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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" | |
e2f34481 NJ |
9 | #include "smb_common.h" |
10 | #include "smbstatus.h" | |
11 | #include "mgmt/user_session.h" | |
12 | #include "connection.h" | |
13 | ||
14 | static int check_smb2_hdr(struct smb2_hdr *hdr) | |
15 | { | |
16 | /* | |
17 | * Make sure that this really is an SMB, that it is a response. | |
18 | */ | |
19 | if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR) | |
20 | return 1; | |
21 | return 0; | |
22 | } | |
23 | ||
24 | /* | |
25 | * The following table defines the expected "StructureSize" of SMB2 requests | |
26 | * in order by SMB2 command. This is similar to "wct" in SMB/CIFS requests. | |
27 | * | |
28 | * Note that commands are defined in smb2pdu.h in le16 but the array below is | |
29 | * indexed by command in host byte order | |
30 | */ | |
31 | static const __le16 smb2_req_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = { | |
32 | /* SMB2_NEGOTIATE */ cpu_to_le16(36), | |
33 | /* SMB2_SESSION_SETUP */ cpu_to_le16(25), | |
34 | /* SMB2_LOGOFF */ cpu_to_le16(4), | |
35 | /* SMB2_TREE_CONNECT */ cpu_to_le16(9), | |
36 | /* SMB2_TREE_DISCONNECT */ cpu_to_le16(4), | |
37 | /* SMB2_CREATE */ cpu_to_le16(57), | |
38 | /* SMB2_CLOSE */ cpu_to_le16(24), | |
39 | /* SMB2_FLUSH */ cpu_to_le16(24), | |
40 | /* SMB2_READ */ cpu_to_le16(49), | |
41 | /* SMB2_WRITE */ cpu_to_le16(49), | |
42 | /* SMB2_LOCK */ cpu_to_le16(48), | |
43 | /* SMB2_IOCTL */ cpu_to_le16(57), | |
44 | /* SMB2_CANCEL */ cpu_to_le16(4), | |
45 | /* SMB2_ECHO */ cpu_to_le16(4), | |
46 | /* SMB2_QUERY_DIRECTORY */ cpu_to_le16(33), | |
47 | /* SMB2_CHANGE_NOTIFY */ cpu_to_le16(32), | |
48 | /* SMB2_QUERY_INFO */ cpu_to_le16(41), | |
49 | /* SMB2_SET_INFO */ cpu_to_le16(33), | |
50 | /* use 44 for lease break */ | |
51 | /* SMB2_OPLOCK_BREAK */ cpu_to_le16(36) | |
52 | }; | |
53 | ||
54 | /* | |
55 | * The size of the variable area depends on the offset and length fields | |
56 | * located in different fields for various SMB2 requests. SMB2 requests | |
57 | * with no variable length info, show an offset of zero for the offset field. | |
58 | */ | |
59 | static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = { | |
60 | /* SMB2_NEGOTIATE */ true, | |
61 | /* SMB2_SESSION_SETUP */ true, | |
62 | /* SMB2_LOGOFF */ false, | |
63 | /* SMB2_TREE_CONNECT */ true, | |
64 | /* SMB2_TREE_DISCONNECT */ false, | |
65 | /* SMB2_CREATE */ true, | |
66 | /* SMB2_CLOSE */ false, | |
67 | /* SMB2_FLUSH */ false, | |
68 | /* SMB2_READ */ true, | |
69 | /* SMB2_WRITE */ true, | |
70 | /* SMB2_LOCK */ true, | |
71 | /* SMB2_IOCTL */ true, | |
72 | /* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */ | |
73 | /* SMB2_ECHO */ false, | |
74 | /* SMB2_QUERY_DIRECTORY */ true, | |
75 | /* SMB2_CHANGE_NOTIFY */ false, | |
76 | /* SMB2_QUERY_INFO */ true, | |
77 | /* SMB2_SET_INFO */ true, | |
78 | /* SMB2_OPLOCK_BREAK */ false | |
