Merge tag '4.17-rc1SMB3-Fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "SMB3 fixes, a few for stable, and some important cleanup work from
  Ronnie of the smb3 transport code"

* tag '4.17-rc1SMB3-Fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: change validate_buf to validate_iov
  cifs: remove rfc1002 hardcoded constants from cifs_discard_remaining_data()
  cifs: Change SMB2_open to return an iov for the error parameter
  cifs: add resp_buf_size to the mid_q_entry structure
  smb3.11: replace a 4 with server->vals->header_preamble_size
  cifs: replace a 4 with server->vals->header_preamble_size
  cifs: add pdu_size to the TCP_Server_Info structure
  SMB311: Improve checking of negotiate security contexts
  SMB3: Fix length checking of SMB3.11 negotiate request
  CIFS: add ONCE flag for cifs_dbg type
  cifs: Use ULL suffix for 64-bit constant
  SMB3: Log at least once if tree connect fails during reconnect
  cifs: smb2pdu: Fix potential NULL pointer dereference

13 files changed, 240 insertions, 71 deletions

diff --git a/fs/cifs/cifs_debug.c b/fs/cifs/cifs_debug.c
index e35e711..9d69ea4 100644
--- a/fs/cifs/cifs_debug.c
+++ b/fs/cifs/cifs_debug.c
@@ -42,23 +42,6 @@ cifs_dump_mem(char *label, void *data, int length)
 		       data, length, true);
 }
 
-#ifdef CONFIG_CIFS_DEBUG
-void cifs_vfs_err(const char *fmt, ...)
-{
-	struct va_format vaf;
-	va_list args;
-
-	va_start(args, fmt);
-
-	vaf.fmt = fmt;
-	vaf.va = &args;
-
-	pr_err_ratelimited("CIFS VFS: %pV", &vaf);
-
-	va_end(args);
-}
-#endif
-
 void cifs_dump_detail(void *buf)
 {
 #ifdef CONFIG_CIFS_DEBUG2
diff --git a/fs/cifs/cifs_debug.h b/fs/cifs/cifs_debug.h
index c611ca2..fe55676 100644
--- a/fs/cifs/cifs_debug.h
+++ b/fs/cifs/cifs_debug.h
@@ -39,6 +39,7 @@ extern int cifsFYI;
 #else
 #define NOISY 0
 #endif
+#define ONCE 8
 
 /*
  *	debug ON
@@ -46,19 +47,28 @@ extern int cifsFYI;
  */
 #ifdef CONFIG_CIFS_DEBUG
 
-__printf(1, 2) void cifs_vfs_err(const char *fmt, ...);
-
 /* information message: e.g., configuration, major event */
-#define cifs_dbg(type, fmt, ...)					\
-do {									\
-	if (type == FYI && cifsFYI & CIFS_INFO) {			\
-		pr_debug_ratelimited("%s: "				\
-			    fmt, __FILE__, ##__VA_ARGS__);		\
-	} else if (type == VFS) {					\
-		cifs_vfs_err(fmt, ##__VA_ARGS__);			\
-	} else if (type == NOISY && type != 0) {			\
-		pr_debug_ratelimited(fmt, ##__VA_ARGS__);		\
-	}								\
+#define cifs_dbg_func(ratefunc, type, fmt, ...)			\
+do {								\
+	if ((type) & FYI && cifsFYI & CIFS_INFO) {		\
+		pr_debug_ ## ratefunc("%s: "			\
+				fmt, __FILE__, ##__VA_ARGS__);	\
+	} else if ((type) & VFS) {				\
+		pr_err_ ## ratefunc("CuIFS VFS: "		\
+				 fmt, ##__VA_ARGS__);		\
+	} else if ((type) & NOISY && (NOISY != 0)) {		\
+		pr_debug_ ## ratefunc(fmt, ##__VA_ARGS__);	\
+	}							\
+} while (0)
+
+#define cifs_dbg(type, fmt, ...) \
+do {							\
+	if ((type) & ONCE)				\
+		cifs_dbg_func(once,			\
+			 type, fmt, ##__VA_ARGS__);	\
+	else						\
+		cifs_dbg_func(ratelimited,		\
+			type, fmt, ##__VA_ARGS__);	\
 } while (0)
 
