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e2f34481 NJ |
1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* | |
3 | * Copyright (C) 2016 Namjae Jeon <linkinjeon@kernel.org> | |
4 | * Copyright (C) 2018 Samsung Electronics Co., Ltd. | |
5 | */ | |
6 | ||
7 | #include "glob.h" | |
8 | #include "nterr.h" | |
9 | #include "smb2pdu.h" | |
10 | #include "smb_common.h" | |
11 | #include "smbstatus.h" | |
12 | #include "mgmt/user_session.h" | |
13 | #include "connection.h" | |
14 | ||
15 | static int check_smb2_hdr(struct smb2_hdr *hdr) | |
16 | { | |
17 | /* | |
18 | * Make sure that this really is an SMB, that it is a response. | |
19 | */ | |
20 | if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR) | |
21 | return 1; | |
22 | return 0; | |
23 | } | |
24 | ||
25 | /* | |
26 | * The following table defines the expected "StructureSize" of SMB2 requests | |
27 | * in order by SMB2 command. This is similar to "wct" in SMB/CIFS requests. | |
28 | * | |
29 | * Note that commands are defined in smb2pdu.h in le16 but the array below is | |
30 | * indexed by command in host byte order | |
31 | */ | |
32 | static const __le16 smb2_req_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = { | |
33 | /* SMB2_NEGOTIATE */ cpu_to_le16(36), | |
34 | /* SMB2_SESSION_SETUP */ cpu_to_le16(25), | |
35 | /* SMB2_LOGOFF */ cpu_to_le16(4), | |
36 | /* SMB2_TREE_CONNECT */ cpu_to_le16(9), | |
37 | /* SMB2_TREE_DISCONNECT */ cpu_to_le16(4), | |
38 | /* SMB2_CREATE */ cpu_to_le16(57), | |
39 | /* SMB2_CLOSE */ cpu_to_le16(24), | |
40 | /* SMB2_FLUSH */ cpu_to_le16(24), | |
41 | /* SMB2_READ */ cpu_to_le16(49), | |
42 | /* SMB2_WRITE */ cpu_to_le16(49), | |
43 | /* SMB2_LOCK */ cpu_to_le16(48), | |
44 | /* SMB2_IOCTL */ cpu_to_le16(57), | |
45 | /* SMB2_CANCEL */ cpu_to_le16(4), | |
46 | /* SMB2_ECHO */ cpu_to_le16(4), | |
47 | /* SMB2_QUERY_DIRECTORY */ cpu_to_le16(33), | |
48 | /* SMB2_CHANGE_NOTIFY */ cpu_to_le16(32), | |
49 | /* SMB2_QUERY_INFO */ cpu_to_le16(41), | |
50 | /* SMB2_SET_INFO */ cpu_to_le16(33), | |
51 | /* use 44 for lease break */ | |
52 | /* SMB2_OPLOCK_BREAK */ cpu_to_le16(36) | |
53 | }; | |
54 | ||
55 | /* | |
56 | * The size of the variable area depends on the offset and length fields | |
57 | * located in different fields for various SMB2 requests. SMB2 requests | |
58 | * with no variable length info, show an offset of zero for the offset field. | |
59 | */ | |
60 | static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = { | |
61 | /* SMB2_NEGOTIATE */ true, | |
62 | /* SMB2_SESSION_SETUP */ true, | |
63 | /* SMB2_LOGOFF */ false, | |
64 | /* SMB2_TREE_CONNECT */ true, | |
65 | /* SMB2_TREE_DISCONNECT */ false, | |
66 | /* SMB2_CREATE */ true, | |
67 | /* SMB2_CLOSE */ false, | |
68 | /* SMB2_FLUSH */ false, | |
69 | /* SMB2_READ */ true, | |
70 | /* SMB2_WRITE */ true, | |
71 | /* SMB2_LOCK */ true, | |
72 | /* SMB2_IOCTL */ true, | |
73 | /* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */ | |
74 | /* SMB2_ECHO */ false, | |
