xref: /openbmc/linux/fs/ntfs3/xattr.c (revision 9322af3e6aeae04c7eda3e6a0c977e97a13cf6ed)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *
4  * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved.
5  *
6  */
7 
8 #include <linux/fs.h>
9 #include <linux/posix_acl.h>
10 #include <linux/posix_acl_xattr.h>
11 #include <linux/xattr.h>
12 
13 #include "debug.h"
14 #include "ntfs.h"
15 #include "ntfs_fs.h"
16 
17 // clang-format off
18 #define SYSTEM_DOS_ATTRIB    "system.dos_attrib"
19 #define SYSTEM_NTFS_ATTRIB   "system.ntfs_attrib"
20 #define SYSTEM_NTFS_SECURITY "system.ntfs_security"
21 // clang-format on
22 
23 static inline size_t unpacked_ea_size(const struct EA_FULL *ea)
24 {
25 	return ea->size ? le32_to_cpu(ea->size)
26 			: ALIGN(struct_size(ea, name,
27 					    1 + ea->name_len +
28 						    le16_to_cpu(ea->elength)),
29 				4);
30 }
31 
32 static inline size_t packed_ea_size(const struct EA_FULL *ea)
33 {
34 	return struct_size(ea, name,
35 			   1 + ea->name_len + le16_to_cpu(ea->elength)) -
36 	       offsetof(struct EA_FULL, flags);
37 }
38 
39 /*
40  * find_ea
41  *
42  * Assume there is at least one xattr in the list.
43  */
44 static inline bool find_ea(const struct EA_FULL *ea_all, u32 bytes,
45 			   const char *name, u8 name_len, u32 *off)
46 {
47 	*off = 0;
48 
49 	if (!ea_all || !bytes)
50 		return false;
51 
52 	for (;;) {
53 		const struct EA_FULL *ea = Add2Ptr(ea_all, *off);
54 		u32 next_off = *off + unpacked_ea_size(ea);
55 
56 		if (next_off > bytes)
57 			return false;
58 
59 		if (ea->name_len == name_len &&
60 		    !memcmp(ea->name, name, name_len))
61 			return true;
62 
63 		*off = next_off;
64 		if (next_off >= bytes)
65 			return false;
66 	}
67 }
68 
69 /*
70  * ntfs_read_ea - Read all extended attributes.
71  * @ea:		New allocated memory.
72  * @info:	Pointer into resident data.
73  */
74 static int ntfs_read_ea(struct ntfs_inode *ni, struct EA_FULL **ea,
75 			size_t add_bytes, const struct EA_INFO **info)
76 {
77 	int err;
78 	struct ntfs_sb_info *sbi = ni->mi.sbi;
79 	struct ATTR_LIST_ENTRY *le = NULL;
80 	struct ATTRIB *attr_info, *attr_ea;
81 	void *ea_p;
82 	u32 size;
83 
84 	static_assert(le32_to_cpu(ATTR_EA_INFO) < le32_to_cpu(ATTR_EA));
85 
86 	*ea = NULL;
87 	*info = NULL;
88 
89 	attr_info =
90 		ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, NULL);
91 	attr_ea =
92 		ni_find_attr(ni, attr_info, &le, ATTR_EA, NULL, 0, NULL, NULL);
93 
94 	if (!attr_ea || !attr_info)
95 		return 0;
96 
97 	*info = resident_data_ex(attr_info, sizeof(struct EA_INFO));
98 	if (!*info)
99 		return -EINVAL;
100 
101 	/* Check Ea limit. */
102 	size = le32_to_cpu((*info)->size);
103 	if (size > sbi->ea_max_size)
104 		return -EFBIG;
105 
106 	if (attr_size(attr_ea) > sbi->ea_max_size)
107 		return -EFBIG;
108 
109 	/* Allocate memory for packed Ea. */
110 	ea_p = kmalloc(size + add_bytes, GFP_NOFS);
111 	if (!ea_p)
112 		return -ENOMEM;
113 
114 	if (!size) {
115 		/* EA info persists, but xattr is empty. Looks like EA problem. */
116 	} else if (attr_ea->non_res) {
117 		struct runs_tree run;
118 
119 		run_init(&run);
120 
121 		err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &run, 0, size);
122 		if (!err)
123 			err = ntfs_read_run_nb(sbi, &run, 0, ea_p, size, NULL);
124 		run_close(&run);
125 
126 		if (err)
127 			goto out;
128 	} else {
129 		void *p = resident_data_ex(attr_ea, size);
130 
131 		if (!p) {
132 			err = -EINVAL;
133 			goto out;
134 		}
135 		memcpy(ea_p, p, size);
136 	}
137 
138 	memset(Add2Ptr(ea_p, size), 0, add_bytes);
139 	*ea = ea_p;
140 	return 0;
141 
142 out:
143 	kfree(ea_p);
144 	*ea = NULL;
145 	return err;
146 }
147 
148 /*
149  * ntfs_list_ea
150  *
151  * Copy a list of xattrs names into the buffer
152  * provided, or compute the buffer size required.
