1 /* Common capabilities, needed by capability.o. 2 * 3 * This program is free software; you can redistribute it and/or modify 4 * it under the terms of the GNU General Public License as published by 5 * the Free Software Foundation; either version 2 of the License, or 6 * (at your option) any later version. 7 * 8 */ 9 10 #include <linux/capability.h> 11 #include <linux/audit.h> 12 #include <linux/module.h> 13 #include <linux/init.h> 14 #include <linux/kernel.h> 15 #include <linux/lsm_hooks.h> 16 #include <linux/file.h> 17 #include <linux/mm.h> 18 #include <linux/mman.h> 19 #include <linux/pagemap.h> 20 #include <linux/swap.h> 21 #include <linux/skbuff.h> 22 #include <linux/netlink.h> 23 #include <linux/ptrace.h> 24 #include <linux/xattr.h> 25 #include <linux/hugetlb.h> 26 #include <linux/mount.h> 27 #include <linux/sched.h> 28 #include <linux/prctl.h> 29 #include <linux/securebits.h> 30 #include <linux/user_namespace.h> 31 #include <linux/binfmts.h> 32 #include <linux/personality.h> 33 34 /* 35 * If a non-root user executes a setuid-root binary in 36 * !secure(SECURE_NOROOT) mode, then we raise capabilities. 37 * However if fE is also set, then the intent is for only 38 * the file capabilities to be applied, and the setuid-root 39 * bit is left on either to change the uid (plausible) or 40 * to get full privilege on a kernel without file capabilities 41 * support. So in that case we do not raise capabilities. 42 * 43 * Warn if that happens, once per boot. 44 */ 45 static void warn_setuid_and_fcaps_mixed(const char *fname) 46 { 47 static int warned; 48 if (!warned) { 49 printk(KERN_INFO "warning: `%s' has both setuid-root and" 50 " effective capabilities. Therefore not raising all" 51 " capabilities.\n", fname); 52 warned = 1; 53 } 54 } 55 56 /** 57 * cap_capable - Determine whether a task has a particular effective capability 58 * @cred: The credentials to use 59 * @ns: The user namespace in which we need the capability 60 * @cap: The capability to check for 61 * @audit: Whether to write an audit message or not 62 * 63 * Determine whether the nominated task has the specified capability amongst 64 * its effective set, returning 0 if it does, -ve if it does not. 65 * 66 * NOTE WELL: cap_has_capability() cannot be used like the kernel's capable() 67 * and has_capability() functions. That is, it has the reverse semantics: 68 * cap_has_capability() returns 0 when a task has a capability, but the 69 * kernel's capable() and has_capability() returns 1 for this case. 70 */ 71 int cap_capable(const struct cred *cred, struct user_namespace *targ_ns, 72 int cap, int audit) 73 { 74 struct user_namespace *ns = targ_ns; 75 76 /* See if cred has the capability in the target user namespace 77 * by examining the target user namespace and all of the target 78 * user namespace's parents. 79 */ 80 for (;;) { 81 /* Do we have the necessary capabilities? */ 82 if (ns == cred->user_ns) 83 return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM; 84 85 /* 86 * If we're already at a lower level than we're looking for, 87 * we're done searching. 88 */ 89 if (ns->level <= cred->user_ns->level) 90 return -EPERM; 91 92 /* 93 * The owner of the user namespace in the parent of the 94 * user namespace has all caps. 95 */ 96 if ((ns->parent == cred->user_ns) && uid_eq(ns->owner, cred->euid)) 97 return 0; 98 99 /* 100 * If you have a capability in a parent user ns, then you have 101 * it over all children user namespaces as well. 102 */ 103 ns = ns->parent; 104 } 105 106 /* We never get here */ 107 } 108 109 /** 110 * cap_settime - Determine whether the current process may set the system clock 111 * @ts: The time to set 112 * @tz: The timezone to set 113 * 114 * Determine whether the current process may set the system clock and timezone 115 * information, returning 0 if permission granted, -ve if denied. 116 */ 117 int cap_settime(const struct timespec64 *ts, const struct timezone *tz) 118 { 119 if (!capable(CAP_SYS_TIME)) 120 return -EPERM; 121 return 0; 122 } 123 124 /** 125 * cap_ptrace_access_check - Determine whether the current process may access 126 * another 127 * @child: The process to be accessed 128 * @mode: The mode of attachment. 129 * 130 * If we are in the same or an ancestor user_ns and have all the target 131 * task's capabilities, then ptrace access is allowed. 132 * If we have the ptrace capability to the target user_ns, then ptrace 133 * access is allowed. 134 * Else denied. 135 * 136 * Determine whether a process may access another, returning 0 if permission 137 * granted, -ve if denied. 138 */ 139 int cap_ptrace_access_check(struct task_struct *child, unsigned int mode) 140 { 141 int ret = 0; 142 const struct cred *cred, *child_cred; 143 const kernel_cap_t *caller_caps; 144 145 rcu_read_lock(); 146 cred = current_cred(); 147 child_cred = __task_cred(child); 148 if (mode & PTRACE_MODE_FSCREDS) 149 caller_caps = &cred->cap_effective; 150 else 151 caller_caps = &cred->cap_permitted; 152 if (cred->user_ns == child_cred->user_ns && 153 cap_issubset(child_cred->cap_permitted, *caller_caps)) 154 goto out; 155 if (ns_capable(child_cred->user_ns, CAP_SYS_PTRACE)) 156 goto out; 157 ret = -EPERM; 158 out: 159 rcu_read_unlock(); 160 return ret; 161 } 162 163 /** 164 * cap_ptrace_traceme - Determine whether another process may trace the current 165 * @parent: The task proposed to be the tracer 166 * 167 * If parent is in the same or an ancestor user_ns and has all current's 168 * capabilities, then ptrace access is allowed. 