xref: /linux/fs/smb/server/smbacl.c (revision 9a58da80053f992b285b6b7bebc694b0f284c443)
1 // SPDX-License-Identifier: LGPL-2.1+
2 /*
3  *   Copyright (C) International Business Machines  Corp., 2007,2008
4  *   Author(s): Steve French (sfrench@us.ibm.com)
5  *   Copyright (C) 2020 Samsung Electronics Co., Ltd.
6  *   Author(s): Namjae Jeon <linkinjeon@kernel.org>
7  */
8 
9 #include <linux/fs.h>
10 #include <linux/slab.h>
11 #include <linux/string.h>
12 #include <linux/mnt_idmapping.h>
13 
14 #include "smbacl.h"
15 #include "smb_common.h"
16 #include "server.h"
17 #include "misc.h"
18 #include "mgmt/share_config.h"
19 
20 static const struct smb_sid domain = {1, 4, {0, 0, 0, 0, 0, 5},
21 	{cpu_to_le32(21), cpu_to_le32(1), cpu_to_le32(2), cpu_to_le32(3),
22 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
23 
24 /* security id for everyone/world system group */
25 static const struct smb_sid creator_owner = {
26 	1, 1, {0, 0, 0, 0, 0, 3}, {0} };
27 /* security id for everyone/world system group */
28 static const struct smb_sid creator_group = {
29 	1, 1, {0, 0, 0, 0, 0, 3}, {cpu_to_le32(1)} };
30 /* security id for owner rights */
31 static const struct smb_sid sid_owner_rights = {
32 	1, 1, {0, 0, 0, 0, 0, 3}, {cpu_to_le32(4)} };
33 
34 /* security id for everyone/world system group */
35 static const struct smb_sid sid_everyone = {
36 	1, 1, {0, 0, 0, 0, 0, 1}, {0} };
37 /* security id for Authenticated Users system group */
38 static const struct smb_sid sid_authusers = {
39 	1, 1, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(11)} };
40 
41 /* S-1-22-1 Unmapped Unix users */
42 static const struct smb_sid sid_unix_users = {1, 1, {0, 0, 0, 0, 0, 22},
43 		{cpu_to_le32(1), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
44 
45 /* S-1-22-2 Unmapped Unix groups */
46 static const struct smb_sid sid_unix_groups = { 1, 1, {0, 0, 0, 0, 0, 22},
47 		{cpu_to_le32(2), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
48 
49 /*
50  * See http://technet.microsoft.com/en-us/library/hh509017(v=ws.10).aspx
51  */
52 
53 /* S-1-5-88 MS NFS and Apple style UID/GID/mode */
54 
55 /* S-1-5-88-1 Unix uid */
56 static const struct smb_sid sid_unix_NFS_users = { 1, 2, {0, 0, 0, 0, 0, 5},
57 	{cpu_to_le32(88),
58 	 cpu_to_le32(1), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
59 
60 /* S-1-5-88-2 Unix gid */
61 static const struct smb_sid sid_unix_NFS_groups = { 1, 2, {0, 0, 0, 0, 0, 5},
62 	{cpu_to_le32(88),
63 	 cpu_to_le32(2), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
64 
65 /* S-1-5-88-3 Unix mode */
66 static const struct smb_sid sid_unix_NFS_mode = { 1, 2, {0, 0, 0, 0, 0, 5},
67 	{cpu_to_le32(88),
68 	 cpu_to_le32(3), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
69 
70 /*
71  * if the two SIDs (roughly equivalent to a UUID for a user or group) are
72  * the same returns zero, if they do not match returns non-zero.
73  */
compare_sids(const struct smb_sid * ctsid,const struct smb_sid * cwsid)74 int compare_sids(const struct smb_sid *ctsid, const struct smb_sid *cwsid)
75 {
76 	int i;
77 	int num_subauth, num_sat, num_saw;
78 
79 	if (!ctsid || !cwsid)
80 		return 1;
81 
82 	/* compare the revision */
83 	if (ctsid->revision != cwsid->revision) {
84 		if (ctsid->revision > cwsid->revision)
85 			return 1;
86 		else
87 			return -1;
88 	}
89 
90 	/* compare all of the six auth values */
91 	for (i = 0; i < NUM_AUTHS; ++i) {
92 		if (ctsid->authority[i] != cwsid->authority[i]) {
93 			if (ctsid->authority[i] > cwsid->authority[i])
94 				return 1;
95 			else
96 				return -1;
97 		}
98 	}
99 
100 	/* compare all of the subauth values if any */
101 	num_sat = ctsid->num_subauth;
102 	num_saw = cwsid->num_subauth;
103 	num_subauth = min(num_sat, num_saw);
104 	if (num_subauth) {
105 		for (i = 0; i < num_subauth; ++i) {
106 			if (ctsid->sub_auth[i] != cwsid->sub_auth[i]) {
107 				if (le32_to_cpu(ctsid->sub_auth[i]) >
108 				    le32_to_cpu(cwsid->sub_auth[i]))
109 					return 1;
110 				else
111 					return -1;
112 			}
113 		}
114 	}
115 
116 	return 0; /* sids compare/match */
117 }
118 
smb_copy_sid(struct smb_sid * dst,const struct smb_sid * src)119 static void smb_copy_sid(struct smb_sid *dst, const struct smb_sid *src)
120 {
121 	int i;
122 
123 	dst->revision = src->revision;
124 	dst->num_subauth = min_t(u8, src->num_subauth, SID_MAX_SUB_AUTHORITIES);
125 	for (i = 0; i < NUM_AUTHS; ++i)
126 		dst->authority[i] = src->authority[i];
127 	for (i = 0; i < dst->num_subauth; ++i)
128 		dst->sub_auth[i] = src->sub_auth[i];
129 }
130 
131 /*
132  * change posix mode to reflect permissions
133  * pmode is the existing mode (we only want to overwrite part of this
134  * bits to set can be: S_IRWXU, S_IRWXG or S_IRWXO ie 00700 or 00070 or 00007
135  */
access_flags_to_mode(struct smb_fattr * fattr,__le32 ace_flags,int type)136 static umode_t access_flags_to_mode(struct smb_fattr *fattr, __le32 ace_flags,
137 				    int type)
138 {
139 	__u32 flags = le32_to_cpu(ace_flags);
140 	umode_t mode = 0;
141 
142 	if (flags & GENERIC_ALL) {
143 		mode = 0777;
144 		ksmbd_debug(SMB, "all perms\n");
145 		return mode;
146 	}
147 
148 	if ((flags & GENERIC_READ) || (flags & FILE_READ_RIGHTS))
149 		mode = 0444;
150 	if ((flags & GENERIC_WRITE) || (flags & FILE_WRITE_RIGHTS)) {
151 		mode |= 0222;
152 		if (S_ISDIR(fattr->cf_mode))
153 			mode |= 0111;
154 	}
155 	if ((flags & GENERIC_EXECUTE) || (flags & FILE_EXEC_RIGHTS))
156 		mode |= 0111;
157 
158 	if (type == ACCESS_DENIED_ACE_TYPE || type == ACCESS_DENIED_OBJECT_ACE_TYPE)
159 		mode = ~mode;
160 
161 	ksmbd_debug(SMB, "access flags 0x%x mode now %04o\n", flags, mode);
162 
163 	return mode;
164 }
165 
166 /*
167  * Generate access flags to reflect permissions mode is the existing mode.
168  * This function is called for every ACE in the DACL whose SID matches
169  * with either owner or group or everyone.
170  */
mode_to_access_flags(umode_t mode,umode_t bits_to_use,__u32 * pace_flags)171 static void mode_to_access_flags(umode_t mode, umode_t bits_to_use,
172 				 __u32 *pace_flags)
173 {
174 	/* reset access mask */
175 	*pace_flags = 0x0;
176 
177 	/* bits to use are either S_IRWXU or S_IRWXG or S_IRWXO */
178 	mode &= bits_to_use;
179 
180 	/*
181 	 * check for R/W/X UGO since we do not know whose flags
182 	 * is this but we have cleared all the bits sans RWX for
183 	 * either user or group or other as per bits_to_use
184 	 */
185 	if (mode & 0444)
186 		*pace_flags |= SET_FILE_READ_RIGHTS;
187 	if (mode & 0222)
188 		*pace_flags |= FILE_WRITE_RIGHTS;
189 	if (mode & 0111)
190 		*pace_flags |= SET_FILE_EXEC_RIGHTS;
191 
192 	ksmbd_debug(SMB, "mode: %o, access flags now 0x%x\n",
193 		    mode, *pace_flags);
194 }
195 
fill_ace_for_sid(struct smb_ace * pntace,const struct smb_sid * psid,int type,int flags,umode_t mode,umode_t bits)196 static __u16 fill_ace_for_sid(struct smb_ace *pntace,
197 			      const struct smb_sid *psid, int type, int flags,
198 			      umode_t mode, umode_t bits)
199 {
200 	int i;
201 	__u16 size = 0;
202 	__u32 access_req = 0;
203 
204 	pntace->type = type;
205 	pntace->flags = flags;
206 	mode_to_access_flags(mode, bits, &access_req);
207 	if (!access_req)
208 		access_req = SET_MINIMUM_RIGHTS;
209 	pntace->access_req = cpu_to_le32(access_req);
210 
211 	pntace->sid.revision = psid->revision;
212 	pntace->sid.num_subauth = psid->num_subauth;
213 	for (i = 0; i < NUM_AUTHS; i++)
214 		pntace->sid.authority[i] = psid->authority[i];
215 	for (i = 0; i < psid->num_subauth; i++)
216 		pntace->sid.sub_auth[i] = psid->sub_auth[i];
217 
218 	size = 1 + 1 + 2 + 4 + 1 + 1 + 6 + (psid->num_subauth * 4);
219 	pntace->size = cpu_to_le16(size);
220 
221 	return size;
222 }
223 
id_to_sid(unsigned int cid,uint sidtype,struct smb_sid * ssid)224 void id_to_sid(unsigned int cid, uint sidtype, struct smb_sid *ssid)
225 {
226 	switch (sidtype) {
227 	case SIDOWNER:
228 		smb_copy_sid(ssid, &server_conf.domain_sid);
229 		break;
230 	case SIDUNIX_USER:
231 		smb_copy_sid(ssid, &sid_unix_users);
232 		break;
233 	case SIDUNIX_GROUP:
234 		smb_copy_sid(ssid, &sid_unix_groups);
235 		break;
236 	case SIDCREATOR_OWNER:
237 		smb_copy_sid(ssid, &creator_owner);
238 		return;
239 	case SIDCREATOR_GROUP:
240 		smb_copy_sid(ssid, &creator_group);
241 		return;
242 	case SIDNFS_USER:
243 		smb_copy_sid(ssid, &sid_unix_NFS_users);
244 		break;
245 	case SIDNFS_GROUP:
246 		smb_copy_sid(ssid, &sid_unix_NFS_groups);
247 		break;
248 	case SIDNFS_MODE:
249 		smb_copy_sid(ssid, &sid_unix_NFS_mode);
250 		break;
251 	default:
252 		return;
253 	}
254 
255 	/* RID */
256 	ssid->sub_auth[ssid->num_subauth] = cpu_to_le32(cid);
257 	ssid->num_subauth++;
258 }
259 
sid_to_id(struct mnt_idmap * idmap,struct smb_sid * psid,uint sidtype,struct smb_fattr * fattr)260 static int sid_to_id(struct mnt_idmap *idmap,
261 		     struct smb_sid *psid, uint sidtype,
262 		     struct smb_fattr *fattr)
263 {
264 	const struct smb_sid *sid_prefix;
265 	int rc = -EINVAL;
266 
267 	/*
268 	 * If we have too many subauthorities, then something is really wrong.
