| 1 | /* |
| 2 | * linux/kernel/sys.c |
| 3 | * |
| 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
| 5 | */ |
| 6 | |
| 7 | #include <linux/export.h> |
| 8 | #include <linux/mm.h> |
| 9 | #include <linux/utsname.h> |
| 10 | #include <linux/mman.h> |
| 11 | #include <linux/reboot.h> |
| 12 | #include <linux/prctl.h> |
| 13 | #include <linux/highuid.h> |
| 14 | #include <linux/fs.h> |
| 15 | #include <linux/kmod.h> |
| 16 | #include <linux/perf_event.h> |
| 17 | #include <linux/resource.h> |
| 18 | #include <linux/kernel.h> |
| 19 | #include <linux/workqueue.h> |
| 20 | #include <linux/capability.h> |
| 21 | #include <linux/device.h> |
| 22 | #include <linux/key.h> |
| 23 | #include <linux/times.h> |
| 24 | #include <linux/posix-timers.h> |
| 25 | #include <linux/security.h> |
| 26 | #include <linux/dcookies.h> |
| 27 | #include <linux/suspend.h> |
| 28 | #include <linux/tty.h> |
| 29 | #include <linux/signal.h> |
| 30 | #include <linux/cn_proc.h> |
| 31 | #include <linux/getcpu.h> |
| 32 | #include <linux/task_io_accounting_ops.h> |
| 33 | #include <linux/seccomp.h> |
| 34 | #include <linux/cpu.h> |
| 35 | #include <linux/personality.h> |
| 36 | #include <linux/ptrace.h> |
| 37 | #include <linux/fs_struct.h> |
| 38 | #include <linux/file.h> |
| 39 | #include <linux/mount.h> |
| 40 | #include <linux/gfp.h> |
| 41 | #include <linux/syscore_ops.h> |
| 42 | #include <linux/version.h> |
| 43 | #include <linux/ctype.h> |
| 44 | |
| 45 | #include <linux/compat.h> |
| 46 | #include <linux/syscalls.h> |
| 47 | #include <linux/kprobes.h> |
| 48 | #include <linux/user_namespace.h> |
| 49 | #include <linux/binfmts.h> |
| 50 | |
| 51 | #include <linux/sched.h> |
| 52 | #include <linux/rcupdate.h> |
| 53 | #include <linux/uidgid.h> |
| 54 | #include <linux/cred.h> |
| 55 | |
| 56 | #include <linux/kmsg_dump.h> |
| 57 | /* Move somewhere else to avoid recompiling? */ |
| 58 | #include <generated/utsrelease.h> |
| 59 | |
| 60 | #include <asm/uaccess.h> |
| 61 | #include <asm/io.h> |
| 62 | #include <asm/unistd.h> |
| 63 | |
| 64 | #ifndef SET_UNALIGN_CTL |
| 65 | # define SET_UNALIGN_CTL(a,b) (-EINVAL) |
| 66 | #endif |
| 67 | #ifndef GET_UNALIGN_CTL |
| 68 | # define GET_UNALIGN_CTL(a,b) (-EINVAL) |
| 69 | #endif |
| 70 | #ifndef SET_FPEMU_CTL |
| 71 | # define SET_FPEMU_CTL(a,b) (-EINVAL) |
| 72 | #endif |
| 73 | #ifndef GET_FPEMU_CTL |
| 74 | # define GET_FPEMU_CTL(a,b) (-EINVAL) |
| 75 | #endif |
| 76 | #ifndef SET_FPEXC_CTL |
| 77 | # define SET_FPEXC_CTL(a,b) (-EINVAL) |
| 78 | #endif |
| 79 | #ifndef GET_FPEXC_CTL |
| 80 | # define GET_FPEXC_CTL(a,b) (-EINVAL) |
| 81 | #endif |
| 82 | #ifndef GET_ENDIAN |
| 83 | # define GET_ENDIAN(a,b) (-EINVAL) |
| 84 | #endif |
| 85 | #ifndef SET_ENDIAN |
| 86 | # define SET_ENDIAN(a,b) (-EINVAL) |
| 87 | #endif |
| 88 | #ifndef GET_TSC_CTL |
| 89 | # define GET_TSC_CTL(a) (-EINVAL) |
| 90 | #endif |
| 91 | #ifndef SET_TSC_CTL |
| 92 | # define SET_TSC_CTL(a) (-EINVAL) |
| 93 | #endif |
| 94 | |
| 95 | /* |
| 96 | * this is where the system-wide overflow UID and GID are defined, for |
| 97 | * architectures that now have 32-bit UID/GID but didn't in the past |
| 98 | */ |
| 99 | |
| 100 | int overflowuid = DEFAULT_OVERFLOWUID; |
| 101 | int overflowgid = DEFAULT_OVERFLOWGID; |
| 102 | |
| 103 | EXPORT_SYMBOL(overflowuid); |
| 104 | EXPORT_SYMBOL(overflowgid); |
| 105 | |
| 106 | /* |
| 107 | * the same as above, but for filesystems which can only store a 16-bit |
| 108 | * UID and GID. as such, this is needed on all architectures |
| 109 | */ |
| 110 | |
| 111 | int fs_overflowuid = DEFAULT_FS_OVERFLOWUID; |
| 112 | int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; |
| 113 | |
| 114 | EXPORT_SYMBOL(fs_overflowuid); |
| 115 | EXPORT_SYMBOL(fs_overflowgid); |
| 116 | |
| 117 | /* |
| 118 | * Returns true if current's euid is same as p's uid or euid, |
| 119 | * or has CAP_SYS_NICE to p's user_ns. |
| 120 | * |
| 121 | * Called with rcu_read_lock, creds are safe |
| 122 | */ |
| 123 | static bool set_one_prio_perm(struct task_struct *p) |
| 124 | { |
| 125 | const struct cred *cred = current_cred(), *pcred = __task_cred(p); |
| 126 | |
| 127 | if (uid_eq(pcred->uid, cred->euid) || |
| 128 | uid_eq(pcred->euid, cred->euid)) |
| 129 | return true; |
| 130 | if (ns_capable(pcred->user_ns, CAP_SYS_NICE)) |
| 131 | return true; |
| 132 | return false; |
| 133 | } |
| 134 | |
| 135 | /* |
| 136 | * set the priority of a task |
| 137 | * - the caller must hold the RCU read lock |
| 138 | */ |
| 139 | static int set_one_prio(struct task_struct *p, int niceval, int error) |
| 140 | { |
| 141 | int no_nice; |
| 142 | |
| 143 | if (!set_one_prio_perm(p)) { |
| 144 | error = -EPERM; |
| 145 | goto out; |
| 146 | } |
| 147 | if (niceval < task_nice(p) && !can_nice(p, niceval)) { |
| 148 | error = -EACCES; |
| 149 | goto out; |
| 150 | } |
| 151 | no_nice = security_task_setnice(p, niceval); |
| 152 | if (no_nice) { |
| 153 | error = no_nice; |
| 154 | goto out; |
| 155 | } |
| 156 | if (error == -ESRCH) |
| 157 | error = 0; |
| 158 | set_user_nice(p, niceval); |
| 159 | out: |
| 160 | return error; |
| 161 | } |
| 162 | |
| 163 | SYSCALL_DEFINE3(setpriority, int, which, int, who, int, niceval) |
| 164 | { |
| 165 | struct task_struct *g, *p; |
| 166 | struct user_struct *user; |
| 167 | const struct cred *cred = current_cred(); |
| 168 | int error = -EINVAL; |
| 169 | struct pid *pgrp; |
| 170 | kuid_t uid; |
| 171 | |
| 172 | if (which > PRIO_USER || which < PRIO_PROCESS) |
| 173 | goto out; |
| 174 | |
| 175 | /* normalize: avoid signed division (rounding problems) */ |
| 176 | error = -ESRCH; |
| 177 | if (niceval < -20) |
| 178 | niceval = -20; |
| 179 | if (niceval > 19) |
| 180 | niceval = 19; |
| 181 | |
| 182 | rcu_read_lock(); |
| 183 | read_lock(&tasklist_lock); |
| 184 | switch (which) { |
| 185 | case PRIO_PROCESS: |
| 186 | if (who) |
| 187 | p = find_task_by_vpid(who); |
| 188 | else |
| 189 | p = current; |
| 190 | if (p) |
| 191 | error = set_one_prio(p, niceval, error); |
| 192 | break; |
| 193 | case PRIO_PGRP: |
| 194 | if (who) |
| 195 | pgrp = find_vpid(who); |
| 196 | else |
| 197 | pgrp = task_pgrp(current); |
| 198 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { |
| 199 | error = set_one_prio(p, niceval, error); |
| 200 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); |
| 201 | break; |
| 202 | case PRIO_USER: |
| 203 | uid = make_kuid(cred->user_ns, who); |
| 204 | user = cred->user; |
| 205 | if (!who) |
| 206 | uid = cred->uid; |
| 207 | else if (!uid_eq(uid, cred->uid) && |
| 208 | !(user = find_user(uid))) |
| 209 | goto out_unlock; /* No processes for this user */ |
| 210 | |
| 211 | do_each_thread(g, p) { |
| 212 | if (uid_eq(task_uid(p), uid)) |
| 213 | error = set_one_prio(p, niceval, error); |
| 214 | } while_each_thread(g, p); |
| 215 | if (!uid_eq(uid, cred->uid)) |
| 216 | free_uid(user); /* For find_user() */ |
| 217 | break; |
| 218 | } |
| 219 | out_unlock: |
| 220 | read_unlock(&tasklist_lock); |
| 221 | rcu_read_unlock(); |
| 222 | out: |
| 223 | return error; |
| 224 | } |
| 225 | |
| 226 | /* |
| 227 | * Ugh. To avoid negative return values, "getpriority()" will |
| 228 | * not return the normal nice-value, but a negated value that |
| 229 | * has been offset by 20 (ie it returns 40..1 instead of -20..19) |
| 230 | * to stay compatible. |
| 231 | */ |
| 232 | SYSCALL_DEFINE2(getpriority, int, which, int, who) |
| 233 | { |
| 234 | struct task_struct *g, *p; |
| 235 | struct user_struct *user; |
| 236 | const struct cred *cred = current_cred(); |
| 237 | long niceval, retval = -ESRCH; |
| 238 | struct pid *pgrp; |
| 239 | kuid_t uid; |
| 240 | |
| 241 | if (which > PRIO_USER || which < PRIO_PROCESS) |
| 242 | return -EINVAL; |
| 243 | |
| 244 | rcu_read_lock(); |
| 245 | read_lock(&tasklist_lock); |
| 246 | switch (which) { |
| 247 | case PRIO_PROCESS: |
| 248 | if (who) |
| 249 | p = find_task_by_vpid(who); |
| 250 | else |
| 251 | p = current; |
| 252 | if (p) { |
| 253 | niceval = 20 - task_nice(p); |
| 254 | if (niceval > retval) |
| 255 | retval = niceval; |
| 256 | } |
| 257 | break; |
| 258 | case PRIO_PGRP: |
| 259 | if (who) |
| 260 | pgrp = find_vpid(who); |
| 261 | else |
| 262 | pgrp = task_pgrp(current); |
| 263 | do_each_pid_thread(pgrp, PIDTYPE_PGID, p) { |
| 264 | niceval = 20 - task_nice(p); |
| 265 | if (niceval > retval) |
| 266 | retval = niceval; |
| 267 | } while_each_pid_thread(pgrp, PIDTYPE_PGID, p); |
| 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 | goto out_unlock; /* No processes for this user */ |
| 277 | |
| 278 | do_each_thread(g, p) { |
| 279 | if (uid_eq(task_uid(p), uid)) { |
| 280 | niceval = 20 - task_nice(p); |
| 281 | if (niceval > retval) |
| 282 | retval = niceval; |
| 283 | } |
| 284 | } while_each_thread(g, p); |
