linux-kernel - Re: [PATCH net-next 0/7] net: Don't use %pK through printk

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: <Z_1XiNY2ujreEo69@google.com>
Date: Mon, 14 Apr 2025 11:44:24 -0700
From: Brian Norris <briannorris@...omium.org>
To: Thomas Weißschuh <thomas.weissschuh@...utronix.de>
Cc: Jeff Johnson <jjohnson@...nel.org>,
	Loic Poulain <loic.poulain@...aro.org>,
	Francesco Dolcini <francesco@...cini.it>,
	Tony Nguyen <anthony.l.nguyen@...el.com>,
	Przemek Kitszel <przemyslaw.kitszel@...el.com>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
	Saeed Mahameed <saeedm@...dia.com>,
	Leon Romanovsky <leon@...nel.org>, Tariq Toukan <tariqt@...dia.com>,
	ath10k@...ts.infradead.org, linux-kernel@...r.kernel.org,
	ath11k@...ts.infradead.org, ath12k@...ts.infradead.org,
	wcn36xx@...ts.infradead.org, linux-wireless@...r.kernel.org,
	intel-wired-lan@...ts.osuosl.org, netdev@...r.kernel.org,
	linux-rdma@...r.kernel.org
Subject: Re: [PATCH net-next 0/7] net: Don't use %pK through printk

On Mon, Apr 14, 2025 at 10:26:01AM +0200, Thomas Weißschuh wrote:
> Furthermore, restricted pointers ("%pK") were never meant to be used
> through printk().

Is this really true? Documentation/admin-guide/sysctl/kernel.rst still
has a section on kptr_restrict which talks about dmesg, CAP_SYSLOG, and
%pK, which sounds like it's intended. But I'm not highly familiar with
this space, so maybe I'm misreading something.

(I do see that commit a48849e2358e ("printk: clarify the documentation
for plain pointer printing") updated
Documentation/core-api/printk-formats.rst.)

In any case, even if the advice has changed, it seems (again, to an
outsider) a bit much to say it was "never" meant to be used through
printk().

Brian