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1 // SPDX-License-Identifier: LGPL-2.1
2 /*
3  *
4  *   Copyright (C) International Business Machines  Corp., 2002,2011
5  *                 Etersoft, 2012
6  *   Author(s): Steve French (sfrench@us.ibm.com)
7  *              Pavel Shilovsky (pshilovsky@samba.org) 2012
8  *
9  */
10 #include <linux/ctype.h>
11 #include "smb2pdu.h"
12 #include "cifsglob.h"
13 #include "cifsproto.h"
14 #include "smb2proto.h"
15 #include "cifs_debug.h"
16 #include "cifs_unicode.h"
17 #include "smb2status.h"
18 #include "smb2glob.h"
19 #include "nterr.h"
20 
21 static int
check_smb2_hdr(struct smb2_sync_hdr * shdr,__u64 mid)22 check_smb2_hdr(struct smb2_sync_hdr *shdr, __u64 mid)
23 {
24 	__u64 wire_mid = le64_to_cpu(shdr->MessageId);
25 
26 	/*
27 	 * Make sure that this really is an SMB, that it is a response,
28 	 * and that the message ids match.
29 	 */
30 	if ((shdr->ProtocolId == SMB2_PROTO_NUMBER) &&
31 	    (mid == wire_mid)) {
32 		if (shdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
33 			return 0;
34 		else {
35 			/* only one valid case where server sends us request */
36 			if (shdr->Command == SMB2_OPLOCK_BREAK)
37 				return 0;
38 			else
39 				cifs_dbg(VFS, "Received Request not response\n");
40 		}
41 	} else { /* bad signature or mid */
42 		if (shdr->ProtocolId != SMB2_PROTO_NUMBER)
43 			cifs_dbg(VFS, "Bad protocol string signature header %x\n",
44 				 le32_to_cpu(shdr->ProtocolId));
45 		if (mid != wire_mid)
46 			cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
47 				 mid, wire_mid);
48 	}
49 	cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
50 	return 1;
51 }
52 
53 /*
54  *  The following table defines the expected "StructureSize" of SMB2 responses
55  *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS responses.
56  *
57  *  Note that commands are defined in smb2pdu.h in le16 but the array below is
58  *  indexed by command in host byte order
59  */
60 static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
61 	/* SMB2_NEGOTIATE */ cpu_to_le16(65),
62 	/* SMB2_SESSION_SETUP */ cpu_to_le16(9),
63 	/* SMB2_LOGOFF */ cpu_to_le16(4),
64 	/* SMB2_TREE_CONNECT */ cpu_to_le16(16),
65 	/* SMB2_TREE_DISCONNECT */ cpu_to_le16(4),
66 	/* SMB2_CREATE */ cpu_to_le16(89),
67 	/* SMB2_CLOSE */ cpu_to_le16(60),
68 	/* SMB2_FLUSH */ cpu_to_le16(4),
69 	/* SMB2_READ */ cpu_to_le16(17),
70 	/* SMB2_WRITE */ cpu_to_le16(17),
71 	/* SMB2_LOCK */ cpu_to_le16(4),
72 	/* SMB2_IOCTL */ cpu_to_le16(49),
73 	/* BB CHECK this ... not listed in documentation */
74 	/* SMB2_CANCEL */ cpu_to_le16(0),
75 	/* SMB2_ECHO */ cpu_to_le16(4),
76 	/* SMB2_QUERY_DIRECTORY */ cpu_to_le16(9),
77 	/* SMB2_CHANGE_NOTIFY */ cpu_to_le16(9),
78 	/* SMB2_QUERY_INFO */ cpu_to_le16(9),
79 	/* SMB2_SET_INFO */ cpu_to_le16(2),
80 	/* BB FIXME can also be 44 for lease break */
81 	/* SMB2_OPLOCK_BREAK */ cpu_to_le16(24)
82 };
83 
84 #define SMB311_NEGPROT_BASE_SIZE (sizeof(struct smb2_sync_hdr) + sizeof(struct smb2_negotiate_rsp))
85 
get_neg_ctxt_len(struct smb2_sync_hdr * hdr,__u32 len,__u32 non_ctxlen)86 static __u32 get_neg_ctxt_len(struct smb2_sync_hdr *hdr, __u32 len,
87 			      __u32 non_ctxlen)
88 {
89 	__u16 neg_count;
90 	__u32 nc_offset, size_of_pad_before_neg_ctxts;
91 	struct smb2_negotiate_rsp *pneg_rsp = (struct smb2_negotiate_rsp *)hdr;
92 
93 	/* Negotiate contexts are only valid for latest dialect SMB3.11 */
94 	neg_count = le16_to_cpu(pneg_rsp->NegotiateContextCount);
95 	if ((neg_count == 0) ||
96 	   (pneg_rsp->DialectRevision != cpu_to_le16(SMB311_PROT_ID)))
97 		return 0;
98 
99 	/*
100 	 * if SPNEGO blob present (ie the RFC2478 GSS info which indicates
101 	 * which security mechanisms the server supports) make sure that
