linux-kernel - Re: [PATCH net-next v5 1/3] scm: add SO_PASSPIDFD and SCM

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: <20230522131252.4f9959d3@kernel.org>
Date:   Mon, 22 May 2023 13:12:52 -0700
From:   Jakub Kicinski <kuba@...nel.org>
To:     Simon Horman <simon.horman@...igine.com>
Cc:     Christian Brauner <brauner@...nel.org>,
        kernel test robot <lkp@...el.com>,
        Eric Dumazet <edumazet@...gle.com>,
        Alexander Mikhalitsyn <aleksandr.mikhalitsyn@...onical.com>,
        davem@...emloft.net, oe-kbuild-all@...ts.linux.dev,
        linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
        Paolo Abeni <pabeni@...hat.com>,
        Leon Romanovsky <leon@...nel.org>,
        David Ahern <dsahern@...nel.org>,
        Arnd Bergmann <arnd@...db.de>,
        Kees Cook <keescook@...omium.org>,
        Kuniyuki Iwashima <kuniyu@...zon.com>,
        Lennart Poettering <mzxreary@...inter.de>,
        Luca Boccassi <bluca@...ian.org>, linux-arch@...r.kernel.org
Subject: Re: [PATCH net-next v5 1/3] scm: add SO_PASSPIDFD and SCM_PIDFD

On Mon, 22 May 2023 15:19:17 +0200 Simon Horman wrote:
> > TLI, that AF_UNIX can be a kernel module...
> > I'm really not excited in exposing pidfd_prepare() to non-core kernel
> > code. Would it be possible to please simply refuse SO_PEERPIDFD and
> > SCM_PIDFD if AF_UNIX is compiled as a module? I feel that this must be
> > super rare because it risks breaking even simplistic userspace.  
> 
> It occurs to me that it may be simpler to not allow AF_UNIX to be a module.
> But perhaps that breaks something for someone...

Both of the two options (disable the feature with unix=m, make unix
bool) could lead to breakage, I reckon at least the latter makes
the breakage more obvious? So not allowing AF_UNIX as a module
gets my vote as well.

A mechanism of exporting symbols for core/internal use only would 
find a lot of use in networking :(