153  *
154  * Return:
155  * * Number of bytes used / required on
156  * * -ERRNO - on failure
157  */
158 static ssize_t ntfs_list_ea(struct ntfs_inode *ni, char *buffer,
159 			    size_t bytes_per_buffer)
160 {
161 	const struct EA_INFO *info;
162 	struct EA_FULL *ea_all = NULL;
163 	const struct EA_FULL *ea;
164 	u32 off, size;
165 	int err;
166 	size_t ret;
167 
168 	err = ntfs_read_ea(ni, &ea_all, 0, &info);
169 	if (err)
170 		return err;
171 
172 	if (!info || !ea_all)
173 		return 0;
174 
175 	size = le32_to_cpu(info->size);
176 
177 	/* Enumerate all xattrs. */
178 	for (ret = 0, off = 0; off < size; off += unpacked_ea_size(ea)) {
179 		ea = Add2Ptr(ea_all, off);
180 
181 		if (buffer) {
182 			if (ret + ea->name_len + 1 > bytes_per_buffer) {
183 				err = -ERANGE;
184 				goto out;
185 			}
186 
187 			memcpy(buffer + ret, ea->name, ea->name_len);
188 			buffer[ret + ea->name_len] = 0;
189 		}
190 
191 		ret += ea->name_len + 1;
192 	}
193 
194 out:
195 	kfree(ea_all);
196 	return err ? err : ret;
197 }
198 
199 static int ntfs_get_ea(struct inode *inode, const char *name, size_t name_len,
200 		       void *buffer, size_t size, size_t *required)
201 {
202 	struct ntfs_inode *ni = ntfs_i(inode);
203 	const struct EA_INFO *info;
204 	struct EA_FULL *ea_all = NULL;
205 	const struct EA_FULL *ea;
206 	u32 off, len;
207 	int err;
208 
209 	if (!(ni->ni_flags & NI_FLAG_EA))
210 		return -ENODATA;
211 
212 	if (!required)
213 		ni_lock(ni);
214 
215 	len = 0;
216 
217 	if (name_len > 255) {
218 		err = -ENAMETOOLONG;
219 		goto out;
220 	}
221 
222 	err = ntfs_read_ea(ni, &ea_all, 0, &info);
223 	if (err)
224 		goto out;
225 
226 	if (!info)
227 		goto out;
228 
229 	/* Enumerate all xattrs. */
230 	if (!find_ea(ea_all, le32_to_cpu(info->size), name, name_len, &off)) {
231 		err = -ENODATA;
232 		goto out;
233 	}
234 	ea = Add2Ptr(ea_all, off);
235 
236 	len = le16_to_cpu(ea->elength);
237 	if (!buffer) {
238 		err = 0;
239 		goto out;
240 	}
241 
242 	if (len > size) {
243 		err = -ERANGE;
244 		if (required)
245 			*required = len;
246 		goto out;
247 	}
248 
249 	memcpy(buffer, ea->name + ea->name_len + 1, len);
250 	err = 0;
251 
252 out:
253 	kfree(ea_all);
254 	if (!required)
255 		ni_unlock(ni);
256 
257 	return err ? err : len;
258 }
259 
260 static noinline int ntfs_set_ea(struct inode *inode, const char *name,
261 				size_t name_len, const void *value,
262 				size_t val_size, int flags, bool locked)
263 {
264 	struct ntfs_inode *ni = ntfs_i(inode);
265 	struct ntfs_sb_info *sbi = ni->mi.sbi;
266 	int err;
267 	struct EA_INFO ea_info;
268 	const struct EA_INFO *info;
269 	struct EA_FULL *new_ea;
270 	struct EA_FULL *ea_all = NULL;
271 	size_t add, new_pack;
