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 
13 #include "smbacl.h"
14 #include "smb_common.h"
15 #include "server.h"
16 #include "misc.h"
17 #include "mgmt/share_config.h"
18 
19 static const struct smb_sid domain = {1, 4, {0, 0, 0, 0, 0, 5},
20 	{cpu_to_le32(21), cpu_to_le32(1), cpu_to_le32(2), cpu_to_le32(3),
21 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
22 
23 /* security id for everyone/world system group */
24 static const struct smb_sid creator_owner = {
25 	1, 1, {0, 0, 0, 0, 0, 3}, {0} };
26 /* security id for everyone/world system group */
27 static const struct smb_sid creator_group = {
28 	1, 1, {0, 0, 0, 0, 0, 3}, {cpu_to_le32(1)} };
29 
30 /* security id for everyone/world system group */
31 static const struct smb_sid sid_everyone = {
32 	1, 1, {0, 0, 0, 0, 0, 1}, {0} };
33 /* security id for Authenticated Users system group */
34 static const struct smb_sid sid_authusers = {
35 	1, 1, {0, 0, 0, 0, 0, 5}, {cpu_to_le32(11)} };
36 
37 /* S-1-22-1 Unmapped Unix users */
38 static const struct smb_sid sid_unix_users = {1, 1, {0, 0, 0, 0, 0, 22},
39 		{cpu_to_le32(1), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
40 
41 /* S-1-22-2 Unmapped Unix groups */
42 static const struct smb_sid sid_unix_groups = { 1, 1, {0, 0, 0, 0, 0, 22},
43 		{cpu_to_le32(2), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
44 
45 /*
46  * See http://technet.microsoft.com/en-us/library/hh509017(v=ws.10).aspx
47  */
48 
49 /* S-1-5-88 MS NFS and Apple style UID/GID/mode */
50 
51 /* S-1-5-88-1 Unix uid */
52 static const struct smb_sid sid_unix_NFS_users = { 1, 2, {0, 0, 0, 0, 0, 5},
53 	{cpu_to_le32(88),
54 	 cpu_to_le32(1), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
55 
56 /* S-1-5-88-2 Unix gid */
57 static const struct smb_sid sid_unix_NFS_groups = { 1, 2, {0, 0, 0, 0, 0, 5},
58 	{cpu_to_le32(88),
59 	 cpu_to_le32(2), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
60 
61 /* S-1-5-88-3 Unix mode */
62 static const struct smb_sid sid_unix_NFS_mode = { 1, 2, {0, 0, 0, 0, 0, 5},
63 	{cpu_to_le32(88),
64 	 cpu_to_le32(3), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} };
65 
66 /*
67  * if the two SIDs (roughly equivalent to a UUID for a user or group) are
68  * the same returns zero, if they do not match returns non-zero.
69  */
compare_sids(const struct smb_sid * ctsid,const struct smb_sid * cwsid)70 int compare_sids(const struct smb_sid *ctsid, const struct smb_sid *cwsid)
71 {
72 	int i;
73 	int num_subauth, num_sat, num_saw;
74 
75 	if (!ctsid || !cwsid)
76 		return 1;
77 
78 	/* compare the revision */
79 	if (ctsid->revision != cwsid->revision) {
80 		if (ctsid->revision > cwsid->revision)
81 			return 1;
82 		else
83 			return -1;
84 	}
85 
86 	/* compare all of the six auth values */
87 	for (i = 0; i < NUM_AUTHS; ++i) {
88 		if (ctsid->authority[i] != cwsid->authority[i]) {
89 			if (ctsid->authority[i] > cwsid->authority[i])
90 				return 1;
91 			else
92 				return -1;
93 		}
94 	}
95 
96 	/* compare all of the subauth values if any */
97 	num_sat = ctsid->num_subauth;
98 	num_saw = cwsid->num_subauth;
99 	num_subauth = num_sat < num_saw ? num_sat : num_saw;
100 	if (num_subauth) {
101 		for (i = 0; i < num_subauth; ++i) {
102 			if (ctsid->sub_auth[i] != cwsid->sub_auth[i]) {
103 				if (le32_to_cpu(ctsid->sub_auth[i]) >
104 				    le32_to_cpu(cwsid->sub_auth[i]))
105 					return 1;
106 				else
107 					return -1;
108 			}
109 		}
110 	}
111 
112 	return 0; /* sids compare/match */
113 }
114 
smb_copy_sid(struct smb_sid * dst,const struct smb_sid * src)115 static void smb_copy_sid(struct smb_sid *dst, const struct smb_sid *src)
116 {
117 	int i;
118 
119 	dst->revision = src->revision;
120 	dst->num_subauth = min_t(u8, src->num_subauth, SID_MAX_SUB_AUTHORITIES);
121 	for (i = 0; i < NUM_AUTHS; ++i)
122 		dst->authority[i] = src->authority[i];
123 	for (i = 0; i < dst->num_subauth; ++i)
124 		dst->sub_auth[i] = src->sub_auth[i];
125 }
126 
127 /*
128  * change posix mode to reflect permissions
129  * pmode is the existing mode (we only want to overwrite part of this
130  * bits to set can be: S_IRWXU, S_IRWXG or S_IRWXO ie 00700 or 00070 or 00007
131  */
access_flags_to_mode(struct smb_fattr * fattr,__le32 ace_flags,int type)132 static umode_t access_flags_to_mode(struct smb_fattr *fattr, __le32 ace_flags,
133 				    int type)
134 {
135 	__u32 flags = le32_to_cpu(ace_flags);
136 	umode_t mode = 0;
137 
138 	if (flags & GENERIC_ALL) {
139 		mode = 0777;
140 		ksmbd_debug(SMB, "all perms\n");
141 		return mode;
142 	}
143 
144 	if ((flags & GENERIC_READ) || (flags & FILE_READ_RIGHTS))
145 		mode = 0444;
146 	if ((flags & GENERIC_WRITE) || (flags & FILE_WRITE_RIGHTS)) {
147 		mode |= 0222;
148 		if (S_ISDIR(fattr->cf_mode))
149 			mode |= 0111;
150 	}
151 	if ((flags & GENERIC_EXECUTE) || (flags & FILE_EXEC_RIGHTS))
152 		mode |= 0111;
153 
154 	if (type == ACCESS_DENIED_ACE_TYPE || type == ACCESS_DENIED_OBJECT_ACE_TYPE)
155 		mode = ~mode;
156 
157 	ksmbd_debug(SMB, "access flags 0x%x mode now %04o\n", flags, mode);
158 
159 	return mode;
160 }
161 
162 /*
163  * Generate access flags to reflect permissions mode is the existing mode.
164  * This function is called for every ACE in the DACL whose SID matches
165  * with either owner or group or everyone.
