1 /*
2 * Linux Security Module interfaces
3 *
4 * Copyright (C) 2001 WireX Communications, Inc <chris@wirex.com>
5 * Copyright (C) 2001 Greg Kroah-Hartman <greg@kroah.com>
6 * Copyright (C) 2001 Networks Associates Technology, Inc <ssmalley@nai.com>
7 * Copyright (C) 2001 James Morris <jmorris@intercode.com.au>
8 * Copyright (C) 2001 Silicon Graphics, Inc. (Trust Technology Group)
9 * Copyright (C) 2015 Intel Corporation.
10 * Copyright (C) 2015 Casey Schaufler <casey@schaufler-ca.com>
11 * Copyright (C) 2016 Mellanox Techonologies
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 * Due to this file being licensed under the GPL there is controversy over
19 * whether this permits you to write a module that #includes this file
20 * without placing your module under the GPL. Please consult a lawyer for
21 * advice before doing this.
22 *
23 */
24
25 #ifndef __LINUX_LSM_HOOKS_H
26 #define __LINUX_LSM_HOOKS_H
27
28 #include <linux/security.h>
29 #include <linux/init.h>
30 #include <linux/rculist.h>
31
32 /**
33 * union security_list_options - Linux Security Module hook function list
34 *
35 * Security hooks for program execution operations.
36 *
37 * @bprm_creds_for_exec:
38 * If the setup in prepare_exec_creds did not setup @bprm->cred->security
39 * properly for executing @bprm->file, update the LSM's portion of
40 * @bprm->cred->security to be what commit_creds needs to install for the
41 * new program. This hook may also optionally check permissions
42 * (e.g. for transitions between security domains).
43 * The hook must set @bprm->secureexec to 1 if AT_SECURE should be set to
44 * request libc enable secure mode.
45 * @bprm contains the linux_binprm structure.
46 * Return 0 if the hook is successful and permission is granted.
47 * @bprm_creds_from_file:
48 * If @file is setpcap, suid, sgid or otherwise marked to change
49 * privilege upon exec, update @bprm->cred to reflect that change.
50 * This is called after finding the binary that will be executed.
51 * without an interpreter. This ensures that the credentials will not
52 * be derived from a script that the binary will need to reopen, which
53 * when reopend may end up being a completely different file. This
54 * hook may also optionally check permissions (e.g. for transitions
55 * between security domains).
56 * The hook must set @bprm->secureexec to 1 if AT_SECURE should be set to
57 * request libc enable secure mode.
58 * The hook must add to @bprm->per_clear any personality flags that
59 * should be cleared from current->personality.
60 * @bprm contains the linux_binprm structure.
61 * Return 0 if the hook is successful and permission is granted.
62 * @bprm_check_security:
63 * This hook mediates the point when a search for a binary handler will
64 * begin. It allows a check against the @bprm->cred->security value
65 * which was set in the preceding creds_for_exec call. The argv list and
66 * envp list are reliably available in @bprm. This hook may be called
67 * multiple times during a single execve.
68 * @bprm contains the linux_binprm structure.
69 * Return 0 if the hook is successful and permission is granted.
70 * @bprm_committing_creds:
71 * Prepare to install the new security attributes of a process being
72 * transformed by an execve operation, based on the old credentials
73 * pointed to by @current->cred and the information set in @bprm->cred by
74 * the bprm_creds_for_exec hook. @bprm points to the linux_binprm
75 * structure. This hook is a good place to perform state changes on the
76 * process such as closing open file descriptors to which access will no
77 * longer be granted when the attributes are changed. This is called
78 * immediately before commit_creds().
79 * @bprm_committed_creds:
80 * Tidy up after the installation of the new security attributes of a
81 * process being transformed by an execve operation. The new credentials
82 * have, by this point, been set to @current->cred. @bprm points to the
83 * linux_binprm structure. This hook is a good place to perform state
84 * changes on the process such as clearing out non-inheritable signal
85 * state. This is called immediately after commit_creds().
86 *
87 * Security hooks for mount using fs_context.
88 * [See also Documentation/filesystems/mount_api.rst]
89 *
90 * @fs_context_dup:
91 * Allocate and attach a security structure to sc->security. This pointer
92 * is initialised to NULL by the caller.
93 * @fc indicates the new filesystem context.
94 * @src_fc indicates the original filesystem context.
95 * @fs_context_parse_param:
96 * Userspace provided a parameter to configure a superblock. The LSM may
97 * reject it with an error and may use it for itself, in which case it
98 * should return 0; otherwise it should return -ENOPARAM to pass it on to
99 * the filesystem.
100 * @fc indicates the filesystem context.
101 * @param The parameter
102 *
103 * Security hooks for filesystem operations.
104 *
105 * @sb_alloc_security:
106 * Allocate and attach a security structure to the sb->s_security field.
107 * The s_security field is initialized to NULL when the structure is
108 * allocated.
109 * @sb contains the super_block structure to be modified.
110 * Return 0 if operation was successful.
111 * @sb_free_security:
112 * Deallocate and clear the sb->s_security field.
113 * @sb contains the super_block structure to be modified.
114 * @sb_free_mnt_opts:
115 * Free memory associated with @mnt_ops.
116 * @sb_eat_lsm_opts:
117 * Eat (scan @orig options) and save them in @mnt_opts.
118 * @sb_statfs:
119 * Check permission before obtaining filesystem statistics for the @mnt
120 * mountpoint.
121 * @dentry is a handle on the superblock for the filesystem.
122 * Return 0 if permission is granted.
123 * @sb_mount:
124 * Check permission before an object specified by @dev_name is mounted on
125 * the mount point named by @nd. For an ordinary mount, @dev_name
126 * identifies a device if the file system type requires a device. For a
127 * remount (@flags & MS_REMOUNT), @dev_name is irrelevant. For a
128 * loopback/bind mount (@flags & MS_BIND), @dev_name identifies the
129 * pathname of the object being mounted.
130 * @dev_name contains the name for object being mounted.
131 * @path contains the path for mount point object.
132 * @type contains the filesystem type.
133 * @flags contains the mount flags.
134 * @data contains the filesystem-specific data.
135 * Return 0 if permission is granted.
136 * @sb_copy_data:
137 * Allow mount option data to be copied prior to parsing by the filesystem,
138 * so that the security module can extract security-specific mount
139 * options cleanly (a filesystem may modify the data e.g. with strsep()).
140 * This also allows the original mount data to be stripped of security-
141 * specific options to avoid having to make filesystems aware of them.
142 * @orig the original mount data copied from userspace.
143 * @copy copied data which will be passed to the security module.
144 * Returns 0 if the copy was successful.
145 * @sb_remount:
146 * Extracts security system specific mount options and verifies no changes
147 * are being made to those options.
148 * @sb superblock being remounted
149 * @data contains the filesystem-specific data.
150 * Return 0 if permission is granted.
151 * @sb_kern_mount:
152 * Mount this @sb if allowed by permissions.
153 * @sb_show_options:
154 * Show (print on @m) mount options for this @sb.
155 * @sb_umount:
156 * Check permission before the @mnt file system is unmounted.
157 * @mnt contains the mounted file system.
158 * @flags contains the unmount flags, e.g. MNT_FORCE.
159 * Return 0 if permission is granted.
160 * @sb_pivotroot:
161 * Check permission before pivoting the root filesystem.
162 * @old_path contains the path for the new location of the
163 * current root (put_old).
164 * @new_path contains the path for the new root (new_root).
165 * Return 0 if permission is granted.
166 * @sb_set_mnt_opts:
167 * Set the security relevant mount options used for a superblock
168 * @sb the superblock to set security mount options for
169 * @opts binary data structure containing all lsm mount data
170 * @sb_clone_mnt_opts:
171 * Copy all security options from a given superblock to another
172 * @oldsb old superblock which contain information to clone
173 * @newsb new superblock which needs filled in
174 * @sb_add_mnt_opt:
175 * Add one mount @option to @mnt_opts.
176 * @sb_parse_opts_str:
177 * Parse a string of security data filling in the opts structure
178 * @options string containing all mount options known by the LSM
179 * @opts binary data structure usable by the LSM
180 * @move_mount:
181 * Check permission before a mount is moved.
182 * @from_path indicates the mount that is going to be moved.
183 * @to_path indicates the mountpoint that will be mounted upon.
184 * @dentry_init_security:
185 * Compute a context for a dentry as the inode is not yet available
186 * since NFSv4 has no label backed by an EA anyway.
187 * @dentry dentry to use in calculating the context.
188 * @mode mode used to determine resource type.
189 * @name name of the last path component used to create file
190 * @ctx pointer to place the pointer to the resulting context in.
191 * @ctxlen point to place the length of the resulting context.
192 * @dentry_create_files_as:
193 * Compute a context for a dentry as the inode is not yet available
194 * and set that context in passed in creds so that new files are
195 * created using that context. Context is calculated using the
196 * passed in creds and not the creds of the caller.
197 * @dentry dentry to use in calculating the context.
198 * @mode mode used to determine resource type.
199 * @name name of the last path component used to create file
200 * @old creds which should be used for context calculation
201 * @new creds to modify
202 *
203 *
204 * Security hooks for inode operations.
