1// SPDX-License-Identifier: GPL-2.0-or-later 2/* Common capabilities, needed by capability.o. 3 */ 4 5#include <linux/capability.h> 6#include <linux/audit.h> 7#include <linux/init.h> 8#include <linux/kernel.h> 9#include <linux/lsm_hooks.h> 10#include <linux/file.h> 11#include <linux/mm.h> 12#include <linux/mman.h> 13#include <linux/pagemap.h> 14#include <linux/swap.h> 15#include <linux/skbuff.h> 16#include <linux/netlink.h> 17#include <linux/ptrace.h> 18#include <linux/xattr.h> 19#include <linux/hugetlb.h> 20#include <linux/mount.h> 21#include <linux/sched.h> 22#include <linux/prctl.h> 23#include <linux/securebits.h> 24#include <linux/user_namespace.h> 25#include <linux/binfmts.h> 26#include <linux/personality.h> 27 28/* 29 * If a non-root user executes a setuid-root binary in 30 * !secure(SECURE_NOROOT) mode, then we raise capabilities. 31 * However if fE is also set, then the intent is for only 32 * the file capabilities to be applied, and the setuid-root 33 * bit is left on either to change the uid (plausible) or 34 * to get full privilege on a kernel without file capabilities 35 * support. So in that case we do not raise capabilities. 36 * 37 * Warn if that happens, once per boot. 38 */ 39static void warn_setuid_and_fcaps_mixed(const char *fname) 40{ 41 static int warned; 42 if (!warned) { 43 printk(KERN_INFO "warning: `%s' has both setuid-root and" 44 " effective capabilities. Therefore not raising all" 45 " capabilities.\n", fname); 46 warned = 1; 47 } 48} 49 50/** 51 * cap_capable - Determine whether a task has a particular effective capability 52 * @cred: The credentials to use 53 * @ns: The user namespace in which we need the capability 54 * @cap: The capability to check for 55 * @opts: Bitmask of options defined in include/linux/security.h 56 * 57 * Determine whether the nominated task has the specified capability amongst 58 * its effective set, returning 0 if it does, -ve if it does not. 59 * 60 * NOTE WELL: cap_has_capability() cannot be used like the kernel's capable() 61 * and has_capability() functions. That is, it has the reverse semantics: 62 * cap_has_capability() returns 0 when a task has a capability, but the 63 * kernel's capable() and has_capability() returns 1 for this case. 64 */ 65int cap_capable(const struct cred *cred, struct user_namespace *targ_ns, 66 int cap, unsigned int opts) 67{ 68 struct user_namespace *ns = targ_ns; 69 70 /* See if cred has the capability in the target user namespace 71 * by examining the target user namespace and all of the target 72 * user namespace's parents. 73 */ 74 for (;;) { 75 /* Do we have the necessary capabilities? */ 76 if (ns == cred->user_ns) 77 return cap_raised(cred->cap_effective, cap) ? 0 : -EPERM; 78 79 /* 80 * If we're already at a lower level than we're looking for, 81 * we're done searching. 82 */ 83 if (ns->level <= cred->user_ns->level) 84 return -EPERM; 85 86 /* 87 * The owner of the user namespace in the parent of the 88 * user namespace has all caps. 89 */ 90 if ((ns->parent == cred->user_ns) && uid_eq(ns->owner, cred->euid)) 91 return 0; 92 93 /* 94 * If you have a capability in a parent user ns, then you have 95 * it over all children user namespaces as well. 96 */ 97 ns = ns->parent; 98 } 99 100 /* We never get here */ 101} 102 103/** 104 * cap_settime - Determine whether the current process may set the system clock 105 * @ts: The time to set 106 * @tz: The timezone to set 107 * 108 * Determine whether the current process may set the system clock and timezone 109 * information, returning 0 if permission granted, -ve if denied. 110 */ 111int cap_settime(const struct timespec64 *ts, const struct timezone *tz) 112{ 113 if (!capable(CAP_SYS_TIME)) 114 return -EPERM; 115 return 0; 116} 117 118/** 119 * cap_ptrace_access_check - Determine whether the current process may access 120 * another 121 * @child: The process to be accessed 122 * @mode: The mode of attachment. 123 * 124 * If we are in the same or an ancestor user_ns and have all the target 125 * task's capabilities, then ptrace access is allowed. 126 * If we have the ptrace capability to the target user_ns, then ptrace 127 * access is allowed. 128 * Else denied. 129 * 130 * Determine whether a process may access another, returning 0 if permission 131 * granted, -ve if denied. 132 */ 133int cap_ptrace_access_check(struct task_struct *child, unsigned int mode) 134{ 135 int ret = 0; 136 const struct cred *cred, *child_cred; 137 const kernel_cap_t *caller_caps; 138 139 rcu_read_lock(); 140 cred = current_cred(); 141 child_cred = __task_cred(child); 142 if (mode & PTRACE_MODE_FSCREDS) 143 caller_caps = &cred->cap_effective; 144 else 145 caller_caps = &cred->cap_permitted; 146 if (cred->user_ns == child_cred->user_ns && 147 cap_issubset(child_cred->cap_permitted, *caller_caps)) 148 goto out; 149 if (ns_capable(child_cred->user_ns, CAP_SYS_PTRACE)) 150 goto out; 151 ret = -EPERM; 152out: 153 rcu_read_unlock(); 154 return ret; 155} 156 157/** 158 * cap_ptrace_traceme - Determine whether another process may trace the current 159 * @parent: The task proposed to be the tracer 160 * 161 * If parent is in the same or an ancestor user_ns and has all current's 162 * capabilities, then ptrace access is allowed. 163 * If parent has the ptrace capability to current's user_ns, then ptrace 164 * access is allowed. 165 * Else denied. 166 * 167 * Determine whether the nominated task is permitted to trace the current 168 * process, returning 0 if permission is granted, -ve if denied. 