linux-kernel - Re: [RESEND PATCH v4 0/3] proc: Relax check of mount visibility

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: <m1zgzwm7iv.fsf@fess.ebiederm.org>
Date:   Mon, 22 Feb 2021 09:44:40 -0600
From:   ebiederm@...ssion.com (Eric W. Biederman)
To:     Alexey Gladkov <gladkov.alexey@...il.com>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Linux FS Devel <linux-fsdevel@...r.kernel.org>,
        Alexey Gladkov <legion@...nel.org>,
        Alexander Viro <viro@...iv.linux.org.uk>,
        Kees Cook <keescook@...omium.org>
Subject: Re: [RESEND PATCH v4 0/3] proc: Relax check of mount visibility

Alexey Gladkov <gladkov.alexey@...il.com> writes:

> If only the dynamic part of procfs is mounted (subset=pid), then there is no
> need to check if procfs is fully visible to the user in the new user
> namespace.

A couple of things.

1) Allowing the mount should come in the last patch.  So we don't have a
bisect hazard.

2) We should document that we still require a mount of proc to match on
atime and readonly mount attributes.

3) If we can find a way to safely not require a previous mount of proc
this will be much more valuable.

Eric