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From: "John Ericson" <mail@johnericson.me>
To: "Andy Lutomirski" <luto@kernel.org>,
	"Christian Brauner" <brauner@kernel.org>
Cc: "Li Chen" <me@linux.beauty>, "Cong Wang" <cwang@multikernel.io>,
	linux-arch <linux-arch@vger.kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-fsdevel <linux-fsdevel@vger.kernel.org>,
	linux-api <linux-api@vger.kernel.org>,
	"Arnd Bergmann" <arnd@arndb.de>,
	"Thomas Gleixner" <tglx@kernel.org>,
	"Ingo Molnar" <mingo@redhat.com>,
	"Borislav Petkov" <bp@alien8.de>,
	"Dave Hansen" <dave.hansen@linux.intel.com>,
	"H. Peter Anvin" <hpa@zytor.com>, "Jan Kara" <jack@suse.cz>,
	"Jonathan Corbet" <corbet@lwn.net>,
	"Shuah Khan" <skhan@linuxfoundation.org>,
	"Al Viro" <viro@zeniv.linux.org.uk>,
	"Kees Cook" <kees@kernel.org>,
	"Sergei Zimmerman" <sergei@zimmerman.foo>,
	"Farid Zakaria" <farid.m.zakaria@gmail.com>
Subject: Re: [RFC] Null Namespaces
Date: Tue, 30 Jun 2026 00:25:44 -0400	[thread overview]
Message-ID: <c854819e-598a-4a86-bfc5-ea558101846f@app.fastmail.com> (raw)
In-Reply-To: <CALCETrVuh0-biOw=TgYN9ERTFAoiki57XeZ3S2T3dO2+hL54gA@mail.gmail.com>

On Mon, Jun 29, 2026, at 5:06 PM, Andy Lutomirski wrote:
> But if this happens, maybe we could finally land one of the patches to
> enable unprivileged chroot?  It's been tried a few times.

> If we had a way to make an OFD to a directory that forced
> RESOLVE_BENEATH (or RESOLVE_IN_ROOT) and that propagated that
> restriction to anything you open using it, and if an unprivileged
> process could chroot itself to nullfs, then we would be getting quite
> close to what Capsicum can do.

I just want to briefly say that I agree that these are both things worth
pursuing.

Once the root and working directories are sorted out (whether by nullfs
or by making those optional in `fs_struct`, see my other email), I am
fine putting my yet-unsubmitted patches for the null namespaces
themselves on hold and addressing these things instead. I can indeed see
it may be useful to wrap up such loose ends in VFS-land while we are
here, before switching gears to other namespaces and other subsystems.

John

  reply	other threads:[~2026-06-30  4:26 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-24 22:51 [RFC] Null Namespaces John Ericson
2026-06-24 23:06 ` Andy Lutomirski
2026-06-24 23:20   ` Andy Lutomirski
2026-06-24 23:53     ` John Ericson
2026-06-25  1:10       ` Al Viro
2026-06-25  3:41         ` John Ericson
2026-06-25 15:51           ` Andy Lutomirski
2026-06-25 18:21             ` John Ericson
2026-06-26  0:15           ` Al Viro
2026-06-26 16:26             ` John Ericson
2026-06-29 10:31             ` Christian Brauner
2026-06-24 23:12 ` Al Viro
2026-06-25 21:00   ` H. Peter Anvin
2026-06-25 21:50     ` John Ericson
2026-06-25 23:09       ` Andy Lutomirski
2026-06-26  8:27         ` David Laight
2026-06-26 17:23           ` John Ericson
2026-06-29 10:39       ` Christian Brauner
2026-07-01  9:49         ` Jori Koolstra
2026-07-02 21:28           ` H. Peter Anvin
2026-06-29 11:45 ` Christian Brauner
2026-06-29 21:06   ` Andy Lutomirski
2026-06-30  4:25     ` John Ericson [this message]
2026-07-02  9:34     ` Christian Brauner
2026-07-02 15:43       ` John Ericson
2026-07-03  8:59         ` Christian Brauner
2026-07-03 17:35       ` Directory capability brain dump (Re: [RFC] Null Namespaces) Andy Lutomirski
2026-07-06 14:52       ` [RFC] Null Namespaces Christian Brauner
2026-07-06 16:32         ` Jann Horn
2026-07-06 17:10           ` Andy Lutomirski
2026-07-06 17:04         ` Andy Lutomirski
2026-06-30  2:50   ` John Ericson
2026-06-30  7:14     ` Christian Brauner
2026-06-30 17:20       ` John Ericson
2026-06-30 17:41         ` Andy Lutomirski
2026-07-02  9:29           ` Christian Brauner
2026-06-30 18:05         ` H. Peter Anvin
2026-07-04 13:20 ` Li Chen

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