79 | }; | |
80 | ||
81 | /* | |
c2e99d47 NJ |
82 | * Set length of the data area and the offset to arguments. |
83 | * if they are invalid, return error. | |
e2f34481 | 84 | */ |
c2e99d47 NJ |
85 | static int smb2_get_data_area_len(unsigned int *off, unsigned int *len, |
86 | struct smb2_hdr *hdr) | |
e2f34481 | 87 | { |
c2e99d47 NJ |
88 | int ret = 0; |
89 | ||
e2f34481 NJ |
90 | *off = 0; |
91 | *len = 0; | |
92 | ||
e2f34481 NJ |
93 | /* |
94 | * Following commands have data areas so we have to get the location | |
95 | * of the data buffer offset and data buffer length for the particular | |
96 | * command. | |
97 | */ | |
98 | switch (hdr->Command) { | |
99 | case SMB2_SESSION_SETUP: | |
64b39f4a NJ |
100 | *off = le16_to_cpu(((struct smb2_sess_setup_req *)hdr)->SecurityBufferOffset); |
101 | *len = le16_to_cpu(((struct smb2_sess_setup_req *)hdr)->SecurityBufferLength); | |
e2f34481 NJ |
102 | break; |
103 | case SMB2_TREE_CONNECT: | |
64b39f4a NJ |
104 | *off = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathOffset); |
105 | *len = le16_to_cpu(((struct smb2_tree_connect_req *)hdr)->PathLength); | |
e2f34481 NJ |
106 | break; |
107 | case SMB2_CREATE: | |
108 | { | |
109 | if (((struct smb2_create_req *)hdr)->CreateContextsLength) { | |
110 | *off = le32_to_cpu(((struct smb2_create_req *) | |
111 | hdr)->CreateContextsOffset); | |
112 | *len = le32_to_cpu(((struct smb2_create_req *) | |
113 | hdr)->CreateContextsLength); | |
114 | break; | |
115 | } | |
116 | ||
64b39f4a NJ |
117 | *off = le16_to_cpu(((struct smb2_create_req *)hdr)->NameOffset); |
118 | *len = le16_to_cpu(((struct smb2_create_req *)hdr)->NameLength); | |
e2f34481 NJ |
119 | break; |
120 | } | |
121 | case SMB2_QUERY_INFO: | |
64b39f4a NJ |
122 | *off = le16_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferOffset); |
123 | *len = le32_to_cpu(((struct smb2_query_info_req *)hdr)->InputBufferLength); | |
e2f34481 NJ |
124 | break; |
125 | case SMB2_SET_INFO: | |
64b39f4a NJ |
126 | *off = le16_to_cpu(((struct smb2_set_info_req *)hdr)->BufferOffset); |
127 | *len = le32_to_cpu(((struct smb2_set_info_req *)hdr)->BufferLength); | |
e2f34481 NJ |
128 | break; |
129 | case SMB2_READ: | |
64b39f4a NJ |
130 | *off = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoOffset); |
131 | *len = le16_to_cpu(((struct smb2_read_req *)hdr)->ReadChannelInfoLength); | |
e2f34481 NJ |
132 | break; |
133 | case SMB2_WRITE: | |
ac60778b HL |
134 | if (((struct smb2_write_req *)hdr)->DataOffset || |
135 | ((struct smb2_write_req *)hdr)->Length) { | |
136 | *off = max_t(unsigned int, | |
137 | le16_to_cpu(((struct smb2_write_req *)hdr)->DataOffset), | |
138 | offsetof(struct smb2_write_req, Buffer)); | |
64b39f4a | 139 | *len = le32_to_cpu(((struct smb2_write_req *)hdr)->Length); |
e2f34481 NJ |
140 | break; |
141 | } | |
142 | ||
64b39f4a NJ |
143 | *off = le16_to_cpu(((struct smb2_write_req *)hdr)->WriteChannelInfoOffset); |