272 	u32 off, size;
273 	__le16 size_pack;
274 	struct ATTRIB *attr;
275 	struct ATTR_LIST_ENTRY *le;
276 	struct mft_inode *mi;
277 	struct runs_tree ea_run;
278 	u64 new_sz;
279 	void *p;
280 
281 	if (!locked)
282 		ni_lock(ni);
283 
284 	run_init(&ea_run);
285 
286 	if (name_len > 255) {
287 		err = -ENAMETOOLONG;
288 		goto out;
289 	}
290 
291 	add = ALIGN(struct_size(ea_all, name, 1 + name_len + val_size), 4);
292 
293 	err = ntfs_read_ea(ni, &ea_all, add, &info);
294 	if (err)
295 		goto out;
296 
297 	if (!info) {
298 		memset(&ea_info, 0, sizeof(ea_info));
299 		size = 0;
300 		size_pack = 0;
301 	} else {
302 		memcpy(&ea_info, info, sizeof(ea_info));
303 		size = le32_to_cpu(ea_info.size);
304 		size_pack = ea_info.size_pack;
305 	}
306 
307 	if (info && find_ea(ea_all, size, name, name_len, &off)) {
308 		struct EA_FULL *ea;
309 		size_t ea_sz;
310 
311 		if (flags & XATTR_CREATE) {
312 			err = -EEXIST;
313 			goto out;
314 		}
315 
316 		ea = Add2Ptr(ea_all, off);
317 
318 		/*
319 		 * Check simple case when we try to insert xattr with the same value
320 		 * e.g. ntfs_save_wsl_perm
321 		 */
322 		if (val_size && le16_to_cpu(ea->elength) == val_size &&
323 		    !memcmp(ea->name + ea->name_len + 1, value, val_size)) {
324 			/* xattr already contains the required value. */
325 			goto out;
326 		}
327 
328 		/* Remove current xattr. */
329 		if (ea->flags & FILE_NEED_EA)
330 			le16_add_cpu(&ea_info.count, -1);
331 
332 		ea_sz = unpacked_ea_size(ea);
333 
334 		le16_add_cpu(&ea_info.size_pack, 0 - packed_ea_size(ea));
335 
336 		memmove(ea, Add2Ptr(ea, ea_sz), size - off - ea_sz);
337 
338 		size -= ea_sz;
339 		memset(Add2Ptr(ea_all, size), 0, ea_sz);
340 
341 		ea_info.size = cpu_to_le32(size);
342 
343 		if ((flags & XATTR_REPLACE) && !val_size) {
344 			/* Remove xattr. */
345 			goto update_ea;
346 		}
347 	} else {
348 		if (flags & XATTR_REPLACE) {
349 			err = -ENODATA;
350 			goto out;
351 		}
352 
353 		if (!ea_all) {
354 			ea_all = kzalloc(add, GFP_NOFS);
355 			if (!ea_all) {
356 				err = -ENOMEM;
357 				goto out;
358 			}
359 		}
360 	}
361 
362 	/* Append new xattr. */
363 	new_ea = Add2Ptr(ea_all, size);
364 	new_ea->size = cpu_to_le32(add);
365 	new_ea->flags = 0;
366 	new_ea->name_len = name_len;
367 	new_ea->elength = cpu_to_le16(val_size);
368 	memcpy(new_ea->name, name, name_len);
369 	new_ea->name[name_len] = 0;
370 	memcpy(new_ea->name + name_len + 1, value, val_size);
371 	new_pack = le16_to_cpu(ea_info.size_pack) + packed_ea_size(new_ea);
372 	ea_info.size_pack = cpu_to_le16(new_pack);
373 	/* New size of ATTR_EA. */
374 	size += add;
375 	ea_info.size = cpu_to_le32(size);
376 
377 	/*
378 	 * 1. Check ea_info.size_pack for overflow.
