leakhunt/tools/patch_v11_test.py

"""patch_v11_test.py <pid> [--revert]

v11: NULL-check / crash-guard patches for two observed crash sites.

  Site 1 — delete_contents (Barris's crash at 0x0058712f)
    Function at 0x005870f0. Inner trim loop has a state inconsistency
    path that sets EDI=0 and falls through to MOV EAX,[EDI] → AV.
    Patch: change the `JMP +0x07` at 0x00587126 (`eb 07`) to
    `JMP +0x42` (`eb 42`) → jumps to function epilogue at 0x0058716a
    (pop edi; pop esi; ret). Bails on empty-bucket-pass instead of
    UAF.

  Site 2 — ~GXTri3Mesh slot 0 (Kolossos's crash at 0x005e565d)
    Destructor walks 5 subobject slots via vtable. The dereference at
    0x005e565d (`MOV ECX,[EAX]`) crashes when slot pointer is freed.
    Patch: replace the 9-byte deref+call+clear sequence
    (`8b 08 50 ff 51 08 89 5e 08`) with
    `89 5e 08 90 90 90 90 90 90`. Clears the slot but skips the
    virtual call → trades subobject leak for no crash.

This is the v11 patcher. Only patches the ONE slot we've observed
crashing (slot 0 / +0x08 on the mesh). Other slots may need same
treatment if they crash later.
"""
import argparse, ctypes, ctypes.wintypes as wt, sys


SITES = [
    ("site1 delete_contents JMP", 0x00587126,
     bytes([0xEB, 0x07]),
     bytes([0xEB, 0x42])),
    ("site2 ~GXTri3Mesh slot 0",  0x005E565D,
     bytes([0x8B, 0x08, 0x50, 0xFF, 0x51, 0x08, 0x89, 0x5E, 0x08]),
     bytes([0x89, 0x5E, 0x08, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90])),
]


PROCESS_VM_READ = 0x10
PROCESS_VM_WRITE = 0x20
PROCESS_VM_OPERATION = 0x8
PROCESS_QUERY_INFORMATION = 0x400
PAGE_EXECUTE_READWRITE = 0x40

k32 = ctypes.windll.kernel32
OpenProcess = k32.OpenProcess
OpenProcess.argtypes = [wt.DWORD, wt.BOOL, wt.DWORD]; OpenProcess.restype = wt.HANDLE
CloseHandle = k32.CloseHandle
CloseHandle.argtypes = [wt.HANDLE]; CloseHandle.restype = wt.BOOL
WriteProcessMemory = k32.WriteProcessMemory
WriteProcessMemory.argtypes = [wt.HANDLE, wt.LPVOID, wt.LPCVOID, ctypes.c_size_t,
                               ctypes.POINTER(ctypes.c_size_t)]
WriteProcessMemory.restype = wt.BOOL
ReadProcessMemory = k32.ReadProcessMemory
ReadProcessMemory.argtypes = [wt.HANDLE, wt.LPCVOID, wt.LPVOID, ctypes.c_size_t,
                              ctypes.POINTER(ctypes.c_size_t)]
ReadProcessMemory.restype = wt.BOOL
VirtualProtectEx = k32.VirtualProtectEx
VirtualProtectEx.argtypes = [wt.HANDLE, wt.LPVOID, ctypes.c_size_t, wt.DWORD,
                             ctypes.POINTER(wt.DWORD)]
VirtualProtectEx.restype = wt.BOOL


def read_bytes(h, addr, n):
    buf = (ctypes.c_ubyte * n)()
    sz = ctypes.c_size_t(0)
    if not ReadProcessMemory(h, addr, buf, n, ctypes.byref(sz)):
        raise OSError(f"read 0x{addr:08x} err={ctypes.get_last_error()}")
    return bytes(buf[:sz.value])


def write_bytes(h, addr, data):
    old = wt.DWORD(0)
    if not VirtualProtectEx(h, addr, len(data), PAGE_EXECUTE_READWRITE, ctypes.byref(old)):
        raise OSError(f"VirtualProtectEx 0x{addr:08x} err={ctypes.get_last_error()}")
    sz = ctypes.c_size_t(0)
    ok = WriteProcessMemory(h, addr, data, len(data), ctypes.byref(sz))
    err = ctypes.get_last_error() if not ok else 0
    restored = wt.DWORD(0)
    VirtualProtectEx(h, addr, len(data), old.value, ctypes.byref(restored))
    if not ok:
        raise OSError(f"write 0x{addr:08x} err={err}")


def apply_or_revert(h, label, va, orig, patched, revert):
    cur = read_bytes(h, va, len(orig))
    print(f"  {label} @ 0x{va:08x}: current {cur.hex()}")
    if revert:
        if cur == orig:
            print(f"    already original")
        elif cur == patched:
            write_bytes(h, va, orig)
            print(f"    reverted; now: {read_bytes(h, va, len(orig)).hex()}")
        else:
            print(f"    UNEXPECTED bytes — refusing"); sys.exit(3)
        return
    if cur == patched:
        print(f"    already patched")
    elif cur == orig:
        write_bytes(h, va, patched)
        print(f"    patched; now: {read_bytes(h, va, len(orig)).hex()}")
    else:
        print(f"    UNEXPECTED bytes — refusing. Expected: {orig.hex()}")
        sys.exit(4)


def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("pid", type=int)
    ap.add_argument("--revert", action="store_true")
    args = ap.parse_args()
    h = OpenProcess(PROCESS_VM_READ | PROCESS_VM_WRITE | PROCESS_VM_OPERATION |
                    PROCESS_QUERY_INFORMATION, False, args.pid)
    if not h:
        print(f"OpenProcess({args.pid}) err={ctypes.get_last_error()}"); sys.exit(2)
    print(f"PID {args.pid}")
    for label, va, orig, patched in SITES:
        apply_or_revert(h, label, va, orig, patched, args.revert)
    print(f"  OK")
    CloseHandle(h)


if __name__ == "__main__":
    main()