144 | *len = le16_to_cpu(((struct smb2_write_req *)hdr)->WriteChannelInfoLength); | |
e2f34481 NJ |
145 | break; |
146 | case SMB2_QUERY_DIRECTORY: | |
64b39f4a NJ |
147 | *off = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameOffset); |
148 | *len = le16_to_cpu(((struct smb2_query_directory_req *)hdr)->FileNameLength); | |
e2f34481 NJ |
149 | break; |
150 | case SMB2_LOCK: | |
151 | { | |
8f8c43b1 | 152 | unsigned short lock_count; |
e2f34481 | 153 | |
8f8c43b1 | 154 | lock_count = le16_to_cpu(((struct smb2_lock_req *)hdr)->LockCount); |
e2f34481 | 155 | if (lock_count > 0) { |
8f8c43b1 | 156 | *off = offsetof(struct smb2_lock_req, locks); |
e2f34481 NJ |
157 | *len = sizeof(struct smb2_lock_element) * lock_count; |
158 | } | |
159 | break; | |
160 | } | |
161 | case SMB2_IOCTL: | |
64b39f4a | 162 | *off = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputOffset); |
e2f34481 | 163 | *len = le32_to_cpu(((struct smb2_ioctl_req *)hdr)->InputCount); |
e2f34481 NJ |
164 | break; |
165 | default: | |
166 | ksmbd_debug(SMB, "no length check for command\n"); | |
167 | break; | |
168 | } | |
169 | ||
e2f34481 | 170 | if (*off > 4096) { |
c2e99d47 NJ |
171 | ksmbd_debug(SMB, "offset %d too large\n", *off); |
172 | ret = -EINVAL; | |
173 | } else if ((u64)*off + *len > MAX_STREAM_PROT_LEN) { | |
174 | ksmbd_debug(SMB, "Request is larger than maximum stream protocol length(%u): %llu\n", | |
175 | MAX_STREAM_PROT_LEN, (u64)*off + *len); | |
176 | ret = -EINVAL; | |
e2f34481 NJ |
177 | } |
178 | ||
c2e99d47 | 179 | return ret; |
e2f34481 NJ |
180 | } |
181 | ||
182 | /* | |
183 | * Calculate the size of the SMB message based on the fixed header | |
184 | * portion, the number of word parameters and the data portion of the message. | |
185 | */ | |
c2e99d47 | 186 | static int smb2_calc_size(void *buf, unsigned int *len) |
e2f34481 NJ |
187 | { |
188 | struct smb2_pdu *pdu = (struct smb2_pdu *)buf; | |
189 | struct smb2_hdr *hdr = &pdu->hdr; | |
c2e99d47 NJ |
190 | unsigned int offset; /* the offset from the beginning of SMB to data area */ |
191 | unsigned int data_length; /* the length of the variable length data area */ | |
192 | int ret; | |
193 | ||
e2f34481 | 194 | /* Structure Size has already been checked to make sure it is 64 */ |
c2e99d47 | 195 | *len = le16_to_cpu(hdr->StructureSize); |
e2f34481 NJ |
196 | |
197 | /* | |
198 | * StructureSize2, ie length of fixed parameter area has already | |
199 | * been checked to make sure it is the correct length. | |
200 | */ | |
c2e99d47 NJ |
201 | *len += le16_to_cpu(pdu->StructureSize2); |
202 | /* | |
203 | * StructureSize2 of smb2_lock pdu is set to 48, indicating | |
204 | * the size of smb2 lock request with single smb2_lock_element | |
205 | * regardless of number of locks. Subtract single | |
206 | * smb2_lock_element for correct buffer size check. | |
207 | */ | |
208 | if (hdr->Command == SMB2_LOCK) | |
209 | *len -= sizeof(struct smb2_lock_element); | |
e2f34481 NJ |
210 | |
