFFF;
1609 return copy_to_user(rlim, &x, sizeof(x)) ? -EFAULT : 0;
1610 }
1611
1612 #ifdef CONFIG_COMPAT
COMPAT_SYSCALL_DEFINE2(old_getrlimit,unsigned int,resource,struct compat_rlimit __user *,rlim)1613 COMPAT_SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource,
1614 struct compat_rlimit __user *, rlim)
1615 {
1616 struct rlimit r;
1617
1618 if (resource >= RLIM_NLIMITS)
1619 return -EINVAL;
1620
1621 resource = array_index_nospec(resource, RLIM_NLIMITS);
1622 task_lock(current->group_leader);
1623 r = current->signal->rlim[resource];
1624 task_unlock(current->group_leader);
1625 if (r.rlim_cur > 0x7FFFFFFF)
1626 r.rlim_cur = 0x7FFFFFFF;
1627 if (r.rlim_max > 0x7FFFFFFF)
1628 r.rlim_max = 0x7FFFFFFF;
1629
1630 if (put_user(r.rlim_cur, &rlim->rlim_cur) ||
1631 put_user(r.rlim_max, &rlim->rlim_max))
1632 return -EFAULT;
1633 return 0;
1634 }
1635 #endif
1636
1637 #endif
1638
rlim64_is_infinity(__u64 rlim64)1639 static inline bool rlim64_is_infinity(__u64 rlim64)
1640 {
1641 #if BITS_PER_LONG < 64
1642 return rlim64 >= ULONG_MAX;
1643 #else
1644 return rlim64 == RLIM64_INFINITY;
1645 #endif
1646 }
1647
rlim_to_rlim64(const struct rlimit * rlim,struct rlimit64 * rlim64)1648 static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64)
1649 {
1650 if (rlim->rlim_cur == RLIM_INFINITY)
1651 rlim64->rlim_cur = RLIM64_INFINITY;
1652 else
1653 rlim64->rlim_cur = rlim->rlim_cur;
1654 if (rlim->rlim_max == RLIM_INFINITY)
1655 rlim64->rlim_max = RLIM64_INFINITY;
1656 else
1657 rlim64->rlim_max = rlim->rlim_max;
1658 }
1659
rlim64_to_rlim(const struct rlimit64 * rlim64,struct rlimit * rlim)1660 static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim)
1661 {
1662 if (rlim64_is_infinity(rlim64->rlim_cur))
1663 rlim->rlim_cur = RLIM_INFINITY;
1664 else
1665 rlim->rlim_cur = (unsigned long)rlim64->rlim_cur;
1666 if (rlim64_is_infinity(rlim64->rlim_max))
1667 rlim->rlim_max = RLIM_INFINITY;
1668 else
1669 rlim->rlim_max = (unsigned long)rlim64->rlim_max;
1670 }
1671
1672 /* rcu lock must be held */
check_prlimit_permission(struct task_struct * task,unsigned int flags)1673 static int check_prlimit_permission(struct task_struct *task,
1674 unsigned int flags)
1675 {
1676 const struct cred *cred = current_cred(), *tcred;
1677 bool id_match;
1678
1679 if (current == task)
1680 return 0;
1681
1682 tcred = __task_cred(task);
1683 id_match = (uid_eq(cred->uid, tcred->euid) &&
1684 uid_eq(cred->uid, tcred->suid) &&
1685 uid_eq(cred->uid, tcred->uid) &&
1686 gid_eq(cred->gid, tcred->egid) &&
1687 gid_eq(cred->gid, tcred->sgid) &&
1688 gid_eq(cred->gid, tcred->gid));
1689 if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE))
1690 return -EPERM;
1691
1692 return security_task_prlimit(cred, tcred, flags);
1693 }
1694
SYSCALL_DEFINE4(prlimit64,pid_t,pid,unsigned int,resource,const struct rlimit64 __user *,new_rlim,struct rlimit64 __user *,old_rlim)1695 SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource,
1696 const struct rlimit64 __user *, new_rlim,
1697 struct rlimit64 __user *, old_rlim)
1698 {
1699 struct rlimit64 old64, new64;
1700 struct rlimit old, new;
1701 struct task_struct *tsk;
1702 unsigned int checkflags = 0;
1703 int ret;
1704
1705 if (old_rlim)
1706 checkflags |= LSM_PRLIMIT_READ;
1707
1708 if (new_rlim) {
1709 if (copy_from_user(&new64, new_rlim, sizeof(new64)))
1710 return -EFAULT;
1711 rlim64_to_rlim(&new64, &new);
1712 checkflags |= LSM_PRLIMIT_WRITE;
1713 }
1714
1715 rcu_read_lock();
1716 tsk = pid ? find_task_by_vpid(pid) : current;
1717 if (!tsk) {
1718 rcu_read_unlock();
1719 return -ESRCH;
1720 }
1721 ret = check_prlimit_permission(tsk, checkflags);
1722 if (ret) {
1723 rcu_read_unlock();
1724 return ret;
1725 }
1726 get_task_struct(tsk);
1727 rcu_read_unlock();
1728
1729 ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL,
1730 old_rlim ? &old : NULL);
1731
1732 if (!ret && old_rlim) {
1733 rlim_to_rlim64(&old, &old64);
1734 if (copy_to_user(old_rlim, &old64, sizeof(old64)))
1735 ret = -EFAULT;
1736 }
1737
1738 put_task_struct(tsk);
1739 return ret;
1740 }
1741
SYSCALL_DEFINE2(setrlimit,unsigned int,resource,struct rlimit __user *,rlim)1742 SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim)
1743 {
1744 struct rlimit new_rlim;
1745
1746 if (copy_from_user(&new_rlim, rlim, sizeof(*rlim)))
1747 return -EFAULT;
1748 return do_prlimit(current, resource, &new_rlim, NULL);
1749 }
1750
1751 /*
1752 * It would make sense to put struct rusage in the task_struct,
1753 * except that would make the task_struct be *really big*. After
1754 * task_struct gets moved into malloc'ed memory, it would
1755 * make sense to do this. It will make moving the rest of the information
1756 * a lot simpler! (Which we're not doing right now because we're not
1757 * measuring them yet).
1758 *
1759 * When sampling multiple threads for RUSAGE_SELF, under SMP we might have
1760 * races with threads incrementing their own counters. But since word
1761 * reads are atomic, we either get new values or old values and we don't
1762 * care which for the sums. We always take the siglock to protect reading
1763 * the c* fields from p->signal from races with exit.c updating those
1764 * fields when reaping, so a sample either gets all the additions of a
1765 * given child after it's reaped, or none so this sample is before reaping.
1766 *
1767 * Locking:
1768 * We need to take the siglock for CHILDEREN, SELF and BOTH
1769 * for the cases current multithreaded, non-current single threaded
1770 * non-current multithreaded. Thread traversal is now safe with
1771 * the siglock held.
