smb: client: let recv_done() avoid touching data_transfer after cleanup/move

Calling enqueue_reassembly() and wake_up_interruptible(&info->wait_reassembly_queue)
or put_receive_buffer() means the response/data_transfer pointer might
get re-used by another thread, which means these should be
the last operations before calling return.

Cc: Steve French <smfrench@gmail.com>
Cc: Tom Talpey <tom@talpey.com>
Cc: Long Li <longli@microsoft.com>
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Fixes: f198186 ("CIFS: SMBD: Establish SMB Direct connection")
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

Author: metze-samba

fs/smb/client/smbdirect.c

@@ -479,10 +479,6 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
 		data_transfer = smbd_response_payload(response);
 		data_length = le32_to_cpu(data_transfer->data_length);
 
-		/*
-		 * If this is a packet with data playload place the data in
-		 * reassembly queue and wake up the reading thread
-		 */
 		if (data_length) {
 			if (info->full_packet_received)
 				response->first_segment = true;
@@ -491,16 +487,7 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
 				info->full_packet_received = false;
 			else
 				info->full_packet_received = true;
-
-			enqueue_reassembly(
-				info,
-				response,
-				data_length);
-		} else
-			put_receive_buffer(info, response);
-
-		if (data_length)
-			wake_up_interruptible(&info->wait_reassembly_queue);
+		}
 
 		atomic_dec(&info->receive_credits);
 		info->receive_credit_target =
@@ -528,6 +515,16 @@ static void recv_done(struct ib_cq *cq, struct ib_wc *wc)
 			info->keep_alive_requested = KEEP_ALIVE_PENDING;
 		}
 
+		/*
+		 * If this is a packet with data playload place the data in
+		 * reassembly queue and wake up the reading thread
+		 */
+		if (data_length) {
+			enqueue_reassembly(info, response, data_length);
+			wake_up_interruptible(&info->wait_reassembly_queue);
+		} else
+			put_receive_buffer(info, response);
+
 		return;
 	}