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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)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)
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 	ni_lock(ni);
329 
330 	run_init(&ea_run);
331 
332 	if (name_len > 255) {
333 		err = -ENAMETOOLONG;
334 		goto out;
335 	}
336 
337 	add = ALIGN(struct_size(ea_all, name, 1 + name_len + val_size), 4);
338 
339 	err = ntfs_read_ea(ni, &ea_all, add, &info);
340 	if (err)
341 		goto out;
342 
343 	if (!info) {
344 		memset(&ea_info, 0, sizeof(ea_info));
345 		size = 0;
346 		size_pack = 0;
347 	} else {
348 		memcpy(&ea_info, info, sizeof(ea_info));
349 		size = le32_to_cpu(ea_info.size);
350 		size_pack = ea_info.size_pack;
351 	}
352 
353 	if (info && find_ea(ea_all, size, name, name_len, &off, &ea_sz)) {
354 		struct EA_FULL *ea;
355 
356 		if (flags & XATTR_CREATE) {
357 			err = -EEXIST;
358 			goto out;
359 		}
360 
361 		ea = Add2Ptr(ea_all, off);
362 
363 		/*
364 		 * Check simple case when we try to insert xattr with the same value
365 		 * e.g. ntfs_save_wsl_perm
366 		 */
367 		if (val_size && le16_to_cpu(ea->elength) == val_size &&
368 		    !memcmp(ea->name + ea->name_len + 1, value, val_size)) {
369 			/* xattr already contains the required value. */
370 			goto out;
371 		}
372 
373 		/* Remove current xattr. */
374 		if (ea->flags & FILE_NEED_EA)
375 			le16_add_cpu(&ea_info.count, -1);
376 
377 		le16_add_cpu(&ea_info.size_pack, 0 - packed_ea_size(ea));
378 
379 		memmove(ea, Add2Ptr(ea, ea_sz), size - off - ea_sz);
380 
381 		size -= ea_sz;
382 		memset(Add2Ptr(ea_all, size), 0, ea_sz);
383 
384 		ea_info.size = cpu_to_le32(size);
385 
386 		if ((flags & XATTR_REPLACE) && !val_size) {
387 			/* Remove xattr. */
388 			goto update_ea;
389 		}
390 	} else {
391 		if (flags & XATTR_REPLACE) {
392 			err = -ENODATA;
393 			goto out;
394 		}
395 
396 		if (!ea_all) {
397 			ea_all = kzalloc(add, GFP_NOFS);
398 			if (!ea_all) {
399 				err = -ENOMEM;
400 				goto out;
401 			}
402 		}
403 	}
404 
405 	/* Append new xattr. */
406 	new_ea = Add2Ptr(ea_all, size);
407 	new_ea->size = cpu_to_le32(add);
408 	new_ea->flags = 0;
409 	new_ea->name_len = name_len;
410 	new_ea->elength = cpu_to_le16(val_size);
411 	memcpy(new_ea->name, name, name_len);
412 	new_ea->name[name_len] = 0;
413 	memcpy(new_ea->name + name_len + 1, value, val_size);
414 	new_pack = le16_to_cpu(ea_info.size_pack) + packed_ea_size(new_ea);
415 	ea_info.size_pack = cpu_to_le16(new_pack);
416 	/* New size of ATTR_EA. */
417 	size += add;
418 	ea_info.size = cpu_to_le32(size);
419 
420 	/*
421 	 * 1. Check ea_info.size_pack for overflow.
422 	 * 2. New attibute size must fit value from $AttrDef
423 	 */
424 	if (new_pack > 0xffff || size > sbi->ea_max_size) {
425 		ntfs_inode_warn(
426 			inode,
427 			"The size of extended attributes must not exceed 64KiB");
428 		err = -EFBIG; // -EINVAL?