269 	 * Just return an error.
270 	 */
271 	if (unlikely(psid->num_subauth > SID_MAX_SUB_AUTHORITIES)) {
272 		pr_err("%s: %u subauthorities is too many!\n",
273 		       __func__, psid->num_subauth);
274 		return -EIO;
275 	}
276 
277 	if (psid->num_subauth == 0) {
278 		pr_err("%s: zero subauthorities!\n", __func__);
279 		return -EIO;
280 	}
281 
282 	if (sidtype == SIDOWNER) {
283 		kuid_t uid;
284 		uid_t id;
285 
286 		/* Only the server domain RID has a local uid representation. */
287 		sid_prefix = &server_conf.domain_sid;
288 		if (psid->num_subauth != sid_prefix->num_subauth + 1 ||
289 		    compare_sids(psid, sid_prefix))
290 			return -EINVAL;
291 
292 		id = le32_to_cpu(psid->sub_auth[psid->num_subauth - 1]);
293 		uid = KUIDT_INIT(id);
294 		uid = from_vfsuid(idmap, &init_user_ns, VFSUIDT_INIT(uid));
295 		if (uid_valid(uid)) {
296 			fattr->cf_uid = uid;
297 			rc = 0;
298 		}
299 	} else {
300 		kgid_t gid;
301 		gid_t id;
302 
303 		/* Local gids are represented by S-1-22-2-<gid>. */
304 		sid_prefix = &sid_unix_groups;
305 		if (psid->num_subauth != sid_prefix->num_subauth + 1 ||
306 		    compare_sids(psid, sid_prefix))
307 			return -EINVAL;
308 
309 		id = le32_to_cpu(psid->sub_auth[psid->num_subauth - 1]);
310 		gid = KGIDT_INIT(id);
311 		gid = from_vfsgid(idmap, &init_user_ns, VFSGIDT_INIT(gid));
312 		if (gid_valid(gid)) {
313 			fattr->cf_gid = gid;
314 			rc = 0;
315 		}
316 	}
317 
318 	return rc;
319 }
320 
posix_state_to_acl(struct posix_acl_state * state,struct posix_acl_entry * pace)321 void posix_state_to_acl(struct posix_acl_state *state,
322 			struct posix_acl_entry *pace)
323 {
324 	int i;
325 
326 	pace->e_tag = ACL_USER_OBJ;
327 	pace->e_perm = state->owner.allow;
328 	for (i = 0; i < state->users->n; i++) {
329 		pace++;
330 		pace->e_tag = ACL_USER;
331 		pace->e_uid = state->users->aces[i].uid;
332 		pace->e_perm = state->users->aces[i].perms.allow;
333 	}
334 
335 	pace++;
336 	pace->e_tag = ACL_GROUP_OBJ;
337 	pace->e_perm = state->group.allow;
338 
339 	for (i = 0; i < state->groups->n; i++) {
340 		pace++;
341 		pace->e_tag = ACL_GROUP;
342 		pace->e_gid = state->groups->aces[i].gid;
343 		pace->e_perm = state->groups->aces[i].perms.allow;
344 	}
345 
346 	if (state->users->n || state->groups->n) {
347 		pace++;
348 		pace->e_tag = ACL_MASK;
349 		pace->e_perm = state->mask.allow;
350 	}
351 
352 	pace++;
353 	pace->e_tag = ACL_OTHER;
354 	pace->e_perm = state->other.allow;
355 }
356 
init_acl_state(struct posix_acl_state * state,u16 cnt)357 int init_acl_state(struct posix_acl_state *state, u16 cnt)
358 {
359 	int alloc;
360 
361 	memset(state, 0, sizeof(struct posix_acl_state));
362 	/*
363 	 * In the worst case, each individual acl could be for a distinct
364 	 * named user or group, but we don't know which, so we allocate
365 	 * enough space for either:
366 	 */
367 	alloc = sizeof(struct posix_ace_state_array)
368 		+ cnt * sizeof(struct posix_user_ace_state);
369 	state->users = kzalloc(alloc, KSMBD_DEFAULT_GFP);
370 	if (!state->users)
371 		return -ENOMEM;
372 	state->groups = kzalloc(alloc, KSMBD_DEFAULT_GFP);
373 	if (!state->groups) {
374 		kfree(state->users);
375 		return -ENOMEM;
376 	}
377 	return 0;
378 }
379 
free_acl_state(struct posix_acl_state * state)380 void free_acl_state(struct posix_acl_state *state)
381 {
382 	kfree(state->users);
383 	kfree(state->groups);
384 }
385 
parse_dacl(struct mnt_idmap * idmap,struct smb_acl * pdacl,char * end_of_acl,struct smb_sid * pownersid,struct smb_sid * pgrpsid,struct smb_fattr * fattr)386 static int parse_dacl(struct mnt_idmap *idmap,
387 		      struct smb_acl *pdacl, char *end_of_acl,
388 		      struct smb_sid *pownersid, struct smb_sid *pgrpsid,
389 		      struct smb_fattr *fattr)
390 {
391 	int i, ret;
392 	u16 num_aces = 0;
393 	u16 dacl_size;
394 	unsigned int acl_size;
395 	char *acl_base;
396 	struct smb_ace **ppace;
397 	struct posix_acl_entry *cf_pace, *cf_pdace;
398 	struct posix_acl_state acl_state, default_acl_state;
399 	umode_t mode = 0, acl_mode;
400 	bool owner_found = false, group_found = false, others_found = false;
401 
402 	if (!pdacl)
403 		return 0;
404 
405 	/* validate that we do not go past end of acl */
406 	if (end_of_acl < (char *)pdacl + sizeof(struct smb_acl) ||
407 	    end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) {
408 		pr_err("ACL too small to parse DACL\n");
409 		return -EINVAL;
410 	}
411 
412 	ksmbd_debug(SMB, "DACL revision %d size %d num aces %d\n",
413 		    le16_to_cpu(pdacl->revision), le16_to_cpu(pdacl->size),
414 		    le16_to_cpu(pdacl->num_aces));
415 
416 	acl_base = (char *)pdacl;
417 	acl_size = sizeof(struct smb_acl);
418 
419 	num_aces = le16_to_cpu(pdacl->num_aces);
420 	if (num_aces <= 0)
421 		return 0;
422 
423 	dacl_size = le16_to_cpu(pdacl->size);
424 	if (dacl_size < sizeof(struct smb_acl))
425 		return -EINVAL;
426 
427 	if (num_aces > (dacl_size - sizeof(struct smb_acl)) /
428 			(offsetof(struct smb_ace, sid) +
429 			 offsetof(struct smb_sid, sub_auth) + sizeof(__le16)))
430 		return -EINVAL;
431 
432 	ret = init_acl_state(&acl_state, num_aces);
433 	if (ret)
434 		return ret;
435 	ret = init_acl_state(&default_acl_state, num_aces);
436 	if (ret) {
437 		free_acl_state(&acl_state);
438 		return ret;
439 	}
440 
441 	ppace = kmalloc_objs(struct smb_ace *, num_aces, KSMBD_DEFAULT_GFP);
442 	if (!ppace) {
443 		free_acl_state(&default_acl_state);
444 		free_acl_state(&acl_state);
445 		return -ENOMEM;
446 	}
447 
448 	/*
449 	 * reset rwx permissions for user/group/other.
