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