205 *
206 * @inode_alloc_security:
207 * Allocate and attach a security structure to @inode->i_security. The
208 * i_security field is initialized to NULL when the inode structure is
209 * allocated.
210 * @inode contains the inode structure.
211 * Return 0 if operation was successful.
212 * @inode_free_security:
213 * @inode contains the inode structure.
214 * Deallocate the inode security structure and set @inode->i_security to
215 * NULL.
216 * @inode_init_security:
217 * Obtain the security attribute name suffix and value to set on a newly
218 * created inode and set up the incore security field for the new inode.
219 * This hook is called by the fs code as part of the inode creation
220 * transaction and provides for atomic labeling of the inode, unlike
221 * the post_create/mkdir/... hooks called by the VFS. The hook function
222 * is expected to allocate the name and value via kmalloc, with the caller
223 * being responsible for calling kfree after using them.
224 * If the security module does not use security attributes or does
225 * not wish to put a security attribute on this particular inode,
226 * then it should return -EOPNOTSUPP to skip this processing.
227 * @inode contains the inode structure of the newly created inode.
228 * @dir contains the inode structure of the parent directory.
229 * @qstr contains the last path component of the new object
230 * @name will be set to the allocated name suffix (e.g. selinux).
231 * @value will be set to the allocated attribute value.
232 * @len will be set to the length of the value.
233 * Returns 0 if @name and @value have been successfully set,
234 * -EOPNOTSUPP if no security attribute is needed, or
235 * -ENOMEM on memory allocation failure.
236 * @inode_create:
237 * Check permission to create a regular file.
238 * @dir contains inode structure of the parent of the new file.
239 * @dentry contains the dentry structure for the file to be created.
240 * @mode contains the file mode of the file to be created.
241 * Return 0 if permission is granted.
242 * @inode_link:
243 * Check permission before creating a new hard link to a file.
244 * @old_dentry contains the dentry structure for an existing
245 * link to the file.
246 * @dir contains the inode structure of the parent directory
247 * of the new link.
248 * @new_dentry contains the dentry structure for the new link.
249 * Return 0 if permission is granted.
250 * @path_link:
251 * Check permission before creating a new hard link to a file.
252 * @old_dentry contains the dentry structure for an existing link
253 * to the file.
254 * @new_dir contains the path structure of the parent directory of
255 * the new link.
256 * @new_dentry contains the dentry structure for the new link.
257 * Return 0 if permission is granted.
258 * @inode_unlink:
259 * Check the permission to remove a hard link to a file.
260 * @dir contains the inode structure of parent directory of the file.
261 * @dentry contains the dentry structure for file to be unlinked.
262 * Return 0 if permission is granted.
263 * @path_unlink:
264 * Check the permission to remove a hard link to a file.
265 * @dir contains the path structure of parent directory of the file.
266 * @dentry contains the dentry structure for file to be unlinked.
267 * Return 0 if permission is granted.
268 * @inode_symlink:
269 * Check the permission to create a symbolic link to a file.
270 * @dir contains the inode structure of parent directory of
271 * the symbolic link.
272 * @dentry contains the dentry structure of the symbolic link.
273 * @old_name contains the pathname of file.
274 * Return 0 if permission is granted.
275 * @path_symlink:
276 * Check the permission to create a symbolic link to a file.
277 * @dir contains the path structure of parent directory of
278 * the symbolic link.
279 * @dentry contains the dentry structure of the symbolic link.
280 * @old_name contains the pathname of file.
281 * Return 0 if permission is granted.
282 * @inode_mkdir:
283 * Check permissions to create a new directory in the existing directory
284 * associated with inode structure @dir.
285 * @dir contains the inode structure of parent of the directory
286 * to be created.
287 * @dentry contains the dentry structure of new directory.
288 * @mode contains the mode of new directory.
289 * Return 0 if permission is granted.
290 * @path_mkdir:
291 * Check permissions to create a new directory in the existing directory
292 * associated with path structure @path.
293 * @dir contains the path structure of parent of the directory
294 * to be created.
295 * @dentry contains the dentry structure of new directory.
296 * @mode contains the mode of new directory.
297 * Return 0 if permission is granted.
298 * @inode_rmdir:
299 * Check the permission to remove a directory.
300 * @dir contains the inode structure of parent of the directory
301 * to be removed.
302 * @dentry contains the dentry structure of directory to be removed.
303 * Return 0 if permission is granted.
304 * @path_rmdir:
305 * Check the permission to remove a directory.
306 * @dir contains the path structure of parent of the directory to be
307 * removed.
308 * @dentry contains the dentry structure of directory to be removed.
309 * Return 0 if permission is granted.
310 * @inode_mknod:
311 * Check permissions when creating a special file (or a socket or a fifo
312 * file created via the mknod system call). Note that if mknod operation
313 * is being done for a regular file, then the create hook will be called
314 * and not this hook.
315 * @dir contains the inode structure of parent of the new file.
316 * @dentry contains the dentry structure of the new file.
317 * @mode contains the mode of the new file.
318 * @dev contains the device number.
319 * Return 0 if permission is granted.
320 * @path_mknod:
321 * Check permissions when creating a file. Note that this hook is called
322 * even if mknod operation is being done for a regular file.
323 * @dir contains the path structure of parent of the new file.
324 * @dentry contains the dentry structure of the new file.
325 * @mode contains the mode of the new file.
326 * @dev contains the undecoded device number. Use new_decode_dev() to get
327 * the decoded device number.
328 * Return 0 if permission is granted.
329 * @inode_rename:
330 * Check for permission to rename a file or directory.
331 * @old_dir contains the inode structure for parent of the old link.
332 * @old_dentry contains the dentry structure of the old link.
333 * @new_dir contains the inode structure for parent of the new link.
334 * @new_dentry contains the dentry structure of the new link.
335 * Return 0 if permission is granted.
336 * @path_rename:
337 * Check for permission to rename a file or directory.
338 * @old_dir contains the path structure for parent of the old link.
339 * @old_dentry contains the dentry structure of the old link.
340 * @new_dir contains the path structure for parent of the new link.
341 * @new_dentry contains the dentry structure of the new link.
342 * Return 0 if permission is granted.
343 * @path_chmod:
344 * Check for permission to change a mode of the file @path. The new
345 * mode is specified in @mode.
346 * @path contains the path structure of the file to change the mode.
347 * @mode contains the new DAC's permission, which is a bitmask of
348 * constants from <include/uapi/linux/stat.h>
349 * Return 0 if permission is granted.
350 * @path_chown:
351 * Check for permission to change owner/group of a file or directory.
352 * @path contains the path structure.
353 * @uid contains new owner's ID.
354 * @gid contains new group's ID.
355 * Return 0 if permission is granted.
356 * @path_chroot:
357 * Check for permission to change root directory.
358 * @path contains the path structure.
359 * Return 0 if permission is granted.
360 * @path_notify:
361 * Check permissions before setting a watch on events as defined by @mask,
362 * on an object at @path, whose type is defined by @obj_type.
363 * @inode_readlink:
364 * Check the permission to read the symbolic link.
365 * @dentry contains the dentry structure for the file link.
366 * Return 0 if permission is granted.
367 * @inode_follow_link:
368 * Check permission to follow a symbolic link when looking up a pathname.
369 * @dentry contains the dentry structure for the link.
370 * @inode contains the inode, which itself is not stable in RCU-walk
371 * @rcu indicates whether we are in RCU-walk mode.
372 * Return 0 if permission is granted.
373 * @inode_permission:
374 * Check permission before accessing an inode. This hook is called by the
375 * existing Linux permission function, so a security module can use it to
376 * provide additional checking for existing Linux permission checks.
377 * Notice that this hook is called when a file is opened (as well as many
378 * other operations), whereas the file_security_ops permission hook is
379 * called when the actual read/write operations are performed.
380 * @inode contains the inode structure to check.
381 * @mask contains the permission mask.
382 * Return 0 if permission is granted.
383 * @inode_setattr:
384 * Check permission before setting file attributes. Note that the kernel
385 * call to notify_change is performed from several locations, whenever
386 * file attributes change (such as when a file is truncated, chown/chmod
387 * operations, transferring disk quotas, etc).
388 * @dentry contains the dentry structure for the file.
389 * @attr is the iattr structure containing the new file attributes.
390 * Return 0 if permission is granted.
391 * @path_truncate:
392 * Check permission before truncating a file.
393 * @path contains the path structure for the file.
394 * Return 0 if permission is granted.
395 * @inode_getattr:
396 * Check permission before obtaining file attributes.
397 * @path contains the path structure for the file.
398 * Return 0 if permission is granted.
399 * @inode_setxattr:
400 * Check permission before setting the extended attributes
401 * @value identified by @name for @dentry.
402 * Return 0 if permission is granted.
403 * @inode_post_setxattr:
404 * Update inode security field after successful setxattr operation.
405 * @value identified by @name for @dentry.
406 * @inode_getxattr:
407 * Check permission before obtaining the extended attributes
408 * identified by @name for @dentry.
409 * Return 0 if permission is granted.
