def mmapx(sm, p, syscall_name, args, offset):
MAP_SHARED = 0x1
memory_region_name = syscall_name
handle = sm.z.handles.get(args.fd)
if handle is not None:
memory_region_name = f"{syscall_name} -> {handle.Name}"
addr = args.addr
if addr == 0:
addr = p.memory._find_free_space(args.length)
data = b""
if handle is not None:
f = sm.z.files.open_library(handle.Name)
if f is not None:
f.seek(offset)
data = f.read(args.length)
f.close()
data += b"\0" * (args.length - len(data))
# If this is shared, map it with the pointer
if args.flags & MAP_SHARED != 0:
print(len(data))
ptr = ctypes.POINTER(ctypes.c_void_p)(ctypes.c_void_p.from_buffer(
bytearray(data)))
p.memory.map(
addr,
align(args.length),
name=memory_region_name,
kind=syscall_name,
ptr=ptr,
)
return addr
try:
p.memory.map(
addr,
align(args.length),
name=memory_region_name,
kind=syscall_name,
)
except Exception:
if args.flags & 0x10 > 0:
# This must be mapped to this region, we should be able to
# just write over the existing data.
# This should crash if we are unable to write to the desired
# region
pass
else:
sm.logger.notice(f"Address {addr:x} already mapped")
addr = p.memory.map_anywhere(args.length,
name=memory_region_name,
kind=syscall_name)
p.memory.write(addr, data)
return addr
def alloc(self, size: int, name: str = None, align: int = 0x4) -> int:
"""
Allocates memory to the heap. These are rounded up to the size
of the alignment.
Args:
size: Number of bytes to allocate.
name: Used to keep track of what information was allocated.
Used for debugging
align: Ensures that the memory allocated is a multiple of
this value. Defaults to 4.
Returns:
Address of the new heap boundary
"""
self.logger.debug(f"Allocating {size:x} bytes named {name}")
ret = self.current_offset
requested_size = util.align(size, alignment=align)
if (self.current_offset + requested_size >=
self.heap_start + self.heap_max_size):
self.logger.error(
"Ran out of heap memory . Try increasing max heap size.")
return ret
self.current_offset += requested_size
# TODO(kvalakuzhy): It would be nice if this could be moved into
# a heap tracking class.
self.heap_objects.add(_HeapObjInfo(ret, size, name=name))
return ret
def map_file_anywhere(
self,
filename: str,
offset: int = 0,
size: int = 0,
preferred_address: int = None,
min_addr: int = 0x1000,
max_addr: int = 0xFFFFFFFFFFFFFFFF,
alignment: int = 0x1000,
top_down: bool = False,
prot: int = ProtType.RWX,
shared: bool = False,
) -> int:
"""
Maps a region of memory with requested size, within the
addresses specified. The size and start address will respect the
alignment.
Args:
filename: Name of the file to memory map
offset: Page-aligned offset of file to start mapping
size: # of bytes to map. This will be rounded up to the
nearest page.
preferred_address: If the specified address is available,
it will be used for the mapping.
min_addr: The lowest address that could be mapped.
max_addr: The highest address that could be mapped.
alignment: Ensures the size and start address are multiples
of this. Must be a multiple of 0x1000. Default 0x1000.
top_down: If True, the region will be mapped to the
highest available address instead of the lowest.
prot: RWX permissions of the mapped region. Defaults to
granting all permissions.
shared: if True, region is shared with subprocesses.
Returns:
Start address of mapped region.
"""
if size == 0:
with open(filename, "rb") as f:
size = os.fstat(f.fileno()).st_size
size = util.align(size)
address = self.find_free_space(
size,
preferred_address=preferred_address,
min_addr=min_addr,
max_addr=max_addr,
alignment=alignment,
top_down=top_down,
)
if address is None:
raise OutOfMemoryException()
self.map_file(
address,
filename,
offset=offset,
size=size,
prot=prot,
shared=shared,
)
return address
def protect(self, address: int, size: int, prot: int) -> None:
"""
Sets memory permissions on the specified memory region. Respects
alignment of 0x1000.
Args:
address: Address of memory region to modify permissions.
Rounds down to nearest 0x1000.
size: Size of region to protect. Rounds up to nearest
0x1000.
prot: Desired RWX permissions.