379 	 * 2. New attibute size must fit value from $AttrDef
380 	 */
381 	if (new_pack > 0xffff || size > sbi->ea_max_size) {
382 		ntfs_inode_warn(
383 			inode,
384 			"The size of extended attributes must not exceed 64KiB");
385 		err = -EFBIG; // -EINVAL?
386 		goto out;
387 	}
388 
389 update_ea:
390 
391 	if (!info) {
392 		/* Create xattr. */
393 		if (!size) {
394 			err = 0;
395 			goto out;
396 		}
397 
398 		err = ni_insert_resident(ni, sizeof(struct EA_INFO),
399 					 ATTR_EA_INFO, NULL, 0, NULL, NULL,
400 					 NULL);
401 		if (err)
402 			goto out;
403 
404 		err = ni_insert_resident(ni, 0, ATTR_EA, NULL, 0, NULL, NULL,
405 					 NULL);
406 		if (err)
407 			goto out;
408 	}
409 
410 	new_sz = size;
411 	err = attr_set_size(ni, ATTR_EA, NULL, 0, &ea_run, new_sz, &new_sz,
412 			    false, NULL);
413 	if (err)
414 		goto out;
415 
416 	le = NULL;
417 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, &mi);
418 	if (!attr) {
419 		err = -EINVAL;
420 		goto out;
421 	}
422 
423 	if (!size) {
424 		/* Delete xattr, ATTR_EA_INFO */
425 		ni_remove_attr_le(ni, attr, mi, le);
426 	} else {
427 		p = resident_data_ex(attr, sizeof(struct EA_INFO));
428 		if (!p) {
429 			err = -EINVAL;
430 			goto out;
431 		}
432 		memcpy(p, &ea_info, sizeof(struct EA_INFO));
433 		mi->dirty = true;
434 	}
435 
436 	le = NULL;
437 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA, NULL, 0, NULL, &mi);
438 	if (!attr) {
439 		err = -EINVAL;
440 		goto out;
441 	}
442 
443 	if (!size) {
444 		/* Delete xattr, ATTR_EA */
445 		ni_remove_attr_le(ni, attr, mi, le);
446 	} else if (attr->non_res) {
447 		err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &ea_run, 0,
448 					   size);
449 		if (err)
450 			goto out;
451 
452 		err = ntfs_sb_write_run(sbi, &ea_run, 0, ea_all, size, 0);
453 		if (err)
454 			goto out;
455 	} else {
456 		p = resident_data_ex(attr, size);
457 		if (!p) {
458 			err = -EINVAL;
459 			goto out;
460 		}
461 		memcpy(p, ea_all, size);
462 		mi->dirty = true;
463 	}
464 
465 	/* Check if we delete the last xattr. */
466 	if (size)
467 		ni->ni_flags |= NI_FLAG_EA;
468 	else
469 		ni->ni_flags &= ~NI_FLAG_EA;
470 
471 	if (ea_info.size_pack != size_pack)
472 		ni->ni_flags |= NI_FLAG_UPDATE_PARENT;
473 	mark_inode_dirty(&ni->vfs_inode);
474 
475 out:
476 	if (!locked)
477 		ni_unlock(ni);
478 
479 	run_close(&ea_run);
480 	kfree(ea_all);
481 
482 	return err;
483 }
484 
485 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
486 static struct posix_acl *ntfs_get_acl_ex(struct inode *inode, int type,
487 					 int locked)
488 {
489 	struct ntfs_inode *ni = ntfs_i(inode);
490 	const char *name;
491 	size_t name_len;
492 	struct posix_acl *acl;
493 	size_t req;
494 	int err;
495 	void *buf;
496 
497 	/* Allocate PATH_MAX bytes. */
498 	buf = __getname();
499 	if (!buf)
500 		return ERR_PTR(-ENOMEM);
501 
502 	/* Possible values of 'type' was already checked above. */
503 	if (type == ACL_TYPE_ACCESS) {
504 		name = XATTR_NAME_POSIX_ACL_ACCESS;
505 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
506 	} else {
507 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
508 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
509 	}
510 
511 	if (!locked)
512 		ni_lock(ni);
513 
514 	err = ntfs_get_ea(inode, name, name_len, buf, PATH_MAX, &req);
515 
516 	if (!locked)
517 		ni_unlock(ni);
518 
519 	/* Translate extended attribute to acl. */
520 	if (err >= 0) {
521 		acl = posix_acl_from_xattr(&init_user_ns, buf, err);
