From: Dirk Lemstra <dirk@git.imagemagick.org>
Date: Tue, 16 Jan 2018 21:48:17 +0000 (+0100)
Subject: Added extra check to avoid use of uninitialized value.
X-Git-Tag: 7.0.7-22~48
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=8383c44b8f408de256e248a96c3c8192f5bece1f;p=imagemagick

Added extra check to avoid use of uninitialized value.
Credit to OSS-Fuzz
---

diff --git a/coders/viff.c b/coders/viff.c
index b79f2115a..d88a885d4 100644
--- a/coders/viff.c
+++ b/coders/viff.c
@@ -292,6 +292,8 @@ static Image *ReadVIFFImage(const ImageInfo *image_info,
       &viff_info.machine_dependency);
     (void) ReadBlob(image,sizeof(viff_info.reserve),viff_info.reserve);
     count=ReadBlob(image,512,(unsigned char *) viff_info.comment);
+    if (count != 512)
+      ThrowReaderException(CorruptImageError,"ImproperImageHeader");
     viff_info.comment[511]='\0';
     if (strlen(viff_info.comment) > 4)
       (void) SetImageProperty(image,"comment",viff_info.comment,exception);