linux-kernel - Re: [PATCH 0/4] exportfs: add flag to allow marking export operations as only supporting file handles

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: <0974893ac7d97cc709ffa7df52fb5e0b7f502a4c.camel@kernel.org>
Date: Sun, 01 Dec 2024 08:28:05 -0500
From: Jeff Layton <jlayton@...nel.org>
To: Christian Brauner <brauner@...nel.org>, Amir Goldstein
 <amir73il@...il.com>
Cc: Erin Shepherd <erin.shepherd@....eu>, Chuck Lever
 <chuck.lever@...cle.com>, 	linux-fsdevel@...r.kernel.org,
 linux-kernel@...r.kernel.org, 	linux-nfs@...r.kernel.org, stable
 <stable@...nel.org>
Subject: Re: [PATCH 0/4] exportfs: add flag to allow marking export
 operations as only supporting file handles

On Sun, 2024-12-01 at 14:12 +0100, Christian Brauner wrote:
> Hey,
> 
> Some filesystems like kernfs and pidfs support file handles as a
> convenience to enable the use of name_to_handle_at(2) and
> open_by_handle_at(2) but don't want to and cannot be reliably exported.
> Add a flag that allows them to mark their export operations accordingly
> and make NFS check for its presence.
> 
> @Amir, I'll reorder the patches such that this series comes prior to the
> pidfs file handle series. Doing it that way will mean that there's never
> a state where pidfs supports file handles while also being exportable.
> It's probably not a big deal but it's definitely cleaner. It also means
> the last patch in this series to mark pidfs as non-exportable can be
> dropped. Instead pidfs export operations will be marked as
> non-exportable in the patch that they are added in.
> 
> Thanks!
> Christian
> 
> ---
> Christian Brauner (4):
>       exportfs: add flag to indicate local file handles
>       kernfs: restrict to local file handles
>       ovl: restrict to exportable file handles
>       pidfs: restrict to local file handles
> 
>  fs/kernfs/mount.c        | 1 +
>  fs/nfsd/export.c         | 8 +++++++-
>  fs/overlayfs/util.c      | 7 ++++++-
>  fs/pidfs.c               | 1 +
>  include/linux/exportfs.h | 1 +
>  5 files changed, 16 insertions(+), 2 deletions(-)
> ---
> base-commit: 74e20c5946ab3f8ad959ea34f63f21e157d3ebae
> change-id: 20241201-work-exportfs-cd49bee773c5
> 

I've been following the pidfs filehandle discussion and this is exactly
what I was thinking we needed: a way to explicitly label certain
fstypes as unexportable via nfsd.

Reviewed-by: Jeff Layton <jlayton@...nel.org>