450 	 * Also, if num_aces is 0 i.e. DACL has no ACEs,
451 	 * user/group/other have no permissions
452 	 */
453 	for (i = 0; i < num_aces; ++i) {
454 		if (end_of_acl - acl_base < acl_size) {
455 			ret = -EINVAL;
456 			goto out;
457 		}
458 
459 		ppace[i] = (struct smb_ace *)(acl_base + acl_size);
460 		acl_base = (char *)ppace[i];
461 		acl_size = offsetof(struct smb_ace, sid) +
462 			offsetof(struct smb_sid, sub_auth);
463 
464 		if (end_of_acl - acl_base < acl_size ||
465 		    ppace[i]->sid.num_subauth == 0 ||
466 		    ppace[i]->sid.num_subauth > SID_MAX_SUB_AUTHORITIES ||
467 		    (end_of_acl - acl_base <
468 		     acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth) ||
469 		    (le16_to_cpu(ppace[i]->size) <
470 		     acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth)) {
471 			ret = -EINVAL;
472 			goto out;
473 		}
474 
475 		acl_size = le16_to_cpu(ppace[i]->size);
476 		ppace[i]->access_req =
477 			smb_map_generic_desired_access(ppace[i]->access_req);
478 
479 		if (ppace[i]->sid.num_subauth >= 3 &&
480 		    !(compare_sids(&ppace[i]->sid, &sid_unix_NFS_mode))) {
481 			fattr->cf_mode =
482 				le32_to_cpu(ppace[i]->sid.sub_auth[2]);
483 			break;
484 		} else if (!compare_sids(&ppace[i]->sid, pownersid)) {
485 			acl_mode = access_flags_to_mode(fattr,
486 							ppace[i]->access_req,
487 							ppace[i]->type);
488 			acl_mode &= 0700;
489 
490 			if (!owner_found) {
491 				mode &= ~(0700);
492 				mode |= acl_mode;
493 			}
494 			owner_found = true;
495 		} else if (!compare_sids(&ppace[i]->sid, pgrpsid) ||
496 			   ppace[i]->sid.sub_auth[ppace[i]->sid.num_subauth - 1] ==
497 			    DOMAIN_USER_RID_LE) {
498 			acl_mode = access_flags_to_mode(fattr,
499 							ppace[i]->access_req,
500 							ppace[i]->type);
501 			acl_mode &= 0070;
502 			if (!group_found) {
503 				mode &= ~(0070);
504 				mode |= acl_mode;
505 			}
506 			group_found = true;
507 		} else if (!compare_sids(&ppace[i]->sid, &sid_everyone)) {
508 			acl_mode = access_flags_to_mode(fattr,
509 							ppace[i]->access_req,
510 							ppace[i]->type);
511 			acl_mode &= 0007;
512 			if (!others_found) {
513 				mode &= ~(0007);
514 				mode |= acl_mode;
515 			}
516 			others_found = true;
517 		} else if (!compare_sids(&ppace[i]->sid, &creator_owner)) {
518 			continue;
519 		} else if (!compare_sids(&ppace[i]->sid, &creator_group)) {
520 			continue;
521 		} else if (!compare_sids(&ppace[i]->sid, &sid_authusers)) {
522 			continue;
523 		} else {
524 			struct smb_fattr temp_fattr;
525 
526 			acl_mode = access_flags_to_mode(fattr, ppace[i]->access_req,
527 							ppace[i]->type);
528 			temp_fattr.cf_uid = INVALID_UID;
529 			ret = sid_to_id(idmap, &ppace[i]->sid, SIDOWNER, &temp_fattr);
530 			if (ret || uid_eq(temp_fattr.cf_uid, INVALID_UID)) {
531 				pr_err_ratelimited("%s: Error %d mapping Owner SID to uid\n",
532 						   __func__, ret);
533 				continue;
534 			}
535 
536 			acl_state.owner.allow = ((acl_mode & 0700) >> 6) | 0004;
537 			acl_state.users->aces[acl_state.users->n].uid =
538 				temp_fattr.cf_uid;
539 			acl_state.users->aces[acl_state.users->n++].perms.allow =
540 				((acl_mode & 0700) >> 6) | 0004;
541 			default_acl_state.owner.allow = ((acl_mode & 0700) >> 6) | 0004;
542 			default_acl_state.users->aces[default_acl_state.users->n].uid =
543 				temp_fattr.cf_uid;
544 			default_acl_state.users->aces[default_acl_state.users->n++].perms.allow =
545 				((acl_mode & 0700) >> 6) | 0004;
546 		}
547 	}
548 
549 	if (owner_found) {
550 		/* The owner must be set to at least read-only. */
551 		acl_state.owner.allow = ((mode & 0700) >> 6) | 0004;
552 		acl_state.users->aces[acl_state.users->n].uid = fattr->cf_uid;
553 		acl_state.users->aces[acl_state.users->n++].perms.allow =
554 			((mode & 0700) >> 6) | 0004;
555 		default_acl_state.owner.allow = ((mode & 0700) >> 6) | 0004;
556 		default_acl_state.users->aces[default_acl_state.users->n].uid =
557 			fattr->cf_uid;
558 		default_acl_state.users->aces[default_acl_state.users->n++].perms.allow =
559 			((mode & 0700) >> 6) | 0004;
560 	}
561 
562 	if (group_found) {
563 		acl_state.group.allow = (mode & 0070) >> 3;
564 		acl_state.groups->aces[acl_state.groups->n].gid =
565 			fattr->cf_gid;
566 		acl_state.groups->aces[acl_state.groups->n++].perms.allow =
567 			(mode & 0070) >> 3;
568 		default_acl_state.group.allow = (mode & 0070) >> 3;
569 		default_acl_state.groups->aces[default_acl_state.groups->n].gid =
570 			fattr->cf_gid;
571 		default_acl_state.groups->aces[default_acl_state.groups->n++].perms.allow =
572 			(mode & 0070) >> 3;
573 	}
574 
575 	if (others_found) {
576 		fattr->cf_mode &= ~(0007);
577 		fattr->cf_mode |= mode & 0007;
578 
579 		acl_state.other.allow = mode & 0007;
580 		default_acl_state.other.allow = mode & 0007;
581 	}
582 
583 	if (acl_state.users->n || acl_state.groups->n) {
584 		acl_state.mask.allow = 0x07;
585 
586 		if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) {
587 			fattr->cf_acls =
588 				posix_acl_alloc(acl_state.users->n +
589 					acl_state.groups->n + 4, KSMBD_DEFAULT_GFP);
590 			if (!fattr->cf_acls) {
591 				ret = -ENOMEM;
592 				goto out;
593 			}
594 			cf_pace = fattr->cf_acls->a_entries;
595 			posix_state_to_acl(&acl_state, cf_pace);
596 		}
597 	}
598 
599 	if (default_acl_state.users->n || default_acl_state.groups->n) {
600 		default_acl_state.mask.allow = 0x07;
601 
602 		if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) {
603 			fattr->cf_dacls =
604 				posix_acl_alloc(default_acl_state.users->n +
605 				default_acl_state.groups->n + 4, KSMBD_DEFAULT_GFP);
606 			if (!fattr->cf_dacls) {
607 				ret = -ENOMEM;
608 				goto out;
609 			}
610 			cf_pdace = fattr->cf_dacls->a_entries;
611 			posix_state_to_acl(&default_acl_state, cf_pdace);
612 		}
613 	}
614 	ret = 0;
615 out:
616 	kfree(ppace);
617 	free_acl_state(&acl_state);
618 	free_acl_state(&default_acl_state);
619 	return ret;
620 }
621 
set_posix_acl_entries_dacl(struct mnt_idmap * idmap,struct smb_ace * pndace,struct smb_fattr * fattr,u16 * num_aces,u16 * size,u16 existing_nt_aces,bool had_nt_aces)622 static void set_posix_acl_entries_dacl(struct mnt_idmap *idmap,
623 				       struct smb_ace *pndace,
624 				       struct smb_fattr *fattr, u16 *num_aces,
625 				       u16 *size, u16 existing_nt_aces,
626 				       bool had_nt_aces)
627 {
628 	struct posix_acl_entry *pace;
629 	struct smb_sid *sid;
630 	struct smb_ace *ntace;
631 	int i, j;
632 	u16 ace_sz;
633 
634 	if (!fattr->cf_acls)
635 		goto posix_default_acl;
636 
637 	pace = fattr->cf_acls->a_entries;
638 	for (i = 0; i < fattr->cf_acls->a_count; i++, pace++) {
639 		int flags = 0;
640 
641 		sid = kmalloc_obj(struct smb_sid, KSMBD_DEFAULT_GFP);
642 		if (!sid)
643 			break;
644 
645 		if (pace->e_tag == ACL_USER) {
646 			uid_t uid;
647 			unsigned int sid_type = SIDOWNER;
648 
649 			uid = posix_acl_uid_translate(idmap, pace);
650 			if (!uid)
651 				sid_type = SIDUNIX_USER;
652 			id_to_sid(uid, sid_type, sid);
653 		} else if (pace->e_tag == ACL_GROUP) {
654 			gid_t gid;
655 
656 			gid = posix_acl_gid_translate(idmap, pace);
657 			id_to_sid(gid, SIDUNIX_GROUP, sid);
658 		} else if (pace->e_tag == ACL_OTHER && !had_nt_aces) {
659 			smb_copy_sid(sid, &sid_everyone);
660 		} else {
661 			kfree(sid);
662 			continue;
663 		}
664 		ntace = pndace;
665 		for (j = 0; j < existing_nt_aces; j++) {
