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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 
unpacked_ea_size(const struct EA_FULL * ea)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 
packed_ea_size(const struct EA_FULL * ea)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  */
find_ea(const struct EA_FULL * ea_all,u32 bytes,const char * name,u8 name_len,u32 * off,u32 * ea_sz)44 static inline bool find_ea(const struct EA_FULL *ea_all, u32 bytes,
45 			   const char *name, u8 name_len, u32 *off, u32 *ea_sz)
46 {
47 	u32 ea_size;
48 
49 	*off = 0;
50 	if (!ea_all)
51 		return false;
52 
53 	for (; *off < bytes; *off += ea_size) {
54 		const struct EA_FULL *ea = Add2Ptr(ea_all, *off);
55 		ea_size = unpacked_ea_size(ea);
56 		if (ea->name_len == name_len &&
57 		    !memcmp(ea->name, name, name_len)) {
58 			if (ea_sz)
59 				*ea_sz = ea_size;
60 			return true;
61 		}
62 	}
63 
64 	return false;
65 }
66 
67 /*
68  * ntfs_read_ea - Read all extended attributes.
69  * @ea:		New allocated memory.
70  * @info:	Pointer into resident data.
71  */
ntfs_read_ea(struct ntfs_inode * ni,struct EA_FULL ** ea,size_t add_bytes,const struct EA_INFO ** info)72 static int ntfs_read_ea(struct ntfs_inode *ni, struct EA_FULL **ea,
73 			size_t add_bytes, const struct EA_INFO **info)
74 {
75 	int err = -EINVAL;
76 	struct ntfs_sb_info *sbi = ni->mi.sbi;
77 	struct ATTR_LIST_ENTRY *le = NULL;
78 	struct ATTRIB *attr_info, *attr_ea;
79 	void *ea_p;
80 	u32 size, off, ea_size;
81 
82 	static_assert(le32_to_cpu(ATTR_EA_INFO) < le32_to_cpu(ATTR_EA));
83 
84 	*ea = NULL;
85 	*info = NULL;
86 
87 	attr_info =
88 		ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, NULL);
89 	attr_ea =
90 		ni_find_attr(ni, attr_info, &le, ATTR_EA, NULL, 0, NULL, NULL);
91 
92 	if (!attr_ea || !attr_info)
93 		return 0;
94 
95 	*info = resident_data_ex(attr_info, sizeof(struct EA_INFO));
96 	if (!*info)
97 		goto out;
98 
99 	/* Check Ea limit. */
100 	size = le32_to_cpu((*info)->size);
101 	if (size > sbi->ea_max_size) {
102 		err = -EFBIG;
103 		goto out;
104 	}
105 
106 	if (attr_size(attr_ea) > sbi->ea_max_size) {
107 		err = -EFBIG;
108 		goto out;
109 	}
110 
111 	if (!size) {
112 		/* EA info persists, but xattr is empty. Looks like EA problem. */
113 		goto out;
114 	}
115 
116 	/* Allocate memory for packed Ea. */
117 	ea_p = kmalloc(size_add(size, add_bytes), GFP_NOFS);
118 	if (!ea_p)
119 		return -ENOMEM;
120 
121 	if (attr_ea->non_res) {
122 		struct runs_tree run;
123 
124 		run_init(&run);
125 
126 		err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &run, 0, size);
127 		if (!err)
128 			err = ntfs_read_run_nb(sbi, &run, 0, ea_p, size, NULL);
129 		run_close(&run);
130 
131 		if (err)
132 			goto out1;
133 	} else {
134 		void *p = resident_data_ex(attr_ea, size);
135 
136 		if (!p)
137 			goto out1;
138 		memcpy(ea_p, p, size);
139 	}
140 
141 	memset(Add2Ptr(ea_p, size), 0, add_bytes);
142 
143 	/* Check all attributes for consistency. */
144 	for (off = 0; off < size; off += ea_size) {
145 		const struct EA_FULL *ef = Add2Ptr(ea_p, off);
146 		u32 bytes = size - off;
147 
148 		/* Check if we can use field ea->size. */
149 		if (bytes < sizeof(ef->size))
150 			goto out1;
151 
152 		if (ef->size) {
153 			ea_size = le32_to_cpu(ef->size);
154 			if (ea_size > bytes)
155 				goto out1;
156 			continue;
157 		}
158 
159 		/* Check if we can use fields ef->name_len and ef->elength. */
160 		if (bytes < offsetof(struct EA_FULL, name))
161 			goto out1;
162 
163 		ea_size = ALIGN(struct_size(ef, name,
164 					    1 + ef->name_len +
165 						    le16_to_cpu(ef->elength)),
166 				4);
167 		if (ea_size > bytes)
168 			goto out1;
169 	}
170 
171 	*ea = ea_p;
172 	return 0;
173 
174 out1:
175 	kfree(ea_p);
176 out:
177 	ntfs_set_state(sbi, NTFS_DIRTY_DIRTY);
178 	return err;
179 }
180 
181 /*
182  * ntfs_list_ea
183  *
184  * Copy a list of xattrs names into the buffer
185  * provided, or compute the buffer size required.