1772 * Strictly speaking, we donot need to take the siglock if we are current and
1773 * single threaded, as no one else can take our signal_struct away, no one
1774 * else can reap the children to update signal->c* counters, and no one else
1775 * can race with the signal-> fields. If we do not take any lock, the
1776 * signal-> fields could be read out of order while another thread was just
1777 * exiting. So we should place a read memory barrier when we avoid the lock.
1778 * On the writer side, write memory barrier is implied in __exit_signal
1779 * as __exit_signal releases the siglock spinlock after updating the signal->
1780 * fields. But we don't do this yet to keep things simple.
1781 *
1782 */
1783
accumulate_thread_rusage(struct task_struct * t,struct rusage * r)1784 static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r)
1785 {
1786 r->ru_nvcsw += t->nvcsw;
1787 r->ru_nivcsw += t->nivcsw;
1788 r->ru_minflt += t->min_flt;
1789 r->ru_majflt += t->maj_flt;
1790 r->ru_inblock += task_io_get_inblock(t);
1791 r->ru_oublock += task_io_get_oublock(t);
1792 }
1793
getrusage(struct task_struct * p,int who,struct rusage * r)1794 void getrusage(struct task_struct *p, int who, struct rusage *r)
1795 {
1796 struct task_struct *t;
1797 unsigned long flags;
1798 u64 tgutime, tgstime, utime, stime;
1799 unsigned long maxrss;
1800 struct mm_struct *mm;
1801 struct signal_struct *sig = p->signal;
1802 unsigned int seq = 0;
1803
1804 retry:
1805 memset(r, 0, sizeof(*r));
1806 utime = stime = 0;
1807 maxrss = 0;
1808
1809 if (who == RUSAGE_THREAD) {
1810 task_cputime_adjusted(current, &utime, &stime);
1811 accumulate_thread_rusage(p, r);
1812 maxrss = sig->maxrss;
1813 goto out_thread;
1814 }
1815
1816 flags = read_seqbegin_or_lock_irqsave(&sig->stats_lock, &seq);
1817
1818 switch (who) {
1819 case RUSAGE_BOTH:
1820 case RUSAGE_CHILDREN:
1821 utime = sig->cutime;
1822 stime = sig->cstime;
1823 r->ru_nvcsw = sig->cnvcsw;
1824 r->ru_nivcsw = sig->cnivcsw;
1825 r->ru_minflt = sig->cmin_flt;
1826 r->ru_majflt = sig->cmaj_flt;
1827 r->ru_inblock = sig->cinblock;
1828 r->ru_oublock = sig->coublock;
1829 maxrss = sig->cmaxrss;
1830
1831 if (who == RUSAGE_CHILDREN)
1832 break;
1833 fallthrough;
1834
1835 case RUSAGE_SELF:
1836 r->ru_nvcsw += sig->nvcsw;
1837 r->ru_nivcsw += sig->nivcsw;
1838 r->ru_minflt += sig->min_flt;
1839 r->ru_majflt += sig->maj_flt;
1840 r->ru_inblock += sig->inblock;
1841 r->ru_oublock += sig->oublock;
1842 if (maxrss < sig->maxrss)
1843 maxrss = sig->maxrss;
1844
1845 rcu_read_lock();
1846 __for_each_thread(sig, t)
1847 accumulate_thread_rusage(t, r);
1848 rcu_read_unlock();
1849
1850 break;
1851
1852 default:
1853 BUG();
1854 }
1855
1856 if (need_seqretry(&sig->stats_lock, seq)) {
1857 seq = 1;
1858 goto retry;
1859 }
1860 done_seqretry_irqrestore(&sig->stats_lock, seq, flags);
1861
1862 if (who == RUSAGE_CHILDREN)
1863 goto out_children;
1864
1865 thread_group_cputime_adjusted(p, &tgutime, &tgstime);
1866 utime += tgutime;
1867 stime += tgstime;
1868
1869 out_thread:
1870 mm = get_task_mm(p);
1871 if (mm) {
1872 setmax_mm_hiwater_rss(&maxrss, mm);
1873 mmput(mm);
1874 }
1875
1876 out_children:
1877 r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */
1878 r->ru_utime = ns_to_kernel_old_timeval(utime);
1879 r->ru_stime = ns_to_kernel_old_timeval(stime);
1880 }
1881
SYSCALL_DEFINE2(getrusage,int,who,struct rusage __user *,ru)1882 SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru)
1883 {
1884 struct rusage r;
1885
1886 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1887 who != RUSAGE_THREAD)
1888 return -EINVAL;
1889
1890 getrusage(current, who, &r);
1891 return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0;
1892 }
1893
1894 #ifdef CONFIG_COMPAT
COMPAT_SYSCALL_DEFINE2(getrusage,int,who,struct compat_rusage __user *,ru)1895 COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru)
1896 {
1897 struct rusage r;
1898
1899 if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN &&
1900 who != RUSAGE_THREAD)
1901 return -EINVAL;
1902
1903 getrusage(current, who, &r);
1904 return put_compat_rusage(&r, ru);
1905 }
1906 #endif
1907
SYSCALL_DEFINE1(umask,int,mask)1908 SYSCALL_DEFINE1(umask, int, mask)
1909 {
1910 mask = xchg(¤t->fs->umask, mask & S_IRWXUGO);
1911 return mask;
1912 }
1913
prctl_set_mm_exe_file(struct mm_struct * mm,unsigned int fd)1914 static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd)
1915 {
1916 CLASS(fd, exe)(fd);
1917 struct inode *inode;
1918 int err;
1919
1920 if (fd_empty(exe))
1921 return -EBADF;
1922
1923 inode = file_inode(fd_file(exe));
1924
1925 /*
1926 * Because the original mm->exe_file points to executable file, make
1927 * sure that this one is executable as well, to avoid breaking an
1928 * overall picture.
1929 */
1930 if (!S_ISREG(inode->i_mode) || path_noexec(&fd_file(exe)->f_path))
1931 return -EACCES;
1932
1933 err = file_permission(fd_file(exe), MAY_EXEC);
1934 if (err)
1935 return err;
1936
1937 return replace_mm_exe_file(mm, fd_file(exe));
1938 }
1939
1940 /*
1941 * Check arithmetic relations of passed addresses.
1942 *
1943 * WARNING: we don't require any capability here so be very careful
1944 * in what is allowed for modification from userspace.