75 | /* SMB2_QUERY_DIRECTORY */ true, | |
76 | /* SMB2_CHANGE_NOTIFY */ false, | |
77 | /* SMB2_QUERY_INFO */ true, | |
78 | /* SMB2_SET_INFO */ true, | |
79 | /* SMB2_OPLOCK_BREAK */ false | |
80 | }; | |
81 | ||
82 | /* | |
c2e99d47 NJ |
83 | * Set length of the data area and the offset to arguments. |
84 | * if they are invalid, return error. | |
e2f34481 | 85 | */ |
c2e99d47 NJ |
86 | static int smb2_get_data_area_len(unsigned int *off, unsigned int *len, |
87 | struct smb2_hdr *hdr) | |
e2f34481 | 88 | { |
c2e99d47 NJ |
89 | int ret = 0; |
90 | ||
e2f34481 NJ |
91 | *off = 0; |
92 | *len = 0; | |
93 | ||
94 | /* error reqeusts do not have data area */ | |
95 | if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED && | |
64b39f4a | 96 | (((struct smb2_err_rsp *)hdr)->StructureSize) == SMB2_ERROR_STRUCTURE_SIZE2_LE) |
c2e99d47 | 97 | return ret; |
e2f34481 NJ |
98 | |
99 | /* | |
100 | * Following commands have data areas so we have to get the location | |
101 | * of the data buffer offset and data buffer length for the particular | |
102 | * command. | |
103 | */ | |
104 | switch (hdr->Command) { | |
105 | case SMB2_SESSION_SETUP: | |
64b39f4a NJ |
106 | *off = le16_to_cpu(((struct smb2_sess_setup_req *)hdr)->SecurityBufferOffset); |
107 | *len = le16_to_cpu(((struct smb2_sess_setup_req *)hdr)->SecurityBufferLength); | |
e2f34481 NJ |
108 | break; |
109 | case SMB2_TREE_CONNECT: | |
64b39f4a NJ |
110 | *off = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathOffset); |
111 | *len = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathLength); | |
e2f34481 NJ |
112 | break; |
113 | case SMB2_CREATE: | |
114 | { | |
115 | if (((struct smb2_create_req *)hdr)->CreateContextsLength) { | |
116 | *off = le32_to_cpu(((struct smb2_create_req *) | |
117 | hdr)->CreateContextsOffset); | |
118 | *len = le32_to_cpu(((struct smb2_create_req *) | |
119 | hdr)->CreateContextsLength); | |
120 | break; | |
121 | } | |
122 | ||
64b39f4a NJ |
123 | *off = le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset); |
124 | *len = le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength); | |
e2f34481 NJ |
125 | break; |
126 | } | |
127 | case SMB2_QUERY_INFO: | |
64b39f4a NJ |
128 | *off = le16_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferOffset); |
129 | *len = le32_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferLength); | |
e2f34481 NJ |
130 | break; |
131 | case SMB2_SET_INFO: | |
64b39f4a NJ |
132 | *off = le16_to_cpu(((struct smb2_set_info_req *)hdr)->BufferOffset); |
133 | *len = le32_to_cpu(((struct smb2_set_info_req *)hdr)->BufferLength); | |
e2f34481 NJ |
134 | break; |
135 | case SMB2_READ: | |
64b39f4a NJ |
136 | *off = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoOffset); |
137 | *len = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoLength); | |
e2f34481 NJ |
138 | break; |
139 | case SMB2_WRITE: | |
140 | if (((struct smb2_write_req *)hdr)->DataOffset) { | |
64b39f4a NJ |
141 | *off = le16_to_cpu(((struct smb2_write_req *)hdr)->DataOffset); |
