From: Tycho Andersen <tycho@tycho.pizza>
To: Topi Miettinen <toiwoton@gmail.com>
Cc: linux-modules <linux-modules@vger.kernel.org>,
Kernel Hardening <kernel-hardening@lists.openwall.com>,
"linux-hardening@vger.kernel.org"
<linux-hardening@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: Per-process flag set via prctl() to deny module loading?
Date: Mon, 10 Apr 2023 07:36:16 -0600 [thread overview]
Message-ID: <ZDQQ0B35NcYwQMyy@tycho.pizza> (raw)
In-Reply-To: <640c4327-0b40-f964-0b5b-c978683ac9ba@gmail.com>
On Mon, Apr 10, 2023 at 01:06:00PM +0300, Topi Miettinen wrote:
> I'd propose to add a per-process flag to irrevocably deny any loading of
> kernel modules for the process and its children. The flag could be set (but
> not unset) via prctl() and for unprivileged processes, only when
> NoNewPrivileges is also set. This would be similar to CAP_SYS_MODULE, but
> unlike capabilities, there would be no issues with namespaces since the flag
> isn't namespaced.
>
> The implementation should be very simple.
>
> Preferably the flag, when configured, would be set by systemd, Firejail and
> maybe also container managers. The expectation would be that the permission
> to load modules would be retained only by udev and where SUID needs to be
> allowed (NoNewPrivileges unset).
You can do something like this today via STATIC_USERMODEHELPER without
the need for kernel patches. It is a bit heavyweight for a
general-purpose system though.
Tycho
next prev parent reply other threads:[~2023-04-10 13:36 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-10 10:06 Per-process flag set via prctl() to deny module loading? Topi Miettinen
2023-04-10 13:36 ` Tycho Andersen [this message]
2023-04-10 20:47 ` Topi Miettinen
2023-04-10 21:25 ` Tycho Andersen
2023-04-10 18:37 ` Greg KH
2023-04-10 21:04 ` Topi Miettinen
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