Merge branch 'master' into core_tags

CHANGES.rst

@@ -2,6 +2,12 @@
 Changelog (Pillow)
 ==================
 
+8.3.0 (unreleased)
+------------------
+
+- Fixed reading uncompressed RGB data from DDS #5383
+  [radarhere]
+
 8.2.0 (2021-04-01)
 ------------------
 

Makefile

@@ -102,6 +102,13 @@ sdist:
 test:
 	pytest -qq
 
+.PHONY: valgrind
+valgrind:
+	python3 -c "import pytest_valgrind" || pip3 install pytest-valgrind
+	PYTHONMALLOC=malloc valgrind --suppressions=Tests/oss-fuzz/python.supp --leak-check=no \
+            --log-file=/tmp/valgrind-output \
+            python3 -m pytest --no-memcheck -vv --valgrind --valgrind-log=/tmp/valgrind-output
+
 .PHONY: readme
 readme:
 	python3 setup.py --long-description | markdown2 > .long-description.html && open .long-description.html

Tests/32bit_segfault_check.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 import sys
 

Tests/check_fli_oob.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from PIL import Image
 

Tests/check_imaging_leaks.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 import pytest
 
 from PIL import Image

Tests/check_jp2_overflow.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # Reproductions/tests for OOB read errors in FliDecode.c
 

Tests/conftest.py

@@ -13,6 +13,11 @@ def pytest_report_header(config):
 
 
 def pytest_configure(config):
+    config.addinivalue_line(
+        "markers",
+        "pil_noop_mark: A conditional mark where nothing special happens",
+    )
+
     # We're marking some tests to ignore valgrind errors and XFAIL them.
     # Ensure that the mark is defined
     # even in cases where pytest-valgrind isn't installed

Tests/createfontdatachunk.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 import base64
 import os
 

Tests/helper.py

@@ -173,6 +173,21 @@ def skip_unless_feature_version(feature, version_required, reason=None):
     return pytest.mark.skipif(version_available < version_required, reason=reason)
 
 
+def mark_if_feature_version(mark, feature, version_blacklist, reason=None):
+    if not features.check(feature):
+        return pytest.mark.pil_noop_mark()
+    if reason is None:
+        reason = f"{feature} is {version_blacklist}"
+    version_required = parse_version(version_blacklist)
+    version_available = parse_version(features.version(feature))
+    if (
+        version_available.major == version_required.major
+        and version_available.minor == version_required.minor
+    ):
+        return mark(reason=reason)
+    return pytest.mark.pil_noop_mark()
+
+
 @pytest.mark.skipif(sys.platform.startswith("win32"), reason="Requires Unix or macOS")
 class PillowLeakTestCase:
     # requires unix/macOS

Tests/oss-fuzz/python.supp

@@ -0,0 +1,16 @@
+{
+   <py3_8_encode_current_locale>
+   Memcheck:Cond
+   ...
+   fun:encode_current_locale
+}
+
+
+{
+   <libtiff_zlib>
+   Memcheck:Cond
+   fun:inflate
+   fun:ZIPDecode
+   fun:_TIFFReadEncodedTileAndAllocBuffer
+   ...
+}

Tests/oss-fuzz/test_fuzzers.py

@@ -2,12 +2,19 @@ import subprocess
 import sys
 
 import fuzzers
+import packaging
 import pytest
 
-from PIL import Image
+from PIL import Image, features
 
 if sys.platform.startswith("win32"):
     pytest.skip("Fuzzer is linux only", allow_module_level=True)
+if features.check("libjpeg_turbo"):
+    version = packaging.version.parse(features.version("libjpeg_turbo"))
+    if version.major == 2 and version.minor == 0:
+        pytestmark = pytest.mark.valgrind_known_error(
+            reason="Known failing with libjpeg_turbo 2.0"
+        )
 
