xref: /linux/fs/ntfs3/xattr.c (revision a11b4fa602ed3b744aa075f34bee82c12aa3553a)
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 
150 		/* Check if we can use field ea->size. */
151 		if (bytes < sizeof(ef->size))
152 			goto out1;
153 
154 		if (ef->size) {
155 			ea_size = le32_to_cpu(ef->size);
156 			if (ea_size > bytes)
157 				goto out1;
158 			continue;
159 		}
160 
161 		/* Check if we can use fields ef->name_len and ef->elength. */
162 		if (bytes < offsetof(struct EA_FULL, name))
163 			goto out1;
164 
165 		ea_size = ALIGN(struct_size(ef, name,
166 					    1 + ef->name_len +
167 						    le16_to_cpu(ef->elength)),
168 				4);
169 		if (ea_size > bytes)
170 			goto out1;
171 	}
172 
173 	*ea = ea_p;
174 	return 0;
175 
176 out1:
177 	kfree(ea_p);
178 out:
179 	ntfs_set_state(sbi, NTFS_DIRTY_DIRTY);
180 	return err;
181 }
182 
183 /*
184  * ntfs_list_ea
185  *
186  * Copy a list of xattrs names into the buffer
187  * provided, or compute the buffer size required.
188  *
189  * Return:
190  * * Number of bytes used / required on
191  * * -ERRNO - on failure
192  */
ntfs_list_ea(struct ntfs_inode * ni,char * buffer,size_t bytes_per_buffer)193 static ssize_t ntfs_list_ea(struct ntfs_inode *ni, char *buffer,
194 			    size_t bytes_per_buffer)
195 {
196 	const struct EA_INFO *info;
197 	struct EA_FULL *ea_all = NULL;
198 	u32 off, size;
199 	int err;
200 	size_t ret;
201 
202 	err = ntfs_read_ea(ni, &ea_all, 0, &info);
203 	if (err)
204 		return err;
205 
206 	if (!info || !ea_all)
207 		return 0;
208 
209 	size = le32_to_cpu(info->size);
210 
211 	/* Enumerate all xattrs. */
212 	ret = 0;
213 	off = 0;
214 	while (off + sizeof(struct EA_FULL) < size) {
215 		const struct EA_FULL *ea = Add2Ptr(ea_all, off);
216 		int ea_size = unpacked_ea_size(ea);
217 		u8 name_len = ea->name_len;
218 
219 		if (!name_len)
220 			break;
221 
222 		if (name_len > ea_size) {
223 			ntfs_set_state(ni->mi.sbi, NTFS_DIRTY_ERROR);
224 			err = -EINVAL; /* corrupted fs. */
225 			break;
226 		}
227 
228 		if (buffer) {
229 			/* Check if we can use field ea->name */
230 			if (off + ea_size > size)
231 				break;
232 
233 			if (ret + name_len + 1 > bytes_per_buffer) {
234 				err = -ERANGE;
235 				goto out;
236 			}
237 
238 			memcpy(buffer + ret, ea->name, name_len);
239 			buffer[ret + name_len] = 0;
240 		}
241 
242 		ret += name_len + 1;
243 		off += ea_size;
244 	}
245 
246 out:
247 	kfree(ea_all);
248 	return err ? err : ret;
249 }
250 
ntfs_get_ea(struct inode * inode,const char * name,size_t name_len,void * buffer,size_t size,size_t * required)251 static int ntfs_get_ea(struct inode *inode, const char *name, size_t name_len,
252 		       void *buffer, size_t size, size_t *required)
253 {
254 	struct ntfs_inode *ni = ntfs_i(inode);
255 	const struct EA_INFO *info;
256 	struct EA_FULL *ea_all = NULL;
257 	const struct EA_FULL *ea;
258 	u32 off, len;