429 		goto out;
430 	}
431 
432 update_ea:
433 
434 	if (!info) {
435 		/* Create xattr. */
436 		if (!size) {
437 			err = 0;
438 			goto out;
439 		}
440 
441 		err = ni_insert_resident(ni, sizeof(struct EA_INFO),
442 					 ATTR_EA_INFO, NULL, 0, NULL, NULL,
443 					 NULL);
444 		if (err)
445 			goto out;
446 
447 		err = ni_insert_resident(ni, 0, ATTR_EA, NULL, 0, NULL, NULL,
448 					 NULL);
449 		if (err)
450 			goto out;
451 	}
452 
453 	new_sz = size;
454 	err = attr_set_size(ni, ATTR_EA, NULL, 0, &ea_run, new_sz, &new_sz,
455 			    false, NULL);
456 	if (err)
457 		goto out;
458 
459 	le = NULL;
460 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA_INFO, NULL, 0, NULL, &mi);
461 	if (!attr) {
462 		err = -EINVAL;
463 		goto out;
464 	}
465 
466 	if (!size) {
467 		/* Delete xattr, ATTR_EA_INFO */
468 		ni_remove_attr_le(ni, attr, mi, le);
469 	} else {
470 		p = resident_data_ex(attr, sizeof(struct EA_INFO));
471 		if (!p) {
472 			err = -EINVAL;
473 			goto out;
474 		}
475 		memcpy(p, &ea_info, sizeof(struct EA_INFO));
476 		mi->dirty = true;
477 	}
478 
479 	le = NULL;
480 	attr = ni_find_attr(ni, NULL, &le, ATTR_EA, NULL, 0, NULL, &mi);
481 	if (!attr) {
482 		err = -EINVAL;
483 		goto out;
484 	}
485 
486 	if (!size) {
487 		/* Delete xattr, ATTR_EA */
488 		ni_remove_attr_le(ni, attr, mi, le);
489 	} else if (attr->non_res) {
490 		err = attr_load_runs_range(ni, ATTR_EA, NULL, 0, &ea_run, 0,
491 					   size);
492 		if (err)
493 			goto out;
494 
495 		err = ntfs_sb_write_run(sbi, &ea_run, 0, ea_all, size, 0);
496 		if (err)
497 			goto out;
498 	} else {
499 		p = resident_data_ex(attr, size);
500 		if (!p) {
501 			err = -EINVAL;
502 			goto out;
503 		}
504 		memcpy(p, ea_all, size);
505 		mi->dirty = true;
506 	}
507 
508 	/* Check if we delete the last xattr. */
509 	if (size)
510 		ni->ni_flags |= NI_FLAG_EA;
511 	else
512 		ni->ni_flags &= ~NI_FLAG_EA;
513 
514 	if (ea_info.size_pack != size_pack)
515 		ni->ni_flags |= NI_FLAG_UPDATE_PARENT;
516 	mark_inode_dirty(&ni->vfs_inode);
517 
518 out:
519 	ni_unlock(ni);
520 
521 	run_close(&ea_run);
522 	kfree(ea_all);
523 
524 	return err;
525 }
526 
527 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
ntfs_get_acl_ex(struct inode * inode,int type,int locked)528 static struct posix_acl *ntfs_get_acl_ex(struct inode *inode, int type,
529 					 int locked)
530 {
531 	struct ntfs_inode *ni = ntfs_i(inode);
532 	const char *name;
533 	size_t name_len;
534 	struct posix_acl *acl;
535 	size_t req;
536 	int err;
537 	void *buf;
538 
539 	/* Allocate PATH_MAX bytes. */
540 	buf = __getname();
541 	if (!buf)
542 		return ERR_PTR(-ENOMEM);
543 
544 	/* Possible values of 'type' was already checked above. */
545 	if (type == ACL_TYPE_ACCESS) {
546 		name = XATTR_NAME_POSIX_ACL_ACCESS;
547 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
548 	} else {
549 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
550 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
551 	}
552 
553 	if (!locked)
554 		ni_lock(ni);
555 
556 	err = ntfs_get_ea(inode, name, name_len, buf, PATH_MAX, &req);
557 
558 	if (!locked)
559 		ni_unlock(ni);
560 
561 	/* Translate extended attribute to acl. */
562 	if (err >= 0) {
563 		acl = posix_acl_from_xattr(&init_user_ns, buf, err);
564 	} else if (err == -ENODATA) {
565 		acl = NULL;
566 	} else {
567 		acl = ERR_PTR(err);
568 	}
569 
570 	if (!IS_ERR(acl))
571 		set_cached_acl(inode, type, acl);
572 
573 	__putname(buf);
574 
575 	return acl;
576 }
577 
578 /*
579  * ntfs_get_acl - inode_operations::get_acl