TODO:
This does not correspond to Sections at the moment.
"""
if self.disableNX:
prot = prot | ProtType.EXEC
aligned_address = address & 0xFFFFF000 # Address needs to align with
aligned_size = util.align((address & 0xFFF) + size)
try:
self.emu.mem_protect(aligned_address, aligned_size, prot)
self.logger.debug(
"Protected region 0x%x + 0x%x, Prot: %x",
aligned_address,
aligned_size,
prot,
)
except Exception as e:
self.logger.error(f"Error trying to protect region "
f"0x{aligned_address:x} + 0x{aligned_size:x}, "
f"Prot: {prot:x}: {e}")
def _load_module(self, elf, module_name):
module_path, normalized_module_name = self._get_module_name(
module_name)
data = bytearray(elf.Data)
base = self.memory._alloc_at(
"",
"main",
basename(normalized_module_name),
elf.ImageBase,
elf.VirtualSize,
)
self.memory.write(base, bytes(data))
# Set proper permissions for each section of the module
for s in elf.Sections:
try:
self.memory.protect(
s.Address,
align(s.VirtualSize, s.Alignment),
s.Permissions,
# s.Name,
# "main",
# module_name=basename(module_path),
)
except Exception:
raise ZelosLoadException(
f"Bad section {hex(s.Address)} {hex(s.VirtualSize)}")
return base
def __init__(self, memory, gdt_base=0x80000000, size=0x1000):
self.emu = memory.emu
memory.map(gdt_base, align(size), prot=0x3)
self.emu.set_reg("gdtr", (0, gdt_base, size, 0x0))
self.gdt_base = gdt_base
self._init_gdt()
def sys_getdents64(sm, p):
global run_once
if run_once is not None:
return 0
args = sm.get_args([
("unsigned int", "fd"),
("struct linux_dirent64 *", "dirp"),
("unsigned int", "count"),
])
# struct linux_dirent64 {
# ino64_t d_ino; /* 64-bit inode number */
# off64_t d_off; /* 64-bit offset to next struct */
# unsigned short d_reclen; /* Size of this dirent */
# unsigned char d_type; /* File type */
# char d_name[]; /* Filename (null-terminated) */
# };
p.memory.write_int(args.dirp + 0x0, 56, sz=8)
p.memory.write_int(args.dirp + 0x8, 0x0, sz=8)
p.memory.write_int(args.dirp + 0x12, 6, sz=1)
s_len = p.memory.write_string(args.dirp + 0x13, "FolderContents")
struct_size = align(0x13 + s_len, 4)
# val = bytes([0xb + s_len, 0xb + s_len])
# from zelos.util import p16
# val2 = p16(0x13+s_len +0x100 )
# p.memory.write(args.dirp + 0x10, bytes([0x30]))
p.memory.write_int(args.dirp + 0x10, struct_size, sz=2)
run_once = 1
return struct_size
def _find_free_space(self,
size,
min_addr=0,
max_addr=MAX_UINT64,
alignment=0x10000):
"""
Finds a region of memory that is free, larger than 'size' arg,
and aligned.
"""
sections = list(self.memory_info.values())
for i in range(0, len(sections)):
addr = util.align(sections[i].address + sections[i].size,
alignment=alignment)
# Enable allocating memory in the middle of a gap when the
# min requested address falls in the middle of a gap
if addr < min_addr:
addr = min_addr
# Cap the gap's max address by accounting for the next
# section's start address, requested max address, and the
# max possible address
max_gap_addr = (self.max_addr if i == len(sections) -
1 else sections[i + 1].address)
max_gap_addr = min(max_gap_addr, max_addr)
# Ensure the end address is less than the max and the start
# address is free
if addr + size < max_gap_addr and self._is_free(addr):
return addr
raise OutOfMemoryException()
def hook_first_read(self, region_addr, hook):
region = self.get_region(region_addr)
size = self.get_size(region_addr)
perms = self.get_perms(region_addr)
if region is None or size is None or perms is None:
return False
addr = region.address
try:
self.emu.mem_protect(addr, util.align(size), ProtType.NONE)
except Exception:
self.logger.exception(
"Error trying to protect portion 0x%x + 0x%x, Prot: %x",
addr,
util.align(size),
ProtType.NONE,
)
self.mem_hooks[addr] = _MemHook(addr, size, perms, hook)
return True
def _hook_read_prot(self, uc, access, address, size, value, user_data):
region = self.get_region(address)
addr = region.address if region is not None else None
if addr not in self.mem_hooks:
return False
mem_hook = self.mem_hooks[addr]
self.emu.mem_protect(mem_hook.addr, util.align(mem_hook.size),
mem_hook.orig_perms)
del self.mem_hooks[addr]
return mem_hook.hook(uc, access, address, size, value, user_data)
def copy_section(self, section: Section, other_memory: "Memory") -> None:
"""
Copies a section from this instance of memory into another
instance of memory.