522 	} else if (err == -ENODATA) {
523 		acl = NULL;
524 	} else {
525 		acl = ERR_PTR(err);
526 	}
527 
528 	if (!IS_ERR(acl))
529 		set_cached_acl(inode, type, acl);
530 
531 	__putname(buf);
532 
533 	return acl;
534 }
535 
536 /*
537  * ntfs_get_acl - inode_operations::get_acl
538  */
539 struct posix_acl *ntfs_get_acl(struct inode *inode, int type, bool rcu)
540 {
541 	if (rcu)
542 		return ERR_PTR(-ECHILD);
543 
544 	return ntfs_get_acl_ex(inode, type, 0);
545 }
546 
547 static noinline int ntfs_set_acl_ex(struct user_namespace *mnt_userns,
548 				    struct inode *inode, struct posix_acl *acl,
549 				    int type, bool init_acl)
550 {
551 	const char *name;
552 	size_t size, name_len;
553 	void *value;
554 	int err;
555 	int flags;
556 	umode_t mode;
557 
558 	if (S_ISLNK(inode->i_mode))
559 		return -EOPNOTSUPP;
560 
561 	mode = inode->i_mode;
562 	switch (type) {
563 	case ACL_TYPE_ACCESS:
564 		/* Do not change i_mode if we are in init_acl */
565 		if (acl && !init_acl) {
566 			err = posix_acl_update_mode(mnt_userns, inode, &mode,
567 						    &acl);
568 			if (err)
569 				return err;
570 		}
571 		name = XATTR_NAME_POSIX_ACL_ACCESS;
572 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
573 		break;
574 
575 	case ACL_TYPE_DEFAULT:
576 		if (!S_ISDIR(inode->i_mode))
577 			return acl ? -EACCES : 0;
578 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
579 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
580 		break;
581 
582 	default:
583 		return -EINVAL;
584 	}
585 
586 	if (!acl) {
587 		/* Remove xattr if it can be presented via mode. */
588 		size = 0;
589 		value = NULL;
590 		flags = XATTR_REPLACE;
591 	} else {
592 		size = posix_acl_xattr_size(acl->a_count);
593 		value = kmalloc(size, GFP_NOFS);
594 		if (!value)
595 			return -ENOMEM;
596 		err = posix_acl_to_xattr(&init_user_ns, acl, value, size);
597 		if (err < 0)
598 			goto out;
599 		flags = 0;
600 	}
601 
602 	err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0);
603 	if (err == -ENODATA && !size)
604 		err = 0; /* Removing non existed xattr. */
605 	if (!err) {
606 		set_cached_acl(inode, type, acl);
607 		if (inode->i_mode != mode) {
608 			inode->i_mode = mode;
609 			mark_inode_dirty(inode);
610 		}
611 	}
612 
613 out:
614 	kfree(value);
615 
616 	return err;
617 }
618 
619 /*
620  * ntfs_set_acl - inode_operations::set_acl
621  */
622 int ntfs_set_acl(struct user_namespace *mnt_userns, struct dentry *dentry,
623 		 struct posix_acl *acl, int type)
624 {
625 	return ntfs_set_acl_ex(mnt_userns, d_inode(dentry), acl, type, false);
626 }
627 
628 /*
629  * ntfs_init_acl - Initialize the ACLs of a new inode.
630  *
631  * Called from ntfs_create_inode().
632  */
633 int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
634 		  struct inode *dir)
635 {
636 	struct posix_acl *default_acl, *acl;
637 	int err;
638 
639 	err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
640 	if (err)
641 		return err;
642 
643 	if (default_acl) {
644 		err = ntfs_set_acl_ex(mnt_userns, inode, default_acl,
645 				      ACL_TYPE_DEFAULT, true);
646 		posix_acl_release(default_acl);
647 	} else {
648 		inode->i_default_acl = NULL;
649 	}
650 
651 	if (acl) {
652 		if (!err)
653 			err = ntfs_set_acl_ex(mnt_userns, inode, acl,
654 					      ACL_TYPE_ACCESS, true);
655 		posix_acl_release(acl);
656 	} else {
657 		inode->i_acl = NULL;
658 	}
659 
660 	return err;
661 }
662 #endif
663 
664 /*
665  * ntfs_acl_chmod - Helper for ntfs3_setattr().