580  */
ntfs_get_acl(struct inode * inode,int type,bool rcu)581 struct posix_acl *ntfs_get_acl(struct inode *inode, int type, bool rcu)
582 {
583 	if (rcu)
584 		return ERR_PTR(-ECHILD);
585 
586 	return ntfs_get_acl_ex(inode, type, 0);
587 }
588 
ntfs_set_acl_ex(struct user_namespace * mnt_userns,struct inode * inode,struct posix_acl * acl,int type,bool init_acl)589 static noinline int ntfs_set_acl_ex(struct user_namespace *mnt_userns,
590 				    struct inode *inode, struct posix_acl *acl,
591 				    int type, bool init_acl)
592 {
593 	const char *name;
594 	size_t size, name_len;
595 	void *value;
596 	int err;
597 	int flags;
598 	umode_t mode;
599 
600 	if (S_ISLNK(inode->i_mode))
601 		return -EOPNOTSUPP;
602 
603 	mode = inode->i_mode;
604 	switch (type) {
605 	case ACL_TYPE_ACCESS:
606 		/* Do not change i_mode if we are in init_acl */
607 		if (acl && !init_acl) {
608 			err = posix_acl_update_mode(mnt_userns, inode, &mode,
609 						    &acl);
610 			if (err)
611 				return err;
612 		}
613 		name = XATTR_NAME_POSIX_ACL_ACCESS;
614 		name_len = sizeof(XATTR_NAME_POSIX_ACL_ACCESS) - 1;
615 		break;
616 
617 	case ACL_TYPE_DEFAULT:
618 		if (!S_ISDIR(inode->i_mode))
619 			return acl ? -EACCES : 0;
620 		name = XATTR_NAME_POSIX_ACL_DEFAULT;
621 		name_len = sizeof(XATTR_NAME_POSIX_ACL_DEFAULT) - 1;
622 		break;
623 
624 	default:
625 		return -EINVAL;
626 	}
627 
628 	if (!acl) {
629 		/* Remove xattr if it can be presented via mode. */
630 		size = 0;
631 		value = NULL;
632 		flags = XATTR_REPLACE;
633 	} else {
634 		size = posix_acl_xattr_size(acl->a_count);
635 		value = kmalloc(size, GFP_NOFS);
636 		if (!value)
637 			return -ENOMEM;
638 		err = posix_acl_to_xattr(&init_user_ns, acl, value, size);
639 		if (err < 0)
640 			goto out;
641 		flags = 0;
642 	}
643 
644 	err = ntfs_set_ea(inode, name, name_len, value, size, flags);
645 	if (err == -ENODATA && !size)
646 		err = 0; /* Removing non existed xattr. */
647 	if (!err) {
648 		set_cached_acl(inode, type, acl);
649 		if (inode->i_mode != mode) {
650 			inode->i_mode = mode;
651 			mark_inode_dirty(inode);
652 		}
653 	}
654 
655 out:
656 	kfree(value);
657 
658 	return err;
659 }
660 
661 /*
662  * ntfs_set_acl - inode_operations::set_acl
663  */
ntfs_set_acl(struct user_namespace * mnt_userns,struct inode * inode,struct posix_acl * acl,int type)664 int ntfs_set_acl(struct user_namespace *mnt_userns, struct inode *inode,
665 		 struct posix_acl *acl, int type)
666 {
667 	return ntfs_set_acl_ex(mnt_userns, inode, acl, type, false);
668 }
669 
670 /*
671  * ntfs_init_acl - Initialize the ACLs of a new inode.
672  *
673  * Called from ntfs_create_inode().
674  */
ntfs_init_acl(struct user_namespace * mnt_userns,struct inode * inode,struct inode * dir)675 int ntfs_init_acl(struct user_namespace *mnt_userns, struct inode *inode,
676 		  struct inode *dir)
677 {
678 	struct posix_acl *default_acl, *acl;
679 	int err;
680 
681 	err = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl);
682 	if (err)
683 		return err;
684 
685 	if (default_acl) {
686 		err = ntfs_set_acl_ex(mnt_userns, inode, default_acl,
687 				      ACL_TYPE_DEFAULT, true);
688 		posix_acl_release(default_acl);
689 	} else {
690 		inode->i_default_acl = NULL;
691 	}
692 
693 	if (!acl)
694 		inode->i_acl = NULL;
695 	else {
696 		if (!err)
697 			err = ntfs_set_acl_ex(mnt_userns, inode, acl,
698 					      ACL_TYPE_ACCESS, true);
699 		posix_acl_release(acl);
700 	}
701 
702 	return err;
703 }
704 #endif
705 
706 /*
707  * ntfs_acl_chmod - Helper for ntfs3_setattr().
