From: Christian Brauner <brauner@kernel.org>
To: Jori Koolstra <jkoolstra@xs4all.nl>, Aleksa Sarai <cyphar@cyphar.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>, Jan Kara <jack@suse.cz>,
Jeff Layton <jlayton@kernel.org>,
Chuck Lever <chuck.lever@oracle.com>,
Alexander Aring <alex.aring@gmail.com>,
Arnd Bergmann <arnd@arndb.de>,
gregkh@linuxfoundation.org,
Andrew Morton <akpm@linux-foundation.org>,
"Liam R . Howlett" <Liam.Howlett@oracle.com>,
Mike Rapoport <rppt@kernel.org>,
David Hildenbrand <david@redhat.com>,
Lorenzo Stoakes <ljs@kernel.org>,
zhang jiao <zhangjiao2@cmss.chinamobile.com>,
Kees Cook <kees@kernel.org>,
Penglei Jiang <superman.xpt@gmail.com>,
Ethan Tidmore <ethantidmore06@gmail.com>,
Oleg Nesterov <oleg@redhat.com>,
Suren Baghdasaryan <surenb@google.com>,
Vlastimil Babka <vbabka@kernel.org>,
wangzijie <wangzijie1@honor.com>, NeilBrown <neil@brown.name>,
Amir Goldstein <amir73il@gmail.com>,
Mateusz Guzik <mjguzik@gmail.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arch@vger.kernel.org, Namjae Jeon <linkinjeon@kernel.org>
Subject: Re: [PATCH] vfs: transitive upgrade restrictions for fds
Date: Tue, 24 Mar 2026 09:41:06 +0100 [thread overview]
Message-ID: <20260324-konfus-gegeben-50960bd07b3b@brauner> (raw)
In-Reply-To: <20260323220029.765874-2-jkoolstra@xs4all.nl>
On Mon, Mar 23, 2026 at 11:00:22PM +0100, Jori Koolstra wrote:
> Add upgrade restrictions to openat2(). Extend struct open_how to allow
> setting transitive restrictions on using file descriptors to open other
> files. A use case for this feature is to block services or containers
> from re-opening/upgrading an O_PATH file descriptor through e.g.
> /proc/<pid>/fd/<nr as O_WRONLY.
>
> The idea for this features comes form the UAPI group kernel feature idea
> list [1].
>
> [1] https://github.com/uapi-group/kernel-features?tab=readme-ov-file#upgrade-masks-in-openat2
>
> Signed-off-by: Jori Koolstra <jkoolstra@xs4all.nl>
> ---
Aleksa has thought long about this feature so I'll let him do the first
pass review here. Historically this was a bit of a can of worms...
next prev parent reply other threads:[~2026-03-24 8:41 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-23 22:00 [RFC PATCH 0/1] vfs: transitive upgrade restrictions for fds Jori Koolstra
2026-03-23 22:00 ` [PATCH] " Jori Koolstra
2026-03-24 8:41 ` Christian Brauner [this message]
2026-03-24 14:37 ` Greg KH
2026-03-26 11:09 ` Jori Koolstra
2026-03-26 15:32 ` Greg KH
2026-03-24 12:31 ` [RFC PATCH 0/1] " Jeff Layton
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