211 | if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false) | |
212 | goto calc_size_exit; | |
213 | ||
c2e99d47 NJ |
214 | ret = smb2_get_data_area_len(&offset, &data_length, hdr); |
215 | if (ret) | |
216 | return ret; | |
217 | ksmbd_debug(SMB, "SMB2 data length %u offset %u\n", data_length, | |
070fb21e | 218 | offset); |
e2f34481 NJ |
219 | |
220 | if (data_length > 0) { | |
221 | /* | |
222 | * Check to make sure that data area begins after fixed area, | |
223 | * Note that last byte of the fixed area is part of data area | |
224 | * for some commands, typically those with odd StructureSize, | |
225 | * so we must add one to the calculation. | |
226 | */ | |
c2e99d47 | 227 | if (offset + 1 < *len) { |
e2f34481 | 228 | ksmbd_debug(SMB, |
c2e99d47 NJ |
229 | "data area offset %d overlaps SMB2 header %u\n", |
230 | offset + 1, *len); | |
231 | return -EINVAL; | |
232 | } | |
233 | ||
234 | *len = offset + data_length; | |
e2f34481 | 235 | } |
c2e99d47 | 236 | |
e2f34481 | 237 | calc_size_exit: |
c2e99d47 NJ |
238 | ksmbd_debug(SMB, "SMB2 len %u\n", *len); |
239 | return 0; | |
e2f34481 NJ |
240 | } |
241 | ||
242 | static inline int smb2_query_info_req_len(struct smb2_query_info_req *h) | |
243 | { | |
244 | return le32_to_cpu(h->InputBufferLength) + | |
245 | le32_to_cpu(h->OutputBufferLength); | |
246 | } | |
247 | ||
248 | static inline int smb2_set_info_req_len(struct smb2_set_info_req *h) | |
249 | { | |
250 | return le32_to_cpu(h->BufferLength); | |
251 | } | |
252 | ||
253 | static inline int smb2_read_req_len(struct smb2_read_req *h) | |
254 | { | |
255 | return le32_to_cpu(h->Length); | |
256 | } | |
257 | ||
258 | static inline int smb2_write_req_len(struct smb2_write_req *h) | |
259 | { | |
260 | return le32_to_cpu(h->Length); | |
261 | } | |
262 | ||
263 | static inline int smb2_query_dir_req_len(struct smb2_query_directory_req *h) | |
264 | { | |
265 | return le32_to_cpu(h->OutputBufferLength); | |
266 | } | |
267 | ||
268 | static inline int smb2_ioctl_req_len(struct smb2_ioctl_req *h) | |
269 | { | |
270 | return le32_to_cpu(h->InputCount) + | |
271 | le32_to_cpu(h->OutputCount); | |
272 | } | |
273 | ||
274 | static inline int smb2_ioctl_resp_len(struct smb2_ioctl_req *h) | |
275 | { | |
276 | return le32_to_cpu(h->MaxInputResponse) + | |
277 | le32_to_cpu(h->MaxOutputResponse); | |
278 | } | |
279 | ||
bf8acc9e HL |
280 | static int smb2_validate_credit_charge(struct ksmbd_conn *conn, |
281 | struct smb2_hdr *hdr) | |
e2f34481 | 282 | { |
bf8acc9e HL |
283 | unsigned int req_len = 0, expect_resp_len = 0, calc_credit_num, max_len; |
284 | unsigned short credit_charge = le16_to_cpu(hdr->CreditCharge); | |
e2f34481 | 285 | void *__hdr = hdr; |
914d7e57 | 286 | int ret = 0; |
e2f34481 NJ |
287 | |
288 | switch (hdr->Command) { | |
289 | case SMB2_QUERY_INFO: | |
290 | req_len = smb2_query_info_req_len(__hdr); | |
291 | break; | |
292 | case SMB2_SET_INFO: | |
293 | req_len = smb2_set_info_req_len(__hdr); | |
294 | break; | |