169 */ 170int cap_ptrace_traceme(struct task_struct *parent) 171{ 172 int ret = 0; 173 const struct cred *cred, *child_cred; 174 175 rcu_read_lock(); 176 cred = __task_cred(parent); 177 child_cred = current_cred(); 178 if (cred->user_ns == child_cred->user_ns && 179 cap_issubset(child_cred->cap_permitted, cred->cap_permitted)) 180 goto out; 181 if (has_ns_capability(parent, child_cred->user_ns, CAP_SYS_PTRACE)) 182 goto out; 183 ret = -EPERM; 184out: 185 rcu_read_unlock(); 186 return ret; 187} 188 189/** 190 * cap_capget - Retrieve a task's capability sets 191 * @target: The task from which to retrieve the capability sets 192 * @effective: The place to record the effective set 193 * @inheritable: The place to record the inheritable set 194 * @permitted: The place to record the permitted set 195 * 196 * This function retrieves the capabilities of the nominated task and returns 197 * them to the caller. 198 */ 199int cap_capget(struct task_struct *target, kernel_cap_t *effective, 200 kernel_cap_t *inheritable, kernel_cap_t *permitted) 201{ 202 const struct cred *cred; 203 204 /* Derived from kernel/capability.c:sys_capget. */ 205 rcu_read_lock(); 206 cred = __task_cred(target); 207 *effective = cred->cap_effective; 208 *inheritable = cred->cap_inheritable; 209 *permitted = cred->cap_permitted; 210 rcu_read_unlock(); 211 return 0; 212} 213 214/* 215 * Determine whether the inheritable capabilities are limited to the old 216 * permitted set. Returns 1 if they are limited, 0 if they are not. 217 */ 218static inline int cap_inh_is_capped(void) 219{ 220 /* they are so limited unless the current task has the CAP_SETPCAP 221 * capability 222 */ 223 if (cap_capable(current_cred(), current_cred()->user_ns, 224 CAP_SETPCAP, CAP_OPT_NONE) == 0) 225 return 0; 226 return 1; 227} 228 229/** 230 * cap_capset - Validate and apply proposed changes to current's capabilities 231 * @new: The proposed new credentials; alterations should be made here 232 * @old: The current task's current credentials 233 * @effective: A pointer to the proposed new effective capabilities set 234 * @inheritable: A pointer to the proposed new inheritable capabilities set 235 * @permitted: A pointer to the proposed new permitted capabilities set 236 * 237 * This function validates and applies a proposed mass change to the current 238 * process's capability sets. The changes are made to the proposed new 239 * credentials, and assuming no error, will be committed by the caller of LSM. 240 */ 241int cap_capset(struct cred *new, 242 const struct cred *old, 243 const kernel_cap_t *effective, 244 const kernel_cap_t *inheritable, 245 const kernel_cap_t *permitted) 246{ 247 if (cap_inh_is_capped() && 248 !cap_issubset(*inheritable, 249 cap_combine(old->cap_inheritable, 250 old->cap_permitted))) 251 /* incapable of using this inheritable set */ 252 return -EPERM; 253 254 if (!cap_issubset(*inheritable, 255 cap_combine(old->cap_inheritable, 256 old->cap_bset))) 257 /* no new pI capabilities outside bounding set */ 258 return -EPERM; 259 260 /* verify restrictions on target's new Permitted set */ 261 if (!cap_issubset(*permitted, old->cap_permitted)) 262 return -EPERM; 263 264 /* verify the _new_Effective_ is a subset of the _new_Permitted_ */ 265 if (!cap_issubset(*effective, *permitted)) 266 return -EPERM; 267 268 new->cap_effective = *effective; 269 new->cap_inheritable = *inheritable; 270 new->cap_permitted = *permitted; 271 272 /* 273 * Mask off ambient bits that are no longer both permitted and 274 * inheritable. 275 */ 276 new->cap_ambient = cap_intersect(new->cap_ambient, 277 cap_intersect(*permitted, 278 *inheritable)); 279 if (WARN_ON(!cap_ambient_invariant_ok(new))) 280 return -EINVAL; 281 return 0; 282} 283 284/** 285 * cap_inode_need_killpriv - Determine if inode change affects privileges 286 * @dentry: The inode/dentry in being changed with change marked ATTR_KILL_PRIV 287 * 288 * Determine if an inode having a change applied that's marked ATTR_KILL_PRIV 289 * affects the security markings on that inode, and if it is, should 290 * inode_killpriv() be invoked or the change rejected. 291 * 292 * Returns 1 if security.capability has a value, meaning inode_killpriv() 293 * is required, 0 otherwise, meaning inode_killpriv() is not required. 294 */ 295int cap_inode_need_killpriv(struct dentry *dentry) 296{ 297 struct inode *inode = d_backing_inode(dentry); 298 int error; 299 300 error = __vfs_getxattr(dentry, inode, XATTR_NAME_CAPS, NULL, 0); 301 return error > 0; 302} 303 304/** 305 * cap_inode_killpriv - Erase the security markings on an inode 306 * @dentry: The inode/dentry to alter 307 * 308 * Erase the privilege-enhancing security markings on an inode. 309 * 310 * Returns 0 if successful, -ve on error. 311 */ 312int cap_inode_killpriv(struct dentry *dentry) 313{ 314 int error; 315 316 error = __vfs_removexattr(dentry, XATTR_NAME_CAPS); 317 if (error == -EOPNOTSUPP) 318 error = 0; 319 return error; 320} 321 322static bool rootid_owns_currentns(kuid_t kroot) 323{ 324 struct user_namespace *ns; 325 326 if (!uid_valid(kroot)) 327 return false; 328 329 for (ns = current_user_ns(); ; ns = ns->parent) { 330 if (from_kuid(ns, kroot) == 0) 331 return true; 332 if (ns == &init_user_ns) 333 break; 334 } 335 336 return false; 337} 338 339static __u32 sansflags(__u32 m) 340{ 341 return m & ~VFS_CAP_FLAGS_EFFECTIVE; 342} 343 344static bool is_v2header(size_t size, const struct vfs_cap_data *cap) 345{ 346 if (size != XATTR_CAPS_SZ_2) 347 return false; 348 return sansflags(le32_to_cpu(cap->magic_etc)) == VFS_CAP_REVISION_2; 349} 350 351static bool is_v3header(size_t size, const struct vfs_cap_data *cap) 352{ 353 if (size != XATTR_CAPS_SZ_3) 354 return false; 355 return sansflags(le32_to_cpu(cap->magic_etc)) == VFS_CAP_REVISION_3; 356} 357 358/* 359 * getsecurity: We are called for security.