166  */
mode_to_access_flags(umode_t mode,umode_t bits_to_use,__u32 * pace_flags)167 static void mode_to_access_flags(umode_t mode, umode_t bits_to_use,
168 				 __u32 *pace_flags)
169 {
170 	/* reset access mask */
171 	*pace_flags = 0x0;
172 
173 	/* bits to use are either S_IRWXU or S_IRWXG or S_IRWXO */
174 	mode &= bits_to_use;
175 
176 	/*
177 	 * check for R/W/X UGO since we do not know whose flags
178 	 * is this but we have cleared all the bits sans RWX for
179 	 * either user or group or other as per bits_to_use
180 	 */
181 	if (mode & 0444)
182 		*pace_flags |= SET_FILE_READ_RIGHTS;
183 	if (mode & 0222)
184 		*pace_flags |= FILE_WRITE_RIGHTS;
185 	if (mode & 0111)
186 		*pace_flags |= SET_FILE_EXEC_RIGHTS;
187 
188 	ksmbd_debug(SMB, "mode: %o, access flags now 0x%x\n",
189 		    mode, *pace_flags);
190 }
191 
fill_ace_for_sid(struct smb_ace * pntace,const struct smb_sid * psid,int type,int flags,umode_t mode,umode_t bits)192 static __u16 fill_ace_for_sid(struct smb_ace *pntace,
193 			      const struct smb_sid *psid, int type, int flags,
194 			      umode_t mode, umode_t bits)
195 {
196 	int i;
197 	__u16 size = 0;
198 	__u32 access_req = 0;
199 
200 	pntace->type = type;
201 	pntace->flags = flags;
202 	mode_to_access_flags(mode, bits, &access_req);
203 	if (!access_req)
204 		access_req = SET_MINIMUM_RIGHTS;
205 	pntace->access_req = cpu_to_le32(access_req);
206 
207 	pntace->sid.revision = psid->revision;
208 	pntace->sid.num_subauth = psid->num_subauth;
209 	for (i = 0; i < NUM_AUTHS; i++)
210 		pntace->sid.authority[i] = psid->authority[i];
211 	for (i = 0; i < psid->num_subauth; i++)
212 		pntace->sid.sub_auth[i] = psid->sub_auth[i];
213 
214 	size = 1 + 1 + 2 + 4 + 1 + 1 + 6 + (psid->num_subauth * 4);
215 	pntace->size = cpu_to_le16(size);
216 
217 	return size;
218 }
219 
id_to_sid(unsigned int cid,uint sidtype,struct smb_sid * ssid)220 void id_to_sid(unsigned int cid, uint sidtype, struct smb_sid *ssid)
221 {
222 	switch (sidtype) {
223 	case SIDOWNER:
224 		smb_copy_sid(ssid, &server_conf.domain_sid);
225 		break;
226 	case SIDUNIX_USER:
227 		smb_copy_sid(ssid, &sid_unix_users);
228 		break;
229 	case SIDUNIX_GROUP:
230 		smb_copy_sid(ssid, &sid_unix_groups);
231 		break;
232 	case SIDCREATOR_OWNER:
233 		smb_copy_sid(ssid, &creator_owner);
234 		return;
235 	case SIDCREATOR_GROUP:
236 		smb_copy_sid(ssid, &creator_group);
237 		return;
238 	case SIDNFS_USER:
239 		smb_copy_sid(ssid, &sid_unix_NFS_users);
240 		break;
241 	case SIDNFS_GROUP:
242 		smb_copy_sid(ssid, &sid_unix_NFS_groups);
243 		break;
244 	case SIDNFS_MODE:
245 		smb_copy_sid(ssid, &sid_unix_NFS_mode);
246 		break;
247 	default:
248 		return;
249 	}
250 
251 	/* RID */
252 	ssid->sub_auth[ssid->num_subauth] = cpu_to_le32(cid);
253 	ssid->num_subauth++;
254 }
255 
sid_to_id(struct user_namespace * user_ns,struct smb_sid * psid,uint sidtype,struct smb_fattr * fattr)256 static int sid_to_id(struct user_namespace *user_ns,
257 		     struct smb_sid *psid, uint sidtype,
258 		     struct smb_fattr *fattr)
259 {
260 	int rc = -EINVAL;
261 
262 	/*
263 	 * If we have too many subauthorities, then something is really wrong.
264 	 * Just return an error.
265 	 */
266 	if (unlikely(psid->num_subauth > SID_MAX_SUB_AUTHORITIES)) {
267 		pr_err("%s: %u subauthorities is too many!\n",
268 		       __func__, psid->num_subauth);
269 		return -EIO;
270 	}
271 
272 	if (sidtype == SIDOWNER) {
273 		kuid_t uid;
274 		uid_t id;
275 
276 		id = le32_to_cpu(psid->sub_auth[psid->num_subauth - 1]);
277 		/*
278 		 * Translate raw sid into kuid in the server's user
279 		 * namespace.
280 		 */
281 		uid = make_kuid(&init_user_ns, id);
282 
283 		/* If this is an idmapped mount, apply the idmapping. */
284 		uid = kuid_from_mnt(user_ns, uid);
285 		if (uid_valid(uid)) {
286 			fattr->cf_uid = uid;
287 			rc = 0;
288 		}
289 	} else {
290 		kgid_t gid;
291 		gid_t id;
292 
293 		id = le32_to_cpu(psid->sub_auth[psid->num_subauth - 1]);
294 		/*
295 		 * Translate raw sid into kgid in the server's user
296 		 * namespace.
297 		 */
298 		gid = make_kgid(&init_user_ns, id);
299 
300 		/* If this is an idmapped mount, apply the idmapping. */
301 		gid = kgid_from_mnt(user_ns, gid);
302 		if (gid_valid(gid)) {
303 			fattr->cf_gid = gid;
304 			rc = 0;
305 		}
306 	}
307 
308 	return rc;
309 }
310 
posix_state_to_acl(struct posix_acl_state * state,struct posix_acl_entry * pace)311 void posix_state_to_acl(struct posix_acl_state *state,
312 			struct posix_acl_entry *pace)
313 {
314 	int i;
315 
316 	pace->e_tag = ACL_USER_OBJ;
317 	pace->e_perm = state->owner.allow;
318 	for (i = 0; i < state->users->n; i++) {
319 		pace++;
320 		pace->e_tag = ACL_USER;
321 		pace->e_uid = state->users->aces[i].uid;
322 		pace->e_perm = state->users->aces[i].perms.allow;
323 	}
324 
325 	pace++;
326 	pace->e_tag = ACL_GROUP_OBJ;
327 	pace->e_perm = state->group.allow;
328 
329 	for (i = 0; i < state->groups->n; i++) {
330 		pace++;
331 		pace->e_tag = ACL_GROUP;
332 		pace->e_gid = state->groups->aces[i].gid;
333 		pace->e_perm = state->groups->aces[i].perms.allow;
334 	}
335 
336 	if (state->users->n || state->groups->n) {
337 		pace++;
338 		pace->e_tag = ACL_MASK;
339 		pace->e_perm = state->mask.allow;
340 	}
341 
342 	pace++;
343 	pace->e_tag = ACL_OTHER;
344 	pace->e_perm = state->other.allow;
345 }
346 
init_acl_state(struct posix_acl_state * state,int cnt)347 int init_acl_state(struct posix_acl_state *state, int cnt)
348 {
349 	int alloc;
350 
351 	memset(state, 0, sizeof(struct posix_acl_state));
352 	/*
353 	 * In the worst case, each individual acl could be for a distinct
354 	 * named user or group, but we don't know which, so we allocate
355 	 * enough space for either:
356 	 */
357 	alloc = sizeof(struct posix_ace_state_array)
358 		+ cnt * sizeof(struct posix_user_ace_state);
359 	state->users = kzalloc(alloc, GFP_KERNEL);
360 	if (!state->users)
361 		return -ENOMEM;
362 	state->groups = kzalloc(alloc, GFP_KERNEL);
363 	if (!state->groups) {
364 		kfree(state->users);
365 		return -ENOMEM;
366 	}
367 	return 0;
368 }
369 
free_acl_state(struct posix_acl_state * state)370 void free_acl_state(struct posix_acl_state *state)
371 {
372 	kfree(state->users);
373 	kfree(state->groups);
374 }
375 
parse_dacl(struct user_namespace * user_ns,struct smb_acl * pdacl,char * end_of_acl,struct smb_sid * pownersid,struct smb_sid * pgrpsid,struct smb_fattr * fattr)376 static void parse_dacl(struct user_namespace *user_ns,
377 		       struct smb_acl *pdacl, char *end_of_acl,
378 		       struct smb_sid *pownersid, struct smb_sid *pgrpsid,
379 		       struct smb_fattr *fattr)
380 {
381 	int i, ret;
382 	int num_aces = 0;
383 	unsigned int acl_size;
384 	char *acl_base;
385 	struct smb_ace **ppace;
386 	struct posix_acl_entry *cf_pace, *cf_pdace;
387 	struct posix_acl_state acl_state, default_acl_state;
388 	umode_t mode = 0, acl_mode;
389 	bool owner_found = false, group_found = false, others_found = false;
390 
391 	if (!pdacl)
392 		return;
393 
394 	/* validate that we do not go past end of acl */
395 	if (end_of_acl < (char *)pdacl + sizeof(struct smb_acl) ||
396 	    end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) {
397 		pr_err("ACL too small to parse DACL\n");
398 		return;
399 	}
400 
401 	ksmbd_debug(SMB, "DACL revision %d size %d num aces %d\n",
402 		    le16_to_cpu(pdacl->revision), le16_to_cpu(pdacl->size),
403 		    le32_to_cpu(pdacl->num_aces));
404 
405 	acl_base = (char *)pdacl;
406 	acl_size = sizeof(struct smb_acl);
407 
408 	num_aces = le32_to_cpu(pdacl->num_aces);
409 	if (num_aces <= 0)
410 		return;
411 
412 	if (num_aces > ULONG_MAX / sizeof(struct smb_ace *))
413 		return;
414 
415 	ppace = kmalloc_array(num_aces, sizeof(struct smb_ace *), GFP_KERNEL);
416 	if (!ppace)
417 		return;
418 
419 	ret = init_acl_state(&acl_state, num_aces);
420 	if (ret)
421 		return;
422 	ret = init_acl_state(&default_acl_state, num_aces);
423 	if (ret) {
424 		free_acl_state(&acl_state);
425 		return;
426 	}
427 
428 	/*
429 	 * reset rwx permissions for user/group/other.