259 	int err;
260 
261 	if (!(ni->ni_flags & NI_FLAG_EA))
262 		return -ENODATA;
263 
264 	if (!required)
265 		ni_lock(ni);
266 
267 	len = 0;
268 
269 	if (name_len > 255) {
270 		err = -ENAMETOOLONG;
271 		goto out;
272 	}
273 
274 	err = ntfs_read_ea(ni, &ea_all, 0, &info);
275 	if (err)
276 		goto out;
277 
278 	if (!info)
279 		goto out;
280 
281 	/* Enumerate all xattrs. */
282 	if (!find_ea(ea_all, le32_to_cpu(info->size), name, name_len, &off,
283 		     NULL)) {
284 		err = -ENODATA;
285 		goto out;
286 	}
287 	ea = Add2Ptr(ea_all, off);
288 
289 	len = le16_to_cpu(ea->elength);
290 	if (!buffer) {
291 		err = 0;
292 		goto out;
293 	}
294 
295 	if (len > size) {
296 		err = -ERANGE;
297 		if (required)
298 			*required = len;
299 		goto out;
300 	}
301 
302 	memcpy(buffer, ea->name + ea->name_len + 1, len);
303 	err = 0;
304 
305 out:
306 	kfree(ea_all);
307 	if (!required)
308 		ni_unlock(ni);
309 
310 	return err ? err : len;
311 }
312 
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)313 static noinline int ntfs_set_ea(struct inode *inode, const char *name,
314 				size_t name_len, const void *value,
315 				size_t val_size, int flags, bool locked,
316 				__le32 *ea_size)
317 {
318 	struct ntfs_inode *ni = ntfs_i(inode);
319 	struct ntfs_sb_info *sbi = ni->mi.sbi;
320 	int err;
321 	struct EA_INFO ea_info;
322 	const struct EA_INFO *info;
323 	struct EA_FULL *new_ea;
324 	struct EA_FULL *ea_all = NULL;
325 	size_t add, new_pack;
326 	u32 off, size, ea_sz;
327 	__le16 size_pack;
328 	struct ATTRIB *attr;
329 	struct ATTR_LIST_ENTRY *le;
330 	struct mft_inode *mi;
331 	struct runs_tree ea_run;
332 	u64 new_sz;
333 	void *p;
334 
335 	if (!locked)
336 		ni_lock(ni);
337 
338 	run_init(&ea_run);
339 
340 	if (name_len > 255) {
341 		err = -ENAMETOOLONG;
342 		goto out;
343 	}
344 
345 	add = ALIGN(struct_size(ea_all, name, 1 + name_len + val_size), 4);
346 
347 	err = ntfs_read_ea(ni, &ea_all, add, &info);
348 	if (err)
349 		goto out;
350 
351 	if (!info) {
352 		memset(&ea_info, 0, sizeof(ea_info));
353 		size = 0;
354 		size_pack = 0;
355 	} else {
356 		memcpy(&ea_info, info, sizeof(ea_info));
357 		size = le32_to_cpu(ea_info.size);
358 		size_pack = ea_info.size_pack;
359 	}
360 
361 	if (info && find_ea(ea_all, size, name, name_len, &off, &ea_sz)) {
362 		struct EA_FULL *ea;
363 
364 		if (flags & XATTR_CREATE) {
365 			err = -EEXIST;
366 			goto out;
367 		}
368 
369 		ea = Add2Ptr(ea_all, off);
370 
371 		/*
372 		 * Check simple case when we try to insert xattr with the same value
373 		 * e.g. ntfs_save_wsl_perm
374 		 */
375 		if (val_size && le16_to_cpu(ea->elength) == val_size &&
376 		    !memcmp(ea->name + ea->name_len + 1, value, val_size)) {
377 			/* xattr already contains the required value. */
378 			goto out;
379 		}
380 
381 		/* Remove current xattr. */
382 		if (ea->flags & FILE_NEED_EA)
