linux-kernel - Re: [PATCH] x86: defconfig: Enable CONFIG

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: <547B8731.90305@nod.at>
Date:	Sun, 30 Nov 2014 22:08:01 +0100
From:	Richard Weinberger <richard@....at>
To:	Dave Chinner <david@...morbit.com>
CC:	x86@...nel.org, tglx@...utronix.de, mingo@...hat.com,
	hpa@...or.com, gregkh@...uxfoundation.org,
	rafael.j.wysocki@...el.com, pebolle@...cali.nl,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] x86: defconfig: Enable CONFIG_FHANDLE

Am 30.11.2014 um 21:54 schrieb Dave Chinner:
> On Wed, Nov 26, 2014 at 12:36:52AM +0100, Richard Weinberger wrote:
>> systemd has a hard dependency on CONFIG_FHANDLE.
>> If you run systemd with CONFIG_FHANDLE=n it will somehow
>> boot but fail to spawn a getty or other basic services.
>> As systemd is now used by most x86 distributions it
>> makes sense to enabled this by default and save kernel
>> hackers a lot of value debugging time.
> 
> The bigger question to me is this: why does systemd need to
> store/open by handle rather than just opening paths directly when
> needed? This interface is intended for stable, pathless access to
> inodes across unmount/mount contexts (e.g. userspace NFS servers,
> filesystem backup programs, etc) so I'm curious as to the problem
> systemd is solving using this interface. I just can't see the
> problem being solved here, and why path based security checks on
> every open() aren't necessary...

Digging inter systemd source shows that they are using name_to_handle_at()
to get the mount id of a given path.
The actual struct file_handle result is always ignored.

Thanks,
//richard
--
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/