430 	 * Also, if num_aces is 0 i.e. DACL has no ACEs,
431 	 * user/group/other have no permissions
432 	 */
433 	for (i = 0; i < num_aces; ++i) {
434 		if (end_of_acl - acl_base < acl_size)
435 			break;
436 
437 		ppace[i] = (struct smb_ace *)(acl_base + acl_size);
438 		acl_base = (char *)ppace[i];
439 		acl_size = offsetof(struct smb_ace, sid) +
440 			offsetof(struct smb_sid, sub_auth);
441 
442 		if (end_of_acl - acl_base < acl_size ||
443 		    ppace[i]->sid.num_subauth > SID_MAX_SUB_AUTHORITIES ||
444 		    (end_of_acl - acl_base <
445 		     acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth) ||
446 		    (le16_to_cpu(ppace[i]->size) <
447 		     acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth))
448 			break;
449 
450 		acl_size = le16_to_cpu(ppace[i]->size);
451 		ppace[i]->access_req =
452 			smb_map_generic_desired_access(ppace[i]->access_req);
453 
454 		if (!(compare_sids(&ppace[i]->sid, &sid_unix_NFS_mode))) {
455 			fattr->cf_mode =
456 				le32_to_cpu(ppace[i]->sid.sub_auth[2]);
457 			break;
458 		} else if (!compare_sids(&ppace[i]->sid, pownersid)) {
459 			acl_mode = access_flags_to_mode(fattr,
460 							ppace[i]->access_req,
461 							ppace[i]->type);
462 			acl_mode &= 0700;
463 
464 			if (!owner_found) {
465 				mode &= ~(0700);
466 				mode |= acl_mode;
467 			}
468 			owner_found = true;
469 		} else if (!compare_sids(&ppace[i]->sid, pgrpsid) ||
470 			   ppace[i]->sid.sub_auth[ppace[i]->sid.num_subauth - 1] ==
471 			    DOMAIN_USER_RID_LE) {
472 			acl_mode = access_flags_to_mode(fattr,
473 							ppace[i]->access_req,
474 							ppace[i]->type);
475 			acl_mode &= 0070;
476 			if (!group_found) {
477 				mode &= ~(0070);
478 				mode |= acl_mode;
479 			}
480 			group_found = true;
481 		} else if (!compare_sids(&ppace[i]->sid, &sid_everyone)) {
482 			acl_mode = access_flags_to_mode(fattr,
483 							ppace[i]->access_req,
484 							ppace[i]->type);
485 			acl_mode &= 0007;
486 			if (!others_found) {
487 				mode &= ~(0007);
488 				mode |= acl_mode;
489 			}
490 			others_found = true;
491 		} else if (!compare_sids(&ppace[i]->sid, &creator_owner)) {
492 			continue;
493 		} else if (!compare_sids(&ppace[i]->sid, &creator_group)) {
494 			continue;
495 		} else if (!compare_sids(&ppace[i]->sid, &sid_authusers)) {
496 			continue;
497 		} else {
498 			struct smb_fattr temp_fattr;
499 
500 			acl_mode = access_flags_to_mode(fattr, ppace[i]->access_req,
501 							ppace[i]->type);
502 			temp_fattr.cf_uid = INVALID_UID;
503 			ret = sid_to_id(user_ns, &ppace[i]->sid, SIDOWNER, &temp_fattr);
504 			if (ret || uid_eq(temp_fattr.cf_uid, INVALID_UID)) {
505 				pr_err("%s: Error %d mapping Owner SID to uid\n",
506 				       __func__, ret);
507 				continue;
508 			}
509 
510 			acl_state.owner.allow = ((acl_mode & 0700) >> 6) | 0004;
511 			acl_state.users->aces[acl_state.users->n].uid =
512 				temp_fattr.cf_uid;
513 			acl_state.users->aces[acl_state.users->n++].perms.allow =
514 				((acl_mode & 0700) >> 6) | 0004;
515 			default_acl_state.owner.allow = ((acl_mode & 0700) >> 6) | 0004;
516 			default_acl_state.users->aces[default_acl_state.users->n].uid =
517 				temp_fattr.cf_uid;
518 			default_acl_state.users->aces[default_acl_state.users->n++].perms.allow =
519 				((acl_mode & 0700) >> 6) | 0004;
520 		}
521 	}
522 	kfree(ppace);
523 
524 	if (owner_found) {
525 		/* The owner must be set to at least read-only. */
526 		acl_state.owner.allow = ((mode & 0700) >> 6) | 0004;
527 		acl_state.users->aces[acl_state.users->n].uid = fattr->cf_uid;
528 		acl_state.users->aces[acl_state.users->n++].perms.allow =
529 			((mode & 0700) >> 6) | 0004;
530 		default_acl_state.owner.allow = ((mode & 0700) >> 6) | 0004;
531 		default_acl_state.users->aces[default_acl_state.users->n].uid =
532 			fattr->cf_uid;
533 		default_acl_state.users->aces[default_acl_state.users->n++].perms.allow =
534 			((mode & 0700) >> 6) | 0004;
535 	}
536 
537 	if (group_found) {
538 		acl_state.group.allow = (mode & 0070) >> 3;
539 		acl_state.groups->aces[acl_state.groups->n].gid =
540 			fattr->cf_gid;
541 		acl_state.groups->aces[acl_state.groups->n++].perms.allow =
542 			(mode & 0070) >> 3;
543 		default_acl_state.group.allow = (mode & 0070) >> 3;
544 		default_acl_state.groups->aces[default_acl_state.groups->n].gid =
545 			fattr->cf_gid;
546 		default_acl_state.groups->aces[default_acl_state.groups->n++].perms.allow =
547 			(mode & 0070) >> 3;
548 	}
549 
550 	if (others_found) {
551 		fattr->cf_mode &= ~(0007);
552 		fattr->cf_mode |= mode & 0007;
553 
554 		acl_state.other.allow = mode & 0007;
555 		default_acl_state.other.allow = mode & 0007;
556 	}
557 
558 	if (acl_state.users->n || acl_state.groups->n) {
559 		acl_state.mask.allow = 0x07;
560 
561 		if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) {
562 			fattr->cf_acls =
563 				posix_acl_alloc(acl_state.users->n +
564 					acl_state.groups->n + 4, GFP_KERNEL);
565 			if (fattr->cf_acls) {
566 				cf_pace = fattr->cf_acls->a_entries;
567 				posix_state_to_acl(&acl_state, cf_pace);
568 			}
569 		}
570 	}
571 
572 	if (default_acl_state.users->n || default_acl_state.groups->n) {
573 		default_acl_state.mask.allow = 0x07;
574 
575 		if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) {
576 			fattr->cf_dacls =
577 				posix_acl_alloc(default_acl_state.users->n +
578 				default_acl_state.groups->n + 4, GFP_KERNEL);
579 			if (fattr->cf_dacls) {
580 				cf_pdace = fattr->cf_dacls->a_entries;
581 				posix_state_to_acl(&default_acl_state, cf_pdace);
582 			}