383 			le16_add_cpu(&ea_info.count, -1);
384 
385 		le16_add_cpu(&ea_info.size_pack, 0 - packed_ea_size(ea));
386 
387 		memmove(ea, Add2Ptr(ea, ea_sz), size - off - ea_sz);
388 
389 		size -= ea_sz;
390 		memset(Add2Ptr(ea_all, size), 0, ea_sz);
391 
392 		ea_info.size = cpu_to_le32(size);
393 
394 		if ((flags & XATTR_REPLACE) && !val_size) {
395 			/* Remove xattr. */
396 			goto update_ea;
397 		}
398 	} else {
399 		if (flags & XATTR_REPLACE) {
400 			err = -ENODATA;
401 			goto out;
402 		}
403 
404 		if (!ea_all) {
405 			ea_all = kzalloc(add, GFP_NOFS);
406 			if (!ea_all) {
407 				err = -ENOMEM;
408 				goto out;
409 			}
410 		}
411 	}
412 
413 	/* Append new xattr. */
414 	new_ea = Add2Ptr(ea_all, size);
415 	new_ea->size = cpu_to_le32(add);
416 	new_ea->flags = 0;
417 	new_ea->name_len = name_len;
418 	new_ea->elength = cpu_to_le16(val_size);
419 	memcpy(new_ea->name, name, name_len);
420 	new_ea->name[name_len] = 0;
421 	memcpy(new_ea->name + name_len + 1, value, val_size);
422 	new_pack = le16_to_cpu(ea_info.size_pack) + packed_ea_size(new_ea);
423 	ea_info.size_pack = cpu_to_le16(new_pack);
424 	/* New size of ATTR_EA. */
425 	size += add;
426 	ea_info.size = cpu_to_le32(size);
427 
428 	/*
429 	 * 1. Check ea_info.size_pack for overflow.
430 	 * 2. New attribute size must fit value from $AttrDef
431 	 */
432 	if (new_pack > 0xffff || size > sbi->ea_max_size) {
433 		ntfs_inode_warn(
434 			inode,
435 			"The size of extended attributes must not exceed 64KiB");
436 		err = -EFBIG; // -EINVAL?
437 		goto out;
438 	}
439 
440 update_ea:
441 
442 	if (!info) {
443 		/* Create xattr. */
444 		if (!size) {
445 			err = 0;
446 			goto out;
447 		}
448 
449 		err = ni_insert_resident(ni, sizeof(struct EA_INFO),
450 					 ATTR_EA_INFO, NULL, 0, NULL, NULL,
451 					 NULL);
452 		if (err)
453 			goto out;
454 
455 		err = ni_insert_resident(ni, 0, ATTR_EA, NULL, 0, NULL, NULL,
456 					 NULL);
457 		if (err)
458 			goto out;
459 	}
460 
461 	new_sz = size;
462 	err = attr_set_size(ni, ATTR_EA, NULL, 0, &ea_run, new_sz, &new_sz,
463 			    false, NULL);
464 	if (err)
465 		goto out;
466 
467 	le = NULL;
468 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, &mi);
469 	if (!attr) {
470 		err = -EINVAL;
471 		goto out;
472 	}
473 
474 	if (!size) {
475 		/* Delete xattr, ATTR_EA_INFO */
476 		ni_remove_attr_le(ni, attr, mi, le);
477 	} else {
478 		p = resident_data_ex(attr, sizeof(struct EA_INFO));
479 		if (!p) {
480 			err = -EINVAL;
481 			goto out;
482 		}
483 		memcpy(p, &ea_info, sizeof(struct EA_INFO));
484 		mi->dirty = true;
485 	}
486 
487 	le = NULL;
488 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA, NULL, 0, NULL, &mi);
489 	if (!attr) {
490 		err = -EINVAL;
491 		goto out;
492 	}
493 
494 	if (!size) {
495 		/* Delete xattr, ATTR_EA */
496 		ni_remove_attr_le(ni, attr, mi, le);
497 	} else if (attr->non_res) {