666 			if (ntace->sid.sub_auth[ntace->sid.num_subauth - 1] ==
667 					sid->sub_auth[sid->num_subauth - 1])
668 				goto pass_same_sid;
669 			ntace = (struct smb_ace *)((char *)ntace +
670 					le16_to_cpu(ntace->size));
671 		}
672 
673 		if (S_ISDIR(fattr->cf_mode) && pace->e_tag == ACL_OTHER)
674 			flags = 0x03;
675 
676 		ntace = (struct smb_ace *)((char *)pndace + *size);
677 		ace_sz = fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED, flags,
678 				pace->e_perm, 0777);
679 		if (check_add_overflow(*size, ace_sz, size)) {
680 			*size -= ace_sz;
681 			kfree(sid);
682 			break;
683 		}
684 		(*num_aces)++;
685 		if (pace->e_tag == ACL_USER)
686 			ntace->access_req |=
687 				FILE_DELETE_LE | FILE_DELETE_CHILD_LE;
688 
689 		if (S_ISDIR(fattr->cf_mode) &&
690 		    (pace->e_tag == ACL_USER || pace->e_tag == ACL_GROUP)) {
691 			ntace = (struct smb_ace *)((char *)pndace + *size);
692 			ace_sz = fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED,
693 					0x03, pace->e_perm, 0777);
694 			if (check_add_overflow(*size, ace_sz, size)) {
695 				*size -= ace_sz;
696 				kfree(sid);
697 				break;
698 			}
699 			(*num_aces)++;
700 			if (pace->e_tag == ACL_USER)
701 				ntace->access_req |=
702 					FILE_DELETE_LE | FILE_DELETE_CHILD_LE;
703 		}
704 
705 pass_same_sid:
706 		kfree(sid);
707 	}
708 
709 	if (had_nt_aces)
710 		return;
711 
712 posix_default_acl:
713 	if (!fattr->cf_dacls)
714 		return;
715 
716 	pace = fattr->cf_dacls->a_entries;
717 	for (i = 0; i < fattr->cf_dacls->a_count; i++, pace++) {
718 		sid = kmalloc_obj(struct smb_sid, KSMBD_DEFAULT_GFP);
719 		if (!sid)
720 			break;
721 
722 		if (pace->e_tag == ACL_USER) {
723 			uid_t uid;
724 
725 			uid = posix_acl_uid_translate(idmap, pace);
726 			id_to_sid(uid, SIDCREATOR_OWNER, sid);
727 		} else if (pace->e_tag == ACL_GROUP) {
728 			gid_t gid;
729 
730 			gid = posix_acl_gid_translate(idmap, pace);
731 			id_to_sid(gid, SIDCREATOR_GROUP, sid);
732 		} else {
733 			kfree(sid);
734 			continue;
735 		}
736 
737 		ntace = (struct smb_ace *)((char *)pndace + *size);
738 		ace_sz = fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED, 0x0b,
739 				pace->e_perm, 0777);
740 		if (check_add_overflow(*size, ace_sz, size)) {
741 			*size -= ace_sz;
742 			kfree(sid);
743 			break;
744 		}
745 		(*num_aces)++;
746 		if (pace->e_tag == ACL_USER)
747 			ntace->access_req |=
748 				FILE_DELETE_LE | FILE_DELETE_CHILD_LE;
749 		kfree(sid);
750 	}
751 }
752 
set_ntacl_dacl(struct mnt_idmap * idmap,struct smb_acl * pndacl,struct smb_acl * nt_dacl,unsigned int aces_size,const struct smb_sid * pownersid,const struct smb_sid * pgrpsid,struct smb_fattr * fattr)753 static void set_ntacl_dacl(struct mnt_idmap *idmap,
754 			   struct smb_acl *pndacl,
755 			   struct smb_acl *nt_dacl,
756 			   unsigned int aces_size,
757 			   const struct smb_sid *pownersid,
758 			   const struct smb_sid *pgrpsid,
759 			   struct smb_fattr *fattr)
760 {
761 	struct smb_ace *ntace, *pndace;
762 	u16 nt_num_aces = le16_to_cpu(nt_dacl->num_aces), num_aces = 0;
763 	u16 copied_nt_aces;
764 	unsigned short size = 0;
765 	int i;
766 
767 	pndace = (struct smb_ace *)((char *)pndacl + sizeof(struct smb_acl));
768 	if (nt_num_aces) {
769 		ntace = (struct smb_ace *)((char *)nt_dacl + sizeof(struct smb_acl));
770 		for (i = 0; i < nt_num_aces; i++) {
771 			unsigned short nt_ace_size;
772 
773 			if (aces_size < offsetof(struct smb_ace, sid) +
774 					CIFS_SID_BASE_SIZE)
775 				break;
776 
777 			nt_ace_size = le16_to_cpu(ntace->size);
778 			if (nt_ace_size > aces_size ||
779 			    nt_ace_size < offsetof(struct smb_ace, sid) +
780 					  CIFS_SID_BASE_SIZE)
781 				break;
782 
783 			if (ntace->sid.num_subauth == 0 ||
784 			    ntace->sid.num_subauth > SID_MAX_SUB_AUTHORITIES ||
785 			    nt_ace_size < offsetof(struct smb_ace, sid) +
786 					  CIFS_SID_BASE_SIZE +
787 					  sizeof(__le32) *
788 					  ntace->sid.num_subauth)
789 				goto next_ace;
790 
791 			memcpy((char *)pndace + size, ntace, nt_ace_size);
792 			if (check_add_overflow(size, nt_ace_size, &size)) {
793 				size -= nt_ace_size;
794 				break;
795 			}
796 			num_aces++;
797 
798 next_ace:
799 			aces_size -= nt_ace_size;
800 			ntace = (struct smb_ace *)((char *)ntace + nt_ace_size);
801 		}
802 	}
803 
804 	copied_nt_aces = num_aces;
805 	set_posix_acl_entries_dacl(idmap, pndace, fattr,
806 				   &num_aces, &size, copied_nt_aces,
807 				   nt_num_aces != 0);
808 	pndacl->num_aces = cpu_to_le16(num_aces);
809 	pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size);
810 }
811 
set_mode_dacl(struct mnt_idmap * idmap,struct smb_acl * pndacl,struct smb_fattr * fattr)812 static void set_mode_dacl(struct mnt_idmap *idmap,
813 			  struct smb_acl *pndacl, struct smb_fattr *fattr)
814 {
815 	struct smb_ace *pace, *pndace;
816 	u16 num_aces = 0;
817 	u16 size = 0, ace_size = 0;
818 	uid_t uid;
819 	const struct smb_sid *sid;
820 
821 	pace = pndace = (struct smb_ace *)((char *)pndacl + sizeof(struct smb_acl));
822 
823 	if (fattr->cf_acls) {
824 		set_posix_acl_entries_dacl(idmap, pndace, fattr,
825 					   &num_aces, &size, num_aces, false);
826 		goto out;
827 	}
828 
829 	/* owner RID */
830 	uid = from_kuid(&init_user_ns, fattr->cf_uid);
831 	if (uid)
832 		sid = &server_conf.domain_sid;
833 	else
834 		sid = &sid_unix_users;
835 	ace_size = fill_ace_for_sid(pace, sid, ACCESS_ALLOWED, 0,
836 				    fattr->cf_mode, 0700);
837 	pace->sid.sub_auth[pace->sid.num_subauth++] = cpu_to_le32(uid);
838 	pace->size = cpu_to_le16(ace_size + 4);
839 	size += le16_to_cpu(pace->size);
840 	pace = (struct smb_ace *)((char *)pndace + size);
841 
842 	/* Group RID */
843 	ace_size = fill_ace_for_sid(pace, &sid_unix_groups,
844 				    ACCESS_ALLOWED, 0, fattr->cf_mode, 0070);
845 	pace->sid.sub_auth[pace->sid.num_subauth++] =
846 		cpu_to_le32(from_kgid(&init_user_ns, fattr->cf_gid));
847 	pace->size = cpu_to_le16(ace_size + 4);
848 	size += le16_to_cpu(pace->size);
849 	pace = (struct smb_ace *)((char *)pndace + size);
850 	num_aces = 3;
851 
852 	if (S_ISDIR(fattr->cf_mode)) {
853 		pace = (struct smb_ace *)((char *)pndace + size);
854 
855 		/* creator owner */
856 		size += fill_ace_for_sid(pace, &creator_owner, ACCESS_ALLOWED,
857 					 0x0b, fattr->cf_mode, 0700);
858 		pace = (struct smb_ace *)((char *)pndace + size);
859 
860 		/* creator group */
861 		size += fill_ace_for_sid(pace, &creator_group, ACCESS_ALLOWED,
862 					 0x0b, fattr->cf_mode, 0070);
863 		pace = (struct smb_ace *)((char *)pndace + size);
864 		num_aces = 5;
865 	}
866 
867 	/* other */
868 	size += fill_ace_for_sid(pace, &sid_everyone, ACCESS_ALLOWED, 0,
869 				 fattr->cf_mode, 0007);
870 
871 out:
872 	pndacl->num_aces = cpu_to_le16(num_aces);
873 	pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size);
874 }
875 
parse_sid(struct smb_sid * psid,char * end_of_acl)876 static int parse_sid(struct smb_sid *psid, char *end_of_acl)
877 {
878 	/*
879 	 * validate that we do not go past end of ACL - sid must be at least 8
880 	 * bytes long (assuming no sub-auths - e.g. the null SID
881 	 */
882 	if (end_of_acl < (char *)psid + 8) {
883 		pr_err("ACL too small to parse SID %p\n", psid);
884 		return -EINVAL;
885 	}
886 
887 	if (!psid->num_subauth)
888 		return 0;
889 
890 	if (psid->num_subauth > SID_MAX_SUB_AUTHORITIES ||
891 	    end_of_acl < (char *)psid + 8 + sizeof(__le32) * psid->num_subauth)