142 | *len = le32_to_cpu(((struct smb2_write_req *)hdr)->Length); | |
e2f34481 NJ |
143 | break; |
144 | } | |
145 | ||
64b39f4a NJ |
146 | *off = le16_to_cpu(((struct smb2_write_req *)hdr)->WriteChannelInfoOffset); |
147 | *len = le16_to_cpu(((struct smb2_write_req *)hdr)->WriteChannelInfoLength); | |
e2f34481 NJ |
148 | break; |
149 | case SMB2_QUERY_DIRECTORY: | |
64b39f4a NJ |
150 | *off = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameOffset); |
151 | *len = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameLength); | |
e2f34481 NJ |
152 | break; |
153 | case SMB2_LOCK: | |
154 | { | |
155 | int lock_count; | |
156 | ||
157 | /* | |
158 | * smb2_lock request size is 48 included single | |
159 | * smb2_lock_element structure size. | |
160 | */ | |
64b39f4a | 161 | lock_count = le16_to_cpu(((struct smb2_lock_req *)hdr)->LockCount) - 1; |
e2f34481 NJ |
162 | if (lock_count > 0) { |
163 | *off = __SMB2_HEADER_STRUCTURE_SIZE + 48; | |
164 | *len = sizeof(struct smb2_lock_element) * lock_count; | |
165 | } | |
166 | break; | |
167 | } | |
168 | case SMB2_IOCTL: | |
64b39f4a | 169 | *off = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputOffset); |
e2f34481 | 170 | *len = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputCount); |
e2f34481 NJ |
171 | break; |
172 | default: | |
173 | ksmbd_debug(SMB, "no length check for command\n"); | |
174 | break; | |
175 | } | |
176 | ||
e2f34481 | 177 | if (*off > 4096) { |
c2e99d47 NJ |
178 | ksmbd_debug(SMB, "offset %d too large\n", *off); |
179 | ret = -EINVAL; | |
180 | } else if ((u64)*off + *len > MAX_STREAM_PROT_LEN) { | |
181 | ksmbd_debug(SMB, "Request is larger than maximum stream protocol length(%u): %llu\n", | |
182 | MAX_STREAM_PROT_LEN, (u64)*off + *len); | |
183 | ret = -EINVAL; | |
e2f34481 NJ |
184 | } |
185 | ||
c2e99d47 | 186 | return ret; |
e2f34481 NJ |
187 | } |
188 | ||
189 | /* | |
190 | * Calculate the size of the SMB message based on the fixed header | |
191 | * portion, the number of word parameters and the data portion of the message. | |
192 | */ | |
c2e99d47 | 193 | static int smb2_calc_size(void *buf, unsigned int *len) |
e2f34481 NJ |
194 | { |
195 | struct smb2_pdu *pdu = (struct smb2_pdu *)buf; | |
196 | struct smb2_hdr *hdr = &pdu->hdr; | |
c2e99d47 NJ |
197 | unsigned int offset; /* the offset from the beginning of SMB to data area */ |
198 | unsigned int data_length; /* the length of the variable length data area */ | |
199 | int ret; | |
200 | ||
e2f34481 | 201 | /* Structure Size has already been checked to make sure it is 64 */ |
c2e99d47 | 202 | *len = le16_to_cpu(hdr->StructureSize); |
e2f34481 NJ |
203 | |
204 | /* | |
205 | * StructureSize2, ie length of fixed parameter area has already | |
206 | * been checked to make sure it is the correct length. | |
207 | */ | |
c2e99d47 NJ |
208 | *len += le16_to_cpu(pdu->StructureSize2); |
209 | /* | |
210 | * StructureSize2 of smb2_lock pdu is set to 48, indicating | |
211 | * the size of smb2 lock request with single smb2_lock_element | |
