linux-kernel - Re: CAP_SYSLOG, 2.6.38 and user space

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: <20110204110842.33da9ac2@lxorguk.ukuu.org.uk>
Date:	Fri, 4 Feb 2011 11:08:42 +0000
From:	Alan Cox <alan@...rguk.ukuu.org.uk>
To:	Gergely Nagy <algernon@...abit.hu>
Cc:	Marc Koschewski <marc@...nowledge.org>, david@...g.hm,
	"Serge E. Hallyn" <serge@...lyn.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	James Morris <jmorris@...ei.org>
Subject: Re: CAP_SYSLOG, 2.6.38 and user space

> Having both CAP_SYS_ADMIN and CAP_SYSLOG at the same time, for the sole
> purpose of reading kernel log messages would kind of defeat the purpose
> of CAP_SYSLOG. Therefore, a solution that allows both at the same time
> doesn't look all that good to me.

If you do it right you don't need both, you need either, so old code will
use CAP_SYS_ADMIN and work, newer code will use CAP_SYSLOG and work but
hold less rights. In a couple of years you can then drop the
CAP_SYS_ADMIN ability to read log files, providing it is in the list of
API deprecations soon...

> However, having it toggle-able does, and solves all my worries at least:
> defaulting to CAP_SYS_ADMIN maintains backwards compatibility, upgraded
> systems can switch to CAP_SYSLOG if and when the system is ready for
> that. All's well!

Still a mess, we don't break ABIs at random so this patch needs reverting
or fixing ASAP, otherwise Linus will just revert it anyway..

Alan
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/