186  *
187  * Return:
188  * * Number of bytes used / required on
189  * * -ERRNO - on failure
190  */
ntfs_list_ea(struct ntfs_inode * ni,char * buffer,size_t bytes_per_buffer)191 static ssize_t ntfs_list_ea(struct ntfs_inode *ni, char *buffer,
192 			    size_t bytes_per_buffer)
193 {
194 	const struct EA_INFO *info;
195 	struct EA_FULL *ea_all = NULL;
196 	const struct EA_FULL *ea;
197 	u32 off, size;
198 	int err;
199 	int ea_size;
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 	for (off = 0; off + sizeof(struct EA_FULL) < size; off += ea_size) {
214 		ea = Add2Ptr(ea_all, off);
215 		ea_size = unpacked_ea_size(ea);
216 
217 		if (!ea->name_len)
218 			break;
219 
220 		if (ea->name_len > ea_size)
221 			break;
222 
223 		if (buffer) {
224 			/* Check if we can use field ea->name */
225 			if (off + ea_size > size)
226 				break;
227 
228 			if (ret + ea->name_len + 1 > bytes_per_buffer) {
229 				err = -ERANGE;
230 				goto out;
231 			}
232 
233 			memcpy(buffer + ret, ea->name, ea->name_len);
234 			buffer[ret + ea->name_len] = 0;
235 		}
236 
237 		ret += ea->name_len + 1;
238 	}
239 
240 out:
241 	kfree(ea_all);
242 	return err ? err : ret;
243 }
244 
ntfs_get_ea(struct inode * inode,const char * name,size_t name_len,void * buffer,size_t size,size_t * required)245 static int ntfs_get_ea(struct inode *inode, const char *name, size_t name_len,
246 		       void *buffer, size_t size, size_t *required)
247 {
248 	struct ntfs_inode *ni = ntfs_i(inode);
249 	const struct EA_INFO *info;
250 	struct EA_FULL *ea_all = NULL;
251 	const struct EA_FULL *ea;
252 	u32 off, len;
253 	int err;
254 
255 	if (!(ni->ni_flags & NI_FLAG_EA))
256 		return -ENODATA;
257 
258 	if (!required)
259 		ni_lock(ni);
260 
261 	len = 0;
262 
263 	if (name_len > 255) {
264 		err = -ENAMETOOLONG;
265 		goto out;
266 	}
267 
268 	err = ntfs_read_ea(ni, &ea_all, 0, &info);
269 	if (err)
270 		goto out;
271 
272 	if (!info)
273 		goto out;
274 
275 	/* Enumerate all xattrs. */
276 	if (!find_ea(ea_all, le32_to_cpu(info->size), name, name_len, &off,
277 		     NULL)) {
278 		err = -ENODATA;
279 		goto out;
280 	}
281 	ea = Add2Ptr(ea_all, off);
282 
283 	len = le16_to_cpu(ea->elength);
284 	if (!buffer) {
285 		err = 0;
286 		goto out;
287 	}
288 
289 	if (len > size) {
290 		err = -ERANGE;
291 		if (required)
292 			*required = len;
293 		goto out;
294 	}
295 
296 	memcpy(buffer, ea->name + ea->name_len + 1, len);
297 	err = 0;
298 
299 out:
300 	kfree(ea_all);
301 	if (!required)
302 		ni_unlock(ni);
303 
304 	return err ? err : len;
305 }
306 
ntfs_set_ea(struct inode * inode,const char * name,size_t name_len,const void * value,size_t val_size,int flags,bool locked)307 static noinline int ntfs_set_ea(struct inode *inode, const char *name,
308 				size_t name_len, const void *value,
309 				size_t val_size, int flags, bool locked)
310 {
311 	struct ntfs_inode *ni = ntfs_i(inode);
312 	struct ntfs_sb_info *sbi = ni->mi.sbi;
313 	int err;
314 	struct EA_INFO ea_info;
315 	const struct EA_INFO *info;