 
 @pytest.mark.parametrize(

Tests/test_file_dds.py

@@ -14,7 +14,8 @@ TEST_FILE_DX10_BC7 = "Tests/images/bc7-argb-8bpp_MipMaps-1.dds"
 TEST_FILE_DX10_BC7_UNORM_SRGB = "Tests/images/DXGI_FORMAT_BC7_UNORM_SRGB.dds"
 TEST_FILE_DX10_R8G8B8A8 = "Tests/images/argb-32bpp_MipMaps-1.dds"
 TEST_FILE_DX10_R8G8B8A8_UNORM_SRGB = "Tests/images/DXGI_FORMAT_R8G8B8A8_UNORM_SRGB.dds"
-TEST_FILE_UNCOMPRESSED_RGB = "Tests/images/uncompressed_rgb.dds"
+TEST_FILE_UNCOMPRESSED_RGB = "Tests/images/hopper.dds"
+TEST_FILE_UNCOMPRESSED_RGB_WITH_ALPHA = "Tests/images/uncompressed_rgb.dds"
 
 
 def test_sanity_dxt1():
@@ -124,15 +125,22 @@ def test_unimplemented_dxgi_format():
 def test_uncompressed_rgb():
     """Check uncompressed RGB images can be opened"""
 
+    # convert -format dds -define dds:compression=none hopper.jpg hopper.dds
     with Image.open(TEST_FILE_UNCOMPRESSED_RGB) as im:
-        im.load()
+        assert im.format == "DDS"
+        assert im.mode == "RGB"
+        assert im.size == (128, 128)
 
+        assert_image_equal_tofile(im, "Tests/images/hopper.png")
+
+    # Test image with alpha
+    with Image.open(TEST_FILE_UNCOMPRESSED_RGB_WITH_ALPHA) as im:
         assert im.format == "DDS"
         assert im.mode == "RGBA"
         assert im.size == (800, 600)
 
         assert_image_equal_tofile(
-            im, TEST_FILE_UNCOMPRESSED_RGB.replace(".dds", ".png")
+            im, TEST_FILE_UNCOMPRESSED_RGB_WITH_ALPHA.replace(".dds", ".png")
         )
 
 

Tests/test_file_eps.py

@@ -8,6 +8,7 @@ from .helper import (
     assert_image_similar,
     assert_image_similar_tofile,
     hopper,
+    mark_if_feature_version,
     skip_unless_feature,
 )
 
@@ -64,7 +65,9 @@ def test_invalid_file():
         EpsImagePlugin.EpsImageFile(invalid_file)
 
 
-@pytest.mark.valgrind_known_error(reason="Known Failing")
+@mark_if_feature_version(
+    pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+)
 @pytest.mark.skipif(not HAS_GHOSTSCRIPT, reason="Ghostscript not available")
 def test_cmyk():
     with Image.open("Tests/images/pil_sample_cmyk.eps") as cmyk_image:

Tests/test_file_jpeg.py

@@ -24,6 +24,7 @@ from .helper import (
     djpeg_available,
     hopper,
     is_win32,
+    mark_if_feature_version,
     skip_unless_feature,
 )
 
@@ -116,7 +117,9 @@ class TestFileJpeg:
         assert test(100, 200) == (100, 200)
         assert test(0) is None  # square pixels
 
-    @pytest.mark.valgrind_known_error(reason="Known Failing")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_icc(self, tmp_path):
         # Test ICC support
         with Image.open("Tests/images/rgb.jpg") as im1:
@@ -156,7 +159,9 @@ class TestFileJpeg:
         test(ImageFile.MAXBLOCK + 1)  # full buffer block plus one byte
         test(ImageFile.MAXBLOCK * 4 + 3)  # large block
 
-    @pytest.mark.valgrind_known_error(reason="Known Failing")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_large_icc_meta(self, tmp_path):
         # https://github.com/python-pillow/Pillow/issues/148
         # Sometimes the meta data on the icc_profile block is bigger than
@@ -423,7 +428,9 @@ class TestFileJpeg:
         with Image.open(filename):
             pass
 
