From: "Serge E. Hallyn" <serge@hallyn.com>
To: Christian Brauner <christian.brauner@ubuntu.com>
Cc: containers@lists.linux-foundation.org,
"Alexander Mihalicyn" <alexander@mihalicyn.com>,
"Mrunal Patel" <mpatel@redhat.com>, "Wat Lim" <watl@google.com>,
"Aleksa Sarai" <cyphar@cyphar.com>,
"Pavel Tikhomirov" <ptikhomirov@virtuozzo.com>,
"Geoffrey Thomas" <geofft@ldpreload.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"Joseph Christopher Sible" <jcsible@cert.org>,
"Mickaël Salaün" <mic@digikod.net>,
"Vivek Goyal" <vgoyal@redhat.com>,
"Giuseppe Scrivano" <gscrivan@redhat.com>,
"Andy Lutomirski" <luto@amacapital.net>,
"Stephane Graber" <stgraber@ubuntu.com>,
"Kees Cook" <keescook@chromium.org>,
"Sargun Dhillon" <sargun@sargun.me>,
"Josh Triplett" <josh@joshtriplett.org>,
linux-kernel@vger.kernel.org
Subject: Re: LPC 2020 Hackroom Session: summary and next steps for isolated user namespaces
Date: Fri, 9 Oct 2020 23:26:06 -0500 [thread overview]
Message-ID: <20201010042606.GA30062@mail.hallyn.com> (raw)
In-Reply-To: <20200830143959.rhosiunyz5yqbr35@wittgenstein>
> 3. Find a way to allow setgroups() in a user namespace while keeping
> in mind the case of groups used for negative access control.
> This was suggested by Josh Triplett and Geoffrey Thomas. Their idea was to
> investigate adding a prctl() to allow setgroups() to be called in a user
> namespace at the cost of restricting paths to the most restrictive
> permission. So if something is 0707 it needs to be treated as if it's 0000
> even though the caller is not in its owning group which is used for negative
> access control (how these new semantics will interact with ACLs will also
> need to be looked into).
I should probably think this through more, but for this problem, would it
not suffice to add a new prevgroups grouplist to the struct cred, maybe
struct group_info *locked_groups, and every time an unprivileged task creates
a new user namespace, add all its current groups to this list?
next prev parent reply other threads:[~2020-10-10 4:35 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-30 14:39 LPC 2020 Hackroom Session: summary and next steps for isolated user namespaces Christian Brauner
2020-10-10 4:26 ` Serge E. Hallyn [this message]
2020-10-11 20:53 ` Josh Triplett
2020-10-12 0:38 ` Andy Lutomirski
2020-10-12 5:01 ` Eric W. Biederman
2020-10-12 15:00 ` Serge E. Hallyn
2020-10-14 19:46 ` Eric W. Biederman
2020-10-15 14:27 ` Serge E. Hallyn
2020-10-17 15:04 ` Eric W. Biederman
2020-10-12 17:05 ` Giuseppe Scrivano
2020-10-13 12:46 ` Serge E. Hallyn
2020-10-13 15:17 ` Giuseppe Scrivano
2020-10-15 14:32 ` Serge E. Hallyn
2020-10-19 12:12 ` Giuseppe Scrivano
2021-04-21 17:27 ` Snaipe
2021-04-22 9:18 ` Giuseppe Scrivano
2021-04-23 14:36 ` Franklin “Snaipe” Mathieu
2021-05-07 13:37 ` Serge E. Hallyn
2021-05-10 13:02 ` Giuseppe Scrivano
2021-05-10 13:57 ` Giuseppe Scrivano
2020-10-15 15:31 ` Enrico Weigelt, metux IT consult
2020-10-17 16:51 ` Eric W. Biederman
2020-10-18 10:20 ` Christian Brauner
2020-10-18 13:05 ` The problem of setgroups and containers Eric W. Biederman
2020-10-19 0:15 ` Eric W. Biederman
2020-10-19 20:07 ` [RFC][PATCH] userns: Limit process in a user namespace to what the creator is allowed Eric W. Biederman
2020-10-20 14:11 ` Christian Brauner
2020-10-29 13:42 ` LPC 2020 Hackroom Session: summary and next steps for isolated user namespaces Enrico Weigelt, metux IT consult
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