Args:
section: The section to copy. Must correspond to a section
within this memory object.
other_memory: An instance of memory to copy the specified
section to.
"""
start = section.address
size = section.size
end = start + size
# We have the beginning mapped for special addresses
if start == 0:
return
# Some sections are added to differentiate different sections in
# the binary. These are typically not aligned. If they are,
# should only be an extra copy.
if start != util.align(start) or end != util.align(end):
return
self.logger.spam(f"Copying {start:x}-{end:x}")
if section.ptr is None:
data = other_memory.read(start, size)
self.map(start, size)
self.write(start, bytes(data))
else:
self.map(start, size, ptr=section.ptr)
self._new_section(
section.address,
section.size,
name=section.name,
kind=section.kind,
module_name=section.module_name,
ptr=section.ptr,
)
def test_align(self):
self.assertEqual(0x1000, util.align(0x1000))
self.assertEqual(0x2000, util.align(0x1001))
self.assertEqual(0x1000, util.align(1))
self.assertEqual(0x12000, util.align(0x11002))
self.assertEqual(0x14, util.align(0x11, alignment=0x4))
self.assertEqual(0x10, util.align(0xF, alignment=0x4))
def find_free_space(
self,
size,
preferred_address=None,
min_addr=0x1000,
max_addr=MAX_UINT32,
alignment=0x10000,
top_down=False,
):
"""
Returns the start address of the next region between start and
end that allows for memory of the given size to be mapped.
"""
if preferred_address is not None and not self._has_overlap(
preferred_address, size):
return preferred_address
regions = self.get_regions()
# Check if space before first region is free
min_addr = util.align(min_addr, alignment=alignment)
if len(regions) == 0 or min_addr + size <= regions[0].address:
return min_addr
# Check if space between regions is free
for i in range(len(regions) - 1):
gap_begin = util.align(max(regions[i].end, min_addr),
alignment=alignment)
gap_end = min(min(max_addr, gap_begin + size),
regions[i + 1].start)
gap_size = gap_end - gap_begin
if gap_size >= size:
return gap_begin
# Check if space after last region is free
gap_begin = util.align(max(regions[-1].end, min_addr),
alignment=alignment)
gap_end = max_addr
gap_size = gap_end - gap_begin
if gap_size >= size:
return gap_begin
return None
def _alloc_at(
self,
name,
kind,
module_name,
requested_addr,
size,
min_addr=0x60000000,
max_addr=0x90000000,
prot=ProtType.RWX,
ptr=None,
):
# if requested_addr < min_addr:
# requested_addr = min_addr
if requested_addr > max_addr:
requested_addr = min_addr
size = util.align(size)
relocated_addr = 0
if self._has_overlap(requested_addr, size):
relocated_addr = self._get_next_gap(size, min_addr, max_addr)
self.logger.debug("[Loader] Relocating Overlapping Region from "
"0x{0:08x} to 0x{1:08x}".format(
requested_addr, relocated_addr))
try:
self.map(
relocated_addr,
size,
name,
kind,
module_name=module_name,
prot=prot,
ptr=ptr,
)
return relocated_addr
except Exception:
self.logger.exception("Couldn't relocate properly")
exit()
else:
self.map(
requested_addr,
size,
name,
kind,
module_name=module_name,
prot=prot,
ptr=ptr,
)
return requested_addr
def _load_state(self, data):
for meminfo, mem in data:
self.logger.debug("Loading: ", hex(meminfo.address),
hex(meminfo.size), meminfo)
mem = bytes(mem)
try:
self.emu.mem_write(meminfo.address, mem)
except Exception:
self.map(
meminfo.address,
util.align(meminfo.size),
meminfo.name,
meminfo.kind,
)
self.emu.mem_write(meminfo.address, mem)
def sys_getdents(sm, p):
args = sm.get_args([
("unsigned int", "fd"),
("struct linux_dirent *", "dirp"),
("unsigned int", "count"),
])
handle = sm.z.handles.get(args.fd)
if handle is None:
return -1
folder_contents = handle.data.get("dents", None)
if folder_contents is None:
# Get the dents and run this function
folder_contents = sm.z.files.list_dir(handle.Name)
if len(folder_contents) == 0:
handle.data["dents"] = folder_contents
return 0
prev_struct_start = None
struct_start = args.dirp
total_bytes_written = 0
