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_ATTRIB_BE "system.ntfs_attrib_be"
21 #define SYSTEM_NTFS_SECURITY "system.ntfs_security"
22 // clang-format on
23
unpacked_ea_size(const struct EA_FULL * ea)24 static inline size_t unpacked_ea_size(const struct EA_FULL *ea)
25 {
26 return ea->size ? le32_to_cpu(ea->size) :
27 ALIGN(struct_size(ea, name,
28 1 + ea->name_len +
29 le16_to_cpu(ea->elength)),
30 4);
31 }
32
packed_ea_size(const struct EA_FULL * ea)33 static inline size_t packed_ea_size(const struct EA_FULL *ea)
34 {
35 return struct_size(ea, name,
36 1 + ea->name_len + le16_to_cpu(ea->elength)) -
37 offsetof(struct EA_FULL, flags);
38 }
39
40 /*
41 * find_ea
42 *
43 * Assume there is at least one xattr in the list.
44 */
find_ea(const struct EA_FULL * ea_all,u32 bytes,const char * name,u8 name_len,u32 * off,u32 * ea_sz)45 static inline bool find_ea(const struct EA_FULL *ea_all, u32 bytes,
46 const char *name, u8 name_len, u32 *off, u32 *ea_sz)
47 {
48 u32 ea_size;
49
50 *off = 0;
51 if (!ea_all)
52 return false;
53
54 for (; *off < bytes; *off += ea_size) {
55 const struct EA_FULL *ea = Add2Ptr(ea_all, *off);
56 ea_size = unpacked_ea_size(ea);
57 if (ea->name_len == name_len &&
58 !memcmp(ea->name, name, name_len)) {
59 if (ea_sz)
60 *ea_sz = ea_size;
61 return true;
62 }
63 }
64
65 return false;
66 }
67
68 /*
69 * ntfs_read_ea - Read all extended attributes.
70 * @ea: New allocated memory.
71 * @info: Pointer into resident data.
72 */
ntfs_read_ea(struct ntfs_inode * ni,struct EA_FULL ** ea,size_t add_bytes,const struct EA_INFO ** info)73 static int ntfs_read_ea(struct ntfs_inode *ni, struct EA_FULL **ea,
74 size_t add_bytes, const struct EA_INFO **info)
75 {
76 int err = -EINVAL;
77 struct ntfs_sb_info *sbi = ni->mi.sbi;
78 struct ATTR_LIST_ENTRY *le = NULL;
79 struct ATTRIB *attr_info, *attr_ea;
80 void *ea_p;
81 u32 size, off, ea_size;
82
83 static_assert(le32_to_cpu(ATTR_EA_INFO) < le32_to_cpu(ATTR_EA));
84
85 *ea = NULL;
86 *info = NULL;
87
88 attr_info =
89 ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, NULL);
90 attr_ea =
91 ni_find_attr(ni, attr_info, &le, ATTR_EA, NULL, 0, NULL, NULL);
92
93 if (!attr_ea || !attr_info)
94 return 0;
95
96 *info = resident_data_ex(attr_info, sizeof(struct EA_INFO));
97 if (!*info)
98 goto out;
99
100 /* Check Ea limit. */
101 size = le32_to_cpu((*info)->size);
102 if (size > sbi->ea_max_size) {
103 err = -EFBIG;
104 goto out;
105 }
106
107 if (attr_size(attr_ea) > sbi->ea_max_size) {
108 err = -EFBIG;
109 goto out;
110 }
111
112 if (!size) {
113 /* EA info persists, but xattr is empty. Looks like EA problem. */
114 goto out;
115 }
116
117 /* Allocate memory for packed Ea. */
118 ea_p = kmalloc(size_add(size, add_bytes), GFP_NOFS);
119 if (!ea_p)
120 return -ENOMEM;
121
122 if (attr_ea->non_res) {
123 struct runs_tree run;
124
125 run_init(&run);
126
127 err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &run, 0, size);
128 if (!err)
129 err = ntfs_read_run_nb(sbi, &run, 0, ea_p, size, NULL);
130 run_close(&run);
131
132 if (err)
133 goto out1;
134 } else {
135 void *p = resident_data_ex(attr_ea, size);
136
137 if (!p)
138 goto out1;
139 memcpy(ea_p, p, size);
140 }
141
142 memset(Add2Ptr(ea_p, size), 0, add_bytes);
143
144 err = -EINVAL;
145 /* Check all attributes for consistency. */
146 for (off = 0; off < size; off += ea_size) {