708  */
ntfs_acl_chmod(struct user_namespace * mnt_userns,struct inode * inode)709 int ntfs_acl_chmod(struct user_namespace *mnt_userns, struct inode *inode)
710 {
711 	struct super_block *sb = inode->i_sb;
712 
713 	if (!(sb->s_flags & SB_POSIXACL))
714 		return 0;
715 
716 	if (S_ISLNK(inode->i_mode))
717 		return -EOPNOTSUPP;
718 
719 	return posix_acl_chmod(mnt_userns, inode, inode->i_mode);
720 }
721 
722 /*
723  * ntfs_permission - inode_operations::permission
724  */
ntfs_permission(struct user_namespace * mnt_userns,struct inode * inode,int mask)725 int ntfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
726 		    int mask)
727 {
728 	if (ntfs_sb(inode->i_sb)->options->noacsrules) {
729 		/* "No access rules" mode - Allow all changes. */
730 		return 0;
731 	}
732 
733 	return generic_permission(mnt_userns, inode, mask);
734 }
735 
736 /*
737  * ntfs_listxattr - inode_operations::listxattr
738  */
ntfs_listxattr(struct dentry * dentry,char * buffer,size_t size)739 ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
740 {
741 	struct inode *inode = d_inode(dentry);
742 	struct ntfs_inode *ni = ntfs_i(inode);
743 	ssize_t ret;
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 	size_t name_len = strlen(name);
766 
767 	/* Dispatch request. */
768 	if (name_len == sizeof(SYSTEM_DOS_ATTRIB) - 1 &&
769 	    !memcmp(name, SYSTEM_DOS_ATTRIB, sizeof(SYSTEM_DOS_ATTRIB))) {
770 		/* system.dos_attrib */
771 		if (!buffer) {
772 			err = sizeof(u8);
773 		} else if (size < sizeof(u8)) {
774 			err = -ENODATA;
775 		} else {
776 			err = sizeof(u8);
777 			*(u8 *)buffer = le32_to_cpu(ni->std_fa);
778 		}
779 		goto out;
780 	}
781 
782 	if (name_len == sizeof(SYSTEM_NTFS_ATTRIB) - 1 &&
783 	    !memcmp(name, SYSTEM_NTFS_ATTRIB, sizeof(SYSTEM_NTFS_ATTRIB))) {
784 		/* system.ntfs_attrib */
785 		if (!buffer) {
786 			err = sizeof(u32);
787 		} else if (size < sizeof(u32)) {
788 			err = -ENODATA;
789 		} else {
790 			err = sizeof(u32);
791 			*(u32 *)buffer = le32_to_cpu(ni->std_fa);
792 		}
793 		goto out;
794 	}
795 
796 	if (name_len == sizeof(SYSTEM_NTFS_SECURITY) - 1 &&
797 	    !memcmp(name, SYSTEM_NTFS_SECURITY, sizeof(SYSTEM_NTFS_SECURITY))) {
798 		/* system.ntfs_security*/
799 		struct SECURITY_DESCRIPTOR_RELATIVE *sd = NULL;
800 		size_t sd_size = 0;
801 
802 		if (!is_ntfs3(ni->mi.sbi)) {
803 			/* We should get nt4 security. */
804 			err = -EINVAL;
805 			goto out;
806 		} else if (le32_to_cpu(ni->std_security_id) <
807 			   SECURITY_ID_FIRST) {
808 			err = -ENOENT;
809 			goto out;
810 		}
811 
812 		err = ntfs_get_security_by_id(ni->mi.sbi, ni->std_security_id,
813 					      &sd, &sd_size);
814 		if (err)
815 			goto out;
816 
817 		if (!is_sd_valid(sd, sd_size)) {
