Serious issue using zlib
Posted: 2009-06-26T01:18:06-07:00
Hello,
I find a serious issue in the way of using zlib.
Look at blob.c / line 2373
If you look the gzio.c code, gzopen return an opaque structure which is not a FILE * (the structure is gz_stream internal to gzio.c)
This make ImageMagick crash several line after in the GetBlobSize function:
In this code, image->blob->file should be a FILE *, which is false in the zlib case.
It makes ImageMagick crashes on Windows.
Here is a file which is incorrectly reads it this help...
sports.wmz
I also think that a similar problem occurs with the BZipStream.
I didn't check it, but the code is the same and BZ2_bzopen also returns an opaque structure which is not a FILE * and should make crash :
I hope this help,
Manuel
I find a serious issue in the way of using zlib.
Look at blob.c / line 2373
Code: Select all
#if defined(MAGICKCORE_ZLIB_DELEGATE)
if (((strlen(filename) > 2) &&
(LocaleCompare(filename+strlen(filename)-2,".Z") == 0)) ||
((strlen(filename) > 3) &&
(LocaleCompare(filename+strlen(filename)-3,".gz") == 0)) ||
((strlen(filename) > 4) &&
(LocaleCompare(filename+strlen(filename)-4,".wmz") == 0)) ||
((strlen(filename) > 5) &&
(LocaleCompare(filename+strlen(filename)-5,".svgz") == 0)))
{
[b]image->blob->file=(FILE *) gzopen(filename,type);[/b] // This is an error!
if (image->blob->file != (FILE *) NULL)
image->blob->type=ZipStream;
}
else
#endifThis make ImageMagick crash several line after in the GetBlobSize function:
Code: Select all
case ZipStream:
{
#if defined(MAGICKCORE_ZLIB_DELEGATE)
if (fstat(fileno(image->blob->file),&image->blob->properties) == 0)
length=(MagickSizeType) image->blob->properties.st_size;
#endif
break;
}
It makes ImageMagick crashes on Windows.
Here is a file which is incorrectly reads it this help...
sports.wmz
I also think that a similar problem occurs with the BZipStream.
I didn't check it, but the code is the same and BZ2_bzopen also returns an opaque structure which is not a FILE * and should make crash :
Code: Select all
#if defined(MAGICKCORE_BZLIB_DELEGATE)
if (fstat(fileno(image->blob->file),&image->blob->properties) == 0)
length=(MagickSizeType) image->blob->properties.st_size;
#endif
Manuel