-    @pytest.mark.valgrind_known_error(reason="Known Failing")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_truncated_jpeg_should_read_all_the_data(self):
         filename = "Tests/images/truncated_jpeg.jpg"
         ImageFile.LOAD_TRUNCATED_IMAGES = True
@@ -442,7 +449,9 @@ class TestFileJpeg:
             with pytest.raises(OSError):
                 im.load()
 
-    @pytest.mark.valgrind_known_error(reason="Known Failing")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_qtables(self, tmp_path):
         def _n_qtables_helper(n, test_file):
             with Image.open(test_file) as im:
@@ -726,7 +735,9 @@ class TestFileJpeg:
             # OSError for unidentified image.
             assert im.info.get("dpi") == (72, 72)
 
-    @pytest.mark.valgrind_known_error(reason="Known Failing")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_exif_x_resolution(self, tmp_path):
         with Image.open("Tests/images/flower.jpg") as im:
             exif = im.getexif()
@@ -757,7 +768,9 @@ class TestFileJpeg:
             # Act / Assert
             assert im._getexif()[306] == "2017:03:13 23:03:09"
 
-    @pytest.mark.valgrind_known_error(reason="Backtrace in Python Core")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_photoshop(self):
         with Image.open("Tests/images/photoshop-200dpi.jpg") as im:
             assert im.info["photoshop"][0x03ED] == {

Tests/test_file_libtiff.py

@@ -17,6 +17,7 @@ from .helper import (
     assert_image_similar,
     assert_image_similar_tofile,
     hopper,
+    mark_if_feature_version,
     skip_unless_feature,
 )
 
@@ -822,13 +823,17 @@ class TestFileLibTiff(LibTiffTestCase):
         with Image.open(infile) as im:
             assert_image_similar_tofile(im, "Tests/images/pil_sample_cmyk.jpg", 0.5)
 
-    @pytest.mark.valgrind_known_error(reason="Known Failing")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_strip_ycbcr_jpeg_2x2_sampling(self):
         infile = "Tests/images/tiff_strip_ycbcr_jpeg_2x2_sampling.tif"
         with Image.open(infile) as im:
             assert_image_similar_tofile(im, "Tests/images/flower.jpg", 0.5)
 
-    @pytest.mark.valgrind_known_error(reason="Known Failing")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_strip_ycbcr_jpeg_1x1_sampling(self):
         infile = "Tests/images/tiff_strip_ycbcr_jpeg_1x1_sampling.tif"
         with Image.open(infile) as im:
@@ -839,13 +844,17 @@ class TestFileLibTiff(LibTiffTestCase):
         with Image.open(infile) as im:
             assert_image_similar_tofile(im, "Tests/images/pil_sample_cmyk.jpg", 0.5)
 
-    @pytest.mark.valgrind_known_error(reason="Known Failing")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_tiled_ycbcr_jpeg_1x1_sampling(self):
         infile = "Tests/images/tiff_tiled_ycbcr_jpeg_1x1_sampling.tif"
         with Image.open(infile) as im:
             assert_image_equal_tofile(im, "Tests/images/flower2.jpg")
 
-    @pytest.mark.valgrind_known_error(reason="Known Failing")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_tiled_ycbcr_jpeg_2x2_sampling(self):
         infile = "Tests/images/tiff_tiled_ycbcr_jpeg_2x2_sampling.tif"
         with Image.open(infile) as im:

Tests/test_file_pdf.py

@@ -8,7 +8,7 @@ import pytest
 
 from PIL import Image, PdfParser
 
-from .helper import hopper
+from .helper import hopper, mark_if_feature_version
 
 
 def helper_save_as_pdf(tmp_path, mode, **kwargs):
@@ -85,7 +85,9 @@ def test_unsupported_mode(tmp_path):
         im.save(outfile)
 