295 | case SMB2_READ: | |
296 | req_len = smb2_read_req_len(__hdr); | |
297 | break; | |
298 | case SMB2_WRITE: | |
299 | req_len = smb2_write_req_len(__hdr); | |
300 | break; | |
301 | case SMB2_QUERY_DIRECTORY: | |
302 | req_len = smb2_query_dir_req_len(__hdr); | |
303 | break; | |
304 | case SMB2_IOCTL: | |
305 | req_len = smb2_ioctl_req_len(__hdr); | |
306 | expect_resp_len = smb2_ioctl_resp_len(__hdr); | |
307 | break; | |
bf8acc9e | 308 | case SMB2_CANCEL: |
e2f34481 | 309 | return 0; |
bf8acc9e HL |
310 | default: |
311 | req_len = 1; | |
312 | break; | |
e2f34481 NJ |
313 | } |
314 | ||
bf8acc9e HL |
315 | credit_charge = max_t(unsigned short, credit_charge, 1); |
316 | max_len = max_t(unsigned int, req_len, expect_resp_len); | |
e2f34481 | 317 | calc_credit_num = DIV_ROUND_UP(max_len, SMB2_MAX_BUFFER_SIZE); |
a5a25a11 MM |
318 | |
319 | if (credit_charge < calc_credit_num) { | |
bf8acc9e HL |
320 | ksmbd_debug(SMB, "Insufficient credit charge, given: %d, needed: %d\n", |
321 | credit_charge, calc_credit_num); | |
322 | return 1; | |
004443b3 | 323 | } else if (credit_charge > conn->vals->max_credits) { |
bf8acc9e | 324 | ksmbd_debug(SMB, "Too large credit charge: %d\n", credit_charge); |
e2f34481 NJ |
325 | return 1; |
326 | } | |
327 | ||
bf8acc9e | 328 | spin_lock(&conn->credits_lock); |
914d7e57 | 329 | if (credit_charge > conn->total_credits) { |
bf8acc9e HL |
330 | ksmbd_debug(SMB, "Insufficient credits granted, given: %u, granted: %u\n", |
331 | credit_charge, conn->total_credits); | |
332 | ret = 1; | |
333 | } | |
b589f5db | 334 | |
376b9133 | 335 | if ((u64)conn->outstanding_credits + credit_charge > conn->total_credits) { |
b589f5db NJ |
336 | ksmbd_debug(SMB, "Limits exceeding the maximum allowable outstanding requests, given : %u, pending : %u\n", |
337 | credit_charge, conn->outstanding_credits); | |
338 | ret = 1; | |
339 | } else | |
340 | conn->outstanding_credits += credit_charge; | |
341 | ||
bf8acc9e | 342 | spin_unlock(&conn->credits_lock); |
b589f5db | 343 | |
bf8acc9e | 344 | return ret; |
e2f34481 NJ |
345 | } |
346 | ||
347 | int ksmbd_smb2_check_message(struct ksmbd_work *work) | |
348 | { | |
b83b2790 | 349 | struct smb2_pdu *pdu = ksmbd_req_buf_next(work); |
e2f34481 NJ |
350 | struct smb2_hdr *hdr = &pdu->hdr; |
351 | int command; | |
352 | __u32 clc_len; /* calculated length */ | |
cb451720 | 353 | __u32 len = get_rfc1002_len(work->request_buf); |
e2f34481 | 354 | |
b53ad810 | 355 | if (le32_to_cpu(hdr->NextCommand) > 0) |
e2f34481 | 356 | len = le32_to_cpu(hdr->NextCommand); |
b53ad810 | 357 | else if (work->next_smb2_rcv_hdr_off) |
e2f34481 | 358 | len -= work->next_smb2_rcv_hdr_off; |
e2f34481 NJ |
359 | |
360 | if (check_smb2_hdr(hdr)) | |
361 | return 1; | |
362 | ||
363 | if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) { | |
364 | ksmbd_debug(SMB, "Illegal structure size %u\n", | |
070fb21e | 365 | le16_to_cpu(hdr->StructureSize)); |
e2f34481 NJ |
366 | return 1; |