* before any attempt to read the 360 * xattr from the inode itself. 361 * 362 * This gives us a chance to read the on-disk value and convert it. If we 363 * return -EOPNOTSUPP, then vfs_getxattr() will call the i_op handler. 364 * 365 * Note we are not called by vfs_getxattr_alloc(), but that is only called 366 * by the integrity subsystem, which really wants the unconverted values - 367 * so that's good. 368 */ 369int cap_inode_getsecurity(struct inode *inode, const char *name, void **buffer, 370 bool alloc) 371{ 372 int size, ret; 373 kuid_t kroot; 374 u32 nsmagic, magic; 375 uid_t root, mappedroot; 376 char *tmpbuf = NULL; 377 struct vfs_cap_data *cap; 378 struct vfs_ns_cap_data *nscap = NULL; 379 struct dentry *dentry; 380 struct user_namespace *fs_ns; 381 382 if (strcmp(name, "capability") != 0) 383 return -EOPNOTSUPP; 384 385 dentry = d_find_any_alias(inode); 386 if (!dentry) 387 return -EINVAL; 388 389 size = sizeof(struct vfs_ns_cap_data); 390 ret = (int) vfs_getxattr_alloc(dentry, XATTR_NAME_CAPS, 391 &tmpbuf, size, GFP_NOFS); 392 dput(dentry); 393 394 if (ret < 0 || !tmpbuf) { 395 size = ret; 396 goto out_free; 397 } 398 399 fs_ns = inode->i_sb->s_user_ns; 400 cap = (struct vfs_cap_data *) tmpbuf; 401 if (is_v2header((size_t) ret, cap)) { 402 root = 0; 403 } else if (is_v3header((size_t) ret, cap)) { 404 nscap = (struct vfs_ns_cap_data *) tmpbuf; 405 root = le32_to_cpu(nscap->rootid); 406 } else { 407 size = -EINVAL; 408 goto out_free; 409 } 410 411 kroot = make_kuid(fs_ns, root); 412 413 /* If the root kuid maps to a valid uid in current ns, then return 414 * this as a nscap. */ 415 mappedroot = from_kuid(current_user_ns(), kroot); 416 if (mappedroot != (uid_t)-1 && mappedroot != (uid_t)0) { 417 size = sizeof(struct vfs_ns_cap_data); 418 if (alloc) { 419 if (!nscap) { 420 /* v2 -> v3 conversion */ 421 nscap = kzalloc(size, GFP_ATOMIC); 422 if (!nscap) { 423 size = -ENOMEM; 424 goto out_free; 425 } 426 nsmagic = VFS_CAP_REVISION_3; 427 magic = le32_to_cpu(cap->magic_etc); 428 if (magic & VFS_CAP_FLAGS_EFFECTIVE) 429 nsmagic |= VFS_CAP_FLAGS_EFFECTIVE; 430 memcpy(&nscap->data, &cap->data, sizeof(__le32) * 2 * VFS_CAP_U32); 431 nscap->magic_etc = cpu_to_le32(nsmagic); 432 } else { 433 /* use allocated v3 buffer */ 434 tmpbuf = NULL; 435 } 436 nscap->rootid = cpu_to_le32(mappedroot); 437 *buffer = nscap; 438 } 439 goto out_free; 440 } 441 442 if (!rootid_owns_currentns(kroot)) { 443 size = -EOVERFLOW; 444 goto out_free; 445 } 446 447 /* This comes from a parent namespace. Return as a v2 capability */ 448 size = sizeof(struct vfs_cap_data); 449 if (alloc) { 450 if (nscap) { 451 /* v3 -> v2 conversion */ 452 cap = kzalloc(size, GFP_ATOMIC); 453 if (!cap) { 454 size = -ENOMEM; 455 goto out_free; 456 } 457 magic = VFS_CAP_REVISION_2; 458 nsmagic = le32_to_cpu(nscap->magic_etc); 459 if (nsmagic & VFS_CAP_FLAGS_EFFECTIVE) 460 magic |= VFS_CAP_FLAGS_EFFECTIVE; 461 memcpy(&cap->data, &nscap->data, sizeof(__le32) * 2 * VFS_CAP_U32); 462 cap->magic_etc = cpu_to_le32(magic); 463 } else { 464 /* use unconverted v2 */ 465 tmpbuf = NULL; 466 } 467 *buffer = cap; 468 } 469out_free: 470 kfree(tmpbuf); 471 return size; 472} 473 474static kuid_t rootid_from_xattr(const void *value, size_t size, 475 struct user_namespace *task_ns) 476{ 477 const struct vfs_ns_cap_data *nscap = value; 478 uid_t rootid = 0; 479 480 if (size == XATTR_CAPS_SZ_3) 481 rootid = le32_to_cpu(nscap->rootid); 482 483 return make_kuid(task_ns, rootid); 484} 485 486static bool validheader(size_t size, const struct vfs_cap_data *cap) 487{ 488 return is_v2header(size, cap) || is_v3header(size, cap); 489} 490 491/* 492 * User requested a write of security.capability. If needed, update the 493 * xattr to change from v2 to v3, or to fixup the v3 rootid. 494 * 495 * If all is ok, we return the new size, on error return < 0. 496 */ 497int cap_convert_nscap(struct dentry *dentry, void **ivalue, size_t size) 498{ 499 struct vfs_ns_cap_data *nscap; 500 uid_t nsrootid; 501 const struct vfs_cap_data *cap = *ivalue; 502 __u32 magic, nsmagic; 503 struct inode *inode = d_backing_inode(dentry); 504 struct user_namespace *task_ns = current_user_ns(), 505 *fs_ns = inode->i_sb->s_user_ns; 506 kuid_t rootid; 507 size_t newsize; 508 509 if (!*ivalue) 510 return -EINVAL; 511 if (!validheader(size, cap)) 512 return -EINVAL; 513 if (!capable_wrt_inode_uidgid(inode, CAP_SETFCAP)) 514 return -EPERM; 515 if (size == XATTR_CAPS_SZ_2) 516 if (ns_capable(inode->i_sb->s_user_ns, CAP_SETFCAP)) 517 /* user is privileged, just write the v2 */ 518 return size; 519 520 rootid = rootid_from_xattr(*ivalue, size, task_ns); 521 if (!uid_valid(rootid)) 522 return -EINVAL; 523 524 nsrootid = from_kuid(fs_ns, rootid); 525 if (nsrootid == -1) 526 return -EINVAL; 527 528 newsize = sizeof(struct vfs_ns_cap_data); 529 nscap = kmalloc(newsize, GFP_ATOMIC); 530 if (!nscap) 531 return -ENOMEM; 532 nscap->rootid = cpu_to_le32(nsrootid); 533 nsmagic = VFS_CAP_REVISION_3; 534 magic = le32_to_cpu(cap->magic_etc); 535 if (magic & VFS_CAP_FLAGS_EFFECTIVE) 536 nsmagic |= VFS_CAP_FLAGS_EFFECTIVE; 537 nscap->magic_etc = cpu_to_le32(nsmagic); 538 memcpy(&nscap->data, &cap->data, sizeof(__le32) * 2 * VFS_CAP_U32); 539 540 kvfree(*ivalue); 541 *ivalue = nscap; 542 return newsize; 543} 544 545/* 546 * Calculate the new process capability sets from the capability sets attached 547 * to a file. 548 */ 549static inline int bprm_caps_from_vfs_caps(struct cpu_vfs_cap_data *caps, 550 struct linux_binprm *bprm, 551 bool *effective, 552 bool *has_fcap) 553{ 554 struct cred *new = bprm->cred; 555 unsigned i; 556 int ret = 0; 557 558 if (caps->magic_etc & VFS_CAP_FLAGS_EFFECTIVE) 559 *effective = true; 560 561 if (caps->magic_etc & VFS_CAP_REVISION_MASK) 562 *has_fcap = true; 563 564 CAP_FOR_EACH_U32(i) { 565 __u32 permitted = caps->permitted.cap[i]; 566 __u32 inheritable = caps->inheritable.cap[i]; 567 568 /* 569 * pP' = (X & fP) | (pI & fI) 570 * The addition of pA' is handled later. 571 */ 572 new->cap_permitted.cap[i] = 573 (new->cap_bset.cap[i] & permitted) | 574 (new->cap_inheritable.cap[i] & inheritable); 575 576 if (permitted & ~new->cap_permitted.cap[i]) 577 /* insufficient to execute correctly */ 578 ret = -EPERM; 579 } 580 581 /* 582 * For legacy apps, with no internal support for recognizing they 583 * do not have enough capabilities, we return an error if they are 584 * missing some "forced" (aka file-permitted) capabilities. 585 */ 586 return *effective ? ret : 0; 587} 588 589/* 590 * Extract the on-exec-apply capability sets for an executable file. 591 */ 592int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps) 593{ 594 struct inode *inode = d_backing_inode(dentry); 595 __u32 magic_etc; 596 unsigned tocopy, i; 597 int size; 598 struct vfs_ns_cap_data data, *nscaps = &data; 599 struct vfs_cap_data *caps = (struct vfs_cap_data *) &data; 600 kuid_t rootkuid; 601 struct user_namespace *fs_ns; 602 603 memset(cpu_caps, 0, sizeof(struct cpu_vfs_cap_data)); 604 605 if (!inode) 606 return -ENODATA; 607 608 fs_ns = inode->i_sb->s_user_ns; 609 size = __vfs_getxattr((struct dentry *)dentry, inode, 610 XATTR_NAME_CAPS, &data, XATTR_CAPS_SZ); 611 if (size == -ENODATA || size == -EOPNOTSUPP) 612 /* no data, that's ok */ 613 return -ENODATA; 614 615 if (size < 0) 616 return size; 617 618 if (size < sizeof(magic_etc)) 619 return -EINVAL; 620 621 cpu_caps->magic_etc = magic_etc = le32_to_cpu(caps->magic_etc); 622 623 rootkuid = make_kuid(fs_ns, 0); 624 switch (magic_etc & VFS_CAP_REVISION_MASK) { 625 case VFS_CAP_REVISION_1: 626 if (size != XATTR_CAPS_SZ_1) 627 return -EINVAL; 628 tocopy = VFS_CAP_U32_1; 629 break; 630 case VFS_CAP_REVISION_2: 631 if (size != XATTR_CAPS_SZ_2) 632 return -EINVAL; 633 tocopy = VFS_CAP_U32_2; 634 break; 635 case VFS_CAP_REVISION_3: 636 if (size != XATTR_CAPS_SZ_3) 637 return -EINVAL; 638 tocopy = VFS_CAP_U32_3; 639 rootkuid = make_kuid(fs_ns, le32_to_cpu(nscaps->rootid)); 640 break; 641 642 default: 643 return -EINVAL; 644 } 645 /* Limit the caps to the mounter of the filesystem 646 * or the more limited uid specified in the xattr. 647 */ 648 if (!rootid_owns_currentns(rootkuid)) 649 return -ENODATA; 650 651 CAP_FOR_EACH_U32(i) { 652 if (i >= tocopy) 653 break; 654 cpu_caps->permitted.cap[i] = le32_to_cpu(caps->data[i].permitted); 655 cpu_caps->inheritable.cap[i] = le32_to_cpu(caps->data[i].inheritable); 656 } 657 658 cpu_caps->permitted.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK; 659 cpu_caps->inheritable.cap[CAP_LAST_U32] &= CAP_LAST_U32_VALID_MASK; 660 661 cpu_caps->rootid = rootkuid; 662 663 return 0; 664} 665 666/* 667 * Attempt to get the on-exec apply capability sets for an executable file from 668 * its xattrs and, if present, apply them to the proposed credentials being 669 * constructed by execve(). 670 */ 671static int get_file_caps(struct linux_binprm *bprm, struct file *file, 672 bool *effective, bool *has_fcap) 673{ 674 int rc = 0; 675 struct cpu_vfs_cap_data vcaps; 676 677 cap_clear(bprm->cred->cap_permitted); 678 679 if (!file_caps_enabled) 680 return 0; 681 682 if (!mnt_may_suid(file->f_path.mnt)) 683 return 0; 684 685 /* 686 * This check is redundant with mnt_may_suid() but is kept to make 687 * explicit that capability bits are limited to s_user_ns and its 688 * descendants. 689 */ 690 if (!current_in_userns(file->f_path.mnt->mnt_sb->s_user_ns)) 691 return 0; 692 693 rc = get_vfs_caps_from_disk(file->f_path.dentry, &vcaps); 694 if (rc < 0) { 695 if (rc == -EINVAL) 696 printk(KERN_NOTICE "Invalid argument reading file caps for %s\n", 697 bprm->filename); 698 else if (rc == -ENODATA) 699 rc = 0; 700 goto out; 701 } 702 703 rc = bprm_caps_from_vfs_caps(&vcaps, bprm, effective, has_fcap); 704 705out: 706 if (rc) 707 cap_clear(bprm->cred->cap_permitted); 708 709 return rc; 710} 711 712static inline bool root_privileged(void) { return !issecure(SECURE_NOROOT); } 713 714static inline bool __is_real(kuid_t uid, struct cred *cred) 715{ return uid_eq(cred->uid, uid); } 716 717static inline bool __is_eff(kuid_t uid, struct cred *cred) 718{ return uid_eq(cred->euid, uid); } 719 720static inline bool __is_suid(kuid_t uid, struct cred *cred) 721{ return !__is_real(uid, cred) && __is_eff(uid, cred); } 722 723/* 724 * handle_privileged_root - Handle case of privileged root 725 * @bprm: The execution parameters, including the proposed creds 726 * @has_fcap: Are any file capabilities set? 727 * @effective: Do we have effective root privilege? 