498 		err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &ea_run, 0,
499 					   size);
500 		if (err)
501 			goto out;
502 
503 		err = ntfs_sb_write_run(sbi, &ea_run, 0, ea_all, size, 0);
504 		if (err)
505 			goto out;
506 	} else {
507 		p = resident_data_ex(attr, size);
508 		if (!p) {
509 			err = -EINVAL;
510 			goto out;
511 		}
512 		memcpy(p, ea_all, size);
513 		mi->dirty = true;
514 	}
515 
516 	/* Check if we delete the last xattr. */
517 	if (size)
518 		ni->ni_flags |= NI_FLAG_EA;
519 	else
520 		ni->ni_flags &= ~NI_FLAG_EA;
521 
522 	if (ea_info.size_pack != size_pack)
523 		ni->ni_flags |= NI_FLAG_UPDATE_PARENT;
524 	if (ea_size)
525 		*ea_size = ea_info.size;
526 	mark_inode_dirty(&ni->vfs_inode);
527 
528 out:
529 	if (!locked)
530 		ni_unlock(ni);
531 
532 	run_close(&ea_run);
533 	kfree(ea_all);
534 
535 	return err;
536 }
537 
538 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
539 
540 /*
541  * ntfs_get_acl - inode_operations::get_acl
542  */
ntfs_get_acl(struct mnt_idmap * idmap,struct dentry * dentry,int type)543 struct posix_acl *ntfs_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
544 			       int type)
545 {
546 	struct inode *inode = d_inode(dentry);
547 	struct ntfs_inode *ni = ntfs_i(inode);
548 	const char *name;
549 	size_t name_len;
550 	struct posix_acl *acl;
551 	size_t req;
552 	int err;
553 	void *buf;
554 
555 	/* Avoid any operation if inode is bad. */
556 	if (unlikely(is_bad_ni(ni)))
557 		return ERR_PTR(-EINVAL);
558 
559 	/* Allocate PATH_MAX bytes. */
560 	buf = __getname();
561 	if (!buf)
562 		return ERR_PTR(-ENOMEM);
563 
564 	/* Possible values of 'type' was already checked above. */
565 	if (type == ACL_TYPE_ACCESS) {
566 		name = XATTR_NAME_POSIX_ACL_ACCESS;
567 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
568 	} else {
569 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
570 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
571 	}
572 
573 	ni_lock(ni);
574 
575 	err = ntfs_get_ea(inode, name, name_len, buf, PATH_MAX, &req);
576 
577 	ni_unlock(ni);
578 
579 	/* Translate extended attribute to acl. */
580 	if (err >= 0) {
581 		acl = posix_acl_from_xattr(&init_user_ns, buf, err);
582 	} else if (err == -ENODATA) {
583 		acl = NULL;
584 	} else {
585 		acl = ERR_PTR(err);
586 	}
587 
588 	if (!IS_ERR(acl))
589 		set_cached_acl(inode, type, acl);
590 
591 	__putname(buf);
592 
593 	return acl;
594 }
595 
ntfs_set_acl_ex(struct mnt_idmap * idmap,struct inode * inode,struct posix_acl * acl,int type,bool init_acl)596 static noinline int ntfs_set_acl_ex(struct mnt_idmap *idmap,
597 				    struct inode *inode, struct posix_acl *acl,
598 				    int type, bool init_acl)
599 {
600 	const char *name;
601 	size_t size, name_len;
602 	void *value;
603 	int err;
604 	int flags;
605 	umode_t mode;
606 
607 	/* Avoid any operation if inode is bad. */
608 	if (unlikely(is_bad_ni(ntfs_i(inode))))