 /*
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 2282562..cb950a5 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -665,6 +665,8 @@ struct TCP_Server_Info {
 	struct delayed_work	echo; /* echo ping workqueue job */
 	char	*smallbuf;	/* pointer to current "small" buffer */
 	char	*bigbuf;	/* pointer to current "big" buffer */
+	/* Total size of this PDU. Only valid from cifs_demultiplex_thread */
+	unsigned int pdu_size;
 	unsigned int total_read; /* total amount of data read in this pass */
 #ifdef CONFIG_CIFS_FSCACHE
 	struct fscache_cookie   *fscache; /* client index cache cookie */
@@ -676,6 +678,7 @@ struct TCP_Server_Info {
 	unsigned int	max_read;
 	unsigned int	max_write;
 #ifdef CONFIG_CIFS_SMB311
+	__le16	cipher_type;
 	 /* save initital negprot hash */
 	__u8	preauth_sha_hash[SMB2_PREAUTH_HASH_SIZE];
 #endif /* 3.1.1 */
@@ -1373,6 +1376,7 @@ struct mid_q_entry {
 	mid_handle_t *handle; /* call handle mid callback */
 	void *callback_data;	  /* general purpose pointer for callback */
 	void *resp_buf;		/* pointer to received SMB header */
+	unsigned int resp_buf_size;
 	int mid_state;	/* wish this were enum but can not pass to wait_event */
 	unsigned int mid_flags;
 	__le16 command;		/* smb command code */
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 59c09a5..6d3e40d 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -206,8 +206,10 @@ cifs_reconnect_tcon(struct cifs_tcon *tcon, int smb_command)
 	mutex_unlock(&ses->session_mutex);
 	cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
 
-	if (rc)
+	if (rc) {
+		printk_once(KERN_WARNING "reconnect tcon failed rc = %d\n", rc);
 		goto out;
+	}
 
 	atomic_inc(&tconInfoReconnectCount);
 
@@ -1416,8 +1418,9 @@ openRetry:
 int
 cifs_discard_remaining_data(struct TCP_Server_Info *server)
 {
-	unsigned int rfclen = get_rfc1002_length(server->smallbuf);
-	int remaining = rfclen + 4 - server->total_read;
+	unsigned int rfclen = server->pdu_size;
+	int remaining = rfclen + server->vals->header_preamble_size -
+		server->total_read;
 
 	while (remaining > 0) {
 		int length;
@@ -1454,7 +1457,7 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 	unsigned int data_offset, data_len;
 	struct cifs_readdata *rdata = mid->callback_data;
 	char *buf = server->smallbuf;
-	unsigned int buflen = get_rfc1002_length(buf) +
+	unsigned int buflen = server->pdu_size +
 		server->vals->header_preamble_size;
 	bool use_rdma_mr = false;
 
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 4e0808f..e8830f0 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -772,7 +772,7 @@ standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 {
 	int length;
 	char *buf = server->smallbuf;
-	unsigned int pdu_length = get_rfc1002_length(buf);
+	unsigned int pdu_length = server->pdu_size;
 
