python-pillow/SOURCES/CVE-2021-28675.patch
2021-11-09 09:46:11 +00:00

147 lines
4.3 KiB
Diff

From 7fe3dff241c11206616bf6229be898854ce0d066 Mon Sep 17 00:00:00 2001
From: Lumir Balhar <lbalhar@redhat.com>
Date: Mon, 14 Jun 2021 11:33:36 +0200
Subject: [PATCH] CVE-2021-28675
---
src/PIL/ImageFile.py | 12 ++++++++++--
src/PIL/PsdImagePlugin.py | 33 +++++++++++++++++++++++----------
2 files changed, 33 insertions(+), 12 deletions(-)
diff --git a/src/PIL/ImageFile.py b/src/PIL/ImageFile.py
index 1a3c4aa..2cef9ee 100644
--- a/src/PIL/ImageFile.py
+++ b/src/PIL/ImageFile.py
@@ -522,12 +522,18 @@ def _safe_read(fp, size):
:param fp: File handle. Must implement a <b>read</b> method.
:param size: Number of bytes to read.
- :returns: A string containing up to <i>size</i> bytes of data.
+ :returns: A string containing <i>size</i> bytes of data.
+
+ Raises an OSError if the file is truncated and the read can not be completed
+
"""
if size <= 0:
return b""
if size <= SAFEBLOCK:
- return fp.read(size)
+ data = fp.read(size)
+ if len(data) < size:
+ raise OSError("Truncated File Read")
+ return data
data = []
while size > 0:
block = fp.read(min(size, SAFEBLOCK))
@@ -535,6 +541,8 @@ def _safe_read(fp, size):
break
data.append(block)
size -= len(block)
+ if sum(len(d) for d in data) < size:
+ raise OSError("Truncated File Read")
return b"".join(data)
diff --git a/src/PIL/PsdImagePlugin.py b/src/PIL/PsdImagePlugin.py
index fe2a2ff..add9996 100644
--- a/src/PIL/PsdImagePlugin.py
+++ b/src/PIL/PsdImagePlugin.py
@@ -18,6 +18,8 @@
__version__ = "0.4"
+import io
+
from . import Image, ImageFile, ImagePalette
from ._binary import i8, i16be as i16, i32be as i32
@@ -114,7 +116,8 @@ class PsdImageFile(ImageFile.ImageFile):
end = self.fp.tell() + size
size = i32(read(4))
if size:
- self.layers = _layerinfo(self.fp)
+ _layer_data = io.BytesIO(ImageFile._safe_read(self.fp, size))
+ self.layers = _layerinfo(_layer_data, size)
self.fp.seek(end)
#
@@ -164,11 +167,20 @@ class PsdImageFile(ImageFile.ImageFile):
Image.Image.load(self)
-def _layerinfo(file):
+def _layerinfo(fp, ct_bytes):
# read layerinfo block
layers = []
- read = file.read
- for i in range(abs(i16(read(2)))):
+
+ def read(size):
+ return ImageFile._safe_read(fp, size)
+
+ ct = i16(read(2))
+
+ # sanity check
+ if ct_bytes < (abs(ct) * 20):
+ raise SyntaxError("Layer block too short for number of layers requested")
+
+ for i in range(abs(ct)):
# bounding box
y0 = i32(read(4))
@@ -179,7 +191,8 @@ def _layerinfo(file):
# image info
info = []
mode = []
- types = list(range(i16(read(2))))
+ ct_types = i16(read(2))
+ types = list(range(ct_types))
if len(types) > 4:
continue
@@ -212,7 +225,7 @@ def _layerinfo(file):
size = i32(read(4)) # length of the extra data field
combined = 0
if size:
- data_end = file.tell() + size
+ data_end = fp.tell() + size
length = i32(read(4))
if length:
@@ -220,12 +233,12 @@ def _layerinfo(file):
mask_x = i32(read(4))
mask_h = i32(read(4)) - mask_y
mask_w = i32(read(4)) - mask_x
- file.seek(length - 16, 1)
+ fp.seek(length - 16, 1)
combined += length + 4
length = i32(read(4))
if length:
- file.seek(length, 1)
+ fp.seek(length, 1)
combined += length + 4
length = i8(read(1))
@@ -235,7 +248,7 @@ def _layerinfo(file):
name = read(length).decode('latin-1', 'replace')
combined += length + 1
- file.seek(data_end)
+ fp.seek(data_end)
layers.append((name, mode, (x0, y0, x1, y1)))
# get tiles
@@ -243,7 +256,7 @@ def _layerinfo(file):
for name, mode, bbox in layers:
tile = []
for m in mode:
- t = _maketile(file, m, bbox, 1)
+ t = _maketile(fp, m, bbox, 1)
if t:
tile.extend(t)
layers[i] = name, mode, bbox, tile
--
2.31.1