169 * If parent has the ptrace capability to current's user_ns, then ptrace 170 * access is allowed. 171 * Else denied. 172 * 173 * Determine whether the nominated task is permitted to trace the current 174 * process, returning 0 if permission is granted, -ve if denied. 175 */ 176 int cap_ptrace_traceme(struct task_struct *parent) 177 { 178 int ret = 0; 179 const struct cred *cred, *child_cred; 180 181 rcu_read_lock(); 182 cred = __task_cred(parent); 183 child_cred = current_cred(); 184 if (cred->user_ns == child_cred->user_ns && 185 cap_issubset(child_cred->cap_permitted, cred->cap_permitted)) 186 goto out; 187 if (has_ns_capability(parent, child_cred->user_ns, CAP_SYS_PTRACE)) 188 goto out; 189 ret = -EPERM; 190 out: 191 rcu_read_unlock(); 192 return ret; 193 } 194 195 /** 196 * cap_capget - Retrieve a task's capability sets 197 * @target: The task from which to retrieve the capability sets 198 * @effective: The place to record the effective set 199 * @inheritable: The place to record the inheritable set 200 * @permitted: The place to record the permitted set 201 * 202 * This function retrieves the capabilities of the nominated task and returns 203 * them to the caller. 204 */ 205 int cap_capget(struct task_struct *target, kernel_cap_t *effective, 206 kernel_cap_t *inheritable, kernel_cap_t *permitted) 207 { 208 const struct cred *cred; 209 210 /* Derived from kernel/capability.c:sys_capget. */ 211 rcu_read_lock(); 212 cred = __task_cred(target); 213 *effective = cred->cap_effective; 214 *inheritable = cred->cap_inheritable; 215 *permitted = cred->cap_permitted; 216 rcu_read_unlock(); 217 return 0; 218 } 219 220 /* 221 * Determine whether the inheritable capabilities are limited to the old 222 * permitted set. Returns 1 if they are limited, 0 if they are not. 223 */ 224 static inline int cap_inh_is_capped(void) 225 { 226 227 /* they are so limited unless the current task has the CAP_SETPCAP 228 * capability 229 */ 230 if (cap_capable(current_cred(), current_cred()->user_ns, 231 CAP_SETPCAP, SECURITY_CAP_AUDIT) == 0) 232 return 0; 233 return 1; 234 } 235 236 /** 237 * cap_capset - Validate and apply proposed changes to current's capabilities 238 * @new: The proposed new credentials; alterations should be made here 239 * @old: The current task's current credentials 240 * @effective: A pointer to the proposed new effective capabilities set 241 * @inheritable: A pointer to the proposed new inheritable capabilities set 242 * @permitted: A pointer to the proposed new permitted capabilities set 243 * 244 * This function validates and applies a proposed mass change to the current 245 * process's capability sets. The changes are made to the proposed new 246 * credentials, and assuming no error, will be committed by the caller of LSM. 247 */ 248 int cap_capset(struct cred *new, 249 const struct cred *old, 250 const kernel_cap_t *effective, 251 const kernel_cap_t *inheritable, 252 const kernel_cap_t *permitted) 253 { 254 if (cap_inh_is_capped() && 255 !cap_issubset(*inheritable, 256 cap_combine(old->cap_inheritable, 257 old->cap_permitted))) 258 /* incapable of using this inheritable set */ 259 return -EPERM; 260 261 if (!cap_issubset(*inheritable, 262 cap_combine(old->cap_inheritable, 263 old->cap_bset))) 264 /* no new pI capabilities outside bounding set */ 265 return -EPERM; 266 267 /* verify restrictions on target's new Permitted set */ 268 if (!cap_issubset(*permitted, old->cap_permitted)) 269 return -EPERM; 270 271 /* verify the _new_Effective_ is a subset of the _new_Permitted_ */ 272 if (!cap_issubset(*effective, *permitted)) 273 return -EPERM; 274 275 new->cap_effective = *effective; 276 new->cap_inheritable = *inheritable; 277 new->cap_permitted = *permitted; 278 279 /* 280 * Mask off ambient bits that are no longer both permitted and 281 * inheritable. 282 */ 283 new->cap_ambient = cap_intersect(new->cap_ambient, 284 cap_intersect(*permitted, 285 *inheritable)); 286 if (WARN_ON(!cap_ambient_invariant_ok(new))) 287 return -EINVAL; 288 return 0; 289 } 290 291 /** 292 * cap_inode_need_killpriv - Determine if inode change affects privileges 293 * @dentry: The inode/dentry in being changed with change marked ATTR_KILL_PRIV 294 * 295 * Determine if an inode having a change applied that's marked ATTR_KILL_PRIV 296 * affects the security markings on that inode, and if it is, should 297 * inode_killpriv() be invoked or the change rejected. 298 * 299 * Returns 1 if security.capability has a value, meaning inode_killpriv() 300 * is required, 0 otherwise, meaning inode_killpriv() is not required. 301 */ 302 int cap_inode_need_killpriv(struct dentry *dentry) 303 { 304 struct inode *inode = d_backing_inode(dentry); 305 int error; 306 307 error = __vfs_getxattr(dentry, inode, XATTR_NAME_CAPS, NULL, 0); 308 return error > 0; 309 } 310 311 /** 312 * cap_inode_killpriv - Erase the security markings on an inode 313 * @dentry: The inode/dentry to alter 314 * 315 * Erase the privilege-enhancing security markings on an inode. 316 * 317 * Returns 0 if successful, -ve on error. 