728 * @root_uid: This namespace' root UID WRT initial USER namespace 729 * 730 * Handle the case where root is privileged and hasn't been neutered by 731 * SECURE_NOROOT. If file capabilities are set, they won't be combined with 732 * set UID root and nothing is changed. If we are root, cap_permitted is 733 * updated. If we have become set UID root, the effective bit is set. 734 */ 735static void handle_privileged_root(struct linux_binprm *bprm, bool has_fcap, 736 bool *effective, kuid_t root_uid) 737{ 738 const struct cred *old = current_cred(); 739 struct cred *new = bprm->cred; 740 741 if (!root_privileged()) 742 return; 743 /* 744 * If the legacy file capability is set, then don't set privs 745 * for a setuid root binary run by a non-root user. Do set it 746 * for a root user just to cause least surprise to an admin. 747 */ 748 if (has_fcap && __is_suid(root_uid, new)) { 749 warn_setuid_and_fcaps_mixed(bprm->filename); 750 return; 751 } 752 /* 753 * To support inheritance of root-permissions and suid-root 754 * executables under compatibility mode, we override the 755 * capability sets for the file. 756 */ 757 if (__is_eff(root_uid, new) || __is_real(root_uid, new)) { 758 /* pP' = (cap_bset & ~0) | (pI & ~0) */ 759 new->cap_permitted = cap_combine(old->cap_bset, 760 old->cap_inheritable); 761 } 762 /* 763 * If only the real uid is 0, we do not set the effective bit. 764 */ 765 if (__is_eff(root_uid, new)) 766 *effective = true; 767} 768 769#define __cap_gained(field, target, source) \ 770 !cap_issubset(target->cap_##field, source->cap_##field) 771#define __cap_grew(target, source, cred) \ 772 !cap_issubset(cred->cap_##target, cred->cap_##source) 773#define __cap_full(field, cred) \ 774 cap_issubset(CAP_FULL_SET, cred->cap_##field) 775 776static inline bool __is_setuid(struct cred *new, const struct cred *old) 777{ return !uid_eq(new->euid, old->uid); } 778 779static inline bool __is_setgid(struct cred *new, const struct cred *old) 780{ return !gid_eq(new->egid, old->gid); } 781 782/* 783 * 1) Audit candidate if current->cap_effective is set 784 * 785 * We do not bother to audit if 3 things are true: 786 * 1) cap_effective has all caps 787 * 2) we became root *OR* are were already root 788 * 3) root is supposed to have all caps (SECURE_NOROOT) 789 * Since this is just a normal root execing a process. 790 * 791 * Number 1 above might fail if you don't have a full bset, but I think 792 * that is interesting information to audit. 793 * 794 * A number of other conditions require logging: 795 * 2) something prevented setuid root getting all caps 796 * 3) non-setuid root gets fcaps 797 * 4) non-setuid root gets ambient 798 */ 799static inline bool nonroot_raised_pE(struct cred *new, const struct cred *old, 800 kuid_t root, bool has_fcap) 801{ 802 bool ret = false; 803 804 if ((__cap_grew(effective, ambient, new) && 805 !(__cap_full(effective, new) && 806 (__is_eff(root, new) || __is_real(root, new)) && 807 root_privileged())) || 808 (root_privileged() && 809 __is_suid(root, new) && 810 !__cap_full(effective, new)) || 811 (!__is_setuid(new, old) && 812 ((has_fcap && 813 __cap_gained(permitted, new, old)) || 814 __cap_gained(ambient, new, old)))) 815 816 ret = true; 817 818 return ret; 819} 820 821/** 822 * cap_bprm_creds_from_file - Set up the proposed credentials for execve(). 823 * @bprm: The execution parameters, including the proposed creds 824 * @file: The file to pull the credentials from 825 * 826 * Set up the proposed credentials for a new execution context being 827 * constructed by execve(). The proposed creds in @bprm->cred is altered, 828 * which won't take effect immediately. Returns 0 if successful, -ve on error. 829 */ 830int cap_bprm_creds_from_file(struct linux_binprm *bprm, struct file *file) 831{ 832 /* Process setpcap binaries and capabilities for uid 0 */ 833 const struct cred *old = current_cred(); 834 struct cred *new = bprm->cred; 835 bool effective = false, has_fcap = false, is_setid; 836 int ret; 837 kuid_t root_uid; 838 839 if (WARN_ON(!cap_ambient_invariant_ok(old))) 840 return -EPERM; 841 842 ret = get_file_caps(bprm, file, &effective, &has_fcap); 843 if (ret < 0) 844 return ret; 845 846 root_uid = make_kuid(new->user_ns, 0); 847 848 handle_privileged_root(bprm, has_fcap, &effective, root_uid); 849 850 /* if we have fs caps, clear dangerous personality flags */ 851 if (__cap_gained(permitted, new, old)) 852 bprm->per_clear |= PER_CLEAR_ON_SETID; 853 854 /* Don't let someone trace a set[ug]id/setpcap binary with the revised 855 * credentials unless they have the appropriate permit. 856 * 857 * In addition, if NO_NEW_PRIVS, then ensure we get no new privs. 858 */ 859 is_setid = __is_setuid(new, old) || __is_setgid(new, old); 860 861 if ((is_setid || __cap_gained(permitted, new, old)) && 862 ((bprm->unsafe & ~LSM_UNSAFE_PTRACE) || 863 !ptracer_capable(current, new->user_ns))) { 864 /* downgrade; they get no more than they had, and maybe less */ 865 if (!ns_capable(new->user_ns, CAP_SETUID) || 866 (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS)) { 867 new->euid = new->uid; 868 new->egid = new->gid; 869 } 870 new->cap_permitted = cap_intersect(new->cap_permitted, 871 old->cap_permitted); 872 } 873 874 new->suid = new->fsuid = new->euid; 875 new->sgid = new->fsgid = new->egid; 876 877 /* File caps or setid cancels ambient. */ 878 if (has_fcap || is_setid) 879 cap_clear(new->cap_ambient); 880 881 /* 882 * Now that we've computed pA', update pP' to give: 883 * pP' = (X & fP) | (pI & fI) | pA' 884 */ 885 new->cap_permitted = cap_combine(new->cap_permitted, new->cap_ambient); 886 887 /* 888 * Set pE' = (fE ? pP' : pA'). Because pA' is zero if fE is set, 889 * this is the same as pE' = (fE ? pP' : 0) | pA'. 