[debbugs-tracker] bug#33501: closed (Malformed inputs triggering uninitialized memory use in inflate_dynamic())

[GNU bug Tracking System]

Your message dated Fri, 30 Nov 2018 13:03:31 -0800
with message-id <address@hidden>
and subject line Re: bug#33501: Malformed inputs triggering uninitialized 
memory use in inflate_dynamic()
has caused the debbugs.gnu.org bug report #33501,
regarding Malformed inputs triggering uninitialized memory use in 
inflate_dynamic()
to be marked as done.

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33501: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=33501
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> --- Begin Message ---
>
>
>
> Subject: 
>
> Malformed inputs triggering uninitialized memory use in inflate_dynamic()
>
>
>
>
> Date: 
>
> Sun, 25 Nov 2018 16:45:18 +0100
>
>
>
>
> Hi,
>
> I did some testing of gzip with afl-fuzzing and memory sanitizer and it
> ends up finding a use of uninitialized memory on some malformed inputs.
>
> Sample input (base64):
> H4sIADAwMDAwMGQAAAA=
>
> With msan this causes:
>
> ==21601==WARNING: MemorySanitizer: use-of-uninitialized-value
>     #0 0x4affab in inflate_dynamic /f/gzip/gzip-1.9/inflate.c:803:9
>     #1 0x4affab in inflate_block /f/gzip/gzip-1.9/inflate.c:925
>     #2 0x4affab in inflate /f/gzip/gzip-1.9/inflate.c:957
>     #3 0x4c805d in unzip /f/gzip/gzip-1.9/unzip.c:132:19
>     #4 0x4a1234 in treat_file /f/gzip/gzip-1.9/gzip.c:1002:13
>     #5 0x49d760 in main /f/gzip/gzip-1.9/gzip.c:670:13
>     #6 0x7f85c3d724ea in __libc_start_main (/lib64/libc.so.6+0x244ea)
>     #7 0x41c4d9 in _start (/r/gz/gzip+0x41c4d9)
>
> You can reproduce by building gzip with clang+msan, e.g.
> ./configure CC=clang LD=clang CFLAGS="-fsanitize=undefined -U_FORTIFY_SOURCE" 
> LDFLAGS="-fsanitize=undefined -U_FORTIFY_SOURCE"
>
> And then run the above sample with gzip -dc.
>
> (msan is incompatible with fortify source and some distros set it by
> default, so it's better to unset it.)
>
> -- 
> Hanno Böck
> https://hboeck.de/
>
> mail/jabber: address@hidden
> GPG: FE73757FA60E4E21B937579FA5880072BBB51E42
>
>
>
> --- End Message ---

--- Begin Message --- Subject: Re: bug#33501: Malformed inputs triggering uninitialized memory use in inflate_dynamic() Date: Fri, 30 Nov 2018 13:03:31 -0800 User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.3.1 Thanks for the fix. I installed the attached patch into the GNU gzip master and am marking this bug as done.

0001-gzip-fix-use-of-uninitialized-memory.patch
Description: Text Data

--- End Message ---