| 285 | if (!uid_eq(uid, cred->uid)) |
| 286 | free_uid(user); /* for find_user() */ |
| 287 | break; |
| 288 | } |
| 289 | out_unlock: |
| 290 | read_unlock(&tasklist_lock); |
| 291 | rcu_read_unlock(); |
| 292 | |
| 293 | return retval; |
| 294 | } |
| 295 | |
| 296 | /* |
| 297 | * Unprivileged users may change the real gid to the effective gid |
| 298 | * or vice versa. (BSD-style) |
| 299 | * |
| 300 | * If you set the real gid at all, or set the effective gid to a value not |
| 301 | * equal to the real gid, then the saved gid is set to the new effective gid. |
| 302 | * |
| 303 | * This makes it possible for a setgid program to completely drop its |
| 304 | * privileges, which is often a useful assertion to make when you are doing |
| 305 | * a security audit over a program. |
| 306 | * |
| 307 | * The general idea is that a program which uses just setregid() will be |
| 308 | * 100% compatible with BSD. A program which uses just setgid() will be |
| 309 | * 100% compatible with POSIX with saved IDs. |
| 310 | * |
| 311 | * SMP: There are not races, the GIDs are checked only by filesystem |
| 312 | * operations (as far as semantic preservation is concerned). |
| 313 | */ |
| 314 | SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) |
| 315 | { |
| 316 | struct user_namespace *ns = current_user_ns(); |
| 317 | const struct cred *old; |
| 318 | struct cred *new; |
| 319 | int retval; |
| 320 | kgid_t krgid, kegid; |
| 321 | |
| 322 | krgid = make_kgid(ns, rgid); |
| 323 | kegid = make_kgid(ns, egid); |
| 324 | |
| 325 | if ((rgid != (gid_t) -1) && !gid_valid(krgid)) |
| 326 | return -EINVAL; |
| 327 | if ((egid != (gid_t) -1) && !gid_valid(kegid)) |
| 328 | return -EINVAL; |
| 329 | |
| 330 | new = prepare_creds(); |
| 331 | if (!new) |
| 332 | return -ENOMEM; |
| 333 | old = current_cred(); |
| 334 | |
| 335 | retval = -EPERM; |
| 336 | if (rgid != (gid_t) -1) { |
| 337 | if (gid_eq(old->gid, krgid) || |
| 338 | gid_eq(old->egid, krgid) || |
| 339 | ns_capable(old->user_ns, CAP_SETGID)) |
| 340 | new->gid = krgid; |
| 341 | else |
| 342 | goto error; |
| 343 | } |
| 344 | if (egid != (gid_t) -1) { |
| 345 | if (gid_eq(old->gid, kegid) || |
| 346 | gid_eq(old->egid, kegid) || |
| 347 | gid_eq(old->sgid, kegid) || |
| 348 | ns_capable(old->user_ns, CAP_SETGID)) |
| 349 | new->egid = kegid; |
| 350 | else |
| 351 | goto error; |
| 352 | } |
| 353 | |
| 354 | if (rgid != (gid_t) -1 || |
| 355 | (egid != (gid_t) -1 && !gid_eq(kegid, old->gid))) |
| 356 | new->sgid = new->egid; |
| 357 | new->fsgid = new->egid; |
| 358 | |
| 359 | return commit_creds(new); |
| 360 | |
| 361 | error: |
| 362 | abort_creds(new); |
| 363 | return retval; |
| 364 | } |
| 365 | |
| 366 | /* |
| 367 | * setgid() is implemented like SysV w/ SAVED_IDS |
| 368 | * |
| 369 | * SMP: Same implicit races as above. |
| 370 | */ |
| 371 | SYSCALL_DEFINE1(setgid, gid_t, gid) |
| 372 | { |
| 373 | struct user_namespace *ns = current_user_ns(); |
| 374 | const struct cred *old; |
| 375 | struct cred *new; |
| 376 | int retval; |
| 377 | kgid_t kgid; |
| 378 | |
| 379 | kgid = make_kgid(ns, gid); |
| 380 | if (!gid_valid(kgid)) |
| 381 | return -EINVAL; |
| 382 | |
| 383 | new = prepare_creds(); |
| 384 | if (!new) |
| 385 | return -ENOMEM; |
| 386 | old = current_cred(); |
| 387 | |
| 388 | retval = -EPERM; |
| 389 | if (ns_capable(old->user_ns, CAP_SETGID)) |
| 390 | new->gid = new->egid = new->sgid = new->fsgid = kgid; |
| 391 | else if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->sgid)) |
| 392 | new->egid = new->fsgid = kgid; |
| 393 | else |
| 394 | goto error; |
| 395 | |
| 396 | return commit_creds(new); |
| 397 | |
| 398 | error: |
| 399 | abort_creds(new); |
| 400 | return retval; |
| 401 | } |
| 402 | |
| 403 | /* |
| 404 | * change the user struct in a credentials set to match the new UID |
| 405 | */ |
| 406 | static int set_user(struct cred *new) |
| 407 | { |
| 408 | struct user_struct *new_user; |
| 409 | |
| 410 | new_user = alloc_uid(new->uid); |
| 411 | if (!new_user) |
| 412 | return -EAGAIN; |
| 413 | |
| 414 | /* |
| 415 | * We don't fail in case of NPROC limit excess here because too many |
| 416 | * poorly written programs don't check set*uid() return code, assuming |
| 417 | * it never fails if called by root. We may still enforce NPROC limit |
| 418 | * for programs doing set*uid()+execve() by harmlessly deferring the |
| 419 | * failure to the execve() stage. |
| 420 | */ |
| 421 | if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) && |
| 422 | new_user != INIT_USER) |
| 423 | current->flags |= PF_NPROC_EXCEEDED; |
| 424 | else |
| 425 | current->flags &= ~PF_NPROC_EXCEEDED; |
| 426 | |
| 427 | free_uid(new->user); |
| 428 | new->user = new_user; |
| 429 | return 0; |
| 430 | } |
| 431 | |
| 432 | /* |
| 433 | * Unprivileged users may change the real uid to the effective uid |
| 434 | * or vice versa. (BSD-style) |
| 435 | * |
| 436 | * If you set the real uid at all, or set the effective uid to a value not |
| 437 | * equal to the real uid, then the saved uid is set to the new effective uid. |
| 438 | * |
| 439 | * This makes it possible for a setuid program to completely drop its |
| 440 | * privileges, which is often a useful assertion to make when you are doing |
| 441 | * a security audit over a program. |
| 442 | * |
| 443 | * The general idea is that a program which uses just setreuid() will be |
| 444 | * 100% compatible with BSD. A program which uses just setuid() will be |
| 445 | * 100% compatible with POSIX with saved IDs. |
| 446 | */ |
| 447 | SYSCALL_DEFINE2(setreuid, uid_t, ruid, uid_t, euid) |
| 448 | { |
| 449 | struct user_namespace *ns = current_user_ns(); |
| 450 | const struct cred *old; |
| 451 | struct cred *new; |
| 452 | int retval; |
| 453 | kuid_t kruid, keuid; |
| 454 | |
| 455 | kruid = make_kuid(ns, ruid); |
| 456 | keuid = make_kuid(ns, euid); |
| 457 | |
| 458 | if ((ruid != (uid_t) -1) && !uid_valid(kruid)) |
| 459 | return -EINVAL; |
| 460 | if ((euid != (uid_t) -1) && !uid_valid(keuid)) |
| 461 | return -EINVAL; |
| 462 | |
| 463 | new = prepare_creds(); |
| 464 | if (!new) |
| 465 | return -ENOMEM; |
| 466 | old = current_cred(); |
| 467 | |
| 468 | retval = -EPERM; |
| 469 | if (ruid != (uid_t) -1) { |
| 470 | new->uid = kruid; |
| 471 | if (!uid_eq(old->uid, kruid) && |
| 472 | !uid_eq(old->euid, kruid) && |
| 473 | !ns_capable(old->user_ns, CAP_SETUID)) |
| 474 | goto error; |
| 475 | } |
| 476 | |
| 477 | if (euid != (uid_t) -1) { |
| 478 | new->euid = keuid; |
| 479 | if (!uid_eq(old->uid, keuid) && |
| 480 | !uid_eq(old->euid, keuid) && |
| 481 | !uid_eq(old->suid, keuid) && |
| 482 | !ns_capable(old->user_ns, CAP_SETUID)) |
| 483 | goto error; |
| 484 | } |
| 485 | |
| 486 | if (!uid_eq(new->uid, old->uid)) { |
| 487 | retval = set_user(new); |
| 488 | if (retval < 0) |
| 489 | goto error; |
| 490 | } |
| 491 | if (ruid != (uid_t) -1 || |
| 492 | (euid != (uid_t) -1 && !uid_eq(keuid, old->uid))) |
| 493 | new->suid = new->euid; |
| 494 | new->fsuid = new->euid; |
| 495 | |
| 496 | retval = security_task_fix_setuid(new, old, LSM_SETID_RE); |
| 497 | if (retval < 0) |
| 498 | goto error; |
| 499 | |
| 500 | return commit_creds(new); |
| 501 | |
| 502 | error: |
| 503 | abort_creds(new); |
| 504 | return retval; |
| 505 | } |
| 506 | |
| 507 | /* |
| 508 | * setuid() is implemented like SysV with SAVED_IDS |
| 509 | * |
| 510 | * Note that SAVED_ID's is deficient in that a setuid root program |
| 511 | * like sendmail, for example, cannot set its uid to be a normal |
| 512 | * user and then switch back, because if you're root, setuid() sets |
| 513 | * the saved uid too. If you don't like this, blame the bright people |
| 514 | * in the POSIX committee and/or USG. Note that the BSD-style setreuid() |
| 515 | * will allow a root program to temporarily drop privileges and be able to |
| 516 | * regain them by swapping the real and effective uid. |
| 517 | */ |
| 518 | SYSCALL_DEFINE1(setuid, uid_t, uid) |
| 519 | { |
| 520 | struct user_namespace *ns = current_user_ns(); |
| 521 | const struct cred *old; |
| 522 | struct cred *new; |
| 523 | int retval; |
| 524 | kuid_t kuid; |
| 525 | |
| 526 | kuid = make_kuid(ns, uid); |
| 527 | if (!uid_valid(kuid)) |
| 528 | return -EINVAL; |
| 529 | |
| 530 | new = prepare_creds(); |
| 531 | if (!new) |
| 532 | return -ENOMEM; |
| 533 | old = current_cred(); |
| 534 | |
| 535 | retval = -EPERM; |
| 536 | if (ns_capable(old->user_ns, CAP_SETUID)) { |
| 537 | new->suid = new->uid = kuid; |
| 538 | if (!uid_eq(kuid, old->uid)) { |
| 539 | retval = set_user(new); |
| 540 | if (retval < 0) |
| 541 | goto error; |
| 542 | } |
| 543 | } else if (!uid_eq(kuid, old->uid) && !uid_eq(kuid, new->suid)) { |
| 544 | goto error; |
| 545 | } |
| 546 | |
| 547 | new->fsuid = new->euid = kuid; |
| 548 | |