 	/* make sure this will fit in a large buffer */
 	if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
@@ -881,6 +881,7 @@ cifs_demultiplex_thread(void *p)
 		 * so we can now interpret the length field.
 		 */
 		pdu_length = get_rfc1002_length(buf);
+		server->pdu_size = pdu_length;
 
 		cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
 		if (!is_smb_response(server, buf[0]))
@@ -927,6 +928,7 @@ cifs_demultiplex_thread(void *p)
 
 		server->lstrp = jiffies;
 		if (mid_entry != NULL) {
+			mid_entry->resp_buf_size = server->pdu_size;
 			if ((mid_entry->mid_flags & MID_WAIT_CANCELLED) &&
 			     mid_entry->mid_state == MID_RESPONSE_RECEIVED &&
 					server->ops->handle_cancelled_mid)
diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index f856df4..3c371f7 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -710,7 +710,7 @@ cgfi_exit:
 /* Simple function to return a 64 bit hash of string.  Rarely called */
 static __u64 simple_hashstr(const char *str)
 {
-	const __u64 hash_mult =  1125899906842597L; /* a big enough prime */
+	const __u64 hash_mult =  1125899906842597ULL; /* a big enough prime */
 	__u64 hash = 0;
 
 	while (*str)
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index 5406e95..68ea849 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -93,6 +93,43 @@ static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
 	/* SMB2_OPLOCK_BREAK */ cpu_to_le16(24)
 };
 
+#ifdef CONFIG_CIFS_SMB311
+static __u32 get_neg_ctxt_len(struct smb2_hdr *hdr, __u32 len, __u32 non_ctxlen,
+				size_t hdr_preamble_size)
+{
+	__u16 neg_count;
+	__u32 nc_offset, size_of_pad_before_neg_ctxts;
+	struct smb2_negotiate_rsp *pneg_rsp = (struct smb2_negotiate_rsp *)hdr;
+
+	/* Negotiate contexts are only valid for latest dialect SMB3.11 */
+	neg_count = le16_to_cpu(pneg_rsp->NegotiateContextCount);
+	if ((neg_count == 0) ||
+	   (pneg_rsp->DialectRevision != cpu_to_le16(SMB311_PROT_ID)))
+		return 0;
+
+	/* Make sure that negotiate contexts start after gss security blob */
+	nc_offset = le32_to_cpu(pneg_rsp->NegotiateContextOffset);
+	if (nc_offset < non_ctxlen - hdr_preamble_size /* RFC1001 len */) {
+		printk_once(KERN_WARNING "invalid negotiate context offset\n");
+		return 0;
+	}
+	size_of_pad_before_neg_ctxts = nc_offset -
+					(non_ctxlen - hdr_preamble_size);
+
+	/* Verify that at least minimal negotiate contexts fit within frame */
+	if (len < nc_offset + (neg_count * sizeof(struct smb2_neg_context))) {
+		printk_once(KERN_WARNING "negotiate context goes beyond end\n");
+		return 0;
+	}
+
+	cifs_dbg(FYI, "length of negcontexts %d pad %d\n",
+		len - nc_offset, size_of_pad_before_neg_ctxts);
+
+	/* length of negcontexts including pad from end of sec blob to them */
+	return (len - nc_offset) + size_of_pad_before_neg_ctxts;
+}
+#endif /* CIFS_SMB311 */
+
 int
 smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr)
 {
@@ -198,6 +235,11 @@ smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr)
 
 	clc_len = smb2_calc_size(hdr);
 
+#ifdef CONFIG_CIFS_SMB311
+	if (shdr->Command == SMB2_NEGOTIATE)
+		clc_len += get_neg_ctxt_len(hdr, len, clc_len,
+					srvr->vals->header_preamble_size);
+#endif /* SMB311 */
 	if (srvr->vals->header_preamble_size + len != clc_len) {
 		cifs_dbg(FYI, "Calculated size %u length %zu mismatch mid %llu\n",
 			 clc_len, srvr->vals->header_preamble_size + len, mid);
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 968b1d43..b4ae932 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -1451,6 +1451,7 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
 	__u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
 	struct cifs_open_parms oparms;
 	struct cifs_fid fid;
+	struct kvec err_iov = {NULL, 0};
 	struct smb2_err_rsp *err_buf = NULL;
 	struct smb2_symlink_err_rsp *symlink;
 	unsigned int sub_len;
@@ -1473,15 +1474,16 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
 	oparms.fid = &fid;
 	oparms.reconnect = false;
 