410 * @inode_listxattr:
411 * Check permission before obtaining the list of extended attribute
412 * names for @dentry.
413 * Return 0 if permission is granted.
414 * @inode_removexattr:
415 * Check permission before removing the extended attribute
416 * identified by @name for @dentry.
417 * Return 0 if permission is granted.
418 * @inode_getsecurity:
419 * Retrieve a copy of the extended attribute representation of the
420 * security label associated with @name for @inode via @buffer. Note that
421 * @name is the remainder of the attribute name after the security prefix
422 * has been removed. @alloc is used to specify of the call should return a
423 * value via the buffer or just the value length Return size of buffer on
424 * success.
425 * @inode_setsecurity:
426 * Set the security label associated with @name for @inode from the
427 * extended attribute value @value. @size indicates the size of the
428 * @value in bytes. @flags may be XATTR_CREATE, XATTR_REPLACE, or 0.
429 * Note that @name is the remainder of the attribute name after the
430 * security. prefix has been removed.
431 * Return 0 on success.
432 * @inode_listsecurity:
433 * Copy the extended attribute names for the security labels
434 * associated with @inode into @buffer. The maximum size of @buffer
435 * is specified by @buffer_size. @buffer may be NULL to request
436 * the size of the buffer required.
437 * Returns number of bytes used/required on success.
438 * @inode_need_killpriv:
439 * Called when an inode has been changed.
440 * @dentry is the dentry being changed.
441 * Return <0 on error to abort the inode change operation.
442 * Return 0 if inode_killpriv does not need to be called.
443 * Return >0 if inode_killpriv does need to be called.
444 * @inode_killpriv:
445 * The setuid bit is being removed. Remove similar security labels.
446 * Called with the dentry->d_inode->i_mutex held.
447 * @dentry is the dentry being changed.
448 * Return 0 on success. If error is returned, then the operation
449 * causing setuid bit removal is failed.
450 * @inode_getsecid:
451 * Get the secid associated with the node.
452 * @inode contains a pointer to the inode.
453 * @secid contains a pointer to the location where result will be saved.
454 * In case of failure, @secid will be set to zero.
455 * @inode_copy_up:
456 * A file is about to be copied up from lower layer to upper layer of
457 * overlay filesystem. Security module can prepare a set of new creds
458 * and modify as need be and return new creds. Caller will switch to
459 * new creds temporarily to create new file and release newly allocated
460 * creds.
461 * @src indicates the union dentry of file that is being copied up.
462 * @new pointer to pointer to return newly allocated creds.
463 * Returns 0 on success or a negative error code on error.
464 * @inode_copy_up_xattr:
465 * Filter the xattrs being copied up when a unioned file is copied
466 * up from a lower layer to the union/overlay layer.
467 * @name indicates the name of the xattr.
468 * Returns 0 to accept the xattr, 1 to discard the xattr, -EOPNOTSUPP if
469 * security module does not know about attribute or a negative error code
470 * to abort the copy up. Note that the caller is responsible for reading
471 * and writing the xattrs as this hook is merely a filter.
472 * @d_instantiate:
473 * Fill in @inode security information for a @dentry if allowed.
474 * @getprocattr:
475 * Read attribute @name for process @p and store it into @value if allowed.
476 * @setprocattr:
477 * Write (set) attribute @name to @value, size @size if allowed.
478 *
479 * Security hooks for kernfs node operations
480 *
481 * @kernfs_init_security:
482 * Initialize the security context of a newly created kernfs node based
483 * on its own and its parent's attributes.
484 *
485 * @kn_dir the parent kernfs node
486 * @kn the new child kernfs node
487 *
488 * Security hooks for file operations
489 *
490 * @file_permission:
491 * Check file permissions before accessing an open file. This hook is
492 * called by various operations that read or write files. A security
493 * module can use this hook to perform additional checking on these
494 * operations, e.g. to revalidate permissions on use to support privilege
495 * bracketing or policy changes. Notice that this hook is used when the
496 * actual read/write operations are performed, whereas the
497 * inode_security_ops hook is called when a file is opened (as well as
498 * many other operations).
499 * Caveat: Although this hook can be used to revalidate permissions for
500 * various system call operations that read or write files, it does not
501 * address the revalidation of permissions for memory-mapped files.
502 * Security modules must handle this separately if they need such
503 * revalidation.
504 * @file contains the file structure being accessed.
505 * @mask contains the requested permissions.
506 * Return 0 if permission is granted.
507 * @file_alloc_security:
508 * Allocate and attach a security structure to the file->f_security field.
509 * The security field is initialized to NULL when the structure is first
510 * created.
511 * @file contains the file structure to secure.
512 * Return 0 if the hook is successful and permission is granted.
513 * @file_free_security:
514 * Deallocate and free any security structures stored in file->f_security.
515 * @file contains the file structure being modified.
516 * @file_ioctl:
517 * @file contains the file structure.
518 * @cmd contains the operation to perform.
519 * @arg contains the operational arguments.
520 * Check permission for an ioctl operation on @file. Note that @arg
521 * sometimes represents a user space pointer; in other cases, it may be a
522 * simple integer value. When @arg represents a user space pointer, it
523 * should never be used by the security module.
524 * Return 0 if permission is granted.
525 * @mmap_addr :
526 * Check permissions for a mmap operation at @addr.
527 * @addr contains virtual address that will be used for the operation.
528 * Return 0 if permission is granted.
529 * @mmap_file :
530 * Check permissions for a mmap operation. The @file may be NULL, e.g.
531 * if mapping anonymous memory.
532 * @file contains the file structure for file to map (may be NULL).
533 * @reqprot contains the protection requested by the application.
534 * @prot contains the protection that will be applied by the kernel.
535 * @flags contains the operational flags.
536 * Return 0 if permission is granted.
537 * @mmap_region :
538 * Check permission for a mmap operation. The @file may be NULL, e,g.
539 * if mapping anonymous memory.
540 * @vma contains the memory region to mmap.
541 * @file_mprotect:
542 * Check permissions before changing memory access permissions.
543 * @vma contains the memory region to modify.
544 * @reqprot contains the protection requested by the application.
545 * @prot contains the protection that will be applied by the kernel.
546 * Return 0 if permission is granted.
547 * @file_lock:
548 * Check permission before performing file locking operations.
549 * Note the hook mediates both flock and fcntl style locks.
550 * @file contains the file structure.
551 * @cmd contains the posix-translated lock operation to perform
552 * (e.g. F_RDLCK, F_WRLCK).
553 * Return 0 if permission is granted.
554 * @file_fcntl:
555 * Check permission before allowing the file operation specified by @cmd
556 * from being performed on the file @file. Note that @arg sometimes
557 * represents a user space pointer; in other cases, it may be a simple
558 * integer value. When @arg represents a user space pointer, it should
559 * never be used by the security module.
560 * @file contains the file structure.
561 * @cmd contains the operation to be performed.
562 * @arg contains the operational arguments.
563 * Return 0 if permission is granted.
564 * @file_set_fowner:
565 * Save owner security information (typically from current->security) in
566 * file->f_security for later use by the send_sigiotask hook.
567 * @file contains the file structure to update.
568 * Return 0 on success.
569 * @file_send_sigiotask:
570 * Check permission for the file owner @fown to send SIGIO or SIGURG to the
571 * process @tsk. Note that this hook is sometimes called from interrupt.
572 * Note that the fown_struct, @fown, is never outside the context of a
573 * struct file, so the file structure (and associated security information)
574 * can always be obtained: container_of(fown, struct file, f_owner)
575 * @tsk contains the structure of task receiving signal.
576 * @fown contains the file owner information.
577 * @sig is the signal that will be sent. When 0, kernel sends SIGIO.
578 * Return 0 if permission is granted.
579 * @file_receive:
580 * This hook allows security modules to control the ability of a process
581 * to receive an open file descriptor via socket IPC.
582 * @file contains the file structure being received.
583 * Return 0 if permission is granted.
584 * @file_open:
585 * Save open-time permission checking state for later use upon
586 * file_permission, and recheck access if anything has changed
587 * since inode_permission.
588 *
589 * Security hooks for task operations.
590 *
591 * @task_alloc:
592 * @task task being allocated.
593 * @clone_flags contains the flags indicating what should be shared.
594 * Handle allocation of task-related resources.
595 * Returns a zero on success, negative values on failure.
596 * @task_free:
597 * @task task about to be freed.
598 * Handle release of task-related resources. (Note that this can be called
599 * from interrupt context.)
600 * @cred_alloc_blank:
601 * @cred points to the credentials.
602 * @gfp indicates the atomicity of any memory allocations.
603 * Only allocate sufficient memory and attach to @cred such that
604 * cred_transfer() will not get ENOMEM.
605 * @cred_free:
606 * @cred points to the credentials.
607 * Deallocate and clear the cred->security field in a set of credentials.
608 * @cred_prepare:
609 * @new points to the new credentials.
610 * @old points to the original credentials.
611 * @gfp indicates the atomicity of any memory allocations.
612 * Prepare a new set of credentials by copying the data from the old set.
613 * @cred_transfer:
614 * @new points to the new credentials.
615 * @old points to the original credentials.