318 */ 319 int cap_inode_killpriv(struct dentry *dentry) 320 { 321 int error; 322 323 error = __vfs_removexattr(dentry, XATTR_NAME_CAPS); 324 if (error == -EOPNOTSUPP) 325 error = 0; 326 return error; 327 } 328 329 static bool rootid_owns_currentns(kuid_t kroot) 330 { 331 struct user_namespace *ns; 332 333 if (!uid_valid(kroot)) 334 return false; 335 336 for (ns = current_user_ns(); ; ns = ns->parent) { 337 if (from_kuid(ns, kroot) == 0) 338 return true; 339 if (ns == &init_user_ns) 340 break; 341 } 342 343 return false; 344 } 345 346 static __u32 sansflags(__u32 m) 347 { 348 return m & ~VFS_CAP_FLAGS_EFFECTIVE; 349 } 350 351 static bool is_v2header(size_t size, const struct vfs_cap_data *cap) 352 { 353 if (size != XATTR_CAPS_SZ_2) 354 return false; 355 return sansflags(le32_to_cpu(cap->magic_etc)) == VFS_CAP_REVISION_2; 356 } 357 358 static bool is_v3header(size_t size, const struct vfs_cap_data *cap) 359 { 360 if (size != XATTR_CAPS_SZ_3) 361 return false; 362 return sansflags(le32_to_cpu(cap->magic_etc)) == VFS_CAP_REVISION_3; 363 } 364 365 /* 366 * getsecurity: We are called for security.* before any attempt to read the 367 * xattr from the inode itself. 368 * 369 * This gives us a chance to read the on-disk value and convert it. If we 370 * return -EOPNOTSUPP, then vfs_getxattr() will call the i_op handler. 371 * 372 * Note we are not called by vfs_getxattr_alloc(), but that is only called 373 * by the integrity subsystem, which really wants the unconverted values - 374 * so that's good. 375 */ 376 int cap_inode_getsecurity(struct inode *inode, const char *name, void **buffer, 377 bool alloc) 378 { 379 int size, ret; 380 kuid_t kroot; 381 uid_t root, mappedroot; 382 char *tmpbuf = NULL; 383 struct vfs_cap_data *cap; 384 struct vfs_ns_cap_data *nscap; 385 struct dentry *dentry; 386 struct user_namespace *fs_ns; 387 388 if (strcmp(name, "capability") != 0) 389 return -EOPNOTSUPP; 390 391 dentry = d_find_any_alias(inode); 392 if (!dentry) 393 return -EINVAL; 394 395 size = sizeof(struct vfs_ns_cap_data); 396 ret = (int) vfs_getxattr_alloc(dentry, XATTR_NAME_CAPS, 397 &tmpbuf, size, GFP_NOFS); 398 dput(dentry); 399 400 if (ret < 0) 401 return ret; 402 403 fs_ns = inode->i_sb->s_user_ns; 404 cap = (struct vfs_cap_data *) tmpbuf; 405 if (is_v2header((size_t) ret, cap)) { 406 /* If this is sizeof(vfs_cap_data) then we're ok with the 407 * on-disk value, so return that. */ 408 if (alloc) 409 *buffer = tmpbuf; 410 else 411 kfree(tmpbuf); 412 return ret; 413 } else if (!is_v3header((size_t) ret, cap)) { 414 kfree(tmpbuf); 415 return -EINVAL; 416 } 417 418 nscap = (struct vfs_ns_cap_data *) tmpbuf; 419 root = le32_to_cpu(nscap->rootid); 420 kroot = make_kuid(fs_ns, root); 421 422 /* If the root kuid maps to a valid uid in current ns, then return 423 * this as a nscap. */ 424 mappedroot = from_kuid(current_user_ns(), kroot); 425 if (mappedroot != (uid_t)-1 && mappedroot != (uid_t)0) { 426 if (alloc) { 427 *buffer = tmpbuf; 428 nscap->rootid = cpu_to_le32(mappedroot); 429 } else 430 kfree(tmpbuf); 431 return size; 432 } 433 434 if (!rootid_owns_currentns(kroot)) { 435 kfree(tmpbuf); 436 return -EOPNOTSUPP; 437 } 438 439 /* This comes from a parent namespace. Return as a v2 capability */ 440 size = sizeof(struct vfs_cap_data); 441 if (alloc) { 442 *buffer = kmalloc(size, GFP_ATOMIC); 443 if (*buffer) { 444 struct vfs_cap_data *cap = *buffer; 445 __le32 nsmagic, magic; 446 magic = VFS_CAP_REVISION_2; 447 nsmagic = le32_to_cpu(nscap->magic_etc); 448 if (nsmagic & VFS_CAP_FLAGS_EFFECTIVE) 449 magic |= VFS_CAP_FLAGS_EFFECTIVE; 450 memcpy(&cap->data, &nscap->data, sizeof(__le32) * 2 * VFS_CAP_U32); 451 cap->magic_etc = cpu_to_le32(magic); 452 } else { 453 size = -ENOMEM; 454 } 455 } 456 kfree(tmpbuf); 457 return size; 458 } 459 460 static kuid_t rootid_from_xattr(const void *value, size_t size, 461 struct user_namespace *task_ns) 462 { 463 const struct vfs_ns_cap_data *nscap = value; 464 uid_t rootid = 0; 465 466 if (size == XATTR_CAPS_SZ_3) 467 rootid = le32_to_cpu(nscap->rootid); 468 469 return make_kuid(task_ns, rootid); 470 } 471 472 static bool validheader(size_t size, const struct vfs_cap_data *cap) 473 { 474 return is_v2header(size, cap) || is_v3header(size, cap); 475 } 476 477 /* 478 * User requested a write of security.capability. If needed, update the 479 * xattr to change from v2 to v3, or to fixup the v3 rootid. 480 * 481 * If all is ok, we return the new size, on error return < 0. 482 */ 483 int cap_convert_nscap(struct dentry *dentry, void **ivalue, size_t size) 484 { 485 struct vfs_ns_cap_data *nscap; 486 uid_t nsrootid; 487 const struct vfs_cap_data *cap = *ivalue; 488 __u32 magic, nsmagic; 489 struct inode *inode = d_backing_inode(dentry); 490 struct user_namespace *task_ns = current_user_ns(), 491 *fs_ns = inode->i_sb->s_user_ns; 492 kuid_t rootid; 493 size_t newsize; 494 495 if (!*ivalue) 496 return -EINVAL; 497 if (!validheader(size, cap)) 498 return -EINVAL; 499 if (!capable_wrt_inode_uidgid(inode, CAP_SETFCAP)) 500 return -EPERM; 501 if (size == XATTR_CAPS_SZ_2) 502 if (ns_capable(inode->i_sb->s_user_ns, CAP_SETFCAP)) 503 /* user is privileged, just write the v2 */ 504 return size; 505 506 rootid = rootid_from_xattr(*ivalue, size, task_ns); 507 if (!uid_valid(rootid)) 508 return -EINVAL; 509 510 nsrootid = from_kuid(fs_ns, rootid); 511 if (nsrootid == -1) 512 return -EINVAL; 513 514 newsize = sizeof(struct vfs_ns_cap_data); 515 nscap = kmalloc(newsize, GFP_ATOMIC); 516 if (!nscap) 517 return -ENOMEM; 518 nscap->rootid = cpu_to_le32(nsrootid); 519 nsmagic = VFS_CAP_REVISION_3; 520 magic = le32_to_cpu(cap->magic_etc); 521 if (magic & VFS_CAP_FLAGS_EFFECTIVE) 522 nsmagic |= VFS_CAP_FLAGS_EFFECTIVE; 523 nscap->magic_etc = cpu_to_le32(nsmagic); 524 memcpy(&nscap->data, &cap->data, sizeof(__le32) * 2 * VFS_CAP_U32); 525 526 kvfree(*ivalue); 527 *ivalue = nscap; 528 return newsize; 529 } 530 531 /* 532 * Calculate the new process capability sets from the capability sets attached 533 * to a file. 534 */ 535 static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, 536 struct linux_binprm *bprm, 537 bool *effective, 538 bool *has_fcap) 539 { 540 struct cred *new = bprm->cred; 541 unsigned i; 542 int ret = 0; 543 544 if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE) 545 *effective = true; 546 547 if (caps->magic_etc & VFS_CAP_REVISION_MASK) 548 *has_fcap = true; 549 550 CAP_FOR_EACH_U32(i) { 551 __u32 permitted = caps->permitted.cap[i]; 552 __u32 inheritable = caps->inheritable.cap[i]; 553 554 /* 555 * pP' = (X & fP) | (pI & fI) 556 * The addition of pA' is handled later. 