583 		}
584 	}
585 	free_acl_state(&acl_state);
586 	free_acl_state(&default_acl_state);
587 }
588 
set_posix_acl_entries_dacl(struct user_namespace * user_ns,struct smb_ace * pndace,struct smb_fattr * fattr,u32 * num_aces,u16 * size,u32 nt_aces_num)589 static void set_posix_acl_entries_dacl(struct user_namespace *user_ns,
590 				       struct smb_ace *pndace,
591 				       struct smb_fattr *fattr, u32 *num_aces,
592 				       u16 *size, u32 nt_aces_num)
593 {
594 	struct posix_acl_entry *pace;
595 	struct smb_sid *sid;
596 	struct smb_ace *ntace;
597 	int i, j;
598 
599 	if (!fattr->cf_acls)
600 		goto posix_default_acl;
601 
602 	pace = fattr->cf_acls->a_entries;
603 	for (i = 0; i < fattr->cf_acls->a_count; i++, pace++) {
604 		int flags = 0;
605 
606 		sid = kmalloc(sizeof(struct smb_sid), GFP_KERNEL);
607 		if (!sid)
608 			break;
609 
610 		if (pace->e_tag == ACL_USER) {
611 			uid_t uid;
612 			unsigned int sid_type = SIDOWNER;
613 
614 			uid = posix_acl_uid_translate(user_ns, pace);
615 			if (!uid)
616 				sid_type = SIDUNIX_USER;
617 			id_to_sid(uid, sid_type, sid);
618 		} else if (pace->e_tag == ACL_GROUP) {
619 			gid_t gid;
620 
621 			gid = posix_acl_gid_translate(user_ns, pace);
622 			id_to_sid(gid, SIDUNIX_GROUP, sid);
623 		} else if (pace->e_tag == ACL_OTHER && !nt_aces_num) {
624 			smb_copy_sid(sid, &sid_everyone);
625 		} else {
626 			kfree(sid);
627 			continue;
628 		}
629 		ntace = pndace;
630 		for (j = 0; j < nt_aces_num; j++) {
631 			if (ntace->sid.sub_auth[ntace->sid.num_subauth - 1] ==
632 					sid->sub_auth[sid->num_subauth - 1])
633 				goto pass_same_sid;
634 			ntace = (struct smb_ace *)((char *)ntace +
635 					le16_to_cpu(ntace->size));
636 		}
637 
638 		if (S_ISDIR(fattr->cf_mode) && pace->e_tag == ACL_OTHER)
639 			flags = 0x03;
640 
641 		ntace = (struct smb_ace *)((char *)pndace + *size);
642 		*size += fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED, flags,
643 				pace->e_perm, 0777);
644 		(*num_aces)++;
645 		if (pace->e_tag == ACL_USER)
646 			ntace->access_req |=
647 				FILE_DELETE_LE | FILE_DELETE_CHILD_LE;
648 
649 		if (S_ISDIR(fattr->cf_mode) &&
650 		    (pace->e_tag == ACL_USER || pace->e_tag == ACL_GROUP)) {
651 			ntace = (struct smb_ace *)((char *)pndace + *size);
652 			*size += fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED,
653 					0x03, pace->e_perm, 0777);
654 			(*num_aces)++;
655 			if (pace->e_tag == ACL_USER)
656 				ntace->access_req |=
657 					FILE_DELETE_LE | FILE_DELETE_CHILD_LE;
658 		}
659 
660 pass_same_sid:
661 		kfree(sid);
662 	}
663 
664 	if (nt_aces_num)
665 		return;
666 
667 posix_default_acl:
668 	if (!fattr->cf_dacls)
669 		return;
670 
671 	pace = fattr->cf_dacls->a_entries;
672 	for (i = 0; i < fattr->cf_dacls->a_count; i++, pace++) {
673 		sid = kmalloc(sizeof(struct smb_sid), GFP_KERNEL);
674 		if (!sid)
675 			break;
676 
677 		if (pace->e_tag == ACL_USER) {
678 			uid_t uid;
679 
680 			uid = posix_acl_uid_translate(user_ns, pace);
681 			id_to_sid(uid, SIDCREATOR_OWNER, sid);
682 		} else if (pace->e_tag == ACL_GROUP) {
683 			gid_t gid;
684 
685 			gid = posix_acl_gid_translate(user_ns, pace);
686 			id_to_sid(gid, SIDCREATOR_GROUP, sid);
687 		} else {
688 			kfree(sid);
689 			continue;
690 		}
691 
692 		ntace = (struct smb_ace *)((char *)pndace + *size);
693 		*size += fill_ace_for_sid(ntace, sid, ACCESS_ALLOWED, 0x0b,
694 				pace->e_perm, 0777);
695 		(*num_aces)++;
696 		if (pace->e_tag == ACL_USER)
697 			ntace->access_req |=
698 				FILE_DELETE_LE | FILE_DELETE_CHILD_LE;
699 		kfree(sid);
700 	}
701 }
702 
set_ntacl_dacl(struct user_namespace * user_ns,struct smb_acl * pndacl,struct smb_acl * nt_dacl,const struct smb_sid * pownersid,const struct smb_sid * pgrpsid,struct smb_fattr * fattr)703 static void set_ntacl_dacl(struct user_namespace *user_ns,
704 			   struct smb_acl *pndacl,
705 			   struct smb_acl *nt_dacl,
706 			   const struct smb_sid *pownersid,
707 			   const struct smb_sid *pgrpsid,
708 			   struct smb_fattr *fattr)
709 {
710 	struct smb_ace *ntace, *pndace;
711 	int nt_num_aces = le32_to_cpu(nt_dacl->num_aces), num_aces = 0;
712 	unsigned short size = 0;
713 	int i;
714 
715 	pndace = (struct smb_ace *)((char *)pndacl + sizeof(struct smb_acl));
716 	if (nt_num_aces) {
717 		ntace = (struct smb_ace *)((char *)nt_dacl + sizeof(struct smb_acl));
718 		for (i = 0; i < nt_num_aces; i++) {
719 			memcpy((char *)pndace + size, ntace, le16_to_cpu(ntace->size));
720 			size += le16_to_cpu(ntace->size);
721 			ntace = (struct smb_ace *)((char *)ntace + le16_to_cpu(ntace->size));
722 			num_aces++;
723 		}
724 	}
725 
726 	set_posix_acl_entries_dacl(user_ns, pndace, fattr,
727 				   &num_aces, &size, nt_num_aces);
728 	pndacl->num_aces = cpu_to_le32(num_aces);
729 	pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size);
730 }
731 
set_mode_dacl(struct user_namespace * user_ns,struct smb_acl * pndacl,struct smb_fattr * fattr)732 static void set_mode_dacl(struct user_namespace *user_ns,
733 			  struct smb_acl *pndacl, struct smb_fattr *fattr)
734 {
735 	struct smb_ace *pace, *pndace;
736 	u32 num_aces = 0;
737 	u16 size = 0, ace_size = 0;
738 	uid_t uid;
739 	const struct smb_sid *sid;
740 
741 	pace = pndace = (struct smb_ace *)((char *)pndacl + sizeof(struct smb_acl));
742 
743 	if (fattr->cf_acls) {
744 		set_posix_acl_entries_dacl(user_ns, pndace, fattr,
745 					   &num_aces, &size, num_aces);
746 		goto out;
747 	}
748 
749 	/* owner RID */
750 	uid = from_kuid(&init_user_ns, fattr->cf_uid);