616 * Transfer data from original creds to new creds
617 * @cred_getsecid:
618 * Retrieve the security identifier of the cred structure @c
619 * @c contains the credentials, secid will be placed into @secid.
620 * In case of failure, @secid will be set to zero.
621 * @kernel_act_as:
622 * Set the credentials for a kernel service to act as (subjective context).
623 * @new points to the credentials to be modified.
624 * @secid specifies the security ID to be set
625 * The current task must be the one that nominated @secid.
626 * Return 0 if successful.
627 * @kernel_create_files_as:
628 * Set the file creation context in a set of credentials to be the same as
629 * the objective context of the specified inode.
630 * @new points to the credentials to be modified.
631 * @inode points to the inode to use as a reference.
632 * The current task must be the one that nominated @inode.
633 * Return 0 if successful.
634 * @kernel_module_request:
635 * Ability to trigger the kernel to automatically upcall to userspace for
636 * userspace to load a kernel module with the given name.
637 * @kmod_name name of the module requested by the kernel
638 * Return 0 if successful.
639 * @kernel_load_data:
640 * Load data provided by userspace.
641 * @id kernel load data identifier
642 * @contents if a subsequent @kernel_post_load_data will be called.
643 * Return 0 if permission is granted.
644 * @kernel_post_load_data:
645 * Load data provided by a non-file source (usually userspace buffer).
646 * @buf pointer to buffer containing the data contents.
647 * @size length of the data contents.
648 * @id kernel load data identifier
649 * @description a text description of what was loaded, @id-specific
650 * Return 0 if permission is granted.
651 * This must be paired with a prior @kernel_load_data call that had
652 * @contents set to true.
653 * @kernel_read_file:
654 * Read a file specified by userspace.
655 * @file contains the file structure pointing to the file being read
656 * by the kernel.
657 * @id kernel read file identifier
658 * @contents if a subsequent @kernel_post_read_file will be called.
659 * Return 0 if permission is granted.
660 * @kernel_post_read_file:
661 * Read a file specified by userspace.
662 * @file contains the file structure pointing to the file being read
663 * by the kernel.
664 * @buf pointer to buffer containing the file contents.
665 * @size length of the file contents.
666 * @id kernel read file identifier
667 * This must be paired with a prior @kernel_read_file call that had
668 * @contents set to true.
669 * Return 0 if permission is granted.
670 * @task_fix_setuid:
671 * Update the module's state after setting one or more of the user
672 * identity attributes of the current process. The @flags parameter
673 * indicates which of the set*uid system calls invoked this hook. If
674 * @new is the set of credentials that will be installed. Modifications
675 * should be made to this rather than to @current->cred.
676 * @old is the set of credentials that are being replaces
677 * @flags contains one of the LSM_SETID_* values.
678 * Return 0 on success.
679 * @task_fix_setgid:
680 * Update the module's state after setting one or more of the group
681 * identity attributes of the current process. The @flags parameter
682 * indicates which of the set*gid system calls invoked this hook.
683 * @new is the set of credentials that will be installed. Modifications
684 * should be made to this rather than to @current->cred.
685 * @old is the set of credentials that are being replaced.
686 * @flags contains one of the LSM_SETID_* values.
687 * Return 0 on success.
688 * @task_setpgid:
689 * Check permission before setting the process group identifier of the
690 * process @p to @pgid.
691 * @p contains the task_struct for process being modified.
692 * @pgid contains the new pgid.
693 * Return 0 if permission is granted.
694 * @task_getpgid:
695 * Check permission before getting the process group identifier of the
696 * process @p.
697 * @p contains the task_struct for the process.
698 * Return 0 if permission is granted.
699 * @task_getsid:
700 * Check permission before getting the session identifier of the process
701 * @p.
702 * @p contains the task_struct for the process.
703 * Return 0 if permission is granted.
704 * @task_getsecid:
705 * Retrieve the security identifier of the process @p.
706 * @p contains the task_struct for the process and place is into @secid.
707 * In case of failure, @secid will be set to zero.
708 *
709 * @task_setnice:
710 * Check permission before setting the nice value of @p to @nice.
711 * @p contains the task_struct of process.
712 * @nice contains the new nice value.
713 * Return 0 if permission is granted.
714 * @task_setioprio:
715 * Check permission before setting the ioprio value of @p to @ioprio.
716 * @p contains the task_struct of process.
717 * @ioprio contains the new ioprio value
718 * Return 0 if permission is granted.
719 * @task_getioprio:
720 * Check permission before getting the ioprio value of @p.
721 * @p contains the task_struct of process.
722 * Return 0 if permission is granted.
723 * @task_prlimit:
724 * Check permission before getting and/or setting the resource limits of
725 * another task.
726 * @cred points to the cred structure for the current task.
727 * @tcred points to the cred structure for the target task.
728 * @flags contains the LSM_PRLIMIT_* flag bits indicating whether the
729 * resource limits are being read, modified, or both.
730 * Return 0 if permission is granted.
731 * @task_setrlimit:
732 * Check permission before setting the resource limits of process @p
733 * for @resource to @new_rlim. The old resource limit values can
734 * be examined by dereferencing (p->signal->rlim + resource).
735 * @p points to the task_struct for the target task's group leader.
736 * @resource contains the resource whose limit is being set.
737 * @new_rlim contains the new limits for @resource.
738 * Return 0 if permission is granted.
739 * @task_setscheduler:
740 * Check permission before setting scheduling policy and/or parameters of
741 * process @p.
742 * @p contains the task_struct for process.
743 * Return 0 if permission is granted.
744 * @task_getscheduler:
745 * Check permission before obtaining scheduling information for process
746 * @p.
747 * @p contains the task_struct for process.
748 * Return 0 if permission is granted.
749 * @task_movememory:
750 * Check permission before moving memory owned by process @p.
751 * @p contains the task_struct for process.
752 * Return 0 if permission is granted.
753 * @task_kill:
754 * Check permission before sending signal @sig to @p. @info can be NULL,
755 * the constant 1, or a pointer to a kernel_siginfo structure. If @info is 1 or
756 * SI_FROMKERNEL(info) is true, then the signal should be viewed as coming
757 * from the kernel and should typically be permitted.
758 * SIGIO signals are handled separately by the send_sigiotask hook in
759 * file_security_ops.
760 * @p contains the task_struct for process.
761 * @info contains the signal information.
762 * @sig contains the signal value.
763 * @cred contains the cred of the process where the signal originated, or
764 * NULL if the current task is the originator.
765 * Return 0 if permission is granted.
766 * @task_prctl:
767 * Check permission before performing a process control operation on the
768 * current process.
769 * @option contains the operation.
770 * @arg2 contains a argument.
771 * @arg3 contains a argument.
772 * @arg4 contains a argument.
773 * @arg5 contains a argument.
774 * Return -ENOSYS if no-one wanted to handle this op, any other value to
775 * cause prctl() to return immediately with that value.
776 * @task_to_inode:
777 * Set the security attributes for an inode based on an associated task's
778 * security attributes, e.g. for /proc/pid inodes.
779 * @p contains the task_struct for the task.
780 * @inode contains the inode structure for the inode.
781 *
782 * Security hooks for Netlink messaging.
783 *
784 * @netlink_send:
785 * Save security information for a netlink message so that permission
786 * checking can be performed when the message is processed. The security
787 * information can be saved using the eff_cap field of the
788 * netlink_skb_parms structure. Also may be used to provide fine
789 * grained control over message transmission.
790 * @sk associated sock of task sending the message.
791 * @skb contains the sk_buff structure for the netlink message.
792 * Return 0 if the information was successfully saved and message
793 * is allowed to be transmitted.
794 *
795 * Security hooks for Unix domain networking.
796 *
797 * @unix_stream_connect:
798 * Check permissions before establishing a Unix domain stream connection
799 * between @sock and @other.
800 * @sock contains the sock structure.
801 * @other contains the peer sock structure.
802 * @newsk contains the new sock structure.
803 * Return 0 if permission is granted.
804 * @unix_may_send:
805 * Check permissions before connecting or sending datagrams from @sock to
806 * @other.
807 * @sock contains the socket structure.
808 * @other contains the peer socket structure.
809 * Return 0 if permission is granted.
810 *
811 * The @unix_stream_connect and @unix_may_send hooks were necessary because
812 * Linux provides an alternative to the conventional file name space for Unix
813 * domain sockets. Whereas binding and connecting to sockets in the file name
814 * space is mediated by the typical file permissions (and caught by the mknod
815 * and permission hooks in inode_security_ops), binding and connecting to
816 * sockets in the abstract name space is completely unmediated. Sufficient
817 * control of Unix domain sockets in the abstract name space isn't possible
818 * using only the socket layer hooks, since we need to know the actual target
819 * socket, which is not looked up until we are inside the af_unix code.
820 *
821 * Security hooks for socket operations.
822 *
823 * @socket_create:
824 * Check permissions prior to creating a new socket.
825 * @family contains the requested protocol family.
826 * @type contains the requested communications type.
827 * @protocol contains the requested protocol.
828 * @kern set to 1 if a kernel socket.
829 * Return 0 if permission is granted.