557 */ 558 new->cap_permitted.cap[i] = 559 (new->cap_bset.cap[i] & permitted) | 560 (new->cap_inheritable.cap[i] & inheritable); 561 562 if (permitted & ~new->cap_permitted.cap[i]) 563 /* insufficient to execute correctly */ 564 ret = -EPERM; 565 } 566 567 /* 568 * For legacy apps, with no internal support for recognizing they 569 * do not have enough capabilities, we return an error if they are 570 * missing some "forced" (aka file-permitted) capabilities. 571 */ 572 return *effective ? ret : 0; 573 } 574 575 /* 576 * Extract the on-exec-apply capability sets for an executable file. 577 */ 578 int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps) 579 { 580 struct inode *inode = d_backing_inode(dentry); 581 __u32 magic_etc; 582 unsigned tocopy, i; 583 int size; 584 struct vfs_ns_cap_data data, *nscaps = &data; 585 struct vfs_cap_data *caps = (struct vfs_cap_data *) &data; 586 kuid_t rootkuid; 587 struct user_namespace *fs_ns; 588 589 memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data)); 590 591 if (!inode) 592 return -ENODATA; 593 594 fs_ns = inode->i_sb->s_user_ns; 595 size = __vfs_getxattr((struct dentry *)dentry, inode, 596 XATTR_NAME_CAPS, &data, XATTR_CAPS_SZ); 597 if (size == -ENODATA || size == -EOPNOTSUPP) 598 /* no data, that's ok */ 599 return -ENODATA; 600 601 if (size < 0) 602 return size; 603 604 if (size < sizeof(magic_etc)) 605 return -EINVAL; 606 607 cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps->magic_etc); 608 609 rootkuid = make_kuid(fs_ns, 0); 610 switch (magic_etc & VFS_CAP_REVISION_MASK) { 611 case VFS_CAP_REVISION_1: 612 if (size != XATTR_CAPS_SZ_1) 613 return -EINVAL; 614 tocopy = VFS_CAP_U32_1; 615 break; 616 case VFS_CAP_REVISION_2: 617 if (size != XATTR_CAPS_SZ_2) 618 return -EINVAL; 619 tocopy = VFS_CAP_U32_2; 620 break; 621 case VFS_CAP_REVISION_3: 622 if (size != XATTR_CAPS_SZ_3) 623 return -EINVAL; 624 tocopy = VFS_CAP_U32_3; 625 rootkuid = make_kuid(fs_ns, le32_to_cpu(nscaps->rootid)); 626 break; 627 628 default: 629 return -EINVAL; 630 } 631 /* Limit the caps to the mounter of the filesystem 632 * or the more limited uid specified in the xattr. 633 */ 634 if (!rootid_owns_currentns(rootkuid)) 635 return -ENODATA; 636 637 CAP_FOR_EACH_U32(i) { 638 if (i >= tocopy) 639 break; 640 cpu_caps->permitted.cap[i] = le32_to_cpu(caps->data[i].permitted); 641 cpu_caps->inheritable.cap[i] = le32_to_cpu(caps->data[i].inheritable); 642 } 643 644 cpu_caps->permitted.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK; 645 cpu_caps->inheritable.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK; 646 647 return 0; 648 } 649 650 /* 651 * Attempt to get the on-exec apply capability sets for an executable file from 652 * its xattrs and, if present, apply them to the proposed credentials being 653 * constructed by execve(). 654 */ 655 static int get_file_caps(struct linux_binprm *bprm, bool *effective, bool *has_fcap) 656 { 657 int rc = 0; 658 struct cpu_vfs_cap_data vcaps; 659 660 cap_clear(bprm->cred->cap_permitted); 661 662 if (!file_caps_enabled) 663 return 0; 664 665 if (!mnt_may_suid(bprm->file->f_path.mnt)) 666 return 0; 667 668 /* 669 * This check is redundant with mnt_may_suid() but is kept to make 670 * explicit that capability bits are limited to s_user_ns and its 671 * descendants. 672 */ 673 if (!current_in_userns(bprm->file->f_path.mnt->mnt_sb->s_user_ns)) 674 return 0; 675 676 rc = get_vfs_caps_from_disk(bprm->file->f_path.dentry, &vcaps); 677 if (rc < 0) { 678 if (rc == -EINVAL) 679 printk(KERN_NOTICE "Invalid argument reading file caps for %s\n", 680 bprm->filename); 681 else if (rc == -ENODATA) 682 rc = 0; 683 goto out; 684 } 685 686 rc = bprm_caps_from_vfs_caps(&vcaps, bprm, effective, has_fcap); 687 if (rc == -EINVAL) 688 printk(KERN_NOTICE "%s: cap_from_disk returned %d for %s\n", 689 __func__, rc, bprm->filename); 690 691 out: 692 if (rc) 693 cap_clear(bprm->cred->cap_permitted); 694 695 return rc; 696 } 697 698 static inline bool root_privileged(void) { return !issecure(SECURE_NOROOT); } 699 700 static inline bool __is_real(kuid_t uid, struct cred *cred) 701 { return uid_eq(cred->uid, uid); } 702 703 static inline bool __is_eff(kuid_t uid, struct cred *cred) 704 { return uid_eq(cred->euid, uid); } 705 706 static inline bool __is_suid(kuid_t uid, struct cred *cred) 707 { return !__is_real(uid, cred) && __is_eff(uid, cred); } 708 709 /* 710 * handle_privileged_root - Handle case of privileged root 711 * @bprm: The execution parameters, including the proposed creds 712 * @has_fcap: Are any file capabilities set? 713 * @effective: Do we have effective root privilege? 