nixpkgs/pkgs/development/libraries/expat/CVE-2015-1283-refix.patch
Robert Helgesson 34cf7934c3 expat: patch CVE-2015-1283 and CVE-2016-0718 (close #15561)
Note, CVE-2015-1283 is already patched in expat version 2.1.1 but, as
explained in the patch, the fix was insufficient.
2016-05-20 09:43:29 +02:00

38 lines
1.3 KiB
Diff

From 29a11774d8ebbafe8418b4a5ffb4cc1160b194a1 Mon Sep 17 00:00:00 2001
From: Pascal Cuoq <cuoq@trust-in-soft.com>
Date: Sun, 15 May 2016 09:05:46 +0200
Subject: [PATCH] Avoid relying on undefined behavior in CVE-2015-1283 fix. It
does not really work: https://godbolt.org/g/Zl8gdF
---
expat/lib/xmlparse.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/lib/xmlparse.c b/lib/xmlparse.c
index 13e080d..cdb12ef 100644
--- a/lib/xmlparse.c
+++ b/lib/xmlparse.c
@@ -1693,7 +1693,8 @@ XML_GetBuffer(XML_Parser parser, int len)
}
if (len > bufferLim - bufferEnd) {
- int neededSize = len + (int)(bufferEnd - bufferPtr);
+ /* Do not invoke signed arithmetic overflow: */
+ int neededSize = (int) ((unsigned)len + (unsigned)(bufferEnd - bufferPtr));
if (neededSize < 0) {
errorCode = XML_ERROR_NO_MEMORY;
return NULL;
@@ -1725,7 +1726,8 @@ XML_GetBuffer(XML_Parser parser, int len)
if (bufferSize == 0)
bufferSize = INIT_BUFFER_SIZE;
do {
- bufferSize *= 2;
+ /* Do not invoke signed arithmetic overflow: */
+ bufferSize = (int) (2U * (unsigned) bufferSize);
} while (bufferSize < neededSize && bufferSize > 0);
if (bufferSize <= 0) {
errorCode = XML_ERROR_NO_MEMORY;
--
2.8.2