-	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, &err_buf);
+	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, &err_iov);
 
 	if (!rc || !err_buf) {
 		kfree(utf16_path);
 		return -ENOENT;
 	}
 
+	err_buf = err_iov.iov_base;
 	if (le32_to_cpu(err_buf->ByteCount) < sizeof(struct smb2_symlink_err_rsp) ||
-	    get_rfc1002_length(err_buf) + server->vals->header_preamble_size < SMB2_SYMLINK_STRUCT_SIZE) {
+	    err_iov.iov_len + server->vals->header_preamble_size < SMB2_SYMLINK_STRUCT_SIZE) {
 		kfree(utf16_path);
 		return -ENOENT;
 	}
@@ -1494,13 +1496,13 @@ smb2_query_symlink(const unsigned int xid, struct cifs_tcon *tcon,
 	print_len = le16_to_cpu(symlink->PrintNameLength);
 	print_offset = le16_to_cpu(symlink->PrintNameOffset);
 
-	if (get_rfc1002_length(err_buf) + server->vals->header_preamble_size <
+	if (err_iov.iov_len + server->vals->header_preamble_size <
 			SMB2_SYMLINK_STRUCT_SIZE + sub_offset + sub_len) {
 		kfree(utf16_path);
 		return -ENOENT;
 	}
 
-	if (get_rfc1002_length(err_buf) + server->vals->header_preamble_size <
+	if (err_iov.iov_len + server->vals->header_preamble_size <
 			SMB2_SYMLINK_STRUCT_SIZE + print_offset + print_len) {
 		kfree(utf16_path);
 		return -ENOENT;
@@ -2550,7 +2552,7 @@ receive_encrypted_read(struct TCP_Server_Info *server, struct mid_q_entry **mid)
 	unsigned int npages;
 	struct page **pages;
 	unsigned int len;
-	unsigned int buflen = get_rfc1002_length(buf) + server->vals->header_preamble_size;
+	unsigned int buflen = server->pdu_size + server->vals->header_preamble_size;
 	int rc;
 	int i = 0;
 
@@ -2624,7 +2626,7 @@ receive_encrypted_standard(struct TCP_Server_Info *server,
 {
 	int length;
 	char *buf = server->smallbuf;
-	unsigned int pdu_length = get_rfc1002_length(buf);
+	unsigned int pdu_length = server->pdu_size;
 	unsigned int buf_size;
 	struct mid_q_entry *mid_entry;
 
@@ -2668,7 +2670,7 @@ static int
 smb3_receive_transform(struct TCP_Server_Info *server, struct mid_q_entry **mid)
 {
 	char *buf = server->smallbuf;
-	unsigned int pdu_length = get_rfc1002_length(buf);
+	unsigned int pdu_length = server->pdu_size;
 	struct smb2_transform_hdr *tr_hdr = (struct smb2_transform_hdr *)buf;
 	unsigned int orig_len = le32_to_cpu(tr_hdr->OriginalMessageSize);
 
@@ -2699,7 +2701,7 @@ smb3_handle_read_data(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 {
 	char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
 
-	return handle_read_data(server, mid, buf, get_rfc1002_length(buf) +
+	return handle_read_data(server, mid, buf, server->pdu_size +
 				server->vals->header_preamble_size,
 				NULL, 0, 0);
 }
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index f7741ce..0f044c4 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -268,8 +268,11 @@ smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
 	mutex_unlock(&tcon->ses->session_mutex);
 
 	cifs_dbg(FYI, "reconnect tcon rc = %d\n", rc);
-	if (rc)
+	if (rc) {
+		/* If sess reconnected but tcon didn't, something strange ... */
+		printk_once(KERN_WARNING "reconnect tcon failed rc = %d\n", rc);
 		goto out;
+	}
 