818 			ntfs_inode_warn(
819 				inode,
820 				"looks like you get incorrect security descriptor id=%u",
821 				ni->std_security_id);
822 		}
823 
824 		if (!buffer) {
825 			err = sd_size;
826 		} else if (size < sd_size) {
827 			err = -ENODATA;
828 		} else {
829 			err = sd_size;
830 			memcpy(buffer, sd, sd_size);
831 		}
832 		kfree(sd);
833 		goto out;
834 	}
835 
836 	/* Deal with NTFS extended attribute. */
837 	err = ntfs_get_ea(inode, name, name_len, buffer, size, NULL);
838 
839 out:
840 	return err;
841 }
842 
843 /*
844  * ntfs_setxattr - inode_operations::setxattr
845  */
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)846 static noinline int ntfs_setxattr(const struct xattr_handler *handler,
847 				  struct user_namespace *mnt_userns,
848 				  struct dentry *de, struct inode *inode,
849 				  const char *name, const void *value,
850 				  size_t size, int flags)
851 {
852 	int err = -EINVAL;
853 	struct ntfs_inode *ni = ntfs_i(inode);
854 	size_t name_len = strlen(name);
855 	enum FILE_ATTRIBUTE new_fa;
856 
857 	/* Dispatch request. */
858 	if (name_len == sizeof(SYSTEM_DOS_ATTRIB) - 1 &&
859 	    !memcmp(name, SYSTEM_DOS_ATTRIB, sizeof(SYSTEM_DOS_ATTRIB))) {
860 		if (sizeof(u8) != size)
861 			goto out;
862 		new_fa = cpu_to_le32(*(u8 *)value);
863 		goto set_new_fa;
864 	}
865 
866 	if (name_len == sizeof(SYSTEM_NTFS_ATTRIB) - 1 &&
867 	    !memcmp(name, SYSTEM_NTFS_ATTRIB, sizeof(SYSTEM_NTFS_ATTRIB))) {
868 		if (size != sizeof(u32))
869 			goto out;
870 		new_fa = cpu_to_le32(*(u32 *)value);
871 
872 		if (S_ISREG(inode->i_mode)) {
873 			/* Process compressed/sparsed in special way. */
874 			ni_lock(ni);
875 			err = ni_new_attr_flags(ni, new_fa);
876 			ni_unlock(ni);
877 			if (err)
878 				goto out;
879 		}
880 set_new_fa:
881 		/*
882 		 * Thanks Mark Harmstone:
883 		 * Keep directory bit consistency.
884 		 */
885 		if (S_ISDIR(inode->i_mode))
886 			new_fa |= FILE_ATTRIBUTE_DIRECTORY;
887 		else
888 			new_fa &= ~FILE_ATTRIBUTE_DIRECTORY;
889 
890 		if (ni->std_fa != new_fa) {
891 			ni->std_fa = new_fa;
892 			if (new_fa & FILE_ATTRIBUTE_READONLY)
893 				inode->i_mode &= ~0222;
894 			else
895 				inode->i_mode |= 0222;
896 			/* Std attribute always in primary record. */
897 			ni->mi.dirty = true;
898 			mark_inode_dirty(inode);
899 		}
900 		err = 0;
901 
902 		goto out;
903 	}
904 
905 	if (name_len == sizeof(SYSTEM_NTFS_SECURITY) - 1 &&
906 	    !memcmp(name, SYSTEM_NTFS_SECURITY, sizeof(SYSTEM_NTFS_SECURITY))) {
907 		/* system.ntfs_security*/
908 		__le32 security_id;
909 		bool inserted;
910 		struct ATTR_STD_INFO5 *std;
911 
912 		if (!is_ntfs3(ni->mi.sbi)) {
913 			/*
914 			 * We should replace ATTR_SECURE.
915 			 * Skip this way cause it is nt4 feature.