892 		return -EINVAL;
893 
894 	return 0;
895 }
896 
897 /* Convert CIFS ACL to POSIX form */
parse_sec_desc(struct mnt_idmap * idmap,struct smb_ntsd * pntsd,int acl_len,struct smb_fattr * fattr)898 int parse_sec_desc(struct mnt_idmap *idmap, struct smb_ntsd *pntsd,
899 		   int acl_len, struct smb_fattr *fattr)
900 {
901 	int rc = 0;
902 	struct smb_sid *owner_sid_ptr, *group_sid_ptr;
903 	struct smb_acl *dacl_ptr; /* no need for SACL ptr */
904 	char *end_of_acl = ((char *)pntsd) + acl_len;
905 	__u32 dacloffset;
906 	int pntsd_type;
907 
908 	if (!pntsd)
909 		return -EIO;
910 
911 	if (acl_len < sizeof(struct smb_ntsd))
912 		return -EINVAL;
913 
914 	owner_sid_ptr = (struct smb_sid *)((char *)pntsd +
915 			le32_to_cpu(pntsd->osidoffset));
916 	group_sid_ptr = (struct smb_sid *)((char *)pntsd +
917 			le32_to_cpu(pntsd->gsidoffset));
918 	dacloffset = le32_to_cpu(pntsd->dacloffset);
919 	dacl_ptr = (struct smb_acl *)((char *)pntsd + dacloffset);
920 	ksmbd_debug(SMB,
921 		    "revision %d type 0x%x ooffset 0x%x goffset 0x%x sacloffset 0x%x dacloffset 0x%x\n",
922 		    pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset),
923 		    le32_to_cpu(pntsd->gsidoffset),
924 		    le32_to_cpu(pntsd->sacloffset), dacloffset);
925 
926 	pntsd_type = le16_to_cpu(pntsd->type);
927 	if (!(pntsd_type & DACL_PRESENT)) {
928 		ksmbd_debug(SMB, "DACL_PRESENT in DACL type is not set\n");
929 		return rc;
930 	}
931 
932 	pntsd->type = cpu_to_le16(DACL_PRESENT);
933 
934 	if (pntsd->osidoffset) {
935 		if (le32_to_cpu(pntsd->osidoffset) < sizeof(struct smb_ntsd))
936 			return -EINVAL;
937 
938 		rc = parse_sid(owner_sid_ptr, end_of_acl);
939 		if (rc) {
940 			pr_err("%s: Error %d parsing Owner SID\n", __func__, rc);
941 			return rc;
942 		}
943 
944 		rc = sid_to_id(idmap, owner_sid_ptr, SIDOWNER, fattr);
945 		if (rc) {
946 			ksmbd_debug(SMB, "Owner SID has no Unix uid mapping\n");
947 			owner_sid_ptr = NULL;
948 			rc = 0;
949 		}
950 	}
951 
952 	if (pntsd->gsidoffset) {
953 		if (le32_to_cpu(pntsd->gsidoffset) < sizeof(struct smb_ntsd))
954 			return -EINVAL;
955 
956 		rc = parse_sid(group_sid_ptr, end_of_acl);
957 		if (rc) {
958 			pr_err("%s: Error %d mapping Owner SID to gid\n",
959 			       __func__, rc);
960 			return rc;
961 		}
962 		rc = sid_to_id(idmap, group_sid_ptr, SIDUNIX_GROUP, fattr);
963 		if (rc) {
964 			ksmbd_debug(SMB, "Group SID has no Unix gid mapping\n");
965 			group_sid_ptr = NULL;
966 			rc = 0;
967 		}
968 	}
969 
970 	if ((pntsd_type & (DACL_AUTO_INHERITED | DACL_AUTO_INHERIT_REQ)) ==
971 	    (DACL_AUTO_INHERITED | DACL_AUTO_INHERIT_REQ))
972 		pntsd->type |= cpu_to_le16(DACL_AUTO_INHERITED);
973 	if (pntsd_type & DACL_PROTECTED)
974 		pntsd->type |= cpu_to_le16(DACL_PROTECTED);
975 
976 	if (dacloffset) {
977 		if (dacloffset < sizeof(struct smb_ntsd))
978 			return -EINVAL;
979 
980 		rc = parse_dacl(idmap, dacl_ptr, end_of_acl,
981 				owner_sid_ptr, group_sid_ptr, fattr);
982 		if (rc)
983 			return rc;
984 	}
985 
986 	return 0;
987 }
988 
smb_acl_sec_desc_scratch_len(struct smb_fattr * fattr,struct smb_ntsd * ppntsd,int ppntsd_size,int addition_info)989 size_t smb_acl_sec_desc_scratch_len(struct smb_fattr *fattr,
990 		struct smb_ntsd *ppntsd, int ppntsd_size, int addition_info)
991 {
992 	size_t len = sizeof(struct smb_ntsd);
993 	size_t tmp;
994 
995 	if (addition_info & OWNER_SECINFO)
996 		len += sizeof(struct smb_sid);
997 	if (addition_info & GROUP_SECINFO)
998 		len += sizeof(struct smb_sid);
999 	if (!(addition_info & DACL_SECINFO))
1000 		return len;
1001 
1002 	len += sizeof(struct smb_acl);
1003 	if (ppntsd && ppntsd_size > 0) {
1004 		unsigned int dacl_offset = le32_to_cpu(ppntsd->dacloffset);
1005 
1006 		if (dacl_offset < ppntsd_size &&
1007 		    check_add_overflow(len, ppntsd_size - dacl_offset, &len))
1008 			return 0;
1009 	}
1010 
1011 	if (fattr->cf_acls) {
1012 		if (check_mul_overflow((size_t)fattr->cf_acls->a_count,
1013 					2 * sizeof(struct smb_ace), &tmp) ||
1014 		    check_add_overflow(len, tmp, &len))
1015 			return 0;
1016 	} else {
1017 		/* default/minimum DACL */
1018 		if (check_add_overflow(len, 5 * sizeof(struct smb_ace), &len))
1019 			return 0;
1020 	}
1021 
1022 	if (fattr->cf_dacls) {
1023 		if (check_mul_overflow((size_t)fattr->cf_dacls->a_count,
1024 					sizeof(struct smb_ace), &tmp) ||
1025 		    check_add_overflow(len, tmp, &len))
1026 			return 0;
1027 	}
1028 
1029 	return len;
1030 }
1031 
1032 /* Convert permission bits from mode to equivalent CIFS ACL */
build_sec_desc(struct mnt_idmap * idmap,struct smb_ntsd * pntsd,struct smb_ntsd * ppntsd,int ppntsd_size,int addition_info,__u32 * secdesclen,struct smb_fattr * fattr)1033 int build_sec_desc(struct mnt_idmap *idmap,
1034 		   struct smb_ntsd *pntsd, struct smb_ntsd *ppntsd,
1035 		   int ppntsd_size, int addition_info, __u32 *secdesclen,
1036 		   struct smb_fattr *fattr)
1037 {
1038 	int rc = 0;
1039 	__u32 offset;
1040 	struct smb_sid *owner_sid_ptr, *group_sid_ptr;
1041 	struct smb_sid *nowner_sid_ptr, *ngroup_sid_ptr;
1042 	struct smb_acl *dacl_ptr = NULL; /* no need for SACL ptr */
1043 	uid_t uid;
1044 	gid_t gid;
1045 	unsigned int sid_type = SIDOWNER;
1046 
1047 	nowner_sid_ptr = kmalloc_obj(struct smb_sid, KSMBD_DEFAULT_GFP);
1048 	if (!nowner_sid_ptr)
1049 		return -ENOMEM;
1050 
1051 	uid = from_kuid(&init_user_ns, fattr->cf_uid);
1052 	if (!uid)
1053 		sid_type = SIDUNIX_USER;
1054 	id_to_sid(uid, sid_type, nowner_sid_ptr);
1055 
1056 	ngroup_sid_ptr = kmalloc_obj(struct smb_sid, KSMBD_DEFAULT_GFP);
1057 	if (!ngroup_sid_ptr) {
1058 		kfree(nowner_sid_ptr);
1059 		return -ENOMEM;
1060 	}
1061 
1062 	gid = from_kgid(&init_user_ns, fattr->cf_gid);
1063 	id_to_sid(gid, SIDUNIX_GROUP, ngroup_sid_ptr);
1064 
1065 	offset = sizeof(struct smb_ntsd);
1066 	pntsd->sacloffset = 0;
1067 	pntsd->revision = cpu_to_le16(1);
1068 	pntsd->type = cpu_to_le16(SELF_RELATIVE);
1069 	if (ppntsd)
1070 		pntsd->type |= ppntsd->type;
1071 
1072 	if (addition_info & OWNER_SECINFO) {
1073 		pntsd->osidoffset = cpu_to_le32(offset);
1074 		owner_sid_ptr = (struct smb_sid *)((char *)pntsd + offset);
1075 		smb_copy_sid(owner_sid_ptr, nowner_sid_ptr);
1076 		offset += 1 + 1 + 6 + (nowner_sid_ptr->num_subauth * 4);
1077 	}
1078 
1079 	if (addition_info & GROUP_SECINFO) {
1080 		pntsd->gsidoffset = cpu_to_le32(offset);
1081 		group_sid_ptr = (struct smb_sid *)((char *)pntsd + offset);
1082 		smb_copy_sid(group_sid_ptr, ngroup_sid_ptr);
1083 		offset += 1 + 1 + 6 + (ngroup_sid_ptr->num_subauth * 4);
1084 	}
1085 
1086 	if (addition_info & DACL_SECINFO) {
1087 		pntsd->type |= cpu_to_le16(DACL_PRESENT);
1088 		dacl_ptr = (struct smb_acl *)((char *)pntsd + offset);
1089 		dacl_ptr->revision = cpu_to_le16(2);
1090 		dacl_ptr->size = cpu_to_le16(sizeof(struct smb_acl));
1091 		dacl_ptr->num_aces = 0;
1092 
1093 		if (!ppntsd) {
1094 			set_mode_dacl(idmap, dacl_ptr, fattr);
1095 		} else {
1096 			struct smb_acl *ppdacl_ptr;
1097 			unsigned int dacl_offset = le32_to_cpu(ppntsd->dacloffset);
1098 			int ppdacl_size, ntacl_size = ppntsd_size - dacl_offset;
1099 
1100 			if (!dacl_offset ||
1101 			    (dacl_offset + sizeof(struct smb_acl) > ppntsd_size))
1102 				goto out;
1103 
1104 			ppdacl_ptr = (struct smb_acl *)((char *)ppntsd + dacl_offset);
1105 			ppdacl_size = le16_to_cpu(ppdacl_ptr->size);
1106 			if (ppdacl_size > ntacl_size ||