1945 */
validate_prctl_map_addr(struct prctl_mm_map * prctl_map)1946 static int validate_prctl_map_addr(struct prctl_mm_map *prctl_map)
1947 {
1948 unsigned long mmap_max_addr = TASK_SIZE;
1949 int error = -EINVAL, i;
1950
1951 static const unsigned char offsets[] = {
1952 offsetof(struct prctl_mm_map, start_code),
1953 offsetof(struct prctl_mm_map, end_code),
1954 offsetof(struct prctl_mm_map, start_data),
1955 offsetof(struct prctl_mm_map, end_data),
1956 offsetof(struct prctl_mm_map, start_brk),
1957 offsetof(struct prctl_mm_map, brk),
1958 offsetof(struct prctl_mm_map, start_stack),
1959 offsetof(struct prctl_mm_map, arg_start),
1960 offsetof(struct prctl_mm_map, arg_end),
1961 offsetof(struct prctl_mm_map, env_start),
1962 offsetof(struct prctl_mm_map, env_end),
1963 };
1964
1965 /*
1966 * Make sure the members are not somewhere outside
1967 * of allowed address space.
1968 */
1969 for (i = 0; i < ARRAY_SIZE(offsets); i++) {
1970 u64 val = *(u64 *)((char *)prctl_map + offsets[i]);
1971
1972 if ((unsigned long)val >= mmap_max_addr ||
1973 (unsigned long)val < mmap_min_addr)
1974 goto out;
1975 }
1976
1977 /*
1978 * Make sure the pairs are ordered.
1979 */
1980 #define __prctl_check_order(__m1, __op, __m2) \
1981 ((unsigned long)prctl_map->__m1 __op \
1982 (unsigned long)prctl_map->__m2) ? 0 : -EINVAL
1983 error = __prctl_check_order(start_code, <, end_code);
1984 error |= __prctl_check_order(start_data,<=, end_data);
1985 error |= __prctl_check_order(start_brk, <=, brk);
1986 error |= __prctl_check_order(arg_start, <=, arg_end);
1987 error |= __prctl_check_order(env_start, <=, env_end);
1988 if (error)
1989 goto out;
1990 #undef __prctl_check_order
1991
1992 error = -EINVAL;
1993
1994 /*
1995 * Neither we should allow to override limits if they set.
1996 */
1997 if (check_data_rlimit(rlimit(RLIMIT_DATA), prctl_map->brk,
1998 prctl_map->start_brk, prctl_map->end_data,
1999 prctl_map->start_data))
2000 goto out;
2001
2002 error = 0;
2003 out:
2004 return error;
2005 }
2006
2007 #ifdef CONFIG_CHECKPOINT_RESTORE
prctl_set_mm_map(int opt,const void __user * addr,unsigned long data_size)2008 static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data_size)
2009 {
2010 struct prctl_mm_map prctl_map = { .exe_fd = (u32)-1, };
2011 unsigned long user_auxv[AT_VECTOR_SIZE];
2012 struct mm_struct *mm = current->mm;
2013 int error;
2014
2015 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2016 BUILD_BUG_ON(sizeof(struct prctl_mm_map) > 256);
2017
2018 if (opt == PR_SET_MM_MAP_SIZE)
2019 return put_user((unsigned int)sizeof(prctl_map),
2020 (unsigned int __user *)addr);
2021
2022 if (data_size != sizeof(prctl_map))
2023 return -EINVAL;
2024
2025 if (copy_from_user(&prctl_map, addr, sizeof(prctl_map)))
2026 return -EFAULT;
2027
2028 error = validate_prctl_map_addr(&prctl_map);
2029 if (error)
2030 return error;
2031
2032 if (prctl_map.auxv_size) {
2033 /*
2034 * Someone is trying to cheat the auxv vector.
2035 */
2036 if (!prctl_map.auxv ||
2037 prctl_map.auxv_size > sizeof(mm->saved_auxv))
2038 return -EINVAL;
2039
2040 memset(user_auxv, 0, sizeof(user_auxv));
2041 if (copy_from_user(user_auxv,
2042 (const void __user *)prctl_map.auxv,
2043 prctl_map.auxv_size))
2044 return -EFAULT;
2045
2046 /* Last entry must be AT_NULL as specification requires */
2047 user_auxv[AT_VECTOR_SIZE - 2] = AT_NULL;
2048 user_auxv[AT_VECTOR_SIZE - 1] = AT_NULL;
2049 }
2050
2051 if (prctl_map.exe_fd != (u32)-1) {
2052 /*
2053 * Check if the current user is checkpoint/restore capable.
2054 * At the time of this writing, it checks for CAP_SYS_ADMIN
2055 * or CAP_CHECKPOINT_RESTORE.
2056 * Note that a user with access to ptrace can masquerade an
2057 * arbitrary program as any executable, even setuid ones.
2058 * This may have implications in the tomoyo subsystem.
2059 */
2060 if (!checkpoint_restore_ns_capable(current_user_ns()))
2061 return -EPERM;
2062
2063 error = prctl_set_mm_exe_file(mm, prctl_map.exe_fd);
2064 if (error)
2065 return error;
2066 }
2067
2068 /*
2069 * arg_lock protects concurrent updates but we still need mmap_lock for
2070 * read to exclude races with sys_brk.
2071 */
2072 mmap_read_lock(mm);
2073
2074 /*
2075 * We don't validate if these members are pointing to
2076 * real present VMAs because application may have correspond
2077 * VMAs already unmapped and kernel uses these members for statistics
2078 * output in procfs mostly, except
2079 *
2080 * - @start_brk/@brk which are used in do_brk_flags but kernel lookups
2081 * for VMAs when updating these members so anything wrong written
2082 * here cause kernel to swear at userspace program but won't lead
2083 * to any problem in kernel itself
2084 */
2085
2086 spin_lock(&mm->arg_lock);
2087 mm->start_code = prctl_map.start_code;
2088 mm->end_code = prctl_map.end_code;
2089 mm->start_data = prctl_map.start_data;
2090 mm->end_data = prctl_map.end_data;
2091 mm->start_brk = prctl_map.start_brk;
2092 mm->brk = prctl_map.brk;
2093 mm->start_stack = prctl_map.start_stack;
2094 mm->arg_start = prctl_map.arg_start;
2095 mm->arg_end = prctl_map.arg_end;
2096 mm->env_start = prctl_map.env_start;
2097 mm->env_end = prctl_map.env_end;
2098 spin_unlock(&mm->arg_lock);
2099
2100 /*
2101 * Note this update of @saved_auxv is lockless thus
2102 * if someone reads this member in procfs while we're
2103 * updating -- it may get partly updated results. It's
2104 * known and acceptable trade off: we leave it as is to
2105 * not introduce additional locks here making the kernel
2106 * more complex.
2107 */
2108 if (prctl_map.auxv_size)
2109 memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv));
2110
2111 mmap_read_unlock(mm);
2112 return 0;
2113 }
2114 #endif /* CONFIG_CHECKPOINT_RESTORE */
2115
prctl_set_auxv(struct mm_struct * mm,unsigned long addr,unsigned long len)2116 static int prctl_set_auxv(struct mm_struct *mm, unsigned long addr,
2117 unsigned long len)
2118 {
2119 /*
2120 * This doesn't move the auxiliary vector itself since it's pinned to
2121 * mm_struct, but it permits filling the vector with new values. It's
2122 * up to the caller to provide sane values here, otherwise userspace
2123 * tools which use this vector might be unhappy.