666  */
667 int ntfs_acl_chmod(struct user_namespace *mnt_userns, struct dentry *dentry)
668 {
669 	struct inode *inode = d_inode(dentry);
670 	struct super_block *sb = inode->i_sb;
671 
672 	if (!(sb->s_flags & SB_POSIXACL))
673 		return 0;
674 
675 	if (S_ISLNK(inode->i_mode))
676 		return -EOPNOTSUPP;
677 
678 	return posix_acl_chmod(mnt_userns, dentry, inode->i_mode);
679 }
680 
681 /*
682  * ntfs_permission - inode_operations::permission
683  */
684 int ntfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
685 		    int mask)
686 {
687 	if (ntfs_sb(inode->i_sb)->options->noacsrules) {
688 		/* "No access rules" mode - Allow all changes. */
689 		return 0;
690 	}
691 
692 	return generic_permission(mnt_userns, inode, mask);
693 }
694 
695 /*
696  * ntfs_listxattr - inode_operations::listxattr
697  */
698 ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
699 {
700 	struct inode *inode = d_inode(dentry);
701 	struct ntfs_inode *ni = ntfs_i(inode);
702 	ssize_t ret;
703 
704 	if (!(ni->ni_flags & NI_FLAG_EA)) {
705 		/* no xattr in file */
706 		return 0;
707 	}
708 
709 	ni_lock(ni);
710 
711 	ret = ntfs_list_ea(ni, buffer, size);
712 
713 	ni_unlock(ni);
714 
715 	return ret;
716 }
717 
718 static int ntfs_getxattr(const struct xattr_handler *handler, struct dentry *de,
719 			 struct inode *inode, const char *name, void *buffer,
720 			 size_t size)
721 {
722 	int err;
723 	struct ntfs_inode *ni = ntfs_i(inode);
724 	size_t name_len = strlen(name);
725 
726 	/* Dispatch request. */
727 	if (name_len == sizeof(SYSTEM_DOS_ATTRIB) - 1 &&
728 	    !memcmp(name, SYSTEM_DOS_ATTRIB, sizeof(SYSTEM_DOS_ATTRIB))) {
729 		/* system.dos_attrib */
730 		if (!buffer) {
731 			err = sizeof(u8);
732 		} else if (size < sizeof(u8)) {
733 			err = -ENODATA;
734 		} else {
735 			err = sizeof(u8);
736 			*(u8 *)buffer = le32_to_cpu(ni->std_fa);
737 		}
738 		goto out;
739 	}
740 
741 	if (name_len == sizeof(SYSTEM_NTFS_ATTRIB) - 1 &&
742 	    !memcmp(name, SYSTEM_NTFS_ATTRIB, sizeof(SYSTEM_NTFS_ATTRIB))) {
743 		/* system.ntfs_attrib */
744 		if (!buffer) {
745 			err = sizeof(u32);
746 		} else if (size < sizeof(u32)) {
747 			err = -ENODATA;
748 		} else {
749 			err = sizeof(u32);
750 			*(u32 *)buffer = le32_to_cpu(ni->std_fa);
751 		}
752 		goto out;
753 	}
754 
755 	if (name_len == sizeof(SYSTEM_NTFS_SECURITY) - 1 &&
756 	    !memcmp(name, SYSTEM_NTFS_SECURITY, sizeof(SYSTEM_NTFS_SECURITY))) {
757 		/* system.ntfs_security*/
758 		struct SECURITY_DESCRIPTOR_RELATIVE *sd = NULL;
759 		size_t sd_size = 0;
760 
761 		if (!is_ntfs3(ni->mi.sbi)) {
762 			/* We should get nt4 security. */
763 			err = -EINVAL;
764 			goto out;
765 		} else if (le32_to_cpu(ni->std_security_id) <
766 			   SECURITY_ID_FIRST) {
767 			err = -ENOENT;
768 			goto out;
769 		}
770 
771 		err = ntfs_get_security_by_id(ni->mi.sbi, ni->std_security_id,