while len(folder_contents) > 0:
full_name = os.path.join(handle.Name, folder_contents[-1])
bytes_written = _write_dirent_x86_64(
sm,
p,
full_name,
folder_contents[-1],
struct_start,
prev_struct_start,
args.dirp + args.count,
)
if bytes_written == 0:
break
else:
folder_contents.pop()
total_bytes_written += bytes_written
prev_struct_start = struct_start
struct_start = align(struct_start + bytes_written, alignment=0x4)
handle.data["dents"] = folder_contents
return total_bytes_written
def mem_map_file(
self,
address: int,
filename: str,
offset: int = 0,
size: int = 0,
prot: int = ProtType.RW,
shared: bool = False,
):
if address % 0x1000 != 0:
raise ValueError("invalid argument: address not aligned")
if offset % 0x1000 != 0:
raise ValueError("invalid argument: offset not aligned")
with open(filename, "rb") as f:
basename = os.path.basename(filename)
file_map = mmap.mmap(f.fileno(),
length=0,
offset=offset,
access=mmap.ACCESS_COPY)
ptr = ctypes.POINTER(ctypes.c_void_p)(
ctypes.c_void_p.from_buffer(file_map))
if size == 0:
size = os.fstat(f.fileno()).st_size
size = align(size)
if self._mem_area_overlaps(address, size):
raise ValueError("invalid argument: {address, size} overlaps")
mr = MemoryRegion(
self,
address,
size,
prot,
basename,
"mapped",
basename,
shared=shared,
host_address=ctypes.addressof(ptr.contents),
managed_object=file_map,
)
self._mem_map_region(mr)
return
raise ValueError("invalid argument: filename")
def _load_module(self, elf, module_name):
module_path, normalized_module_name = self._get_module_name(
module_name)
data = bytearray(elf.Data)
base = self.memory.map_anywhere(
elf.VirtualSize,
preferred_address=elf.ImageBase,
name="",
kind="main",
module_name=basename(normalized_module_name),
)
self.memory.write(base, bytes(data))
# Set proper permissions for each section of the module
for s in elf.Sections:
try:
self.memory.protect(s.Address, align(s.VirtualSize,
s.Alignment),
s.Permissions)
except Exception:
raise ZelosLoadException(
f"Bad section {hex(s.Address)} {hex(s.VirtualSize)}")
return base
def _get_next_gap(self, size, start, end):
"""
Returns the start address of the next region between start and
end that allows for memory of the given size to be mapped.
"""
min_addr_so_far = start
for region in sorted(list(self.emu.mem_regions()), key=lambda x: x[0]):
region_begin = region[0]
region_end = region[1]
if region_begin >= end or region_end < start:
continue
gap = region_begin - min_addr_so_far
if gap < size:
min_addr_so_far = util.align(region_end)
continue
return min_addr_so_far
# Check to see there is a gap after the last region
gap = end - min_addr_so_far
if gap < size:
self.logger.error("No gap of size %x between %x and %x" %
(size, start, end))
return min_addr_so_far
def __init__(
self,
emu,
address: int,
size: int,
prot: int,
name: str,
kind: str,
module_name: str,
shared: bool = False,
reserve: bool = False,
host_address: int = None,
managed_object: any = None,
):
if address % 0x1000 != 0:
raise ValueError("invalid argument: address not aligned")
if size <= 0:
raise ValueError("invalid argument: size invalid")
size = align(size)
self.emu = emu
self.address = address
self.size = size
self.prot = prot
self.name = name
self.kind = kind
self.module_name = module_name
self.reserved = reserve
self.shared = shared
if host_address is None:
self._managed_object = ctypes.create_string_buffer(size)
host_pointer = ctypes.cast(self._managed_object,
ctypes.POINTER(ctypes.c_char))
self.host_address = ctypes.addressof(host_pointer.contents)
else:
self.host_address = host_address
self._managed_object = managed_object
self.host_data = (ctypes.c_char * size).from_address(self.host_address)
def map_anywhere(
self,
size: int,
name: str = "",
kind: str = "",
min_addr: int = 0,
max_addr: int = 0xFFFFFFFFFFFFFFFF,
alignment: int = 0x1000,
prot: int = ProtType.RWX,
) -> int:
"""
Maps a region of memory with requested size, within the
addresses specified. The size and start address will respect the
alignment.