714 * @root_uid: This namespace' root UID WRT initial USER namespace 715 * 716 * Handle the case where root is privileged and hasn't been neutered by 717 * SECURE_NOROOT. If file capabilities are set, they won't be combined with 718 * set UID root and nothing is changed. If we are root, cap_permitted is 719 * updated. If we have become set UID root, the effective bit is set. 720 */ 721 static void handle_privileged_root(struct linux_binprm *bprm, bool has_fcap, 722 bool *effective, kuid_t root_uid) 723 { 724 const struct cred *old = current_cred(); 725 struct cred *new = bprm->cred; 726 727 if (!root_privileged()) 728 return; 729 /* 730 * If the legacy file capability is set, then don't set privs 731 * for a setuid root binary run by a non-root user. Do set it 732 * for a root user just to cause least surprise to an admin. 733 */ 734 if (has_fcap && __is_suid(root_uid, new)) { 735 warn_setuid_and_fcaps_mixed(bprm->filename); 736 return; 737 } 738 /* 739 * To support inheritance of root-permissions and suid-root 740 * executables under compatibility mode, we override the 741 * capability sets for the file. 742 */ 743 if (__is_eff(root_uid, new) || __is_real(root_uid, new)) { 744 /* pP' = (cap_bset & ~0) | (pI & ~0) */ 745 new->cap_permitted = cap_combine(old->cap_bset, 746 old->cap_inheritable); 747 } 748 /* 749 * If only the real uid is 0, we do not set the effective bit. 750 */ 751 if (__is_eff(root_uid, new)) 752 *effective = true; 753 } 754 755 #define __cap_gained(field, target, source) \ 756 !cap_issubset(target->cap_##field, source->cap_##field) 757 #define __cap_grew(target, source, cred) \ 758 !cap_issubset(cred->cap_##target, cred->cap_##source) 759 #define __cap_full(field, cred) \ 760 cap_issubset(CAP_FULL_SET, cred->cap_##field) 761 762 static inline bool __is_setuid(struct cred *new, const struct cred *old) 763 { return !uid_eq(new->euid, old->uid); } 764 765 static inline bool __is_setgid(struct cred *new, const struct cred *old) 766 { return !gid_eq(new->egid, old->gid); } 767 768 /* 769 * 1) Audit candidate if current->cap_effective is set 770 * 771 * We do not bother to audit if 3 things are true: 772 * 1) cap_effective has all caps 773 * 2) we became root *OR* are were already root 774 * 3) root is supposed to have all caps (SECURE_NOROOT) 775 * Since this is just a normal root execing a process. 776 * 777 * Number 1 above might fail if you don't have a full bset, but I think 778 * that is interesting information to audit. 779 * 780 * A number of other conditions require logging: 781 * 2) something prevented setuid root getting all caps 782 * 3) non-setuid root gets fcaps 783 * 4) non-setuid root gets ambient 784 */ 785 static inline bool nonroot_raised_pE(struct cred *new, const struct cred *old, 786 kuid_t root, bool has_fcap) 787 { 788 bool ret = false; 789 790 if ((__cap_grew(effective, ambient, new) && 791 !(__cap_full(effective, new) && 792 (__is_eff(root, new) || __is_real(root, new)) && 793 root_privileged())) || 794 (root_privileged() && 795 __is_suid(root, new) && 796 !__cap_full(effective, new)) || 797 (!__is_setuid(new, old) && 798 ((has_fcap && 799 __cap_gained(permitted, new, old)) || 800 __cap_gained(ambient, new, old)))) 801 802 ret = true; 803 804 return ret; 805 } 806 807 /** 808 * cap_bprm_set_creds - Set up the proposed credentials for execve(). 809 * @bprm: The execution parameters, including the proposed creds 810 * 811 * Set up the proposed credentials for a new execution context being 812 * constructed by execve(). The proposed creds in @bprm->cred is altered, 813 * which won't take effect immediately. Returns 0 if successful, -ve on error. 814 */ 815 int cap_bprm_set_creds(struct linux_binprm *bprm) 816 { 817 const struct cred *old = current_cred(); 818 struct cred *new = bprm->cred; 819 bool effective = false, has_fcap = false, is_setid; 820 int ret; 821 kuid_t root_uid; 822 823 if (WARN_ON(!cap_ambient_invariant_ok(old))) 824 return -EPERM; 825 826 ret = get_file_caps(bprm, &effective, &has_fcap); 827 if (ret < 0) 828 return ret; 829 830 root_uid = make_kuid(new->user_ns, 0); 831 832 handle_privileged_root(bprm, has_fcap, &effective, root_uid); 833 834 /* if we have fs caps, clear dangerous personality flags */ 835 if (__cap_gained(permitted, new, old)) 836 bprm->per_clear |= PER_CLEAR_ON_SETID; 837 838 /* Don't let someone trace a set[ug]id/setpcap binary with the revised 839 * credentials unless they have the appropriate permit. 840 * 841 * In addition, if NO_NEW_PRIVS, then ensure we get no new privs. 842 */ 843 is_setid = __is_setuid(new, old) || __is_setgid(new, old); 844 845 if ((is_setid || __cap_gained(permitted, new, old)) && 846 ((bprm->unsafe & ~LSM_UNSAFE_PTRACE) || 847 !ptracer_capable(current, new->user_ns))) { 848 /* downgrade; they get no more than they had, and maybe less */ 849 if (!ns_capable(new->user_ns, CAP_SETUID) || 850 (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)) { 851 new->euid = new->uid; 852 new->egid = new->gid; 853 } 854 new->cap_permitted = cap_intersect(new->cap_permitted, 855 old->cap_permitted); 856 } 857 858 new->suid = new->fsuid = new->euid; 859 new->sgid = new->fsgid = new->egid; 860 861 /* File caps or setid cancels ambient. */ 862 if (has_fcap || is_setid) 863 cap_clear(new->cap_ambient); 864 865 /* 866 * Now that we've computed pA', update pP' to give: 867 * pP' = (X & fP) | (pI & fI) | pA' 868 */ 869 new->cap_permitted = cap_combine(new->cap_permitted, new->cap_ambient); 870 871 /* 872 * Set pE' = (fE ? pP' : pA'). Because pA' is zero if fE is set, 873 * this is the same as pE' = (fE ? pP' : 0) | pA'. 