2018.12.08 20:43 "[Tiff] Zlib inflate recovery action required?", by Bob Friesenhahn

I have a TIFF pixar log compressed file for which zlib is reporting Z_DATA_ERROR from inflate() in tif_pixarlog.c line 816. It attempts to use inflateSync() to re-sync the stream and try to carry on. This issue occurs a few times and is then is followed on by uninitialized data access errors in zlib.

There is identical code in tif_zip.c at line 178. I have another file for which use of uninitialized data is reported in zlib and suspect that it is due to the same problem.

Is it the consensus of opinion that an attempt to recover from Z_DATA_ERROR is valuable? The alternative is to quit right away and hopefully not plow into reading unitialized memory (considered to be a security problem rather than a virtue). Should libtiff try really hard to read apparently corrupted files or can we safely assume that modern computers do not produce useful corrupted files?

Thanks in advance for any informed opinions.

Bob
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Bob Friesenhahn
bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/

Public Key, http://www.simplesystems.org/users/bfriesen/public-key.txt