102 	 * the negotiate contexts start after it
103 	 */
104 	nc_offset = le32_to_cpu(pneg_rsp->NegotiateContextOffset);
105 	/*
106 	 * non_ctxlen is at least shdr->StructureSize + pdu->StructureSize2
107 	 * and the latter is 1 byte bigger than the fix-sized area of the
108 	 * NEGOTIATE response
109 	 */
110 	if (nc_offset + 1 < non_ctxlen) {
111 		pr_warn_once("Invalid negotiate context offset %d\n", nc_offset);
112 		return 0;
113 	} else if (nc_offset + 1 == non_ctxlen) {
114 		cifs_dbg(FYI, "no SPNEGO security blob in negprot rsp\n");
115 		size_of_pad_before_neg_ctxts = 0;
116 	} else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE + 1)
117 		/* has padding, but no SPNEGO blob */
118 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen + 1;
119 	else
120 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen;
121 
122 	/* Verify that at least minimal negotiate contexts fit within frame */
123 	if (len < nc_offset + (neg_count * sizeof(struct smb2_neg_context))) {
124 		pr_warn_once("negotiate context goes beyond end\n");
125 		return 0;
126 	}
127 
128 	cifs_dbg(FYI, "length of negcontexts %d pad %d\n",
129 		len - nc_offset, size_of_pad_before_neg_ctxts);
130 
131 	/* length of negcontexts including pad from end of sec blob to them */
132 	return (len - nc_offset) + size_of_pad_before_neg_ctxts;
133 }
134 
135 int
smb2_check_message(char * buf,unsigned int len,struct TCP_Server_Info * srvr)136 smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *srvr)
137 {
138 	struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buf;
139 	struct smb2_sync_pdu *pdu = (struct smb2_sync_pdu *)shdr;
140 	__u64 mid;
141 	__u32 clc_len;  /* calculated length */
142 	int command;
143 	int pdu_size = sizeof(struct smb2_sync_pdu);
144 	int hdr_size = sizeof(struct smb2_sync_hdr);
145 
146 	/*
147 	 * Add function to do table lookup of StructureSize by command
148 	 * ie Validate the wct via smb2_struct_sizes table above
149 	 */
150 	if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
151 		struct smb2_transform_hdr *thdr =
152 			(struct smb2_transform_hdr *)buf;
153 		struct cifs_ses *ses = NULL;
154 
155 		/* decrypt frame now that it is completely read in */
156 		spin_lock(&cifs_tcp_ses_lock);
157 		list_for_each_entry(ses, &srvr->smb_ses_list, smb_ses_list) {
158 			if (ses->Suid == thdr->SessionId)
159 				break;
160 		}
161 		spin_unlock(&cifs_tcp_ses_lock);
162 		if (list_entry_is_head(ses, &srvr->smb_ses_list,
163 				       smb_ses_list)) {
164 			cifs_dbg(VFS, "no decryption - session id not found\n");
165 			return 1;
166 		}
167 	}
168 
169 	mid = le64_to_cpu(shdr->MessageId);
170 	if (len < pdu_size) {
171 		if ((len >= hdr_size)
172 		    && (shdr->Status != 0)) {
173 			pdu->StructureSize2 = 0;
174 			/*
175 			 * As with SMB/CIFS, on some error cases servers may
176 			 * not return wct properly
177 			 */
178 			return 0;
179 		} else {
180 			cifs_dbg(VFS, "Length less than SMB header size\n");
181 		}
182 		return 1;
183 	}
184 	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE) {
185 		cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
186 			 mid);
187 		return 1;
188 	}
189 
190 	if (check_smb2_hdr(shdr, mid))
191 		return 1;
192 
193 	if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
194 		cifs_dbg(VFS, "Invalid structure size %u\n",
195 			 le16_to_cpu(shdr->StructureSize));
196 		return 1;
197 	}
198 
199 	command = le16_to_cpu(shdr->Command);
200 	if (command >= NUMBER_OF_SMB2_COMMANDS) {
201 		cifs_dbg(VFS, "Invalid SMB2 command %d\n", command);
202 		return 1;
203 	}
204 
205 	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
206 		if (command != SMB2_OPLOCK_BREAK_HE && (shdr->Status == 0 ||
207 		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2)) {
