Add brute force process group clean-up

main.go

@@ -189,6 +189,7 @@ func handleGetInfoRefs(env gitEnv, _ string, path string, w http.ResponseWriter,
 		return
 	}
 	defer cmd.Wait()
+	defer sigKillProcessGroup(cmd) // Ensure brute force subprocess clean-up
 
 	// Start writing the response
 	w.Header().Add("Content-Type", fmt.Sprintf("application/x-%s-advertisement", rpc))
@@ -258,6 +259,7 @@ func handlePostRPC(env gitEnv, rpc string, path string, w http.ResponseWriter, r
 		return
 	}
 	defer cmd.Wait()
+	defer sigKillProcessGroup(cmd) // Ensure brute force subprocess clean-up
 
 	// Write the client request body to Git's standard input
 	if _, err := io.Copy(stdin, body); err != nil {
@@ -296,3 +298,19 @@ func fail500(w http.ResponseWriter, err error) {
 func setHeaderNoCache(w http.ResponseWriter) {
 	w.Header().Add("Cache-Control", "no-cache")
 }
+
+func sigKillProcessGroup(cmd *exec.Cmd) {
+	if cmd == nil {
+		return
+	}
+
+	process := cmd.Process
+	if process == nil {
+		return
+	}
+
+	if process.Pid > 0 {
+		// Send SIGKILL (kill -9) to the process group of cmd
+		syscall.Kill(-process.Pid, syscall.SIGKILL)
+	}
+}