609 		return -EINVAL;
610 
611 	if (S_ISLNK(inode->i_mode))
612 		return -EOPNOTSUPP;
613 
614 	mode = inode->i_mode;
615 	switch (type) {
616 	case ACL_TYPE_ACCESS:
617 		/* Do not change i_mode if we are in init_acl */
618 		if (acl && !init_acl) {
619 			err = posix_acl_update_mode(idmap, inode, &mode, &acl);
620 			if (err)
621 				return err;
622 		}
623 		name = XATTR_NAME_POSIX_ACL_ACCESS;
624 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
625 		break;
626 
627 	case ACL_TYPE_DEFAULT:
628 		if (!S_ISDIR(inode->i_mode))
629 			return acl ? -EACCES : 0;
630 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
631 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
632 		break;
633 
634 	default:
635 		return -EINVAL;
636 	}
637 
638 	if (!acl) {
639 		/* Remove xattr if it can be presented via mode. */
640 		size = 0;
641 		value = NULL;
642 		flags = XATTR_REPLACE;
643 	} else {
644 		size = posix_acl_xattr_size(acl->a_count);
645 		value = kmalloc(size, GFP_NOFS);
646 		if (!value)
647 			return -ENOMEM;
648 		err = posix_acl_to_xattr(&init_user_ns, acl, value, size);
649 		if (err < 0)
650 			goto out;
651 		flags = 0;
652 	}
653 
654 	err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0, NULL);
655 	if (err == -ENODATA && !size)
656 		err = 0; /* Removing non existed xattr. */
657 	if (!err) {
658 		set_cached_acl(inode, type, acl);
659 		inode->i_mode = mode;
660 		inode_set_ctime_current(inode);
661 		mark_inode_dirty(inode);
662 	}
663 
664 out:
665 	kfree(value);
666 
667 	return err;
668 }
669 
670 /*
671  * ntfs_set_acl - inode_operations::set_acl
672  */
ntfs_set_acl(struct mnt_idmap * idmap,struct dentry * dentry,struct posix_acl * acl,int type)673 int ntfs_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
674 		 struct posix_acl *acl, int type)
675 {
676 	return ntfs_set_acl_ex(idmap, d_inode(dentry), acl, type, false);
677 }
678 
679 /*
680  * ntfs_init_acl - Initialize the ACLs of a new inode.
681  *
682  * Called from ntfs_create_inode().
683  */
ntfs_init_acl(struct mnt_idmap * idmap,struct inode * inode,struct inode * dir)684 int ntfs_init_acl(struct mnt_idmap *idmap, struct inode *inode,
685 		  struct inode *dir)
686 {
687 	struct posix_acl *default_acl, *acl;
688 	int err;
689 
690 	err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
691 	if (err)
692 		return err;
693 
694 	if (default_acl) {
695 		err = ntfs_set_acl_ex(idmap, inode, default_acl,
696 				      ACL_TYPE_DEFAULT, true);
697 		posix_acl_release(default_acl);
698 	} else {
699 		inode->i_default_acl = NULL;
700 	}
701 
702 	if (acl) {
703 		if (!err)
704 			err = ntfs_set_acl_ex(idmap, inode, acl,
705 					      ACL_TYPE_ACCESS, true);
706 		posix_acl_release(acl);
707 	} else {
708 		inode->i_acl = NULL;
709 	}
710 
711 	return err;
712 }
713 #endif
714 
715 /*
716  * ntfs_acl_chmod - Helper for ntfs_setattr().