Args:
size: # of bytes to map. This will be rounded up to match
the alignment.
name: String used to identify mapped region. Used for
debugging.
kind: String used to identify the purpose of the mapped
region. Used for debugging.
min_addr: The lowest address that could be mapped.
max_addr: The highest address that could be mapped.
alignment: Ensures the size and start address are multiples
of this. Must be a multiple of 0x1000. Default 0x1000.
prot: RWX permissions of the mapped region. Defaults to
granting all permissions.
Returns:
Start address of mapped region.
"""
address = self._find_free_space(size,
min_addr=min_addr,
max_addr=max_addr,
alignment=alignment)
self.map(address, util.align(size), name, kind)
return address
def _write_dirent_x86_64(sm, p, full_name, basename, struct_start,
prev_struct_start, max_addr):
struct_len = align(len(basename) + 2 + 0x12, 4)
if struct_start + struct_len > max_addr:
return 0
library_path = sm.z.files.find_library(full_name)
if library_path is None or not path.exists(library_path):
return -1
statinfo = os.stat(library_path)
p.memory.write_uint64(struct_start, statinfo.st_ino)
# This will be overridden in the next call to this func
p.memory.write_uint64(struct_start + 0x8, 0) # next struct_start
p.memory.write_uint16(struct_start + 0x10, struct_len)
p.memory.write_string(struct_start + 0x12,
basename,
terminal_null_byte=True)
p.memory.write_uint8(struct_start + struct_len - 1, 8) # regular
if prev_struct_start is not None:
p.memory.write_uint64(prev_struct_start + 0x8, struct_start)
return struct_len
def parse(self, path, binary):
# Get symbols for the target dynamic binary before we replace
# it with the loader in the loading process. Keep in mind,
# these still need to be relocated.
# TODO: Need OS agnostic place to put this information
self._elf_dynamic_import_addrs = {
x.symbol.name: x.address
for x in binary.pltgot_relocations
}
self._target_entrypoint = binary.entrypoint
self._target_imagebase = binary.imagebase
interpreter = self._get_interpreter(binary)
if interpreter is not None:
# TODO: automatically do setup to run dynamic linux binaries
(path, binary) = self._setup_dynamic_binary(interpreter, binary)
self.Filepath = path
self.binary = binary
# Refer parsed binary and symbols for better logging
# @@NOTE binary.get_function_address on binary.symbols invokes
# a _lot_ of brk()
functions = {}
for symbol in binary.static_symbols:
if symbol.is_function:
text_sections = binary.get_section(".text")
text_va = text_sections.virtual_address
text_offset = text_sections.offset
text_base = text_va - text_offset
symbol_offset = symbol.value - text_base
if symbol_offset > 0:
functions[symbol.value] = symbol.name
self.exported_functions = functions
# Parse Architecture
machine = binary.header.machine_type
if machine == lief.ELF.ARCH.i386:
self.Architecture = "x86"
self.Mode = "32"
self.Bits = 32
elif machine == lief.ELF.ARCH.x86_64:
self.Architecture = "x86_64"
self.Mode = "64"
self.Bits = 64
elif machine == lief.ELF.ARCH.ARM:
self.Architecture = "arm"
self.Mode = "32"
self.Bits = 32
# When looking at other archs, this gives information about
# stack for arm:
# https://stackoverflow.com/questions/1802783/initial-state-of-program-registers-and-stack-on-linux-arm/6002815#6002815
elif machine == lief.ELF.ARCH.MIPS:
self.Architecture = "mips"
self.mode = "32"
self.bits = 32
else:
raise UnsupportedBinaryError(f"Unsupported arch {machine} for ELF")
if binary.is_pie:
raise UnsupportedBinaryError("Can't handle PIE binaries")
