fetch_ml/native/tests/fuzz/fuzz_file_hash.cpp
Jeremie Fraeys 7efe8bbfbf
native: security hardening, research trustworthiness, and CVE mitigations
Security Fixes:
- CVE-2024-45339: Add O_EXCL flag to temp file creation in storage_write_entries()
  Prevents symlink attacks on predictable .tmp file paths
- CVE-2025-47290: Use openat_nofollow() in storage_open()
  Closes TOCTOU race condition via path_sanitizer infrastructure
- CVE-2025-0838: Add MAX_BATCH_SIZE=10000 to add_tasks()
  Prevents integer overflow in batch operations

Research Trustworthiness (dataset_hash):
- Deterministic file ordering: std::sort after collect_files()
- Recursive directory traversal: depth-limited with cycle detection
- Documented exclusions: hidden files and special files noted in API

Bug Fixes:
- R1: storage_init path validation for non-existent directories
- R2: safe_strncpy return value check before strcat
- R3: parallel_hash 256-file cap replaced with std::vector
- R4: wire qi_compact_index/qi_rebuild_index stubs
- R5: CompletionLatch race condition fix (hold mutex during decrement)
- R6: ARMv8 SHA256 transform fix (save abcd_pre before vsha256hq_u32)
- R7: fuzz_index_storage header format fix
- R8: enforce null termination in add_tasks/update_tasks
- R9: use 64 bytes (not 65) in combined hash to exclude null terminator
- R10: status field persistence in save()

New Tests:
- test_recursive_dataset.cpp: Verify deterministic recursive hashing
- test_storage_symlink_resistance.cpp: Verify CVE-2024-45339 fix
- test_queue_index_batch_limit.cpp: Verify CVE-2025-0838 fix
- test_sha256_arm_kat.cpp: ARMv8 known-answer tests
- test_storage_init_new_dir.cpp: F1 verification
- test_parallel_hash_large_dir.cpp: F3 verification
- test_queue_index_compact.cpp: F4 verification

All 8 native tests passing. Library ready for research lab deployment.
2026-02-21 13:33:45 -05:00

49 lines
1.2 KiB
C++

// fuzz_file_hash.cpp - libFuzzer harness for file hashing
// Tests hash_file with arbitrary file content
#include <cstdint>
#include <cstddef>
#include <cstdio>
#include <cstring>
#include <unistd.h>
#include <fcntl.h>
// Include the file hash implementation
#include "../../dataset_hash/io/file_hash.h"
extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
// Create a temporary file
char tmpfile[] = "/tmp/fuzz_hash_XXXXXX";
int fd = mkstemp(tmpfile);
if (fd < 0) {
return 0;
}
// Write fuzz data
write(fd, data, size);
close(fd);
// Try to hash the file
char hash[65];
int result = hash_file(tmpfile, 64 * 1024, hash);
// Verify: if success, hash must be 64 hex chars
if (result == 0) {
// Check all characters are valid hex
for (int i = 0; i < 64; i++) {
char c = hash[i];
if (!((c >= '0' && c <= '9') || (c >= 'a' && c <= 'f'))) {
__builtin_trap(); // Invalid hash format
}
}
// Must be null-terminated at position 64
if (hash[64] != '\0') {
__builtin_trap();
}
}
// Cleanup
unlink(tmpfile);
return 0; // Non-crashing input
}