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