How Can I Execute a Binary from Memory Without Writing to Disk?

Executing Binaries from Memory Without Disk Writeback

In your program, you have embedded a binary within a variable and are seeking a way to execute it without disk writeback. This involves finding a mechanism to execute the binary directly from memory.

C/C Approach (Using mprotect() System Call)

Using C or C (via CGO in Go), you can leverage the mprotect() system call in Linux to manipulate memory protection. This call allows you to change the permissions of a memory region, making it executable. Once the region is protected as executable, you can execute it by jumping into it.

#include <sys>

int main() {
  // ... (Load binary into memory)

  // Change memory protection to executable
  mprotect(binary_buffer, binary_size, PROT_READ | PROT_WRITE | PROT_EXEC);

  // Jump into the executable region
  ((void (*)(void))binary_buffer)();
}</sys>

Go Approach (Assembly Techniques)

In Go, there are no direct system calls that allow you to specify memory protection. However, you can use assembly techniques to manipulate the memory protection using the syscall.Syscall function to invoke the mprotect() system call from Go code.

import (
  "syscall"
  "unsafe"
)

// ... (Load binary into memory)

// Change memory protection to executable
syscall.Syscall(syscall.SYS_MPROTECT, uintptr(unsafe.Pointer(&binary_buffer[0])), uintptr(binary_size), syscall.PROT_READ|syscall.PROT_WRITE|syscall.PROT_EXEC)

// Jump into the executable region
(((func()) unsafe.Pointer(&binary_buffer[0])))()

Note:

• The techniques mentioned above are platform-specific and may only work on Linux systems.
• You should carefully consider the implications of executing code directly from memory, as it can lead to security vulnerabilities.
• It's important to exercise caution when manipulating memory permissions and ensure that all necessary checks are in place to prevent unintended behavior.

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