| 549 | retval = security_task_fix_setuid(new, old, LSM_SETID_ID); |
| 550 | if (retval < 0) |
| 551 | goto error; |
| 552 | |
| 553 | return commit_creds(new); |
| 554 | |
| 555 | error: |
| 556 | abort_creds(new); |
| 557 | return retval; |
| 558 | } |
| 559 | |
| 560 | |
| 561 | /* |
| 562 | * This function implements a generic ability to update ruid, euid, |
| 563 | * and suid. This allows you to implement the 4.4 compatible seteuid(). |
| 564 | */ |
| 565 | SYSCALL_DEFINE3(setresuid, uid_t, ruid, uid_t, euid, uid_t, suid) |
| 566 | { |
| 567 | struct user_namespace *ns = current_user_ns(); |
| 568 | const struct cred *old; |
| 569 | struct cred *new; |
| 570 | int retval; |
| 571 | kuid_t kruid, keuid, ksuid; |
| 572 | |
| 573 | kruid = make_kuid(ns, ruid); |
| 574 | keuid = make_kuid(ns, euid); |
| 575 | ksuid = make_kuid(ns, suid); |
| 576 | |
| 577 | if ((ruid != (uid_t) -1) && !uid_valid(kruid)) |
| 578 | return -EINVAL; |
| 579 | |
| 580 | if ((euid != (uid_t) -1) && !uid_valid(keuid)) |
| 581 | return -EINVAL; |
| 582 | |
| 583 | if ((suid != (uid_t) -1) && !uid_valid(ksuid)) |
| 584 | return -EINVAL; |
| 585 | |
| 586 | new = prepare_creds(); |
| 587 | if (!new) |
| 588 | return -ENOMEM; |
| 589 | |
| 590 | old = current_cred(); |
| 591 | |
| 592 | retval = -EPERM; |
| 593 | if (!ns_capable(old->user_ns, CAP_SETUID)) { |
| 594 | if (ruid != (uid_t) -1 && !uid_eq(kruid, old->uid) && |
| 595 | !uid_eq(kruid, old->euid) && !uid_eq(kruid, old->suid)) |
| 596 | goto error; |
| 597 | if (euid != (uid_t) -1 && !uid_eq(keuid, old->uid) && |
| 598 | !uid_eq(keuid, old->euid) && !uid_eq(keuid, old->suid)) |
| 599 | goto error; |
| 600 | if (suid != (uid_t) -1 && !uid_eq(ksuid, old->uid) && |
| 601 | !uid_eq(ksuid, old->euid) && !uid_eq(ksuid, old->suid)) |
| 602 | goto error; |
| 603 | } |
| 604 | |
| 605 | if (ruid != (uid_t) -1) { |
| 606 | new->uid = kruid; |
| 607 | if (!uid_eq(kruid, old->uid)) { |
| 608 | retval = set_user(new); |
| 609 | if (retval < 0) |
| 610 | goto error; |
| 611 | } |
| 612 | } |
| 613 | if (euid != (uid_t) -1) |
| 614 | new->euid = keuid; |
| 615 | if (suid != (uid_t) -1) |
| 616 | new->suid = ksuid; |
| 617 | new->fsuid = new->euid; |
| 618 | |
| 619 | retval = security_task_fix_setuid(new, old, LSM_SETID_RES); |
| 620 | if (retval < 0) |
| 621 | goto error; |
| 622 | |
| 623 | return commit_creds(new); |
| 624 | |
| 625 | error: |
| 626 | abort_creds(new); |
| 627 | return retval; |
| 628 | } |
| 629 | |
| 630 | SYSCALL_DEFINE3(getresuid, uid_t __user *, ruidp, uid_t __user *, euidp, uid_t __user *, suidp) |
| 631 | { |
| 632 | const struct cred *cred = current_cred(); |
| 633 | int retval; |
| 634 | uid_t ruid, euid, suid; |
| 635 | |
| 636 | ruid = from_kuid_munged(cred->user_ns, cred->uid); |
| 637 | euid = from_kuid_munged(cred->user_ns, cred->euid); |
| 638 | suid = from_kuid_munged(cred->user_ns, cred->suid); |
| 639 | |
| 640 | if (!(retval = put_user(ruid, ruidp)) && |
| 641 | !(retval = put_user(euid, euidp))) |
| 642 | retval = put_user(suid, suidp); |
| 643 | |
| 644 | return retval; |
| 645 | } |
| 646 | |
| 647 | /* |
| 648 | * Same as above, but for rgid, egid, sgid. |
| 649 | */ |
| 650 | SYSCALL_DEFINE3(setresgid, gid_t, rgid, gid_t, egid, gid_t, sgid) |
| 651 | { |
| 652 | struct user_namespace *ns = current_user_ns(); |
| 653 | const struct cred *old; |
| 654 | struct cred *new; |
| 655 | int retval; |
| 656 | kgid_t krgid, kegid, ksgid; |
| 657 | |
| 658 | krgid = make_kgid(ns, rgid); |
| 659 | kegid = make_kgid(ns, egid); |
| 660 | ksgid = make_kgid(ns, sgid); |
| 661 | |
| 662 | if ((rgid != (gid_t) -1) && !gid_valid(krgid)) |
| 663 | return -EINVAL; |
| 664 | if ((egid != (gid_t) -1) && !gid_valid(kegid)) |
| 665 | return -EINVAL; |
| 666 | if ((sgid != (gid_t) -1) && !gid_valid(ksgid)) |
| 667 | return -EINVAL; |
| 668 | |
| 669 | new = prepare_creds(); |
| 670 | if (!new) |
| 671 | return -ENOMEM; |
| 672 | old = current_cred(); |
| 673 | |
| 674 | retval = -EPERM; |
| 675 | if (!ns_capable(old->user_ns, CAP_SETGID)) { |
| 676 | if (rgid != (gid_t) -1 && !gid_eq(krgid, old->gid) && |
| 677 | !gid_eq(krgid, old->egid) && !gid_eq(krgid, old->sgid)) |
| 678 | goto error; |
| 679 | if (egid != (gid_t) -1 && !gid_eq(kegid, old->gid) && |
| 680 | !gid_eq(kegid, old->egid) && !gid_eq(kegid, old->sgid)) |
| 681 | goto error; |
| 682 | if (sgid != (gid_t) -1 && !gid_eq(ksgid, old->gid) && |
| 683 | !gid_eq(ksgid, old->egid) && !gid_eq(ksgid, old->sgid)) |
| 684 | goto error; |
| 685 | } |
| 686 | |
| 687 | if (rgid != (gid_t) -1) |
| 688 | new->gid = krgid; |
| 689 | if (egid != (gid_t) -1) |
| 690 | new->egid = kegid; |
| 691 | if (sgid != (gid_t) -1) |
| 692 | new->sgid = ksgid; |
| 693 | new->fsgid = new->egid; |
| 694 | |
| 695 | return commit_creds(new); |
| 696 | |
| 697 | error: |
| 698 | abort_creds(new); |
| 699 | return retval; |
| 700 | } |
| 701 | |
| 702 | SYSCALL_DEFINE3(getresgid, gid_t __user *, rgidp, gid_t __user *, egidp, gid_t __user *, sgidp) |
| 703 | { |
| 704 | const struct cred *cred = current_cred(); |
| 705 | int retval; |
| 706 | gid_t rgid, egid, sgid; |
| 707 | |
| 708 | rgid = from_kgid_munged(cred->user_ns, cred->gid); |
| 709 | egid = from_kgid_munged(cred->user_ns, cred->egid); |
| 710 | sgid = from_kgid_munged(cred->user_ns, cred->sgid); |
| 711 | |
| 712 | if (!(retval = put_user(rgid, rgidp)) && |
| 713 | !(retval = put_user(egid, egidp))) |
| 714 | retval = put_user(sgid, sgidp); |
| 715 | |
| 716 | return retval; |
| 717 | } |
| 718 | |
| 719 | |
| 720 | /* |
| 721 | * "setfsuid()" sets the fsuid - the uid used for filesystem checks. This |
| 722 | * is used for "access()" and for the NFS daemon (letting nfsd stay at |
| 723 | * whatever uid it wants to). It normally shadows "euid", except when |
| 724 | * explicitly set by setfsuid() or for access.. |
| 725 | */ |
| 726 | SYSCALL_DEFINE1(setfsuid, uid_t, uid) |
| 727 | { |
| 728 | const struct cred *old; |
| 729 | struct cred *new; |
| 730 | uid_t old_fsuid; |
| 731 | kuid_t kuid; |
| 732 | |
| 733 | old = current_cred(); |
| 734 | old_fsuid = from_kuid_munged(old->user_ns, old->fsuid); |
| 735 | |
| 736 | kuid = make_kuid(old->user_ns, uid); |
| 737 | if (!uid_valid(kuid)) |
| 738 | return old_fsuid; |
| 739 | |
| 740 | new = prepare_creds(); |
| 741 | if (!new) |
| 742 | return old_fsuid; |
| 743 | |
| 744 | if (uid_eq(kuid, old->uid) || uid_eq(kuid, old->euid) || |
| 745 | uid_eq(kuid, old->suid) || uid_eq(kuid, old->fsuid) || |
| 746 | ns_capable(old->user_ns, CAP_SETUID)) { |
| 747 | if (!uid_eq(kuid, old->fsuid)) { |
| 748 | new->fsuid = kuid; |
| 749 | if (security_task_fix_setuid(new, old, LSM_SETID_FS) == 0) |
| 750 | goto change_okay; |
| 751 | } |
| 752 | } |
| 753 | |
| 754 | abort_creds(new); |
| 755 | return old_fsuid; |
| 756 | |
| 757 | change_okay: |
| 758 | commit_creds(new); |
| 759 | return old_fsuid; |
| 760 | } |
| 761 | |
| 762 | /* |
| 763 | * Samma på svenska.. |
| 764 | */ |
| 765 | SYSCALL_DEFINE1(setfsgid, gid_t, gid) |
| 766 | { |
| 767 | const struct cred *old; |
| 768 | struct cred *new; |
| 769 | gid_t old_fsgid; |
| 770 | kgid_t kgid; |
| 771 | |
| 772 | old = current_cred(); |
| 773 | old_fsgid = from_kgid_munged(old->user_ns, old->fsgid); |
| 774 | |
| 775 | kgid = make_kgid(old->user_ns, gid); |
| 776 | if (!gid_valid(kgid)) |
| 777 | return old_fsgid; |
| 778 | |
| 779 | new = prepare_creds(); |
| 780 | if (!new) |
| 781 | return old_fsgid; |
| 782 | |
| 783 | if (gid_eq(kgid, old->gid) || gid_eq(kgid, old->egid) || |
| 784 | gid_eq(kgid, old->sgid) || gid_eq(kgid, old->fsgid) || |
| 785 | ns_capable(old->user_ns, CAP_SETGID)) { |
| 786 | if (!gid_eq(kgid, old->fsgid)) { |
| 787 | new->fsgid = kgid; |
| 788 | goto change_okay; |
| 789 | } |
| 790 | } |
| 791 | |
| 792 | abort_creds(new); |
| 793 | return old_fsgid; |
| 794 | |
| 795 | change_okay: |
| 796 | commit_creds(new); |
| 797 | return old_fsgid; |
| 798 | } |
| 799 | |
| 800 | /** |
| 801 | * sys_getpid - return the thread group id of the current process |
| 802 | * |
| 803 | * Note, despite the name, this returns the tgid not the pid. The tgid and |
| 804 | * the pid are identical unless CLONE_THREAD was specified on clone() in |
| 805 | * which case the tgid is the same in all threads of the same group. |
| 806 | * |
| 807 | * This is SMP safe as current->tgid does not change. |
| 808 | */ |
| 809 | SYSCALL_DEFINE0(getpid) |
| 810 | { |
| 811 | return task_tgid_vnr(current); |
| 812 | } |
| 813 | |
| 814 | /* Thread ID - the internal kernel "pid" */ |
| 815 | SYSCALL_DEFINE0(gettid) |
| 816 | { |
| 817 | return task_pid_vnr(current); |
| 818 | } |
| 819 | |
| 820 | /* |
| 821 | * Accessing ->real_parent is not SMP-safe, it could |
| 822 | * change from under us. However, we can use a stale |
| 823 | * value of ->real_parent under rcu_read_lock(), see |
