linux-kernel - Re: [RFC PATCH v2 4/6] fuse: implementation of the FUSE_LOOKUP

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: <CAJfpegvM7UwdkTG-aaqTxAAqTgfxGO7uAd5cL3dcQUjM90tFuQ@mail.gmail.com>
Date: Tue, 16 Dec 2025 12:07:28 +0100
From: Miklos Szeredi <miklos@...redi.hu>
To: Amir Goldstein <amir73il@...il.com>
Cc: Luis Henriques <luis@...lia.com>, "Darrick J. Wong" <djwong@...nel.org>, 
	Bernd Schubert <bschubert@....com>, Kevin Chen <kchen@....com>, 
	Horst Birthelmer <hbirthelmer@....com>, linux-fsdevel@...r.kernel.org, 
	linux-kernel@...r.kernel.org, Matt Harvey <mharvey@...ptrading.com>, 
	kernel-dev@...lia.com
Subject: Re: [RFC PATCH v2 4/6] fuse: implementation of the FUSE_LOOKUP_HANDLE operation

On Tue, 16 Dec 2025 at 11:52, Amir Goldstein <amir73il@...il.com> wrote:

> Keep in mind that we will need to store the file handle in the fuse_inode.
> Don't you think that it is better to negotiate the max_handle_size even
> if only as an upper limit?

I don't see the point.  The handle will be allocated after the lookup
has completed, and by that time will will know the exact size, so the
maximum is irrelevant.  What am I missing?

> Note that MAX_HANDLE_SZ is not even UAPI.
> It is the upper limit of the moment for the open_by_handle_at() syscall.
> FUSE protocol is by no means obligated to it, but sure we can use that
> as the default upper limit.

Yeah, but even that is excessive, since this will be a non-connectable
one, and need to fit two of them plus a header into a connectable fuse
file handle.

Thanks,
Miklos