def pwnarray(addr, new_length = 0x666, proc = none):
'''Modify the array's (ArrayObject) initlen, capacity and length in memory'''
global dbg_engine
if dbg_engine == 'pykd':
# modify the ArrayObject's initial length
dbg.execute('ed %x %x' % (addr + 0x4, new_length))
# modify the ArrayObject's capacity
dbg.execute('ed %x %x' % (addr + 0x8, new_length))
# modify the ArrayObject's length
dbg.execute('ed %x %x' % (addr + 0xc, new_length))
lines = dbg.execute('dd %x l?8' % (addr)).split('\n')
print('[shadow] ArrayObject at 0x%x:' % (addr))
for line in lines:
if line != '':
print('[shadow] %s' % (line))
elif dbg_engine == 'gdb':
# XXX: not implemented yet
pass
else: # lldb
# XXX: not implemented yet
pass
def pwnarray(addr, new_length=0x666, proc=none):
'''Modify the array's (ArrayObject) initlen, capacity and length in memory'''
global dbg_engine
if dbg_engine == 'pykd':
# modify the ArrayObject's initial length
dbg.execute('ed %x %x' % (addr + 0x4, new_length))
# modify the ArrayObject's capacity
dbg.execute('ed %x %x' % (addr + 0x8, new_length))
# modify the ArrayObject's length
dbg.execute('ed %x %x' % (addr + 0xc, new_length))
lines = dbg.execute('dd %x l?8' % (addr)).split('\n')
print('[shadow] ArrayObject at 0x%x:' % (addr))
for line in lines:
if line != '':
print('[shadow] %s' % (line))
elif dbg_engine == 'gdb':
# XXX: not implemented yet
pass
else: # lldb
# XXX: not implemented yet
pass
def pwnarray(addr, new_length=0x666, proc=none):
"""Modify the array's (ArrayObject) initlen, capacity and length in memory"""
global dbg_engine
if dbg_engine == "pykd":
# modify the ArrayObject's initial length
dbg.execute("ed %x %x" % (addr + 0x4, new_length))
# modify the ArrayObject's capacity
dbg.execute("ed %x %x" % (addr + 0x8, new_length))
# modify the ArrayObject's length
dbg.execute("ed %x %x" % (addr + 0xC, new_length))
lines = dbg.execute("dd %x l?8" % (addr)).split("\n")
print("[shadow] ArrayObject at 0x%x:" % (addr))
for line in lines:
if line != "":
print("[shadow] %s" % (line))
elif dbg_engine == "gdb":
# XXX: not implemented yet
pass
else: # lldb
# XXX: not implemented yet
pass
def show_filled_holes():
print("[shadow] searching for filled holes (SVGImageElement/ArrayObject specific)")
try:
out = dbg.execute(dbg.filled_holes_expr)
out_len = len(out)
if out_len != 0:
print(out)
except:
print("[shadow] arrangement pattern not found")
if out_len == 0:
print("[shadow] arrangement pattern not found")
def show_filled_holes():
print('[shadow] searching for filled holes (SVGImageElement/ArrayObject specific)')
try:
out = dbg.execute(dbg.filled_holes_expr)
out_len = len(out)
if out_len != 0:
print(out)
except:
print('[shadow] arrangement pattern not found')
if out_len == 0:
print('[shadow] arrangement pattern not found')
def parse_chunks():
global jeheap
global dbg_engine
# delete the chunks' list
jeheap.chunks[:] = []
try:
root = dbg.to_int(dbg.eval_expr(dbg.chunk_rtree_root_expr))
height = dbg.to_int(dbg.eval_expr(dbg.chunk_rtree_height_expr))
level2bits = []
for i in range(0, height):
expr = dbg.chunk_rtree_level2bits_expr % (i)
level2bits.append(dbg.to_int(dbg.eval_expr(expr)))
except:
print('[shadow] error: cannot parse chunk radix tree')
sys.exit()
# XXX: check if we're running on x86_64,
# not required for windbg/pykd (see the dp command)
if jeheap.DWORD_SIZE == 8:
if dbg_engine == 'gdb':
dw_fmt = 'g'
else: # lldb
dw_fmt = 'XXX'
else:
if dbg_engine == 'gdb':
dw_fmt = 'w'
else: # lldb
dw_fmt = 'XXX'
# parse the radix tree using a stack
stack = [(root, 0)]
while len(stack):
(node, node_height) = stack.pop()
child_cnt = 1 << level2bits[node_height]
if dbg_engine == 'gdb':
expr = dbg.chunk_radix_expr % (child_cnt, dw_fmt, node)
elif dbg_engine == 'pykd':
child_cnt = child_cnt / 6 # XXX: is this correct on 64-bits?