874 */ 875 if (effective) 876 new->cap_effective = new->cap_permitted; 877 else 878 new->cap_effective = new->cap_ambient; 879 880 if (WARN_ON(!cap_ambient_invariant_ok(new))) 881 return -EPERM; 882 883 if (nonroot_raised_pE(new, old, root_uid, has_fcap)) { 884 ret = audit_log_bprm_fcaps(bprm, new, old); 885 if (ret < 0) 886 return ret; 887 } 888 889 new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); 890 891 if (WARN_ON(!cap_ambient_invariant_ok(new))) 892 return -EPERM; 893 894 /* Check for privilege-elevated exec. */ 895 bprm->cap_elevated = 0; 896 if (is_setid || 897 (!__is_real(root_uid, new) && 898 (effective || 899 __cap_grew(permitted, ambient, new)))) 900 bprm->cap_elevated = 1; 901 902 return 0; 903 } 904 905 /** 906 * cap_inode_setxattr - Determine whether an xattr may be altered 907 * @dentry: The inode/dentry being altered 908 * @name: The name of the xattr to be changed 909 * @value: The value that the xattr will be changed to 910 * @size: The size of value 911 * @flags: The replacement flag 912 * 913 * Determine whether an xattr may be altered or set on an inode, returning 0 if 914 * permission is granted, -ve if denied. 915 * 916 * This is used to make sure security xattrs don't get updated or set by those 917 * who aren't privileged to do so. 918 */ 919 int cap_inode_setxattr(struct dentry *dentry, const char *name, 920 const void *value, size_t size, int flags) 921 { 922 struct user_namespace *user_ns = dentry->d_sb->s_user_ns; 923 924 /* Ignore non-security xattrs */ 925 if (strncmp(name, XATTR_SECURITY_PREFIX, 926 sizeof(XATTR_SECURITY_PREFIX) - 1) != 0) 927 return 0; 928 929 /* 930 * For XATTR_NAME_CAPS the check will be done in 931 * cap_convert_nscap(), called by setxattr() 932 */ 933 if (strcmp(name, XATTR_NAME_CAPS) == 0) 934 return 0; 935 936 if (!ns_capable(user_ns, CAP_SYS_ADMIN)) 937 return -EPERM; 938 return 0; 939 } 940 941 /** 942 * cap_inode_removexattr - Determine whether an xattr may be removed 943 * @dentry: The inode/dentry being altered 944 * @name: The name of the xattr to be changed 945 * 946 * Determine whether an xattr may be removed from an inode, returning 0 if 947 * permission is granted, -ve if denied. 948 * 949 * This is used to make sure security xattrs don't get removed by those who 950 * aren't privileged to remove them. 951 */ 952 int cap_inode_removexattr(struct dentry *dentry, const char *name) 953 { 954 struct user_namespace *user_ns = dentry->d_sb->s_user_ns; 955 956 /* Ignore non-security xattrs */ 957 if (strncmp(name, XATTR_SECURITY_PREFIX, 958 sizeof(XATTR_SECURITY_PREFIX) - 1) != 0) 959 return 0; 960 961 if (strcmp(name, XATTR_NAME_CAPS) == 0) { 962 /* security.capability gets namespaced */ 963 struct inode *inode = d_backing_inode(dentry); 964 if (!inode) 965 return -EINVAL; 966 if (!capable_wrt_inode_uidgid(inode, CAP_SETFCAP)) 967 return -EPERM; 968 return 0; 969 } 970 971 if (!ns_capable(user_ns, CAP_SYS_ADMIN)) 972 return -EPERM; 973 return 0; 974 } 975 976 /* 977 * cap_emulate_setxuid() fixes the effective / permitted capabilities of 978 * a process after a call to setuid, setreuid, or setresuid. 979 * 980 * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of 981 * {r,e,s}uid != 0, the permitted and effective capabilities are 982 * cleared. 983 * 984 * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective 985 * capabilities of the process are cleared. 986 * 987 * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective 988 * capabilities are set to the permitted capabilities. 989 * 990 * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should 991 * never happen. 992 * 993 * -astor 994 * 995 * cevans - New behaviour, Oct '99 996 * A process may, via prctl(), elect to keep its capabilities when it 997 * calls setuid() and switches away from uid==0. Both permitted and 998 * effective sets will be retained. 999 * Without this change, it was impossible for a daemon to drop only some 1000 * of its privilege. The call to setuid(!=0) would drop all privileges! 1001 * Keeping uid 0 is not an option because uid 0 owns too many vital 1002 * files.. 1003 * Thanks to Olaf Kirch and Peter Benie for spotting this. 1004 */ 1005 static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old) 1006 { 1007 kuid_t root_uid = make_kuid(old->user_ns, 0); 1008 1009 if ((uid_eq(old->uid, root_uid) || 1010 uid_eq(old->euid, root_uid) || 1011 uid_eq(old->suid, root_uid)) && 1012 (!uid_eq(new->uid, root_uid) && 1013 !uid_eq(new->euid, root_uid) && 1014 !uid_eq(new->suid, root_uid))) { 1015 if (!issecure(SECURE_KEEP_CAPS)) { 1016 cap_clear(new->cap_permitted); 1017 cap_clear(new->cap_effective); 1018 } 1019 1020 /* 1021 * Pre-ambient programs expect setresuid to nonroot followed 1022 * by exec to drop capabilities. We should make sure that 1023 * this remains the case. 1024 */ 1025 cap_clear(new->cap_ambient); 1026 } 1027 if (uid_eq(old->euid, root_uid) && !uid_eq(new->euid, root_uid)) 1028 cap_clear(new->cap_effective); 1029 if (!uid_eq(old->euid, root_uid) && uid_eq(new->euid, root_uid)) 1030 new->cap_effective = new->cap_permitted; 1031 } 1032 1033 /** 1034 * cap_task_fix_setuid - Fix up the results of setuid() call 1035 * @new: The proposed credentials 1036 * @old: The current task's current credentials 1037 * @flags: Indications of what has changed 1038 * 1039 * Fix up the results of setuid() call before the credential changes are 1040 * actually applied, returning 0 to grant the changes, -ve to deny them. 1041 */ 1042 int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags) 1043 { 1044 switch (flags) { 1045 case LSM_SETID_RE: 1046 case LSM_SETID_ID: 1047 case LSM_SETID_RES: 1048 /* juggle the capabilities to follow [RES]UID changes unless 1049 * otherwise suppressed */ 1050 if (!issecure(SECURE_NO_SETUID_FIXUP)) 1051 cap_emulate_setxuid(new, old); 1052 break; 1053 1054 case LSM_SETID_FS: 1055 /* juggle the capabilties to follow FSUID changes, unless 1056 * otherwise suppressed 1057 * 1058 * FIXME - is fsuser used for all CAP_FS_MASK capabilities? 