208 			/* error packets have 9 byte structure size */
209 			cifs_dbg(VFS, "Invalid response size %u for command %d\n",
210 				 le16_to_cpu(pdu->StructureSize2), command);
211 			return 1;
212 		} else if (command == SMB2_OPLOCK_BREAK_HE
213 			   && (shdr->Status == 0)
214 			   && (le16_to_cpu(pdu->StructureSize2) != 44)
215 			   && (le16_to_cpu(pdu->StructureSize2) != 36)) {
216 			/* special case for SMB2.1 lease break message */
217 			cifs_dbg(VFS, "Invalid response size %d for oplock break\n",
218 				 le16_to_cpu(pdu->StructureSize2));
219 			return 1;
220 		}
221 	}
222 
223 	clc_len = smb2_calc_size(buf, srvr);
224 
225 	if (shdr->Command == SMB2_NEGOTIATE)
226 		clc_len += get_neg_ctxt_len(shdr, len, clc_len);
227 
228 	if (len != clc_len) {
229 		cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n",
230 			 clc_len, len, mid);
231 		/* create failed on symlink */
232 		if (command == SMB2_CREATE_HE &&
233 		    shdr->Status == STATUS_STOPPED_ON_SYMLINK)
234 			return 0;
235 		/* Windows 7 server returns 24 bytes more */
236 		if (clc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE)
237 			return 0;
238 		/* server can return one byte more due to implied bcc[0] */
239 		if (clc_len == len + 1)
240 			return 0;
241 
242 		/*
243 		 * Some windows servers (win2016) will pad also the final
244 		 * PDU in a compound to 8 bytes.
245 		 */
246 		if (((clc_len + 7) & ~7) == len)
247 			return 0;
248 
249 		/*
250 		 * MacOS server pads after SMB2.1 write response with 3 bytes
251 		 * of junk. Other servers match RFC1001 len to actual
252 		 * SMB2/SMB3 frame length (header + smb2 response specific data)
253 		 * Some windows servers also pad up to 8 bytes when compounding.
254 		 */
255 		if (clc_len < len)
256 			return 0;
257 
258 		pr_warn_once(
259 			"srv rsp too short, len %d not %d. cmd:%d mid:%llu\n",
260 			len, clc_len, command, mid);
261 
262 		return 1;
263 	}
264 	return 0;
265 }
266 
267 /*
268  * The size of the variable area depends on the offset and length fields
269  * located in different fields for various SMB2 responses. SMB2 responses
270  * with no variable length info, show an offset of zero for the offset field.
271  */
272 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
273 	/* SMB2_NEGOTIATE */ true,
274 	/* SMB2_SESSION_SETUP */ true,
275 	/* SMB2_LOGOFF */ false,
276 	/* SMB2_TREE_CONNECT */	false,
277 	/* SMB2_TREE_DISCONNECT */ false,
278 	/* SMB2_CREATE */ true,
279 	/* SMB2_CLOSE */ false,
280 	/* SMB2_FLUSH */ false,
281 	/* SMB2_READ */	true,
282 	/* SMB2_WRITE */ false,
283 	/* SMB2_LOCK */	false,
284 	/* SMB2_IOCTL */ true,
285 	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
286 	/* SMB2_ECHO */ false,
287 	/* SMB2_QUERY_DIRECTORY */ true,
288 	/* SMB2_CHANGE_NOTIFY */ true,
289 	/* SMB2_QUERY_INFO */ true,
290 	/* SMB2_SET_INFO */ false,
291 	/* SMB2_OPLOCK_BREAK */ false
292 };
293 
294 /*
295  * Returns the pointer to the beginning of the data area. Length of the data
296  * area and the offset to it (from the beginning of the smb are also returned.
297  */
298 char *
smb2_get_data_area_len(int * off,int * len,struct smb2_sync_hdr * shdr)299 smb2_get_data_area_len(int *off, int *len, struct smb2_sync_hdr *shdr)
300 {
301 	const int max_off = 4096;
302 	const int max_len = 128 * 1024;
303 
304 	*off = 0;
305 	*len = 0;
306 
307 	/* error responses do not have data area */
308 	if (shdr->Status && shdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
309 	    (((struct smb2_err_rsp *)shdr)->StructureSize) ==
310 						SMB2_ERROR_STRUCTURE_SIZE2)
311 		return NULL;
312 
313 	/*
314 	 * Following commands have data areas so we have to get the location
315 	 * of the data buffer offset and data buffer length for the particular
316 	 * command.