751 	if (uid)
752 		sid = &server_conf.domain_sid;
753 	else
754 		sid = &sid_unix_users;
755 	ace_size = fill_ace_for_sid(pace, sid, ACCESS_ALLOWED, 0,
756 				    fattr->cf_mode, 0700);
757 	pace->sid.sub_auth[pace->sid.num_subauth++] = cpu_to_le32(uid);
758 	pace->size = cpu_to_le16(ace_size + 4);
759 	size += le16_to_cpu(pace->size);
760 	pace = (struct smb_ace *)((char *)pndace + size);
761 
762 	/* Group RID */
763 	ace_size = fill_ace_for_sid(pace, &sid_unix_groups,
764 				    ACCESS_ALLOWED, 0, fattr->cf_mode, 0070);
765 	pace->sid.sub_auth[pace->sid.num_subauth++] =
766 		cpu_to_le32(from_kgid(&init_user_ns, fattr->cf_gid));
767 	pace->size = cpu_to_le16(ace_size + 4);
768 	size += le16_to_cpu(pace->size);
769 	pace = (struct smb_ace *)((char *)pndace + size);
770 	num_aces = 3;
771 
772 	if (S_ISDIR(fattr->cf_mode)) {
773 		pace = (struct smb_ace *)((char *)pndace + size);
774 
775 		/* creator owner */
776 		size += fill_ace_for_sid(pace, &creator_owner, ACCESS_ALLOWED,
777 					 0x0b, fattr->cf_mode, 0700);
778 		pace = (struct smb_ace *)((char *)pndace + size);
779 
780 		/* creator group */
781 		size += fill_ace_for_sid(pace, &creator_group, ACCESS_ALLOWED,
782 					 0x0b, fattr->cf_mode, 0070);
783 		pace = (struct smb_ace *)((char *)pndace + size);
784 		num_aces = 5;
785 	}
786 
787 	/* other */
788 	size += fill_ace_for_sid(pace, &sid_everyone, ACCESS_ALLOWED, 0,
789 				 fattr->cf_mode, 0007);
790 
791 out:
792 	pndacl->num_aces = cpu_to_le32(num_aces);
793 	pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size);
794 }
795 
parse_sid(struct smb_sid * psid,char * end_of_acl)796 static int parse_sid(struct smb_sid *psid, char *end_of_acl)
797 {
798 	/*
799 	 * validate that we do not go past end of ACL - sid must be at least 8
800 	 * bytes long (assuming no sub-auths - e.g. the null SID
801 	 */
802 	if (end_of_acl < (char *)psid + 8) {
803 		pr_err("ACL too small to parse SID %p\n", psid);
804 		return -EINVAL;
805 	}
806 
807 	return 0;
808 }
809 
810 /* Convert CIFS ACL to POSIX form */
parse_sec_desc(struct user_namespace * user_ns,struct smb_ntsd * pntsd,int acl_len,struct smb_fattr * fattr)811 int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
812 		   int acl_len, struct smb_fattr *fattr)
813 {
814 	int rc = 0;
815 	struct smb_sid *owner_sid_ptr, *group_sid_ptr;
816 	struct smb_acl *dacl_ptr; /* no need for SACL ptr */
817 	char *end_of_acl = ((char *)pntsd) + acl_len;
818 	__u32 dacloffset;
819 	int pntsd_type;
820 
821 	if (!pntsd)
822 		return -EIO;
823 
824 	if (acl_len < sizeof(struct smb_ntsd))
825 		return -EINVAL;
826 
827 	owner_sid_ptr = (struct smb_sid *)((char *)pntsd +
828 			le32_to_cpu(pntsd->osidoffset));
829 	group_sid_ptr = (struct smb_sid *)((char *)pntsd +
830 			le32_to_cpu(pntsd->gsidoffset));
831 	dacloffset = le32_to_cpu(pntsd->dacloffset);
832 	dacl_ptr = (struct smb_acl *)((char *)pntsd + dacloffset);
833 	ksmbd_debug(SMB,
834 		    "revision %d type 0x%x ooffset 0x%x goffset 0x%x sacloffset 0x%x dacloffset 0x%x\n",
835 		    pntsd->revision, pntsd->type, le32_to_cpu(pntsd->osidoffset),
836 		    le32_to_cpu(pntsd->gsidoffset),
837 		    le32_to_cpu(pntsd->sacloffset), dacloffset);
838 
839 	pntsd_type = le16_to_cpu(pntsd->type);
840 	if (!(pntsd_type & DACL_PRESENT)) {
841 		ksmbd_debug(SMB, "DACL_PRESENT in DACL type is not set\n");
842 		return rc;
843 	}
844 
845 	pntsd->type = cpu_to_le16(DACL_PRESENT);
846 
847 	if (pntsd->osidoffset) {
848 		rc = parse_sid(owner_sid_ptr, end_of_acl);
849 		if (rc) {
850 			pr_err("%s: Error %d parsing Owner SID\n", __func__, rc);
851 			return rc;
852 		}
853 
854 		rc = sid_to_id(user_ns, owner_sid_ptr, SIDOWNER, fattr);
855 		if (rc) {
856 			pr_err("%s: Error %d mapping Owner SID to uid\n",
857 			       __func__, rc);
858 			owner_sid_ptr = NULL;
859 		}
860 	}
861 
862 	if (pntsd->gsidoffset) {
863 		rc = parse_sid(group_sid_ptr, end_of_acl);
864 		if (rc) {
865 			pr_err("%s: Error %d mapping Owner SID to gid\n",
866 			       __func__, rc);
867 			return rc;
868 		}
869 		rc = sid_to_id(user_ns, group_sid_ptr, SIDUNIX_GROUP, fattr);
870 		if (rc) {
871 			pr_err("%s: Error %d mapping Group SID to gid\n",
872 			       __func__, rc);
873 			group_sid_ptr = NULL;
874 		}
875 	}
876 
877 	if ((pntsd_type & (DACL_AUTO_INHERITED | DACL_AUTO_INHERIT_REQ)) ==
878 	    (DACL_AUTO_INHERITED | DACL_AUTO_INHERIT_REQ))
879 		pntsd->type |= cpu_to_le16(DACL_AUTO_INHERITED);
880 	if (pntsd_type & DACL_PROTECTED)
881 		pntsd->type |= cpu_to_le16(DACL_PROTECTED);
882 
883 	if (dacloffset) {
884 		parse_dacl(user_ns, dacl_ptr, end_of_acl,
885 			   owner_sid_ptr, group_sid_ptr, fattr);
886 	}
887 
888 	return 0;
889 }
890 
891 /* Convert permission bits from mode to equivalent CIFS ACL */
build_sec_desc(struct user_namespace * user_ns,struct smb_ntsd * pntsd,struct smb_ntsd * ppntsd,int addition_info,__u32 * secdesclen,struct smb_fattr * fattr)892 int build_sec_desc(struct user_namespace *user_ns,
893 		   struct smb_ntsd *pntsd, struct smb_ntsd *ppntsd,
894 		   int addition_info, __u32 *secdesclen,
895 		   struct smb_fattr *fattr)
896 {
897 	int rc = 0;
898 	__u32 offset;
899 	struct smb_sid *owner_sid_ptr, *group_sid_ptr;
900 	struct smb_sid *nowner_sid_ptr, *ngroup_sid_ptr;
901 	struct smb_acl *dacl_ptr = NULL; /* no need for SACL ptr */
902 	uid_t uid;
903 	gid_t gid;
904 	unsigned int sid_type = SIDOWNER;
905 
906 	nowner_sid_ptr = kmalloc(sizeof(struct smb_sid), GFP_KERNEL);
907 	if (!nowner_sid_ptr)
908 		return -ENOMEM;
909 
