Merge tag '4.17-rc2-smb3' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "A few security related fixes for SMB3, most importantly for SMB3.11
  encryption"

* tag '4.17-rc2-smb3' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: smbd: Avoid allocating iov on the stack
  cifs: smbd: Don't use RDMA read/write when signing is used
  SMB311: Fix reconnect
  SMB3: Fix 3.11 encryption to Windows and handle encrypted smb3 tcon
  CIFS: set *resp_buf_type to NO_BUFFER on error

fs/cifs/cifssmb.c

@@ -455,6 +455,9 @@ cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
 		server->sign = true;
 	}
 
+	if (cifs_rdma_enabled(server) && server->sign)
+		cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled");
+
 	return 0;
 }
 

fs/cifs/connect.c

@@ -2959,6 +2959,22 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
 		}
 	}
 
+	if (volume_info->seal) {
+		if (ses->server->vals->protocol_id == 0) {
+			cifs_dbg(VFS,
+				 "SMB3 or later required for encryption\n");
+			rc = -EOPNOTSUPP;
+			goto out_fail;
+		} else if (tcon->ses->server->capabilities &
+					SMB2_GLOBAL_CAP_ENCRYPTION)
+			tcon->seal = true;
+		else {
+			cifs_dbg(VFS, "Encryption is not supported on share\n");
+			rc = -EOPNOTSUPP;
+			goto out_fail;
+		}
+	}
+
 	/*
 	 * BB Do we need to wrap session_mutex around this TCon call and Unix
 	 * SetFS as we do on SessSetup and reconnect?
@@ -3007,22 +3023,6 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
 		tcon->use_resilient = true;
 	}
 
-	if (volume_info->seal) {
-		if (ses->server->vals->protocol_id == 0) {
-			cifs_dbg(VFS,
-				 "SMB3 or later required for encryption\n");
-			rc = -EOPNOTSUPP;
-			goto out_fail;
-		} else if (tcon->ses->server->capabilities &
-					SMB2_GLOBAL_CAP_ENCRYPTION)
-			tcon->seal = true;
-		else {
-			cifs_dbg(VFS, "Encryption is not supported on share\n");
-			rc = -EOPNOTSUPP;
-			goto out_fail;
-		}
-	}
-
 	/*
 	 * We can have only one retry value for a connection to a share so for
 	 * resources mounted more than once to the same server share the last

fs/cifs/smb2ops.c

@@ -252,9 +252,14 @@ smb2_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
 	wsize = volume_info->wsize ? volume_info->wsize : CIFS_DEFAULT_IOSIZE;
 	wsize = min_t(unsigned int, wsize, server->max_write);
 #ifdef CONFIG_CIFS_SMB_DIRECT
-	if (server->rdma)
+	if (server->rdma) {
+		if (server->sign)
+			wsize = min_t(unsigned int,
+				wsize, server->smbd_conn->max_fragmented_send_size);
+		else
 			wsize = min_t(unsigned int,
 				wsize, server->smbd_conn->max_readwrite_size);
+	}
 #endif
 	if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
 		wsize = min_t(unsigned int, wsize, SMB2_MAX_BUFFER_SIZE);
@@ -272,9 +277,14 @@ smb2_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
 	rsize = volume_info->rsize ? volume_info->rsize : CIFS_DEFAULT_IOSIZE;
 	rsize = min_t(unsigned int, rsize, server->max_read);
 #ifdef CONFIG_CIFS_SMB_DIRECT
-	if (server->rdma)
+	if (server->rdma) {
+		if (server->sign)
+			rsize = min_t(unsigned int,
+				rsize, server->smbd_conn->max_fragmented_recv_size);
+		else
 			rsize = min_t(unsigned int,
 				rsize, server->smbd_conn->max_readwrite_size);
+	}
 #endif
 
 	if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))

fs/cifs/smb2pdu.c

@@ -383,10 +383,10 @@ static void
 build_encrypt_ctxt(struct smb2_encryption_neg_context *pneg_ctxt)
 {
 	pneg_ctxt->ContextType = SMB2_ENCRYPTION_CAPABILITIES;
-	pneg_ctxt->DataLength = cpu_to_le16(6);
-	pneg_ctxt->CipherCount = cpu_to_le16(2);
-	pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM;
-	pneg_ctxt->Ciphers[1] = SMB2_ENCRYPTION_AES128_CCM;
+	pneg_ctxt->DataLength = cpu_to_le16(4); /* Cipher Count + le16 cipher */
+	pneg_ctxt->CipherCount = cpu_to_le16(1);
+/* pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM;*/ /* not supported yet */
+	pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_CCM;
 }
 
 static void
@@ -444,6 +444,7 @@ static int decode_encrypt_ctx(struct TCP_Server_Info *server,
 		return -EINVAL;
 	}
 	server->cipher_type = ctxt->Ciphers[0];
+	server->capabilities |= SMB2_GLOBAL_CAP_ENCRYPTION;
 	return 0;
 }
 