317 	 */
318 	switch (shdr->Command) {
319 	case SMB2_NEGOTIATE:
320 		*off = le16_to_cpu(
321 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferOffset);
322 		*len = le16_to_cpu(
323 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferLength);
324 		break;
325 	case SMB2_SESSION_SETUP:
326 		*off = le16_to_cpu(
327 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferOffset);
328 		*len = le16_to_cpu(
329 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferLength);
330 		break;
331 	case SMB2_CREATE:
332 		*off = le32_to_cpu(
333 		    ((struct smb2_create_rsp *)shdr)->CreateContextsOffset);
334 		*len = le32_to_cpu(
335 		    ((struct smb2_create_rsp *)shdr)->CreateContextsLength);
336 		break;
337 	case SMB2_QUERY_INFO:
338 		*off = le16_to_cpu(
339 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferOffset);
340 		*len = le32_to_cpu(
341 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferLength);
342 		break;
343 	case SMB2_READ:
344 		/* TODO: is this a bug ? */
345 		*off = ((struct smb2_read_rsp *)shdr)->DataOffset;
346 		*len = le32_to_cpu(((struct smb2_read_rsp *)shdr)->DataLength);
347 		break;
348 	case SMB2_QUERY_DIRECTORY:
349 		*off = le16_to_cpu(
350 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferOffset);
351 		*len = le32_to_cpu(
352 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferLength);
353 		break;
354 	case SMB2_IOCTL:
355 		*off = le32_to_cpu(
356 		  ((struct smb2_ioctl_rsp *)shdr)->OutputOffset);
357 		*len = le32_to_cpu(
358 		  ((struct smb2_ioctl_rsp *)shdr)->OutputCount);
359 		break;
360 	case SMB2_CHANGE_NOTIFY:
361 		*off = le16_to_cpu(
362 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferOffset);
363 		*len = le32_to_cpu(
364 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferLength);
365 		break;
366 	default:
367 		cifs_dbg(VFS, "no length check for command %d\n", le16_to_cpu(shdr->Command));
368 		break;
369 	}
370 
371 	/*
372 	 * Invalid length or offset probably means data area is invalid, but
373 	 * we have little choice but to ignore the data area in this case.
374 	 */
375 	if (unlikely(*off < 0 || *off > max_off ||
376 		     *len < 0 || *len > max_len)) {
377 		cifs_dbg(VFS, "%s: invalid data area (off=%d len=%d)\n",
378 			 __func__, *off, *len);
379 		*off = 0;
380 		*len = 0;
381 	} else if (*off == 0) {
382 		*len = 0;
383 	}
384 
385 	/* return pointer to beginning of data area, ie offset from SMB start */
386 	if (*off > 0 && *len > 0)
387 		return (char *)shdr + *off;
388 	return NULL;
389 }
390 
391 /*
392  * Calculate the size of the SMB message based on the fixed header
393  * portion, the number of word parameters and the data portion of the message.
394  */
395 unsigned int
smb2_calc_size(void * buf,struct TCP_Server_Info * srvr)396 smb2_calc_size(void *buf, struct TCP_Server_Info *srvr)
397 {
398 	struct smb2_sync_pdu *pdu = (struct smb2_sync_pdu *)buf;
399 	struct smb2_sync_hdr *shdr = &pdu->sync_hdr;
400 	int offset; /* the offset from the beginning of SMB to data area */
401 	int data_length; /* the length of the variable length data area */
402 	/* Structure Size has already been checked to make sure it is 64 */
403 	int len = le16_to_cpu(shdr->StructureSize);
404 
405 	/*
406 	 * StructureSize2, ie length of fixed parameter area has already
407 	 * been checked to make sure it is the correct length.
408 	 */
409 	len += le16_to_cpu(pdu->StructureSize2);
410 
411 	if (has_smb2_data_area[le16_to_cpu(shdr->Command)] == false)
412 		goto calc_size_exit;
413 
414 	smb2_get_data_area_len(&offset, &data_length, shdr);
415 	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
416 
417 	if (data_length > 0) {
418 		/*
419 		 * Check to make sure that data area begins after fixed area,
420 		 * Note that last byte of the fixed area is part of data area
421 		 * for some commands, typically those with odd StructureSize,
422 		 * so we must add one to the calculation.