 	if (smb2_command != SMB2_INTERNAL_CMD)
 		queue_delayed_work(cifsiod_wq, &server->reconnect, 0);
@@ -403,6 +406,100 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 	*total_len += 4 + sizeof(struct smb2_preauth_neg_context)
 		+ sizeof(struct smb2_encryption_neg_context);
 }
+
+static void decode_preauth_context(struct smb2_preauth_neg_context *ctxt)
+{
+	unsigned int len = le16_to_cpu(ctxt->DataLength);
+
+	/* If invalid preauth context warn but use what we requested, SHA-512 */
+	if (len < MIN_PREAUTH_CTXT_DATA_LEN) {
+		printk_once(KERN_WARNING "server sent bad preauth context\n");
+		return;
+	}
+	if (le16_to_cpu(ctxt->HashAlgorithmCount) != 1)
+		printk_once(KERN_WARNING "illegal SMB3 hash algorithm count\n");
+	if (ctxt->HashAlgorithms != SMB2_PREAUTH_INTEGRITY_SHA512)
+		printk_once(KERN_WARNING "unknown SMB3 hash algorithm\n");
+}
+
+static int decode_encrypt_ctx(struct TCP_Server_Info *server,
+			      struct smb2_encryption_neg_context *ctxt)
+{
+	unsigned int len = le16_to_cpu(ctxt->DataLength);
+
+	cifs_dbg(FYI, "decode SMB3.11 encryption neg context of len %d\n", len);
+	if (len < MIN_ENCRYPT_CTXT_DATA_LEN) {
+		printk_once(KERN_WARNING "server sent bad crypto ctxt len\n");
+		return -EINVAL;
+	}
+
+	if (le16_to_cpu(ctxt->CipherCount) != 1) {
+		printk_once(KERN_WARNING "illegal SMB3.11 cipher count\n");
+		return -EINVAL;
+	}
+	cifs_dbg(FYI, "SMB311 cipher type:%d\n", le16_to_cpu(ctxt->Ciphers[0]));
+	if ((ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_CCM) &&
+	    (ctxt->Ciphers[0] != SMB2_ENCRYPTION_AES128_GCM)) {
+		printk_once(KERN_WARNING "invalid SMB3.11 cipher returned\n");
+		return -EINVAL;
+	}
+	server->cipher_type = ctxt->Ciphers[0];
+	return 0;
+}
+
+static int smb311_decode_neg_context(struct smb2_negotiate_rsp *rsp,
+				     struct TCP_Server_Info *server)
+{
+	struct smb2_neg_context *pctx;
+	unsigned int offset = le32_to_cpu(rsp->NegotiateContextOffset);
+	unsigned int ctxt_cnt = le16_to_cpu(rsp->NegotiateContextCount);
+	unsigned int len_of_smb = be32_to_cpu(rsp->hdr.smb2_buf_length);
+	unsigned int len_of_ctxts, i;
+	int rc = 0;
+
+	cifs_dbg(FYI, "decoding %d negotiate contexts\n", ctxt_cnt);
+	if (len_of_smb <= offset) {
+		cifs_dbg(VFS, "Invalid response: negotiate context offset\n");
+		return -EINVAL;
+	}
+
+	len_of_ctxts = len_of_smb - offset;
+
+	for (i = 0; i < ctxt_cnt; i++) {
+		int clen;
+		/* check that offset is not beyond end of SMB */
+		if (len_of_ctxts == 0)
+			break;
+
+		if (len_of_ctxts < sizeof(struct smb2_neg_context))
+			break;
+
+		pctx = (struct smb2_neg_context *)(offset +
+			server->vals->header_preamble_size + (char *)rsp);
+		clen = le16_to_cpu(pctx->DataLength);
+		if (clen > len_of_ctxts)
+			break;
+
+		if (pctx->ContextType == SMB2_PREAUTH_INTEGRITY_CAPABILITIES)
+			decode_preauth_context(
+				(struct smb2_preauth_neg_context *)pctx);
+		else if (pctx->ContextType == SMB2_ENCRYPTION_CAPABILITIES)
+			rc = decode_encrypt_ctx(server,
+				(struct smb2_encryption_neg_context *)pctx);
+		else
+			cifs_dbg(VFS, "unknown negcontext of type %d ignored\n",
+				le16_to_cpu(pctx->ContextType));
+
+		if (rc)
+			break;
+		/* offsets must be 8 byte aligned */
+		clen = (clen + 7) & ~0x7;
+		offset += clen + sizeof(struct smb2_neg_context);
+		len_of_ctxts -= clen;
+	}
+	return rc;
+}
+
 #else
 static void assemble_neg_contexts(struct smb2_negotiate_req *req,
 				  unsigned int *total_len)
@@ -616,6 +713,15 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
 		else if (rc == 0)
 			rc = -EIO;
 	}
+
+#ifdef CONFIG_CIFS_SMB311
+	if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID)) {
+		if (rsp->NegotiateContextCount)
+			rc = smb311_decode_neg_context(rsp, server);
+		else
+			cifs_dbg(VFS, "Missing expected negotiate contexts\n");
+	}
+#endif /* CONFIG_CIFS_SMB311 */
 neg_exit:
 	free_rsp_buf(resp_buftype, rsp);
 	return rc;
@@ -1026,7 +1132,7 @@ SMB2_sess_auth_rawntlmssp_negotiate(struct SMB2_sess_data *sess_data)
 	if (rc)
 		goto out;
 