316 	struct EA_FULL *new_ea;
317 	struct EA_FULL *ea_all = NULL;
318 	size_t add, new_pack;
319 	u32 off, size, ea_sz;
320 	__le16 size_pack;
321 	struct ATTRIB *attr;
322 	struct ATTR_LIST_ENTRY *le;
323 	struct mft_inode *mi;
324 	struct runs_tree ea_run;
325 	u64 new_sz;
326 	void *p;
327 
328 	if (!locked)
329 		ni_lock(ni);
330 
331 	run_init(&ea_run);
332 
333 	if (name_len > 255) {
334 		err = -ENAMETOOLONG;
335 		goto out;
336 	}
337 
338 	add = ALIGN(struct_size(ea_all, name, 1 + name_len + val_size), 4);
339 
340 	err = ntfs_read_ea(ni, &ea_all, add, &info);
341 	if (err)
342 		goto out;
343 
344 	if (!info) {
345 		memset(&ea_info, 0, sizeof(ea_info));
346 		size = 0;
347 		size_pack = 0;
348 	} else {
349 		memcpy(&ea_info, info, sizeof(ea_info));
350 		size = le32_to_cpu(ea_info.size);
351 		size_pack = ea_info.size_pack;
352 	}
353 
354 	if (info && find_ea(ea_all, size, name, name_len, &off, &ea_sz)) {
355 		struct EA_FULL *ea;
356 
357 		if (flags & XATTR_CREATE) {
358 			err = -EEXIST;
359 			goto out;
360 		}
361 
362 		ea = Add2Ptr(ea_all, off);
363 
364 		/*
365 		 * Check simple case when we try to insert xattr with the same value
366 		 * e.g. ntfs_save_wsl_perm
367 		 */
368 		if (val_size && le16_to_cpu(ea->elength) == val_size &&
369 		    !memcmp(ea->name + ea->name_len + 1, value, val_size)) {
370 			/* xattr already contains the required value. */
371 			goto out;
372 		}
373 
374 		/* Remove current xattr. */
375 		if (ea->flags & FILE_NEED_EA)
376 			le16_add_cpu(&ea_info.count, -1);
377 
378 		le16_add_cpu(&ea_info.size_pack, 0 - packed_ea_size(ea));
379 
380 		memmove(ea, Add2Ptr(ea, ea_sz), size - off - ea_sz);
381 
382 		size -= ea_sz;
383 		memset(Add2Ptr(ea_all, size), 0, ea_sz);
384 
385 		ea_info.size = cpu_to_le32(size);
386 
387 		if ((flags & XATTR_REPLACE) && !val_size) {
388 			/* Remove xattr. */
389 			goto update_ea;
390 		}
391 	} else {
392 		if (flags & XATTR_REPLACE) {
393 			err = -ENODATA;
394 			goto out;
395 		}
396 
397 		if (!ea_all) {
398 			ea_all = kzalloc(add, GFP_NOFS);
399 			if (!ea_all) {
400 				err = -ENOMEM;
401 				goto out;
402 			}
403 		}
404 	}
405 
406 	/* Append new xattr. */
407 	new_ea = Add2Ptr(ea_all, size);
408 	new_ea->size = cpu_to_le32(add);
409 	new_ea->flags = 0;
410 	new_ea->name_len = name_len;
411 	new_ea->elength = cpu_to_le16(val_size);
412 	memcpy(new_ea->name, name, name_len);
413 	new_ea->name[name_len] = 0;
414 	memcpy(new_ea->name + name_len + 1, value, val_size);
415 	new_pack = le16_to_cpu(ea_info.size_pack) + packed_ea_size(new_ea);
416 	ea_info.size_pack = cpu_to_le16(new_pack);
417 	/* New size of ATTR_EA. */
418 	size += add;
419 	ea_info.size = cpu_to_le32(size);
420 
421 	/*
422 	 * 1. Check ea_info.size_pack for overflow.
423 	 * 2. New attibute size must fit value from $AttrDef
424 	 */
425 	if (new_pack > 0xffff || size > sbi->ea_max_size) {
426 		ntfs_inode_warn(
427 			inode,
428 			"The size of extended attributes must not exceed 64KiB");
429 		err = -EFBIG; // -EINVAL?