423 		 */
424 		if (offset + 1 < len) {
425 			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
426 				 offset + 1, len);
427 			data_length = 0;
428 		} else {
429 			len = offset + data_length;
430 		}
431 	}
432 calc_size_exit:
433 	cifs_dbg(FYI, "SMB2 len %d\n", len);
434 	return len;
435 }
436 
437 /* Note: caller must free return buffer */
438 __le16 *
cifs_convert_path_to_utf16(const char * from,struct cifs_sb_info * cifs_sb)439 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
440 {
441 	int len;
442 	const char *start_of_path;
443 	__le16 *to;
444 	int map_type;
445 
446 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
447 		map_type = SFM_MAP_UNI_RSVD;
448 	else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
449 		map_type = SFU_MAP_UNI_RSVD;
450 	else
451 		map_type = NO_MAP_UNI_RSVD;
452 
453 	/* Windows doesn't allow paths beginning with \ */
454 	if (from[0] == '\\')
455 		start_of_path = from + 1;
456 
457 	/* SMB311 POSIX extensions paths do not include leading slash */
458 	else if (cifs_sb_master_tlink(cifs_sb) &&
459 		 cifs_sb_master_tcon(cifs_sb)->posix_extensions &&
460 		 (from[0] == '/')) {
461 		start_of_path = from + 1;
462 	} else
463 		start_of_path = from;
464 
465 	to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
466 				   cifs_sb->local_nls, map_type);
467 	return to;
468 }
469 
470 __le32
smb2_get_lease_state(struct cifsInodeInfo * cinode)471 smb2_get_lease_state(struct cifsInodeInfo *cinode)
472 {
473 	__le32 lease = 0;
474 
475 	if (CIFS_CACHE_WRITE(cinode))
476 		lease |= SMB2_LEASE_WRITE_CACHING;
477 	if (CIFS_CACHE_HANDLE(cinode))
478 		lease |= SMB2_LEASE_HANDLE_CACHING;
479 	if (CIFS_CACHE_READ(cinode))
480 		lease |= SMB2_LEASE_READ_CACHING;
481 	return lease;
482 }
483 
484 struct smb2_lease_break_work {
485 	struct work_struct lease_break;
486 	struct tcon_link *tlink;
487 	__u8 lease_key[16];
488 	__le32 lease_state;
489 };
490 
491 static void
cifs_ses_oplock_break(struct work_struct * work)492 cifs_ses_oplock_break(struct work_struct *work)
493 {
494 	struct smb2_lease_break_work *lw = container_of(work,
495 				struct smb2_lease_break_work, lease_break);
496 	int rc = 0;
497 
498 	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
499 			      lw->lease_state);
500 
501 	cifs_dbg(FYI, "Lease release rc %d\n", rc);
502 	cifs_put_tlink(lw->tlink);
503 	kfree(lw);
504 }
505 
506 static void
smb2_queue_pending_open_break(struct tcon_link * tlink,__u8 * lease_key,__le32 new_lease_state)507 smb2_queue_pending_open_break(struct tcon_link *tlink, __u8 *lease_key,
508 			      __le32 new_lease_state)
509 {
510 	struct smb2_lease_break_work *lw;
511 
512 	lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
513 	if (!lw) {
514 		cifs_put_tlink(tlink);
515 		return;
516 	}
517 
518 	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
519 	lw->tlink = tlink;
520 	lw->lease_state = new_lease_state;
521 	memcpy(lw->lease_key, lease_key, SMB2_LEASE_KEY_SIZE);
522 	queue_work(cifsiod_wq, &lw->lease_break);
523 }
524 
525 static bool
smb2_tcon_has_lease(struct cifs_tcon * tcon,struct smb2_lease_break * rsp)526 smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp)
527 {
528 	__u8 lease_state;
529 	struct cifsFileInfo *cfile;
530 	struct cifsInodeInfo *cinode;
531 	int ack_req = le32_to_cpu(rsp->Flags &
532 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
533 
534 	lease_state = le32_to_cpu(rsp->NewLeaseState);
535 
536 	list_for_each_entry(cfile, &tcon->openFileList, tlist) {
537 		cinode = CIFS_I(d_inode(cfile->dentry));
538 
539 		if (memcmp(cinode->lease_key, rsp->LeaseKey,
540 							SMB2_LEASE_KEY_SIZE))
541 			continue;
542 
543 		cifs_dbg(FYI, "found in the open list\n");
544 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
545 			 lease_state);
546 
547 		if (ack_req)
548 			cfile->oplock_break_cancelled = false;
549 		else