-	if (offsetof(struct smb2_sess_setup_rsp, Buffer) - 4 !=
+	if (offsetof(struct smb2_sess_setup_rsp, Buffer) - ses->server->vals->header_preamble_size !=
 			le16_to_cpu(rsp->SecurityBufferOffset)) {
 		cifs_dbg(VFS, "Invalid security buffer offset %d\n",
 			le16_to_cpu(rsp->SecurityBufferOffset));
@@ -1701,7 +1807,7 @@ alloc_path_with_tree_prefix(__le16 **out_path, int *out_size, int *out_len,
 int
 SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
 	  __u8 *oplock, struct smb2_file_all_info *buf,
-	  struct smb2_err_rsp **err_buf)
+	  struct kvec *err_iov)
 {
 	struct smb2_create_req *req;
 	struct smb2_create_rsp *rsp;
@@ -1841,9 +1947,11 @@ SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms, __le16 *path,
 
 	if (rc != 0) {
 		cifs_stats_fail_inc(tcon, SMB2_CREATE_HE);
-		if (err_buf && rsp)
-			*err_buf = kmemdup(rsp, get_rfc1002_length(rsp) + 4,
-					   GFP_KERNEL);
+		if (err_iov && rsp) {
+			*err_iov = rsp_iov;
+			resp_buftype = CIFS_NO_BUFFER;
+			rsp = NULL;
+		}
 		goto creat_exit;
 	}
 
@@ -2098,13 +2206,13 @@ close_exit:
 }
 
 static int
-validate_buf(unsigned int offset, unsigned int buffer_length,
-	     struct smb2_hdr *hdr, unsigned int min_buf_size)
-
+validate_iov(struct TCP_Server_Info *server,
+	     unsigned int offset, unsigned int buffer_length,
+	     struct kvec *iov, unsigned int min_buf_size)
 {
-	unsigned int smb_len = be32_to_cpu(hdr->smb2_buf_length);
-	char *end_of_smb = smb_len + 4 /* RFC1001 length field */ + (char *)hdr;
-	char *begin_of_buf = 4 /* RFC1001 len field */ + offset + (char *)hdr;
+	unsigned int smb_len = iov->iov_len;
+	char *end_of_smb = smb_len + server->vals->header_preamble_size + (char *)iov->iov_base;
+	char *begin_of_buf = server->vals->header_preamble_size + offset + (char *)iov->iov_base;
 	char *end_of_buf = begin_of_buf + buffer_length;
 