212 | * regardless of number of locks. Subtract single | |
213 | * smb2_lock_element for correct buffer size check. | |
214 | */ | |
215 | if (hdr->Command == SMB2_LOCK) | |
216 | *len -= sizeof(struct smb2_lock_element); | |
e2f34481 NJ |
217 | |
218 | if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false) | |
219 | goto calc_size_exit; | |
220 | ||
c2e99d47 NJ |
221 | ret = smb2_get_data_area_len(&offset, &data_length, hdr); |
222 | if (ret) | |
223 | return ret; | |
224 | ksmbd_debug(SMB, "SMB2 data length %u offset %u\n", data_length, | |
070fb21e | 225 | offset); |
e2f34481 NJ |
226 | |
227 | if (data_length > 0) { | |
228 | /* | |
229 | * Check to make sure that data area begins after fixed area, | |
230 | * Note that last byte of the fixed area is part of data area | |
231 | * for some commands, typically those with odd StructureSize, | |
232 | * so we must add one to the calculation. | |
233 | */ | |
c2e99d47 | 234 | if (offset + 1 < *len) { |
e2f34481 | 235 | ksmbd_debug(SMB, |
c2e99d47 NJ |
236 | "data area offset %d overlaps SMB2 header %u\n", |
237 | offset + 1, *len); | |
238 | return -EINVAL; | |
239 | } | |
240 | ||
241 | *len = offset + data_length; | |
e2f34481 | 242 | } |
c2e99d47 | 243 | |
e2f34481 | 244 | calc_size_exit: |
c2e99d47 NJ |
245 | ksmbd_debug(SMB, "SMB2 len %u\n", *len); |
246 | return 0; | |
e2f34481 NJ |
247 | } |
248 | ||
249 | static inline int smb2_query_info_req_len(struct smb2_query_info_req *h) | |
250 | { | |
251 | return le32_to_cpu(h->InputBufferLength) + | |
252 | le32_to_cpu(h->OutputBufferLength); | |
253 | } | |
254 | ||
255 | static inline int smb2_set_info_req_len(struct smb2_set_info_req *h) | |
256 | { | |
257 | return le32_to_cpu(h->BufferLength); | |
258 | } | |
259 | ||
260 | static inline int smb2_read_req_len(struct smb2_read_req *h) | |
261 | { | |
262 | return le32_to_cpu(h->Length); | |
263 | } | |
264 | ||
265 | static inline int smb2_write_req_len(struct smb2_write_req *h) | |
266 | { | |
267 | return le32_to_cpu(h->Length); | |
268 | } | |
269 | ||
270 | static inline int smb2_query_dir_req_len(struct smb2_query_directory_req *h) | |
271 | { | |
272 | return le32_to_cpu(h->OutputBufferLength); | |
273 | } | |
274 | ||
275 | static inline int smb2_ioctl_req_len(struct smb2_ioctl_req *h) | |
276 | { | |
277 | return le32_to_cpu(h->InputCount) + | |
278 | le32_to_cpu(h->OutputCount); | |
279 | } | |
280 | ||
281 | static inline int smb2_ioctl_resp_len(struct smb2_ioctl_req *h) | |
282 | { | |
283 | return le32_to_cpu(h->MaxInputResponse) + | |
284 | le32_to_cpu(h->MaxOutputResponse); | |
285 | } | |
286 | ||
bf8acc9e HL |
287 | static int smb2_validate_credit_charge(struct ksmbd_conn *conn, |
288 | struct smb2_hdr *hdr) | |
e2f34481 | 289 | { |
bf8acc9e HL |
290 | unsigned int req_len = 0, expect_resp_len = 0, calc_credit_num, max_len; |
291 | unsigned short credit_charge = le16_to_cpu(hdr->CreditCharge); | |
e2f34481 | 292 | void *__hdr = hdr; |
bf8acc9e | 293 | int ret; |
e2f34481 NJ |
294 | |