550 			cfile->oplock_break_cancelled = true;
551 
552 		set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
553 
554 		cfile->oplock_epoch = le16_to_cpu(rsp->Epoch);
555 		cfile->oplock_level = lease_state;
556 
557 		cifs_queue_oplock_break(cfile);
558 		return true;
559 	}
560 
561 	return false;
562 }
563 
564 static struct cifs_pending_open *
smb2_tcon_find_pending_open_lease(struct cifs_tcon * tcon,struct smb2_lease_break * rsp)565 smb2_tcon_find_pending_open_lease(struct cifs_tcon *tcon,
566 				  struct smb2_lease_break *rsp)
567 {
568 	__u8 lease_state = le32_to_cpu(rsp->NewLeaseState);
569 	int ack_req = le32_to_cpu(rsp->Flags &
570 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
571 	struct cifs_pending_open *open;
572 	struct cifs_pending_open *found = NULL;
573 
574 	list_for_each_entry(open, &tcon->pending_opens, olist) {
575 		if (memcmp(open->lease_key, rsp->LeaseKey,
576 			   SMB2_LEASE_KEY_SIZE))
577 			continue;
578 
579 		if (!found && ack_req) {
580 			found = open;
581 		}
582 
583 		cifs_dbg(FYI, "found in the pending open list\n");
584 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
585 			 lease_state);
586 
587 		open->oplock = lease_state;
588 	}
589 
590 	return found;
591 }
592 
593 static bool
smb2_is_valid_lease_break(char * buffer)594 smb2_is_valid_lease_break(char *buffer)
595 {
596 	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
597 	struct TCP_Server_Info *server;
598 	struct cifs_ses *ses;
599 	struct cifs_tcon *tcon;
600 	struct cifs_pending_open *open;
601 
602 	cifs_dbg(FYI, "Checking for lease break\n");
603 
604 	/* look up tcon based on tid & uid */
605 	spin_lock(&cifs_tcp_ses_lock);
606 	list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
607 		list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
608 			list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
609 				spin_lock(&tcon->open_file_lock);
610 				cifs_stats_inc(
611 				    &tcon->stats.cifs_stats.num_oplock_brks);
612 				if (smb2_tcon_has_lease(tcon, rsp)) {
613 					spin_unlock(&tcon->open_file_lock);
614 					spin_unlock(&cifs_tcp_ses_lock);
615 					return true;
616 				}
617 				open = smb2_tcon_find_pending_open_lease(tcon,
618 									 rsp);
619 				if (open) {
620 					__u8 lease_key[SMB2_LEASE_KEY_SIZE];
621 					struct tcon_link *tlink;
622 
623 					tlink = cifs_get_tlink(open->tlink);
624 					memcpy(lease_key, open->lease_key,
625 					       SMB2_LEASE_KEY_SIZE);
626 					spin_unlock(&tcon->open_file_lock);
627 					spin_unlock(&cifs_tcp_ses_lock);
628 					smb2_queue_pending_open_break(tlink,
629 								      lease_key,
630 								      rsp->NewLeaseState);
631 					return true;
632 				}
633 				spin_unlock(&tcon->open_file_lock);
634 
635 				if (tcon->crfid.is_valid &&
636 				    !memcmp(rsp->LeaseKey,
637 					    tcon->crfid.fid->lease_key,
638 					    SMB2_LEASE_KEY_SIZE)) {
639 					tcon->crfid.time = 0;
640 					INIT_WORK(&tcon->crfid.lease_break,
641 						  smb2_cached_lease_break);
642 					queue_work(cifsiod_wq,
643 						   &tcon->crfid.lease_break);
644 					spin_unlock(&cifs_tcp_ses_lock);
645 					return true;
646 				}
647 			}
648 		}
649 	}
650 	spin_unlock(&cifs_tcp_ses_lock);
651 	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
652 	return false;
653 }
654 
655 bool
smb2_is_valid_oplock_break(char * buffer,struct TCP_Server_Info * server)656 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
657 {
658 	struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
659 	struct cifs_ses *ses;
660 	struct cifs_tcon *tcon;
661 	struct cifsInodeInfo *cinode;
662 	struct cifsFileInfo *cfile;
663 
664 	cifs_dbg(FYI, "Checking for oplock break\n");
665 
666 	if (rsp->sync_hdr.Command != SMB2_OPLOCK_BREAK)
667 		return false;
668 
669 	if (rsp->StructureSize !=
670 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
671 		if (le16_to_cpu(rsp->StructureSize) == 44)