 
@@ -2134,18 +2242,18 @@ validate_buf(unsigned int offset, unsigned int buffer_length,
  * Caller must free buffer.
  */
 static int
-validate_and_copy_buf(unsigned int offset, unsigned int buffer_length,
-		      struct smb2_hdr *hdr, unsigned int minbufsize,
+validate_and_copy_iov(struct TCP_Server_Info *server,
+		      unsigned int offset, unsigned int buffer_length,
+		      struct kvec *iov, unsigned int minbufsize,
 		      char *data)
-
 {
-	char *begin_of_buf = 4 /* RFC1001 len field */ + offset + (char *)hdr;
+	char *begin_of_buf = server->vals->header_preamble_size + offset + (char *)(iov->iov_base);
 	int rc;
 
 	if (!data)
 		return -EINVAL;
 
-	rc = validate_buf(offset, buffer_length, hdr, minbufsize);
+	rc = validate_iov(server, offset, buffer_length, iov, minbufsize);
 	if (rc)
 		return rc;
 
@@ -2223,9 +2331,10 @@ query_info(const unsigned int xid, struct cifs_tcon *tcon,
 		}
 	}
 
-	rc = validate_and_copy_buf(le16_to_cpu(rsp->OutputBufferOffset),
+	rc = validate_and_copy_iov(ses->server,
+				   le16_to_cpu(rsp->OutputBufferOffset),
 				   le32_to_cpu(rsp->OutputBufferLength),
-				   &rsp->hdr, min_len, *data);
+				   &rsp_iov, min_len, *data);
 
 qinf_exit:
 	free_rsp_buf(resp_buftype, rsp);
@@ -3146,8 +3255,9 @@ SMB2_query_directory(const unsigned int xid, struct cifs_tcon *tcon,
 		goto qdir_exit;
 	}
 
-	rc = validate_buf(le16_to_cpu(rsp->OutputBufferOffset),
-			  le32_to_cpu(rsp->OutputBufferLength), &rsp->hdr,
+	rc = validate_iov(server,
+			  le16_to_cpu(rsp->OutputBufferOffset),
+			  le32_to_cpu(rsp->OutputBufferLength), &rsp_iov,
 			  info_buf_size);
 	if (rc)
 		goto qdir_exit;
@@ -3454,7 +3564,7 @@ static int
 build_qfs_info_req(struct kvec *iov, struct cifs_tcon *tcon, int level,
 		   int outbuf_len, u64 persistent_fid, u64 volatile_fid)
 {
-	struct TCP_Server_Info *server = tcon->ses->server;
+	struct TCP_Server_Info *server;
 	int rc;
 	struct smb2_query_info_req *req;
 	unsigned int total_len;
@@ -3464,6 +3574,8 @@ build_qfs_info_req(struct kvec *iov, struct cifs_tcon *tcon, int level,
 	if ((tcon->ses == NULL) || (tcon->ses->server == NULL))
 		return -EIO;
 
+	server = tcon->ses->server;
+
 	rc = smb2_plain_req_init(SMB2_QUERY_INFO, tcon, (void **) &req,
 			     &total_len);
 	if (rc)
@@ -3517,8 +3629,9 @@ SMB2_QFS_info(const unsigned int xid, struct cifs_tcon *tcon,
 