830 * @socket_post_create:
831 * This hook allows a module to update or allocate a per-socket security
832 * structure. Note that the security field was not added directly to the
833 * socket structure, but rather, the socket security information is stored
834 * in the associated inode. Typically, the inode alloc_security hook will
835 * allocate and attach security information to
836 * SOCK_INODE(sock)->i_security. This hook may be used to update the
837 * SOCK_INODE(sock)->i_security field with additional information that
838 * wasn't available when the inode was allocated.
839 * @sock contains the newly created socket structure.
840 * @family contains the requested protocol family.
841 * @type contains the requested communications type.
842 * @protocol contains the requested protocol.
843 * @kern set to 1 if a kernel socket.
844 * @socket_socketpair:
845 * Check permissions before creating a fresh pair of sockets.
846 * @socka contains the first socket structure.
847 * @sockb contains the second socket structure.
848 * Return 0 if permission is granted and the connection was established.
849 * @socket_bind:
850 * Check permission before socket protocol layer bind operation is
851 * performed and the socket @sock is bound to the address specified in the
852 * @address parameter.
853 * @sock contains the socket structure.
854 * @address contains the address to bind to.
855 * @addrlen contains the length of address.
856 * Return 0 if permission is granted.
857 * @socket_connect:
858 * Check permission before socket protocol layer connect operation
859 * attempts to connect socket @sock to a remote address, @address.
860 * @sock contains the socket structure.
861 * @address contains the address of remote endpoint.
862 * @addrlen contains the length of address.
863 * Return 0 if permission is granted.
864 * @socket_listen:
865 * Check permission before socket protocol layer listen operation.
866 * @sock contains the socket structure.
867 * @backlog contains the maximum length for the pending connection queue.
868 * Return 0 if permission is granted.
869 * @socket_accept:
870 * Check permission before accepting a new connection. Note that the new
871 * socket, @newsock, has been created and some information copied to it,
872 * but the accept operation has not actually been performed.
873 * @sock contains the listening socket structure.
874 * @newsock contains the newly created server socket for connection.
875 * Return 0 if permission is granted.
876 * @socket_sendmsg:
877 * Check permission before transmitting a message to another socket.
878 * @sock contains the socket structure.
879 * @msg contains the message to be transmitted.
880 * @size contains the size of message.
881 * Return 0 if permission is granted.
882 * @socket_recvmsg:
883 * Check permission before receiving a message from a socket.
884 * @sock contains the socket structure.
885 * @msg contains the message structure.
886 * @size contains the size of message structure.
887 * @flags contains the operational flags.
888 * Return 0 if permission is granted.
889 * @socket_getsockname:
890 * Check permission before the local address (name) of the socket object
891 * @sock is retrieved.
892 * @sock contains the socket structure.
893 * Return 0 if permission is granted.
894 * @socket_getpeername:
895 * Check permission before the remote address (name) of a socket object
896 * @sock is retrieved.
897 * @sock contains the socket structure.
898 * Return 0 if permission is granted.
899 * @socket_getsockopt:
900 * Check permissions before retrieving the options associated with socket
901 * @sock.
902 * @sock contains the socket structure.
903 * @level contains the protocol level to retrieve option from.
904 * @optname contains the name of option to retrieve.
905 * Return 0 if permission is granted.
906 * @socket_setsockopt:
907 * Check permissions before setting the options associated with socket
908 * @sock.
909 * @sock contains the socket structure.
910 * @level contains the protocol level to set options for.
911 * @optname contains the name of the option to set.
912 * Return 0 if permission is granted.
913 * @socket_shutdown:
914 * Checks permission before all or part of a connection on the socket
915 * @sock is shut down.
916 * @sock contains the socket structure.
917 * @how contains the flag indicating how future sends and receives
918 * are handled.
919 * Return 0 if permission is granted.
920 * @socket_sock_rcv_skb:
921 * Check permissions on incoming network packets. This hook is distinct
922 * from Netfilter's IP input hooks since it is the first time that the
923 * incoming sk_buff @skb has been associated with a particular socket, @sk.
924 * Must not sleep inside this hook because some callers hold spinlocks.
925 * @sk contains the sock (not socket) associated with the incoming sk_buff.
926 * @skb contains the incoming network data.
927 * @socket_getpeersec_stream:
928 * This hook allows the security module to provide peer socket security
929 * state for unix or connected tcp sockets to userspace via getsockopt
930 * SO_GETPEERSEC. For tcp sockets this can be meaningful if the
931 * socket is associated with an ipsec SA.
932 * @sock is the local socket.
933 * @optval userspace memory where the security state is to be copied.
934 * @optlen userspace int where the module should copy the actual length
935 * of the security state.
936 * @len as input is the maximum length to copy to userspace provided
937 * by the caller.
938 * Return 0 if all is well, otherwise, typical getsockopt return
939 * values.
940 * @socket_getpeersec_dgram:
941 * This hook allows the security module to provide peer socket security
942 * state for udp sockets on a per-packet basis to userspace via
943 * getsockopt SO_GETPEERSEC. The application must first have indicated
944 * the IP_PASSSEC option via getsockopt. It can then retrieve the
945 * security state returned by this hook for a packet via the SCM_SECURITY
946 * ancillary message type.
947 * @sock contains the peer socket. May be NULL.
948 * @skb is the sk_buff for the packet being queried. May be NULL.
949 * @secid pointer to store the secid of the packet.
950 * Return 0 on success, error on failure.
951 * @sk_alloc_security:
952 * Allocate and attach a security structure to the sk->sk_security field,
953 * which is used to copy security attributes between local stream sockets.
954 * @sk_free_security:
955 * Deallocate security structure.
956 * @sk_clone_security:
957 * Clone/copy security structure.
958 * @sk_getsecid:
959 * Retrieve the LSM-specific secid for the sock to enable caching
960 * of network authorizations.
961 * @sock_graft:
962 * Sets the socket's isec sid to the sock's sid.
963 * @inet_conn_request:
964 * Sets the openreq's sid to socket's sid with MLS portion taken
965 * from peer sid.
966 * @inet_csk_clone:
967 * Sets the new child socket's sid to the openreq sid.
968 * @inet_conn_established:
969 * Sets the connection's peersid to the secmark on skb.
970 * @secmark_relabel_packet:
971 * check if the process should be allowed to relabel packets to
972 * the given secid
973 * @secmark_refcount_inc:
974 * tells the LSM to increment the number of secmark labeling rules loaded
975 * @secmark_refcount_dec:
976 * tells the LSM to decrement the number of secmark labeling rules loaded
977 * @req_classify_flow:
978 * Sets the flow's sid to the openreq sid.
979 * @tun_dev_alloc_security:
980 * This hook allows a module to allocate a security structure for a TUN
981 * device.
982 * @security pointer to a security structure pointer.
983 * Returns a zero on success, negative values on failure.
984 * @tun_dev_free_security:
985 * This hook allows a module to free the security structure for a TUN
986 * device.
987 * @security pointer to the TUN device's security structure
988 * @tun_dev_create:
989 * Check permissions prior to creating a new TUN device.
990 * @tun_dev_attach_queue:
991 * Check permissions prior to attaching to a TUN device queue.
992 * @security pointer to the TUN device's security structure.
993 * @tun_dev_attach:
994 * This hook can be used by the module to update any security state
995 * associated with the TUN device's sock structure.
996 * @sk contains the existing sock structure.
997 * @security pointer to the TUN device's security structure.
998 * @tun_dev_open:
999 * This hook can be used by the module to update any security state
1000 * associated with the TUN device's security structure.
1001 * @security pointer to the TUN devices's security structure.
1002 *
1003 * Security hooks for SCTP
1004 *
1005 * @sctp_assoc_request:
1006 * Passes the @ep and @chunk->skb of the association INIT packet to
1007 * the security module.
1008 * @ep pointer to sctp endpoint structure.
1009 * @skb pointer to skbuff of association packet.
1010 * Return 0 on success, error on failure.
1011 * @sctp_bind_connect:
1012 * Validiate permissions required for each address associated with sock
1013 * @sk. Depending on @optname, the addresses will be treated as either
1014 * for a connect or bind service. The @addrlen is calculated on each
1015 * ipv4 and ipv6 address using sizeof(struct sockaddr_in) or
1016 * sizeof(struct sockaddr_in6).
1017 * @sk pointer to sock structure.
1018 * @optname name of the option to validate.
1019 * @address list containing one or more ipv4/ipv6 addresses.
1020 * @addrlen total length of address(s).
1021 * Return 0 on success, error on failure.
1022 * @sctp_sk_clone:
1023 * Called whenever a new socket is created by accept(2) (i.e. a TCP
1024 * style socket) or when a socket is 'peeled off' e.g userspace
1025 * calls sctp_peeloff(3).
1026 * @ep pointer to current sctp endpoint structure.
1027 * @sk pointer to current sock structure.
1028 * @sk pointer to new sock structure.
1029 *
1030 * Security hooks for Infiniband
1031 *
1032 * @ib_pkey_access:
1033 * Check permission to access a pkey when modifing a QP.
1034 * @subnet_prefix the subnet prefix of the port being used.
1035 * @pkey the pkey to be accessed.
1036 * @sec pointer to a security structure.