| 824 | * release_task()->call_rcu(delayed_put_task_struct). |
| 825 | */ |
| 826 | SYSCALL_DEFINE0(getppid) |
| 827 | { |
| 828 | int pid; |
| 829 | |
| 830 | rcu_read_lock(); |
| 831 | pid = task_tgid_vnr(rcu_dereference(current->real_parent)); |
| 832 | rcu_read_unlock(); |
| 833 | |
| 834 | return pid; |
| 835 | } |
| 836 | |
| 837 | SYSCALL_DEFINE0(getuid) |
| 838 | { |
| 839 | /* Only we change this so SMP safe */ |
| 840 | return from_kuid_munged(current_user_ns(), current_uid()); |
| 841 | } |
| 842 | |
| 843 | SYSCALL_DEFINE0(geteuid) |
| 844 | { |
| 845 | /* Only we change this so SMP safe */ |
| 846 | return from_kuid_munged(current_user_ns(), current_euid()); |
| 847 | } |
| 848 | |
| 849 | SYSCALL_DEFINE0(getgid) |
| 850 | { |
| 851 | /* Only we change this so SMP safe */ |
| 852 | return from_kgid_munged(current_user_ns(), current_gid()); |
| 853 | } |
| 854 | |
| 855 | SYSCALL_DEFINE0(getegid) |
| 856 | { |
| 857 | /* Only we change this so SMP safe */ |
| 858 | return from_kgid_munged(current_user_ns(), current_egid()); |
| 859 | } |
| 860 | |
| 861 | void do_sys_times(struct tms *tms) |
| 862 | { |
| 863 | cputime_t tgutime, tgstime, cutime, cstime; |
| 864 | |
| 865 | spin_lock_irq(¤t->sighand->siglock); |
| 866 | thread_group_cputime_adjusted(current, &tgutime, &tgstime); |
| 867 | cutime = current->signal->cutime; |
| 868 | cstime = current->signal->cstime; |
| 869 | spin_unlock_irq(¤t->sighand->siglock); |
| 870 | tms->tms_utime = cputime_to_clock_t(tgutime); |
| 871 | tms->tms_stime = cputime_to_clock_t(tgstime); |
| 872 | tms->tms_cutime = cputime_to_clock_t(cutime); |
| 873 | tms->tms_cstime = cputime_to_clock_t(cstime); |
| 874 | } |
| 875 | |
| 876 | SYSCALL_DEFINE1(times, struct tms __user *, tbuf) |
| 877 | { |
| 878 | if (tbuf) { |
| 879 | struct tms tmp; |
| 880 | |
| 881 | do_sys_times(&tmp); |
| 882 | if (copy_to_user(tbuf, &tmp, sizeof(struct tms))) |
| 883 | return -EFAULT; |
| 884 | } |
| 885 | force_successful_syscall_return(); |
| 886 | return (long) jiffies_64_to_clock_t(get_jiffies_64()); |
| 887 | } |
| 888 | |
| 889 | /* |
| 890 | * This needs some heavy checking ... |
| 891 | * I just haven't the stomach for it. I also don't fully |
| 892 | * understand sessions/pgrp etc. Let somebody who does explain it. |
| 893 | * |
| 894 | * OK, I think I have the protection semantics right.... this is really |
| 895 | * only important on a multi-user system anyway, to make sure one user |
| 896 | * can't send a signal to a process owned by another. -TYT, 12/12/91 |
| 897 | * |
| 898 | * !PF_FORKNOEXEC check to conform completely to POSIX. |
| 899 | */ |
| 900 | SYSCALL_DEFINE2(setpgid, pid_t, pid, pid_t, pgid) |
| 901 | { |
| 902 | struct task_struct *p; |
| 903 | struct task_struct *group_leader = current->group_leader; |
| 904 | struct pid *pgrp; |
| 905 | int err; |
| 906 | |
| 907 | if (!pid) |
| 908 | pid = task_pid_vnr(group_leader); |
| 909 | if (!pgid) |
| 910 | pgid = pid; |
| 911 | if (pgid < 0) |
| 912 | return -EINVAL; |
| 913 | rcu_read_lock(); |
| 914 | |
| 915 | /* From this point forward we keep holding onto the tasklist lock |
| 916 | * so that our parent does not change from under us. -DaveM |
| 917 | */ |
| 918 | write_lock_irq(&tasklist_lock); |
| 919 | |
| 920 | err = -ESRCH; |
| 921 | p = find_task_by_vpid(pid); |
| 922 | if (!p) |
| 923 | goto out; |
| 924 | |
| 925 | err = -EINVAL; |
| 926 | if (!thread_group_leader(p)) |
| 927 | goto out; |
| 928 | |
| 929 | if (same_thread_group(p->real_parent, group_leader)) { |
| 930 | err = -EPERM; |
| 931 | if (task_session(p) != task_session(group_leader)) |
| 932 | goto out; |
| 933 | err = -EACCES; |
| 934 | if (!(p->flags & PF_FORKNOEXEC)) |
| 935 | goto out; |
| 936 | } else { |
| 937 | err = -ESRCH; |
| 938 | if (p != group_leader) |
| 939 | goto out; |
| 940 | } |
| 941 | |
| 942 | err = -EPERM; |
| 943 | if (p->signal->leader) |
| 944 | goto out; |
| 945 | |
| 946 | pgrp = task_pid(p); |
| 947 | if (pgid != pid) { |
| 948 | struct task_struct *g; |
| 949 | |
| 950 | pgrp = find_vpid(pgid); |
| 951 | g = pid_task(pgrp, PIDTYPE_PGID); |
| 952 | if (!g || task_session(g) != task_session(group_leader)) |
| 953 | goto out; |
| 954 | } |
| 955 | |
| 956 | err = security_task_setpgid(p, pgid); |
| 957 | if (err) |
| 958 | goto out; |
| 959 | |
| 960 | if (task_pgrp(p) != pgrp) |
| 961 | change_pid(p, PIDTYPE_PGID, pgrp); |
| 962 | |
| 963 | err = 0; |
| 964 | out: |
| 965 | /* All paths lead to here, thus we are safe. -DaveM */ |
| 966 | write_unlock_irq(&tasklist_lock); |
| 967 | rcu_read_unlock(); |
| 968 | return err; |
| 969 | } |
| 970 | |
| 971 | SYSCALL_DEFINE1(getpgid, pid_t, pid) |
| 972 | { |
| 973 | struct task_struct *p; |
| 974 | struct pid *grp; |
| 975 | int retval; |
| 976 | |
| 977 | rcu_read_lock(); |
| 978 | if (!pid) |
| 979 | grp = task_pgrp(current); |
| 980 | else { |
| 981 | retval = -ESRCH; |
| 982 | p = find_task_by_vpid(pid); |
| 983 | if (!p) |
| 984 | goto out; |
| 985 | grp = task_pgrp(p); |
| 986 | if (!grp) |
| 987 | goto out; |
| 988 | |
| 989 | retval = security_task_getpgid(p); |
| 990 | if (retval) |
| 991 | goto out; |
| 992 | } |
| 993 | retval = pid_vnr(grp); |
| 994 | out: |
| 995 | rcu_read_unlock(); |
| 996 | return retval; |
| 997 | } |
| 998 | |
| 999 | #ifdef __ARCH_WANT_SYS_GETPGRP |
| 1000 | |
| 1001 | SYSCALL_DEFINE0(getpgrp) |
| 1002 | { |
| 1003 | return sys_getpgid(0); |
| 1004 | } |
| 1005 | |
| 1006 | #endif |
| 1007 | |
| 1008 | SYSCALL_DEFINE1(getsid, pid_t, pid) |
| 1009 | { |
| 1010 | struct task_struct *p; |
| 1011 | struct pid *sid; |
| 1012 | int retval; |
| 1013 | |
| 1014 | rcu_read_lock(); |
| 1015 | if (!pid) |
| 1016 | sid = task_session(current); |
| 1017 | else { |
| 1018 | retval = -ESRCH; |
| 1019 | p = find_task_by_vpid(pid); |
| 1020 | if (!p) |
| 1021 | goto out; |
| 1022 | sid = task_session(p); |
| 1023 | if (!sid) |
| 1024 | goto out; |
| 1025 | |
| 1026 | retval = security_task_getsid(p); |
| 1027 | if (retval) |
| 1028 | goto out; |
| 1029 | } |
| 1030 | retval = pid_vnr(sid); |
| 1031 | out: |
| 1032 | rcu_read_unlock(); |
| 1033 | return retval; |
| 1034 | } |
| 1035 | |
| 1036 | static void set_special_pids(struct pid *pid) |
| 1037 | { |
| 1038 | struct task_struct *curr = current->group_leader; |
| 1039 | |
| 1040 | if (task_session(curr) != pid) |
| 1041 | change_pid(curr, PIDTYPE_SID, pid); |
| 1042 | |
| 1043 | if (task_pgrp(curr) != pid) |
| 1044 | change_pid(curr, PIDTYPE_PGID, pid); |
| 1045 | } |
| 1046 | |
| 1047 | SYSCALL_DEFINE0(setsid) |
| 1048 | { |
| 1049 | struct task_struct *group_leader = current->group_leader; |
| 1050 | struct pid *sid = task_pid(group_leader); |
| 1051 | pid_t session = pid_vnr(sid); |
| 1052 | int err = -EPERM; |
| 1053 | |
| 1054 | write_lock_irq(&tasklist_lock); |
| 1055 | /* Fail if I am already a session leader */ |
| 1056 | if (group_leader->signal->leader) |
| 1057 | goto out; |
| 1058 | |
| 1059 | /* Fail if a process group id already exists that equals the |
| 1060 | * proposed session id. |
| 1061 | */ |
| 1062 | if (pid_task(sid, PIDTYPE_PGID)) |
| 1063 | goto out; |
| 1064 | |
| 1065 | group_leader->signal->leader = 1; |
| 1066 | set_special_pids(sid); |
| 1067 | |
| 1068 | proc_clear_tty(group_leader); |
| 1069 | |
| 1070 | err = session; |
| 1071 | out: |
| 1072 | write_unlock_irq(&tasklist_lock); |
| 1073 | if (err > 0) { |
| 1074 | proc_sid_connector(group_leader); |
| 1075 | sched_autogroup_create_attach(group_leader); |
| 1076 | } |
| 1077 | return err; |
| 1078 | } |
| 1079 | |
| 1080 | DECLARE_RWSEM(uts_sem); |
| 1081 | |
| 1082 | #ifdef COMPAT_UTS_MACHINE |
| 1083 | #define override_architecture(name) \ |
| 1084 | (personality(current->personality) == PER_LINUX32 && \ |
| 1085 | copy_to_user(name->machine, COMPAT_UTS_MACHINE, \ |
| 1086 | sizeof(COMPAT_UTS_MACHINE))) |
| 1087 | #else |
| 1088 | #define override_architecture(name) 0 |
| 1089 | #endif |
| 1090 | |
| 1091 | /* |
| 1092 | * Work around broken programs that cannot handle "Linux 3.0". |
| 1093 | * Instead we map 3.x to 2.6.40+x, so e.g. 3.0 would be 2.6.40 |
| 1094 | */ |
| 1095 | static int override_release(char __user *release, size_t len) |
| 1096 | { |
| 1097 | int ret = 0; |
| 1098 | |
| 1099 | if (current->personality & UNAME26) { |
| 1100 | const char *rest = UTS_RELEASE; |
| 1101 | char buf[65] = { 0 }; |
| 1102 | int ndots = 0; |
| 1103 | unsigned v; |
| 1104 | size_t copy; |
| 1105 | |
| 1106 | while (*rest) { |
| 1107 | if (*rest == '.' && ++ndots >= 3) |
| 1108 | break; |
| 1109 | if (!isdigit(*rest) && *rest != '.') |
| 1110 | break; |
| 1111 | rest++; |
| 1112 | } |
| 1113 | v = ((LINUX_VERSION_CODE >> 8) & 0xff) + 40; |
| 1114 | copy = clamp_t(size_t, len, 1, sizeof(buf)); |
| 1115 | copy = scnprintf(buf, copy, "2.6.%u%s", v, rest); |