430 		goto out;
431 	}
432 
433 update_ea:
434 
435 	if (!info) {
436 		/* Create xattr. */
437 		if (!size) {
438 			err = 0;
439 			goto out;
440 		}
441 
442 		err = ni_insert_resident(ni, sizeof(struct EA_INFO),
443 					 ATTR_EA_INFO, NULL, 0, NULL, NULL,
444 					 NULL);
445 		if (err)
446 			goto out;
447 
448 		err = ni_insert_resident(ni, 0, ATTR_EA, NULL, 0, NULL, NULL,
449 					 NULL);
450 		if (err)
451 			goto out;
452 	}
453 
454 	new_sz = size;
455 	err = attr_set_size(ni, ATTR_EA, NULL, 0, &ea_run, new_sz, &new_sz,
456 			    false, NULL);
457 	if (err)
458 		goto out;
459 
460 	le = NULL;
461 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, &mi);
462 	if (!attr) {
463 		err = -EINVAL;
464 		goto out;
465 	}
466 
467 	if (!size) {
468 		/* Delete xattr, ATTR_EA_INFO */
469 		ni_remove_attr_le(ni, attr, mi, le);
470 	} else {
471 		p = resident_data_ex(attr, sizeof(struct EA_INFO));
472 		if (!p) {
473 			err = -EINVAL;
474 			goto out;
475 		}
476 		memcpy(p, &ea_info, sizeof(struct EA_INFO));
477 		mi->dirty = true;
478 	}
479 
480 	le = NULL;
481 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA, NULL, 0, NULL, &mi);
482 	if (!attr) {
483 		err = -EINVAL;
484 		goto out;
485 	}
486 
487 	if (!size) {
488 		/* Delete xattr, ATTR_EA */
489 		ni_remove_attr_le(ni, attr, mi, le);
490 	} else if (attr->non_res) {
491 		err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &ea_run, 0,
492 					   size);
493 		if (err)
494 			goto out;
495 
496 		err = ntfs_sb_write_run(sbi, &ea_run, 0, ea_all, size, 0);
497 		if (err)
498 			goto out;
499 	} else {
500 		p = resident_data_ex(attr, size);
501 		if (!p) {
502 			err = -EINVAL;
503 			goto out;
504 		}
505 		memcpy(p, ea_all, size);
506 		mi->dirty = true;
507 	}
508 
509 	/* Check if we delete the last xattr. */
510 	if (size)
511 		ni->ni_flags |= NI_FLAG_EA;
512 	else
513 		ni->ni_flags &= ~NI_FLAG_EA;
514 
515 	if (ea_info.size_pack != size_pack)
516 		ni->ni_flags |= NI_FLAG_UPDATE_PARENT;
517 	mark_inode_dirty(&ni->vfs_inode);
518 
519 out:
520 	if (!locked)
521 		ni_unlock(ni);
522 
523 	run_close(&ea_run);
524 	kfree(ea_all);
525 
526 	return err;
527 }
528 
529 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
ntfs_get_acl_ex(struct inode * inode,int type,int locked)530 static struct posix_acl *ntfs_get_acl_ex(struct inode *inode, int type,
531 					 int locked)
532 {
533 	struct ntfs_inode *ni = ntfs_i(inode);
534 	const char *name;
535 	size_t name_len;
536 	struct posix_acl *acl;
537 	size_t req;
538 	int err;
539 	void *buf;
540 
541 	/* Allocate PATH_MAX bytes. */
542 	buf = __getname();
543 	if (!buf)
544 		return ERR_PTR(-ENOMEM);
545 
546 	/* Possible values of 'type' was already checked above. */
547 	if (type == ACL_TYPE_ACCESS) {
548 		name = XATTR_NAME_POSIX_ACL_ACCESS;
549 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
550 	} else {
551 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
552 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
553 	}
554 
555 	if (!locked)
556 		ni_lock(ni);
557 
558 	err = ntfs_get_ea(inode, name, name_len, buf, PATH_MAX, &req);
559 
560 	if (!locked)
561 		ni_unlock(ni);
562 
563 	/* Translate extended attribute to acl. */
564 	if (err >= 0) {
565 		acl = posix_acl_from_xattr(&init_user_ns, buf, err);
566 	} else if (err == -ENODATA) {
567 		acl = NULL;
568 	} else {
569 		acl = ERR_PTR(err);
570 	}
571 
572 	if (!IS_ERR(acl))
573 		set_cached_acl(inode, type, acl);
574 
575 	__putname(buf);
576 
577 	return acl;
578 }
579 
580 /*
581  * ntfs_get_acl - inode_operations::get_acl