2124 */
2125 unsigned long user_auxv[AT_VECTOR_SIZE] = {};
2126
2127 if (len > sizeof(user_auxv))
2128 return -EINVAL;
2129
2130 if (copy_from_user(user_auxv, (const void __user *)addr, len))
2131 return -EFAULT;
2132
2133 /* Make sure the last entry is always AT_NULL */
2134 user_auxv[AT_VECTOR_SIZE - 2] = 0;
2135 user_auxv[AT_VECTOR_SIZE - 1] = 0;
2136
2137 BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv));
2138
2139 task_lock(current);
2140 memcpy(mm->saved_auxv, user_auxv, len);
2141 task_unlock(current);
2142
2143 return 0;
2144 }
2145
prctl_set_mm(int opt,unsigned long addr,unsigned long arg4,unsigned long arg5)2146 static int prctl_set_mm(int opt, unsigned long addr,
2147 unsigned long arg4, unsigned long arg5)
2148 {
2149 struct mm_struct *mm = current->mm;
2150 struct prctl_mm_map prctl_map = {
2151 .auxv = NULL,
2152 .auxv_size = 0,
2153 .exe_fd = -1,
2154 };
2155 struct vm_area_struct *vma;
2156 int error;
2157
2158 if (arg5 || (arg4 && (opt != PR_SET_MM_AUXV &&
2159 opt != PR_SET_MM_MAP &&
2160 opt != PR_SET_MM_MAP_SIZE)))
2161 return -EINVAL;
2162
2163 #ifdef CONFIG_CHECKPOINT_RESTORE
2164 if (opt == PR_SET_MM_MAP || opt == PR_SET_MM_MAP_SIZE)
2165 return prctl_set_mm_map(opt, (const void __user *)addr, arg4);
2166 #endif
2167
2168 if (!capable(CAP_SYS_RESOURCE))
2169 return -EPERM;
2170
2171 if (opt == PR_SET_MM_EXE_FILE)
2172 return prctl_set_mm_exe_file(mm, (unsigned int)addr);
2173
2174 if (opt == PR_SET_MM_AUXV)
2175 return prctl_set_auxv(mm, addr, arg4);
2176
2177 if (addr >= TASK_SIZE || addr < mmap_min_addr)
2178 return -EINVAL;
2179
2180 error = -EINVAL;
2181
2182 /*
2183 * arg_lock protects concurrent updates of arg boundaries, we need
2184 * mmap_lock for a) concurrent sys_brk, b) finding VMA for addr
2185 * validation.
2186 */
2187 mmap_read_lock(mm);
2188 vma = find_vma(mm, addr);
2189
2190 spin_lock(&mm->arg_lock);
2191 prctl_map.start_code = mm->start_code;
2192 prctl_map.end_code = mm->end_code;
2193 prctl_map.start_data = mm->start_data;
2194 prctl_map.end_data = mm->end_data;
2195 prctl_map.start_brk = mm->start_brk;
2196 prctl_map.brk = mm->brk;
2197 prctl_map.start_stack = mm->start_stack;
2198 prctl_map.arg_start = mm->arg_start;
2199 prctl_map.arg_end = mm->arg_end;
2200 prctl_map.env_start = mm->env_start;
2201 prctl_map.env_end = mm->env_end;
2202
2203 switch (opt) {
2204 case PR_SET_MM_START_CODE:
2205 prctl_map.start_code = addr;
2206 break;
2207 case PR_SET_MM_END_CODE:
2208 prctl_map.end_code = addr;
2209 break;
2210 case PR_SET_MM_START_DATA:
2211 prctl_map.start_data = addr;
2212 break;
2213 case PR_SET_MM_END_DATA:
2214 prctl_map.end_data = addr;
2215 break;
2216 case PR_SET_MM_START_STACK:
2217 prctl_map.start_stack = addr;
2218 break;
2219 case PR_SET_MM_START_BRK:
2220 prctl_map.start_brk = addr;
2221 break;
2222 case PR_SET_MM_BRK:
2223 prctl_map.brk = addr;
2224 break;
2225 case PR_SET_MM_ARG_START:
2226 prctl_map.arg_start = addr;
2227 break;
2228 case PR_SET_MM_ARG_END:
2229 prctl_map.arg_end = addr;
2230 break;
2231 case PR_SET_MM_ENV_START:
2232 prctl_map.env_start = addr;
2233 break;
2234 case PR_SET_MM_ENV_END:
2235 prctl_map.env_end = addr;
2236 break;
2237 default:
2238 goto out;
2239 }
2240
2241 error = validate_prctl_map_addr(&prctl_map);
2242 if (error)
2243 goto out;
2244
2245 switch (opt) {
2246 /*
2247 * If command line arguments and environment
2248 * are placed somewhere else on stack, we can
2249 * set them up here, ARG_START/END to setup
2250 * command line arguments and ENV_START/END
2251 * for environment.
2252 */
2253 case PR_SET_MM_START_STACK:
2254 case PR_SET_MM_ARG_START:
2255 case PR_SET_MM_ARG_END:
2256 case PR_SET_MM_ENV_START:
2257 case PR_SET_MM_ENV_END:
2258 if (!vma) {
2259 error = -EFAULT;
2260 goto out;
2261 }
2262 }
2263
2264 mm->start_code = prctl_map.start_code;
2265 mm->end_code = prctl_map.end_code;
2266 mm->start_data = prctl_map.start_data;
2267 mm->end_data = prctl_map.end_data;
2268 mm->start_brk = prctl_map.start_brk;
2269 mm->brk = prctl_map.brk;
2270 mm->start_stack = prctl_map.start_stack;
2271 mm->arg_start = prctl_map.arg_start;
2272 mm->arg_end = prctl_map.arg_end;
2273 mm->env_start = prctl_map.env_start;
2274 mm->env_end = prctl_map.env_end;
2275
2276 error = 0;
2277 out:
2278 spin_unlock(&mm->arg_lock);
2279 mmap_read_unlock(mm);
2280 return error;
2281 }
2282
2283 #ifdef CONFIG_CHECKPOINT_RESTORE
prctl_get_tid_address(struct task_struct * me,int __user * __user * tid_addr)2284 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2285 {
2286 return put_user(me->clear_child_tid, tid_addr);
2287 }
2288 #else
prctl_get_tid_address(struct task_struct * me,int __user * __user * tid_addr)2289 static int prctl_get_tid_address(struct task_struct *me, int __user * __user *tid_addr)
2290 {
2291 return -EINVAL;
2292 }
2293 #endif
2294
propagate_has_child_subreaper(struct task_struct * p,void * data)2295 static int propagate_has_child_subreaper(struct task_struct *p, void *data)
2296 {
2297 /*
2298 * If task has has_child_subreaper - all its descendants
2299 * already have these flag too and new descendants will
2300 * inherit it on fork, skip them.