@@ -2590,7 +2591,7 @@ smb2_new_read_req(void **buf, unsigned int *total_len,
 	 * If we want to do a RDMA write, fill in and append
 	 * smbd_buffer_descriptor_v1 to the end of read request
 	 */
-	if (server->rdma && rdata &&
+	if (server->rdma && rdata && !server->sign &&
 		rdata->bytes >= server->smbd_conn->rdma_readwrite_threshold) {
 
 		struct smbd_buffer_descriptor_v1 *v1;
@@ -2968,7 +2969,7 @@ smb2_async_writev(struct cifs_writedata *wdata,
 	 * If we want to do a server RDMA read, fill in and append
 	 * smbd_buffer_descriptor_v1 to the end of write request
 	 */
-	if (server->rdma && wdata->bytes >=
+	if (server->rdma && !server->sign && wdata->bytes >=
 		server->smbd_conn->rdma_readwrite_threshold) {
 
 		struct smbd_buffer_descriptor_v1 *v1;

fs/cifs/smb2pdu.h

@@ -297,7 +297,7 @@ struct smb2_encryption_neg_context {
 	__le16	DataLength;
 	__le32	Reserved;
 	__le16	CipherCount; /* AES-128-GCM and AES-128-CCM */
-	__le16	Ciphers[2]; /* Ciphers[0] since only one used now */
+	__le16	Ciphers[1]; /* Ciphers[0] since only one used now */
 } __packed;
 
 struct smb2_negotiate_rsp {

fs/cifs/smbdirect.c

@@ -2086,7 +2086,7 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst)
 	int start, i, j;
 	int max_iov_size =
 		info->max_send_size - sizeof(struct smbd_data_transfer);
-	struct kvec iov[SMBDIRECT_MAX_SGE];
+	struct kvec *iov;
 	int rc;
 
 	info->smbd_send_pending++;
@@ -2096,32 +2096,20 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst)
 	}
 
 	/*
-	 * This usually means a configuration error
-	 * We use RDMA read/write for packet size > rdma_readwrite_threshold
-	 * as long as it's properly configured we should never get into this
-	 * situation
-	 */
-	if (rqst->rq_nvec + rqst->rq_npages > SMBDIRECT_MAX_SGE) {
-		log_write(ERR, "maximum send segment %x exceeding %x\n",
-			 rqst->rq_nvec + rqst->rq_npages, SMBDIRECT_MAX_SGE);
-		rc = -EINVAL;
-		goto done;
-	}
-
-	/*
-	 * Remove the RFC1002 length defined in MS-SMB2 section 2.1
-	 * It is used only for TCP transport
+	 * Skip the RFC1002 length defined in MS-SMB2 section 2.1
+	 * It is used only for TCP transport in the iov[0]
 	 * In future we may want to add a transport layer under protocol
 	 * layer so this will only be issued to TCP transport
 	 */
-	iov[0].iov_base = (char *)rqst->rq_iov[0].iov_base + 4;
-	iov[0].iov_len = rqst->rq_iov[0].iov_len - 4;
-	buflen += iov[0].iov_len;
+
+	if (rqst->rq_iov[0].iov_len != 4) {
+		log_write(ERR, "expected the pdu length in 1st iov, but got %zu\n", rqst->rq_iov[0].iov_len);
+		return -EINVAL;
+	}
+	iov = &rqst->rq_iov[1];
 
 	/* total up iov array first */
-	for (i = 1; i < rqst->rq_nvec; i++) {
-		iov[i].iov_base = rqst->rq_iov[i].iov_base;
-		iov[i].iov_len = rqst->rq_iov[i].iov_len;
+	for (i = 0; i < rqst->rq_nvec-1; i++) {
 		buflen += iov[i].iov_len;
 	}
 
@@ -2198,14 +2186,14 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst)
 						goto done;
 				}
 				i++;
-				if (i == rqst->rq_nvec)
+				if (i == rqst->rq_nvec-1)
 					break;
 			}
 			start = i;
 			buflen = 0;
 		} else {
 			i++;
-			if (i == rqst->rq_nvec) {
+			if (i == rqst->rq_nvec-1) {
 				/* send out all remaining vecs */
 				remaining_data_length -= buflen;
 				log_write(INFO,

fs/cifs/transport.c

@@ -753,7 +753,7 @@ cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
 		goto out;
 
 #ifdef CONFIG_CIFS_SMB311
-	if (ses->status == CifsNew)
+	if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP))
 		smb311_update_preauth_hash(ses, rqst->rq_iov+1,
 					   rqst->rq_nvec-1);
 #endif
@@ -798,7 +798,7 @@ cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
 		*resp_buf_type = CIFS_SMALL_BUFFER;
 
 #ifdef CONFIG_CIFS_SMB311
-	if (ses->status == CifsNew) {
+	if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) {
 		struct kvec iov = {
 			.iov_base = buf + 4,
 			.iov_len = get_rfc1002_length(buf)
@@ -834,8 +834,11 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
 	if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
 		new_iov = kmalloc(sizeof(struct kvec) * (n_vec + 1),
 				  GFP_KERNEL);
-		if (!new_iov)
+		if (!new_iov) {
+			/* otherwise cifs_send_recv below sets resp_buf_type */
+			*resp_buf_type = CIFS_NO_BUFFER;
 			return -ENOMEM;
+		}
 	} else
 		new_iov = s_iov;