1037 * @ib_endport_manage_subnet:
1038 * Check permissions to send and receive SMPs on a end port.
1039 * @dev_name the IB device name (i.e. mlx4_0).
1040 * @port_num the port number.
1041 * @sec pointer to a security structure.
1042 * @ib_alloc_security:
1043 * Allocate a security structure for Infiniband objects.
1044 * @sec pointer to a security structure pointer.
1045 * Returns 0 on success, non-zero on failure
1046 * @ib_free_security:
1047 * Deallocate an Infiniband security structure.
1048 * @sec contains the security structure to be freed.
1049 *
1050 * Security hooks for XFRM operations.
1051 *
1052 * @xfrm_policy_alloc_security:
1053 * @ctxp is a pointer to the xfrm_sec_ctx being added to Security Policy
1054 * Database used by the XFRM system.
1055 * @sec_ctx contains the security context information being provided by
1056 * the user-level policy update program (e.g., setkey).
1057 * Allocate a security structure to the xp->security field; the security
1058 * field is initialized to NULL when the xfrm_policy is allocated.
1059 * Return 0 if operation was successful (memory to allocate, legal context)
1060 * @gfp is to specify the context for the allocation
1061 * @xfrm_policy_clone_security:
1062 * @old_ctx contains an existing xfrm_sec_ctx.
1063 * @new_ctxp contains a new xfrm_sec_ctx being cloned from old.
1064 * Allocate a security structure in new_ctxp that contains the
1065 * information from the old_ctx structure.
1066 * Return 0 if operation was successful (memory to allocate).
1067 * @xfrm_policy_free_security:
1068 * @ctx contains the xfrm_sec_ctx
1069 * Deallocate xp->security.
1070 * @xfrm_policy_delete_security:
1071 * @ctx contains the xfrm_sec_ctx.
1072 * Authorize deletion of xp->security.
1073 * @xfrm_state_alloc:
1074 * @x contains the xfrm_state being added to the Security Association
1075 * Database by the XFRM system.
1076 * @sec_ctx contains the security context information being provided by
1077 * the user-level SA generation program (e.g., setkey or racoon).
1078 * Allocate a security structure to the x->security field; the security
1079 * field is initialized to NULL when the xfrm_state is allocated. Set the
1080 * context to correspond to sec_ctx. Return 0 if operation was successful
1081 * (memory to allocate, legal context).
1082 * @xfrm_state_alloc_acquire:
1083 * @x contains the xfrm_state being added to the Security Association
1084 * Database by the XFRM system.
1085 * @polsec contains the policy's security context.
1086 * @secid contains the secid from which to take the mls portion of the
1087 * context.
1088 * Allocate a security structure to the x->security field; the security
1089 * field is initialized to NULL when the xfrm_state is allocated. Set the
1090 * context to correspond to secid. Return 0 if operation was successful
1091 * (memory to allocate, legal context).
1092 * @xfrm_state_free_security:
1093 * @x contains the xfrm_state.
1094 * Deallocate x->security.
1095 * @xfrm_state_delete_security:
1096 * @x contains the xfrm_state.
1097 * Authorize deletion of x->security.
1098 * @xfrm_policy_lookup:
1099 * @ctx contains the xfrm_sec_ctx for which the access control is being
1100 * checked.
1101 * @fl_secid contains the flow security label that is used to authorize
1102 * access to the policy xp.
1103 * @dir contains the direction of the flow (input or output).
1104 * Check permission when a flow selects a xfrm_policy for processing
1105 * XFRMs on a packet. The hook is called when selecting either a
1106 * per-socket policy or a generic xfrm policy.
1107 * Return 0 if permission is granted, -ESRCH otherwise, or -errno
1108 * on other errors.
1109 * @xfrm_state_pol_flow_match:
1110 * @x contains the state to match.
1111 * @xp contains the policy to check for a match.
1112 * @flic contains the flowi_common struct to check for a match.
1113 * Return 1 if there is a match.
1114 * @xfrm_decode_session:
1115 * @skb points to skb to decode.
1116 * @secid points to the flow key secid to set.
1117 * @ckall says if all xfrms used should be checked for same secid.
1118 * Return 0 if ckall is zero or all xfrms used have the same secid.
1119 *
1120 * Security hooks affecting all Key Management operations
1121 *
1122 * @key_alloc:
1123 * Permit allocation of a key and assign security data. Note that key does
1124 * not have a serial number assigned at this point.
1125 * @key points to the key.
1126 * @flags is the allocation flags
1127 * Return 0 if permission is granted, -ve error otherwise.
1128 * @key_free:
1129 * Notification of destruction; free security data.
1130 * @key points to the key.
1131 * No return value.
1132 * @key_permission:
1133 * See whether a specific operational right is granted to a process on a
1134 * key.
1135 * @key_ref refers to the key (key pointer + possession attribute bit).
1136 * @cred points to the credentials to provide the context against which to
1137 * evaluate the security data on the key.
1138 * @perm describes the combination of permissions required of this key.
1139 * Return 0 if permission is granted, -ve error otherwise.
1140 * @key_getsecurity:
1141 * Get a textual representation of the security context attached to a key
1142 * for the purposes of honouring KEYCTL_GETSECURITY. This function
1143 * allocates the storage for the NUL-terminated string and the caller
1144 * should free it.
1145 * @key points to the key to be queried.
1146 * @_buffer points to a pointer that should be set to point to the
1147 * resulting string (if no label or an error occurs).
1148 * Return the length of the string (including terminating NUL) or -ve if
1149 * an error.
1150 * May also return 0 (and a NULL buffer pointer) if there is no label.
1151 *
1152 * Security hooks affecting all System V IPC operations.
1153 *
1154 * @ipc_permission:
1155 * Check permissions for access to IPC
1156 * @ipcp contains the kernel IPC permission structure
1157 * @flag contains the desired (requested) permission set
1158 * Return 0 if permission is granted.
1159 * @ipc_getsecid:
1160 * Get the secid associated with the ipc object.
1161 * @ipcp contains the kernel IPC permission structure.
1162 * @secid contains a pointer to the location where result will be saved.
1163 * In case of failure, @secid will be set to zero.
1164 *
1165 * Security hooks for individual messages held in System V IPC message queues
1166 *
1167 * @msg_msg_alloc_security:
1168 * Allocate and attach a security structure to the msg->security field.
1169 * The security field is initialized to NULL when the structure is first
1170 * created.
1171 * @msg contains the message structure to be modified.
1172 * Return 0 if operation was successful and permission is granted.
1173 * @msg_msg_free_security:
1174 * Deallocate the security structure for this message.
1175 * @msg contains the message structure to be modified.
1176 *
1177 * Security hooks for System V IPC Message Queues
1178 *
1179 * @msg_queue_alloc_security:
1180 * Allocate and attach a security structure to the
1181 * @perm->security field. The security field is initialized to
1182 * NULL when the structure is first created.
1183 * @perm contains the IPC permissions of the message queue.
1184 * Return 0 if operation was successful and permission is granted.
1185 * @msg_queue_free_security:
1186 * Deallocate security field @perm->security for the message queue.
1187 * @perm contains the IPC permissions of the message queue.
1188 * @msg_queue_associate:
1189 * Check permission when a message queue is requested through the
1190 * msgget system call. This hook is only called when returning the
1191 * message queue identifier for an existing message queue, not when a
1192 * new message queue is created.
1193 * @perm contains the IPC permissions of the message queue.
1194 * @msqflg contains the operation control flags.
1195 * Return 0 if permission is granted.
1196 * @msg_queue_msgctl:
1197 * Check permission when a message control operation specified by @cmd
1198 * is to be performed on the message queue with permissions @perm.
1199 * The @perm may be NULL, e.g. for IPC_INFO or MSG_INFO.
1200 * @perm contains the IPC permissions of the msg queue. May be NULL.
1201 * @cmd contains the operation to be performed.
1202 * Return 0 if permission is granted.
1203 * @msg_queue_msgsnd:
1204 * Check permission before a message, @msg, is enqueued on the message
1205 * queue with permissions @perm.
1206 * @perm contains the IPC permissions of the message queue.
1207 * @msg contains the message to be enqueued.
1208 * @msqflg contains operational flags.
1209 * Return 0 if permission is granted.
1210 * @msg_queue_msgrcv:
1211 * Check permission before a message, @msg, is removed from the message
1212 * queue. The @target task structure contains a pointer to the
1213 * process that will be receiving the message (not equal to the current
1214 * process when inline receives are being performed).
1215 * @perm contains the IPC permissions of the message queue.
1216 * @msg contains the message destination.
1217 * @target contains the task structure for recipient process.
1218 * @type contains the type of message requested.
1219 * @mode contains the operational flags.
1220 * Return 0 if permission is granted.
1221 *
1222 * Security hooks for System V Shared Memory Segments
1223 *
1224 * @shm_alloc_security:
1225 * Allocate and attach a security structure to the @perm->security
1226 * field. The security field is initialized to NULL when the structure is
1227 * first created.
1228 * @perm contains the IPC permissions of the shared memory structure.
1229 * Return 0 if operation was successful and permission is granted.
