Security Policy for VirtMemU (Virtual Memory Utility) This document outlines the security considerations for VirtMemU, a simple C utility designed to display the top 10 memory-intensive processes on Unix-like systems by reading virtual memory usage (VmSize) from the /proc filesystem. Developed for educational purposes, VirtMemU explores C programming, POSIX system interfaces, and memory management. While not intended for production environments, understanding its security profile enhances the learning experience. Supported Versions VirtMemU is a single-version educational project with no official releases or versioned support. The latest code reflects its state as of February 23, 2025. Version

Supported Latest

✅ (Educational) Security Considerations Overview VirtMemU is a standalone, non-networked tool with these security-relevant traits:

Reads process metadata (PID, name, VmSize) from /proc/[pid]/status. Uses dynamic memory allocation (malloc, realloc) and sorts data with qsort. Executes locally without external input or network connectivity.

Potential Vulnerabilities

Privilege Escalation via /proc Access: Risk: Requires read permissions for /proc/[pid]/status. Running as root exposes all processes (including system ones), potentially leaking sensitive data (e.g., kernel thread info), though no execution is possible. Severity: Low (visibility only, no control). Buffer Overflow Risks: Risk: Fixed-size buffers (e.g., char path[256], char name[16]) could overflow if /proc data exceeds limits (e.g., unusually long process names). Current use of snprintf, strncpy, and size limits mitigates this. Status: Controlled by bounds checking. Severity: Low (current code safe). Memory Management Issues: Risk: Allocation failures (malloc, realloc) could crash the program if not handled. Current code exits gracefully on failure, but leaks could occur in future modifications. Severity: Low (local impact). Race Conditions in /proc Reads: Risk: Process termination during /proc scanning might skip entries or read partial data. No significant impact as it’s a snapshot tool. Severity: Negligible (educational use). Unvalidated /proc Data: Risk: Assumes /proc/[pid]/status contains expected fields (Name, VmSize). Malformed entries (rare, requires root manipulation) could disrupt parsing. Severity: Low (system tampering needed).

Mitigation Strategies

Privilege Management: Run as a non-root user to limit visibility to user-owned processes. Avoid unnecessary sudo execution unless inspecting all system processes. Buffer Protection: Maintain use of snprintf with size limits (e.g., sizeof(path)) and strncpy for name copying with null-termination.

Example: c

snprintf(path, sizeof(path), "/proc/%s/status", pid_str);
strncpy(proc_info->name, proc_name, sizeof(proc_info->name) - 1);

Memory Safety:

Ensure allocation checks and cleanup: c

if (!processes) { perror("Failed to allocate memory"); exit(EXIT_FAILURE); }
free(processes);

Handle realloc failures similarly.

Race Conditions:

Accept as a design limitation for simplicity. For learning, optionally add a retry loop if fopen fails mid-scan.

Data Validation:

Current numeric PID check (strspn) is adequate. Additional checks (e.g., VmSize presence) ensure data integrity: c

    if (proc_name[0] && vm_size > 0) { ... }

No external input, so no sanitization needed. Execution Context: No network exposure eliminates remote risks. Restrict to trusted systems (e.g., personal Linux machine).

Reporting a Vulnerability As an educational project, VirtMemU welcomes security feedback for learning:

How to Report: Submit issues via my mail [xenonquake@gmail.com] - Include vulnerability details, reproduction steps, and impact. Response Time: Informal responses expected within a week, depending on availability.

Recommendations for Safe Use

Educational Use: Run on a personal/test system to explore /proc and process memory safely. User Privileges: Execute as a regular user to avoid exposing system process details.

Debugging: Add verbose logging in get_process_info for troubleshooting: c

printf("Reading PID: %s\n", pid_str);

Not for Production: Use established tools (e.g., top, htop) for critical monitoring.

Known Issues from Development

Access Denied: Some /proc/[pid]/status files may be unreadable (e.g., system processes). Skipped silently with return 1. Truncated Names: Process names longer than 15 characters are cut off due to char name[16], a minor display limitation.

Future Security Enhancements For educational exploration:

Add stricter /proc data validation (e.g., check file format consistency). Simulate buffer overflow scenarios to study mitigation (e.g., increase name size). Explore memory hardening (e.g., custom allocator with bounds checking).