295 | switch (hdr->Command) { | |
296 | case SMB2_QUERY_INFO: | |
297 | req_len = smb2_query_info_req_len(__hdr); | |
298 | break; | |
299 | case SMB2_SET_INFO: | |
300 | req_len = smb2_set_info_req_len(__hdr); | |
301 | break; | |
302 | case SMB2_READ: | |
303 | req_len = smb2_read_req_len(__hdr); | |
304 | break; | |
305 | case SMB2_WRITE: | |
306 | req_len = smb2_write_req_len(__hdr); | |
307 | break; | |
308 | case SMB2_QUERY_DIRECTORY: | |
309 | req_len = smb2_query_dir_req_len(__hdr); | |
310 | break; | |
311 | case SMB2_IOCTL: | |
312 | req_len = smb2_ioctl_req_len(__hdr); | |
313 | expect_resp_len = smb2_ioctl_resp_len(__hdr); | |
314 | break; | |
bf8acc9e | 315 | case SMB2_CANCEL: |
e2f34481 | 316 | return 0; |
bf8acc9e HL |
317 | default: |
318 | req_len = 1; | |
319 | break; | |
e2f34481 NJ |
320 | } |
321 | ||
bf8acc9e HL |
322 | credit_charge = max_t(unsigned short, credit_charge, 1); |
323 | max_len = max_t(unsigned int, req_len, expect_resp_len); | |
e2f34481 | 324 | calc_credit_num = DIV_ROUND_UP(max_len, SMB2_MAX_BUFFER_SIZE); |
a5a25a11 MM |
325 | |
326 | if (credit_charge < calc_credit_num) { | |
bf8acc9e HL |
327 | ksmbd_debug(SMB, "Insufficient credit charge, given: %d, needed: %d\n", |
328 | credit_charge, calc_credit_num); | |
329 | return 1; | |
330 | } else if (credit_charge > conn->max_credits) { | |
331 | ksmbd_debug(SMB, "Too large credit charge: %d\n", credit_charge); | |
e2f34481 NJ |
332 | return 1; |
333 | } | |
334 | ||
bf8acc9e HL |
335 | spin_lock(&conn->credits_lock); |
336 | if (credit_charge <= conn->total_credits) { | |
337 | conn->total_credits -= credit_charge; | |
338 | ret = 0; | |
339 | } else { | |
340 | ksmbd_debug(SMB, "Insufficient credits granted, given: %u, granted: %u\n", | |
341 | credit_charge, conn->total_credits); | |
342 | ret = 1; | |
343 | } | |
344 | spin_unlock(&conn->credits_lock); | |
345 | return ret; | |
e2f34481 NJ |
346 | } |
347 | ||
348 | int ksmbd_smb2_check_message(struct ksmbd_work *work) | |
349 | { | |
e5066499 | 350 | struct smb2_pdu *pdu = work->request_buf; |
e2f34481 NJ |
351 | struct smb2_hdr *hdr = &pdu->hdr; |
352 | int command; | |
353 | __u32 clc_len; /* calculated length */ | |
354 | __u32 len = get_rfc1002_len(pdu); | |
355 | ||
356 | if (work->next_smb2_rcv_hdr_off) { | |
8a893315 | 357 | pdu = ksmbd_req_buf_next(work); |
e2f34481 NJ |
358 | hdr = &pdu->hdr; |
359 | } | |
360 | ||
64b39f4a | 361 | if (le32_to_cpu(hdr->NextCommand) > 0) { |
e2f34481 | 362 | len = le32_to_cpu(hdr->NextCommand); |
64b39f4a | 363 | } else if (work->next_smb2_rcv_hdr_off) { |
e2f34481 NJ |
364 | len -= work->next_smb2_rcv_hdr_off; |
365 | len = round_up(len, 8); | |
366 | } | |
367 | ||
368 | if (check_smb2_hdr(hdr)) | |
369 | return 1; | |
370 | ||
371 | if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) { | |
372 | ksmbd_debug(SMB, "Illegal structure size %u\n", | |
070fb21e | 373 | le16_to_cpu(hdr->StructureSize)); |
e2f34481 NJ |
374 | return 1; |
375 | } | |
376 | ||
377 | command = le16_to_cpu(hdr->Command); | |
