WIP: Added an event for default stable rule "Linux Kernel Module Injection Detected"

events/syscall/linux_kernel_module_injection.go

@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: Apache-2.0
+/*
+Copyright (C) 2024 The Falco Authors.
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+    http://www.apache.org/licenses/LICENSE-2.0
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package syscall
+
+import (
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"github.com/falcosecurity/event-generator/events"
+)
+
+var _ = events.Register(LinuxKernelModuleInjection)
+
+func LinuxKernelModuleInjection(h events.Helper) error {
+	if h.InContainer() {
+		// Create a unique temp directory
+		tempDirectoryName, err := os.MkdirTemp("/home", "falco-event-generator-")
+		if err != nil {
+			return err
+		}
+		defer os.RemoveAll(tempDirectoryName)
+
+		// Create a c file and make file for building a kernel module
+		cFilePath := filepath.Join(tempDirectoryName, "basic_driver.c")
+		cFileContent := `#include <linux/init.h>
+		#include <linux/module.h>
+		#include <linux/uaccess.h>
+		#include <linux/fs.h>
+		#include <linux/proc_fs.h>
+
+		// Module metadata
+		MODULE_AUTHOR("Falco");
+		MODULE_DESCRIPTION("Hello world driver for falco");
+		MODULE_LICENSE("GPL");
+
+		static int __init custom_init(void) {
+			printk(KERN_INFO "Hello from Basic kernel module.");
+			return 0;
+		}
+		static void __exit custom_exit(void) {
+			printk(KERN_INFO "Exit the kernel module");
+		}
+
+		module_init(custom_init);
+		module_exit(custom_exit);
+		`
+
+		if err := os.WriteFile(cFilePath, []byte(cFileContent), 0644); err != nil {
+			return err
+		}
+
+		makefilePath := filepath.Join(tempDirectoryName, "Makefile")
+		makefileContent := `obj-m += basic_driver.o
+
+		all:
+			make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
+		clean:
+			make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean`
+
+		if err := os.WriteFile(makefilePath, []byte(makefileContent), 0644); err != nil {
+			return err
+		}
+
+		// Run make command
+		cmd := exec.Command("make")
+		cmd.Dir = tempDirectoryName
+		if err := cmd.Run(); err != nil {
+			return err
+		}
+
+		// Load kernel module with insmod
+		koFilePath := filepath.Join(tempDirectoryName, "basic_driver.ko")
+		defer exec.Command("rmmod", "basic_driver.ko") // Unload the kernel module at end
+		return exec.Command("insmod", koFilePath).Run()
+	}
+	return nil
+}