linux-kernel - Re: [BUG] perf tools: off-by-one error in map_groups__find

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CABPqkBSWgtwHPzaw6op4Ngc_OAg9Wnp3g0rios88XuP=RegjWw@mail.gmail.com>
Date:	Fri, 3 Oct 2014 12:07:15 +0200
From:	Stephane Eranian <eranian@...gle.com>
To:	Jiri Olsa <jolsa@...hat.com>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Namhyung Kim <namhyung@...nel.org>,
	Arnaldo Carvalho de Melo <acme@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>,
	"mingo@...e.hu" <mingo@...e.hu>, David Ahern <dsahern@...il.com>
Subject: Re: [BUG] perf tools: off-by-one error in map_groups__find_ams()

On Fri, Oct 3, 2014 at 10:09 AM, Jiri Olsa <jolsa@...hat.com> wrote:
> On Thu, Oct 02, 2014 at 06:40:14PM +0200, Stephane Eranian wrote:
>> On Thu, Oct 2, 2014 at 10:36 AM, Jiri Olsa <jolsa@...hat.com> wrote:
>> > On Wed, Oct 01, 2014 at 09:16:31PM +0200, Stephane Eranian wrote:
>> >> Hi,
>> >>
>> >> It appears that there is a off-by-one bug in map_groups__find_ams().
>> >> The upper-bound check in the test below should be >= because
>> >> end = start + len; The end address is outside the range.
>> >>
>> >> Please confirm.
>> >>
>> >>
>> >> int map_groups__find_ams(struct addr_map_symbol *ams, symbol_filter_t filter)
>> >> {
>> >>                 if (ams->addr < ams->map->start || ams->addr > ams->map->end) {
>> >
>> > yep, looks like bug to me
>> >
>> Are you providing a fix or should I?
>
> please go ahead
>
Based on the same reasoning, I am wondering about the following too:

util/map.c:
int map_groups__fixup_overlappings()
{

          after->start = map->end + 1;
                                                  ^^^ should not be there
}
The first byte after a map is at map->end. Range if [start;end[
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/