1059 * if not, we might be a bit too harsh here. 1060 */ 1061 if (!issecure(SECURE_NO_SETUID_FIXUP)) { 1062 kuid_t root_uid = make_kuid(old->user_ns, 0); 1063 if (uid_eq(old->fsuid, root_uid) && !uid_eq(new->fsuid, root_uid)) 1064 new->cap_effective = 1065 cap_drop_fs_set(new->cap_effective); 1066 1067 if (!uid_eq(old->fsuid, root_uid) && uid_eq(new->fsuid, root_uid)) 1068 new->cap_effective = 1069 cap_raise_fs_set(new->cap_effective, 1070 new->cap_permitted); 1071 } 1072 break; 1073 1074 default: 1075 return -EINVAL; 1076 } 1077 1078 return 0; 1079 } 1080 1081 /* 1082 * Rationale: code calling task_setscheduler, task_setioprio, and 1083 * task_setnice, assumes that 1084 * . if capable(cap_sys_nice), then those actions should be allowed 1085 * . if not capable(cap_sys_nice), but acting on your own processes, 1086 * then those actions should be allowed 1087 * This is insufficient now since you can call code without suid, but 1088 * yet with increased caps. 1089 * So we check for increased caps on the target process. 1090 */ 1091 static int cap_safe_nice(struct task_struct *p) 1092 { 1093 int is_subset, ret = 0; 1094 1095 rcu_read_lock(); 1096 is_subset = cap_issubset(__task_cred(p)->cap_permitted, 1097 current_cred()->cap_permitted); 1098 if (!is_subset && !ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) 1099 ret = -EPERM; 1100 rcu_read_unlock(); 1101 1102 return ret; 1103 } 1104 1105 /** 1106 * cap_task_setscheduler - Detemine if scheduler policy change is permitted 1107 * @p: The task to affect 1108 * 1109 * Detemine if the requested scheduler policy change is permitted for the 1110 * specified task, returning 0 if permission is granted, -ve if denied. 1111 */ 1112 int cap_task_setscheduler(struct task_struct *p) 1113 { 1114 return cap_safe_nice(p); 1115 } 1116 1117 /** 1118 * cap_task_ioprio - Detemine if I/O priority change is permitted 1119 * @p: The task to affect 1120 * @ioprio: The I/O priority to set 1121 * 1122 * Detemine if the requested I/O priority change is permitted for the specified 1123 * task, returning 0 if permission is granted, -ve if denied. 1124 */ 1125 int cap_task_setioprio(struct task_struct *p, int ioprio) 1126 { 1127 return cap_safe_nice(p); 1128 } 1129 1130 /** 1131 * cap_task_ioprio - Detemine if task priority change is permitted 1132 * @p: The task to affect 1133 * @nice: The nice value to set 1134 * 1135 * Detemine if the requested task priority change is permitted for the 1136 * specified task, returning 0 if permission is granted, -ve if denied. 1137 */ 1138 int cap_task_setnice(struct task_struct *p, int nice) 1139 { 1140 return cap_safe_nice(p); 1141 } 1142 1143 /* 1144 * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from 1145 * the current task's bounding set. Returns 0 on success, -ve on error. 1146 */ 1147 static int cap_prctl_drop(unsigned long cap) 1148 { 1149 struct cred *new; 1150 1151 if (!ns_capable(current_user_ns(), CAP_SETPCAP)) 1152 return -EPERM; 1153 if (!cap_valid(cap)) 1154 return -EINVAL; 1155 1156 new = prepare_creds(); 1157 if (!new) 1158 return -ENOMEM; 1159 cap_lower(new->cap_bset, cap); 1160 return commit_creds(new); 1161 } 1162 1163 /** 1164 * cap_task_prctl - Implement process control functions for this security module 1165 * @option: The process control function requested 1166 * @arg2, @arg3, @arg4, @arg5: The argument data for this function 1167 * 1168 * Allow process control functions (sys_prctl()) to alter capabilities; may 1169 * also deny access to other functions not otherwise implemented here. 1170 * 1171 * Returns 0 or +ve on success, -ENOSYS if this function is not implemented 1172 * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM 1173 * modules will consider performing the function. 1174 */ 1175 int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, 1176 unsigned long arg4, unsigned long arg5) 1177 { 1178 const struct cred *old = current_cred(); 1179 struct cred *new; 1180 1181 switch (option) { 1182 case PR_CAPBSET_READ: 1183 if (!cap_valid(arg2)) 1184 return -EINVAL; 1185 return !!cap_raised(old->cap_bset, arg2); 1186 1187 case PR_CAPBSET_DROP: 1188 return cap_prctl_drop(arg2); 1189 1190 /* 1191 * The next four prctl's remain to assist with transitioning a 1192 * system from legacy UID=0 based privilege (when filesystem 1193 * capabilities are not in use) to a system using filesystem 1194 * capabilities only - as the POSIX.1e draft intended. 1195 * 1196 * Note: 1197 * 1198 * PR_SET_SECUREBITS = 1199 * issecure_mask(SECURE_KEEP_CAPS_LOCKED) 1200 * | issecure_mask(SECURE_NOROOT) 1201 * | issecure_mask(SECURE_NOROOT_LOCKED) 1202 * | issecure_mask(SECURE_NO_SETUID_FIXUP) 1203 * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED) 1204 * 1205 * will ensure that the current process and all of its 1206 * children will be locked into a pure 1207 * capability-based-privilege environment. 