| 1116 | ret = copy_to_user(release, buf, copy + 1); |
| 1117 | } |
| 1118 | return ret; |
| 1119 | } |
| 1120 | |
| 1121 | SYSCALL_DEFINE1(newuname, struct new_utsname __user *, name) |
| 1122 | { |
| 1123 | int errno = 0; |
| 1124 | |
| 1125 | down_read(&uts_sem); |
| 1126 | if (copy_to_user(name, utsname(), sizeof *name)) |
| 1127 | errno = -EFAULT; |
| 1128 | up_read(&uts_sem); |
| 1129 | |
| 1130 | if (!errno && override_release(name->release, sizeof(name->release))) |
| 1131 | errno = -EFAULT; |
| 1132 | if (!errno && override_architecture(name)) |
| 1133 | errno = -EFAULT; |
| 1134 | return errno; |
| 1135 | } |
| 1136 | |
| 1137 | #ifdef __ARCH_WANT_SYS_OLD_UNAME |
| 1138 | /* |
| 1139 | * Old cruft |
| 1140 | */ |
| 1141 | SYSCALL_DEFINE1(uname, struct old_utsname __user *, name) |
| 1142 | { |
| 1143 | int error = 0; |
| 1144 | |
| 1145 | if (!name) |
| 1146 | return -EFAULT; |
| 1147 | |
| 1148 | down_read(&uts_sem); |
| 1149 | if (copy_to_user(name, utsname(), sizeof(*name))) |
| 1150 | error = -EFAULT; |
| 1151 | up_read(&uts_sem); |
| 1152 | |
| 1153 | if (!error && override_release(name->release, sizeof(name->release))) |
| 1154 | error = -EFAULT; |
| 1155 | if (!error && override_architecture(name)) |
| 1156 | error = -EFAULT; |
| 1157 | return error; |
| 1158 | } |
| 1159 | |
| 1160 | SYSCALL_DEFINE1(olduname, struct oldold_utsname __user *, name) |
| 1161 | { |
| 1162 | int error; |
| 1163 | |
| 1164 | if (!name) |
| 1165 | return -EFAULT; |
| 1166 | if (!access_ok(VERIFY_WRITE, name, sizeof(struct oldold_utsname))) |
| 1167 | return -EFAULT; |
| 1168 | |
| 1169 | down_read(&uts_sem); |
| 1170 | error = __copy_to_user(&name->sysname, &utsname()->sysname, |
| 1171 | __OLD_UTS_LEN); |
| 1172 | error |= __put_user(0, name->sysname + __OLD_UTS_LEN); |
| 1173 | error |= __copy_to_user(&name->nodename, &utsname()->nodename, |
| 1174 | __OLD_UTS_LEN); |
| 1175 | error |= __put_user(0, name->nodename + __OLD_UTS_LEN); |
| 1176 | error |= __copy_to_user(&name->release, &utsname()->release, |
| 1177 | __OLD_UTS_LEN); |
| 1178 | error |= __put_user(0, name->release + __OLD_UTS_LEN); |
| 1179 | error |= __copy_to_user(&name->version, &utsname()->version, |
| 1180 | __OLD_UTS_LEN); |
| 1181 | error |= __put_user(0, name->version + __OLD_UTS_LEN); |
| 1182 | error |= __copy_to_user(&name->machine, &utsname()->machine, |
| 1183 | __OLD_UTS_LEN); |
| 1184 | error |= __put_user(0, name->machine + __OLD_UTS_LEN); |
| 1185 | up_read(&uts_sem); |
| 1186 | |
| 1187 | if (!error && override_architecture(name)) |
| 1188 | error = -EFAULT; |
| 1189 | if (!error && override_release(name->release, sizeof(name->release))) |
| 1190 | error = -EFAULT; |
| 1191 | return error ? -EFAULT : 0; |
| 1192 | } |
| 1193 | #endif |
| 1194 | |
| 1195 | SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) |
| 1196 | { |
| 1197 | int errno; |
| 1198 | char tmp[__NEW_UTS_LEN]; |
| 1199 | |
| 1200 | if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) |
| 1201 | return -EPERM; |
| 1202 | |
| 1203 | if (len < 0 || len > __NEW_UTS_LEN) |
| 1204 | return -EINVAL; |
| 1205 | down_write(&uts_sem); |
| 1206 | errno = -EFAULT; |
| 1207 | if (!copy_from_user(tmp, name, len)) { |
| 1208 | struct new_utsname *u = utsname(); |
| 1209 | |
| 1210 | memcpy(u->nodename, tmp, len); |
| 1211 | memset(u->nodename + len, 0, sizeof(u->nodename) - len); |
| 1212 | errno = 0; |
| 1213 | uts_proc_notify(UTS_PROC_HOSTNAME); |
| 1214 | } |
| 1215 | up_write(&uts_sem); |
| 1216 | return errno; |
| 1217 | } |
| 1218 | |
| 1219 | #ifdef __ARCH_WANT_SYS_GETHOSTNAME |
| 1220 | |
| 1221 | SYSCALL_DEFINE2(gethostname, char __user *, name, int, len) |
| 1222 | { |
| 1223 | int i, errno; |
| 1224 | struct new_utsname *u; |
| 1225 | |
| 1226 | if (len < 0) |
| 1227 | return -EINVAL; |
| 1228 | down_read(&uts_sem); |
| 1229 | u = utsname(); |
| 1230 | i = 1 + strlen(u->nodename); |
| 1231 | if (i > len) |
| 1232 | i = len; |
| 1233 | errno = 0; |
| 1234 | if (copy_to_user(name, u->nodename, i)) |
| 1235 | errno = -EFAULT; |
| 1236 | up_read(&uts_sem); |
| 1237 | return errno; |
| 1238 | } |
| 1239 | |
| 1240 | #endif |
| 1241 | |
| 1242 | /* |
| 1243 | * Only setdomainname; getdomainname can be implemented by calling |
| 1244 | * uname() |
| 1245 | */ |
| 1246 | SYSCALL_DEFINE2(setdomainname, char __user *, name, int, len) |
| 1247 | { |
| 1248 | int errno; |
| 1249 | char tmp[__NEW_UTS_LEN]; |
| 1250 | |
| 1251 | if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) |
| 1252 | return -EPERM; |
| 1253 | if (len < 0 || len > __NEW_UTS_LEN) |
| 1254 | return -EINVAL; |
| 1255 | |
| 1256 | down_write(&uts_sem); |
| 1257 | errno = -EFAULT; |
| 1258 | if (!copy_from_user(tmp, name, len)) { |
| 1259 | struct new_utsname *u = utsname(); |
| 1260 | |
| 1261 | memcpy(u->domainname, tmp, len); |
| 1262 | memset(u->domainname + len, 0, sizeof(u->domainname) - len); |
| 1263 | errno = 0; |
| 1264 | uts_proc_notify(UTS_PROC_DOMAINNAME); |
| 1265 | } |
| 1266 | up_write(&uts_sem); |
| 1267 | return errno; |
| 1268 | } |
| 1269 | |
| 1270 | SYSCALL_DEFINE2(getrlimit, unsigned int, resource, struct rlimit __user *, rlim) |
| 1271 | { |
| 1272 | struct rlimit value; |
| 1273 | int ret; |
| 1274 | |
| 1275 | ret = do_prlimit(current, resource, NULL, &value); |
| 1276 | if (!ret) |
| 1277 | ret = copy_to_user(rlim, &value, sizeof(*rlim)) ? -EFAULT : 0; |
| 1278 | |
| 1279 | return ret; |
| 1280 | } |
| 1281 | |
| 1282 | #ifdef __ARCH_WANT_SYS_OLD_GETRLIMIT |
| 1283 | |
| 1284 | /* |
| 1285 | * Back compatibility for getrlimit. Needed for some apps. |
| 1286 | */ |
| 1287 | |
| 1288 | SYSCALL_DEFINE2(old_getrlimit, unsigned int, resource, |
| 1289 | struct rlimit __user *, rlim) |
| 1290 | { |
| 1291 | struct rlimit x; |
| 1292 | if (resource >= RLIM_NLIMITS) |
| 1293 | return -EINVAL; |
| 1294 | |
| 1295 | task_lock(current->group_leader); |
| 1296 | x = current->signal->rlim[resource]; |
| 1297 | task_unlock(current->group_leader); |
| 1298 | if (x.rlim_cur > 0x7FFFFFFF) |
| 1299 | x.rlim_cur = 0x7FFFFFFF; |
| 1300 | if (x.rlim_max > 0x7FFFFFFF) |
| 1301 | x.rlim_max = 0x7FFFFFFF; |
| 1302 | return copy_to_user(rlim, &x, sizeof(x))?-EFAULT:0; |
| 1303 | } |
| 1304 | |
| 1305 | #endif |
| 1306 | |
| 1307 | static inline bool rlim64_is_infinity(__u64 rlim64) |
| 1308 | { |
| 1309 | #if BITS_PER_LONG < 64 |
| 1310 | return rlim64 >= ULONG_MAX; |
| 1311 | #else |
| 1312 | return rlim64 == RLIM64_INFINITY; |
| 1313 | #endif |
| 1314 | } |
| 1315 | |
| 1316 | static void rlim_to_rlim64(const struct rlimit *rlim, struct rlimit64 *rlim64) |
| 1317 | { |
| 1318 | if (rlim->rlim_cur == RLIM_INFINITY) |
| 1319 | rlim64->rlim_cur = RLIM64_INFINITY; |
| 1320 | else |
| 1321 | rlim64->rlim_cur = rlim->rlim_cur; |
| 1322 | if (rlim->rlim_max == RLIM_INFINITY) |
| 1323 | rlim64->rlim_max = RLIM64_INFINITY; |
| 1324 | else |
| 1325 | rlim64->rlim_max = rlim->rlim_max; |
| 1326 | } |
| 1327 | |
| 1328 | static void rlim64_to_rlim(const struct rlimit64 *rlim64, struct rlimit *rlim) |
| 1329 | { |
| 1330 | if (rlim64_is_infinity(rlim64->rlim_cur)) |
| 1331 | rlim->rlim_cur = RLIM_INFINITY; |
| 1332 | else |
| 1333 | rlim->rlim_cur = (unsigned long)rlim64->rlim_cur; |
| 1334 | if (rlim64_is_infinity(rlim64->rlim_max)) |
| 1335 | rlim->rlim_max = RLIM_INFINITY; |
| 1336 | else |
| 1337 | rlim->rlim_max = (unsigned long)rlim64->rlim_max; |
| 1338 | } |
| 1339 | |
| 1340 | /* make sure you are allowed to change @tsk limits before calling this */ |
| 1341 | int do_prlimit(struct task_struct *tsk, unsigned int resource, |
| 1342 | struct rlimit *new_rlim, struct rlimit *old_rlim) |
| 1343 | { |
| 1344 | struct rlimit *rlim; |
| 1345 | int retval = 0; |
| 1346 | |
| 1347 | if (resource >= RLIM_NLIMITS) |
| 1348 | return -EINVAL; |
| 1349 | if (new_rlim) { |
| 1350 | if (new_rlim->rlim_cur > new_rlim->rlim_max) |
| 1351 | return -EINVAL; |
| 1352 | if (resource == RLIMIT_NOFILE && |
| 1353 | new_rlim->rlim_max > sysctl_nr_open) |
| 1354 | return -EPERM; |
| 1355 | } |
| 1356 | |
| 1357 | /* protect tsk->signal and tsk->sighand from disappearing */ |
| 1358 | read_lock(&tasklist_lock); |
| 1359 | if (!tsk->sighand) { |
| 1360 | retval = -ESRCH; |
| 1361 | goto out; |
| 1362 | } |
| 1363 | |
| 1364 | rlim = tsk->signal->rlim + resource; |
| 1365 | task_lock(tsk->group_leader); |
| 1366 | if (new_rlim) { |
| 1367 | /* Keep the capable check against init_user_ns until |
| 1368 | cgroups can contain all limits */ |
| 1369 | if (new_rlim->rlim_max > rlim->rlim_max && |
| 1370 | !capable(CAP_SYS_RESOURCE)) |
| 1371 | retval = -EPERM; |
| 1372 | if (!retval) |
| 1373 | retval = security_task_setrlimit(tsk->group_leader, |
| 1374 | resource, new_rlim); |
| 1375 | if (resource == RLIMIT_CPU && new_rlim->rlim_cur == 0) { |
| 1376 | /* |