 	info = (struct smb2_fs_full_size_info *)(server->vals->header_preamble_size +
 		le16_to_cpu(rsp->OutputBufferOffset) + (char *)&rsp->hdr);
-	rc = validate_buf(le16_to_cpu(rsp->OutputBufferOffset),
-			  le32_to_cpu(rsp->OutputBufferLength), &rsp->hdr,
+	rc = validate_iov(server,
+			  le16_to_cpu(rsp->OutputBufferOffset),
+			  le32_to_cpu(rsp->OutputBufferLength), &rsp_iov,
 			  sizeof(struct smb2_fs_full_size_info));
 	if (!rc)
 		copy_fs_info_to_kstatfs(info, fsdata);
@@ -3574,7 +3687,7 @@ SMB2_QFS_attr(const unsigned int xid, struct cifs_tcon *tcon,
 
 	rsp_len = le32_to_cpu(rsp->OutputBufferLength);
 	offset = le16_to_cpu(rsp->OutputBufferOffset);
-	rc = validate_buf(offset, rsp_len, &rsp->hdr, min_len);
+	rc = validate_iov(server, offset, rsp_len, &rsp_iov, min_len);
 	if (rc)
 		goto qfsattr_exit;
 
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 253e2c7..6093e51 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -263,11 +263,19 @@ struct smb2_negotiate_req {
 #define SMB2_NT_FIND			0x00100000
 #define SMB2_LARGE_FILES		0x00200000
 
+struct smb2_neg_context {
+	__le16	ContextType;
+	__le16	DataLength;
+	__le32	Reserved;
+	/* Followed by array of data */
+} __packed;
+
 #define SMB311_SALT_SIZE			32
 /* Hash Algorithm Types */
 #define SMB2_PREAUTH_INTEGRITY_SHA512	cpu_to_le16(0x0001)
 #define SMB2_PREAUTH_HASH_SIZE 64
 
+#define MIN_PREAUTH_CTXT_DATA_LEN	(SMB311_SALT_SIZE + 6)
 struct smb2_preauth_neg_context {
 	__le16	ContextType; /* 1 */
 	__le16	DataLength;
@@ -282,6 +290,8 @@ struct smb2_preauth_neg_context {
 #define SMB2_ENCRYPTION_AES128_CCM	cpu_to_le16(0x0001)
 #define SMB2_ENCRYPTION_AES128_GCM	cpu_to_le16(0x0002)
 
+/* Min encrypt context data is one cipher so 2 bytes + 2 byte count field */
+#define MIN_ENCRYPT_CTXT_DATA_LEN	4
 struct smb2_encryption_neg_context {
 	__le16	ContextType; /* 2 */
 	__le16	DataLength;
diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
index cbcce3f..8ba24a9 100644
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -122,7 +122,7 @@ extern int SMB2_tdis(const unsigned int xid, struct cifs_tcon *tcon);
 extern int SMB2_open(const unsigned int xid, struct cifs_open_parms *oparms,
 		     __le16 *path, __u8 *oplock,
 		     struct smb2_file_all_info *buf,
-		     struct smb2_err_rsp **err_buf);
+		     struct kvec *err_iov);
 extern int SMB2_ioctl(const unsigned int xid, struct cifs_tcon *tcon,
 		     u64 persistent_fid, u64 volatile_fid, u32 opcode,
 		     bool is_fsctl, char *in_data, u32 indatalen,
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index bf49cb7..8806f3f 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -604,7 +604,7 @@ int
 smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 		   bool log_error)
 {
-	unsigned int len = get_rfc1002_length(mid->resp_buf);
+	unsigned int len = mid->resp_buf_size;
 	struct kvec iov[2];
 	struct smb_rqst rqst = { .rq_iov = iov,
 				 .rq_nvec = 2 };
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 279718d..8f6f259 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -790,7 +790,7 @@ cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
 
 	buf = (char *)midQ->resp_buf;
 	resp_iov->iov_base = buf;
-	resp_iov->iov_len = get_rfc1002_length(buf) +
+	resp_iov->iov_len = midQ->resp_buf_size +
 		ses->server->vals->header_preamble_size;
 	if (midQ->large_buf)
 		*resp_buf_type = CIFS_LARGE_BUFFER;