672 			return smb2_is_valid_lease_break(buffer);
673 		else
674 			return false;
675 	}
676 
677 	cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
678 
679 	/* look up tcon based on tid & uid */
680 	spin_lock(&cifs_tcp_ses_lock);
681 	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
682 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
683 
684 			spin_lock(&tcon->open_file_lock);
685 			list_for_each_entry(cfile, &tcon->openFileList, tlist) {
686 				if (rsp->PersistentFid !=
687 				    cfile->fid.persistent_fid ||
688 				    rsp->VolatileFid !=
689 				    cfile->fid.volatile_fid)
690 					continue;
691 
692 				cifs_dbg(FYI, "file id match, oplock break\n");
693 				cifs_stats_inc(
694 				    &tcon->stats.cifs_stats.num_oplock_brks);
695 				cinode = CIFS_I(d_inode(cfile->dentry));
696 				spin_lock(&cfile->file_info_lock);
697 				if (!CIFS_CACHE_WRITE(cinode) &&
698 				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
699 					cfile->oplock_break_cancelled = true;
700 				else
701 					cfile->oplock_break_cancelled = false;
702 
703 				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
704 					&cinode->flags);
705 
706 				cfile->oplock_epoch = 0;
707 				cfile->oplock_level = rsp->OplockLevel;
708 
709 				spin_unlock(&cfile->file_info_lock);
710 
711 				cifs_queue_oplock_break(cfile);
712 
713 				spin_unlock(&tcon->open_file_lock);
714 				spin_unlock(&cifs_tcp_ses_lock);
715 				return true;
716 			}
717 			spin_unlock(&tcon->open_file_lock);
718 		}
719 	}
720 	spin_unlock(&cifs_tcp_ses_lock);
721 	cifs_dbg(FYI, "No file id matched, oplock break ignored\n");
722 	return true;
723 }
724 
725 void
smb2_cancelled_close_fid(struct work_struct * work)726 smb2_cancelled_close_fid(struct work_struct *work)
727 {
728 	struct close_cancelled_open *cancelled = container_of(work,
729 					struct close_cancelled_open, work);
730 	struct cifs_tcon *tcon = cancelled->tcon;
731 	int rc;
732 
733 	if (cancelled->mid)
734 		cifs_tcon_dbg(VFS, "Close unmatched open for MID:%llu\n",
735 			      cancelled->mid);
736 	else
737 		cifs_tcon_dbg(VFS, "Close interrupted close\n");
738 
739 	rc = SMB2_close(0, tcon, cancelled->fid.persistent_fid,
740 			cancelled->fid.volatile_fid);
741 	if (rc)
742 		cifs_tcon_dbg(VFS, "Close cancelled mid failed rc:%d\n", rc);
743 
744 	cifs_put_tcon(tcon);
745 	kfree(cancelled);
746 }
747 
748 /*
749  * Caller should already has an extra reference to @tcon
750  * This function is used to queue work to close a handle to prevent leaks
751  * on the server.
752  * We handle two cases. If an open was interrupted after we sent the
753  * SMB2_CREATE to the server but before we processed the reply, and second
754  * if a close was interrupted before we sent the SMB2_CLOSE to the server.
755  */
756 static int
__smb2_handle_cancelled_cmd(struct cifs_tcon * tcon,__u16 cmd,__u64 mid,__u64 persistent_fid,__u64 volatile_fid)757 __smb2_handle_cancelled_cmd(struct cifs_tcon *tcon, __u16 cmd, __u64 mid,
758 			    __u64 persistent_fid, __u64 volatile_fid)
759 {
760 	struct close_cancelled_open *cancelled;
761 
762 	cancelled = kzalloc(sizeof(*cancelled), GFP_ATOMIC);
763 	if (!cancelled)
764 		return -ENOMEM;
765 
766 	cancelled->fid.persistent_fid = persistent_fid;
767 	cancelled->fid.volatile_fid = volatile_fid;
768 	cancelled->tcon = tcon;
769 	cancelled->cmd = cmd;
770 	cancelled->mid = mid;
771 	INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
772 	WARN_ON(queue_work(cifsiod_wq, &cancelled->work) == false);
773 
774 	return 0;
775 }
776 
777 int
smb2_handle_cancelled_close(struct cifs_tcon * tcon,__u64 persistent_fid,__u64 volatile_fid)778 smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
779 			    __u64 volatile_fid)
780 {
781 	int rc;
782 
783 	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
784 	spin_lock(&cifs_tcp_ses_lock);
785 	if (tcon->tc_count <= 0) {