| 1377 | * The caller is asking for an immediate RLIMIT_CPU |
| 1378 | * expiry. But we use the zero value to mean "it was |
| 1379 | * never set". So let's cheat and make it one second |
| 1380 | * instead |
| 1381 | */ |
| 1382 | new_rlim->rlim_cur = 1; |
| 1383 | } |
| 1384 | } |
| 1385 | if (!retval) { |
| 1386 | if (old_rlim) |
| 1387 | *old_rlim = *rlim; |
| 1388 | if (new_rlim) |
| 1389 | *rlim = *new_rlim; |
| 1390 | } |
| 1391 | task_unlock(tsk->group_leader); |
| 1392 | |
| 1393 | /* |
| 1394 | * RLIMIT_CPU handling. Note that the kernel fails to return an error |
| 1395 | * code if it rejected the user's attempt to set RLIMIT_CPU. This is a |
| 1396 | * very long-standing error, and fixing it now risks breakage of |
| 1397 | * applications, so we live with it |
| 1398 | */ |
| 1399 | if (!retval && new_rlim && resource == RLIMIT_CPU && |
| 1400 | new_rlim->rlim_cur != RLIM_INFINITY) |
| 1401 | update_rlimit_cpu(tsk, new_rlim->rlim_cur); |
| 1402 | out: |
| 1403 | read_unlock(&tasklist_lock); |
| 1404 | return retval; |
| 1405 | } |
| 1406 | |
| 1407 | /* rcu lock must be held */ |
| 1408 | static int check_prlimit_permission(struct task_struct *task) |
| 1409 | { |
| 1410 | const struct cred *cred = current_cred(), *tcred; |
| 1411 | |
| 1412 | if (current == task) |
| 1413 | return 0; |
| 1414 | |
| 1415 | tcred = __task_cred(task); |
| 1416 | if (uid_eq(cred->uid, tcred->euid) && |
| 1417 | uid_eq(cred->uid, tcred->suid) && |
| 1418 | uid_eq(cred->uid, tcred->uid) && |
| 1419 | gid_eq(cred->gid, tcred->egid) && |
| 1420 | gid_eq(cred->gid, tcred->sgid) && |
| 1421 | gid_eq(cred->gid, tcred->gid)) |
| 1422 | return 0; |
| 1423 | if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) |
| 1424 | return 0; |
| 1425 | |
| 1426 | return -EPERM; |
| 1427 | } |
| 1428 | |
| 1429 | SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, |
| 1430 | const struct rlimit64 __user *, new_rlim, |
| 1431 | struct rlimit64 __user *, old_rlim) |
| 1432 | { |
| 1433 | struct rlimit64 old64, new64; |
| 1434 | struct rlimit old, new; |
| 1435 | struct task_struct *tsk; |
| 1436 | int ret; |
| 1437 | |
| 1438 | if (new_rlim) { |
| 1439 | if (copy_from_user(&new64, new_rlim, sizeof(new64))) |
| 1440 | return -EFAULT; |
| 1441 | rlim64_to_rlim(&new64, &new); |
| 1442 | } |
| 1443 | |
| 1444 | rcu_read_lock(); |
| 1445 | tsk = pid ? find_task_by_vpid(pid) : current; |
| 1446 | if (!tsk) { |
| 1447 | rcu_read_unlock(); |
| 1448 | return -ESRCH; |
| 1449 | } |
| 1450 | ret = check_prlimit_permission(tsk); |
| 1451 | if (ret) { |
| 1452 | rcu_read_unlock(); |
| 1453 | return ret; |
| 1454 | } |
| 1455 | get_task_struct(tsk); |
| 1456 | rcu_read_unlock(); |
| 1457 | |
| 1458 | ret = do_prlimit(tsk, resource, new_rlim ? &new : NULL, |
| 1459 | old_rlim ? &old : NULL); |
| 1460 | |
| 1461 | if (!ret && old_rlim) { |
| 1462 | rlim_to_rlim64(&old, &old64); |
| 1463 | if (copy_to_user(old_rlim, &old64, sizeof(old64))) |
| 1464 | ret = -EFAULT; |
| 1465 | } |
| 1466 | |
| 1467 | put_task_struct(tsk); |
| 1468 | return ret; |
| 1469 | } |
| 1470 | |
| 1471 | SYSCALL_DEFINE2(setrlimit, unsigned int, resource, struct rlimit __user *, rlim) |
| 1472 | { |
| 1473 | struct rlimit new_rlim; |
| 1474 | |
| 1475 | if (copy_from_user(&new_rlim, rlim, sizeof(*rlim))) |
| 1476 | return -EFAULT; |
| 1477 | return do_prlimit(current, resource, &new_rlim, NULL); |
| 1478 | } |
| 1479 | |
| 1480 | /* |
| 1481 | * It would make sense to put struct rusage in the task_struct, |
| 1482 | * except that would make the task_struct be *really big*. After |
| 1483 | * task_struct gets moved into malloc'ed memory, it would |
| 1484 | * make sense to do this. It will make moving the rest of the information |
| 1485 | * a lot simpler! (Which we're not doing right now because we're not |
| 1486 | * measuring them yet). |
| 1487 | * |
| 1488 | * When sampling multiple threads for RUSAGE_SELF, under SMP we might have |
| 1489 | * races with threads incrementing their own counters. But since word |
| 1490 | * reads are atomic, we either get new values or old values and we don't |
| 1491 | * care which for the sums. We always take the siglock to protect reading |
| 1492 | * the c* fields from p->signal from races with exit.c updating those |
| 1493 | * fields when reaping, so a sample either gets all the additions of a |
| 1494 | * given child after it's reaped, or none so this sample is before reaping. |
| 1495 | * |
| 1496 | * Locking: |
| 1497 | * We need to take the siglock for CHILDEREN, SELF and BOTH |
| 1498 | * for the cases current multithreaded, non-current single threaded |
| 1499 | * non-current multithreaded. Thread traversal is now safe with |
| 1500 | * the siglock held. |
| 1501 | * Strictly speaking, we donot need to take the siglock if we are current and |
| 1502 | * single threaded, as no one else can take our signal_struct away, no one |
| 1503 | * else can reap the children to update signal->c* counters, and no one else |
| 1504 | * can race with the signal-> fields. If we do not take any lock, the |
| 1505 | * signal-> fields could be read out of order while another thread was just |
| 1506 | * exiting. So we should place a read memory barrier when we avoid the lock. |
| 1507 | * On the writer side, write memory barrier is implied in __exit_signal |
| 1508 | * as __exit_signal releases the siglock spinlock after updating the signal-> |
| 1509 | * fields. But we don't do this yet to keep things simple. |
| 1510 | * |
| 1511 | */ |
| 1512 | |
| 1513 | static void accumulate_thread_rusage(struct task_struct *t, struct rusage *r) |
| 1514 | { |
| 1515 | r->ru_nvcsw += t->nvcsw; |
| 1516 | r->ru_nivcsw += t->nivcsw; |
| 1517 | r->ru_minflt += t->min_flt; |
| 1518 | r->ru_majflt += t->maj_flt; |
| 1519 | r->ru_inblock += task_io_get_inblock(t); |
| 1520 | r->ru_oublock += task_io_get_oublock(t); |
| 1521 | } |
| 1522 | |
| 1523 | static void k_getrusage(struct task_struct *p, int who, struct rusage *r) |
| 1524 | { |
| 1525 | struct task_struct *t; |
| 1526 | unsigned long flags; |
| 1527 | cputime_t tgutime, tgstime, utime, stime; |
| 1528 | unsigned long maxrss = 0; |
| 1529 | |
| 1530 | memset((char *) r, 0, sizeof *r); |
| 1531 | utime = stime = 0; |
| 1532 | |
| 1533 | if (who == RUSAGE_THREAD) { |
| 1534 | task_cputime_adjusted(current, &utime, &stime); |
| 1535 | accumulate_thread_rusage(p, r); |
| 1536 | maxrss = p->signal->maxrss; |
| 1537 | goto out; |
| 1538 | } |
| 1539 | |
| 1540 | if (!lock_task_sighand(p, &flags)) |
| 1541 | return; |
| 1542 | |
| 1543 | switch (who) { |
| 1544 | case RUSAGE_BOTH: |
| 1545 | case RUSAGE_CHILDREN: |
| 1546 | utime = p->signal->cutime; |
| 1547 | stime = p->signal->cstime; |
| 1548 | r->ru_nvcsw = p->signal->cnvcsw; |
| 1549 | r->ru_nivcsw = p->signal->cnivcsw; |
| 1550 | r->ru_minflt = p->signal->cmin_flt; |
| 1551 | r->ru_majflt = p->signal->cmaj_flt; |
| 1552 | r->ru_inblock = p->signal->cinblock; |
| 1553 | r->ru_oublock = p->signal->coublock; |
| 1554 | maxrss = p->signal->cmaxrss; |
| 1555 | |
| 1556 | if (who == RUSAGE_CHILDREN) |
| 1557 | break; |
| 1558 | |
| 1559 | case RUSAGE_SELF: |
| 1560 | thread_group_cputime_adjusted(p, &tgutime, &tgstime); |
| 1561 | utime += tgutime; |
| 1562 | stime += tgstime; |
| 1563 | r->ru_nvcsw += p->signal->nvcsw; |
| 1564 | r->ru_nivcsw += p->signal->nivcsw; |
| 1565 | r->ru_minflt += p->signal->min_flt; |
| 1566 | r->ru_majflt += p->signal->maj_flt; |
| 1567 | r->ru_inblock += p->signal->inblock; |
| 1568 | r->ru_oublock += p->signal->oublock; |
| 1569 | if (maxrss < p->signal->maxrss) |
| 1570 | maxrss = p->signal->maxrss; |
| 1571 | t = p; |
| 1572 | do { |
| 1573 | accumulate_thread_rusage(t, r); |
| 1574 | } while_each_thread(p, t); |
| 1575 | break; |
| 1576 | |
| 1577 | default: |
| 1578 | BUG(); |
| 1579 | } |
| 1580 | unlock_task_sighand(p, &flags); |
| 1581 | |
| 1582 | out: |
| 1583 | cputime_to_timeval(utime, &r->ru_utime); |
| 1584 | cputime_to_timeval(stime, &r->ru_stime); |
| 1585 | |
| 1586 | if (who != RUSAGE_CHILDREN) { |
| 1587 | struct mm_struct *mm = get_task_mm(p); |
| 1588 | if (mm) { |
| 1589 | setmax_mm_hiwater_rss(&maxrss, mm); |
| 1590 | mmput(mm); |
| 1591 | } |
| 1592 | } |
| 1593 | r->ru_maxrss = maxrss * (PAGE_SIZE / 1024); /* convert pages to KBs */ |
| 1594 | } |
| 1595 | |
| 1596 | int getrusage(struct task_struct *p, int who, struct rusage __user *ru) |
| 1597 | { |
| 1598 | struct rusage r; |
| 1599 | k_getrusage(p, who, &r); |
| 1600 | return copy_to_user(ru, &r, sizeof(r)) ? -EFAULT : 0; |
| 1601 | } |
| 1602 | |
| 1603 | SYSCALL_DEFINE2(getrusage, int, who, struct rusage __user *, ru) |
| 1604 | { |
| 1605 | if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && |
| 1606 | who != RUSAGE_THREAD) |
| 1607 | return -EINVAL; |
| 1608 | return getrusage(current, who, ru); |
| 1609 | } |
| 1610 | |