2301 *
2302 * If we've found child_reaper - skip descendants in
2303 * it's subtree as they will never get out pidns.
2304 */
2305 if (p->signal->has_child_subreaper ||
2306 is_child_reaper(task_pid(p)))
2307 return 0;
2308
2309 p->signal->has_child_subreaper = 1;
2310 return 1;
2311 }
2312
arch_prctl_spec_ctrl_get(struct task_struct * t,unsigned long which)2313 int __weak arch_prctl_spec_ctrl_get(struct task_struct *t, unsigned long which)
2314 {
2315 return -EINVAL;
2316 }
2317
arch_prctl_spec_ctrl_set(struct task_struct * t,unsigned long which,unsigned long ctrl)2318 int __weak arch_prctl_spec_ctrl_set(struct task_struct *t, unsigned long which,
2319 unsigned long ctrl)
2320 {
2321 return -EINVAL;
2322 }
2323
arch_get_shadow_stack_status(struct task_struct * t,unsigned long __user * status)2324 int __weak arch_get_shadow_stack_status(struct task_struct *t, unsigned long __user *status)
2325 {
2326 return -EINVAL;
2327 }
2328
arch_set_shadow_stack_status(struct task_struct * t,unsigned long status)2329 int __weak arch_set_shadow_stack_status(struct task_struct *t, unsigned long status)
2330 {
2331 return -EINVAL;
2332 }
2333
arch_lock_shadow_stack_status(struct task_struct * t,unsigned long status)2334 int __weak arch_lock_shadow_stack_status(struct task_struct *t, unsigned long status)
2335 {
2336 return -EINVAL;
2337 }
2338
2339 #define PR_IO_FLUSHER (PF_MEMALLOC_NOIO | PF_LOCAL_THROTTLE)
2340
2341 #ifdef CONFIG_ANON_VMA_NAME
2342
2343 #define ANON_VMA_NAME_MAX_LEN 80
2344 #define ANON_VMA_NAME_INVALID_CHARS "\\`$[]"
2345
is_valid_name_char(char ch)2346 static inline bool is_valid_name_char(char ch)
2347 {
2348 /* printable ascii characters, excluding ANON_VMA_NAME_INVALID_CHARS */
2349 return ch > 0x1f && ch < 0x7f &&
2350 !strchr(ANON_VMA_NAME_INVALID_CHARS, ch);
2351 }
2352
prctl_set_vma(unsigned long opt,unsigned long addr,unsigned long size,unsigned long arg)2353 static int prctl_set_vma(unsigned long opt, unsigned long addr,
2354 unsigned long size, unsigned long arg)
2355 {
2356 struct mm_struct *mm = current->mm;
2357 const char __user *uname;
2358 struct anon_vma_name *anon_name = NULL;
2359 int error;
2360
2361 switch (opt) {
2362 case PR_SET_VMA_ANON_NAME:
2363 uname = (const char __user *)arg;
2364 if (uname) {
2365 char *name, *pch;
2366
2367 name = strndup_user(uname, ANON_VMA_NAME_MAX_LEN);
2368 if (IS_ERR(name))
2369 return PTR_ERR(name);
2370
2371 for (pch = name; *pch != '\0'; pch++) {
2372 if (!is_valid_name_char(*pch)) {
2373 kfree(name);
2374 return -EINVAL;
2375 }
2376 }
2377 /* anon_vma has its own copy */
2378 anon_name = anon_vma_name_alloc(name);
2379 kfree(name);
2380 if (!anon_name)
2381 return -ENOMEM;
2382
2383 }
2384
2385 mmap_write_lock(mm);
2386 error = madvise_set_anon_name(mm, addr, size, anon_name);
2387 mmap_write_unlock(mm);
2388 anon_vma_name_put(anon_name);
2389 break;
2390 default:
2391 error = -EINVAL;
2392 }
2393
2394 return error;
2395 }
2396
2397 #else /* CONFIG_ANON_VMA_NAME */
prctl_set_vma(unsigned long opt,unsigned long start,unsigned long size,unsigned long arg)2398 static int prctl_set_vma(unsigned long opt, unsigned long start,
2399 unsigned long size, unsigned long arg)
2400 {
2401 return -EINVAL;
2402 }
2403 #endif /* CONFIG_ANON_VMA_NAME */
2404
get_current_mdwe(void)2405 static inline unsigned long get_current_mdwe(void)
2406 {
2407 unsigned long ret = 0;
2408
2409 if (test_bit(MMF_HAS_MDWE, ¤t->mm->flags))
2410 ret |= PR_MDWE_REFUSE_EXEC_GAIN;
2411 if (test_bit(MMF_HAS_MDWE_NO_INHERIT, ¤t->mm->flags))
2412 ret |= PR_MDWE_NO_INHERIT;
2413
2414 return ret;
2415 }
2416
prctl_set_mdwe(unsigned long bits,unsigned long arg3,unsigned long arg4,unsigned long arg5)2417 static inline int prctl_set_mdwe(unsigned long bits, unsigned long arg3,
2418 unsigned long arg4, unsigned long arg5)
2419 {
2420 unsigned long current_bits;
2421
2422 if (arg3 || arg4 || arg5)
2423 return -EINVAL;
2424
2425 if (bits & ~(PR_MDWE_REFUSE_EXEC_GAIN | PR_MDWE_NO_INHERIT))
2426 return -EINVAL;
2427
2428 /* NO_INHERIT only makes sense with REFUSE_EXEC_GAIN */
2429 if (bits & PR_MDWE_NO_INHERIT && !(bits & PR_MDWE_REFUSE_EXEC_GAIN))
2430 return -EINVAL;
2431
2432 /*
2433 * EOPNOTSUPP might be more appropriate here in principle, but
2434 * existing userspace depends on EINVAL specifically.
