python-pillow/backport-CVE-2020-35653.patch
renmingshuai 5c7a4a566e fix CVE-2020-35653
(cherry picked from commit 53731cfccae624ddd6b9b594b01574627fee1e8b)
2021-01-29 08:52:24 +08:00

41 lines
1.6 KiB
Diff

From 1eff62205ebe9d42a9417955d2955591be69c9bb 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.
commit 2f409261eb1228e166868f8f0b5da5cda52e55bf upstream
* Don't trust the image to specify a buffer size
Conflict:NA
Reference:https://github.com/python-pillow/Pillow/commit/2f409261eb1228e166868f8f0b5da5cda52e55bf
---
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 daa58b3..82aa3bb 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-2020-35655
+ stride = (self._size[0] * bits + 7) // 8
+ stride += stride % 2
+
bbox = (0, 0) + self.size
logger.debug("size: %sx%s", *self.size)
--
2.23.0