147 const struct EA_FULL *ef = Add2Ptr(ea_p, off);
148 u32 bytes = size - off;
149 size_t need;
150
151 /* Check if we can use field ea->size. */
152 if (bytes < sizeof(ef->size))
153 goto out1;
154
155 /* Check if we can use fields ef->name_len and ef->elength. */
156 if (bytes < offsetof(struct EA_FULL, name))
157 goto out1;
158
159 /* Size needed to hold this record's name and value. */
160 need = struct_size(ef, name,
161 1 + ef->name_len + le16_to_cpu(ef->elength));
162
163 if (ef->size) {
164 ea_size = le32_to_cpu(ef->size);
165 /* ef->size must fit the list and cover the record. */
166 if (ea_size > bytes || ea_size < need)
167 goto out1;
168 continue;
169 }
170
171 ea_size = ALIGN(need, 4);
172 if (ea_size > bytes)
173 goto out1;
174 }
175
176 *ea = ea_p;
177 return 0;
178
179 out1:
180 kfree(ea_p);
181 out:
182 ntfs_set_state(sbi, NTFS_DIRTY_DIRTY);
183 return err;
184 }
185
186 /*
187 * ntfs_list_ea
188 *
189 * Copy a list of xattrs names into the buffer
190 * provided, or compute the buffer size required.
191 *
192 * Return:
193 * * Number of bytes used / required on
194 * * -ERRNO - on failure
195 */
ntfs_list_ea(struct ntfs_inode * ni,char * buffer,size_t bytes_per_buffer)196 static ssize_t ntfs_list_ea(struct ntfs_inode *ni, char *buffer,
197 size_t bytes_per_buffer)
198 {
199 const struct EA_INFO *info;
200 struct EA_FULL *ea_all = NULL;
201 u32 off, size;
202 int err;
203 size_t ret;
204
205 err = ntfs_read_ea(ni, &ea_all, 0, &info);
206 if (err)
207 return err;
208
209 if (!info || !ea_all)
210 return 0;
211
212 size = le32_to_cpu(info->size);
213
214 /* Enumerate all xattrs. */
215 ret = 0;
216 off = 0;
217 while (off + sizeof(struct EA_FULL) < size) {
218 const struct EA_FULL *ea = Add2Ptr(ea_all, off);
219 int ea_size = unpacked_ea_size(ea);
220 u8 name_len = ea->name_len;
221
222 if (!name_len)
223 break;
224
225 if (name_len > ea_size) {
226 ntfs_set_state(ni->mi.sbi, NTFS_DIRTY_ERROR);
227 err = -EINVAL; /* corrupted fs. */
228 break;
229 }
230
231 if (buffer) {
232 /* Check if we can use field ea->name */
233 if (off + ea_size > size)
234 break;
235
236 if (ret + name_len + 1 > bytes_per_buffer) {
237 err = -ERANGE;
238 goto out;
239 }
240
241 memcpy(buffer + ret, ea->name, name_len);
242 buffer[ret + name_len] = 0;
243 }
244
245 ret += name_len + 1;
246 off += ea_size;
247 }
248
249 out:
250 kfree(ea_all);
251 return err ? err : ret;
252 }
253
ntfs_get_ea(struct inode * inode,const char * name,size_t name_len,void * buffer,size_t size,size_t * required)254 static int ntfs_get_ea(struct inode *inode, const char *name, size_t name_len,
255 void *buffer, size_t size, size_t *required)
256 {
257 struct ntfs_inode *ni = ntfs_i(inode);
258 const struct EA_INFO *info;
259 struct EA_FULL *ea_all = NULL;
260 const struct EA_FULL *ea;
261 u32 off, len;
262 int err;
263
264 if (!(ni->ni_flags & NI_FLAG_EA))
265 return -ENODATA;
266
267 if (!required)
268 ni_lock(ni);
269
270 len = 0;
271
272 if (name_len > 255) {
273 err = -ENAMETOOLONG;
274 goto out;
275 }
276
277 err = ntfs_read_ea(ni, &ea_all, 0, &info);
278 if (err)
279 goto out;
280
281 if (!info)
282 goto out;
283
284 /* Enumerate all xattrs. */
285 if (!find_ea(ea_all, le32_to_cpu(info->size), name, name_len, &off,
286 NULL)) {
287 err = -ENODATA;
288 goto out;
289 }
290 ea = Add2Ptr(ea_all, off);
291
292 len = le16_to_cpu(ea->elength);
293 if (!buffer) {
294 err = 0;