self.Data = [0] * binary.virtual_size
# TODO: More time should be invested here to figure out whether
# this is legit.
# lets arbitrarily load things at 0x0b000000
self.logger.debug(f"Binary's imagebase is {binary.imagebase:x}")
relocated_base = 0 if binary.imagebase != 0 else 0xB000000
base = relocated_base + binary.imagebase
self.base = base
# Only load segments that are the LOAD type.
segments_to_load = []
for s in binary.segments:
if s.type == lief.ELF.SEGMENT_TYPES.LOAD:
segments_to_load.append(s)
if len(segments_to_load) == 0:
raise UnsupportedBinaryError("No loadable segment")
for segment in segments_to_load:
virtual_offset = segment.virtual_address - binary.imagebase
self.Data[virtual_offset:virtual_offset +
len(segment.content)] = segment.content
self.logger.debug(
f"Load segment from {binary.imagebase + virtual_offset:x} to"
f" {binary.imagebase+virtual_offset+len(segment.content):x}")
for s in segment.sections:
section = Section()
section.Name = s.name
alignment = s.alignment
section.Size = util.align(s.size, alignment)
section.VirtualSize = util.align(s.size, alignment)
section.Address = relocated_base + s.virtual_address
section.Permissions = 7
section.Alignment = 0 if s.alignment < 2 else s.alignment
# print(s)
# print(dir(s))
self.Sections.append(section)
offset = section.Address - self.base
self.logger.verbose(
"Adding data for section %s at offset %x of size %x",
s.name,
offset,
len(s.content),
)
# Load the ELF header and the program/section headers.
ph_offset = binary.header.program_header_offset
ph_data_size = (binary.header.program_header_size *
binary.header.numberof_segments)
self.Data[:ph_offset +
ph_data_size] = binary.get_content_from_virtual_address(
binary.imagebase, ph_offset + ph_data_size)
self.set_tls_data(binary)
# Set Misc. Binary Attributes
self.Filename = basename(self.Filepath)
self.Shortname = splitext(self.Filename)[0]
self.ImageBase = base
self.EntryPoint = relocated_base + binary.entrypoint
self.VirtualSize = binary.virtual_size
self.HeaderAddress = base + binary.header.program_header_offset
self.HeaderSize = binary.header.program_header_size
self.NumberOfProgramHeaders = binary.header.numberof_segments
return
def map_anywhere(
self,
size: int,
preferred_address: int = None,
name: str = "",
kind: str = "",
module_name: str = "",
min_addr: int = 0x1000,
max_addr: int = 0xFFFFFFFFFFFFFFFF,
alignment: int = 0x1000,
top_down: bool = False,
prot: int = ProtType.RWX,
shared: bool = False,
) -> int:
"""
Maps a region of memory with requested size, within the
addresses specified. The size and start address will respect the
alignment.
Args:
size: # of bytes to map. This will be rounded up to match
the alignment.
preferred_address: If the specified address is available,
it will be used for the mapping.
name: String used to identify mapped region. Used for
debugging.
kind: String used to identify the purpose of the mapped
region. Used for debugging.
module_name: String used to identify the module that mapped
this region.
min_addr: The lowest address that could be mapped.
max_addr: The highest address that could be mapped.
alignment: Ensures the size and start address are multiples
of this. Must be a multiple of 0x1000. Default 0x1000.
top_down: If True, the region will be mapped to the
highest available address instead of the lowest.
prot: RWX permissions of the mapped region. Defaults to
granting all permissions.
shared: if True, region is shared with subprocesses.
Returns:
Start address of mapped region.
"""
address = self.find_free_space(
size,
preferred_address=preferred_address,
min_addr=min_addr,
max_addr=max_addr,
alignment=alignment,
top_down=top_down,
)
if address is None:
raise OutOfMemoryException()
self.map(
address,
util.align(size),
name=name,
kind=kind,
module_name=module_name,
prot=prot,
shared=shared,
)
return address
