[PATCH] gdb/dwarf2read.c: Sanity check DW_AT_sibling values.
Will Newton
will.newton@linaro.org
Tue Nov 5 13:36:00 GMT 2013
On 4 November 2013 15:57, Tom Tromey <tromey@redhat.com> wrote:
>>>>>> "Will" == Will Newton <will.newton@linaro.org> writes:
>
> Will> When reading objects with corrupt debug information it is possible that
> Will> the sibling chain can form a loop, which leads to an infinite loop and
> Will> memory exhaustion.
>
> Will> Avoid this situation by disregarding and DW_AT_sibling values that point
> Will> to a lower address than the current entry.
>
> Thanks for doing this.
>
> Will> + const gdb_byte *sibling_ptr = buffer + dwarf2_get_ref_die_offset (&attr).sect_off;
>
> This line is too long, it should be split somewhere.
Thanks, I'll fix these.
> Will> + if (sibling_ptr < info_ptr)
> Will> + complaint (&symfile_complaints,
> Will> + _("DW_AT_sibling points backwards"));
>
> I wonder whether the check should be "<=".
I'm not sure. It looks to me that info_ptr at this point will point to
the next attribute/DIE which could be a valid sibling?
--
Will Newton
Toolchain Working Group, Linaro
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