295 goto out;
296 }
297
298 if (len > size) {
299 err = -ERANGE;
300 if (required)
301 *required = len;
302 goto out;
303 }
304
305 memcpy(buffer, ea->name + ea->name_len + 1, len);
306 err = 0;
307
308 out:
309 kfree(ea_all);
310 if (!required)
311 ni_unlock(ni);
312
313 return err ? err : len;
314 }
315
ntfs_set_ea(struct inode * inode,const char * name,size_t name_len,const void * value,size_t val_size,int flags,bool locked,__le32 * ea_size)316 static noinline int ntfs_set_ea(struct inode *inode, const char *name,
317 size_t name_len, const void *value,
318 size_t val_size, int flags, bool locked,
319 __le32 *ea_size)
320 {
321 struct ntfs_inode *ni = ntfs_i(inode);
322 struct ntfs_sb_info *sbi = ni->mi.sbi;
323 int err;
324 struct EA_INFO ea_info;
325 const struct EA_INFO *info;
326 struct EA_FULL *new_ea;
327 struct EA_FULL *ea_all = NULL;
328 size_t add, new_pack;
329 u32 off, size, ea_sz;
330 __le16 size_pack;
331 struct ATTRIB *attr;
332 struct ATTR_LIST_ENTRY *le;
333 struct mft_inode *mi;
334 struct runs_tree ea_run;
335 u64 new_sz;
336 void *p;
337
338 if (!locked)
339 ni_lock(ni);
340
341 run_init(&ea_run);
342
343 if (name_len > 255) {
344 err = -ENAMETOOLONG;
345 goto out;
346 }
347
348 add = ALIGN(struct_size(ea_all, name, 1 + name_len + val_size), 4);
349
350 err = ntfs_read_ea(ni, &ea_all, add, &info);
351 if (err)
352 goto out;
353
354 if (!info) {
355 memset(&ea_info, 0, sizeof(ea_info));
356 size = 0;
357 size_pack = 0;
358 } else {
359 memcpy(&ea_info, info, sizeof(ea_info));
360 size = le32_to_cpu(ea_info.size);
361 size_pack = ea_info.size_pack;
362 }
363
364 if (info && find_ea(ea_all, size, name, name_len, &off, &ea_sz)) {
365 struct EA_FULL *ea;
366
367 if (flags & XATTR_CREATE) {
368 err = -EEXIST;
369 goto out;
370 }
371
372 ea = Add2Ptr(ea_all, off);
373
374 /*
375 * Check simple case when we try to insert xattr with the same value
376 * e.g. ntfs_save_wsl_perm
377 */
378 if (val_size && le16_to_cpu(ea->elength) == val_size &&
379 !memcmp(ea->name + ea->name_len + 1, value, val_size)) {
380 /* xattr already contains the required value. */
381 goto out;
382 }
383
384 /* Remove current xattr. */
385 if (ea->flags & FILE_NEED_EA)
386 le16_add_cpu(&ea_info.count, -1);
387
388 le16_add_cpu(&ea_info.size_pack, 0 - packed_ea_size(ea));
389
390 memmove(ea, Add2Ptr(ea, ea_sz), size - off - ea_sz);
391
392 size -= ea_sz;
393 memset(Add2Ptr(ea_all, size), 0, ea_sz);
394
395 ea_info.size = cpu_to_le32(size);
396
397 if ((flags & XATTR_REPLACE) && !val_size) {
398 /* Remove xattr. */
399 goto update_ea;
400 }
401 } else {
402 if (flags & XATTR_REPLACE) {
403 err = -ENODATA;
404 goto out;
405 }
406
407 if (!ea_all) {
408 ea_all = kzalloc(add, GFP_NOFS);
409 if (!ea_all) {
410 err = -ENOMEM;
411 goto out;
412 }
413 }
414 }
415
416 /* Append new xattr. */
417 new_ea = Add2Ptr(ea_all, size);
418 new_ea->size = cpu_to_le32(add);
419 new_ea->flags = 0;
420 new_ea->name_len = name_len;
421 new_ea->elength = cpu_to_le16(val_size);
422 memcpy(new_ea->name, name, name_len);
423 new_ea->name[name_len] = 0;
424 memcpy(new_ea->name + name_len + 1, value, val_size);
425 new_pack = le16_to_cpu(ea_info.size_pack) + packed_ea_size(new_ea);
426 ea_info.size_pack = cpu_to_le16(new_pack);
427 /* New size of ATTR_EA. */
428 size += add;
429 ea_info.size = cpu_to_le32(size);
430
431 /*
432 * 1. Check ea_info.size_pack for overflow.
