Added an event for default stable rule "Execution from /dev/shm"

events/syscall/execution_from_dev_shm.go

@@ -0,0 +1,54 @@
+// 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"
+
+	"github.com/falcosecurity/event-generator/events"
+)
+
+var _ = events.Register(ExecutionFromDevShm)
+
+func ExecutionFromDevShm(h events.Helper) error {
+	scriptPath := "/dev/shm/example_script-created-by-falco-event-generator.sh"
+	scriptContent := "#!/bin/bash\n echo 'hello world'"
+
+	// Check if /dev exists
+	if _, err := os.Stat("/dev"); os.IsNotExist(err) {
+		if err := os.Mkdir("/dev/shm", 0755); err != nil {
+			return err
+		}
+		defer os.RemoveAll("/dev") // Remove dev directory
+	}
+
+	// Given /dev exists check if /shm exists
+	if _, err := os.Stat("/dev/shm"); os.IsNotExist(err) {
+		if err := os.Mkdir("/dev/shm", 0755); err != nil {
+			return err
+		}
+		defer os.RemoveAll("/dev/shm") // Remove /shm directory only
+	}
+
+	// Set execute permission on the file
+	if err := os.WriteFile(scriptPath, []byte(scriptContent), 0755); err != nil {
+		return err
+	}
+
+	cmd := exec.Command("sh", "-c", scriptPath) // Execute script file
+	defer os.Remove(scriptPath)                 // Remove script file
+	return cmd.Run()
+}