910 	uid = from_kuid(&init_user_ns, fattr->cf_uid);
911 	if (!uid)
912 		sid_type = SIDUNIX_USER;
913 	id_to_sid(uid, sid_type, nowner_sid_ptr);
914 
915 	ngroup_sid_ptr = kmalloc(sizeof(struct smb_sid), GFP_KERNEL);
916 	if (!ngroup_sid_ptr) {
917 		kfree(nowner_sid_ptr);
918 		return -ENOMEM;
919 	}
920 
921 	gid = from_kgid(&init_user_ns, fattr->cf_gid);
922 	id_to_sid(gid, SIDUNIX_GROUP, ngroup_sid_ptr);
923 
924 	offset = sizeof(struct smb_ntsd);
925 	pntsd->sacloffset = 0;
926 	pntsd->revision = cpu_to_le16(1);
927 	pntsd->type = cpu_to_le16(SELF_RELATIVE);
928 	if (ppntsd)
929 		pntsd->type |= ppntsd->type;
930 
931 	if (addition_info & OWNER_SECINFO) {
932 		pntsd->osidoffset = cpu_to_le32(offset);
933 		owner_sid_ptr = (struct smb_sid *)((char *)pntsd + offset);
934 		smb_copy_sid(owner_sid_ptr, nowner_sid_ptr);
935 		offset += 1 + 1 + 6 + (nowner_sid_ptr->num_subauth * 4);
936 	}
937 
938 	if (addition_info & GROUP_SECINFO) {
939 		pntsd->gsidoffset = cpu_to_le32(offset);
940 		group_sid_ptr = (struct smb_sid *)((char *)pntsd + offset);
941 		smb_copy_sid(group_sid_ptr, ngroup_sid_ptr);
942 		offset += 1 + 1 + 6 + (ngroup_sid_ptr->num_subauth * 4);
943 	}
944 
945 	if (addition_info & DACL_SECINFO) {
946 		pntsd->type |= cpu_to_le16(DACL_PRESENT);
947 		dacl_ptr = (struct smb_acl *)((char *)pntsd + offset);
948 		dacl_ptr->revision = cpu_to_le16(2);
949 		dacl_ptr->size = cpu_to_le16(sizeof(struct smb_acl));
950 		dacl_ptr->num_aces = 0;
951 
952 		if (!ppntsd) {
953 			set_mode_dacl(user_ns, dacl_ptr, fattr);
954 		} else if (!ppntsd->dacloffset) {
955 			goto out;
956 		} else {
957 			struct smb_acl *ppdacl_ptr;
958 
959 			ppdacl_ptr = (struct smb_acl *)((char *)ppntsd +
960 						le32_to_cpu(ppntsd->dacloffset));
961 			set_ntacl_dacl(user_ns, dacl_ptr, ppdacl_ptr,
962 				       nowner_sid_ptr, ngroup_sid_ptr, fattr);
963 		}
964 		pntsd->dacloffset = cpu_to_le32(offset);
965 		offset += le16_to_cpu(dacl_ptr->size);
966 	}
967 
968 out:
969 	kfree(nowner_sid_ptr);
970 	kfree(ngroup_sid_ptr);
971 	*secdesclen = offset;
972 	return rc;
973 }
974 
smb_set_ace(struct smb_ace * ace,const struct smb_sid * sid,u8 type,u8 flags,__le32 access_req)975 static void smb_set_ace(struct smb_ace *ace, const struct smb_sid *sid, u8 type,
976 			u8 flags, __le32 access_req)
977 {
978 	ace->type = type;
979 	ace->flags = flags;
980 	ace->access_req = access_req;
981 	smb_copy_sid(&ace->sid, sid);
982 	ace->size = cpu_to_le16(1 + 1 + 2 + 4 + 1 + 1 + 6 + (sid->num_subauth * 4));
983 }
984 
smb_inherit_dacl(struct ksmbd_conn * conn,struct path * path,unsigned int uid,unsigned int gid)985 int smb_inherit_dacl(struct ksmbd_conn *conn,
986 		     struct path *path,
987 		     unsigned int uid, unsigned int gid)
988 {
989 	const struct smb_sid *psid, *creator = NULL;
990 	struct smb_ace *parent_aces, *aces;
991 	struct smb_acl *parent_pdacl;
992 	struct smb_ntsd *parent_pntsd = NULL;
993 	struct smb_sid owner_sid, group_sid;
994 	struct dentry *parent = path->dentry->d_parent;
995 	struct user_namespace *user_ns = mnt_user_ns(path->mnt);
996 	int inherited_flags = 0, flags = 0, i, ace_cnt = 0, nt_size = 0;
997 	int rc = 0, num_aces, dacloffset, pntsd_type, acl_len;
998 	char *aces_base;
999 	bool is_dir = S_ISDIR(d_inode(path->dentry)->i_mode);
1000 
1001 	acl_len = ksmbd_vfs_get_sd_xattr(conn, user_ns,
1002 					 parent, &parent_pntsd);
1003 	if (acl_len <= 0)
1004 		return -ENOENT;
1005 	dacloffset = le32_to_cpu(parent_pntsd->dacloffset);
1006 	if (!dacloffset) {
1007 		rc = -EINVAL;
1008 		goto free_parent_pntsd;
1009 	}
1010 
1011 	parent_pdacl = (struct smb_acl *)((char *)parent_pntsd + dacloffset);
1012 	num_aces = le32_to_cpu(parent_pdacl->num_aces);
1013 	pntsd_type = le16_to_cpu(parent_pntsd->type);
1014 
1015 	aces_base = kmalloc(sizeof(struct smb_ace) * num_aces * 2, GFP_KERNEL);
1016 	if (!aces_base) {
1017 		rc = -ENOMEM;
1018 		goto free_parent_pntsd;
1019 	}
1020 
1021 	aces = (struct smb_ace *)aces_base;
1022 	parent_aces = (struct smb_ace *)((char *)parent_pdacl +
1023 			sizeof(struct smb_acl));
1024 
1025 	if (pntsd_type & DACL_AUTO_INHERITED)
1026 		inherited_flags = INHERITED_ACE;
1027 
1028 	for (i = 0; i < num_aces; i++) {
1029 		flags = parent_aces->flags;
1030 		if (!smb_inherit_flags(flags, is_dir))
1031 			goto pass;
1032 		if (is_dir) {
1033 			flags &= ~(INHERIT_ONLY_ACE | INHERITED_ACE);
1034 			if (!(flags & CONTAINER_INHERIT_ACE))
1035 				flags |= INHERIT_ONLY_ACE;
1036 			if (flags & NO_PROPAGATE_INHERIT_ACE)
1037 				flags = 0;
1038 		} else {
1039 			flags = 0;
1040 		}
1041 
1042 		if (!compare_sids(&creator_owner, &parent_aces->sid)) {
1043 			creator = &creator_owner;
1044 			id_to_sid(uid, SIDOWNER, &owner_sid);
1045 			psid = &owner_sid;
1046 		} else if (!compare_sids(&creator_group, &parent_aces->sid)) {
1047 			creator = &creator_group;
1048 			id_to_sid(gid, SIDUNIX_GROUP, &group_sid);
1049 			psid = &group_sid;
1050 		} else {
1051 			creator = NULL;
1052 			psid = &parent_aces->sid;
1053 		}
1054 
1055 		if (is_dir && creator && flags & CONTAINER_INHERIT_ACE) {
1056 			smb_set_ace(aces, psid, parent_aces->type, inherited_flags,
1057 				    parent_aces->access_req);
1058 			nt_size += le16_to_cpu(aces->size);
1059 			ace_cnt++;
1060 			aces = (struct smb_ace *)((char *)aces + le16_to_cpu(aces->size));
1061 			flags |= INHERIT_ONLY_ACE;
1062 			psid = creator;
1063 		} else if (is_dir && !(parent_aces->flags & NO_PROPAGATE_INHERIT_ACE)) {
1064 			psid = &parent_aces->sid;
1065 		}
1066 
1067 		smb_set_ace(aces, psid, parent_aces->type, flags | inherited_flags,