772 					      &sd, &sd_size);
773 		if (err)
774 			goto out;
775 
776 		if (!is_sd_valid(sd, sd_size)) {
777 			ntfs_inode_warn(
778 				inode,
779 				"looks like you get incorrect security descriptor id=%u",
780 				ni->std_security_id);
781 		}
782 
783 		if (!buffer) {
784 			err = sd_size;
785 		} else if (size < sd_size) {
786 			err = -ENODATA;
787 		} else {
788 			err = sd_size;
789 			memcpy(buffer, sd, sd_size);
790 		}
791 		kfree(sd);
792 		goto out;
793 	}
794 
795 	/* Deal with NTFS extended attribute. */
796 	err = ntfs_get_ea(inode, name, name_len, buffer, size, NULL);
797 
798 out:
799 	return err;
800 }
801 
802 /*
803  * ntfs_setxattr - inode_operations::setxattr
804  */
805 static noinline int ntfs_setxattr(const struct xattr_handler *handler,
806 				  struct user_namespace *mnt_userns,
807 				  struct dentry *de, struct inode *inode,
808 				  const char *name, const void *value,
809 				  size_t size, int flags)
810 {
811 	int err = -EINVAL;
812 	struct ntfs_inode *ni = ntfs_i(inode);
813 	size_t name_len = strlen(name);
814 	enum FILE_ATTRIBUTE new_fa;
815 
816 	/* Dispatch request. */
817 	if (name_len == sizeof(SYSTEM_DOS_ATTRIB) - 1 &&
818 	    !memcmp(name, SYSTEM_DOS_ATTRIB, sizeof(SYSTEM_DOS_ATTRIB))) {
819 		if (sizeof(u8) != size)
820 			goto out;
821 		new_fa = cpu_to_le32(*(u8 *)value);
822 		goto set_new_fa;
823 	}
824 
825 	if (name_len == sizeof(SYSTEM_NTFS_ATTRIB) - 1 &&
826 	    !memcmp(name, SYSTEM_NTFS_ATTRIB, sizeof(SYSTEM_NTFS_ATTRIB))) {
827 		if (size != sizeof(u32))
828 			goto out;
829 		new_fa = cpu_to_le32(*(u32 *)value);
830 
831 		if (S_ISREG(inode->i_mode)) {
832 			/* Process compressed/sparsed in special way. */
833 			ni_lock(ni);
834 			err = ni_new_attr_flags(ni, new_fa);
835 			ni_unlock(ni);
836 			if (err)
837 				goto out;
838 		}
839 set_new_fa:
840 		/*
841 		 * Thanks Mark Harmstone:
842 		 * Keep directory bit consistency.
843 		 */
844 		if (S_ISDIR(inode->i_mode))
845 			new_fa |= FILE_ATTRIBUTE_DIRECTORY;
846 		else
847 			new_fa &= ~FILE_ATTRIBUTE_DIRECTORY;
848 
849 		if (ni->std_fa != new_fa) {
850 			ni->std_fa = new_fa;
851 			if (new_fa & FILE_ATTRIBUTE_READONLY)
852 				inode->i_mode &= ~0222;
853 			else
854 				inode->i_mode |= 0222;
855 			/* Std attribute always in primary record. */
856 			ni->mi.dirty = true;
857 			mark_inode_dirty(inode);
858 		}
859 		err = 0;
860 
861 		goto out;
862 	}
863 
864 	if (name_len == sizeof(SYSTEM_NTFS_SECURITY) - 1 &&
865 	    !memcmp(name, SYSTEM_NTFS_SECURITY, sizeof(SYSTEM_NTFS_SECURITY))) {
866 		/* system.ntfs_security*/
867 		__le32 security_id;
868 		bool inserted;
869 		struct ATTR_STD_INFO5 *std;
870 
871 		if (!is_ntfs3(ni->mi.sbi)) {
872 			/*
873 			 * We should replace ATTR_SECURE.
874 			 * Skip this way cause it is nt4 feature.