| 1611 | #ifdef CONFIG_COMPAT |
| 1612 | COMPAT_SYSCALL_DEFINE2(getrusage, int, who, struct compat_rusage __user *, ru) |
| 1613 | { |
| 1614 | struct rusage r; |
| 1615 | |
| 1616 | if (who != RUSAGE_SELF && who != RUSAGE_CHILDREN && |
| 1617 | who != RUSAGE_THREAD) |
| 1618 | return -EINVAL; |
| 1619 | |
| 1620 | k_getrusage(current, who, &r); |
| 1621 | return put_compat_rusage(&r, ru); |
| 1622 | } |
| 1623 | #endif |
| 1624 | |
| 1625 | SYSCALL_DEFINE1(umask, int, mask) |
| 1626 | { |
| 1627 | mask = xchg(¤t->fs->umask, mask & S_IRWXUGO); |
| 1628 | return mask; |
| 1629 | } |
| 1630 | |
| 1631 | static int prctl_set_mm_exe_file(struct mm_struct *mm, unsigned int fd) |
| 1632 | { |
| 1633 | struct fd exe; |
| 1634 | struct inode *inode; |
| 1635 | int err; |
| 1636 | |
| 1637 | exe = fdget(fd); |
| 1638 | if (!exe.file) |
| 1639 | return -EBADF; |
| 1640 | |
| 1641 | inode = file_inode(exe.file); |
| 1642 | |
| 1643 | /* |
| 1644 | * Because the original mm->exe_file points to executable file, make |
| 1645 | * sure that this one is executable as well, to avoid breaking an |
| 1646 | * overall picture. |
| 1647 | */ |
| 1648 | err = -EACCES; |
| 1649 | if (!S_ISREG(inode->i_mode) || |
| 1650 | exe.file->f_path.mnt->mnt_flags & MNT_NOEXEC) |
| 1651 | goto exit; |
| 1652 | |
| 1653 | err = inode_permission(inode, MAY_EXEC); |
| 1654 | if (err) |
| 1655 | goto exit; |
| 1656 | |
| 1657 | down_write(&mm->mmap_sem); |
| 1658 | |
| 1659 | /* |
| 1660 | * Forbid mm->exe_file change if old file still mapped. |
| 1661 | */ |
| 1662 | err = -EBUSY; |
| 1663 | if (mm->exe_file) { |
| 1664 | struct vm_area_struct *vma; |
| 1665 | |
| 1666 | for (vma = mm->mmap; vma; vma = vma->vm_next) |
| 1667 | if (vma->vm_file && |
| 1668 | path_equal(&vma->vm_file->f_path, |
| 1669 | &mm->exe_file->f_path)) |
| 1670 | goto exit_unlock; |
| 1671 | } |
| 1672 | |
| 1673 | /* |
| 1674 | * The symlink can be changed only once, just to disallow arbitrary |
| 1675 | * transitions malicious software might bring in. This means one |
| 1676 | * could make a snapshot over all processes running and monitor |
| 1677 | * /proc/pid/exe changes to notice unusual activity if needed. |
| 1678 | */ |
| 1679 | err = -EPERM; |
| 1680 | if (test_and_set_bit(MMF_EXE_FILE_CHANGED, &mm->flags)) |
| 1681 | goto exit_unlock; |
| 1682 | |
| 1683 | err = 0; |
| 1684 | set_mm_exe_file(mm, exe.file); /* this grabs a reference to exe.file */ |
| 1685 | exit_unlock: |
| 1686 | up_write(&mm->mmap_sem); |
| 1687 | |
| 1688 | exit: |
| 1689 | fdput(exe); |
| 1690 | return err; |
| 1691 | } |
| 1692 | |
| 1693 | static int prctl_set_mm(int opt, unsigned long addr, |
| 1694 | unsigned long arg4, unsigned long arg5) |
| 1695 | { |
| 1696 | unsigned long rlim = rlimit(RLIMIT_DATA); |
| 1697 | struct mm_struct *mm = current->mm; |
| 1698 | struct vm_area_struct *vma; |
| 1699 | int error; |
| 1700 | |
| 1701 | if (arg5 || (arg4 && opt != PR_SET_MM_AUXV)) |
| 1702 | return -EINVAL; |
| 1703 | |
| 1704 | if (!capable(CAP_SYS_RESOURCE)) |
| 1705 | return -EPERM; |
| 1706 | |
| 1707 | if (opt == PR_SET_MM_EXE_FILE) |
| 1708 | return prctl_set_mm_exe_file(mm, (unsigned int)addr); |
| 1709 | |
| 1710 | if (addr >= TASK_SIZE || addr < mmap_min_addr) |
| 1711 | return -EINVAL; |
| 1712 | |
| 1713 | error = -EINVAL; |
| 1714 | |
| 1715 | down_read(&mm->mmap_sem); |
| 1716 | vma = find_vma(mm, addr); |
| 1717 | |
| 1718 | switch (opt) { |
| 1719 | case PR_SET_MM_START_CODE: |
| 1720 | mm->start_code = addr; |
| 1721 | break; |
| 1722 | case PR_SET_MM_END_CODE: |
| 1723 | mm->end_code = addr; |
| 1724 | break; |
| 1725 | case PR_SET_MM_START_DATA: |
| 1726 | mm->start_data = addr; |
| 1727 | break; |
| 1728 | case PR_SET_MM_END_DATA: |
| 1729 | mm->end_data = addr; |
| 1730 | break; |
| 1731 | |
| 1732 | case PR_SET_MM_START_BRK: |
| 1733 | if (addr <= mm->end_data) |
| 1734 | goto out; |
| 1735 | |
| 1736 | if (rlim < RLIM_INFINITY && |
| 1737 | (mm->brk - addr) + |
| 1738 | (mm->end_data - mm->start_data) > rlim) |
| 1739 | goto out; |
| 1740 | |
| 1741 | mm->start_brk = addr; |
| 1742 | break; |
| 1743 | |
| 1744 | case PR_SET_MM_BRK: |
| 1745 | if (addr <= mm->end_data) |
| 1746 | goto out; |
| 1747 | |
| 1748 | if (rlim < RLIM_INFINITY && |
| 1749 | (addr - mm->start_brk) + |
| 1750 | (mm->end_data - mm->start_data) > rlim) |
| 1751 | goto out; |
| 1752 | |
| 1753 | mm->brk = addr; |
| 1754 | break; |
| 1755 | |
| 1756 | /* |
| 1757 | * If command line arguments and environment |
| 1758 | * are placed somewhere else on stack, we can |
| 1759 | * set them up here, ARG_START/END to setup |
| 1760 | * command line argumets and ENV_START/END |
| 1761 | * for environment. |
| 1762 | */ |
| 1763 | case PR_SET_MM_START_STACK: |
| 1764 | case PR_SET_MM_ARG_START: |
| 1765 | case PR_SET_MM_ARG_END: |
| 1766 | case PR_SET_MM_ENV_START: |
| 1767 | case PR_SET_MM_ENV_END: |
| 1768 | if (!vma) { |
| 1769 | error = -EFAULT; |
| 1770 | goto out; |
| 1771 | } |
| 1772 | if (opt == PR_SET_MM_START_STACK) |
| 1773 | mm->start_stack = addr; |
| 1774 | else if (opt == PR_SET_MM_ARG_START) |
| 1775 | mm->arg_start = addr; |
| 1776 | else if (opt == PR_SET_MM_ARG_END) |
| 1777 | mm->arg_end = addr; |
| 1778 | else if (opt == PR_SET_MM_ENV_START) |
| 1779 | mm->env_start = addr; |
| 1780 | else if (opt == PR_SET_MM_ENV_END) |
| 1781 | mm->env_end = addr; |
| 1782 | break; |
| 1783 | |
| 1784 | /* |
| 1785 | * This doesn't move auxiliary vector itself |
| 1786 | * since it's pinned to mm_struct, but allow |
| 1787 | * to fill vector with new values. It's up |
| 1788 | * to a caller to provide sane values here |
| 1789 | * otherwise user space tools which use this |
| 1790 | * vector might be unhappy. |
| 1791 | */ |
| 1792 | case PR_SET_MM_AUXV: { |
| 1793 | unsigned long user_auxv[AT_VECTOR_SIZE]; |
| 1794 | |
| 1795 | if (arg4 > sizeof(user_auxv)) |
| 1796 | goto out; |
| 1797 | up_read(&mm->mmap_sem); |
| 1798 | |
| 1799 | if (copy_from_user(user_auxv, (const void __user *)addr, arg4)) |
| 1800 | return -EFAULT; |
| 1801 | |
| 1802 | /* Make sure the last entry is always AT_NULL */ |
| 1803 | user_auxv[AT_VECTOR_SIZE - 2] = 0; |
| 1804 | user_auxv[AT_VECTOR_SIZE - 1] = 0; |
| 1805 | |
| 1806 | BUILD_BUG_ON(sizeof(user_auxv) != sizeof(mm->saved_auxv)); |
| 1807 | |
| 1808 | task_lock(current); |
| 1809 | memcpy(mm->saved_auxv, user_auxv, arg4); |
| 1810 | task_unlock(current); |
| 1811 | |
| 1812 | return 0; |
| 1813 | } |
| 1814 | default: |
| 1815 | goto out; |
| 1816 | } |
| 1817 | |
| 1818 | error = 0; |
| 1819 | out: |
| 1820 | up_read(&mm->mmap_sem); |
| 1821 | return error; |
| 1822 | } |
| 1823 | |
| 1824 | #ifdef CONFIG_CHECKPOINT_RESTORE |
| 1825 | static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) |
| 1826 | { |
| 1827 | return put_user(me->clear_child_tid, tid_addr); |
| 1828 | } |
| 1829 | #else |
| 1830 | static int prctl_get_tid_address(struct task_struct *me, int __user **tid_addr) |
| 1831 | { |
| 1832 | return -EINVAL; |
| 1833 | } |
| 1834 | #endif |
| 1835 | |
| 1836 | SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, |
| 1837 | unsigned long, arg4, unsigned long, arg5) |
| 1838 | { |
| 1839 | struct task_struct *me = current; |
| 1840 | unsigned char comm[sizeof(me->comm)]; |
| 1841 | long error; |
| 1842 | |
| 1843 | error = security_task_prctl(option, arg2, arg3, arg4, arg5); |
| 1844 | if (error != -ENOSYS) |
| 1845 | return error; |
| 1846 | |
| 1847 | error = 0; |
| 1848 | switch (option) { |
| 1849 | case PR_SET_PDEATHSIG: |
| 1850 | if (!valid_signal(arg2)) { |
| 1851 | error = -EINVAL; |
| 1852 | break; |
| 1853 | } |
| 1854 | me->pdeath_signal = arg2; |
| 1855 | break; |
| 1856 | case PR_GET_PDEATHSIG: |
| 1857 | error = put_user(me->pdeath_signal, (int __user *)arg2); |
| 1858 | break; |
| 1859 | case PR_GET_DUMPABLE: |
| 1860 | error = get_dumpable(me->mm); |
| 1861 | break; |
| 1862 | case PR_SET_DUMPABLE: |
| 1863 | if (arg2 != SUID_DUMP_DISABLE && arg2 != SUID_DUMP_USER) { |
| 1864 | error = -EINVAL; |
| 1865 | break; |
| 1866 | } |
| 1867 | set_dumpable(me->mm, arg2); |
| 1868 | break; |
| 1869 | |
| 1870 | case PR_SET_UNALIGN: |
| 1871 | error = SET_UNALIGN_CTL(me, arg2); |
| 1872 | break; |
| 1873 | case PR_GET_UNALIGN: |
| 1874 | error = GET_UNALIGN_CTL(me, arg2); |
| 1875 | break; |
| 1876 | case PR_SET_FPEMU: |
| 1877 | error = SET_FPEMU_CTL(me, arg2); |
| 1878 | break; |
| 1879 | case PR_GET_FPEMU: |
| 1880 | error = GET_FPEMU_CTL(me, arg2); |
| 1881 | break; |
| 1882 | case PR_SET_FPEXC: |
| 1883 | error = SET_FPEXC_CTL(me, arg2); |
| 1884 | break; |
| 1885 | case PR_GET_FPEXC: |
| 1886 | error = GET_FPEXC_CTL(me, arg2); |
| 1887 | break; |
| 1888 | case PR_GET_TIMING: |
| 1889 | error = PR_TIMING_STATISTICAL; |
| 1890 | break; |
| 1891 | case PR_SET_TIMING: |
| 1892 | if (arg2 != PR_TIMING_STATISTICAL) |