717  */
ntfs_acl_chmod(struct mnt_idmap * idmap,struct dentry * dentry)718 int ntfs_acl_chmod(struct mnt_idmap *idmap, struct dentry *dentry)
719 {
720 	struct inode *inode = d_inode(dentry);
721 	struct super_block *sb = inode->i_sb;
722 
723 	if (!(sb->s_flags & SB_POSIXACL))
724 		return 0;
725 
726 	if (S_ISLNK(inode->i_mode))
727 		return -EOPNOTSUPP;
728 
729 	return posix_acl_chmod(idmap, dentry, inode->i_mode);
730 }
731 
732 /*
733  * ntfs_listxattr - inode_operations::listxattr
734  */
ntfs_listxattr(struct dentry * dentry,char * buffer,size_t size)735 ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
736 {
737 	struct inode *inode = d_inode(dentry);
738 	struct ntfs_inode *ni = ntfs_i(inode);
739 	ssize_t ret;
740 
741 	/* Avoid any operation if inode is bad. */
742 	if (unlikely(is_bad_ni(ni)))
743 		return -EINVAL;
744 
745 	if (!(ni->ni_flags & NI_FLAG_EA)) {
746 		/* no xattr in file */
747 		return 0;
748 	}
749 
750 	ni_lock(ni);
751 
752 	ret = ntfs_list_ea(ni, buffer, size);
753 
754 	ni_unlock(ni);
755 
756 	return ret;
757 }
758 
ntfs_getxattr(const struct xattr_handler * handler,struct dentry * de,struct inode * inode,const char * name,void * buffer,size_t size)759 static int ntfs_getxattr(const struct xattr_handler *handler, struct dentry *de,
760 			 struct inode *inode, const char *name, void *buffer,
761 			 size_t size)
762 {
763 	int err;
764 	struct ntfs_inode *ni = ntfs_i(inode);
765 
766 	/* Avoid any operation if inode is bad. */
767 	if (unlikely(is_bad_ni(ni)))
768 		return -EINVAL;
769 
770 	if (unlikely(ntfs3_forced_shutdown(inode->i_sb)))
771 		return -EIO;
772 
773 	/* Dispatch request. */
774 	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
775 		/* system.dos_attrib */
776 		if (!buffer) {
777 			err = sizeof(u8);
778 		} else if (size < sizeof(u8)) {
779 			err = -ENODATA;
780 		} else {
781 			err = sizeof(u8);
782 			*(u8 *)buffer = le32_to_cpu(ni->std_fa);
783 		}
784 		goto out;
785 	}
786 
787 	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
788 	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
789 		/* system.ntfs_attrib */
790 		if (!buffer) {
791 			err = sizeof(u32);
792 		} else if (size < sizeof(u32)) {
793 			err = -ENODATA;
794 		} else {
795 			err = sizeof(u32);
796 			*(u32 *)buffer = le32_to_cpu(ni->std_fa);
797 			if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
798 				*(__be32 *)buffer = cpu_to_be32(*(u32 *)buffer);
799 		}
800 		goto out;
801 	}
802 
803 	if (!strcmp(name, SYSTEM_NTFS_SECURITY)) {
804 		/* system.ntfs_security*/
805 		struct SECURITY_DESCRIPTOR_RELATIVE *sd = NULL;
806 		size_t sd_size = 0;
807 
808 		if (!is_ntfs3(ni->mi.sbi)) {
809 			/* We should get nt4 security. */
810 			err = -EINVAL;
811 			goto out;
812 		} else if (le32_to_cpu(ni->std_security_id) <
813 			   SECURITY_ID_FIRST) {
