python-pillow/SOURCES/CVE-2020-35653.patch
2021-11-09 09:46:11 +00:00

42 lines
1.4 KiB
Diff

From 7a0aea5806d57e0e7c5187fbc9c2937a16e0bca1 Mon Sep 17 00:00:00 2001
From: Eric Soroos <eric-github@soroos.net>
Date: Thu, 17 Dec 2020 00:17:53 +0100
Subject: [PATCH] Fix for CVE CVE-2020-35655 - Read Overflow in PCX Decoding.
* Don't trust the image to specify a buffer size
---
src/PIL/PcxImagePlugin.py | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/src/PIL/PcxImagePlugin.py b/src/PIL/PcxImagePlugin.py
index 564713a..17bbd18 100644
--- a/src/PIL/PcxImagePlugin.py
+++ b/src/PIL/PcxImagePlugin.py
@@ -63,9 +63,9 @@ class PcxImageFile(ImageFile.ImageFile):
version = i8(s[1])
bits = i8(s[3])
planes = i8(s[65])
- stride = i16(s, 66)
+ ignored_stride = i16(s, 66)
logger.debug("PCX version %s, bits %s, planes %s, stride %s",
- version, bits, planes, stride)
+ version, bits, planes, ignored_stride)
self.info["dpi"] = i16(s, 12), i16(s, 14)
@@ -102,6 +102,11 @@ class PcxImageFile(ImageFile.ImageFile):
self.mode = mode
self.size = bbox[2]-bbox[0], bbox[3]-bbox[1]
+ # don't trust the passed in stride. Calculate for ourselves.
+ # CVE-2020-35653
+ stride = (self.size[0] * bits + 7) // 8
+ stride += stride % 2
+
bbox = (0, 0) + self.size
logger.debug("size: %sx%s", *self.size)
--
2.29.2