582  */
ntfs_get_acl(struct inode * inode,int type,bool rcu)583 struct posix_acl *ntfs_get_acl(struct inode *inode, int type, bool rcu)
584 {
585 	if (rcu)
586 		return ERR_PTR(-ECHILD);
587 
588 	return ntfs_get_acl_ex(inode, type, 0);
589 }
590 
ntfs_set_acl_ex(struct user_namespace * mnt_userns,struct inode * inode,struct posix_acl * acl,int type,bool init_acl)591 static noinline int ntfs_set_acl_ex(struct user_namespace *mnt_userns,
592 				    struct inode *inode, struct posix_acl *acl,
593 				    int type, bool init_acl)
594 {
595 	const char *name;
596 	size_t size, name_len;
597 	void *value;
598 	int err;
599 	int flags;
600 	umode_t mode;
601 
602 	if (S_ISLNK(inode->i_mode))
603 		return -EOPNOTSUPP;
604 
605 	mode = inode->i_mode;
606 	switch (type) {
607 	case ACL_TYPE_ACCESS:
608 		/* Do not change i_mode if we are in init_acl */
609 		if (acl && !init_acl) {
610 			err = posix_acl_update_mode(mnt_userns, inode, &mode,
611 						    &acl);
612 			if (err)
613 				return err;
614 		}
615 		name = XATTR_NAME_POSIX_ACL_ACCESS;
616 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
617 		break;
618 
619 	case ACL_TYPE_DEFAULT:
620 		if (!S_ISDIR(inode->i_mode))
621 			return acl ? -EACCES : 0;
622 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
623 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
624 		break;
625 
626 	default:
627 		return -EINVAL;
628 	}
629 
630 	if (!acl) {
631 		/* Remove xattr if it can be presented via mode. */
632 		size = 0;
633 		value = NULL;
634 		flags = XATTR_REPLACE;
635 	} else {
636 		size = posix_acl_xattr_size(acl->a_count);
637 		value = kmalloc(size, GFP_NOFS);
638 		if (!value)
639 			return -ENOMEM;
640 		err = posix_acl_to_xattr(&init_user_ns, acl, value, size);
641 		if (err < 0)
642 			goto out;
643 		flags = 0;
644 	}
645 
646 	err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0);
647 	if (err == -ENODATA && !size)
648 		err = 0; /* Removing non existed xattr. */
649 	if (!err) {
650 		set_cached_acl(inode, type, acl);
651 		if (inode->i_mode != mode) {
652 			inode->i_mode = mode;
653 			mark_inode_dirty(inode);
654 		}
655 	}
656 
657 out:
658 	kfree(value);
659 
660 	return err;
661 }
662 
663 /*
664  * ntfs_set_acl - inode_operations::set_acl
665  */
ntfs_set_acl(struct user_namespace * mnt_userns,struct inode * inode,struct posix_acl * acl,int type)666 int ntfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
667 		 struct posix_acl *acl, int type)
668 {
669 	return ntfs_set_acl_ex(mnt_userns, inode, acl, type, false);
670 }
671 
672 /*
673  * ntfs_init_acl - Initialize the ACLs of a new inode.
674  *
675  * Called from ntfs_create_inode().
676  */
ntfs_init_acl(struct user_namespace * mnt_userns,struct inode * inode,struct inode * dir)677 int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
678 		  struct inode *dir)
679 {
680 	struct posix_acl *default_acl, *acl;
681 	int err;
682 
683 	err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
684 	if (err)
685 		return err;
686 
687 	if (default_acl) {
688 		err = ntfs_set_acl_ex(mnt_userns, inode, default_acl,
689 				      ACL_TYPE_DEFAULT, true);
690 		posix_acl_release(default_acl);
691 	} else {
692 		inode->i_default_acl = NULL;
693 	}
694 
695 	if (acl) {
696 		if (!err)
697 			err = ntfs_set_acl_ex(mnt_userns, inode, acl,
698 					      ACL_TYPE_ACCESS, true);
699 		posix_acl_release(acl);
700 	} else {
701 		inode->i_acl = NULL;
702 	}
703 
704 	return err;
705 }
706 #endif
707 
708 /*
709  * ntfs_acl_chmod - Helper for ntfs3_setattr().