| 1893 | error = -EINVAL; |
| 1894 | break; |
| 1895 | case PR_SET_NAME: |
| 1896 | comm[sizeof(me->comm) - 1] = 0; |
| 1897 | if (strncpy_from_user(comm, (char __user *)arg2, |
| 1898 | sizeof(me->comm) - 1) < 0) |
| 1899 | return -EFAULT; |
| 1900 | set_task_comm(me, comm); |
| 1901 | proc_comm_connector(me); |
| 1902 | break; |
| 1903 | case PR_GET_NAME: |
| 1904 | get_task_comm(comm, me); |
| 1905 | if (copy_to_user((char __user *)arg2, comm, sizeof(comm))) |
| 1906 | return -EFAULT; |
| 1907 | break; |
| 1908 | case PR_GET_ENDIAN: |
| 1909 | error = GET_ENDIAN(me, arg2); |
| 1910 | break; |
| 1911 | case PR_SET_ENDIAN: |
| 1912 | error = SET_ENDIAN(me, arg2); |
| 1913 | break; |
| 1914 | case PR_GET_SECCOMP: |
| 1915 | error = prctl_get_seccomp(); |
| 1916 | break; |
| 1917 | case PR_SET_SECCOMP: |
| 1918 | error = prctl_set_seccomp(arg2, (char __user *)arg3); |
| 1919 | break; |
| 1920 | case PR_GET_TSC: |
| 1921 | error = GET_TSC_CTL(arg2); |
| 1922 | break; |
| 1923 | case PR_SET_TSC: |
| 1924 | error = SET_TSC_CTL(arg2); |
| 1925 | break; |
| 1926 | case PR_TASK_PERF_EVENTS_DISABLE: |
| 1927 | error = perf_event_task_disable(); |
| 1928 | break; |
| 1929 | case PR_TASK_PERF_EVENTS_ENABLE: |
| 1930 | error = perf_event_task_enable(); |
| 1931 | break; |
| 1932 | case PR_GET_TIMERSLACK: |
| 1933 | error = current->timer_slack_ns; |
| 1934 | break; |
| 1935 | case PR_SET_TIMERSLACK: |
| 1936 | if (arg2 <= 0) |
| 1937 | current->timer_slack_ns = |
| 1938 | current->default_timer_slack_ns; |
| 1939 | else |
| 1940 | current->timer_slack_ns = arg2; |
| 1941 | break; |
| 1942 | case PR_MCE_KILL: |
| 1943 | if (arg4 | arg5) |
| 1944 | return -EINVAL; |
| 1945 | switch (arg2) { |
| 1946 | case PR_MCE_KILL_CLEAR: |
| 1947 | if (arg3 != 0) |
| 1948 | return -EINVAL; |
| 1949 | current->flags &= ~PF_MCE_PROCESS; |
| 1950 | break; |
| 1951 | case PR_MCE_KILL_SET: |
| 1952 | current->flags |= PF_MCE_PROCESS; |
| 1953 | if (arg3 == PR_MCE_KILL_EARLY) |
| 1954 | current->flags |= PF_MCE_EARLY; |
| 1955 | else if (arg3 == PR_MCE_KILL_LATE) |
| 1956 | current->flags &= ~PF_MCE_EARLY; |
| 1957 | else if (arg3 == PR_MCE_KILL_DEFAULT) |
| 1958 | current->flags &= |
| 1959 | ~(PF_MCE_EARLY|PF_MCE_PROCESS); |
| 1960 | else |
| 1961 | return -EINVAL; |
| 1962 | break; |
| 1963 | default: |
| 1964 | return -EINVAL; |
| 1965 | } |
| 1966 | break; |
| 1967 | case PR_MCE_KILL_GET: |
| 1968 | if (arg2 | arg3 | arg4 | arg5) |
| 1969 | return -EINVAL; |
| 1970 | if (current->flags & PF_MCE_PROCESS) |
| 1971 | error = (current->flags & PF_MCE_EARLY) ? |
| 1972 | PR_MCE_KILL_EARLY : PR_MCE_KILL_LATE; |
| 1973 | else |
| 1974 | error = PR_MCE_KILL_DEFAULT; |
| 1975 | break; |
| 1976 | case PR_SET_MM: |
| 1977 | error = prctl_set_mm(arg2, arg3, arg4, arg5); |
| 1978 | break; |
| 1979 | case PR_GET_TID_ADDRESS: |
| 1980 | error = prctl_get_tid_address(me, (int __user **)arg2); |
| 1981 | break; |
| 1982 | case PR_SET_CHILD_SUBREAPER: |
| 1983 | me->signal->is_child_subreaper = !!arg2; |
| 1984 | break; |
| 1985 | case PR_GET_CHILD_SUBREAPER: |
| 1986 | error = put_user(me->signal->is_child_subreaper, |
| 1987 | (int __user *)arg2); |
| 1988 | break; |
| 1989 | case PR_SET_NO_NEW_PRIVS: |
| 1990 | if (arg2 != 1 || arg3 || arg4 || arg5) |
| 1991 | return -EINVAL; |
| 1992 | |
| 1993 | current->no_new_privs = 1; |
| 1994 | break; |
| 1995 | case PR_GET_NO_NEW_PRIVS: |
| 1996 | if (arg2 || arg3 || arg4 || arg5) |
| 1997 | return -EINVAL; |
| 1998 | return current->no_new_privs ? 1 : 0; |
| 1999 | default: |
| 2000 | error = -EINVAL; |
| 2001 | break; |
| 2002 | } |
| 2003 | return error; |
| 2004 | } |
| 2005 | |
| 2006 | SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, |
| 2007 | struct getcpu_cache __user *, unused) |
| 2008 | { |
| 2009 | int err = 0; |
| 2010 | int cpu = raw_smp_processor_id(); |
| 2011 | if (cpup) |
| 2012 | err |= put_user(cpu, cpup); |
| 2013 | if (nodep) |
| 2014 | err |= put_user(cpu_to_node(cpu), nodep); |
| 2015 | return err ? -EFAULT : 0; |
| 2016 | } |
| 2017 | |
| 2018 | /** |
| 2019 | * do_sysinfo - fill in sysinfo struct |
| 2020 | * @info: pointer to buffer to fill |
| 2021 | */ |
| 2022 | static int do_sysinfo(struct sysinfo *info) |
| 2023 | { |
| 2024 | unsigned long mem_total, sav_total; |
| 2025 | unsigned int mem_unit, bitcount; |
| 2026 | struct timespec tp; |
| 2027 | |
| 2028 | memset(info, 0, sizeof(struct sysinfo)); |
| 2029 | |
| 2030 | get_monotonic_boottime(&tp); |
| 2031 | info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0); |
| 2032 | |
| 2033 | get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT); |
| 2034 | |
| 2035 | info->procs = nr_threads; |
| 2036 | |
| 2037 | si_meminfo(info); |
| 2038 | si_swapinfo(info); |
| 2039 | |
| 2040 | /* |
| 2041 | * If the sum of all the available memory (i.e. ram + swap) |
| 2042 | * is less than can be stored in a 32 bit unsigned long then |
| 2043 | * we can be binary compatible with 2.2.x kernels. If not, |
| 2044 | * well, in that case 2.2.x was broken anyways... |
| 2045 | * |
| 2046 | * -Erik Andersen <andersee@debian.org> |
| 2047 | */ |
| 2048 | |
| 2049 | mem_total = info->totalram + info->totalswap; |
| 2050 | if (mem_total < info->totalram || mem_total < info->totalswap) |
| 2051 | goto out; |
| 2052 | bitcount = 0; |
| 2053 | mem_unit = info->mem_unit; |
| 2054 | while (mem_unit > 1) { |
| 2055 | bitcount++; |
| 2056 | mem_unit >>= 1; |
| 2057 | sav_total = mem_total; |
| 2058 | mem_total <<= 1; |
| 2059 | if (mem_total < sav_total) |
| 2060 | goto out; |
| 2061 | } |
| 2062 | |
| 2063 | /* |
| 2064 | * If mem_total did not overflow, multiply all memory values by |
| 2065 | * info->mem_unit and set it to 1. This leaves things compatible |
| 2066 | * with 2.2.x, and also retains compatibility with earlier 2.4.x |
| 2067 | * kernels... |
| 2068 | */ |
| 2069 | |
| 2070 | info->mem_unit = 1; |
| 2071 | info->totalram <<= bitcount; |
| 2072 | info->freeram <<= bitcount; |
| 2073 | info->sharedram <<= bitcount; |
| 2074 | info->bufferram <<= bitcount; |
| 2075 | info->totalswap <<= bitcount; |
| 2076 | info->freeswap <<= bitcount; |
| 2077 | info->totalhigh <<= bitcount; |
| 2078 | info->freehigh <<= bitcount; |
| 2079 | |
| 2080 | out: |
| 2081 | return 0; |
| 2082 | } |
| 2083 | |
| 2084 | SYSCALL_DEFINE1(sysinfo, struct sysinfo __user *, info) |
| 2085 | { |
| 2086 | struct sysinfo val; |
| 2087 | |
| 2088 | do_sysinfo(&val); |
| 2089 | |
| 2090 | if (copy_to_user(info, &val, sizeof(struct sysinfo))) |
| 2091 | return -EFAULT; |
| 2092 | |
| 2093 | return 0; |
| 2094 | } |
| 2095 | |
| 2096 | #ifdef CONFIG_COMPAT |
| 2097 | struct compat_sysinfo { |
| 2098 | s32 uptime; |
| 2099 | u32 loads[3]; |
| 2100 | u32 totalram; |
| 2101 | u32 freeram; |
| 2102 | u32 sharedram; |
| 2103 | u32 bufferram; |
| 2104 | u32 totalswap; |
| 2105 | u32 freeswap; |
| 2106 | u16 procs; |
| 2107 | u16 pad; |
| 2108 | u32 totalhigh; |
| 2109 | u32 freehigh; |
| 2110 | u32 mem_unit; |
| 2111 | char _f[20-2*sizeof(u32)-sizeof(int)]; |
| 2112 | }; |
| 2113 | |
| 2114 | COMPAT_SYSCALL_DEFINE1(sysinfo, struct compat_sysinfo __user *, info) |
| 2115 | { |
| 2116 | struct sysinfo s; |
| 2117 | |
| 2118 | do_sysinfo(&s); |
| 2119 | |
| 2120 | /* Check to see if any memory value is too large for 32-bit and scale |
| 2121 | * down if needed |
| 2122 | */ |
| 2123 | if ((s.totalram >> 32) || (s.totalswap >> 32)) { |
| 2124 | int bitcount = 0; |
| 2125 | |
| 2126 | while (s.mem_unit < PAGE_SIZE) { |
| 2127 | s.mem_unit <<= 1; |
| 2128 | bitcount++; |
| 2129 | } |
| 2130 | |
| 2131 | s.totalram >>= bitcount; |
| 2132 | s.freeram >>= bitcount; |
| 2133 | s.sharedram >>= bitcount; |
| 2134 | s.bufferram >>= bitcount; |
| 2135 | s.totalswap >>= bitcount; |
| 2136 | s.freeswap >>= bitcount; |
| 2137 | s.totalhigh >>= bitcount; |
| 2138 | s.freehigh >>= bitcount; |
| 2139 | } |
| 2140 | |
| 2141 | if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) || |
| 2142 | __put_user(s.uptime, &info->uptime) || |
| 2143 | __put_user(s.loads[0], &info->loads[0]) || |
| 2144 | __put_user(s.loads[1], &info->loads[1]) || |
| 2145 | __put_user(s.loads[2], &info->loads[2]) || |
| 2146 | __put_user(s.totalram, &info->totalram) || |
| 2147 | __put_user(s.freeram, &info->freeram) || |
| 2148 | __put_user(s.sharedram, &info->sharedram) || |
| 2149 | __put_user(s.bufferram, &info->bufferram) || |
| 2150 | __put_user(s.totalswap, &info->totalswap) || |
| 2151 | __put_user(s.freeswap, &info->freeswap) || |
| 2152 | __put_user(s.procs, &info->procs) || |
| 2153 | __put_user(s.totalhigh, &info->totalhigh) || |
| 2154 | __put_user(s.freehigh, &info->freehigh) || |
| 2155 | __put_user(s.mem_unit, &info->mem_unit)) |
| 2156 | return -EFAULT; |
| 2157 | |
| 2158 | return 0; |
| 2159 | } |
| 2160 | #endif /* CONFIG_COMPAT */ |