1107 			    ppdacl_size < sizeof(struct smb_acl))
1108 				goto out;
1109 
1110 			set_ntacl_dacl(idmap, dacl_ptr, ppdacl_ptr,
1111 				       ntacl_size - sizeof(struct smb_acl),
1112 				       nowner_sid_ptr, ngroup_sid_ptr,
1113 				       fattr);
1114 		}
1115 		pntsd->dacloffset = cpu_to_le32(offset);
1116 		offset += le16_to_cpu(dacl_ptr->size);
1117 	}
1118 
1119 out:
1120 	kfree(nowner_sid_ptr);
1121 	kfree(ngroup_sid_ptr);
1122 	*secdesclen = offset;
1123 	return rc;
1124 }
1125 
smb_set_ace(struct smb_ace * ace,const struct smb_sid * sid,u8 type,u8 flags,__le32 access_req)1126 static void smb_set_ace(struct smb_ace *ace, const struct smb_sid *sid, u8 type,
1127 			u8 flags, __le32 access_req)
1128 {
1129 	ace->type = type;
1130 	ace->flags = flags;
1131 	ace->access_req = access_req;
1132 	smb_copy_sid(&ace->sid, sid);
1133 	ace->size = cpu_to_le16(1 + 1 + 2 + 4 + 1 + 1 + 6 +
1134 				(ace->sid.num_subauth * 4));
1135 }
1136 
smb_append_inherited_ace(struct smb_ace ** ace,int * nt_size,u16 * ace_cnt,const struct smb_sid * sid,u8 type,u8 flags,__le32 access_req)1137 static int smb_append_inherited_ace(struct smb_ace **ace, int *nt_size,
1138 				    u16 *ace_cnt, const struct smb_sid *sid,
1139 				    u8 type, u8 flags, __le32 access_req)
1140 {
1141 	int ace_size;
1142 
1143 	smb_set_ace(*ace, sid, type, flags, access_req);
1144 	ace_size = le16_to_cpu((*ace)->size);
1145 	/* pdacl->size is __le16 and includes struct smb_acl. */
1146 	if (check_add_overflow(*nt_size, ace_size, nt_size) ||
1147 	    *nt_size > U16_MAX - (int)sizeof(struct smb_acl))
1148 		return -EINVAL;
1149 
1150 	(*ace_cnt)++;
1151 	*ace = (struct smb_ace *)((char *)*ace + ace_size);
1152 	return 0;
1153 }
1154 
smb_validate_ntsd_sid(struct smb_ntsd * pntsd,size_t pntsd_size,unsigned int sid_offset,struct smb_sid ** sid,size_t * sid_size)1155 static int smb_validate_ntsd_sid(struct smb_ntsd *pntsd, size_t pntsd_size,
1156 				  unsigned int sid_offset, struct smb_sid **sid,
1157 				  size_t *sid_size)
1158 {
1159 	size_t sid_end;
1160 
1161 	*sid = NULL;
1162 	*sid_size = 0;
1163 
1164 	if (!sid_offset)
1165 		return 0;
1166 
1167 	if (sid_offset < sizeof(struct smb_ntsd) ||
1168 	    check_add_overflow(sid_offset, (size_t)CIFS_SID_BASE_SIZE,
1169 			       &sid_end) ||
1170 	    sid_end > pntsd_size)
1171 		return -EINVAL;
1172 
1173 	*sid = (struct smb_sid *)((char *)pntsd + sid_offset);
1174 	if ((*sid)->num_subauth > SID_MAX_SUB_AUTHORITIES)
1175 		return -EINVAL;
1176 
1177 	if (check_add_overflow((size_t)CIFS_SID_BASE_SIZE,
1178 			       sizeof(__le32) * (size_t)(*sid)->num_subauth,
1179 			       &sid_end))
1180 		return -EINVAL;
1181 
1182 	if (sid_offset > pntsd_size || sid_end > pntsd_size - sid_offset)
1183 		return -EINVAL;
1184 
1185 	*sid_size = sid_end;
1186 	return 0;
1187 }
1188 
smb_inherit_dacl(struct ksmbd_conn * conn,const struct path * path,unsigned int uid,unsigned int gid)1189 int smb_inherit_dacl(struct ksmbd_conn *conn,
1190 		     const struct path *path,
1191 		     unsigned int uid, unsigned int gid)
1192 {
1193 	const struct smb_sid *psid, *creator = NULL;
1194 	struct smb_ace *parent_aces, *aces;
1195 	struct smb_acl *parent_pdacl;
1196 	struct smb_ntsd *parent_pntsd = NULL;
1197 	struct smb_sid owner_sid, group_sid;
1198 	struct dentry *parent = path->dentry->d_parent;
1199 	struct mnt_idmap *idmap = mnt_idmap(path->mnt);
1200 	int inherited_flags = 0, flags = 0, i, nt_size = 0, pdacl_size;
1201 	int rc = 0, pntsd_type, ppntsd_size, acl_len, aces_size;
1202 	unsigned int dacloffset;
1203 	size_t dacl_struct_end;
1204 	u16 num_aces, ace_cnt = 0;
1205 	char *aces_base;
1206 	bool is_dir = S_ISDIR(d_inode(path->dentry)->i_mode);
1207 
1208 	ppntsd_size = ksmbd_vfs_get_sd_xattr(conn, idmap,
1209 					    parent, &parent_pntsd);
1210 	if (ppntsd_size <= 0)
1211 		return -ENOENT;
1212 
1213 	dacloffset = le32_to_cpu(parent_pntsd->dacloffset);
1214 	if (!dacloffset ||
1215 	    check_add_overflow(dacloffset, sizeof(struct smb_acl), &dacl_struct_end) ||
1216 	    dacl_struct_end > (size_t)ppntsd_size) {
1217 		rc = -EINVAL;
1218 		goto free_parent_pntsd;
1219 	}
1220 
1221 	parent_pdacl = (struct smb_acl *)((char *)parent_pntsd + dacloffset);
1222 	acl_len = ppntsd_size - dacloffset;
1223 	num_aces = le16_to_cpu(parent_pdacl->num_aces);
1224 	pntsd_type = le16_to_cpu(parent_pntsd->type);
1225 	pdacl_size = le16_to_cpu(parent_pdacl->size);
1226 
1227 	if (pdacl_size > acl_len || pdacl_size < sizeof(struct smb_acl)) {
1228 		rc = -EINVAL;
1229 		goto free_parent_pntsd;
1230 	}
1231 
1232 	aces_size = pdacl_size - sizeof(struct smb_acl);
1233 
1234 	/*
1235 	 * Validate num_aces against the DACL payload before allocating.
1236 	 * Each ACE must be at least as large as its fixed-size header
1237 	 * (up to the SID base), so num_aces cannot exceed the payload
1238 	 * divided by the minimum ACE size.  This mirrors the existing
1239 	 * check in parse_dacl().
1240 	 */
1241 	if (num_aces > aces_size / (offsetof(struct smb_ace, sid) +
1242 				    offsetof(struct smb_sid, sub_auth) +
1243 				    sizeof(__le16))) {
1244 		rc = -EINVAL;
1245 		goto free_parent_pntsd;
1246 	}
1247 
1248 	aces_base = kmalloc_array(num_aces * 2, sizeof(struct smb_ace),
1249 				  KSMBD_DEFAULT_GFP);
1250 	if (!aces_base) {
1251 		rc = -ENOMEM;
1252 		goto free_parent_pntsd;
1253 	}
1254 
1255 	aces = (struct smb_ace *)aces_base;
1256 	parent_aces = (struct smb_ace *)((char *)parent_pdacl +
1257 			sizeof(struct smb_acl));
1258 
1259 	if (pntsd_type & DACL_AUTO_INHERITED)
1260 		inherited_flags = INHERITED_ACE;
1261 
1262 	for (i = 0; i < num_aces; i++) {
1263 		int pace_size;
1264 
1265 		if (aces_size < offsetof(struct smb_ace, sid) +
1266 		    CIFS_SID_BASE_SIZE)
1267 			break;
1268 
1269 		pace_size = le16_to_cpu(parent_aces->size);
1270 		if (pace_size > aces_size ||
1271 		    pace_size < offsetof(struct smb_ace, sid) +
1272 				CIFS_SID_BASE_SIZE)
1273 			break;
1274 
1275 		if (parent_aces->sid.num_subauth > SID_MAX_SUB_AUTHORITIES ||
1276 		    pace_size < offsetof(struct smb_ace, sid) +
1277 				CIFS_SID_BASE_SIZE +
1278 				sizeof(__le32) * parent_aces->sid.num_subauth)
1279 			break;
1280 
1281 		aces_size -= pace_size;
1282 
1283 		flags = parent_aces->flags;
1284 		if (!smb_inherit_flags(flags, is_dir))
1285 			goto pass;
1286 		if (is_dir) {
1287 			flags &= ~(INHERIT_ONLY_ACE | INHERITED_ACE);
1288 			if (!(flags & CONTAINER_INHERIT_ACE))
1289 				flags |= INHERIT_ONLY_ACE;
1290 			if (flags & NO_PROPAGATE_INHERIT_ACE)
1291 				flags = 0;
1292 		} else {
1293 			flags = 0;
1294 		}
1295 
1296 		if (!compare_sids(&creator_owner, &parent_aces->sid)) {
1297 			creator = &creator_owner;
1298 			id_to_sid(uid, SIDOWNER, &owner_sid);
1299 			psid = &owner_sid;
1300 		} else if (!compare_sids(&creator_group, &parent_aces->sid)) {
1301 			creator = &creator_group;
1302 			id_to_sid(gid, SIDUNIX_GROUP, &group_sid);
1303 			psid = &group_sid;
1304 		} else {
1305 			creator = NULL;
1306 			psid = &parent_aces->sid;
1307 		}
1308 
1309 		if (is_dir && creator && flags & CONTAINER_INHERIT_ACE) {
1310 			rc = smb_append_inherited_ace(&aces, &nt_size, &ace_cnt,
1311 						      psid, parent_aces->type,
1312 						      inherited_flags,
1313 						      parent_aces->access_req);
1314 			if (rc)
1315 				goto free_aces_base;
1316 			flags |= INHERIT_ONLY_ACE;
1317 			psid = creator;