916 			 */
917 			err = -EINVAL;
918 			goto out;
919 		}
920 
921 		if (!is_sd_valid(value, size)) {
922 			err = -EINVAL;
923 			ntfs_inode_warn(
924 				inode,
925 				"you try to set invalid security descriptor");
926 			goto out;
927 		}
928 
929 		err = ntfs_insert_security(ni->mi.sbi, value, size,
930 					   &security_id, &inserted);
931 		if (err)
932 			goto out;
933 
934 		ni_lock(ni);
935 		std = ni_std5(ni);
936 		if (!std) {
937 			err = -EINVAL;
938 		} else if (std->security_id != security_id) {
939 			std->security_id = ni->std_security_id = security_id;
940 			/* Std attribute always in primary record. */
941 			ni->mi.dirty = true;
942 			mark_inode_dirty(&ni->vfs_inode);
943 		}
944 		ni_unlock(ni);
945 		goto out;
946 	}
947 
948 	/* Deal with NTFS extended attribute. */
949 	err = ntfs_set_ea(inode, name, name_len, value, size, flags);
950 
951 out:
952 	inode->i_ctime = current_time(inode);
953 	mark_inode_dirty(inode);
954 
955 	return err;
956 }
957 
958 /*
959  * ntfs_save_wsl_perm
960  *
961  * save uid/gid/mode in xattr
962  */
ntfs_save_wsl_perm(struct inode * inode)963 int ntfs_save_wsl_perm(struct inode *inode)
964 {
965 	int err;
966 	__le32 value;
967 
968 	/* TODO: refactor this, so we don't lock 4 times in ntfs_set_ea */
969 	value = cpu_to_le32(i_uid_read(inode));
970 	err = ntfs_set_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value,
971 			  sizeof(value), 0);
972 	if (err)
973 		goto out;
974 
975 	value = cpu_to_le32(i_gid_read(inode));
976 	err = ntfs_set_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value,
977 			  sizeof(value), 0);
978 	if (err)
979 		goto out;
980 
981 	value = cpu_to_le32(inode->i_mode);
982 	err = ntfs_set_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value,
983 			  sizeof(value), 0);
984 	if (err)
985 		goto out;
986 
987 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
988 		value = cpu_to_le32(inode->i_rdev);
989 		err = ntfs_set_ea(inode, "$LXDEV", sizeof("$LXDEV") - 1, &value,
990 				  sizeof(value), 0);
991 		if (err)
992 			goto out;
993 	}
994 
995 out:
996 	/* In case of error should we delete all WSL xattr? */
997 	return err;
998 }
999 
1000 /*
1001  * ntfs_get_wsl_perm
1002  *
1003  * get uid/gid/mode from xattr
1004  * it is called from ntfs_iget5->ntfs_read_mft
1005  */
ntfs_get_wsl_perm(struct inode * inode)1006 void ntfs_get_wsl_perm(struct inode *inode)
1007 {
1008 	size_t sz;
1009 	__le32 value[3];
1010 
1011 	if (ntfs_get_ea(inode, "$LXUID", sizeof("$LXUID") - 1, &value[0],
1012 			sizeof(value[0]), &sz) == sizeof(value[0]) &&
1013 	    ntfs_get_ea(inode, "$LXGID", sizeof("$LXGID") - 1, &value[1],
1014 			sizeof(value[1]), &sz) == sizeof(value[1]) &&
1015 	    ntfs_get_ea(inode, "$LXMOD", sizeof("$LXMOD") - 1, &value[2],
1016 			sizeof(value[2]), &sz) == sizeof(value[2])) {
1017 		i_uid_write(inode, (uid_t)le32_to_cpu(value[0]));
1018 		i_gid_write(inode, (gid_t)le32_to_cpu(value[1]));
1019 		inode->i_mode = le32_to_cpu(value[2]);
1020 
1021 		if (ntfs_get_ea(inode, "$LXDEV", sizeof("$$LXDEV") - 1,
1022 				&value[0], sizeof(value),
1023 				&sz) == sizeof(value[0])) {
1024 			inode->i_rdev = le32_to_cpu(value[0]);
1025 		}
1026 	}
1027 }
1028 
ntfs_xattr_user_list(struct dentry * dentry)1029 static bool ntfs_xattr_user_list(struct dentry *dentry)
1030 {
1031 	return true;
1032 }
1033 
1034 // clang-format off
1035 static const struct xattr_handler ntfs_other_xattr_handler = {
1036 	.prefix	= "",
1037 	.get	= ntfs_getxattr,
1038 	.set	= ntfs_setxattr,
1039 	.list	= ntfs_xattr_user_list,
1040 };
1041 
1042 const struct xattr_handler *ntfs_xattr_handlers[] = {
1043 #ifdef CONFIG_NTFS3_FS_POSIX_ACL
1044 	&posix_acl_access_xattr_handler,
1045 	&posix_acl_default_xattr_handler,
1046 #endif
1047 	&ntfs_other_xattr_handler,
1048 	NULL,
1049 };
1050 // clang-format on
1051