Handle long commands safely in parser

src/RequestParser.cpp

@@ -470,6 +470,8 @@ void RequestParser::parseCmd()
     if (mArgLen >= Const::MaxCmdLen) {
         mStatus = CmdError;
         mType = Command::None;
+        // Keep mCommand non-null for downstream state handling.
+        mCommand = &Command::get(Command::None);
         logNotice("unknown request cmd too long:%s...", mCmd);
         return;
     }

test/request_parser_long_command.py

@@ -0,0 +1,34 @@
+#!/usr/bin/env python3
+#
+# Send an overlong command name to ensure parser doesn't crash.
+#
+
+import socket
+from test_util import parse_args, make_client, exit_with_result
+
+
+def run_test(host, port):
+    long_cmd = b"a" * 32
+    payload = b"*2\r\n$32\r\n" + long_cmd + b"\r\n$1\r\nx\r\n"
+    try:
+        sock = socket.create_connection((host, port), timeout=1.0)
+        sock.sendall(payload)
+        sock.close()
+    except Exception as exc:
+        print("WARN: long command send failed:", exc)
+
+    try:
+        c = make_client(host, port)
+        if c.ping() is not True:
+            print("FAIL: ping after long command")
+            return False
+    except Exception as exc:
+        print("FAIL: ping after long command:", exc)
+        return False
+    return True
+
+
+if __name__ == "__main__":
+    args = parse_args("Request parser long command test")
+    success = run_test(args.host, args.port)
+    exit_with_result(success, "request parser long command", "request parser long command")

test/run.sh

@@ -143,6 +143,7 @@ TESTS=(
     "test/request_parser_boundary.py"
     "test/request_parser_error_log.py"
     "test/response_parser_error_log.py"
+    "test/request_parser_long_command.py"
     "test/pubsub_long_name.py"
     "test/pubsub_large_message.py"
     "test/transaction_forbid.py"