1318 		} else if (is_dir && !(parent_aces->flags & NO_PROPAGATE_INHERIT_ACE)) {
1319 			psid = &parent_aces->sid;
1320 		}
1321 
1322 		rc = smb_append_inherited_ace(&aces, &nt_size, &ace_cnt, psid,
1323 					      parent_aces->type,
1324 					      flags | inherited_flags,
1325 					      parent_aces->access_req);
1326 		if (rc)
1327 			goto free_aces_base;
1328 pass:
1329 		parent_aces = (struct smb_ace *)((char *)parent_aces + pace_size);
1330 	}
1331 
1332 	if (nt_size > 0) {
1333 		struct smb_ntsd *pntsd;
1334 		struct smb_acl *pdacl;
1335 		struct smb_sid *powner_sid = NULL, *pgroup_sid = NULL;
1336 		size_t powner_sid_size = 0, pgroup_sid_size = 0, pntsd_size;
1337 		size_t pntsd_alloc_size;
1338 
1339 		rc = smb_validate_ntsd_sid(parent_pntsd, ppntsd_size,
1340 					   le32_to_cpu(parent_pntsd->osidoffset),
1341 					   &powner_sid, &powner_sid_size);
1342 		if (rc)
1343 			goto free_aces_base;
1344 		rc = smb_validate_ntsd_sid(parent_pntsd, ppntsd_size,
1345 					   le32_to_cpu(parent_pntsd->gsidoffset),
1346 					   &pgroup_sid, &pgroup_sid_size);
1347 		if (rc)
1348 			goto free_aces_base;
1349 
1350 		if (check_add_overflow(sizeof(struct smb_ntsd),
1351 				       (size_t)powner_sid_size,
1352 				       &pntsd_alloc_size) ||
1353 		    check_add_overflow(pntsd_alloc_size,
1354 				       (size_t)pgroup_sid_size,
1355 				       &pntsd_alloc_size) ||
1356 		    check_add_overflow(pntsd_alloc_size, sizeof(struct smb_acl),
1357 				       &pntsd_alloc_size) ||
1358 		    check_add_overflow(pntsd_alloc_size, (size_t)nt_size,
1359 				       &pntsd_alloc_size)) {
1360 			rc = -EINVAL;
1361 			goto free_aces_base;
1362 		}
1363 
1364 		pntsd = kzalloc(pntsd_alloc_size, KSMBD_DEFAULT_GFP);
1365 		if (!pntsd) {
1366 			rc = -ENOMEM;
1367 			goto free_aces_base;
1368 		}
1369 
1370 		pntsd->revision = cpu_to_le16(1);
1371 		pntsd->type = cpu_to_le16(SELF_RELATIVE | DACL_PRESENT);
1372 		if (le16_to_cpu(parent_pntsd->type) & DACL_AUTO_INHERITED)
1373 			pntsd->type |= cpu_to_le16(DACL_AUTO_INHERITED);
1374 		pntsd_size = sizeof(struct smb_ntsd);
1375 		pntsd->osidoffset = parent_pntsd->osidoffset;
1376 		pntsd->gsidoffset = parent_pntsd->gsidoffset;
1377 		pntsd->dacloffset = parent_pntsd->dacloffset;
1378 
1379 		if ((u64)le32_to_cpu(pntsd->osidoffset) + powner_sid_size >
1380 		    pntsd_alloc_size) {
1381 			rc = -EINVAL;
1382 			kfree(pntsd);
1383 			goto free_aces_base;
1384 		}
1385 
1386 		if ((u64)le32_to_cpu(pntsd->gsidoffset) + pgroup_sid_size >
1387 		    pntsd_alloc_size) {
1388 			rc = -EINVAL;
1389 			kfree(pntsd);
1390 			goto free_aces_base;
1391 		}
1392 
1393 		if ((u64)le32_to_cpu(pntsd->dacloffset) + sizeof(struct smb_acl) + nt_size >
1394 		    pntsd_alloc_size) {
1395 			rc = -EINVAL;
1396 			kfree(pntsd);
1397 			goto free_aces_base;
1398 		}
1399 
1400 		if (pntsd->osidoffset) {
1401 			struct smb_sid *owner_sid = (struct smb_sid *)((char *)pntsd +
1402 					le32_to_cpu(pntsd->osidoffset));
1403 			memcpy(owner_sid, powner_sid, powner_sid_size);
1404 			pntsd_size += powner_sid_size;
1405 		}
1406 
1407 		if (pntsd->gsidoffset) {
1408 			struct smb_sid *group_sid = (struct smb_sid *)((char *)pntsd +
1409 					le32_to_cpu(pntsd->gsidoffset));
1410 			memcpy(group_sid, pgroup_sid, pgroup_sid_size);
1411 			pntsd_size += pgroup_sid_size;
1412 		}
1413 
1414 		if (pntsd->dacloffset) {
1415 			struct smb_ace *pace;
1416 
1417 			pdacl = (struct smb_acl *)((char *)pntsd + le32_to_cpu(pntsd->dacloffset));
1418 			pdacl->revision = cpu_to_le16(2);
1419 			pdacl->size = cpu_to_le16(sizeof(struct smb_acl) + nt_size);
1420 			pdacl->num_aces = cpu_to_le16(ace_cnt);
1421 			pace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl));
1422 			memcpy(pace, aces_base, nt_size);
1423 			pntsd_size += sizeof(struct smb_acl) + nt_size;
1424 		}
1425 
1426 		ksmbd_vfs_set_sd_xattr(conn, idmap, path, pntsd, pntsd_size, false);
1427 		kfree(pntsd);
1428 	}
1429 
1430 free_aces_base:
1431 	kfree(aces_base);
1432 free_parent_pntsd:
1433 	kfree(parent_pntsd);
1434 	return rc;
1435 }
1436 
smb_inherit_flags(int flags,bool is_dir)1437 bool smb_inherit_flags(int flags, bool is_dir)
1438 {
1439 	if (!is_dir)
1440 		return (flags & OBJECT_INHERIT_ACE) != 0;
1441 
1442 	if (flags & OBJECT_INHERIT_ACE && !(flags & NO_PROPAGATE_INHERIT_ACE))
1443 		return true;
1444 
1445 	if (flags & CONTAINER_INHERIT_ACE)
1446 		return true;
1447 	return false;
1448 }
1449 
smb_check_perm_dacl(struct ksmbd_conn * conn,const struct path * path,__le32 * pdaccess,__le32 raw_daccess,int uid,bool strict)1450 int smb_check_perm_dacl(struct ksmbd_conn *conn, const struct path *path,
1451 			__le32 *pdaccess, __le32 raw_daccess, int uid,
1452 			bool strict)
1453 {
1454 	struct mnt_idmap *idmap = mnt_idmap(path->mnt);
1455 	struct smb_ntsd *pntsd = NULL;
1456 	struct smb_acl *pdacl;
1457 	struct posix_acl *posix_acls;
1458 	int rc = 0, pntsd_size, acl_size, aces_size, pdacl_size;
1459 	unsigned int dacl_offset;
1460 	size_t dacl_struct_end;
1461 	struct smb_sid sid;
1462 	int requested = le32_to_cpu(*pdaccess & ~FILE_MAXIMAL_ACCESS_LE);
1463 	int granted = requested;
1464 	struct smb_ace *ace;
1465 	int i, found = 0;
1466 	unsigned int access_bits = 0, denied = 0;
1467 	struct smb_ace *others_ace = NULL;
1468 	struct posix_acl_entry *pa_entry;
1469 	unsigned int sid_type = SIDOWNER;
1470 	unsigned short ace_size;
1471 	bool is_owner, owner_rights = false;
1472 	vfsuid_t vfsuid;
1473 
1474 	ksmbd_debug(SMB, "check permission using windows acl\n");
1475 	pntsd_size = ksmbd_vfs_get_sd_xattr(conn, idmap,
1476 					    path->dentry, &pntsd);
1477 	if (pntsd_size <= 0 || !pntsd)
1478 		goto err_out;
1479 
1480 	dacl_offset = le32_to_cpu(pntsd->dacloffset);
1481 	if (!dacl_offset ||
1482 	    check_add_overflow(dacl_offset, sizeof(struct smb_acl), &dacl_struct_end) ||
1483 	    dacl_struct_end > (size_t)pntsd_size)
1484 		goto err_out;
1485 
1486 	pdacl = (struct smb_acl *)((char *)pntsd + le32_to_cpu(pntsd->dacloffset));
1487 	acl_size = pntsd_size - dacl_offset;
1488 	pdacl_size = le16_to_cpu(pdacl->size);
1489 
1490 	if (pdacl_size > acl_size || pdacl_size < sizeof(struct smb_acl))
1491 		goto err_out;
1492 
1493 	if (!pdacl->num_aces) {
1494 		if (!(pdacl_size - sizeof(struct smb_acl)) &&
1495 		    *pdaccess & ~(FILE_READ_CONTROL_LE | FILE_WRITE_DAC_LE)) {
1496 			rc = -EACCES;
1497 			goto err_out;
1498 		}
1499 		goto err_out;
1500 	}
1501 
1502 	if (!uid)
1503 		sid_type = SIDUNIX_USER;
1504 	id_to_sid(uid, sid_type, &sid);
1505 	vfsuid = i_uid_into_vfsuid(idmap, d_inode(path->dentry));
1506 	is_owner = uid == from_kuid(&init_user_ns, vfsuid_into_kuid(vfsuid));
1507 
1508 	if (*pdaccess & FILE_MAXIMAL_ACCESS_LE) {
1509 		ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl));
1510 		aces_size = pdacl_size - sizeof(struct smb_acl);
1511 		for (i = 0; i < le16_to_cpu(pdacl->num_aces); i++) {
1512 			if (aces_size < offsetof(struct smb_ace, sid) +
1513 			    CIFS_SID_BASE_SIZE)
1514 				break;
1515 			ace_size = le16_to_cpu(ace->size);
1516 			if (ace_size > aces_size ||
1517 			    ace_size < offsetof(struct smb_ace, sid) +
1518 				       CIFS_SID_BASE_SIZE)
1519 				break;
1520 			aces_size -= ace_size;
1521 
1522 			if (ace->sid.num_subauth > SID_MAX_SUB_AUTHORITIES ||
1523 			    ace_size < offsetof(struct smb_ace, sid) +
1524 				      CIFS_SID_BASE_SIZE +