433 * 2. New attribute size must fit value from $AttrDef
434 */
435 if (new_pack > 0xffff || size > sbi->ea_max_size) {
436 ntfs_inode_warn(
437 inode,
438 "The size of extended attributes must not exceed 64KiB");
439 err = -EFBIG; // -EINVAL?
440 goto out;
441 }
442
443 update_ea:
444
445 if (!info) {
446 /* Create xattr. */
447 if (!size) {
448 err = 0;
449 goto out;
450 }
451
452 err = ni_insert_resident(ni, sizeof(struct EA_INFO),
453 ATTR_EA_INFO, NULL, 0, NULL, NULL,
454 NULL);
455 if (err)
456 goto out;
457
458 err = ni_insert_resident(ni, 0, ATTR_EA, NULL, 0, NULL, NULL,
459 NULL);
460 if (err)
461 goto out;
462 }
463
464 new_sz = size;
465 err = attr_set_size(ni, ATTR_EA, NULL, 0, &ea_run, new_sz, &new_sz,
466 false);
467 if (err)
468 goto out;
469
470 le = NULL;
471 attr = ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, &mi);
472 if (!attr) {
473 err = -EINVAL;
474 goto out;
475 }
476
477 if (!size) {
478 /* Delete xattr, ATTR_EA_INFO */
479 ni_remove_attr_le(ni, attr, mi, le);
480 } else {
481 p = resident_data_ex(attr, sizeof(struct EA_INFO));
482 if (!p) {
483 err = -EINVAL;
484 goto out;
485 }
486 memcpy(p, &ea_info, sizeof(struct EA_INFO));
487 mi->dirty = true;
488 }
489
490 le = NULL;
491 attr = ni_find_attr(ni, NULL, &le, ATTR_EA, NULL, 0, NULL, &mi);
492 if (!attr) {
493 err = -EINVAL;
494 goto out;
495 }
496
497 if (!size) {
498 /* Delete xattr, ATTR_EA */
499 ni_remove_attr_le(ni, attr, mi, le);
500 } else if (attr->non_res) {
501 err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &ea_run, 0,
502 size);
503 if (err)
504 goto out;
505
506 err = ntfs_sb_write_run(sbi, &ea_run, 0, ea_all, size, 0);
507 if (err)
508 goto out;
509 } else {
510 p = resident_data_ex(attr, size);
511 if (!p) {
512 err = -EINVAL;
513 goto out;
514 }
515 memcpy(p, ea_all, size);
516 mi->dirty = true;
517 }
518
519 /* Check if we delete the last xattr. */
520 if (size)
521 ni->ni_flags |= NI_FLAG_EA;
522 else
523 ni->ni_flags &= ~NI_FLAG_EA;
524
525 if (ea_info.size_pack != size_pack)
526 ni->ni_flags |= NI_FLAG_UPDATE_PARENT;
527 if (ea_size)
528 *ea_size = ea_info.size;
529 mark_inode_dirty(&ni->vfs_inode);
530
531 out:
532 if (!locked)
533 ni_unlock(ni);
534
535 run_close(&ea_run);
536 kfree(ea_all);
537
538 return err;
539 }
540
541 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
542
543 /*
544 * ntfs_get_acl - inode_operations::get_acl
545 */
ntfs_get_acl(struct mnt_idmap * idmap,struct dentry * dentry,int type)546 struct posix_acl *ntfs_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
547 int type)
548 {
549 struct inode *inode = d_inode(dentry);
550 struct ntfs_inode *ni = ntfs_i(inode);
551 const char *name;
552 size_t name_len;
553 struct posix_acl *acl;
554 size_t req;
555 int err;
556 void *buf;
557
558 /* Avoid any operation if inode is bad. */
559 if (unlikely(is_bad_ni(ni)))
560 return ERR_PTR(-EINVAL);
561
562 buf = kmalloc(PATH_MAX, GFP_KERNEL);
563 if (!buf)
564 return ERR_PTR(-ENOMEM);
565
566 /* Possible values of 'type' was already checked above. */
567 if (type == ACL_TYPE_ACCESS) {
568 name = XATTR_NAME_POSIX_ACL_ACCESS;
