Re: [patch] Fix CVE-2017-9778

[Simon Marchi <simon dot marchi at polymtl dot ca>]

On 2019-04-24 20:56, Kevin Buettner wrote:
> On Wed, 24 Apr 2019 10:27:39 -0600
> Sandra Loosemore <sandra@codesourcery.com> wrote:
>
> >     GDB was failing to catch cases where a corrupt ELF or core file
> >     contained an invalid length value in a Dwarf debug frame FDE 
> > header.
> >     It was checking for buffer overflow but not cases where the length 
> > was
> >     negative or caused pointer wrap-around.
> >
> >     In addition to the additional validity check, this patch cleans up 
> > the
> >     multiple signed/unsigned conversions on the length field so that 
> > an
> >     unsigned representation is used consistently throughout.
> >
> >     2019-04-24  Sandra Loosemore  <sandra@codesourcery.com>
> >     	    Kang Li <kanglictf@gmail.com>
> >
> >     	PR gdb/21600
> >
> >     	* dwarf2-frame.c (read_initial_length): Be consistent about using
> >     	unsigned representation of length.
> >     	(decode_frame_entry_1): Likewise.  Check for wraparound of
> >     	end pointer as well as buffer overflow.
>
> This is okay.
>
> Kevin

I would just suggest using a more descriptive commit title, stating what 
the commit actually changes in the code.  It's still good to reference 
the CVE number, but by itself is not very descriptive.

Thanks,

Simon