1525 				      sizeof(__le32) * ace->sid.num_subauth)
1526 				break;
1527 
1528 			if (!compare_sids(&sid_owner_rights, &ace->sid)) {
1529 				owner_rights = true;
1530 				if (!is_owner)
1531 					goto next_ace;
1532 			}
1533 
1534 			if (ace->flags & INHERIT_ONLY_ACE ||
1535 			    (compare_sids(&sid, &ace->sid) &&
1536 			     compare_sids(&sid_unix_NFS_mode, &ace->sid) &&
1537 			     compare_sids(&sid_everyone, &ace->sid) &&
1538 			     compare_sids(&sid_authusers, &ace->sid) &&
1539 			     compare_sids(&sid_owner_rights, &ace->sid)))
1540 				goto next_ace;
1541 
1542 			switch (ace->type) {
1543 			case ACCESS_ALLOWED_ACE_TYPE:
1544 				access_bits |= le32_to_cpu(ace->access_req);
1545 				break;
1546 			case ACCESS_DENIED_ACE_TYPE:
1547 			case ACCESS_DENIED_CALLBACK_ACE_TYPE:
1548 				denied |= ~access_bits &
1549 					le32_to_cpu(ace->access_req);
1550 				break;
1551 			}
1552 next_ace:
1553 			ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size));
1554 		}
1555 		if (is_owner && !owner_rights)
1556 			access_bits |= READ_CONTROL | WRITE_DAC |
1557 				FILE_READ_ATTRIBUTES | DELETE;
1558 		access_bits &= ~denied;
1559 		if ((raw_daccess & FILE_GENERIC_EXECUTE_LE) &&
1560 		    S_ISREG(d_inode(path->dentry)->i_mode) &&
1561 		    (access_bits & GENERIC_READ_FLAGS) == GENERIC_READ_FLAGS)
1562 			access_bits |= FILE_EXECUTE;
1563 		granted = requested | access_bits;
1564 	}
1565 
1566 	ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl));
1567 	aces_size = pdacl_size - sizeof(struct smb_acl);
1568 	for (i = 0; i < le16_to_cpu(pdacl->num_aces); i++) {
1569 		if (aces_size < offsetof(struct smb_ace, sid) +
1570 		    CIFS_SID_BASE_SIZE)
1571 			break;
1572 		ace_size = le16_to_cpu(ace->size);
1573 		if (ace_size > aces_size ||
1574 		    ace_size < offsetof(struct smb_ace, sid) +
1575 			       CIFS_SID_BASE_SIZE)
1576 			break;
1577 		aces_size -= ace_size;
1578 
1579 		if (ace->sid.num_subauth > SID_MAX_SUB_AUTHORITIES ||
1580 		    ace_size < offsetof(struct smb_ace, sid) + CIFS_SID_BASE_SIZE +
1581 			      sizeof(__le32) * ace->sid.num_subauth)
1582 			break;
1583 
1584 		if (!compare_sids(&sid, &ace->sid) ||
1585 		    !compare_sids(&sid_unix_NFS_mode, &ace->sid)) {
1586 			found = 1;
1587 			break;
1588 		}
1589 		if (!compare_sids(&sid_everyone, &ace->sid) ||
1590 		    !compare_sids(&sid_authusers, &ace->sid))
1591 			others_ace = ace;
1592 
1593 		ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size));
1594 	}
1595 
1596 	if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) {
1597 		posix_acls = get_inode_acl(d_inode(path->dentry), ACL_TYPE_ACCESS);
1598 		if (!IS_ERR_OR_NULL(posix_acls) && !found && !others_ace) {
1599 			unsigned int id = -1;
1600 
1601 			pa_entry = posix_acls->a_entries;
1602 			for (i = 0; i < posix_acls->a_count; i++, pa_entry++) {
1603 				if (pa_entry->e_tag == ACL_USER)
1604 					id = posix_acl_uid_translate(idmap, pa_entry);
1605 				else if (pa_entry->e_tag == ACL_GROUP)
1606 					id = posix_acl_gid_translate(idmap, pa_entry);
1607 				else
1608 					continue;
1609 
1610 				if (id == uid) {
1611 					mode_to_access_flags(pa_entry->e_perm,
1612 							     0777,
1613 							     &access_bits);
1614 					if (!access_bits)
1615 						access_bits =
1616 							SET_MINIMUM_RIGHTS;
1617 					posix_acl_release(posix_acls);
1618 					goto check_access_bits;
1619 				}
1620 			}
1621 		}
1622 		if (!IS_ERR_OR_NULL(posix_acls))
1623 			posix_acl_release(posix_acls);
1624 	}
1625 
1626 	if (!found) {
1627 		if (others_ace) {
1628 			ace = others_ace;
1629 		} else {
1630 			ksmbd_debug(SMB, "Can't find corresponding sid\n");
1631 			rc = -EACCES;
1632 			goto err_out;
1633 		}
1634 	}
1635 
1636 	if (!(*pdaccess & FILE_MAXIMAL_ACCESS_LE)) {
1637 		switch (ace->type) {
1638 		case ACCESS_ALLOWED_ACE_TYPE:
1639 			access_bits = le32_to_cpu(ace->access_req);
1640 			break;
1641 		case ACCESS_DENIED_ACE_TYPE:
1642 		case ACCESS_DENIED_CALLBACK_ACE_TYPE:
1643 			access_bits = le32_to_cpu(~ace->access_req);
1644 			break;
1645 		}
1646 	}
1647 
1648 check_access_bits:
1649 	if (strict) {
1650 		access_bits &= granted;
1651 	} else {
1652 		access_bits |= FILE_READ_ATTRIBUTES | READ_CONTROL |
1653 			WRITE_DAC | DELETE;
1654 	}
1655 
1656 	if (granted & ~access_bits) {
1657 		ksmbd_debug(SMB, "Access denied with winACL, granted : %x, access_req : %x\n",
1658 			    granted, le32_to_cpu(ace->access_req));
1659 		rc = -EACCES;
1660 		goto err_out;
1661 	}
1662 
1663 	*pdaccess = cpu_to_le32(granted);
1664 err_out:
1665 	kfree(pntsd);
1666 	return rc;
1667 }
1668 
set_info_sec(struct ksmbd_conn * conn,struct ksmbd_tree_connect * tcon,const struct path * path,struct smb_ntsd * pntsd,int ntsd_len,bool type_check,bool get_write)1669 int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
1670 		 const struct path *path, struct smb_ntsd *pntsd, int ntsd_len,
1671 		 bool type_check, bool get_write)
1672 {
1673 	int rc;
1674 	struct smb_fattr fattr = {{0}};
1675 	struct inode *inode = d_inode(path->dentry);
1676 	struct mnt_idmap *idmap = mnt_idmap(path->mnt);
1677 	struct iattr newattrs;
1678 
1679 	fattr.cf_uid = INVALID_UID;
1680 	fattr.cf_gid = INVALID_GID;
1681 	fattr.cf_mode = inode->i_mode;
1682 
1683 	rc = parse_sec_desc(idmap, pntsd, ntsd_len, &fattr);
1684 	if (rc)
1685 		goto out;
1686 
1687 	newattrs.ia_valid = ATTR_CTIME;
1688 	if (!uid_eq(fattr.cf_uid, INVALID_UID)) {
1689 		newattrs.ia_valid |= ATTR_UID;
1690 		newattrs.ia_uid = fattr.cf_uid;
1691 	}
1692 	if (!gid_eq(fattr.cf_gid, INVALID_GID)) {
1693 		newattrs.ia_valid |= ATTR_GID;
1694 		newattrs.ia_gid = fattr.cf_gid;
1695 	}
1696 	newattrs.ia_valid |= ATTR_MODE;
1697 	newattrs.ia_mode = (inode->i_mode & ~0777) | (fattr.cf_mode & 0777);
1698 
1699 	ksmbd_vfs_remove_acl_xattrs(idmap, path);
1700 	/* Update posix acls */
1701 	if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && fattr.cf_dacls) {
1702 		rc = set_posix_acl(idmap, path->dentry,
1703 				   ACL_TYPE_ACCESS, fattr.cf_acls);
1704 		if (rc < 0)
1705 			ksmbd_debug(SMB,
1706 				    "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n",
1707 				    rc);
1708 		if (S_ISDIR(inode->i_mode) && fattr.cf_dacls) {
1709 			rc = set_posix_acl(idmap, path->dentry,
1710 					   ACL_TYPE_DEFAULT, fattr.cf_dacls);
1711 			if (rc)
1712 				ksmbd_debug(SMB,
1713 					    "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n",
1714 					    rc);
1715 		}
1716 	}
1717 
1718 	inode_lock(inode);
1719 	rc = notify_change(idmap, path->dentry, &newattrs, NULL);
1720 	inode_unlock(inode);
1721 	if (rc)
1722 		goto out;
1723 
1724 	/* Check it only calling from SD BUFFER context */
1725 	if (type_check && !(le16_to_cpu(pntsd->type) & DACL_PRESENT))
1726 		goto out;
1727 
1728 	if (test_share_config_flag(tcon->share_conf, KSMBD_SHARE_FLAG_ACL_XATTR)) {
1729 		/* Update WinACL in xattr */
1730 		ksmbd_vfs_remove_sd_xattrs(idmap, path);
1731 		ksmbd_vfs_set_sd_xattr(conn, idmap, path, pntsd, ntsd_len,
1732 				get_write);
1733 	}
1734 
1735 out:
1736 	posix_acl_release(fattr.cf_acls);
1737 	posix_acl_release(fattr.cf_dacls);
1738 	return rc;
1739 }
1740 
ksmbd_init_domain(u32 * sub_auth)1741 void ksmbd_init_domain(u32 *sub_auth)
1742 {
1743 	int i;
1744 
1745 	memcpy(&server_conf.domain_sid, &domain, sizeof(struct smb_sid));
1746 	for (i = 0; i < 3; ++i)
1747 		server_conf.domain_sid.sub_auth[i + 1] = cpu_to_le32(sub_auth[i]);
1748 }
1749