569 name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
570 } else {
571 name = XATTR_NAME_POSIX_ACL_DEFAULT;
572 name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
573 }
574
575 ni_lock(ni);
576
577 err = ntfs_get_ea(inode, name, name_len, buf, PATH_MAX, &req);
578
579 ni_unlock(ni);
580
581 /* Translate extended attribute to acl. */
582 if (err >= 0) {
583 acl = posix_acl_from_xattr(&init_user_ns, buf, err);
584 } else if (err == -ENODATA) {
585 acl = NULL;
586 } else {
587 acl = ERR_PTR(err);
588 }
589
590 if (!IS_ERR(acl))
591 set_cached_acl(inode, type, acl);
592
593 kfree(buf);
594
595 return acl;
596 }
597
ntfs_set_acl_ex(struct mnt_idmap * idmap,struct inode * inode,struct posix_acl * acl,int type,bool init_acl)598 static noinline int ntfs_set_acl_ex(struct mnt_idmap *idmap,
599 struct inode *inode, struct posix_acl *acl,
600 int type, bool init_acl)
601 {
602 const char *name;
603 size_t size, name_len;
604 void *value;
605 int err;
606 int flags;
607 umode_t mode;
608
609 /* Avoid any operation if inode is bad. */
610 if (unlikely(is_bad_ni(ntfs_i(inode))))
611 return -EINVAL;
612
613 if (S_ISLNK(inode->i_mode))
614 return -EOPNOTSUPP;
615
616 mode = inode->i_mode;
617 switch (type) {
618 case ACL_TYPE_ACCESS:
619 /* Do not change i_mode if we are in init_acl */
620 if (acl && !init_acl) {
621 err = posix_acl_update_mode(idmap, inode, &mode, &acl);
622 if (err)
623 return err;
624 }
625 name = XATTR_NAME_POSIX_ACL_ACCESS;
626 name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
627 break;
628
629 case ACL_TYPE_DEFAULT:
630 if (!S_ISDIR(inode->i_mode))
631 return acl ? -EACCES : 0;
632 name = XATTR_NAME_POSIX_ACL_DEFAULT;
633 name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
634 break;
635
636 default:
637 return -EINVAL;
638 }
639
640 if (!acl) {
641 /* Remove xattr if it can be presented via mode. */
642 size = 0;
643 value = NULL;
644 flags = XATTR_REPLACE;
645 } else {
646 value = posix_acl_to_xattr(&init_user_ns, acl, &size, GFP_NOFS);
647 if (!value)
648 return -ENOMEM;
649 flags = 0;
650 }
651
652 err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0, NULL);
653 if (err == -ENODATA && !size)
654 err = 0; /* Removing non existed xattr. */
655 if (err)
656 goto out;
657
658 if (inode->i_mode != mode) {
659 umode_t old_mode = inode->i_mode;
660 inode->i_mode = mode;
661 err = ntfs_save_wsl_perm(inode, NULL);
662 if (err) {
663 inode->i_mode = old_mode;
664 goto out;
665 }
666 }
667 set_cached_acl(inode, type, acl);
668 inode_set_ctime_current(inode);
669 mark_inode_dirty(inode);
670
671 out:
672 kfree(value);
673
674 return err;
675 }
676
677 /*
678 * ntfs_set_acl - inode_operations::set_acl
679 */
ntfs_set_acl(struct mnt_idmap * idmap,struct dentry * dentry,struct posix_acl * acl,int type)680 int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
681 struct posix_acl *acl, int type)
682 {
683 return ntfs_set_acl_ex(idmap, d_inode(dentry), acl, type, false);
684 }
685
686 /*
687 * ntfs_init_acl - Initialize the ACLs of a new inode.
688 *
689 * Called from ntfs_create_inode().
