From: Mark Wielaard <mark@klomp.org>
To: Ulf Hermann <ulf.hermann@qt.io>, elfutils-devel@sourceware.org
Subject: Re: [PATCH 1/2 v2] Don't overflow in __libdw_in_section
Date: Thu, 14 Dec 2017 13:43:00 -0000 [thread overview]
Message-ID: <1513259021.15696.80.camel@klomp.org> (raw)
In-Reply-To: <5ae489eb-3981-24b4-294a-734b1c52731d@qt.io>
Hi Ulf,
(Meta, I have some trouble applying this with git am, it thinks the
patch is malformed. But I can apply by hand of course.)
On Fri, 2017-12-08 at 16:05 +0100, Ulf Hermann wrote:
>
> +2017-05-09 Ulf Hermann <ulf.hermann@qt.io>
> +
> + * libdwP.h: Fix check for the upper border of the range in
> __libdw_in_section.
> +
> 2017-11-03 Mark Wielaard <mark@klomp.org>
> * dwarf_getlocation.c (__libdw_intern_expression): Handle
> diff --git a/libdw/libdwP.h b/libdw/libdwP.h
> index 78c0013..e092d8e 100644
> --- a/libdw/libdwP.h
> +++ b/libdw/libdwP.h
> @@ -643,7 +643,8 @@ __libdw_in_section (Dwarf *dbg, int sec_index,
> if (data == NULL)
> return false;
> if (unlikely (addr < data->d_buf)
> - || unlikely (data->d_size - (addr - data->d_buf) < size))
> + || unlikely (data->d_size < size)
> + || unlikely ((size_t)(addr - data->d_buf) > data->d_size -
> size))
> {
> __libdw_seterrno (DWARF_E_INVALID_OFFSET);
> return false;
The transformation seems correct. But if we can overflow/underflow
here, do we have the same problem in __libdw_offset_in_section where we
check data->d_size - offset < size, with offset a Dwarf_Off?
Thanks,
Mark
next prev parent reply other threads:[~2017-12-14 13:43 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-08 15:05 Ulf Hermann
2017-12-14 13:43 ` Mark Wielaard [this message]
2017-12-14 13:55 ` Ulf Hermann
2017-12-20 18:05 ` Mark Wielaard
2017-12-21 13:47 ` Ulf Hermann
2017-12-21 20:22 ` Mark Wielaard
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