From 487f4136013d9fa3351b863e5f861463a1cbddcf Mon Sep 17 00:00:00 2001
From: Victor Rodriguez <victor.rodriguez.bahena@intel.com>
Date: Sat, 18 Aug 2018 13:54:55 +0000
Subject: [PATCH] Issue #9 - Fix null-pointer-dereference (CVE-2018-12648)
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The WEBP::GetLE32 function in
XMPFiles/source/FormatSupport/WEBP_Support.hpp in Exempi 2.4.5 has a
NULL pointer dereference.

https://bugs.freedesktop.org/show_bug.cgi?id=106981
https://gitlab.freedesktop.org/libopenraw/exempi/issues/9

Signed-off-by: Victor Rodriguez <victor.rodriguez.bahena@intel.com>
Signed-off-by: Hubert Figuière <hub@figuiere.net>
---
 XMPFiles/source/FormatSupport/WEBP_Support.cpp | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/XMPFiles/source/FormatSupport/WEBP_Support.cpp b/XMPFiles/source/FormatSupport/WEBP_Support.cpp
index ffaf220..4fe705b 100644
--- a/XMPFiles/source/FormatSupport/WEBP_Support.cpp
+++ b/XMPFiles/source/FormatSupport/WEBP_Support.cpp
@@ -160,9 +160,11 @@ bool VP8XChunk::xmp()
 }
 void VP8XChunk::xmp(bool hasXMP)
 {
-    XMP_Uns32 flags = GetLE32(&this->data[0]);
-    flags ^= (-hasXMP ^ flags) & (1 << XMP_FLAG_BIT);
-    PutLE32(&this->data[0], flags);
+    if (&this->data[0] != NULL) {
+        XMP_Uns32 flags = GetLE32(&this->data[0]);
+        flags ^= (-hasXMP ^ flags) & (1 << XMP_FLAG_BIT);
+        PutLE32(&this->data[0], flags);
+    }
 }
 
 Container::Container(WEBP_MetaHandler* handler) : Chunk(NULL, handler)
-- 
2.17.1