690 */
ntfs_init_acl(struct mnt_idmap * idmap,struct inode * inode,struct inode * dir)691 int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
692 struct inode *dir)
693 {
694 struct posix_acl *default_acl, *acl;
695 int err;
696
697 err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
698 if (err)
699 return err;
700
701 if (default_acl) {
702 err = ntfs_set_acl_ex(idmap, inode, default_acl,
703 ACL_TYPE_DEFAULT, true);
704 posix_acl_release(default_acl);
705 } else {
706 inode->i_default_acl = NULL;
707 }
708
709 if (acl) {
710 if (!err)
711 err = ntfs_set_acl_ex(idmap, inode, acl,
712 ACL_TYPE_ACCESS, true);
713 posix_acl_release(acl);
714 } else {
715 inode->i_acl = NULL;
716 }
717
718 return err;
719 }
720 #endif
721
722 /*
723 * ntfs_acl_chmod - Helper for ntfs_setattr().
724 */
ntfs_acl_chmod(struct mnt_idmap * idmap,struct dentry * dentry)725 int ntfs_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry)
726 {
727 struct inode *inode = d_inode(dentry);
728 struct super_block *sb = inode->i_sb;
729
730 if (!(sb->s_flags & SB_POSIXACL))
731 return 0;
732
733 if (S_ISLNK(inode->i_mode))
734 return -EOPNOTSUPP;
735
736 return posix_acl_chmod(idmap, dentry, inode->i_mode);
737 }
738
739 /*
740 * ntfs_listxattr - inode_operations::listxattr
741 */
ntfs_listxattr(struct dentry * dentry,char * buffer,size_t size)742 ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
743 {
744 struct inode *inode = d_inode(dentry);
745 struct ntfs_inode *ni = ntfs_i(inode);
746 ssize_t ret;
747
748 /* Avoid any operation if inode is bad. */
749 if (unlikely(is_bad_ni(ni)))
750 return -EINVAL;
751
752 if (!(ni->ni_flags & NI_FLAG_EA)) {
753 /* no xattr in file */
754 return 0;
755 }
756
757 ni_lock(ni);
758
759 ret = ntfs_list_ea(ni, buffer, size);
760
761 ni_unlock(ni);
762
763 return ret;
764 }
765
ntfs_getxattr(const struct xattr_handler * handler,struct dentry * de,struct inode * inode,const char * name,void * buffer,size_t size)766 static int ntfs_getxattr(const struct xattr_handler *handler, struct dentry *de,
767 struct inode *inode, const char *name, void *buffer,
768 size_t size)
769 {
770 int err;
771 struct ntfs_inode *ni = ntfs_i(inode);
772
773 /* Avoid any operation if inode is bad. */
774 if (unlikely(is_bad_ni(ni)))
775 return -EINVAL;
776
777 if (unlikely(ntfs3_forced_shutdown(inode->i_sb)))
778 return -EIO;
779
780 /* Dispatch request. */
781 if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
782 /* system.dos_attrib */
783 if (!buffer) {
784 err = sizeof(u8);
785 } else if (size < sizeof(u8)) {
786 err = -ENODATA;
787 } else {
788 err = sizeof(u8);
789 *(u8 *)buffer = le32_to_cpu(ni->std_fa);
790 }
791 goto out;
792 }
793
794 if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
795 !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
796 /* system.ntfs_attrib */
797 if (!buffer) {
798 err = sizeof(u32);
799 } else if (size < sizeof(u32)) {
800 err = -ENODATA;
801 } else {
802 err = sizeof(u32);
803 *(u32 *)buffer = le32_to_cpu(ni->std_fa);
804 if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
805 *(__be32 *)buffer = cpu_to_be32(*(u32 *)buffer);
806 }
807 goto out;
808 }
809
810 if (!strcmp(name, SYSTEM_NTFS_SECURITY)) {
811 /* system.ntfs_security*/
812 struct SECURITY_DESCRIPTOR_RELATIVE *sd = NULL;
813 size_t sd_size = 0;