expr = dbg.chunk_radix_expr % (node, child_cnt)
else: # lldb
expr = ''
dump = dbg.execute(expr)
for line in dump.split('\n'):
line = line[line.find(dbg.address_separator) + \
len(dbg.address_separator):]
for address in line.split():
try:
address = int(address, 16)
except:
address = 0
if address != 0:
# leaf nodes hold pointers to actual values
if node_height == height - 1:
expr = dbg.chunk_arena_expr % address
try:
arena_addr = dbg.to_int(dbg.eval_expr(expr))
except:
arena_addr = 0
exists = false
if arena_addr in [i.addr for i in jeheap.arenas]:
exists = true
if exists:
jeheap.chunks.append(
jemalloc.arena_chunk(address, arena_addr))
else:
jeheap.chunks.append(jemalloc.arena_chunk(address))
# non-leaf nodes are inserted in the stack
else:
stack.append((address, node_height + 1))
def parse_all_runs(proc=none):
global jeheap
global dbg_engine
# number of pages a chunk occupies
chunk_npages = jeheap.chunk_size >> 12
# offset of bits in arena_chunk_map_t in double words
bitmap_offset = dbg.offsetof('arena_chunk_map_t',
'bits') / jeheap.DWORD_SIZE
# number of double words occupied by an arena_chunk_map_t
chunk_map_dwords = (bitmap_offset / jeheap.DWORD_SIZE) + 1
if jeheap.DWORD_SIZE == 8:
if dbg_engine == 'gdb':
dword_fmt = 'g'
else: # lldb
dw_fmt = 'XXX'
else:
if dbg_engine == 'gdb':
dword_fmt = 'w'
else: # lldb
dw_fmt = 'XXX'
# the 12 least significant bits of each bitmap entry hold
# various flags for the corresponding run
flags_mask = (1 << 12) - 1
# delete the heap's runs' array
jeheap.runs[:] = []
for chunk in jeheap.chunks:
if not chunk.arena_addr:
continue
try:
if dbg_engine == 'gdb':
# parse the whole map at once to avoid gdb's delays
expr = dbg.chunk_map_expr % \
(chunk_npages * chunk_map_dwords, dword_fmt, chunk.addr)
elif dbg_engine == 'pykd':
chunk_map_len = (chunk_npages * chunk_map_dwords) / 4
chunk_map_addr = dbg.to_int(
dbg.eval_expr(dbg.chunk_map_expr % (chunk.addr)))
expr = dbg.chunk_map_dump_expr % (chunk_map_addr,
chunk_map_len)
else: # lldb
expr = ''
except:
print('[shadow] error: cannot read bitmap from chunk 0x%08x' %
(chunk.addr))
sys.exit()
lines = (dbg.execute(expr)).split('\n')
dwords = []
i = 0
for line in lines:
dwords += [int(dw, 16) for dw in \
line[line.find(dbg.address_separator) + \
len(dbg.address_separator):].split()]
bitmap = [dwords[i] for i in range(int(bitmap_offset), \
int(len(dwords)), int(bitmap_offset + 1))]
# traverse the bitmap
for mapelm in bitmap:
flags = mapelm & flags_mask
# flags == 1 means the chunk is small and the rest of the bits
# hold the actual run address
if flags == 1:
addr = mapelm & ~flags_mask
size = dbg.get_page_size()
# flags = 3 indicates a large chunk; calculate the run's address
# directly from the map element index and extract the run's size
elif flags == 3:
addr = chunk.addr + i * dbg.get_page_size()
size = mapelm & ~flags_mask
# run is not allocated? skip it
else:
continue
if addr not in [r.start for r in jeheap.runs]:
new_run = parse_run(addr, proc)
if new_run == none:
pass
else:
jeheap.runs.append(copy.deepcopy(new_run))
def parse_run(run_addr, proc=none):
'''Given a run's address return a jemalloc.arena_run object'''
global jeheap
new_run = jemalloc.arena_run()
new_run.start = run_addr
try:
new_run.bin_addr = dbg.read_memory(new_run.start, jeheap.DWORD_SIZE,
proc)
if jeheap.STANDALONE == false:
new_run.size = dbg.read_memory(new_run.bin_addr + \
(6 * jeheap.DWORD_SIZE), jeheap.DWORD_SIZE, proc)
new_run.end = new_run.start + new_run.size
new_run.region_size = dbg.read_memory(new_run.bin_addr + \
