Pillow/Tests/test_decompression_bomb.py
Eric Soroos 22e9bee4ef Fix DOS in PSDImagePlugin -- CVE-2021-28675
* PSDImagePlugin did not sanity check the number of input layers and
  vs the size of the data block, this could lead to a DOS on
  Image.open prior to Image.load.
* This issue dates to the PIL fork
2021-04-01 17:17:31 +03:00

108 lines
3.2 KiB
Python

import pytest
from PIL import Image
from .helper import hopper
TEST_FILE = "Tests/images/hopper.ppm"
ORIGINAL_LIMIT = Image.MAX_IMAGE_PIXELS
class TestDecompressionBomb:
@classmethod
def teardown_class(cls):
Image.MAX_IMAGE_PIXELS = ORIGINAL_LIMIT
def test_no_warning_small_file(self):
# Implicit assert: no warning.
# A warning would cause a failure.
with Image.open(TEST_FILE):
pass
def test_no_warning_no_limit(self):
# Arrange
# Turn limit off
Image.MAX_IMAGE_PIXELS = None
assert Image.MAX_IMAGE_PIXELS is None
# Act / Assert
# Implicit assert: no warning.
# A warning would cause a failure.
with Image.open(TEST_FILE):
pass
def test_warning(self):
# Set limit to trigger warning on the test file
Image.MAX_IMAGE_PIXELS = 128 * 128 - 1
assert Image.MAX_IMAGE_PIXELS == 128 * 128 - 1
def open():
with Image.open(TEST_FILE):
pass
pytest.warns(Image.DecompressionBombWarning, open)
def test_exception(self):
# Set limit to trigger exception on the test file
Image.MAX_IMAGE_PIXELS = 64 * 128 - 1
assert Image.MAX_IMAGE_PIXELS == 64 * 128 - 1
with pytest.raises(Image.DecompressionBombError):
with Image.open(TEST_FILE):
pass
@pytest.mark.xfail(reason="different exception")
def test_exception_ico(self):
with pytest.raises(Image.DecompressionBombError):
with Image.open("Tests/images/decompression_bomb.ico"):
pass
def test_exception_gif(self):
with pytest.raises(Image.DecompressionBombError):
with Image.open("Tests/images/decompression_bomb.gif"):
pass
def test_exception_bmp(self):
with pytest.raises(Image.DecompressionBombError):
with Image.open("Tests/images/bmp/b/reallybig.bmp"):
pass
class TestDecompressionCrop:
@classmethod
def setup_class(self):
width, height = 128, 128
Image.MAX_IMAGE_PIXELS = height * width * 4 - 1
@classmethod
def teardown_class(self):
Image.MAX_IMAGE_PIXELS = ORIGINAL_LIMIT
def testEnlargeCrop(self):
# Crops can extend the extents, therefore we should have the
# same decompression bomb warnings on them.
with hopper() as src:
box = (0, 0, src.width * 2, src.height * 2)
pytest.warns(Image.DecompressionBombWarning, src.crop, box)
def test_crop_decompression_checks(self):
im = Image.new("RGB", (100, 100))
good_values = ((-9999, -9999, -9990, -9990), (-999, -999, -990, -990))
warning_values = ((-160, -160, 99, 99), (160, 160, -99, -99))
error_values = ((-99909, -99990, 99999, 99999), (99909, 99990, -99999, -99999))
for value in good_values:
assert im.crop(value).size == (9, 9)
for value in warning_values:
pytest.warns(Image.DecompressionBombWarning, im.crop, value)
for value in error_values:
with pytest.raises(Image.DecompressionBombError):
im.crop(value)