814
815 if (!is_ntfs3(ni->mi.sbi)) {
816 /* We should get nt4 security. */
817 err = -EINVAL;
818 goto out;
819 } else if (le32_to_cpu(ni->std_security_id) <
820 SECURITY_ID_FIRST) {
821 err = -ENOENT;
822 goto out;
823 }
824
825 err = ntfs_get_security_by_id(ni->mi.sbi, ni->std_security_id,
826 &sd, &sd_size);
827 if (err)
828 goto out;
829
830 if (!is_sd_valid(sd, sd_size)) {
831 ntfs_inode_warn(
832 inode,
833 "looks like you get incorrect security descriptor id=%u",
834 ni->std_security_id);
835 }
836
837 if (!buffer) {
838 err = sd_size;
839 } else if (size < sd_size) {
840 err = -ENODATA;
841 } else {
842 err = sd_size;
843 memcpy(buffer, sd, sd_size);
844 }
845 kfree(sd);
846 goto out;
847 }
848
849 /* Deal with NTFS extended attribute. */
850 err = ntfs_get_ea(inode, name, strlen(name), buffer, size, NULL);
851
852 out:
853 return err;
854 }
855
ntfs_is_reserved_lxattr(const char * name)856 static bool ntfs_is_reserved_lxattr(const char *name)
857 {
858 return !strcmp(name, "$LXUID") || !strcmp(name, "$LXGID") ||
859 !strcmp(name, "$LXMOD") || !strcmp(name, "$LXDEV");
860 }
861
862 /*
863 * ntfs_setxattr - inode_operations::setxattr
864 */
ntfs_setxattr(const struct xattr_handler * handler,struct mnt_idmap * idmap,struct dentry * de,struct inode * inode,const char * name,const void * value,size_t size,int flags)865 static noinline int ntfs_setxattr(const struct xattr_handler *handler,
866 struct mnt_idmap *idmap, struct dentry *de,
867 struct inode *inode, const char *name,
868 const void *value, size_t size, int flags)
869 {
870 int err = -EINVAL;
871 struct ntfs_inode *ni = ntfs_i(inode);
872 enum FILE_ATTRIBUTE new_fa;
873
874 /* Dispatch request. */
875 if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
876 if (sizeof(u8) != size)
877 goto out;
878 /* system.dos_attrib only covers the low DOS attribute byte. */
879 new_fa = (ni->std_fa & ~cpu_to_le32(0xff)) |
880 cpu_to_le32(*(u8 *)value);
881 goto set_new_fa;
882 }
883
884 if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
885 !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
886 if (size != sizeof(u32))
887 goto out;
888 if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
889 new_fa = cpu_to_le32(be32_to_cpu(*(__be32 *)value));
890 else
891 new_fa = cpu_to_le32(*(u32 *)value);
892
893 if (S_ISREG(inode->i_mode)) {
894 /* Process compressed/sparsed in special way. */
895 ni_lock(ni);
896 err = ni_new_attr_flags(ni, new_fa);
897 ni_unlock(ni);
898 if (err)
899 goto out;
900 }
901 set_new_fa:
902 /*
903 * Thanks Mark Harmstone:
904 * Keep directory bit consistency.
905 */
906 if (S_ISDIR(inode->i_mode))
907 new_fa |= FILE_ATTRIBUTE_DIRECTORY;
908 else
909 new_fa &= ~FILE_ATTRIBUTE_DIRECTORY;
910
911 if (ni->std_fa != new_fa) {
912 ni->std_fa = new_fa;
913 if (new_fa & FILE_ATTRIBUTE_READONLY)
914 inode->i_mode &= ~0222;
915 else
916 inode->i_mode |= 0222;
917 /* Std attribute always in primary record. */
918 ni->mi.dirty = true;
919 mark_inode_dirty(inode);
920 }
921 err = 0;
922
923 goto out;
924 }
925
926 if (!strcmp(name, SYSTEM_NTFS_SECURITY)) {
927 /* system.ntfs_security*/
928 __le32 security_id;
929 bool inserted;
930 struct ATTR_STD_INFO5 *std;
931
932 if (!is_ntfs3(ni->mi.sbi)) {
933 /*
934 * We should replace ATTR_SECURE.
935 * Skip this way cause it is nt4 feature.