(5 * jeheap.DWORD_SIZE), jeheap.DWORD_SIZE, proc)
new_run.total_regions = dbg.read_memory(new_run.bin_addr + \
(7 * jeheap.DWORD_SIZE), jemalloc.INT_SIZE, proc)
if new_run.total_regions > 10000 or new_run.total_regions <= 0:
return none
except:
# print('[shadow] error parsing the metadata of run 0x%08x' % (run_addr))
return none
# XXX: this isn't correct on jemalloc standalone *debug* variant
try:
new_run.free_regions = dbg.read_memory(new_run.start + \
jeheap.DWORD_SIZE + jemalloc.INT_SIZE, jemalloc.INT_SIZE, proc)
except:
# print('[shadow] error parsing the free regions of run 0x%08x' % (run_addr))
new_run.free_regions = 0
if new_run.free_regions < 0:
new_run.free_regions = 0
# delete the run's regions
new_run.regions[:] = []
# parse the run's regions
new_run.reg0_offset = dbg.read_memory(new_run.bin_addr + \
(9 * jeheap.DWORD_SIZE), jeheap.DWORD_SIZE, proc)
if new_run.reg0_offset > 10000 or new_run.reg0_offset <= 0:
return none
first_region_addr = reg0_addr = run_addr + new_run.reg0_offset
regs_mask_bits = (new_run.total_regions / 8) + 1
regs_mask_addr = 0
regs_mask_str = ''
if dbg_engine == 'gdb':
regs_mask_addr = dbg.to_int(dbg.execute(dbg.regs_mask_addr_expr % \
(run_addr)))
regs_mask_str = dbg.execute(dbg.regs_mask_addr_bits_expr % \
(regs_mask_bits, regs_mask_addr))
elif dbg_engine == 'pykd':
regs_mask_addr = dbg.to_int(dbg.eval_expr(dbg.regs_mask_addr_expr % \
(run_addr)))
regs_mask_str = dbg.execute(dbg.regs_mask_addr_bits_expr % \
(regs_mask_addr, regs_mask_bits))
else: # lldb
regs_mask_str = ''
regs_mask = ''
if dbg_engine == 'gdb':
for line in regs_mask_str.splitlines():
line = line[line.find(dbg.address_separator) + \
len(dbg.address_separator) : line.find('\n')]
line = line.replace('\n', '')
line = line.replace('\t', '')
line = line.replace(' ', '')
regs_mask += line
elif dbg_engine == 'pykd':
lines = regs_mask_str.splitlines()
lines = lines[2:]
for line in lines:
line = line[line.find(dbg.address_separator) + \
len(dbg.address_separator) : \
line.rfind(dbg.address_separator)]
line = line.replace('\n', '')
line = line.replace('\t', '')
line = line.replace(' ', '')
regs_mask += line
else: # lldb
regs_mask = ''
new_run.regs_mask = regs_mask
first_region = jemalloc.region(0, first_region_addr, \
int(new_run.regs_mask[0]))
try:
first_region.content_preview = hex(dbg.read_memory(first_region.addr, \
jemalloc.INT_SIZE, proc)).rstrip('L')
except:
print('[shadow] error reading the first dword of region 0x%08x' \
% (first_region.addr))
first_region.content_preview = ''
new_run.regions.append(first_region)
for i in range(1, new_run.total_regions):
try:
current_region = jemalloc.region(i, 0, int(new_run.regs_mask[i]))
except:
current_region = jemalloc.region(i, 0, 0)
current_region.addr = reg0_addr + (i * new_run.region_size)
try:
current_region.content_preview = \
hex(dbg.read_memory(current_region.addr, jemalloc.INT_SIZE, proc)).rstrip('L')
except:
current_region.content_preview = ''
new_run.regions.append(current_region)
return new_run
def parse_chunks():
global jeheap
global dbg_engine
# delete the chunks' list
jeheap.chunks[:] = []
try:
root = dbg.to_int(dbg.eval_expr(dbg.chunk_rtree_root_expr))
height = dbg.to_int(dbg.eval_expr(dbg.chunk_rtree_height_expr))
level2bits = []
for i in range(0, height):
expr = dbg.chunk_rtree_level2bits_expr % (i)
level2bits.append(dbg.to_int(dbg.eval_expr(expr)))
except:
print("[shadow] error: cannot parse chunk radix tree")
sys.exit()
# XXX: check if we're running on x86_64,
# not required for windbg/pykd (see the dp command)
if jeheap.DWORD_SIZE == 8:
if dbg_engine == "gdb":
dw_fmt = "g"
else: # lldb
dw_fmt = "XXX"
else:
if dbg_engine == "gdb":
dw_fmt = "w"
else: # lldb
dw_fmt = "XXX"
# parse the radix tree using a stack
stack = [(root, 0)]
while len(stack):
(node, node_height) = stack.pop()
child_cnt = 1 << level2bits[node_height]
if dbg_engine == "gdb":
expr = dbg.chunk_radix_expr % (child_cnt, dw_fmt, node)
elif dbg_engine == "pykd":
if dbg.get_arch() == "x86":
child_cnt = child_cnt / 6
expr = dbg.chunk_radix_expr % (node, child_cnt)
else: # lldb
expr = ""
dump = dbg.execute(expr)
for line in dump.split("\n"):
line = line[line.find(dbg.address_separator) + len(dbg.address_separator) :]
for address in line.split():
try:
address = int(address, 16)
except:
address = 0
if address != 0:
# leaf nodes hold pointers to actual values
if node_height == height - 1:
expr = dbg.chunk_arena_expr % address
try:
arena_addr = dbg.to_int(dbg.eval_expr(expr))
except:
arena_addr = 0
exists = false
if arena_addr in [i.addr for i in jeheap.arenas]:
exists = true
if exists:
jeheap.chunks.append(jemalloc.arena_chunk(address, arena_addr))
else:
jeheap.chunks.append(jemalloc.arena_chunk(address))
# non-leaf nodes are inserted in the stack
else:
stack.append((address, node_height + 1))
def parse_all_runs(proc=none):
global jeheap
global dbg_engine
# number of pages a chunk occupies
chunk_npages = jeheap.chunk_size >> 12
# offset of bits in arena_chunk_map_t in double words
if dbg_engine == "pykd":
# this really speeds up parsing
bitmap_offset = dbg.offsetof("mozglue!arena_chunk_map_t", "bits") / jeheap.DWORD_SIZE
else:
bitmap_offset = dbg.offsetof("arena_chunk_map_t", "bits") / jeheap.DWORD_SIZE
# number of double words occupied by an arena_chunk_map_t
chunk_map_dwords = (bitmap_offset / jeheap.DWORD_SIZE) + 1
if jeheap.DWORD_SIZE == 8:
if dbg_engine == "gdb":
dword_fmt = "g"
else: # lldb
dw_fmt = "XXX"
else:
if dbg_engine == "gdb":
dword_fmt = "w"
else: # lldb
dw_fmt = "XXX"
# the 12 least significant bits of each bitmap entry hold
# various flags for the corresponding run
flags_mask = (1 << 12) - 1
# delete the heap's runs' array
jeheap.runs[:] = []
for chunk in jeheap.chunks:
if not chunk.arena_addr:
continue
try:
if dbg_engine == "gdb":
# parse the whole map at once to avoid gdb's delays
expr = dbg.chunk_map_expr % (chunk_npages * chunk_map_dwords, dword_fmt, chunk.addr)
elif dbg_engine == "pykd":
chunk_map_len = (chunk_npages * chunk_map_dwords) / 4
chunk_map_addr = dbg.to_int(dbg.eval_expr(dbg.chunk_map_expr % (chunk.addr)))
expr = dbg.chunk_map_dump_expr % (chunk_map_addr, chunk_map_len)
else: # lldb
expr = ""
except:
print("[shadow] error: cannot read bitmap from chunk 0x%08x" % (chunk.addr))
sys.exit()
lines = (dbg.execute(expr)).split("\n")
dwords = []
i = 0
for line in lines:
dwords += [
int(dw, 16) for dw in line[line.find(dbg.address_separator) + len(dbg.address_separator) :].split()
]
bitmap = [dwords[i] for i in range(int(bitmap_offset), int(len(dwords)), int(bitmap_offset + 1))]
# traverse the bitmap
for mapelm in bitmap:
flags = mapelm & flags_mask
# flags == 1 means the chunk is small and the rest of the bits
# hold the actual run address
if flags == 1:
addr = mapelm & ~flags_mask
size = dbg.get_page_size()
# flags = 3 indicates a large chunk; calculate the run's address
# directly from the map element index and extract the run's size
elif flags == 3:
addr = chunk.addr + i * dbg.get_page_size()
size = mapelm & ~flags_mask
# run is not allocated? skip it
else:
continue
if addr not in [r.start for r in jeheap.runs]:
new_run = parse_run(addr, proc)
