Re: [patch] Fix CVE-2017-9778

[Kevin Buettner <kevinb@redhat.com>]

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