367 | } | |
368 | ||
369 | command = le16_to_cpu(hdr->Command); | |
370 | if (command >= NUMBER_OF_SMB2_COMMANDS) { | |
371 | ksmbd_debug(SMB, "Illegal SMB2 command %d\n", command); | |
372 | return 1; | |
373 | } | |
374 | ||
375 | if (smb2_req_struct_sizes[command] != pdu->StructureSize2) { | |
64b39f4a NJ |
376 | if (command != SMB2_OPLOCK_BREAK_HE && |
377 | (hdr->Status == 0 || pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) { | |
e2f34481 NJ |
378 | /* error packets have 9 byte structure size */ |
379 | ksmbd_debug(SMB, | |
070fb21e NJ |
380 | "Illegal request size %u for command %d\n", |
381 | le16_to_cpu(pdu->StructureSize2), command); | |
e2f34481 | 382 | return 1; |
64b39f4a NJ |
383 | } else if (command == SMB2_OPLOCK_BREAK_HE && |
384 | hdr->Status == 0 && | |
385 | le16_to_cpu(pdu->StructureSize2) != OP_BREAK_STRUCT_SIZE_20 && | |
386 | le16_to_cpu(pdu->StructureSize2) != OP_BREAK_STRUCT_SIZE_21) { | |
e2f34481 NJ |
387 | /* special case for SMB2.1 lease break message */ |
388 | ksmbd_debug(SMB, | |
070fb21e NJ |
389 | "Illegal request size %d for oplock break\n", |
390 | le16_to_cpu(pdu->StructureSize2)); | |
e2f34481 NJ |
391 | return 1; |
392 | } | |
393 | } | |
394 | ||
c2e99d47 NJ |
395 | if (smb2_calc_size(hdr, &clc_len)) |
396 | return 1; | |
397 | ||
e2f34481 | 398 | if (len != clc_len) { |
c2e99d47 | 399 | /* client can return one byte more due to implied bcc[0] */ |
e2f34481 | 400 | if (clc_len == len + 1) |
7a334887 | 401 | goto validate_credit; |
e2f34481 NJ |
402 | |
403 | /* | |
404 | * Some windows servers (win2016) will pad also the final | |
405 | * PDU in a compound to 8 bytes. | |
406 | */ | |
407 | if (ALIGN(clc_len, 8) == len) | |
7a334887 | 408 | goto validate_credit; |
e2f34481 NJ |
409 | |
410 | /* | |
fb533473 NJ |
411 | * SMB2 NEGOTIATE request will be validated when message |
412 | * handling proceeds. | |
e2f34481 | 413 | */ |
fb533473 NJ |
414 | if (command == SMB2_NEGOTIATE_HE) |
415 | goto validate_credit; | |
416 | ||
417 | /* | |
418 | * Allow a message that padded to 8byte boundary. | |
419 | */ | |
420 | if (clc_len < len && (len - clc_len) < 8) | |
7a334887 | 421 | goto validate_credit; |
e2f34481 | 422 | |
fb533473 | 423 | pr_err_ratelimited( |
070fb21e NJ |
424 | "cli req too short, len %d not %d. cmd:%d mid:%llu\n", |
425 | len, clc_len, command, | |
426 | le64_to_cpu(hdr->MessageId)); | |
e2f34481 NJ |
427 | |
428 | return 1; | |
429 | } | |
430 | ||
7a334887 RB |
431 | validate_credit: |
432 | if ((work->conn->vals->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU) && | |
433 | smb2_validate_credit_charge(work->conn, hdr)) { | |
434 | work->conn->ops->set_rsp_status(work, STATUS_INVALID_PARAMETER); | |
435 | return 1; | |
436 | } | |
437 | ||
67307023 | 438 | return 0; |
e2f34481 NJ |
439 | } |
440 | ||
441 | int smb2_negotiate_request(struct ksmbd_work *work) | |
442 | { | |
443 | return ksmbd_smb_negotiate_common(work, SMB2_NEGOTIATE_HE); | |
444 | } |