936 */
937 err = -EINVAL;
938 goto out;
939 }
940
941 if (!is_sd_valid(value, size)) {
942 err = -EINVAL;
943 ntfs_inode_warn(
944 inode,
945 "you try to set invalid security descriptor");
946 goto out;
947 }
948
949 err = ntfs_insert_security(ni->mi.sbi, value, size,
950 &security_id, &inserted);
951 if (err)
952 goto out;
953
954 ni_lock(ni);
955 std = ni_std5(ni);
956 if (!std) {
957 err = -EINVAL;
958 } else if (std->security_id != security_id) {
959 std->security_id = ni->std_security_id = security_id;
960 /* Std attribute always in primary record. */
961 ni->mi.dirty = true;
962 mark_inode_dirty(&ni->vfs_inode);
963 }
964 ni_unlock(ni);
965 goto out;
966 }
967
968 /* Do not allow non privileged users to change $LXUID/$LXGID... */
969 if (ntfs_is_reserved_lxattr(name) && !capable(CAP_SYS_ADMIN)) {
970 err = -EPERM;
971 goto out;
972 }
973
974 /* Deal with NTFS extended attribute. */
975 err = ntfs_set_ea(inode, name, strlen(name), value, size, flags, 0,
976 NULL);
977
978 out:
979 inode_set_ctime_current(inode);
980 mark_inode_dirty(inode);
981
982 return err;
983 }
984
985 /*
986 * ntfs_save_wsl_perm
987 *
988 * save uid/gid/mode in xattr
989 */
ntfs_save_wsl_perm(struct inode * inode,__le32 * ea_size)990 int ntfs_save_wsl_perm(struct inode *inode, __le32 *ea_size)
991 {
992 int err;
993 __le32 value;
994 struct ntfs_inode *ni = ntfs_i(inode);
995
996 ni_lock(ni);
997 value = cpu_to_le32(i_uid_read(inode));
998 err = ntfs_set_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value,
999 sizeof(value), 0, true, ea_size);
1000 if (err)
1001 goto out;
1002
1003 value = cpu_to_le32(i_gid_read(inode));
1004 err = ntfs_set_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value,
1005 sizeof(value), 0, true, ea_size);
1006 if (err)
1007 goto out;
1008
1009 value = cpu_to_le32(inode->i_mode);
1010 err = ntfs_set_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value,
1011 sizeof(value), 0, true, ea_size);
1012 if (err)
1013 goto out;
1014
1015 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1016 value = cpu_to_le32(inode->i_rdev);
1017 err = ntfs_set_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &value,
1018 sizeof(value), 0, true, ea_size);
1019 if (err)
1020 goto out;
1021 }
1022
1023 out:
1024 ni_unlock(ni);
1025 /* In case of error should we delete all WSL xattr? */
1026 return err;
1027 }
1028
1029 /*
1030 * ntfs_get_wsl_perm
1031 *
1032 * get uid/gid/mode from xattr
1033 * it is called from ntfs_iget5->ntfs_read_mft
1034 */
ntfs_get_wsl_perm(struct inode * inode)1035 void ntfs_get_wsl_perm(struct inode *inode)
1036 {
1037 size_t sz;
1038 __le32 value[3];
1039
1040 if (ntfs_get_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value[0],
1041 sizeof(value[0]), &sz) == sizeof(value[0]) &&
1042 ntfs_get_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value[1],
1043 sizeof(value[1]), &sz) == sizeof(value[1]) &&
1044 ntfs_get_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value[2],
1045 sizeof(value[2]), &sz) == sizeof(value[2])) {
1046 i_uid_write(inode, (uid_t)le32_to_cpu(value[0]));
1047 i_gid_write(inode, (gid_t)le32_to_cpu(value[1]));
1048 inode->i_mode = le32_to_cpu(value[2]);
1049
1050 if (ntfs_get_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1,
1051 &value[0], sizeof(value),
1052 &sz) == sizeof(value[0])) {
1053 inode->i_rdev = le32_to_cpu(value[0]);
1054 }
1055 }
1056 }
1057
ntfs_xattr_user_list(struct dentry * dentry)1058 static bool ntfs_xattr_user_list(struct dentry *dentry)
1059 {
1060 return true;
1061 }
1062
1063 // clang-format off
1064 static const struct xattr_handler ntfs_other_xattr_handler = {
1065 .prefix = "",
1066 .get = ntfs_getxattr,
1067 .set = ntfs_setxattr,
1068 .list = ntfs_xattr_user_list,
1069 };
1070
1071 const struct xattr_handler * const ntfs_xattr_handlers[] = {
1072 &ntfs_other_xattr_handler,
1073 NULL,
1074 };
1075 // clang-format on
1076