linux-kernel - Re: ETXTBSY window in _

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: <7a2513ea-a144-4981-906a-7036d92d4dcb@app.fastmail.com>
Date: Mon, 01 Sep 2025 15:57:21 -0400
From: "Colin Walters" <walters@...bum.org>
To: "Mateusz Guzik" <mjguzik@...il.com>,
 "Alexander Monakov" <amonakov@...ras.ru>
Cc: linux-fsdevel@...r.kernel.org, "Al Viro" <viro@...iv.linux.org.uk>,
 "Christian Brauner" <brauner@...nel.org>, "Jan Kara" <jack@...e.cz>,
 linux-kernel@...r.kernel.org
Subject: Re: ETXTBSY window in __fput



On Mon, Sep 1, 2025, at 2:39 PM, Mateusz Guzik wrote:
> 
> The O_CLOFORM idea was accepted into POSIX and recent-ish implemented in
> all the BSDs (no, really) and illumos, but got NAKed in Linux. It's also
> a part of pig's attire so I think that's the right call.

Do you have a reference handy for that NAK?

> To that end, my sketch of a suggestion boils down to a new API which
> allows you to construct a new process one step at a time 

In this vein I think io_uring_spawn work sounds like the best: https://lwn.net/Articles/908268/

However...if we predicate any solution to this problem on changing every single codebase which is spawning processes, it's going to take a long time. I think changing the few special cases around "sealing" (fsverity and write + fexecve()) is more tractable.