Nice finding, Guiseppe. :) You're right that this may be unrelated to Igor's problem, but lines 811–813 look like a nice bait for JPEG images with malformed EXIF header[s] — values less than 8 will wrap around zero, leading to an attempt to skip unknown amount of data (QDataStream::skipRawData() takes an "int", but after subtraction 'offset' would be something not representable as a 32-bit signed integer and behavior of such conversions is not defined by the standard).
On 01/28/2015 12:18 AM, Giuseppe D'Angelo wrote:
> Il 27/01/2015 20:27, Igor Mironchik ha scritto:
>> I've looked at qjpeghandler.cpp and it is strangely that practically all
>> of my photos produced by my Android camera is corrupted. Do you know any
>> software that can give me information about exif in jpeg that I can be
>> sure that jpeg is corrupted? Thank you.
>
> Possibly exiftool or some any other image manipulation program.
>
> But also I wonder about the code around your backtrace:
>
>> 0 qt_message_fatal qlogging.cpp 1407 0x57ed3f21
>> 1 QMessageLogger::warning qlogging.cpp 396 0x57ed28bb
>> 2 QBuffer::seek qbuffer.cpp 374 0x5807b386
>> 3 QDataStream::skipRawData qdatastream.cpp 1169 0x5807dfbc
>> 4 getExifOrientation qjpeghandler.cpp 820 0x5ab66204
>
> =>
>
>> 795 quint32 offset;
>> ...
>> 811 stream >> offset;
>> 812 // we have already used 8 bytes of TIFF header
>> 813 offset -= 8;
>> 814
>> 815 // read IFD
>> 816 while (!stream.atEnd()) {
>> 817 quint16 numEntries;
>> 818
>> 819 // skip offset bytes to get the next IFD
>> 820 if (stream.skipRawData(offset) != (qint32)offset)
>> 821 return -1;
>
> Note in particular that "stream" reads an unsigned 32 bit int into
> offset, but then skipRawData silently converts to signed... (but it may
> be totally unrelated with the problem here, which perhaps results from
> bad EXIF parsing on Qt side)
>
> HTH,
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