linux-kernel - Re: check capabilities in open()

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] [day] [month] [year] [list]

Date:	Mon, 26 Jul 2010 20:52:35 +0400
From:	Vasiliy Kulikov <segooon@...il.com>
To:	Ted Ts'o <tytso@....edu>, Al Viro <viro@...IV.linux.org.uk>,
	kernel-janitors@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: check capabilities in open()

On Mon, Jul 26, 2010 at 07:23 -0400, Ted Ts'o wrote:
> The reason why the apm device needed to sample the suser() bit is that
> it can be opened by root and non-root processes, but it wanted to
> extend the Unix/Linux paradigm that privileges are tested at open()
> time.
Yes, it's exactly that I mean, check at open() time and grand high or
less priviledges.

> 
> So this is a not a bug, but quite deliberately, by design.
If it is explicitly designed to check UID at open() time and to have 2
kinds of file descriptors - priviledged and nonpriviledged, I'm fine
with this.

I wanted kernel community to draw attention because this moment was
not obviously for me and I thought it was a design flaw. Now I'm pleased
with your explanation, thank you.
--
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/