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