 
-@pytest.mark.valgrind_known_error(reason="Known Failing")
+@mark_if_feature_version(
+    pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+)
 def test_save_all(tmp_path):
     # Single frame image
     helper_save_as_pdf(tmp_path, "RGB", save_all=True)
@@ -286,3 +288,13 @@ def test_pdf_append_to_bytesio():
     f = io.BytesIO(f.getvalue())
     im.save(f, format="PDF", append=True)
     assert len(f.getvalue()) > initial_size
+
+
+@pytest.mark.timeout(1)
+def test_redos():
+    malicious = b" trailer<<>>" + b"\n" * 3456
+
+    # This particular exception isn't relevant here.
+    # The important thing is it doesn't timeout, cause a ReDoS (CVE-2021-25292).
+    with pytest.raises(PdfParser.PdfFormatError):
+        PdfParser.PdfParser(buf=malicious)

Tests/test_file_png.py

@@ -13,6 +13,7 @@ from .helper import (
     hopper,
     is_big_endian,
     is_win32,
+    mark_if_feature_version,
     skip_unless_feature,
 )
 
@@ -679,7 +680,9 @@ class TestFilePng:
             exif = reloaded._getexif()
         assert exif[274] == 1
 
-    @pytest.mark.valgrind_known_error(reason="Known Failing")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_exif_from_jpg(self, tmp_path):
         with Image.open("Tests/images/pil_sample_rgb.jpg") as im:
             test_file = str(tmp_path / "temp.png")

Tests/test_file_webp_metadata.py

@@ -4,7 +4,7 @@ import pytest
 
 from PIL import Image
 
-from .helper import skip_unless_feature
+from .helper import mark_if_feature_version, skip_unless_feature
 
 pytestmark = [
     skip_unless_feature("webp"),
@@ -41,7 +41,9 @@ def test_read_exif_metadata_without_prefix():
         assert exif[305] == "Adobe Photoshop CS6 (Macintosh)"
 
 
-@pytest.mark.valgrind_known_error(reason="Known Failing")
+@mark_if_feature_version(
+    pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+)
 def test_write_exif_metadata():
     file_path = "Tests/images/flower.jpg"
     test_buffer = BytesIO()
@@ -74,7 +76,9 @@ def test_read_icc_profile():
             assert icc == expected_icc
 
 
-@pytest.mark.valgrind_known_error(reason="Known Failing")
+@mark_if_feature_version(
+    pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+)
 def test_write_icc_metadata():
     file_path = "Tests/images/flower2.jpg"
     test_buffer = BytesIO()
@@ -92,7 +96,9 @@ def test_write_icc_metadata():
         assert webp_icc_profile == expected_icc_profile, "Webp ICC didn't match"
 
 
-@pytest.mark.valgrind_known_error(reason="Known Failing")
+@mark_if_feature_version(
+    pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+)
 def test_read_no_exif():
     file_path = "Tests/images/flower.jpg"
     test_buffer = BytesIO()

Tests/test_image.py

@@ -16,6 +16,7 @@ from .helper import (
     assert_not_all_same,
     hopper,
     is_win32,
+    mark_if_feature_version,
     skip_unless_feature,
 )
 
@@ -662,7 +663,9 @@ class TestImage:
 
             assert not fp.closed
 
-    @pytest.mark.valgrind_known_error(reason="Known Failing")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_exif_jpeg(self, tmp_path):
         with Image.open("Tests/images/exif-72dpi-int.jpg") as im:  # Little endian
             exif = im.getexif()

Tests/test_image_resample.py

@@ -4,7 +4,12 @@ import pytest
 
 from PIL import Image, ImageDraw
 
-from .helper import assert_image_equal, assert_image_similar, hopper
+from .helper import (
+    assert_image_equal,
+    assert_image_similar,
+    hopper,
+    mark_if_feature_version,
+)
 
 
 class TestImagingResampleVulnerability:
@@ -455,7 +460,9 @@ class TestCoreResampleBox:
                 tiled.paste(tile, (x0, y0))
         return tiled
 
