Re: Infinite loop in cascade_filter_fn()

From: Carlos Martín Nieto <cmn@elego.de>
Date: Nov 25, 2011, 14:31 UTC
Message-ID: <20111125143131.GA10417@beez.lab.cmartin.tk>
In-Reply-To: <Pine.GSO.4.63.1111231801580.5099@shipon.roxen.com>

On Wed, Nov 23, 2011 at 06:40:47PM +0100, Henrik Grubbström wrote:

Show 5 quoted lines

> Hi.
> 
> My git repository walker just got bitten by what seems to be a
> reasonably new bug in convert.c:cascade_filter_fn() (git 1.7.8.rc3
> (gentoo)).

It looks like it's a bug between cascade_filter_fn and the actual filter function lf_to_crlf_filter_fn that gets triggered when the output buffer is too small. In this particular case, *isize_p=378 and *osize_p=1 which causes cascade_filter_fn to feed the filter data which it can't process because it doesn't have anywhere to put it.

I think that the function assumes that the output buffer is always large enough, but there are many indirections, so it might be an off-by-one.

Show 21 quoted lines

> 
> How to reproduce:
> 
>   git clone git@github.com:pikelang/Pike.git
> 
>   git checkout -f 0e2080f838c6f0bc7d670ac7549676a353451dca^
> 
>   git checkout -f 0e2080f838c6f0bc7d670ac7549676a353451dca
> 
> The first two commands complete as expected, while the last hangs forever.
> Performing the same with git 1.7.6.4 works as expected.
> 
> The problematic file seems to be
> /src/modules/_Crypto/rijndael_ecb_vt.txt which has the attributes:
> text ident eol=crlf
> 
> Thanks,
> 
> --
> Henrik Grubbström					grubba@grubba.org
> Roxen Internet Software AB				grubba@roxen.com