1230 * @shm_free_security:
1231 * Deallocate the security structure @perm->security for the memory segment.
1232 * @perm contains the IPC permissions of the shared memory structure.
1233 * @shm_associate:
1234 * Check permission when a shared memory region is requested through the
1235 * shmget system call. This hook is only called when returning the shared
1236 * memory region identifier for an existing region, not when a new shared
1237 * memory region is created.
1238 * @perm contains the IPC permissions of the shared memory structure.
1239 * @shmflg contains the operation control flags.
1240 * Return 0 if permission is granted.
1241 * @shm_shmctl:
1242 * Check permission when a shared memory control operation specified by
1243 * @cmd is to be performed on the shared memory region with permissions @perm.
1244 * The @perm may be NULL, e.g. for IPC_INFO or SHM_INFO.
1245 * @perm contains the IPC permissions of the shared memory structure.
1246 * @cmd contains the operation to be performed.
1247 * Return 0 if permission is granted.
1248 * @shm_shmat:
1249 * Check permissions prior to allowing the shmat system call to attach the
1250 * shared memory segment with permissions @perm to the data segment of the
1251 * calling process. The attaching address is specified by @shmaddr.
1252 * @perm contains the IPC permissions of the shared memory structure.
1253 * @shmaddr contains the address to attach memory region to.
1254 * @shmflg contains the operational flags.
1255 * Return 0 if permission is granted.
1256 *
1257 * Security hooks for System V Semaphores
1258 *
1259 * @sem_alloc_security:
1260 * Allocate and attach a security structure to the @perm->security
1261 * field. The security field is initialized to NULL when the structure is
1262 * first created.
1263 * @perm contains the IPC permissions of the semaphore.
1264 * Return 0 if operation was successful and permission is granted.
1265 * @sem_free_security:
1266 * Deallocate security structure @perm->security for the semaphore.
1267 * @perm contains the IPC permissions of the semaphore.
1268 * @sem_associate:
1269 * Check permission when a semaphore is requested through the semget
1270 * system call. This hook is only called when returning the semaphore
1271 * identifier for an existing semaphore, not when a new one must be
1272 * created.
1273 * @perm contains the IPC permissions of the semaphore.
1274 * @semflg contains the operation control flags.
1275 * Return 0 if permission is granted.
1276 * @sem_semctl:
1277 * Check permission when a semaphore operation specified by @cmd is to be
1278 * performed on the semaphore. The @perm may be NULL, e.g. for
1279 * IPC_INFO or SEM_INFO.
1280 * @perm contains the IPC permissions of the semaphore. May be NULL.
1281 * @cmd contains the operation to be performed.
1282 * Return 0 if permission is granted.
1283 * @sem_semop:
1284 * Check permissions before performing operations on members of the
1285 * semaphore set. If the @alter flag is nonzero, the semaphore set
1286 * may be modified.
1287 * @perm contains the IPC permissions of the semaphore.
1288 * @sops contains the operations to perform.
1289 * @nsops contains the number of operations to perform.
1290 * @alter contains the flag indicating whether changes are to be made.
1291 * Return 0 if permission is granted.
1292 *
1293 * @binder_set_context_mgr:
1294 * Check whether @mgr is allowed to be the binder context manager.
1295 * @mgr contains the struct cred for the current binder process.
1296 * Return 0 if permission is granted.
1297 * @binder_transaction:
1298 * Check whether @from is allowed to invoke a binder transaction call
1299 * to @to.
1300 * @from contains the struct cred for the sending process.
1301 * @to contains the struct cred for the receiving process.
1302 * @binder_transfer_binder:
1303 * Check whether @from is allowed to transfer a binder reference to @to.
1304 * @from contains the struct cred for the sending process.
1305 * @to contains the struct cred for the receiving process.
1306 * @binder_transfer_file:
1307 * Check whether @from is allowed to transfer @file to @to.
1308 * @from contains the struct cred for the sending process.
1309 * @file contains the struct file being transferred.
1310 * @to contains the struct cred for the receiving process.
1311 *
1312 * @ptrace_access_check:
1313 * Check permission before allowing the current process to trace the
1314 * @child process.
1315 * Security modules may also want to perform a process tracing check
1316 * during an execve in the set_security or apply_creds hooks of
1317 * tracing check during an execve in the bprm_set_creds hook of
1318 * binprm_security_ops if the process is being traced and its security
1319 * attributes would be changed by the execve.
1320 * @child contains the task_struct structure for the target process.
1321 * @mode contains the PTRACE_MODE flags indicating the form of access.
1322 * Return 0 if permission is granted.
1323 * @ptrace_traceme:
1324 * Check that the @parent process has sufficient permission to trace the
1325 * current process before allowing the current process to present itself
1326 * to the @parent process for tracing.
1327 * @parent contains the task_struct structure for debugger process.
1328 * Return 0 if permission is granted.
1329 * @capget:
1330 * Get the @effective, @inheritable, and @permitted capability sets for
1331 * the @target process. The hook may also perform permission checking to
1332 * determine if the current process is allowed to see the capability sets
1333 * of the @target process.
1334 * @target contains the task_struct structure for target process.
1335 * @effective contains the effective capability set.
1336 * @inheritable contains the inheritable capability set.
1337 * @permitted contains the permitted capability set.
1338 * Return 0 if the capability sets were successfully obtained.
1339 * @capset:
1340 * Set the @effective, @inheritable, and @permitted capability sets for
1341 * the current process.
1342 * @new contains the new credentials structure for target process.
1343 * @old contains the current credentials structure for target process.
1344 * @effective contains the effective capability set.
1345 * @inheritable contains the inheritable capability set.
1346 * @permitted contains the permitted capability set.
1347 * Return 0 and update @new if permission is granted.
1348 * @capable:
1349 * Check whether the @tsk process has the @cap capability in the indicated
1350 * credentials.
1351 * @cred contains the credentials to use.
1352 * @ns contains the user namespace we want the capability in
1353 * @cap contains the capability <include/linux/capability.h>.
1354 * @opts contains options for the capable check <include/linux/security.h>
1355 * Return 0 if the capability is granted for @tsk.
1356 * @quotactl:
1357 * Check whether the quotactl syscall is allowed for this @sb.
1358 * @quota_on:
1359 * Check whether QUOTAON is allowed for this @dentry.
1360 * @syslog:
1361 * Check permission before accessing the kernel message ring or changing
1362 * logging to the console.
1363 * See the syslog(2) manual page for an explanation of the @type values.
1364 * @type contains the SYSLOG_ACTION_* constant from <include/linux/syslog.h>
1365 * Return 0 if permission is granted.
1366 * @settime:
1367 * Check permission to change the system time.
1368 * struct timespec64 is defined in <include/linux/time64.h> and timezone
1369 * is defined in <include/linux/time.h>
1370 * @ts contains new time
1371 * @tz contains new timezone
1372 * Return 0 if permission is granted.
1373 * @vm_enough_memory:
1374 * Check permissions for allocating a new virtual mapping.
1375 * @mm contains the mm struct it is being added to.
1376 * @pages contains the number of pages.
1377 * Return 0 if permission is granted.
1378 *
1379 * @ismaclabel:
1380 * Check if the extended attribute specified by @name
1381 * represents a MAC label. Returns 1 if name is a MAC
1382 * attribute otherwise returns 0.
1383 * @name full extended attribute name to check against
1384 * LSM as a MAC label.
1385 *
1386 * @secid_to_secctx:
1387 * Convert secid to security context. If secdata is NULL the length of
1388 * the result will be returned in seclen, but no secdata will be returned.
1389 * This does mean that the length could change between calls to check the
1390 * length and the next call which actually allocates and returns the
1391 * secdata.
1392 * @secid contains the security ID.
1393 * @secdata contains the pointer that stores the converted security
1394 * context.
1395 * @seclen pointer which contains the length of the data
1396 * @secctx_to_secid:
1397 * Convert security context to secid.
1398 * @secid contains the pointer to the generated security ID.
1399 * @secdata contains the security context.
1400 *
1401 * @release_secctx:
1402 * Release the security context.
1403 * @secdata contains the security context.
1404 * @seclen contains the length of the security context.
1405 *
1406 * Security hooks for Audit
1407 *
1408 * @audit_rule_init:
1409 * Allocate and initialize an LSM audit rule structure.
1410 * @field contains the required Audit action.
1411 * Fields flags are defined in <include/linux/audit.h>
1412 * @op contains the operator the rule uses.
1413 * @rulestr contains the context where the rule will be applied to.
1414 * @lsmrule contains a pointer to receive the result.
1415 * Return 0 if @lsmrule has been successfully set,
1416 * -EINVAL in case of an invalid rule.
1417 *
1418 * @audit_rule_known:
1419 * Specifies whether given @krule contains any fields related to
1420 * current LSM.
1421 * @krule contains the audit rule of interest.
1422 * Return 1 in case of relation found, 0 otherwise.
1423 *
1424 * @audit_rule_match:
1425 * Determine if given @secid matches a rule previously approved
1426 * by @audit_rule_known.
1427 * @secid contains the security id in question.
1428 * @field contains the field which relates to current LSM.
1429 * @op contains the operator that will be used for matching.
