linux-kernel - Re: a method to distinguish between syscall-enter/exit-stop

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

Message-ID: <CAGXu5jKHkJcnpbiuYY8BVX0-wOEUDFMx7r8_HJJe2ZDT8p3uvQ@mail.gmail.com>
Date:	Fri, 6 Feb 2015 17:07:41 -0800
From:	Kees Cook <keescook@...omium.org>
To:	"Dmitry V. Levin" <ldv@...linux.org>
Cc:	Andy Lutomirski <luto@...capital.net>,
	LKML <linux-kernel@...r.kernel.org>,
	Will Drewry <wad@...omium.org>,
	Oleg Nesterov <oleg@...hat.com>,
	"x86@...nel.org" <x86@...nel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	Linux MIPS Mailing List <linux-mips@...ux-mips.org>,
	linux-arch <linux-arch@...r.kernel.org>,
	linux-security-module <linux-security-module@...r.kernel.org>,
	Alexei Starovoitov <ast@...mgrid.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Michael Kerrisk-manpages <mtk.manpages@...il.com>
Subject: Re: a method to distinguish between syscall-enter/exit-stop

On Fri, Feb 6, 2015 at 3:17 PM, Dmitry V. Levin <ldv@...linux.org> wrote:
> On Fri, Feb 06, 2015 at 12:07:03PM -0800, Kees Cook wrote:
>> On Fri, Feb 6, 2015 at 11:32 AM, Andy Lutomirski <luto@...capital.net> wrote:
>> > On Fri, Feb 6, 2015 at 11:23 AM, Kees Cook <keescook@...omium.org> wrote:
> [...]
>> >> And an unrelated thought:
>> >>
>> >> 3) Can't we find some way to fix the inability of a ptracer to
>> >> distinguish between syscall-enter-stop and syscall-exit-stop?
>> >
>> > Couldn't we add PTRACE_O_TRACESYSENTRY and PTRACE_O_TRACESYSEXIT along
>> > the lines of PTRACE_O_TRACESYSGOOD?
>>
>> That might be a nice idea. I haven't written a test to see, but what
>> does PTRACE_GETEVENTMSG return on syscall-enter/exit-stop?
>
> The value returned by PTRACE_GETEVENTMSG is the value set along with the
> latest PTRACE_EVENT_*.
> In case of syscall-enter/exit-stop (which is not a PTRACE_EVENT_*),
> there is no particular value set for PTRACE_GETEVENTMSG.

Could we define one to help distinguish?

-Kees

-- 
Kees Cook
Chrome OS Security
--
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/