710  */
ntfs_acl_chmod(struct user_namespace * mnt_userns,struct inode * inode)711 int ntfs_acl_chmod(struct user_namespace *mnt_userns, struct inode *inode)
712 {
713 	struct super_block *sb = inode->i_sb;
714 
715 	if (!(sb->s_flags & SB_POSIXACL))
716 		return 0;
717 
718 	if (S_ISLNK(inode->i_mode))
719 		return -EOPNOTSUPP;
720 
721 	return posix_acl_chmod(mnt_userns, inode, inode->i_mode);
722 }
723 
724 /*
725  * ntfs_permission - inode_operations::permission
726  */
ntfs_permission(struct user_namespace * mnt_userns,struct inode * inode,int mask)727 int ntfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
728 		    int mask)
729 {
730 	if (ntfs_sb(inode->i_sb)->options->noacsrules) {
731 		/* "No access rules" mode - Allow all changes. */
732 		return 0;
733 	}
734 
735 	return generic_permission(mnt_userns, inode, mask);
736 }
737 
738 /*
739  * ntfs_listxattr - inode_operations::listxattr
740  */
ntfs_listxattr(struct dentry * dentry,char * buffer,size_t size)741 ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
742 {
743 	struct inode *inode = d_inode(dentry);
744 	struct ntfs_inode *ni = ntfs_i(inode);
745 	ssize_t ret;
746 
747 	if (!(ni->ni_flags & NI_FLAG_EA)) {
748 		/* no xattr in file */
749 		return 0;
750 	}
751 
752 	ni_lock(ni);
753 
754 	ret = ntfs_list_ea(ni, buffer, size);
755 
756 	ni_unlock(ni);
757 
758 	return ret;
759 }
760 
ntfs_getxattr(const struct xattr_handler * handler,struct dentry * de,struct inode * inode,const char * name,void * buffer,size_t size)761 static int ntfs_getxattr(const struct xattr_handler *handler, struct dentry *de,
762 			 struct inode *inode, const char *name, void *buffer,
763 			 size_t size)
764 {
765 	int err;
766 	struct ntfs_inode *ni = ntfs_i(inode);
767 	size_t name_len = strlen(name);
768 
769 	/* Dispatch request. */
770 	if (name_len == sizeof(SYSTEM_DOS_ATTRIB) - 1 &&
771 	    !memcmp(name, SYSTEM_DOS_ATTRIB, sizeof(SYSTEM_DOS_ATTRIB))) {
772 		/* system.dos_attrib */
773 		if (!buffer) {
774 			err = sizeof(u8);
775 		} else if (size < sizeof(u8)) {
776 			err = -ENODATA;
777 		} else {
778 			err = sizeof(u8);
779 			*(u8 *)buffer = le32_to_cpu(ni->std_fa);
780 		}
781 		goto out;
782 	}
783 
784 	if (name_len == sizeof(SYSTEM_NTFS_ATTRIB) - 1 &&
785 	    !memcmp(name, SYSTEM_NTFS_ATTRIB, sizeof(SYSTEM_NTFS_ATTRIB))) {
786 		/* system.ntfs_attrib */
787 		if (!buffer) {
788 			err = sizeof(u32);
789 		} else if (size < sizeof(u32)) {
790 			err = -ENODATA;
791 		} else {
792 			err = sizeof(u32);
793 			*(u32 *)buffer = le32_to_cpu(ni->std_fa);
794 		}
795 		goto out;
796 	}
797 
798 	if (name_len == sizeof(SYSTEM_NTFS_SECURITY) - 1 &&
799 	    !memcmp(name, SYSTEM_NTFS_SECURITY, sizeof(SYSTEM_NTFS_SECURITY))) {
800 		/* system.ntfs_security*/
801 		struct SECURITY_DESCRIPTOR_RELATIVE *sd = NULL;
802 		size_t sd_size = 0;
803 
804 		if (!is_ntfs3(ni->mi.sbi)) {
805 			/* We should get nt4 security. */
806 			err = -EINVAL;
807 			goto out;
808 		} else if (le32_to_cpu(ni->std_security_id) <
809 			   SECURITY_ID_FIRST) {
810 			err = -ENOENT;
811 			goto out;
