- Syscall parameter validation
- Panic on invalid operations
- No libc (reduces attack surface)
- Higher-half kernel (user/kernel isolation)
- NX Enforcement: XD bit in page tables for non-executable data
- ASLR: Randomize kernel heap and stack allocations
- Stack Canaries: Magic values to detect buffer overflows
- SMAP/SMEP: Hardware-enforced user/kernel access control
- Capability System: Fine-grained permissions for syscalls
- Stack Canaries: Magic values in task structs, validated on context switches
- NX Enforcement: XD bit support in paging for non-executable pages
- ASLR: Basic randomization in kernel heap allocations
- Syscall Filtering: Parameter validation and bounds checking
- Memory Safety: Bounds checking in allocators and I/O operations
struct task {
// ...
uint64_t canary;
// ...
};
// Set on task creation
task->canary = 0xDEADBEEFDEADBEEF;
// Check on context switch
if (current_task->canary != 0xDEADBEEFDEADBEEF) {
panic("Stack corruption detected");
}// In paging.c map_page()
if (!(flags & EXEC)) {
flags |= XD; // Non-executable
}void syscall_dispatch(uint64_t num, uint64_t arg1, uint64_t arg2, uint64_t arg3) {
// Bounds checking
if (num >= MAX_SYSCALLS) {
return -EINVAL;
}
// Parameter validation per syscall
}
- Buffer overflow detection (canary checks)
- Invalid syscall handling
- Memory corruption prevention
- Crash analysis with secure panic recovery
- Linux kernel security best practices
- No known vulnerabilities in implemented code
- Defense-in-depth approach
- Regular security audits
- Minimal: No network services, no user input parsing
- Isolated: Kernel-only, no userspace services
- Audited: All code reviewed for security issues
- Implement SMEP/SMAP in CR4
- Add full ASLR with entropy sources
- Develop capability-based security model
- Add runtime exploit detection
- Hardware security feature enablement