814 			err = -ENOENT;
815 			goto out;
816 		}
817 
818 		err = ntfs_get_security_by_id(ni->mi.sbi, ni->std_security_id,
819 					      &sd, &sd_size);
820 		if (err)
821 			goto out;
822 
823 		if (!is_sd_valid(sd, sd_size)) {
824 			ntfs_inode_warn(
825 				inode,
826 				"looks like you get incorrect security descriptor id=%u",
827 				ni->std_security_id);
828 		}
829 
830 		if (!buffer) {
831 			err = sd_size;
832 		} else if (size < sd_size) {
833 			err = -ENODATA;
834 		} else {
835 			err = sd_size;
836 			memcpy(buffer, sd, sd_size);
837 		}
838 		kfree(sd);
839 		goto out;
840 	}
841 
842 	/* Deal with NTFS extended attribute. */
843 	err = ntfs_get_ea(inode, name, strlen(name), buffer, size, NULL);
844 
845 out:
846 	return err;
847 }
848 
849 /*
850  * ntfs_setxattr - inode_operations::setxattr
851  */
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)852 static noinline int ntfs_setxattr(const struct xattr_handler *handler,
853 				  struct mnt_idmap *idmap, struct dentry *de,
854 				  struct inode *inode, const char *name,
855 				  const void *value, size_t size, int flags)
856 {
857 	int err = -EINVAL;
858 	struct ntfs_inode *ni = ntfs_i(inode);
859 	enum FILE_ATTRIBUTE new_fa;
860 
861 	/* Dispatch request. */
862 	if (!strcmp(name, SYSTEM_DOS_ATTRIB)) {
863 		if (sizeof(u8) != size)
864 			goto out;
865 		new_fa = cpu_to_le32(*(u8 *)value);
866 		goto set_new_fa;
867 	}
868 
869 	if (!strcmp(name, SYSTEM_NTFS_ATTRIB) ||
870 	    !strcmp(name, SYSTEM_NTFS_ATTRIB_BE)) {
871 		if (size != sizeof(u32))
872 			goto out;
873 		if (!strcmp(name, SYSTEM_NTFS_ATTRIB_BE))
874 			new_fa = cpu_to_le32(be32_to_cpu(*(__be32 *)value));
875 		else
876 			new_fa = cpu_to_le32(*(u32 *)value);
877 
878 		if (S_ISREG(inode->i_mode)) {
879 			/* Process compressed/sparsed in special way. */
880 			ni_lock(ni);
881 			err = ni_new_attr_flags(ni, new_fa);
882 			ni_unlock(ni);
883 			if (err)
884 				goto out;
885 		}
886 set_new_fa:
887 		/*
888 		 * Thanks Mark Harmstone:
889 		 * Keep directory bit consistency.
890 		 */
891 		if (S_ISDIR(inode->i_mode))
892 			new_fa |= FILE_ATTRIBUTE_DIRECTORY;
893 		else
894 			new_fa &= ~FILE_ATTRIBUTE_DIRECTORY;
895 
896 		if (ni->std_fa != new_fa) {
897 			ni->std_fa = new_fa;
898 			if (new_fa & FILE_ATTRIBUTE_READONLY)
899 				inode->i_mode &= ~0222;
900 			else
901 				inode->i_mode |= 0222;
902 			/* Std attribute always in primary record. */
903 			ni->mi.dirty = true;
904 			mark_inode_dirty(inode);
905 		}
906 		err = 0;
907 
908 		goto out;
909 	}
910 
911 	if (!strcmp(name, SYSTEM_NTFS_SECURITY)) {
912 		/* system.ntfs_security*/
913 		__le32 security_id;
914 		bool inserted;
915 		struct ATTR_STD_INFO5 *std;
916 
917 		if (!is_ntfs3(ni->mi.sbi)) {
918 			/*
919 			 * We should replace ATTR_SECURE.
920 			 * Skip this way cause it is nt4 feature.