812 		}
813 
814 		err = ntfs_get_security_by_id(ni->mi.sbi, ni->std_security_id,
815 					      &sd, &sd_size);
816 		if (err)
817 			goto out;
818 
819 		if (!is_sd_valid(sd, sd_size)) {
820 			ntfs_inode_warn(
821 				inode,
822 				"looks like you get incorrect security descriptor id=%u",
823 				ni->std_security_id);
824 		}
825 
826 		if (!buffer) {
827 			err = sd_size;
828 		} else if (size < sd_size) {
829 			err = -ENODATA;
830 		} else {
831 			err = sd_size;
832 			memcpy(buffer, sd, sd_size);
833 		}
834 		kfree(sd);
835 		goto out;
836 	}
837 
838 	/* Deal with NTFS extended attribute. */
839 	err = ntfs_get_ea(inode, name, name_len, buffer, size, NULL);
840 
841 out:
842 	return err;
843 }
844 
845 /*
846  * ntfs_setxattr - inode_operations::setxattr
847  */
ntfs_setxattr(const struct xattr_handler * handler,struct user_namespace * mnt_userns,struct dentry * de,struct inode * inode,const char * name,const void * value,size_t size,int flags)848 static noinline int ntfs_setxattr(const struct xattr_handler *handler,
849 				  struct user_namespace *mnt_userns,
850 				  struct dentry *de, struct inode *inode,
851 				  const char *name, const void *value,
852 				  size_t size, int flags)
853 {
854 	int err = -EINVAL;
855 	struct ntfs_inode *ni = ntfs_i(inode);
856 	size_t name_len = strlen(name);
857 	enum FILE_ATTRIBUTE new_fa;
858 
859 	/* Dispatch request. */
860 	if (name_len == sizeof(SYSTEM_DOS_ATTRIB) - 1 &&
861 	    !memcmp(name, SYSTEM_DOS_ATTRIB, sizeof(SYSTEM_DOS_ATTRIB))) {
862 		if (sizeof(u8) != size)
863 			goto out;
864 		new_fa = cpu_to_le32(*(u8 *)value);
865 		goto set_new_fa;
866 	}
867 
868 	if (name_len == sizeof(SYSTEM_NTFS_ATTRIB) - 1 &&
869 	    !memcmp(name, SYSTEM_NTFS_ATTRIB, sizeof(SYSTEM_NTFS_ATTRIB))) {
870 		if (size != sizeof(u32))
871 			goto out;
872 		new_fa = cpu_to_le32(*(u32 *)value);
873 
874 		if (S_ISREG(inode->i_mode)) {
875 			/* Process compressed/sparsed in special way. */
876 			ni_lock(ni);
877 			err = ni_new_attr_flags(ni, new_fa);
878 			ni_unlock(ni);
879 			if (err)
880 				goto out;
881 		}
882 set_new_fa:
883 		/*
884 		 * Thanks Mark Harmstone:
885 		 * Keep directory bit consistency.
886 		 */
887 		if (S_ISDIR(inode->i_mode))
888 			new_fa |= FILE_ATTRIBUTE_DIRECTORY;
889 		else
890 			new_fa &= ~FILE_ATTRIBUTE_DIRECTORY;
891 
892 		if (ni->std_fa != new_fa) {
893 			ni->std_fa = new_fa;
894 			if (new_fa & FILE_ATTRIBUTE_READONLY)
895 				inode->i_mode &= ~0222;
896 			else
897 				inode->i_mode |= 0222;
898 			/* Std attribute always in primary record. */
899 			ni->mi.dirty = true;
900 			mark_inode_dirty(inode);
901 		}
902 		err = 0;
903 
904 		goto out;
905 	}
906 
907 	if (name_len == sizeof(SYSTEM_NTFS_SECURITY) - 1 &&
908 	    !memcmp(name, SYSTEM_NTFS_SECURITY, sizeof(SYSTEM_NTFS_SECURITY))) {
909 		/* system.ntfs_security*/
910 		__le32 security_id;
911 		bool inserted;
912 		struct ATTR_STD_INFO5 *std;
913 
914 		if (!is_ntfs3(ni->mi.sbi)) {
915 			/*
916 			 * We should replace ATTR_SECURE.
917 			 * Skip this way cause it is nt4 feature.