890 */ 891 if (effective) 892 new->cap_effective = new->cap_permitted; 893 else 894 new->cap_effective = new->cap_ambient; 895 896 if (WARN_ON(!cap_ambient_invariant_ok(new))) 897 return -EPERM; 898 899 if (nonroot_raised_pE(new, old, root_uid, has_fcap)) { 900 ret = audit_log_bprm_fcaps(bprm, new, old); 901 if (ret < 0) 902 return ret; 903 } 904 905 new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); 906 907 if (WARN_ON(!cap_ambient_invariant_ok(new))) 908 return -EPERM; 909 910 /* Check for privilege-elevated exec. */ 911 if (is_setid || 912 (!__is_real(root_uid, new) && 913 (effective || 914 __cap_grew(permitted, ambient, new)))) 915 bprm->secureexec = 1; 916 917 return 0; 918} 919 920/** 921 * cap_inode_setxattr - Determine whether an xattr may be altered 922 * @dentry: The inode/dentry being altered 923 * @name: The name of the xattr to be changed 924 * @value: The value that the xattr will be changed to 925 * @size: The size of value 926 * @flags: The replacement flag 927 * 928 * Determine whether an xattr may be altered or set on an inode, returning 0 if 929 * permission is granted, -ve if denied. 930 * 931 * This is used to make sure security xattrs don't get updated or set by those 932 * who aren't privileged to do so. 933 */ 934int cap_inode_setxattr(struct dentry *dentry, const char *name, 935 const void *value, size_t size, int flags) 936{ 937 struct user_namespace *user_ns = dentry->d_sb->s_user_ns; 938 939 /* Ignore non-security xattrs */ 940 if (strncmp(name, XATTR_SECURITY_PREFIX, 941 XATTR_SECURITY_PREFIX_LEN) != 0) 942 return 0; 943 944 /* 945 * For XATTR_NAME_CAPS the check will be done in 946 * cap_convert_nscap(), called by setxattr() 947 */ 948 if (strcmp(name, XATTR_NAME_CAPS) == 0) 949 return 0; 950 951 if (!ns_capable(user_ns, CAP_SYS_ADMIN)) 952 return -EPERM; 953 return 0; 954} 955 956/** 957 * cap_inode_removexattr - Determine whether an xattr may be removed 958 * @dentry: The inode/dentry being altered 959 * @name: The name of the xattr to be changed 960 * 961 * Determine whether an xattr may be removed from an inode, returning 0 if 962 * permission is granted, -ve if denied. 963 * 964 * This is used to make sure security xattrs don't get removed by those who 965 * aren't privileged to remove them. 966 */ 967int cap_inode_removexattr(struct dentry *dentry, const char *name) 968{ 969 struct user_namespace *user_ns = dentry->d_sb->s_user_ns; 970 971 /* Ignore non-security xattrs */ 972 if (strncmp(name, XATTR_SECURITY_PREFIX, 973 XATTR_SECURITY_PREFIX_LEN) != 0) 974 return 0; 975 976 if (strcmp(name, XATTR_NAME_CAPS) == 0) { 977 /* security.capability gets namespaced */ 978 struct inode *inode = d_backing_inode(dentry); 979 if (!inode) 980 return -EINVAL; 981 if (!capable_wrt_inode_uidgid(inode, CAP_SETFCAP)) 982 return -EPERM; 983 return 0; 984 } 985 986 if (!ns_capable(user_ns, CAP_SYS_ADMIN)) 987 return -EPERM; 988 return 0; 989} 990 991/* 992 * cap_emulate_setxuid() fixes the effective / permitted capabilities of 993 * a process after a call to setuid, setreuid, or setresuid. 994 * 995 * 1) When set*uiding _from_ one of {r,e,s}uid == 0 _to_ all of 996 * {r,e,s}uid != 0, the permitted and effective capabilities are 997 * cleared. 998 * 999 * 2) When set*uiding _from_ euid == 0 _to_ euid != 0, the effective 1000 * capabilities of the process are cleared. 1001 * 1002 * 3) When set*uiding _from_ euid != 0 _to_ euid == 0, the effective 1003 * capabilities are set to the permitted capabilities. 1004 * 1005 * fsuid is handled elsewhere. fsuid == 0 and {r,e,s}uid!= 0 should 1006 * never happen. 1007 * 1008 * -astor 1009 * 1010 * cevans - New behaviour, Oct '99 1011 * A process may, via prctl(), elect to keep its capabilities when it 1012 * calls setuid() and switches away from uid==0. Both permitted and 1013 * effective sets will be retained. 1014 * Without this change, it was impossible for a daemon to drop only some 1015 * of its privilege. The call to setuid(!=0) would drop all privileges! 1016 * Keeping uid 0 is not an option because uid 0 owns too many vital 1017 * files.. 1018 * Thanks to Olaf Kirch and Peter Benie for spotting this. 1019 */ 1020static inline void cap_emulate_setxuid(struct cred *new, const struct cred *old) 1021{ 1022 kuid_t root_uid = make_kuid(old->user_ns, 0); 1023 1024 if ((uid_eq(old->uid, root_uid) || 1025 uid_eq(old->euid, root_uid) || 1026 uid_eq(old->suid, root_uid)) && 1027 (!uid_eq(new->uid, root_uid) && 1028 !uid_eq(new->euid, root_uid) && 1029 !uid_eq(new->suid, root_uid))) { 1030 if (!issecure(SECURE_KEEP_CAPS)) { 1031 cap_clear(new->cap_permitted); 1032 cap_clear(new->cap_effective); 1033 } 1034 1035 /* 1036 * Pre-ambient programs expect setresuid to nonroot followed 1037 * by exec to drop capabilities. We should make sure that 1038 * this remains the case. 1039 */ 1040 cap_clear(new->cap_ambient); 1041 } 1042 if (uid_eq(old->euid, root_uid) && !uid_eq(new->euid, root_uid)) 1043 cap_clear(new->cap_effective); 1044 if (!uid_eq(old->euid, root_uid) && uid_eq(new->euid, root_uid)) 1045 new->cap_effective = new->cap_permitted; 1046} 1047 1048/** 1049 * cap_task_fix_setuid - Fix up the results of setuid() call 1050 * @new: The proposed credentials 1051 * @old: The current task's current credentials 1052 * @flags: Indications of what has changed 1053 * 1054 * Fix up the results of setuid() call before the credential changes are 1055 * actually applied, returning 0 to grant the changes, -ve to deny them. 1056 */ 1057int cap_task_fix_setuid(struct cred *new, const struct cred *old, int flags) 1058{ 1059 switch (flags) { 1060 case LSM_SETID_RE: 1061 case LSM_SETID_ID: 1062 case LSM_SETID_RES: 1063 /* juggle the capabilities to follow [RES]UID changes unless 1064 * otherwise suppressed */ 1065 if (!issecure(SECURE_NO_SETUID_FIXUP)) 1066 cap_emulate_setxuid(new, old); 1067 break; 1068 1069 case LSM_SETID_FS: 1070 /* juggle the capabilties to follow FSUID changes, unless 1071 * otherwise suppressed 1072 * 1073 * FIXME - is fsuser used for all CAP_FS_MASK capabilities? 