378 | if (command >= NUMBER_OF_SMB2_COMMANDS) { | |
379 | ksmbd_debug(SMB, "Illegal SMB2 command %d\n", command); | |
380 | return 1; | |
381 | } | |
382 | ||
383 | if (smb2_req_struct_sizes[command] != pdu->StructureSize2) { | |
64b39f4a NJ |
384 | if (command != SMB2_OPLOCK_BREAK_HE && |
385 | (hdr->Status == 0 || pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) { | |
e2f34481 NJ |
386 | /* error packets have 9 byte structure size */ |
387 | ksmbd_debug(SMB, | |
070fb21e NJ |
388 | "Illegal request size %u for command %d\n", |
389 | le16_to_cpu(pdu->StructureSize2), command); | |
e2f34481 | 390 | return 1; |
64b39f4a NJ |
391 | } else if (command == SMB2_OPLOCK_BREAK_HE && |
392 | hdr->Status == 0 && | |
393 | le16_to_cpu(pdu->StructureSize2) != OP_BREAK_STRUCT_SIZE_20 && | |
394 | le16_to_cpu(pdu->StructureSize2) != OP_BREAK_STRUCT_SIZE_21) { | |
e2f34481 NJ |
395 | /* special case for SMB2.1 lease break message */ |
396 | ksmbd_debug(SMB, | |
070fb21e NJ |
397 | "Illegal request size %d for oplock break\n", |
398 | le16_to_cpu(pdu->StructureSize2)); | |
e2f34481 NJ |
399 | return 1; |
400 | } | |
401 | } | |
402 | ||
c2e99d47 NJ |
403 | if (smb2_calc_size(hdr, &clc_len)) |
404 | return 1; | |
405 | ||
e2f34481 | 406 | if (len != clc_len) { |
c2e99d47 | 407 | /* client can return one byte more due to implied bcc[0] */ |
e2f34481 | 408 | if (clc_len == len + 1) |
7a334887 | 409 | goto validate_credit; |
e2f34481 NJ |
410 | |
411 | /* | |
412 | * Some windows servers (win2016) will pad also the final | |
413 | * PDU in a compound to 8 bytes. | |
414 | */ | |
415 | if (ALIGN(clc_len, 8) == len) | |
7a334887 | 416 | goto validate_credit; |
e2f34481 NJ |
417 | |
418 | /* | |
419 | * windows client also pad up to 8 bytes when compounding. | |
420 | * If pad is longer than eight bytes, log the server behavior | |
421 | * (once), since may indicate a problem but allow it and | |
422 | * continue since the frame is parseable. | |
423 | */ | |
424 | if (clc_len < len) { | |
425 | ksmbd_debug(SMB, | |
070fb21e NJ |
426 | "cli req padded more than expected. Length %d not %d for cmd:%d mid:%llu\n", |
427 | len, clc_len, command, | |
428 | le64_to_cpu(hdr->MessageId)); | |
7a334887 | 429 | goto validate_credit; |
e2f34481 NJ |
430 | } |
431 | ||
e2f34481 | 432 | ksmbd_debug(SMB, |
070fb21e NJ |
433 | "cli req too short, len %d not %d. cmd:%d mid:%llu\n", |
434 | len, clc_len, command, | |
435 | le64_to_cpu(hdr->MessageId)); | |
e2f34481 NJ |
436 | |
437 | return 1; | |
438 | } | |
439 | ||
7a334887 RB |
440 | validate_credit: |
441 | if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) && | |
442 | smb2_validate_credit_charge(work->conn, hdr)) { | |
443 | work->conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER); | |
444 | return 1; | |
445 | } | |
446 | ||
67307023 | 447 | return 0; |
e2f34481 NJ |
448 | } |
449 | ||
450 | int smb2_negotiate_request(struct ksmbd_work *work) | |
451 | { | |
452 | return ksmbd_smb_negotiate_common(work, SMB2_NEGOTIATE_HE); | |
453 | } |