921 			 */
922 			err = -EINVAL;
923 			goto out;
924 		}
925 
926 		if (!is_sd_valid(value, size)) {
927 			err = -EINVAL;
928 			ntfs_inode_warn(
929 				inode,
930 				"you try to set invalid security descriptor");
931 			goto out;
932 		}
933 
934 		err = ntfs_insert_security(ni->mi.sbi, value, size,
935 					   &security_id, &inserted);
936 		if (err)
937 			goto out;
938 
939 		ni_lock(ni);
940 		std = ni_std5(ni);
941 		if (!std) {
942 			err = -EINVAL;
943 		} else if (std->security_id != security_id) {
944 			std->security_id = ni->std_security_id = security_id;
945 			/* Std attribute always in primary record. */
946 			ni->mi.dirty = true;
947 			mark_inode_dirty(&ni->vfs_inode);
948 		}
949 		ni_unlock(ni);
950 		goto out;
951 	}
952 
953 	/* Deal with NTFS extended attribute. */
954 	err = ntfs_set_ea(inode, name, strlen(name), value, size, flags, 0,
955 			  NULL);
956 
957 out:
958 	inode_set_ctime_current(inode);
959 	mark_inode_dirty(inode);
960 
961 	return err;
962 }
963 
964 /*
965  * ntfs_save_wsl_perm
966  *
967  * save uid/gid/mode in xattr
968  */
ntfs_save_wsl_perm(struct inode * inode,__le32 * ea_size)969 int ntfs_save_wsl_perm(struct inode *inode, __le32 *ea_size)
970 {
971 	int err;
972 	__le32 value;
973 	struct ntfs_inode *ni = ntfs_i(inode);
974 
975 	ni_lock(ni);
976 	value = cpu_to_le32(i_uid_read(inode));
977 	err = ntfs_set_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value,
978 			  sizeof(value), 0, true, ea_size);
979 	if (err)
980 		goto out;
981 
982 	value = cpu_to_le32(i_gid_read(inode));
983 	err = ntfs_set_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value,
984 			  sizeof(value), 0, true, ea_size);
985 	if (err)
986 		goto out;
987 
988 	value = cpu_to_le32(inode->i_mode);
989 	err = ntfs_set_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value,
990 			  sizeof(value), 0, true, ea_size);
991 	if (err)
992 		goto out;
993 
994 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
995 		value = cpu_to_le32(inode->i_rdev);
996 		err = ntfs_set_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &value,
997 				  sizeof(value), 0, true, ea_size);
998 		if (err)
999 			goto out;
1000 	}
1001 
1002 out:
1003 	ni_unlock(ni);
1004 	/* In case of error should we delete all WSL xattr? */
1005 	return err;
1006 }
1007 
1008 /*
1009  * ntfs_get_wsl_perm
1010  *
1011  * get uid/gid/mode from xattr
1012  * it is called from ntfs_iget5->ntfs_read_mft
1013  */
ntfs_get_wsl_perm(struct inode * inode)1014 void ntfs_get_wsl_perm(struct inode *inode)
1015 {
1016 	size_t sz;
1017 	__le32 value[3];
1018 
1019 	if (ntfs_get_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value[0],
1020 			sizeof(value[0]), &sz) == sizeof(value[0]) &&
1021 	    ntfs_get_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value[1],
1022 			sizeof(value[1]), &sz) == sizeof(value[1]) &&
1023 	    ntfs_get_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value[2],
1024 			sizeof(value[2]), &sz) == sizeof(value[2])) {
1025 		i_uid_write(inode, (uid_t)le32_to_cpu(value[0]));
1026 		i_gid_write(inode, (gid_t)le32_to_cpu(value[1]));
1027 		inode->i_mode = le32_to_cpu(value[2]);
1028 
1029 		if (ntfs_get_ea(inode, "$LXDEV", sizeof("$$LXDEV") - 1,
1030 				&value[0], sizeof(value),
1031 				&sz) == sizeof(value[0])) {
1032 			inode->i_rdev = le32_to_cpu(value[0]);
1033 		}
1034 	}
1035 }
1036 
ntfs_xattr_user_list(struct dentry * dentry)1037 static bool ntfs_xattr_user_list(struct dentry *dentry)
1038 {
1039 	return true;
1040 }
1041 
1042 // clang-format off
1043 static const struct xattr_handler ntfs_other_xattr_handler = {
1044 	.prefix	= "",
1045 	.get	= ntfs_getxattr,
1046 	.set	= ntfs_setxattr,
1047 	.list	= ntfs_xattr_user_list,
1048 };
1049 
1050 const struct xattr_handler * const ntfs_xattr_handlers[] = {
1051 	&ntfs_other_xattr_handler,
1052 	NULL,
1053 };
1054 // clang-format on
1055