1074 * if not, we might be a bit too harsh here. 1075 */ 1076 if (!issecure(SECURE_NO_SETUID_FIXUP)) { 1077 kuid_t root_uid = make_kuid(old->user_ns, 0); 1078 if (uid_eq(old->fsuid, root_uid) && !uid_eq(new->fsuid, root_uid)) 1079 new->cap_effective = 1080 cap_drop_fs_set(new->cap_effective); 1081 1082 if (!uid_eq(old->fsuid, root_uid) && uid_eq(new->fsuid, root_uid)) 1083 new->cap_effective = 1084 cap_raise_fs_set(new->cap_effective, 1085 new->cap_permitted); 1086 } 1087 break; 1088 1089 default: 1090 return -EINVAL; 1091 } 1092 1093 return 0; 1094} 1095 1096/* 1097 * Rationale: code calling task_setscheduler, task_setioprio, and 1098 * task_setnice, assumes that 1099 * . if capable(cap_sys_nice), then those actions should be allowed 1100 * . if not capable(cap_sys_nice), but acting on your own processes, 1101 * then those actions should be allowed 1102 * This is insufficient now since you can call code without suid, but 1103 * yet with increased caps. 1104 * So we check for increased caps on the target process. 1105 */ 1106static int cap_safe_nice(struct task_struct *p) 1107{ 1108 int is_subset, ret = 0; 1109 1110 rcu_read_lock(); 1111 is_subset = cap_issubset(__task_cred(p)->cap_permitted, 1112 current_cred()->cap_permitted); 1113 if (!is_subset && !ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) 1114 ret = -EPERM; 1115 rcu_read_unlock(); 1116 1117 return ret; 1118} 1119 1120/** 1121 * cap_task_setscheduler - Detemine if scheduler policy change is permitted 1122 * @p: The task to affect 1123 * 1124 * Detemine if the requested scheduler policy change is permitted for the 1125 * specified task, returning 0 if permission is granted, -ve if denied. 1126 */ 1127int cap_task_setscheduler(struct task_struct *p) 1128{ 1129 return cap_safe_nice(p); 1130} 1131 1132/** 1133 * cap_task_ioprio - Detemine if I/O priority change is permitted 1134 * @p: The task to affect 1135 * @ioprio: The I/O priority to set 1136 * 1137 * Detemine if the requested I/O priority change is permitted for the specified 1138 * task, returning 0 if permission is granted, -ve if denied. 1139 */ 1140int cap_task_setioprio(struct task_struct *p, int ioprio) 1141{ 1142 return cap_safe_nice(p); 1143} 1144 1145/** 1146 * cap_task_ioprio - Detemine if task priority change is permitted 1147 * @p: The task to affect 1148 * @nice: The nice value to set 1149 * 1150 * Detemine if the requested task priority change is permitted for the 1151 * specified task, returning 0 if permission is granted, -ve if denied. 1152 */ 1153int cap_task_setnice(struct task_struct *p, int nice) 1154{ 1155 return cap_safe_nice(p); 1156} 1157 1158/* 1159 * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from 1160 * the current task's bounding set. Returns 0 on success, -ve on error. 1161 */ 1162static int cap_prctl_drop(unsigned long cap) 1163{ 1164 struct cred *new; 1165 1166 if (!ns_capable(current_user_ns(), CAP_SETPCAP)) 1167 return -EPERM; 1168 if (!cap_valid(cap)) 1169 return -EINVAL; 1170 1171 new = prepare_creds(); 1172 if (!new) 1173 return -ENOMEM; 1174 cap_lower(new->cap_bset, cap); 1175 return commit_creds(new); 1176} 1177 1178/** 1179 * cap_task_prctl - Implement process control functions for this security module 1180 * @option: The process control function requested 1181 * @arg2, @arg3, @arg4, @arg5: The argument data for this function 1182 * 1183 * Allow process control functions (sys_prctl()) to alter capabilities; may 1184 * also deny access to other functions not otherwise implemented here. 1185 * 1186 * Returns 0 or +ve on success, -ENOSYS if this function is not implemented 1187 * here, other -ve on error. If -ENOSYS is returned, sys_prctl() and other LSM 1188 * modules will consider performing the function. 1189 */ 1190int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, 1191 unsigned long arg4, unsigned long arg5) 1192{ 1193 const struct cred *old = current_cred(); 1194 struct cred *new; 1195 1196 switch (option) { 1197 case PR_CAPBSET_READ: 1198 if (!cap_valid(arg2)) 1199 return -EINVAL; 1200 return !!cap_raised(old->cap_bset, arg2); 1201 1202 case PR_CAPBSET_DROP: 1203 return cap_prctl_drop(arg2); 1204 1205 /* 1206 * The next four prctl's remain to assist with transitioning a 1207 * system from legacy UID=0 based privilege (when filesystem 1208 * capabilities are not in use) to a system using filesystem 1209 * capabilities only - as the POSIX.1e draft intended. 1210 * 1211 * Note: 1212 * 1213 * PR_SET_SECUREBITS = 1214 * issecure_mask(SECURE_KEEP_CAPS_LOCKED) 1215 * | issecure_mask(SECURE_NOROOT) 1216 * | issecure_mask(SECURE_NOROOT_LOCKED) 1217 * | issecure_mask(SECURE_NO_SETUID_FIXUP) 1218 * | issecure_mask(SECURE_NO_SETUID_FIXUP_LOCKED) 1219 * 1220 * will ensure that the current process and all of its 1221 * children will be locked into a pure 1222 * capability-based-privilege environment. 