-    @pytest.mark.valgrind_known_error(reason="Known Failing")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_tiles(self):
         with Image.open("Tests/images/flower.jpg") as im:
             assert im.size == (480, 360)
@@ -466,7 +473,9 @@ class TestCoreResampleBox:
                 tiled = self.resize_tiled(im, dst_size, *tiles)
                 assert_image_similar(reference, tiled, 0.01)
 
-    @pytest.mark.valgrind_known_error(reason="Known Failing")
+    @mark_if_feature_version(
+        pytest.mark.valgrind_known_error, "libjpeg_turbo", "2.0", reason="Known Failing"
+    )
     def test_subsample(self):
         # This test shows advantages of the subpixel resizing
         # after supersampling (e.g. during JPEG decoding).

Tests/test_image_thumbnail.py

@@ -88,6 +88,7 @@ def test_no_resize():
         assert im.size == (64, 64)
 
 
+# valgrind test is failing with memory allocated in libjpeg
 @pytest.mark.valgrind_known_error(reason="Known Failing")
 def test_DCT_scaling_edges():
     # Make an image with red borders and size (N * 8) + 1 to cross DCT grid

Tests/test_imagedraw.py

@@ -722,6 +722,29 @@ def test_rounded_rectangle(xy):
     assert_image_equal_tofile(im, "Tests/images/imagedraw_rounded_rectangle.png")
 
 
+@pytest.mark.parametrize(
+    "xy, radius, type",
+    [
+        ((10, 20, 190, 180), 30.5, "given"),
+        ((10, 10, 181, 190), 90, "width"),
+        ((10, 20, 190, 181), 85, "height"),
+    ],
+)
+def test_rounded_rectangle_non_integer_radius(xy, radius, type):
+    # Arrange
+    im = Image.new("RGB", (200, 200))
+    draw = ImageDraw.Draw(im)
+
+    # Act
+    draw.rounded_rectangle(xy, radius, fill="red", outline="green", width=5)
+
+    # Assert
+    assert_image_equal_tofile(
+        im,
+        "Tests/images/imagedraw_rounded_rectangle_non_integer_radius_" + type + ".png",
+    )
+
+
 def test_rounded_rectangle_zero_radius():
     # Arrange
     im = Image.new("RGB", (W, H))

Tests/test_sgi_crash.py

@@ -1,4 +1,3 @@
-#!/usr/bin/env python
 import pytest
 
 from PIL import Image

docs/Guardfile

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 from livereload.compiler import shell
 from livereload.task import Task
 

selftest.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # minimal sanity check
 
 import sys

setup.py

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # > pyroma .
 # ------------------------------
 # Checking .

src/PIL/DdsImagePlugin.py

@@ -133,9 +133,11 @@ class DdsImageFile(ImageFile.ImageFile):
             rawmode = ""
             if bitcount == 32:
                 rawmode += masks[0xFF000000]
+            else:
+                self.mode = "RGB"
             rawmode += masks[0xFF0000] + masks[0xFF00] + masks[0xFF]
 
-            self.tile = [("raw", (0, 0) + self.size, 0, (rawmode, 0, 1))]
+            self.tile = [("raw", (0, 0) + self.size, 0, (rawmode[::-1], 0, 1))]
         else:
             data_start = header_size + 4
             n = 0

src/PIL/ImageDraw.py

@@ -282,6 +282,7 @@ class ImageDraw:
             # If the corners have no curve, that is a rectangle
             return self.rectangle(xy, fill, outline, width)
 