2435 */
2436 if (!arch_memory_deny_write_exec_supported())
2437 return -EINVAL;
2438
2439 current_bits = get_current_mdwe();
2440 if (current_bits && current_bits != bits)
2441 return -EPERM; /* Cannot unset the flags */
2442
2443 if (bits & PR_MDWE_NO_INHERIT)
2444 set_bit(MMF_HAS_MDWE_NO_INHERIT, ¤t->mm->flags);
2445 if (bits & PR_MDWE_REFUSE_EXEC_GAIN)
2446 set_bit(MMF_HAS_MDWE, ¤t->mm->flags);
2447
2448 return 0;
2449 }
2450
prctl_get_mdwe(unsigned long arg2,unsigned long arg3,unsigned long arg4,unsigned long arg5)2451 static inline int prctl_get_mdwe(unsigned long arg2, unsigned long arg3,
2452 unsigned long arg4, unsigned long arg5)
2453 {
2454 if (arg2 || arg3 || arg4 || arg5)
2455 return -EINVAL;
2456 return get_current_mdwe();
2457 }
2458
prctl_get_auxv(void __user * addr,unsigned long len)2459 static int prctl_get_auxv(void __user *addr, unsigned long len)
2460 {
2461 struct mm_struct *mm = current->mm;
2462 unsigned long size = min_t(unsigned long, sizeof(mm->saved_auxv), len);
2463
2464 if (size && copy_to_user(addr, mm->saved_auxv, size))
2465 return -EFAULT;
2466 return sizeof(mm->saved_auxv);
2467 }
2468
SYSCALL_DEFINE5(prctl,int,option,unsigned long,arg2,unsigned long,arg3,unsigned long,arg4,unsigned long,arg5)2469 SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
2470 unsigned long, arg4, unsigned long, arg5)
2471 {
2472 struct task_struct *me = current;
2473 unsigned char comm[sizeof(me->comm)];
2474 long error;
2475
2476 error = security_task_prctl(option, arg2, arg3, arg4, arg5);
2477 if (error != -ENOSYS)
2478 return error;
2479
2480 error = 0;
2481 switch (option) {
2482 case PR_SET_PDEATHSIG:
2483 if (!valid_signal(arg2)) {
2484 error = -EINVAL;
2485 break;
2486 }
2487 me->pdeath_signal = arg2;
2488 break;
2489 case PR_GET_PDEATHSIG:
2490 error = put_user(me->pdeath_signal, (int __user *)arg2);
2491 break;
2492 case PR_GET_DUMPABLE:
2493 error = get_dumpable(me->mm);
2494 break;
2495 case PR_SET_DUMPABLE:
2496 if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) {
2497 error = -EINVAL;
2498 break;
2499 }
2500 set_dumpable(me->mm, arg2);
2501 break;
2502
2503 case PR_SET_UNALIGN:
2504 error = SET_UNALIGN_CTL(me, arg2);
2505 break;
2506 case PR_GET_UNALIGN:
2507 error = GET_UNALIGN_CTL(me, arg2);
2508 break;
2509 case PR_SET_FPEMU:
2510 error = SET_FPEMU_CTL(me, arg2);
2511 break;
2512 case PR_GET_FPEMU:
2513 error = GET_FPEMU_CTL(me, arg2);
2514 break;
2515 case PR_SET_FPEXC:
2516 error = SET_FPEXC_CTL(me, arg2);
2517 break;
2518 case PR_GET_FPEXC:
2519 error = GET_FPEXC_CTL(me, arg2);
2520 break;
2521 case PR_GET_TIMING:
2522 error = PR_TIMING_STATISTICAL;
2523 break;
2524 case PR_SET_TIMING:
2525 if (arg2 != PR_TIMING_STATISTICAL)
2526 error = -EINVAL;
2527 break;
2528 case PR_SET_NAME:
2529 comm[sizeof(me->comm) - 1] = 0;
2530 if (strncpy_from_user(comm, (char __user *)arg2,
2531 sizeof(me->comm) - 1) < 0)
2532 return -EFAULT;
2533 set_task_comm(me, comm);
2534 proc_comm_connector(me);
2535 break;
2536 case PR_GET_NAME:
2537 get_task_comm(comm, me);
2538 if (copy_to_user((char __user *)arg2, comm, sizeof(comm)))
2539 return -EFAULT;
2540 break;
2541 case PR_GET_ENDIAN:
2542 error = GET_ENDIAN(me, arg2);
2543 break;
2544 case PR_SET_ENDIAN:
2545 error = SET_ENDIAN(me, arg2);
2546 break;
2547 case PR_GET_SECCOMP:
2548 error = prctl_get_seccomp();
2549 break;
2550 case PR_SET_SECCOMP:
2551 error = prctl_set_seccomp(arg2, (char __user *)arg3);
2552 break;
2553 case PR_GET_TSC:
2554 error = GET_TSC_CTL(arg2);
2555 break;
2556 case PR_SET_TSC:
2557 error = SET_TSC_CTL(arg2);
2558 break;
2559 case PR_TASK_PERF_EVENTS_DISABLE:
2560 error = perf_event_task_disable();
2561 break;
2562 case PR_TASK_PERF_EVENTS_ENABLE:
2563 error = perf_event_task_enable();
2564 break;
2565 case PR_GET_TIMERSLACK:
2566 if (current->timer_slack_ns > ULONG_MAX)
2567 error = ULONG_MAX;
2568 else
2569 error = current->timer_slack_ns;
2570 break;
2571 case PR_SET_TIMERSLACK:
2572 if (rt_or_dl_task_policy(current))
2573 break;
2574 if (arg2 <= 0)
2575 current->timer_slack_ns =
2576 current->default_timer_slack_ns;
2577 else
2578 current->timer_slack_ns = arg2;
2579 break;
2580 case PR_MCE_KILL:
2581 if (arg4 | arg5)
2582 return -EINVAL;
2583 switch (arg2) {
2584 case PR_MCE_KILL_CLEAR:
2585 if (arg3 != 0)
2586 return -EINVAL;
2587 current->flags &= ~PF_MCE_PROCESS;
2588 break;
2589 case PR_MCE_KILL_SET:
2590 current->flags |= PF_MCE_PROCESS;
2591 if (arg3 == PR_MCE_KILL_EARLY)
2592 current->flags |= PF_MCE_EARLY;
2593 else if (arg3 == PR_MCE_KILL_LATE)
2594 current->flags &= ~PF_MCE_EARLY;
2595 else if (arg3 == PR_MCE_KILL_DEFAULT)
2596 current->flags &=
2597 ~(PF_MCE_EARLY|PF_MCE_PROCESS);
2598 else
2599 return -EINVAL;
2600 break;
2601 default:
2602 return -EINVAL;
2603 }
2604 break;
2605 case PR_MCE_KILL_GET:
2606 if (arg2 | arg3 | arg4 | arg5)
2607 return -EINVAL;
2608 if (current->flags & PF_MCE_PROCESS)
2609 error = (current->flags & PF_MCE_EARLY) ?