1223 */ 1224 case PR_SET_SECUREBITS: 1225 if ((((old->securebits & SECURE_ALL_LOCKS) >> 1) 1226 & (old->securebits ^ arg2)) /*[1]*/ 1227 || ((old->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/ 1228 || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ 1229 || (cap_capable(current_cred(), 1230 current_cred()->user_ns, 1231 CAP_SETPCAP, 1232 CAP_OPT_NONE) != 0) /*[4]*/ 1233 /* 1234 * [1] no changing of bits that are locked 1235 * [2] no unlocking of locks 1236 * [3] no setting of unsupported bits 1237 * [4] doing anything requires privilege (go read about 1238 * the "sendmail capabilities bug") 1239 */ 1240 ) 1241 /* cannot change a locked bit */ 1242 return -EPERM; 1243 1244 new = prepare_creds(); 1245 if (!new) 1246 return -ENOMEM; 1247 new->securebits = arg2; 1248 return commit_creds(new); 1249 1250 case PR_GET_SECUREBITS: 1251 return old->securebits; 1252 1253 case PR_GET_KEEPCAPS: 1254 return !!issecure(SECURE_KEEP_CAPS); 1255 1256 case PR_SET_KEEPCAPS: 1257 if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */ 1258 return -EINVAL; 1259 if (issecure(SECURE_KEEP_CAPS_LOCKED)) 1260 return -EPERM; 1261 1262 new = prepare_creds(); 1263 if (!new) 1264 return -ENOMEM; 1265 if (arg2) 1266 new->securebits |= issecure_mask(SECURE_KEEP_CAPS); 1267 else 1268 new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); 1269 return commit_creds(new); 1270 1271 case PR_CAP_AMBIENT: 1272 if (arg2 == PR_CAP_AMBIENT_CLEAR_ALL) { 1273 if (arg3 | arg4 | arg5) 1274 return -EINVAL; 1275 1276 new = prepare_creds(); 1277 if (!new) 1278 return -ENOMEM; 1279 cap_clear(new->cap_ambient); 1280 return commit_creds(new); 1281 } 1282 1283 if (((!cap_valid(arg3)) | arg4 | arg5)) 1284 return -EINVAL; 1285 1286 if (arg2 == PR_CAP_AMBIENT_IS_SET) { 1287 return !!cap_raised(current_cred()->cap_ambient, arg3); 1288 } else if (arg2 != PR_CAP_AMBIENT_RAISE && 1289 arg2 != PR_CAP_AMBIENT_LOWER) { 1290 return -EINVAL; 1291 } else { 1292 if (arg2 == PR_CAP_AMBIENT_RAISE && 1293 (!cap_raised(current_cred()->cap_permitted, arg3) || 1294 !cap_raised(current_cred()->cap_inheritable, 1295 arg3) || 1296 issecure(SECURE_NO_CAP_AMBIENT_RAISE))) 1297 return -EPERM; 1298 1299 new = prepare_creds(); 1300 if (!new) 1301 return -ENOMEM; 1302 if (arg2 == PR_CAP_AMBIENT_RAISE) 1303 cap_raise(new->cap_ambient, arg3); 1304 else 1305 cap_lower(new->cap_ambient, arg3); 1306 return commit_creds(new); 1307 } 1308 1309 default: 1310 /* No functionality available - continue with default */ 1311 return -ENOSYS; 1312 } 1313} 1314 1315/** 1316 * cap_vm_enough_memory - Determine whether a new virtual mapping is permitted 1317 * @mm: The VM space in which the new mapping is to be made 1318 * @pages: The size of the mapping 1319 * 1320 * Determine whether the allocation of a new virtual mapping by the current 1321 * task is permitted, returning 1 if permission is granted, 0 if not. 1322 */ 1323int cap_vm_enough_memory(struct mm_struct *mm, long pages) 1324{ 1325 int cap_sys_admin = 0; 1326 1327 if (cap_capable(current_cred(), &init_user_ns, 1328 CAP_SYS_ADMIN, CAP_OPT_NOAUDIT) == 0) 1329 cap_sys_admin = 1; 1330 1331 return cap_sys_admin; 1332} 1333 1334/* 1335 * cap_mmap_addr - check if able to map given addr 1336 * @addr: address attempting to be mapped 1337 * 1338 * If the process is attempting to map memory below dac_mmap_min_addr they need 1339 * CAP_SYS_RAWIO. The other parameters to this function are unused by the 1340 * capability security module. Returns 0 if this mapping should be allowed 1341 * -EPERM if not. 1342 */ 1343int cap_mmap_addr(unsigned long addr) 1344{ 1345 int ret = 0; 1346 1347 if (addr < dac_mmap_min_addr) { 1348 ret = cap_capable(current_cred(), &init_user_ns, CAP_SYS_RAWIO, 1349 CAP_OPT_NONE); 1350 /* set PF_SUPERPRIV if it turns out we allow the low mmap */ 1351 if (ret == 0) 1352 current->flags |= PF_SUPERPRIV; 1353 } 1354 return ret; 1355} 1356 1357int cap_mmap_file(struct file *file, unsigned long reqprot, 1358 unsigned long prot, unsigned long flags) 1359{ 1360 return 0; 1361} 1362 1363#ifdef CONFIG_SECURITY 1364 1365static struct security_hook_list capability_hooks[] __lsm_ro_after_init = { 1366 LSM_HOOK_INIT(capable, cap_capable), 1367 LSM_HOOK_INIT(settime, cap_settime), 1368 LSM_HOOK_INIT(ptrace_access_check, cap_ptrace_access_check), 1369 LSM_HOOK_INIT(ptrace_traceme, cap_ptrace_traceme), 1370 LSM_HOOK_INIT(capget, cap_capget), 1371 LSM_HOOK_INIT(capset, cap_capset), 1372 LSM_HOOK_INIT(bprm_creds_from_file, cap_bprm_creds_from_file), 1373 LSM_HOOK_INIT(inode_need_killpriv, cap_inode_need_killpriv), 1374 LSM_HOOK_INIT(inode_killpriv, cap_inode_killpriv), 1375 LSM_HOOK_INIT(inode_getsecurity, cap_inode_getsecurity), 1376 LSM_HOOK_INIT(mmap_addr, cap_mmap_addr), 1377 LSM_HOOK_INIT(mmap_file, cap_mmap_file), 1378 LSM_HOOK_INIT(task_fix_setuid, cap_task_fix_setuid), 1379 LSM_HOOK_INIT(task_prctl, cap_task_prctl), 1380 LSM_HOOK_INIT(task_setscheduler, cap_task_setscheduler), 1381 LSM_HOOK_INIT(task_setioprio, cap_task_setioprio), 1382 LSM_HOOK_INIT(task_setnice, cap_task_setnice), 1383 LSM_HOOK_INIT(vm_enough_memory, cap_vm_enough_memory), 1384}; 1385 1386static int __init capability_init(void) 1387{ 1388 security_add_hooks(capability_hooks, ARRAY_SIZE(capability_hooks), 1389 "capability"); 1390 return 0; 1391} 1392 1393DEFINE_LSM(capability) = { 1394 .name = "capability", 1395 .order = LSM_ORDER_FIRST, 1396 .init = capability_init, 1397}; 1398 1399#endif /* CONFIG_SECURITY */ 1400