if new_run == none:
pass
else:
jeheap.runs.append(copy.deepcopy(new_run))
def parse_run(run_addr, proc=none):
"""Given a run's address return a jemalloc.arena_run object"""
global jeheap
new_run = jemalloc.arena_run()
new_run.start = run_addr
try:
new_run.bin_addr = dbg.read_memory(new_run.start, jeheap.DWORD_SIZE, proc)
if jeheap.STANDALONE == false:
new_run.size = dbg.read_memory(new_run.bin_addr + (6 * jeheap.DWORD_SIZE), jeheap.DWORD_SIZE, proc)
new_run.end = new_run.start + new_run.size
new_run.region_size = dbg.read_memory(new_run.bin_addr + (5 * jeheap.DWORD_SIZE), jeheap.DWORD_SIZE, proc)
new_run.total_regions = dbg.read_memory(new_run.bin_addr + (7 * jeheap.DWORD_SIZE), jemalloc.INT_SIZE, proc)
if new_run.total_regions > 10000 or new_run.total_regions <= 0:
return none
except:
# print('[shadow] error parsing the metadata of run 0x%08x' % (run_addr))
return none
# XXX: this isn't correct on jemalloc standalone *debug* variant
try:
new_run.free_regions = dbg.read_memory(
new_run.start + jeheap.DWORD_SIZE + jemalloc.INT_SIZE, jemalloc.INT_SIZE, proc
)
except:
# print('[shadow] error parsing the free regions of run 0x%08x' % (run_addr))
new_run.free_regions = 0
if new_run.free_regions < 0:
new_run.free_regions = 0
# delete the run's regions
new_run.regions[:] = []
# parse the run's regions
new_run.reg0_offset = dbg.read_memory(new_run.bin_addr + (9 * jeheap.DWORD_SIZE), jeheap.DWORD_SIZE, proc)
if new_run.reg0_offset > 10000 or new_run.reg0_offset <= 0:
return none
first_region_addr = reg0_addr = run_addr + new_run.reg0_offset
regs_mask_bits = (new_run.total_regions / 8) + 1
regs_mask_addr = 0
regs_mask_str = ""
if dbg_engine == "gdb":
regs_mask_addr = dbg.to_int(dbg.execute(dbg.regs_mask_addr_expr % (run_addr)))
regs_mask_str = dbg.execute(dbg.regs_mask_addr_bits_expr % (regs_mask_bits, regs_mask_addr))
elif dbg_engine == "pykd":
regs_mask_addr = dbg.to_int(dbg.eval_expr(dbg.regs_mask_addr_expr % (run_addr)))
regs_mask_str = dbg.execute(dbg.regs_mask_addr_bits_expr % (regs_mask_addr, regs_mask_bits))
else: # lldb
regs_mask_str = ""
regs_mask = ""
if dbg_engine == "gdb":
for line in regs_mask_str.splitlines():
line = line[line.find(dbg.address_separator) + len(dbg.address_separator) : line.find("\n")]
line = line.replace("\n", "")
line = line.replace("\t", "")
line = line.replace(" ", "")
regs_mask += line
elif dbg_engine == "pykd":
lines = regs_mask_str.splitlines()
lines = lines[2:]
for line in lines:
line = line[
line.find(dbg.address_separator) + len(dbg.address_separator) : line.rfind(dbg.address_separator)
]
line = line.replace("\n", "")
line = line.replace("\t", "")
line = line.replace(" ", "")
regs_mask += line
else: # lldb
regs_mask = ""
new_run.regs_mask = regs_mask
first_region = jemalloc.region(0, first_region_addr, int(new_run.regs_mask[0]))
try:
first_region.content_preview = hex(dbg.read_memory(first_region.addr, jemalloc.INT_SIZE, proc)).rstrip("L")
except:
print("[shadow] error reading the first dword of region 0x%08x" % (first_region.addr))
first_region.content_preview = ""
new_run.regions.append(first_region)
for i in range(1, new_run.total_regions):
try:
current_region = jemalloc.region(i, 0, int(new_run.regs_mask[i]))
except:
current_region = jemalloc.region(i, 0, 0)
current_region.addr = reg0_addr + (i * new_run.region_size)
try:
current_region.content_preview = hex(dbg.read_memory(current_region.addr, jemalloc.INT_SIZE, proc)).rstrip(
"L"
)
except:
current_region.content_preview = ""
new_run.regions.append(current_region)
return new_run