1208 */ 1209 case PR_SET_SECUREBITS: 1210 if ((((old->securebits & SECURE_ALL_LOCKS) >> 1) 1211 & (old->securebits ^ arg2)) /*[1]*/ 1212 || ((old->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/ 1213 || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ 1214 || (cap_capable(current_cred(), 1215 current_cred()->user_ns, CAP_SETPCAP, 1216 SECURITY_CAP_AUDIT) != 0) /*[4]*/ 1217 /* 1218 * [1] no changing of bits that are locked 1219 * [2] no unlocking of locks 1220 * [3] no setting of unsupported bits 1221 * [4] doing anything requires privilege (go read about 1222 * the "sendmail capabilities bug") 1223 */ 1224 ) 1225 /* cannot change a locked bit */ 1226 return -EPERM; 1227 1228 new = prepare_creds(); 1229 if (!new) 1230 return -ENOMEM; 1231 new->securebits = arg2; 1232 return commit_creds(new); 1233 1234 case PR_GET_SECUREBITS: 1235 return old->securebits; 1236 1237 case PR_GET_KEEPCAPS: 1238 return !!issecure(SECURE_KEEP_CAPS); 1239 1240 case PR_SET_KEEPCAPS: 1241 if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */ 1242 return -EINVAL; 1243 if (issecure(SECURE_KEEP_CAPS_LOCKED)) 1244 return -EPERM; 1245 1246 new = prepare_creds(); 1247 if (!new) 1248 return -ENOMEM; 1249 if (arg2) 1250 new->securebits |= issecure_mask(SECURE_KEEP_CAPS); 1251 else 1252 new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); 1253 return commit_creds(new); 1254 1255 case PR_CAP_AMBIENT: 1256 if (arg2 == PR_CAP_AMBIENT_CLEAR_ALL) { 1257 if (arg3 | arg4 | arg5) 1258 return -EINVAL; 1259 1260 new = prepare_creds(); 1261 if (!new) 1262 return -ENOMEM; 1263 cap_clear(new->cap_ambient); 1264 return commit_creds(new); 1265 } 1266 1267 if (((!cap_valid(arg3)) | arg4 | arg5)) 1268 return -EINVAL; 1269 1270 if (arg2 == PR_CAP_AMBIENT_IS_SET) { 1271 return !!cap_raised(current_cred()->cap_ambient, arg3); 1272 } else if (arg2 != PR_CAP_AMBIENT_RAISE && 1273 arg2 != PR_CAP_AMBIENT_LOWER) { 1274 return -EINVAL; 1275 } else { 1276 if (arg2 == PR_CAP_AMBIENT_RAISE && 1277 (!cap_raised(current_cred()->cap_permitted, arg3) || 1278 !cap_raised(current_cred()->cap_inheritable, 1279 arg3) || 1280 issecure(SECURE_NO_CAP_AMBIENT_RAISE))) 1281 return -EPERM; 1282 1283 new = prepare_creds(); 1284 if (!new) 1285 return -ENOMEM; 1286 if (arg2 == PR_CAP_AMBIENT_RAISE) 1287 cap_raise(new->cap_ambient, arg3); 1288 else 1289 cap_lower(new->cap_ambient, arg3); 1290 return commit_creds(new); 1291 } 1292 1293 default: 1294 /* No functionality available - continue with default */ 1295 return -ENOSYS; 1296 } 1297 } 1298 1299 /** 1300 * cap_vm_enough_memory - Determine whether a new virtual mapping is permitted 1301 * @mm: The VM space in which the new mapping is to be made 1302 * @pages: The size of the mapping 1303 * 1304 * Determine whether the allocation of a new virtual mapping by the current 1305 * task is permitted, returning 1 if permission is granted, 0 if not. 1306 */ 1307 int cap_vm_enough_memory(struct mm_struct *mm, long pages) 1308 { 1309 int cap_sys_admin = 0; 1310 1311 if (cap_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN, 1312 SECURITY_CAP_NOAUDIT) == 0) 1313 cap_sys_admin = 1; 1314 return cap_sys_admin; 1315 } 1316 1317 /* 1318 * cap_mmap_addr - check if able to map given addr 1319 * @addr: address attempting to be mapped 1320 * 1321 * If the process is attempting to map memory below dac_mmap_min_addr they need 1322 * CAP_SYS_RAWIO. The other parameters to this function are unused by the 1323 * capability security module. Returns 0 if this mapping should be allowed 1324 * -EPERM if not. 1325 */ 1326 int cap_mmap_addr(unsigned long addr) 1327 { 1328 int ret = 0; 1329 1330 if (addr < dac_mmap_min_addr) { 1331 ret = cap_capable(current_cred(), &init_user_ns, CAP_SYS_RAWIO, 1332 SECURITY_CAP_AUDIT); 1333 /* set PF_SUPERPRIV if it turns out we allow the low mmap */ 1334 if (ret == 0) 1335 current->flags |= PF_SUPERPRIV; 1336 } 1337 return ret; 1338 } 1339 1340 int cap_mmap_file(struct file *file, unsigned long reqprot, 1341 unsigned long prot, unsigned long flags) 1342 { 1343 return 0; 1344 } 1345 1346 #ifdef CONFIG_SECURITY 1347 1348 struct security_hook_list capability_hooks[] __lsm_ro_after_init = { 1349 LSM_HOOK_INIT(capable, cap_capable), 1350 LSM_HOOK_INIT(settime, cap_settime), 1351 LSM_HOOK_INIT(ptrace_access_check, cap_ptrace_access_check), 1352 LSM_HOOK_INIT(ptrace_traceme, cap_ptrace_traceme), 1353 LSM_HOOK_INIT(capget, cap_capget), 1354 LSM_HOOK_INIT(capset, cap_capset), 1355 LSM_HOOK_INIT(bprm_set_creds, cap_bprm_set_creds), 1356 LSM_HOOK_INIT(inode_need_killpriv, cap_inode_need_killpriv), 1357 LSM_HOOK_INIT(inode_killpriv, cap_inode_killpriv), 1358 LSM_HOOK_INIT(inode_getsecurity, cap_inode_getsecurity), 1359 LSM_HOOK_INIT(mmap_addr, cap_mmap_addr), 1360 LSM_HOOK_INIT(mmap_file, cap_mmap_file), 1361 LSM_HOOK_INIT(task_fix_setuid, cap_task_fix_setuid), 1362 LSM_HOOK_INIT(task_prctl, cap_task_prctl), 1363 LSM_HOOK_INIT(task_setscheduler, cap_task_setscheduler), 1364 LSM_HOOK_INIT(task_setioprio, cap_task_setioprio), 1365 LSM_HOOK_INIT(task_setnice, cap_task_setnice), 1366 LSM_HOOK_INIT(vm_enough_memory, cap_vm_enough_memory), 1367 }; 1368 1369 void __init capability_add_hooks(void) 1370 { 1371 security_add_hooks(capability_hooks, ARRAY_SIZE(capability_hooks), 1372 "capability"); 1373 } 1374 1375 #endif /* CONFIG_SECURITY */ 1376