Re: Bug in lrzip 0.631-1 (32 bit version) with -d -o - options

[David Balažic <xerces9 at gmail dot com>]

I tried in Ubuntu 32 bit (both the packaged lrzip  and a self compiled
one) and there the problem does not happen, so it looks like either:
 - bad lrzip in cygwin
 - cygwin pipe issues?

Regards,
David


On 25 January 2017 at 23:15, David Balažic <xerces9@gmail.com> wrote:
> Hi!
>
> The 32 bit version of lrzip 0.631-1 contains a bug that corrupts the
> decompressed dat in some circumstances.
>
> I reproduced the problem on 2 PCs (the md5sum of the broken output was
> the same on both systems).
>
> I seems to happen when the (de)compressed file size is bigger than the
> available RAM (note that the 32 bit version uses max 4GB in any case)
> and lrzip resorts to using a temporary file.
>
> See below for reproducing:
>
> $ lrzip -i sda.img.lrz2
> sda.img.lrz2:
> lrzip version: 0.6 file
> Compression: rzip + lzma
> Decompressed file size: 64017212928
> Compressed file size: 7210541304
> Compression ratio: 8.878
> MD5 used for integrity testing
> MD5: 6594f5b0d22efd345003260054165842
>
> $ date; df -h ; TMP=/cygdrive/i/t/tmp/  lrzip -v  -d  -o -
> sda.img.lrz2  | tee >(md5sum --tag) >(sha1sum --tag) > /dev/null   ;
> date
> Tue Jan 24 21:29:01 CET 2017
> Filesystem      Size  Used Avail Use% Mounted on
> C:/cygwin       114G   94G   21G  83% /
> D:              541G  534G  7.1G  99% /cygdrive/d
> I:              391G  279G  113G  72% /cygdrive/i
> Q:               60G   57G  2.8G  96% /cygdrive/q
> The following options are in effect for this DECOMPRESSION.
> Threading is ENABLED. Number of CPUs detected: 4
> Detected 17160601600 bytes ram
> Compression level 7
> Nice Value: 19
> Show Progress
> Verbose
> Output Filename Specified: -
> Temporary Directory set as: /cygdrive/i/t/tmp/
> Outputting to stdout.
> Detected lrzip version 0.6 file.
> MD5 being used for integrity testing.
> Decompressing...
> Unable to decompress entirely in ram, will use physical files
> Dumping temporary file to control->outFILE.
>
> [1]+  Stopped                 TMP=/cygdrive/i/t/tmp/ lrzip -v -d -o -
> sda.img.lrz2 | tee >(md5sum --tag) >(sha1sum --tag) > /dev/null
> Tue Jan 24 21:31:39 CET 2017
>
> stein@hofer8 /cygdrive/i/Zotac_bak
> $ fg
> TMP=/cygdrive/i/t/tmp/ lrzip -v -d -o - sda.img.lrz2 | tee >(md5sum
> --tag) >(sha1sum --tag) > /dev/null
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
> Dumping temporary file to control->outFILE.
>
> Average DeCompression Speed:  0.668MB/s
> Dumping temporary file to control->outFILE.
> [OK] - 64017212928 bytes
> Total time: 25:22:26.25
> SHA1 (-) = 6c519210541eb128c03b7c0f803adb2b46ee2a72
> MD5 (-) = 8bd6ad48f2cea6a710af70b434d57673
>
>
> The correct md5sum is 6594f5b0d22efd345003260054165842.
>
>
> Simply decompressing the file (lrzip -d -o sda.img sda.img.lrz2) to
> filesystem works fine, only when piped to stdout the problem happens.
>
> The 64 bit version does not have this problem.
>
>
> I will check if the same problem happens with the native linux build
> of lrzip (it takes a day...).
>
>
> I tried to reproduce the problem with a smaller file, but there it did
> not happen. Maybe my first test file has some corruption that causes
> this (unlikely).
>
> Some version information (complete cygcheck -s -v -r output attached):
>
> base-cygwin                           3.8-1
> cygwin                                2.6.1-1
> lrzip                                 0.631-1
>
> Regards,
> David

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