786 		struct TCP_Server_Info *server = NULL;
787 
788 		WARN_ONCE(tcon->tc_count < 0, "tcon refcount is negative");
789 		spin_unlock(&cifs_tcp_ses_lock);
790 
791 		if (tcon->ses)
792 			server = tcon->ses->server;
793 
794 		cifs_server_dbg(FYI, "tid=%u: tcon is closing, skipping async close retry of fid %llu %llu\n",
795 				tcon->tid, persistent_fid, volatile_fid);
796 
797 		return 0;
798 	}
799 	tcon->tc_count++;
800 	spin_unlock(&cifs_tcp_ses_lock);
801 
802 	rc = __smb2_handle_cancelled_cmd(tcon, SMB2_CLOSE_HE, 0,
803 					 persistent_fid, volatile_fid);
804 	if (rc)
805 		cifs_put_tcon(tcon);
806 
807 	return rc;
808 }
809 
810 int
smb2_handle_cancelled_mid(struct mid_q_entry * mid,struct TCP_Server_Info * server)811 smb2_handle_cancelled_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server)
812 {
813 	struct smb2_sync_hdr *sync_hdr = mid->resp_buf;
814 	struct smb2_create_rsp *rsp = mid->resp_buf;
815 	struct cifs_tcon *tcon;
816 	int rc;
817 
818 	if ((mid->optype & CIFS_CP_CREATE_CLOSE_OP) || sync_hdr->Command != SMB2_CREATE ||
819 	    sync_hdr->Status != STATUS_SUCCESS)
820 		return 0;
821 
822 	tcon = smb2_find_smb_tcon(server, sync_hdr->SessionId,
823 				  sync_hdr->TreeId);
824 	if (!tcon)
825 		return -ENOENT;
826 
827 	rc = __smb2_handle_cancelled_cmd(tcon,
828 					 le16_to_cpu(sync_hdr->Command),
829 					 le64_to_cpu(sync_hdr->MessageId),
830 					 rsp->PersistentFileId,
831 					 rsp->VolatileFileId);
832 	if (rc)
833 		cifs_put_tcon(tcon);
834 
835 	return rc;
836 }
837 
838 /**
839  * smb311_update_preauth_hash - update @ses hash with the packet data in @iov
840  *
841  * Assumes @iov does not contain the rfc1002 length and iov[0] has the
842  * SMB2 header.
843  *
844  * @ses:	server session structure
845  * @iov:	array containing the SMB request we will send to the server
846  * @nvec:	number of array entries for the iov
847  */
848 int
smb311_update_preauth_hash(struct cifs_ses * ses,struct kvec * iov,int nvec)849 smb311_update_preauth_hash(struct cifs_ses *ses, struct kvec *iov, int nvec)
850 {
851 	int i, rc;
852 	struct sdesc *d;
853 	struct smb2_sync_hdr *hdr;
854 	struct TCP_Server_Info *server = cifs_ses_server(ses);
855 
856 	hdr = (struct smb2_sync_hdr *)iov[0].iov_base;
857 	/* neg prot are always taken */
858 	if (hdr->Command == SMB2_NEGOTIATE)
859 		goto ok;
860 
861 	/*
862 	 * If we process a command which wasn't a negprot it means the
863 	 * neg prot was already done, so the server dialect was set
864 	 * and we can test it. Preauth requires 3.1.1 for now.
865 	 */
866 	if (server->dialect != SMB311_PROT_ID)
867 		return 0;
868 
869 	if (hdr->Command != SMB2_SESSION_SETUP)
870 		return 0;
871 
872 	/* skip last sess setup response */
873 	if ((hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
874 	    && (hdr->Status == NT_STATUS_OK
875 		|| (hdr->Status !=
876 		    cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))))
877 		return 0;
878 
879 ok:
880 	rc = smb311_crypto_shash_allocate(server);
881 	if (rc)
882 		return rc;
883 
884 	d = server->secmech.sdescsha512;
885 	rc = crypto_shash_init(&d->shash);
886 	if (rc) {
887 		cifs_dbg(VFS, "%s: Could not init sha512 shash\n", __func__);
888 		return rc;
889 	}
890 
891 	rc = crypto_shash_update(&d->shash, ses->preauth_sha_hash,
892 				 SMB2_PREAUTH_HASH_SIZE);
893 	if (rc) {
894 		cifs_dbg(VFS, "%s: Could not update sha512 shash\n", __func__);
895 		return rc;
896 	}
897 
898 	for (i = 0; i < nvec; i++) {
899 		rc = crypto_shash_update(&d->shash,
900 					 iov[i].iov_base, iov[i].iov_len);
901 		if (rc) {
902 			cifs_dbg(VFS, "%s: Could not update sha512 shash\n",
903 				 __func__);
904 			return rc;
905 		}
906 	}
907 
908 	rc = crypto_shash_final(&d->shash, ses->preauth_sha_hash);
909 	if (rc) {
910 		cifs_dbg(VFS, "%s: Could not finalize sha512 shash\n",
911 			 __func__);
912 		return rc;
913 	}
914 
915 	return 0;
916 }
917