2610 PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE;
2611 else
2612 error = PR_MCE_KILL_DEFAULT;
2613 break;
2614 case PR_SET_MM:
2615 error = prctl_set_mm(arg2, arg3, arg4, arg5);
2616 break;
2617 case PR_GET_TID_ADDRESS:
2618 error = prctl_get_tid_address(me, (int __user * __user *)arg2);
2619 break;
2620 case PR_SET_CHILD_SUBREAPER:
2621 me->signal->is_child_subreaper = !!arg2;
2622 if (!arg2)
2623 break;
2624
2625 walk_process_tree(me, propagate_has_child_subreaper, NULL);
2626 break;
2627 case PR_GET_CHILD_SUBREAPER:
2628 error = put_user(me->signal->is_child_subreaper,
2629 (int __user *)arg2);
2630 break;
2631 case PR_SET_NO_NEW_PRIVS:
2632 if (arg2 != 1 || arg3 || arg4 || arg5)
2633 return -EINVAL;
2634
2635 task_set_no_new_privs(current);
2636 break;
2637 case PR_GET_NO_NEW_PRIVS:
2638 if (arg2 || arg3 || arg4 || arg5)
2639 return -EINVAL;
2640 return task_no_new_privs(current) ? 1 : 0;
2641 case PR_GET_THP_DISABLE:
2642 if (arg2 || arg3 || arg4 || arg5)
2643 return -EINVAL;
2644 error = !!test_bit(MMF_DISABLE_THP, &me->mm->flags);
2645 break;
2646 case PR_SET_THP_DISABLE:
2647 if (arg3 || arg4 || arg5)
2648 return -EINVAL;
2649 if (mmap_write_lock_killable(me->mm))
2650 return -EINTR;
2651 if (arg2)
2652 set_bit(MMF_DISABLE_THP, &me->mm->flags);
2653 else
2654 clear_bit(MMF_DISABLE_THP, &me->mm->flags);
2655 mmap_write_unlock(me->mm);
2656 break;
2657 case PR_MPX_ENABLE_MANAGEMENT:
2658 case PR_MPX_DISABLE_MANAGEMENT:
2659 /* No longer implemented: */
2660 return -EINVAL;
2661 case PR_SET_FP_MODE:
2662 error = SET_FP_MODE(me, arg2);
2663 break;
2664 case PR_GET_FP_MODE:
2665 error = GET_FP_MODE(me);
2666 break;
2667 case PR_SVE_SET_VL:
2668 error = SVE_SET_VL(arg2);
2669 break;
2670 case PR_SVE_GET_VL:
2671 error = SVE_GET_VL();
2672 break;
2673 case PR_SME_SET_VL:
2674 error = SME_SET_VL(arg2);
2675 break;
2676 case PR_SME_GET_VL:
2677 error = SME_GET_VL();
2678 break;
2679 case PR_GET_SPECULATION_CTRL:
2680 if (arg3 || arg4 || arg5)
2681 return -EINVAL;
2682 error = arch_prctl_spec_ctrl_get(me, arg2);
2683 break;
2684 case PR_SET_SPECULATION_CTRL:
2685 if (arg4 || arg5)
2686 return -EINVAL;
2687 error = arch_prctl_spec_ctrl_set(me, arg2, arg3);
2688 break;
2689 case PR_PAC_RESET_KEYS:
2690 if (arg3 || arg4 || arg5)
2691 return -EINVAL;
2692 error = PAC_RESET_KEYS(me, arg2);
2693 break;
2694 case PR_PAC_SET_ENABLED_KEYS:
2695 if (arg4 || arg5)
2696 return -EINVAL;
2697 error = PAC_SET_ENABLED_KEYS(me, arg2, arg3);
2698 break;
2699 case PR_PAC_GET_ENABLED_KEYS:
2700 if (arg2 || arg3 || arg4 || arg5)
2701 return -EINVAL;
2702 error = PAC_GET_ENABLED_KEYS(me);
2703 break;
2704 case PR_SET_TAGGED_ADDR_CTRL:
2705 if (arg3 || arg4 || arg5)
2706 return -EINVAL;
2707 error = SET_TAGGED_ADDR_CTRL(arg2);
2708 break;
2709 case PR_GET_TAGGED_ADDR_CTRL:
2710 if (arg2 || arg3 || arg4 || arg5)
2711 return -EINVAL;
2712 error = GET_TAGGED_ADDR_CTRL();
2713 break;
2714 case PR_SET_IO_FLUSHER:
2715 if (!capable(CAP_SYS_RESOURCE))
2716 return -EPERM;
2717
2718 if (arg3 || arg4 || arg5)
2719 return -EINVAL;
2720
2721 if (arg2 == 1)
2722 current->flags |= PR_IO_FLUSHER;
2723 else if (!arg2)
2724 current->flags &= ~PR_IO_FLUSHER;
2725 else
2726 return -EINVAL;
2727 break;
2728 case PR_GET_IO_FLUSHER:
2729 if (!capable(CAP_SYS_RESOURCE))
2730 return -EPERM;
2731
2732 if (arg2 || arg3 || arg4 || arg5)
2733 return -EINVAL;
2734
2735 error = (current->flags & PR_IO_FLUSHER) == PR_IO_FLUSHER;
2736 break;
2737 case PR_SET_SYSCALL_USER_DISPATCH:
2738 error = set_syscall_user_dispatch(arg2, arg3, arg4,
2739 (char __user *) arg5);
2740 break;
2741 #ifdef CONFIG_SCHED_CORE
2742 case PR_SCHED_CORE:
2743 error = sched_core_share_pid(arg2, arg3, arg4, arg5);
2744 break;
2745 #endif
2746 case PR_SET_MDWE:
2747 error = prctl_set_mdwe(arg2, arg3, arg4, arg5);
2748 break;
2749 case PR_GET_MDWE:
2750 error = prctl_get_mdwe(arg2, arg3, arg4, arg5);
2751 break;
2752 case PR_PPC_GET_DEXCR:
2753 if (arg3 || arg4 || arg5)
2754 return -EINVAL;
2755 error = PPC_GET_DEXCR_ASPECT(me, arg2);
2756 break;
2757 case PR_PPC_SET_DEXCR:
2758 if (arg4 || arg5)
2759 return -EINVAL;
2760 error = PPC_SET_DEXCR_ASPECT(me, arg2, arg3);
2761 break;
2762 case PR_SET_VMA:
2763 error = prctl_set_vma(arg2, arg3, arg4, arg5);
2764 break;
2765 case PR_GET_AUXV:
2766 if (arg4 || arg5)
2767 return -EINVAL;
2768 error = prctl_get_auxv((void __user *)arg2, arg3);
2769 break;
2770 #ifdef CONFIG_KSM
2771 case PR_SET_MEMORY_MERGE:
2772 if (arg3 || arg4 || arg5)
2773 return -EINVAL;
2774 if (mmap_write_lock_killable(me->mm))
2775 return -EINTR;
2776
2777 if (arg2)
2778 error = ksm_enable_merge_any(me->mm);
2779 else
2780 error = ksm_disable_merge_any(me->mm);
2781 mmap_write_unlock(me->mm);
2782 break;
2783 case PR_GET_MEMORY_MERGE:
2784 if (arg2 || arg3 || arg4 || arg5)
2785 return -EINVAL;
2786
2787 error = !!test_bit(MMF_VM_MERGE_ANY, &me->mm->flags);
2788 break;
2789 #endif
2790 case PR_RISCV_V_SET_CONTROL:
2791 error = RISCV_V_SET_CONTROL(arg2);
2792 break;
2793 case PR_RISCV_V_GET_CONTROL:
2794 error = RISCV_V_GET_CONTROL();
2795 break;
2796 case PR_RISCV_SET_ICACHE_FLUSH_CTX:
2797 error = RISCV_SET_ICACHE_FLUSH_CTX(arg2, arg3);
2798 break;
2799 case PR_GET_SHADOW_STACK_STATUS:
2800 if (arg3 || arg4 || arg5)
2801 return -EINVAL;
2802 error = arch_get_shadow_stack_status(me, (unsigned long __user *) arg2);
2803 break;
2804 case PR_SET_SHADOW_STACK_STATUS:
2805 if (arg3 || arg4 || arg5)
2806 return -EINVAL;
2807 error = arch_set_shadow_stack_status(me, arg2);
2808 break;
2809 case PR_LOCK_SHADOW_STACK_STATUS:
2810 if (arg3 || arg4 || arg5)
2811 return -EINVAL;
2812 error = arch_lock_shadow_stack_status(me, arg2);
2813 break;
2814 default:
2815 trace_task_prctl_unknown(option, arg2, arg3, arg4, arg5);
2816 error = -EINVAL;
2817 break;
2818 }
2819 return error;
2820 }
2821
SYSCALL_DEFINE3(getcpu,unsigned __user *,cpup,unsigned __user *,nodep,struct getcpu_cache __user *,unused)2822 SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep,
2823 struct getcpu_cache __user *, unused)
2824 {
2825 int err = 0;
2826 int cpu = raw_smp_processor_id();
2827
2828 if (cpup)
2829 err |= put_user(cpu, cpup);
2830 if (nodep)
2831 err |= put_user(cpu_to_node(cpu), nodep);
2832 return err ? -EFAULT : 0;
2833 }
2834
2835 /**
2836 * do_sysinfo - fill in sysinfo struct
2837 * @info: pointer to buffer to fill
2838 */
do_sysinfo(struct sysinfo * info)2839 static int do_sysinfo(struct sysinfo *info)
2840 {
2841 unsigned long mem_total, sav_total;
2842 unsigned int mem_unit, bitcount;
2843 struct timespec64 tp;
2844
2845 memset(info, 0, sizeof(struct sysinfo));
2846
2847 ktime_get_boottime_ts64(&tp);
2848 timens_add_boottime(&tp);
2849 info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
2850
2851 get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);
2852
2853 info->procs = nr_threads;
2854
2855 si_meminfo(info);
2856 si_swapinfo(info);
2857
2858 /*
2859 * If the sum of all the available memory (i.e. ram + swap)
2860 * is less than can be stored in a 32 bit unsigned long then
2861 * we can be binary compatible with 2.2.x kernels. If not,
2862 * well, in that case 2.2.x was broken anyways...
2863 *
2864 * -Erik Andersen <andersee@debian.org>
2865 */
2866
2867 mem_total = info->totalram + info->totalswap;
2868 if (mem_total < info->totalram || mem_total < info->totalswap)
2869 goto out;
2870 bitcount = 0;
2871 mem_unit = info->mem_unit;
2872 while (mem_unit > 1) {
2873 bitcount++;
2874 mem_unit >>= 1;
2875 sav_total = mem_total;
2876 mem_total <<= 1;
2877 if (mem_total < sav_total)
2878 goto out;
2879 }
2880
2881 /*
2882 * If mem_total did not overflow, multiply all memory values by
2883 * info->mem_unit and set it to 1. This leaves things compatible
2884 * with 2.2.x, and also retains compatibility with earlier 2.4.x
2885 * kernels...
2886 */
2887
2888 info->mem_unit = 1;
2889 info->totalram <<= bitcount;
2890 info->freeram <<= bitcount;
2891 info->sharedram <<= bitcount;
2892 info->bufferram <<= bitcount;
2893 info->totalswap <<= bitcount;
2894 info->freeswap <<= bitcount;
2895 info->totalhigh <<= bitcount;
2896 info->freehigh <<= bitcount;
2897
2898 out:
2899 return 0;
2900 }
2901
SYSCALL_DEFINE1(sysinfo,struct sysinfo __user *,info)2902 SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info)
2903 {
2904 struct sysinfo val;
2905
2906 do_sysinfo(&val);
2907
2908 if (copy_to_user(info, &val, sizeof(struct sysinfo)))
2909 return -EFAULT;
2910
2911 return 0;
2912 }
2913
2914 #ifdef CONFIG_COMPAT
2915 struct compat_sysinfo {
2916 s32 uptime;
2917 u32 loads[3];
2918 u32 totalram;
2919 u32 freeram;
2920 u32 sharedram;
2921 u32 bufferram;
2922 u32 totalswap;
2923 u32 freeswap;
2924 u16 procs;
2925 u16 pad;
2926 u32 totalhigh;
2927 u32 freehigh;
2928 u32 mem_unit;
2929 char _f[20-2*sizeof(u32)-sizeof(int)];
2930 };
2931
COMPAT_SYSCALL_DEFINE1(sysinfo,struct compat_sysinfo __user *,info)2932 COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info)
2933 {
2934 struct sysinfo s;
2935 struct compat_sysinfo s_32;
2936
2937 do_sysinfo(&s);
2938
2939 /* Check to see if any memory value is too large for 32-bit and scale
2940 * down if needed
2941 */
2942 if (upper_32_bits(s.totalram) || upper_32_bits(s.totalswap)) {
2943 int bitcount = 0;
2944
2945 while (s.mem_unit < PAGE_SIZE) {
2946 s.mem_unit <<= 1;
2947 bitcount++;
2948 }
2949
2950 s.totalram >>= bitcount;
2951 s.freeram >>= bitcount;
2952 s.sharedram >>= bitcount;
2953 s.bufferram >>= bitcount;
2954 s.totalswap >>= bitcount;
2955 s.freeswap >>= bitcount;
2956 s.totalhigh >>= bitcount;
2957 s.freehigh >>= bitcount;
2958 }
2959
2960 memset(&s_32, 0, sizeof(s_32));
2961 s_32.uptime = s.uptime;
2962 s_32.loads[0] = s.loads[0];
2963 s_32.loads[1] = s.loads[1];
2964 s_32.loads[2] = s.loads[2];
2965 s_32.totalram = s.totalram;
2966 s_32.freeram = s.freeram;
2967 s_32.sharedram = s.sharedram;
2968 s_32.bufferram = s.bufferram;
2969 s_32.totalswap = s.totalswap;
2970 s_32.freeswap = s.freeswap;
2971 s_32.procs = s.procs;
2972 s_32.totalhigh = s.totalhigh;
2973 s_32.freehigh = s.freehigh;
2974 s_32.mem_unit = s.mem_unit;
2975 if (copy_to_user(info, &s_32, sizeof(s_32)))
2976 return -EFAULT;
2977 return 0;
2978 }
2979 #endif /* CONFIG_COMPAT */
2980