875 			 */
876 			err = -EINVAL;
877 			goto out;
878 		}
879 
880 		if (!is_sd_valid(value, size)) {
881 			err = -EINVAL;
882 			ntfs_inode_warn(
883 				inode,
884 				"you try to set invalid security descriptor");
885 			goto out;
886 		}
887 
888 		err = ntfs_insert_security(ni->mi.sbi, value, size,
889 					   &security_id, &inserted);
890 		if (err)
891 			goto out;
892 
893 		ni_lock(ni);
894 		std = ni_std5(ni);
895 		if (!std) {
896 			err = -EINVAL;
897 		} else if (std->security_id != security_id) {
898 			std->security_id = ni->std_security_id = security_id;
899 			/* Std attribute always in primary record. */
900 			ni->mi.dirty = true;
901 			mark_inode_dirty(&ni->vfs_inode);
902 		}
903 		ni_unlock(ni);
904 		goto out;
905 	}
906 
907 	/* Deal with NTFS extended attribute. */
908 	err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0);
909 
910 out:
911 	inode->i_ctime = current_time(inode);
912 	mark_inode_dirty(inode);
913 
914 	return err;
915 }
916 
917 /*
918  * ntfs_save_wsl_perm
919  *
920  * save uid/gid/mode in xattr
921  */
922 int ntfs_save_wsl_perm(struct inode *inode)
923 {
924 	int err;
925 	__le32 value;
926 	struct ntfs_inode *ni = ntfs_i(inode);
927 
928 	ni_lock(ni);
929 	value = cpu_to_le32(i_uid_read(inode));
930 	err = ntfs_set_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value,
931 			  sizeof(value), 0, true); /* true == already locked. */
932 	if (err)
933 		goto out;
934 
935 	value = cpu_to_le32(i_gid_read(inode));
936 	err = ntfs_set_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value,
937 			  sizeof(value), 0, true);
938 	if (err)
939 		goto out;
940 
941 	value = cpu_to_le32(inode->i_mode);
942 	err = ntfs_set_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value,
943 			  sizeof(value), 0, true);
944 	if (err)
945 		goto out;
946 
947 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
948 		value = cpu_to_le32(inode->i_rdev);
949 		err = ntfs_set_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &value,
950 				  sizeof(value), 0, true);
951 		if (err)
952 			goto out;
953 	}
954 
955 out:
956 	ni_unlock(ni);
957 	/* In case of error should we delete all WSL xattr? */
958 	return err;
959 }
960 
961 /*
962  * ntfs_get_wsl_perm
963  *
964  * get uid/gid/mode from xattr
965  * it is called from ntfs_iget5->ntfs_read_mft
966  */
967 void ntfs_get_wsl_perm(struct inode *inode)
968 {
969 	size_t sz;
970 	__le32 value[3];
971 
972 	if (ntfs_get_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value[0],
973 			sizeof(value[0]), &sz) == sizeof(value[0]) &&
974 	    ntfs_get_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value[1],
975 			sizeof(value[1]), &sz) == sizeof(value[1]) &&
976 	    ntfs_get_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value[2],
977 			sizeof(value[2]), &sz) == sizeof(value[2])) {
978 		i_uid_write(inode, (uid_t)le32_to_cpu(value[0]));
979 		i_gid_write(inode, (gid_t)le32_to_cpu(value[1]));
980 		inode->i_mode = le32_to_cpu(value[2]);
981 
982 		if (ntfs_get_ea(inode, "$LXDEV", sizeof("$$LXDEV") - 1,
983 				&value[0], sizeof(value),
984 				&sz) == sizeof(value[0])) {
985 			inode->i_rdev = le32_to_cpu(value[0]);
986 		}
987 	}
988 }
989 
990 static bool ntfs_xattr_user_list(struct dentry *dentry)
991 {
992 	return true;
993 }
994 
995 // clang-format off
996 static const struct xattr_handler ntfs_other_xattr_handler = {
997 	.prefix	= "",
998 	.get	= ntfs_getxattr,
999 	.set	= ntfs_setxattr,
1000 	.list	= ntfs_xattr_user_list,
1001 };
1002 
1003 const struct xattr_handler *ntfs_xattr_handlers[] = {
1004 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
1005 	&posix_acl_access_xattr_handler,
1006 	&posix_acl_default_xattr_handler,
1007 #endif
1008 	&ntfs_other_xattr_handler,
1009 	NULL,
1010 };
1011 // clang-format on
1012