+        r = d // 2
         ink, fill = self._getink(outline, fill)
 
         def draw_corners(pieslice):
@@ -315,36 +316,28 @@ class ImageDraw:
             draw_corners(True)
 
             if full_x:
-                self.draw.draw_rectangle(
-                    (x0, y0 + d / 2 + 1, x1, y1 - d / 2 - 1), fill, 1
-                )
+                self.draw.draw_rectangle((x0, y0 + r + 1, x1, y1 - r - 1), fill, 1)
             else:
-                self.draw.draw_rectangle(
-                    (x0 + d / 2 + 1, y0, x1 - d / 2 - 1, y1), fill, 1
-                )
+                self.draw.draw_rectangle((x0 + r + 1, y0, x1 - r - 1, y1), fill, 1)
             if not full_x and not full_y:
-                self.draw.draw_rectangle(
-                    (x0, y0 + d / 2 + 1, x0 + d / 2, y1 - d / 2 - 1), fill, 1
-                )
-                self.draw.draw_rectangle(
-                    (x1 - d / 2, y0 + d / 2 + 1, x1, y1 - d / 2 - 1), fill, 1
-                )
+                self.draw.draw_rectangle((x0, y0 + r + 1, x0 + r, y1 - r - 1), fill, 1)
+                self.draw.draw_rectangle((x1 - r, y0 + r + 1, x1, y1 - r - 1), fill, 1)
         if ink is not None and ink != fill and width != 0:
             draw_corners(False)
 
             if not full_x:
                 self.draw.draw_rectangle(
-                    (x0 + d / 2 + 1, y0, x1 - d / 2 - 1, y0 + width - 1), ink, 1
+                    (x0 + r + 1, y0, x1 - r - 1, y0 + width - 1), ink, 1
                 )
                 self.draw.draw_rectangle(
-                    (x0 + d / 2 + 1, y1 - width + 1, x1 - d / 2 - 1, y1), ink, 1
+                    (x0 + r + 1, y1 - width + 1, x1 - r - 1, y1), ink, 1
                 )
             if not full_y:
                 self.draw.draw_rectangle(
-                    (x0, y0 + d / 2 + 1, x0 + width - 1, y1 - d / 2 - 1), ink, 1
+                    (x0, y0 + r + 1, x0 + width - 1, y1 - r - 1), ink, 1
                 )
                 self.draw.draw_rectangle(
-                    (x1 - width + 1, y0 + d / 2 + 1, x1, y1 - d / 2 - 1), ink, 1
+                    (x1 - width + 1, y0 + r + 1, x1, y1 - r - 1), ink, 1
                 )
 
     def _multiline_check(self, text):

src/decode.c

@@ -199,7 +199,7 @@ _setimage(ImagingDecoderObject *decoder, PyObject *args) {
             state->bytes = (state->bits * state->xsize + 7) / 8;
         }
         /* malloc check ok, overflow checked above */
-        state->buffer = (UINT8 *)malloc(state->bytes);
+        state->buffer = (UINT8 *)calloc(1, state->bytes);
         if (!state->buffer) {
             return ImagingError_MemoryError();
         }

src/encode.c

@@ -264,7 +264,7 @@ _setimage(ImagingEncoderObject *encoder, PyObject *args) {
         }
         state->bytes = (state->bits * state->xsize + 7) / 8;
         /* malloc check ok, overflow checked above */
-        state->buffer = (UINT8 *)malloc(state->bytes);
+        state->buffer = (UINT8 *)calloc(1, state->bytes);
         if (!state->buffer) {
             return ImagingError_MemoryError();
         }

src/libImaging/Jpeg2KDecode.c

@@ -861,6 +861,10 @@ j2k_decode_entry(Imaging im, ImagingCodecState state) {
                 state->state = J2K_STATE_FAILED;
                 goto quick_exit;
             }
+            /* Undefined behavior, sometimes decode_tile_data doesn't
+               fill the buffer and we do things with it later, leading
+               to valgrind errors. */
+            memset(new, 0, tile_info.data_size);
             state->buffer = new;
             buffer_size = tile_info.data_size;
         }