1068 			    parent_aces->access_req);
1069 		nt_size += le16_to_cpu(aces->size);
1070 		aces = (struct smb_ace *)((char *)aces + le16_to_cpu(aces->size));
1071 		ace_cnt++;
1072 pass:
1073 		parent_aces =
1074 			(struct smb_ace *)((char *)parent_aces + le16_to_cpu(parent_aces->size));
1075 	}
1076 
1077 	if (nt_size > 0) {
1078 		struct smb_ntsd *pntsd;
1079 		struct smb_acl *pdacl;
1080 		struct smb_sid *powner_sid = NULL, *pgroup_sid = NULL;
1081 		int powner_sid_size = 0, pgroup_sid_size = 0, pntsd_size;
1082 
1083 		if (parent_pntsd->osidoffset) {
1084 			powner_sid = (struct smb_sid *)((char *)parent_pntsd +
1085 					le32_to_cpu(parent_pntsd->osidoffset));
1086 			powner_sid_size = 1 + 1 + 6 + (powner_sid->num_subauth * 4);
1087 		}
1088 		if (parent_pntsd->gsidoffset) {
1089 			pgroup_sid = (struct smb_sid *)((char *)parent_pntsd +
1090 					le32_to_cpu(parent_pntsd->gsidoffset));
1091 			pgroup_sid_size = 1 + 1 + 6 + (pgroup_sid->num_subauth * 4);
1092 		}
1093 
1094 		pntsd = kzalloc(sizeof(struct smb_ntsd) + powner_sid_size +
1095 				pgroup_sid_size + sizeof(struct smb_acl) +
1096 				nt_size, GFP_KERNEL);
1097 		if (!pntsd) {
1098 			rc = -ENOMEM;
1099 			goto free_aces_base;
1100 		}
1101 
1102 		pntsd->revision = cpu_to_le16(1);
1103 		pntsd->type = cpu_to_le16(SELF_RELATIVE | DACL_PRESENT);
1104 		if (le16_to_cpu(parent_pntsd->type) & DACL_AUTO_INHERITED)
1105 			pntsd->type |= cpu_to_le16(DACL_AUTO_INHERITED);
1106 		pntsd_size = sizeof(struct smb_ntsd);
1107 		pntsd->osidoffset = parent_pntsd->osidoffset;
1108 		pntsd->gsidoffset = parent_pntsd->gsidoffset;
1109 		pntsd->dacloffset = parent_pntsd->dacloffset;
1110 
1111 		if (pntsd->osidoffset) {
1112 			struct smb_sid *owner_sid = (struct smb_sid *)((char *)pntsd +
1113 					le32_to_cpu(pntsd->osidoffset));
1114 			memcpy(owner_sid, powner_sid, powner_sid_size);
1115 			pntsd_size += powner_sid_size;
1116 		}
1117 
1118 		if (pntsd->gsidoffset) {
1119 			struct smb_sid *group_sid = (struct smb_sid *)((char *)pntsd +
1120 					le32_to_cpu(pntsd->gsidoffset));
1121 			memcpy(group_sid, pgroup_sid, pgroup_sid_size);
1122 			pntsd_size += pgroup_sid_size;
1123 		}
1124 
1125 		if (pntsd->dacloffset) {
1126 			struct smb_ace *pace;
1127 
1128 			pdacl = (struct smb_acl *)((char *)pntsd + le32_to_cpu(pntsd->dacloffset));
1129 			pdacl->revision = cpu_to_le16(2);
1130 			pdacl->size = cpu_to_le16(sizeof(struct smb_acl) + nt_size);
1131 			pdacl->num_aces = cpu_to_le32(ace_cnt);
1132 			pace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl));
1133 			memcpy(pace, aces_base, nt_size);
1134 			pntsd_size += sizeof(struct smb_acl) + nt_size;
1135 		}
1136 
1137 		ksmbd_vfs_set_sd_xattr(conn, user_ns,
1138 				       path->dentry, pntsd, pntsd_size);
1139 		kfree(pntsd);
1140 	}
1141 
1142 free_aces_base:
1143 	kfree(aces_base);
1144 free_parent_pntsd:
1145 	kfree(parent_pntsd);
1146 	return rc;
1147 }
1148 
smb_inherit_flags(int flags,bool is_dir)1149 bool smb_inherit_flags(int flags, bool is_dir)
1150 {
1151 	if (!is_dir)
1152 		return (flags & OBJECT_INHERIT_ACE) != 0;
1153 
1154 	if (flags & OBJECT_INHERIT_ACE && !(flags & NO_PROPAGATE_INHERIT_ACE))
1155 		return true;
1156 
1157 	if (flags & CONTAINER_INHERIT_ACE)
1158 		return true;
1159 	return false;
1160 }
1161 
smb_check_perm_dacl(struct ksmbd_conn * conn,struct path * path,__le32 * pdaccess,int uid)1162 int smb_check_perm_dacl(struct ksmbd_conn *conn, struct path *path,
1163 			__le32 *pdaccess, int uid)
1164 {
1165 	struct user_namespace *user_ns = mnt_user_ns(path->mnt);
1166 	struct smb_ntsd *pntsd = NULL;
1167 	struct smb_acl *pdacl;
1168 	struct posix_acl *posix_acls;
1169 	int rc = 0, acl_size;
1170 	struct smb_sid sid;
1171 	int granted = le32_to_cpu(*pdaccess & ~FILE_MAXIMAL_ACCESS_LE);
1172 	struct smb_ace *ace;
1173 	int i, found = 0;
1174 	unsigned int access_bits = 0;
1175 	struct smb_ace *others_ace = NULL;
1176 	struct posix_acl_entry *pa_entry;
1177 	unsigned int sid_type = SIDOWNER;
1178 	char *end_of_acl;
1179 
1180 	ksmbd_debug(SMB, "check permission using windows acl\n");
1181 	acl_size = ksmbd_vfs_get_sd_xattr(conn, user_ns,
1182 					  path->dentry, &pntsd);
1183 	if (acl_size <= 0 || !pntsd || !pntsd->dacloffset) {
1184 		kfree(pntsd);
1185 		return 0;
1186 	}
1187 
1188 	pdacl = (struct smb_acl *)((char *)pntsd + le32_to_cpu(pntsd->dacloffset));
1189 	end_of_acl = ((char *)pntsd) + acl_size;
1190 	if (end_of_acl <= (char *)pdacl) {
1191 		kfree(pntsd);
1192 		return 0;
1193 	}
1194 
1195 	if (end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size) ||
1196 	    le16_to_cpu(pdacl->size) < sizeof(struct smb_acl)) {
1197 		kfree(pntsd);
1198 		return 0;
1199 	}
1200 
1201 	if (!pdacl->num_aces) {
1202 		if (!(le16_to_cpu(pdacl->size) - sizeof(struct smb_acl)) &&
1203 		    *pdaccess & ~(FILE_READ_CONTROL_LE | FILE_WRITE_DAC_LE)) {
1204 			rc = -EACCES;
1205 			goto err_out;
1206 		}
1207 		kfree(pntsd);
1208 		return 0;
1209 	}
1210 
1211 	if (*pdaccess & FILE_MAXIMAL_ACCESS_LE) {
1212 		granted = READ_CONTROL | WRITE_DAC | FILE_READ_ATTRIBUTES |
1213 			DELETE;
1214 
1215 		ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl));
1216 		for (i = 0; i < le32_to_cpu(pdacl->num_aces); i++) {
1217 			granted |= le32_to_cpu(ace->access_req);
1218 			ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size));
1219 			if (end_of_acl < (char *)ace)
1220 				goto err_out;
1221 		}
1222 
1223 		if (!pdacl->num_aces)
1224 			granted = GENERIC_ALL_FLAGS;
1225 	}
1226 
1227 	if (!uid)