918 			 */
919 			err = -EINVAL;
920 			goto out;
921 		}
922 
923 		if (!is_sd_valid(value, size)) {
924 			err = -EINVAL;
925 			ntfs_inode_warn(
926 				inode,
927 				"you try to set invalid security descriptor");
928 			goto out;
929 		}
930 
931 		err = ntfs_insert_security(ni->mi.sbi, value, size,
932 					   &security_id, &inserted);
933 		if (err)
934 			goto out;
935 
936 		ni_lock(ni);
937 		std = ni_std5(ni);
938 		if (!std) {
939 			err = -EINVAL;
940 		} else if (std->security_id != security_id) {
941 			std->security_id = ni->std_security_id = security_id;
942 			/* Std attribute always in primary record. */
943 			ni->mi.dirty = true;
944 			mark_inode_dirty(&ni->vfs_inode);
945 		}
946 		ni_unlock(ni);
947 		goto out;
948 	}
949 
950 	/* Deal with NTFS extended attribute. */
951 	err = ntfs_set_ea(inode, name, name_len, value, size, flags, 0);
952 
953 out:
954 	inode->i_ctime = current_time(inode);
955 	mark_inode_dirty(inode);
956 
957 	return err;
958 }
959 
960 /*
961  * ntfs_save_wsl_perm
962  *
963  * save uid/gid/mode in xattr
964  */
ntfs_save_wsl_perm(struct inode * inode)965 int ntfs_save_wsl_perm(struct inode *inode)
966 {
967 	int err;
968 	__le32 value;
969 	struct ntfs_inode *ni = ntfs_i(inode);
970 
971 	ni_lock(ni);
972 	value = cpu_to_le32(i_uid_read(inode));
973 	err = ntfs_set_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value,
974 			  sizeof(value), 0, true); /* true == already locked. */
975 	if (err)
976 		goto out;
977 
978 	value = cpu_to_le32(i_gid_read(inode));
979 	err = ntfs_set_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value,
980 			  sizeof(value), 0, true);
981 	if (err)
982 		goto out;
983 
984 	value = cpu_to_le32(inode->i_mode);
985 	err = ntfs_set_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value,
986 			  sizeof(value), 0, true);
987 	if (err)
988 		goto out;
989 
990 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
991 		value = cpu_to_le32(inode->i_rdev);
992 		err = ntfs_set_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &value,
993 				  sizeof(value), 0, true);
994 		if (err)
995 			goto out;
996 	}
997 
998 out:
999 	ni_unlock(ni);
1000 	/* In case of error should we delete all WSL xattr? */
1001 	return err;
1002 }
1003 
1004 /*
1005  * ntfs_get_wsl_perm
1006  *
1007  * get uid/gid/mode from xattr
1008  * it is called from ntfs_iget5->ntfs_read_mft
1009  */
ntfs_get_wsl_perm(struct inode * inode)1010 void ntfs_get_wsl_perm(struct inode *inode)
1011 {
1012 	size_t sz;
1013 	__le32 value[3];
1014 
1015 	if (ntfs_get_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value[0],
1016 			sizeof(value[0]), &sz) == sizeof(value[0]) &&
1017 	    ntfs_get_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value[1],
1018 			sizeof(value[1]), &sz) == sizeof(value[1]) &&
1019 	    ntfs_get_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value[2],
1020 			sizeof(value[2]), &sz) == sizeof(value[2])) {
1021 		i_uid_write(inode, (uid_t)le32_to_cpu(value[0]));
1022 		i_gid_write(inode, (gid_t)le32_to_cpu(value[1]));
1023 		inode->i_mode = le32_to_cpu(value[2]);
1024 
1025 		if (ntfs_get_ea(inode, "$LXDEV", sizeof("$$LXDEV") - 1,
1026 				&value[0], sizeof(value),
1027 				&sz) == sizeof(value[0])) {
1028 			inode->i_rdev = le32_to_cpu(value[0]);
1029 		}
1030 	}
1031 }
1032 
ntfs_xattr_user_list(struct dentry * dentry)1033 static bool ntfs_xattr_user_list(struct dentry *dentry)
1034 {
1035 	return true;
1036 }
1037 
1038 // clang-format off
1039 static const struct xattr_handler ntfs_other_xattr_handler = {
1040 	.prefix	= "",
1041 	.get	= ntfs_getxattr,
1042 	.set	= ntfs_setxattr,
1043 	.list	= ntfs_xattr_user_list,
1044 };
1045 
1046 const struct xattr_handler *ntfs_xattr_handlers[] = {
1047 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
1048 	&posix_acl_access_xattr_handler,
1049 	&posix_acl_default_xattr_handler,
1050 #endif
1051 	&ntfs_other_xattr_handler,
1052 	NULL,
1053 };
1054 // clang-format on
1055