Add SB Curated (copied from the smartbugs repository).

dataset/reentrancy/reentrancy_insecure.sol

@@ -0,0 +1,21 @@
+/*
+ * @source: https://consensys.github.io/smart-contract-best-practices/known_attacks/
+ * @author: consensys
+ * @vulnerable_at_lines: 17
+ */
+
+pragma solidity ^0.4.0;
+
+contract Reentrancy_insecure {
+
+    // INSECURE
+    mapping (address => uint) private userBalances;
+
+    function withdrawBalance() public {
+        uint amountToWithdraw = userBalances[msg.sender];
+        // <yes> <report> REENTRANCY
+        (bool success, ) = msg.sender.call.value(amountToWithdraw)(""); // At this point, the caller's code is executed, and can call withdrawBalance again
+        require(success);
+        userBalances[msg.sender] = 0;
+    }
+}