linux-kernel - Re: [PATCH v2] seccomp: add ptrace options for suspend/resume

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: <20150609212222.GE2045@hopstrocity>
Date:	Tue, 9 Jun 2015 15:22:22 -0600
From:	Tycho Andersen <tycho.andersen@...onical.com>
To:	Oleg Nesterov <oleg@...hat.com>, Kees Cook <keescook@...omium.org>,
	Andy Lutomirski <luto@...capital.net>
Cc:	linux-kernel@...r.kernel.org, linux-api@...r.kernel.org,
	Kees Cook <keescook@...omium.org>,
	Andy Lutomirski <luto@...capital.net>,
	Will Drewry <wad@...omium.org>,
	Roland McGrath <roland@...k.frob.com>,
	Pavel Emelyanov <xemul@...allels.com>,
	"Serge E. Hallyn" <serge.hallyn@...ntu.com>
Subject: Re: [PATCH v2] seccomp: add ptrace options for suspend/resume

Hi Kees, Andy,

On Fri, Jun 05, 2015 at 11:16:50PM +0200, Oleg Nesterov wrote:
> Hi Tycho,
> 
> On 06/04, Tycho Andersen wrote:
> > > > +#ifdef CONFIG_CHECKPOINT_RESTORE
> > > > +bool may_suspend_seccomp(void)
> > > > +{
> > > > +	if (!capable(CAP_SYS_ADMIN))
> > > > +		return false;
> > > > +
> > > > +	if (current->seccomp.mode != SECCOMP_MODE_DISABLED)
> > > > +		return false;
> > >
> > > Heh. OK, I won't argue with the new check too ;)
> >
> > Actually now that I think about it I agree with you, these checks
> > don't seem necessary. Even inside a user namespace, if you can ptrace
> > a process you can make it do whatever you want irrespective of
> > seccomp, as long as it has the necessary capabilities. Once the
> > seccomp checks are run after ptrace, they'll be enforced so you
> > couldn't have it call whatever you want in the first place.
> 
> Good ;)
> 
> > Still, perhaps I'm missing something...
> 
> Kees, Andy?

Any thoughts on removing may_suspend_seccomp() all together?

I sent v3 with this still in it, but I can send v4 without it if we
are all in agreement.

Tycho
--
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/