1228 		sid_type = SIDUNIX_USER;
1229 	id_to_sid(uid, sid_type, &sid);
1230 
1231 	ace = (struct smb_ace *)((char *)pdacl + sizeof(struct smb_acl));
1232 	for (i = 0; i < le32_to_cpu(pdacl->num_aces); i++) {
1233 		if (!compare_sids(&sid, &ace->sid) ||
1234 		    !compare_sids(&sid_unix_NFS_mode, &ace->sid)) {
1235 			found = 1;
1236 			break;
1237 		}
1238 		if (!compare_sids(&sid_everyone, &ace->sid))
1239 			others_ace = ace;
1240 
1241 		ace = (struct smb_ace *)((char *)ace + le16_to_cpu(ace->size));
1242 		if (end_of_acl < (char *)ace)
1243 			goto err_out;
1244 	}
1245 
1246 	if (*pdaccess & FILE_MAXIMAL_ACCESS_LE && found) {
1247 		granted = READ_CONTROL | WRITE_DAC | FILE_READ_ATTRIBUTES |
1248 			DELETE;
1249 
1250 		granted |= le32_to_cpu(ace->access_req);
1251 
1252 		if (!pdacl->num_aces)
1253 			granted = GENERIC_ALL_FLAGS;
1254 	}
1255 
1256 	if (IS_ENABLED(CONFIG_FS_POSIX_ACL)) {
1257 		posix_acls = get_acl(d_inode(path->dentry), ACL_TYPE_ACCESS);
1258 		if (posix_acls && !found) {
1259 			unsigned int id = -1;
1260 
1261 			pa_entry = posix_acls->a_entries;
1262 			for (i = 0; i < posix_acls->a_count; i++, pa_entry++) {
1263 				if (pa_entry->e_tag == ACL_USER)
1264 					id = posix_acl_uid_translate(user_ns, pa_entry);
1265 				else if (pa_entry->e_tag == ACL_GROUP)
1266 					id = posix_acl_gid_translate(user_ns, pa_entry);
1267 				else
1268 					continue;
1269 
1270 				if (id == uid) {
1271 					mode_to_access_flags(pa_entry->e_perm,
1272 							     0777,
1273 							     &access_bits);
1274 					if (!access_bits)
1275 						access_bits =
1276 							SET_MINIMUM_RIGHTS;
1277 					goto check_access_bits;
1278 				}
1279 			}
1280 		}
1281 		if (posix_acls)
1282 			posix_acl_release(posix_acls);
1283 	}
1284 
1285 	if (!found) {
1286 		if (others_ace) {
1287 			ace = others_ace;
1288 		} else {
1289 			ksmbd_debug(SMB, "Can't find corresponding sid\n");
1290 			rc = -EACCES;
1291 			goto err_out;
1292 		}
1293 	}
1294 
1295 	switch (ace->type) {
1296 	case ACCESS_ALLOWED_ACE_TYPE:
1297 		access_bits = le32_to_cpu(ace->access_req);
1298 		break;
1299 	case ACCESS_DENIED_ACE_TYPE:
1300 	case ACCESS_DENIED_CALLBACK_ACE_TYPE:
1301 		access_bits = le32_to_cpu(~ace->access_req);
1302 		break;
1303 	}
1304 
1305 check_access_bits:
1306 	if (granted &
1307 	    ~(access_bits | FILE_READ_ATTRIBUTES | READ_CONTROL | WRITE_DAC | DELETE)) {
1308 		ksmbd_debug(SMB, "Access denied with winACL, granted : %x, access_req : %x\n",
1309 			    granted, le32_to_cpu(ace->access_req));
1310 		rc = -EACCES;
1311 		goto err_out;
1312 	}
1313 
1314 	*pdaccess = cpu_to_le32(granted);
1315 err_out:
1316 	kfree(pntsd);
1317 	return rc;
1318 }
1319 
set_info_sec(struct ksmbd_conn * conn,struct ksmbd_tree_connect * tcon,struct path * path,struct smb_ntsd * pntsd,int ntsd_len,bool type_check)1320 int set_info_sec(struct ksmbd_conn *conn, struct ksmbd_tree_connect *tcon,
1321 		 struct path *path, struct smb_ntsd *pntsd, int ntsd_len,
1322 		 bool type_check)
1323 {
1324 	int rc;
1325 	struct smb_fattr fattr = {{0}};
1326 	struct inode *inode = d_inode(path->dentry);
1327 	struct user_namespace *user_ns = mnt_user_ns(path->mnt);
1328 	struct iattr newattrs;
1329 
1330 	fattr.cf_uid = INVALID_UID;
1331 	fattr.cf_gid = INVALID_GID;
1332 	fattr.cf_mode = inode->i_mode;
1333 
1334 	rc = parse_sec_desc(user_ns, pntsd, ntsd_len, &fattr);
1335 	if (rc)
1336 		goto out;
1337 
1338 	newattrs.ia_valid = ATTR_CTIME;
1339 	if (!uid_eq(fattr.cf_uid, INVALID_UID)) {
1340 		newattrs.ia_valid |= ATTR_UID;
1341 		newattrs.ia_uid = fattr.cf_uid;
1342 	}
1343 	if (!gid_eq(fattr.cf_gid, INVALID_GID)) {
1344 		newattrs.ia_valid |= ATTR_GID;
1345 		newattrs.ia_gid = fattr.cf_gid;
1346 	}
1347 	newattrs.ia_valid |= ATTR_MODE;
1348 	newattrs.ia_mode = (inode->i_mode & ~0777) | (fattr.cf_mode & 0777);
1349 
1350 	ksmbd_vfs_remove_acl_xattrs(user_ns, path->dentry);
1351 	/* Update posix acls */
1352 	if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && fattr.cf_dacls) {
1353 		rc = set_posix_acl(user_ns, inode,
1354 				   ACL_TYPE_ACCESS, fattr.cf_acls);
1355 		if (rc < 0)
1356 			ksmbd_debug(SMB,
1357 				    "Set posix acl(ACL_TYPE_ACCESS) failed, rc : %d\n",
1358 				    rc);
1359 		if (S_ISDIR(inode->i_mode) && fattr.cf_dacls) {
1360 			rc = set_posix_acl(user_ns, inode,
1361 					   ACL_TYPE_DEFAULT, fattr.cf_dacls);
1362 			if (rc)
1363 				ksmbd_debug(SMB,
1364 					    "Set posix acl(ACL_TYPE_DEFAULT) failed, rc : %d\n",
1365 					    rc);
1366 		}
1367 	}
1368 
1369 	inode_lock(inode);
1370 	rc = notify_change(user_ns, path->dentry, &newattrs, NULL);
1371 	inode_unlock(inode);
1372 	if (rc)
1373 		goto out;
1374 
1375 	/* Check it only calling from SD BUFFER context */
1376 	if (type_check && !(le16_to_cpu(pntsd->type) & DACL_PRESENT))
1377 		goto out;
1378 
1379 	if (test_share_config_flag(tcon->share_conf, KSMBD_SHARE_FLAG_ACL_XATTR)) {
1380 		/* Update WinACL in xattr */
1381 		ksmbd_vfs_remove_sd_xattrs(user_ns, path->dentry);
1382 		ksmbd_vfs_set_sd_xattr(conn, user_ns,
1383 				       path->dentry, pntsd, ntsd_len);
1384 	}
1385 
1386 out:
1387 	posix_acl_release(fattr.cf_acls);
1388 	posix_acl_release(fattr.cf_dacls);
1389 	mark_inode_dirty(inode);
1390 	return rc;
1391 }
1392 
ksmbd_init_domain(u32 * sub_auth)1393 void ksmbd_init_domain(u32 *sub_auth)
1394 {
1395 	int i;
1396 
1397 	memcpy(&server_conf.domain_sid, &domain, sizeof(struct smb_sid));
1398 	for (i = 0; i < 3; ++i)
1399 		server_conf.domain_sid.sub_auth[i + 1] = cpu_to_le32(sub_auth[i]);
1400 }
1401