From: Andrei Vagin <avagin@gmail.com>
To: Casey Schaufler <casey@schaufler-ca.com>
Cc: "Adrian Reber" <areber@redhat.com>,
"Christian Brauner" <christian.brauner@ubuntu.com>,
"Eric Biederman" <ebiederm@xmission.com>,
"Pavel Emelyanov" <ovzxemul@gmail.com>,
"Oleg Nesterov" <oleg@redhat.com>,
"Dmitry Safonov" <0x7f454c46@gmail.com>,
"Nicolas Viennot" <Nicolas.Viennot@twosigma.com>,
"Michał Cłapiński" <mclapinski@google.com>,
"Kamil Yurtsever" <kyurtsever@google.com>,
"Dirk Petersen" <dipeit@gmail.com>,
"Christine Flood" <chf@redhat.com>,
"Mike Rapoport" <rppt@linux.ibm.com>,
"Radostin Stoyanov" <rstoyanov1@gmail.com>,
"Cyrill Gorcunov" <gorcunov@openvz.org>,
"Serge Hallyn" <serge@hallyn.com>,
"Stephen Smalley" <stephen.smalley.work@gmail.com>,
"Sargun Dhillon" <sargun@sargun.me>,
"Arnd Bergmann" <arnd@arndb.de>,
"Aaron Goidel" <acgoide@tycho.nsa.gov>,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org, selinux@vger.kernel.org,
"Eric Paris" <eparis@parisplace.org>,
"Jann Horn" <jannh@google.com>
Subject: Re: [PATCH] capabilities: Introduce CAP_RESTORE
Date: Fri, 22 May 2020 21:27:49 -0700 [thread overview]
Message-ID: <20200523042749.GA19115@gmail.com> (raw)
In-Reply-To: <dc86dffb-c7f8-15bb-db4e-be135da650cc@schaufler-ca.com>
On Fri, May 22, 2020 at 09:40:37AM -0700, Casey Schaufler wrote:
> On 5/21/2020 10:53 PM, Adrian Reber wrote:
> > There are probably a few more things guarded by CAP_SYS_ADMIN required
> > to run checkpoint/restore as non-root,
>
> If you need CAP_SYS_ADMIN anyway you're not gaining anything by
> separating out CAP_RESTORE.
>
> > but by applying this patch I can
> > already checkpoint and restore processes as non-root. As there are
> > already multiple workarounds I would prefer to do it correctly in the
> > kernel to avoid that CRIU users are starting to invent more workarounds.
>
> You've presented a couple of really inappropriate implementations
> that would qualify as workarounds. But the other two are completely
> appropriate within the system security policy. They don't "get around"
> the problem, they use existing mechanisms as they are intended.
>
With CAP_CHECKPOINT_RESTORE, we will need to use the same mechanisms.
The problem is that CAP_SYS_ADMIN is too wide. If a process has
CAP_SYS_ADMIN, it can do a lot of things and the operation of forking a
process with a specified pid isn't the most dangerous one in this case.
Offten security policies don't allow to grant CAP_SYS_ADMIN to any
third-party tools even in non-root user namespaces.
next prev parent reply other threads:[~2020-05-23 4:27 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-22 5:53 [PATCH] capabilities: Introduce CAP_RESTORE Adrian Reber
2020-05-22 7:53 ` Christian Brauner
2020-05-22 18:02 ` Andrei Vagin
2020-05-22 13:41 ` Christian Brauner
2020-05-22 16:40 ` Casey Schaufler
2020-05-23 4:27 ` Andrei Vagin [this message]
2020-05-25 2:01 ` Casey Schaufler
2020-05-25 8:05 ` Adrian Reber
2020-05-25 18:55 ` Casey Schaufler
2020-05-27 13:48 ` Adrian Reber
2020-05-27 15:57 ` Casey Schaufler
2020-05-27 16:37 ` Nicolas Viennot
2020-05-27 16:46 ` Casey Schaufler
2020-05-26 13:59 ` Eric W. Biederman
[not found] ` <CALKUemw0UZ67yaDwAomHh0n8QZfjd52QvgEXTJ4R3JSrQjZX9g@mail.gmail.com>
2020-05-26 19:19 ` Casey Schaufler
2020-05-26 19:51 ` Jann Horn
2020-05-27 14:14 ` Adrian Reber
2020-05-27 15:29 ` Christian Brauner
2020-05-27 18:05 ` Nicolas Viennot
2020-05-28 9:48 ` Christian Brauner
2020-06-08 2:09 ` Andrei Vagin
2020-05-25 21:53 ` Jann Horn
2020-05-26 9:09 ` Radostin Stoyanov
2020-06-12 0:17 ` Matt Helsley
2020-06-12 14:39 ` Christian Brauner
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