1430 * @lrule points to the audit rule that will be checked against.
1431 * Return 1 if secid matches the rule, 0 if it does not, -ERRNO on failure.
1432 *
1433 * @audit_rule_free:
1434 * Deallocate the LSM audit rule structure previously allocated by
1435 * audit_rule_init.
1436 * @lsmrule contains the allocated rule
1437 *
1438 * @inode_invalidate_secctx:
1439 * Notify the security module that it must revalidate the security context
1440 * of an inode.
1441 *
1442 * @inode_notifysecctx:
1443 * Notify the security module of what the security context of an inode
1444 * should be. Initializes the incore security context managed by the
1445 * security module for this inode. Example usage: NFS client invokes
1446 * this hook to initialize the security context in its incore inode to the
1447 * value provided by the server for the file when the server returned the
1448 * file's attributes to the client.
1449 * Must be called with inode->i_mutex locked.
1450 * @inode we wish to set the security context of.
1451 * @ctx contains the string which we wish to set in the inode.
1452 * @ctxlen contains the length of @ctx.
1453 *
1454 * @inode_setsecctx:
1455 * Change the security context of an inode. Updates the
1456 * incore security context managed by the security module and invokes the
1457 * fs code as needed (via __vfs_setxattr_noperm) to update any backing
1458 * xattrs that represent the context. Example usage: NFS server invokes
1459 * this hook to change the security context in its incore inode and on the
1460 * backing filesystem to a value provided by the client on a SETATTR
1461 * operation.
1462 * Must be called with inode->i_mutex locked.
1463 * @dentry contains the inode we wish to set the security context of.
1464 * @ctx contains the string which we wish to set in the inode.
1465 * @ctxlen contains the length of @ctx.
1466 *
1467 * @inode_getsecctx:
1468 * On success, returns 0 and fills out @ctx and @ctxlen with the security
1469 * context for the given @inode.
1470 * @inode we wish to get the security context of.
1471 * @ctx is a pointer in which to place the allocated security context.
1472 * @ctxlen points to the place to put the length of @ctx.
1473 *
1474 * Security hooks for the general notification queue:
1475 *
1476 * @post_notification:
1477 * Check to see if a watch notification can be posted to a particular
1478 * queue.
1479 * @w_cred: The credentials of the whoever set the watch.
1480 * @cred: The event-triggerer's credentials
1481 * @n: The notification being posted
1482 *
1483 * @watch_key:
1484 * Check to see if a process is allowed to watch for event notifications
1485 * from a key or keyring.
1486 * @key: The key to watch.
1487 *
1488 * Security hooks for using the eBPF maps and programs functionalities through
1489 * eBPF syscalls.
1490 *
1491 * @bpf:
1492 * Do a initial check for all bpf syscalls after the attribute is copied
1493 * into the kernel. The actual security module can implement their own
1494 * rules to check the specific cmd they need.
1495 *
1496 * @bpf_map:
1497 * Do a check when the kernel generate and return a file descriptor for
1498 * eBPF maps.
1499 *
1500 * @map: bpf map that we want to access
1501 * @mask: the access flags
1502 *
1503 * @bpf_prog:
1504 * Do a check when the kernel generate and return a file descriptor for
1505 * eBPF programs.
1506 *
1507 * @prog: bpf prog that userspace want to use.
1508 *
1509 * @bpf_map_alloc_security:
1510 * Initialize the security field inside bpf map.
1511 *
1512 * @bpf_map_free_security:
1513 * Clean up the security information stored inside bpf map.
1514 *
1515 * @bpf_prog_alloc_security:
1516 * Initialize the security field inside bpf program.
1517 *
1518 * @bpf_prog_free_security:
1519 * Clean up the security information stored inside bpf prog.
1520 *
1521 * @locked_down:
1522 * Determine whether a kernel feature that potentially enables arbitrary
1523 * code execution in kernel space should be permitted.
1524 *
1525 * @what: kernel feature being accessed
1526 *
1527 * Security hooks for perf events
1528 *
1529 * @perf_event_open:
1530 * Check whether the @type of perf_event_open syscall is allowed.
1531 * @perf_event_alloc:
1532 * Allocate and save perf_event security info.
1533 * @perf_event_free:
1534 * Release (free) perf_event security info.
1535 * @perf_event_read:
1536 * Read perf_event security info if allowed.
1537 * @perf_event_write:
1538 * Write perf_event security info if allowed.
1539 */
1540 union security_list_options {
1541 #define LSM_HOOK(RET, DEFAULT, NAME, ...) RET (*NAME)(__VA_ARGS__);
1542 #include "lsm_hook_defs.h"
1543 #undef LSM_HOOK
1544 };
1545
1546 struct security_hook_heads {
1547 #define LSM_HOOK(RET, DEFAULT, NAME, ...) struct hlist_head NAME;
1548 #include "lsm_hook_defs.h"
1549 #undef LSM_HOOK
1550 } __randomize_layout;
1551
1552 /*
1553 * Security module hook list structure.
1554 * For use with generic list macros for common operations.
1555 */
1556 struct security_hook_list {
1557 struct hlist_node list;
1558 struct hlist_head *head;
1559 union security_list_options hook;
1560 char *lsm;
1561 } __randomize_layout;
1562
1563 /*
1564 * Security blob size or offset data.
1565 */
1566 struct lsm_blob_sizes {
1567 int lbs_cred;
1568 int lbs_file;
1569 int lbs_inode;
1570 int lbs_ipc;
1571 int lbs_msg_msg;
1572 int lbs_task;
1573 };
1574
1575 /*
1576 * LSM_RET_VOID is used as the default value in LSM_HOOK definitions for void
1577 * LSM hooks (in include/linux/lsm_hook_defs.h).
1578 */
1579 #define LSM_RET_VOID ((void) 0)
1580
1581 /*
1582 * Initializing a security_hook_list structure takes
1583 * up a lot of space in a source file. This macro takes
1584 * care of the common case and reduces the amount of
1585 * text involved.
1586 */
1587 #define LSM_HOOK_INIT(HEAD, HOOK) \
1588 { .head = &security_hook_heads.HEAD, .hook = { .HEAD = HOOK } }
1589
1590 extern struct security_hook_heads security_hook_heads;
1591 extern char *lsm_names;
1592
1593 extern void security_add_hooks(struct security_hook_list *hooks, int count,
1594 char *lsm);
1595
1596 #define LSM_FLAG_LEGACY_MAJOR BIT(0)
1597 #define LSM_FLAG_EXCLUSIVE BIT(1)
1598
1599 enum lsm_order {
1600 LSM_ORDER_FIRST = -1, /* This is only for capabilities. */
1601 LSM_ORDER_MUTABLE = 0,
1602 };
1603
1604 struct lsm_info {
1605 const char *name; /* Required. */
1606 enum lsm_order order; /* Optional: default is LSM_ORDER_MUTABLE */
1607 unsigned long flags; /* Optional: flags describing LSM */
1608 int *enabled; /* Optional: controlled by CONFIG_LSM */
1609 int (*init)(void); /* Required. */
1610 struct lsm_blob_sizes *blobs; /* Optional: for blob sharing. */
1611 };
1612
1613 extern struct lsm_info __start_lsm_info[], __end_lsm_info[];
1614 extern struct lsm_info __start_early_lsm_info[], __end_early_lsm_info[];
1615
1616 #define DEFINE_LSM(lsm) \
1617 static struct lsm_info __lsm_##lsm \
1618 __used __section(".lsm_info.init") \
1619 __aligned(sizeof(unsigned long))
1620
1621 #define DEFINE_EARLY_LSM(lsm) \
1622 static struct lsm_info __early_lsm_##lsm \
1623 __used __section(".early_lsm_info.init") \
1624 __aligned(sizeof(unsigned long))
1625
1626 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
1627 /*
1628 * Assuring the safety of deleting a security module is up to
1629 * the security module involved. This may entail ordering the
1630 * module's hook list in a particular way, refusing to disable
1631 * the module once a policy is loaded or any number of other
1632 * actions better imagined than described.
1633 *
1634 * The name of the configuration option reflects the only module
1635 * that currently uses the mechanism. Any developer who thinks
1636 * disabling their module is a good idea needs to be at least as
1637 * careful as the SELinux team.
1638 */
security_delete_hooks(struct security_hook_list * hooks,int count)1639 static inline void security_delete_hooks(struct security_hook_list *hooks,
1640 int count)
1641 {
1642 int i;
1643
1644 for (i = 0; i < count; i++)
1645 hlist_del_rcu(&hooks[i].list);
1646 }
1647 #endif /* CONFIG_SECURITY_SELINUX_DISABLE */
1648
1649 /* Currently required to handle SELinux runtime hook disable. */
1650 #ifdef CONFIG_SECURITY_WRITABLE_HOOKS
1651 #define __lsm_ro_after_init
1652 #else
1653 #define __lsm_ro_after_init __ro_after_init
1654 #endif /* CONFIG_SECURITY_WRITABLE_HOOKS */
1655
1656 extern int lsm_inode_alloc(struct inode *inode);
1657
1658 #endif /* ! __LINUX_LSM_HOOKS_H */
1659