linux-kernel - Re: [PATCH] fix pktcdvd breakage from commit e105b8bfc769b0545b6f0f395179d1e43cbee822

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: <ac3eb2510811300557u4922699du87a62cfd29020db1@mail.gmail.com>
Date:	Sun, 30 Nov 2008 14:57:14 +0100
From:	"Kay Sievers" <kay.sievers@...y.org>
To:	"Al Viro" <viro@...iv.linux.org.uk>
Cc:	"Linus Torvalds" <torvalds@...ux-foundation.org>, gregkh@...e.de,
	petero2@...ia.com, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] fix pktcdvd breakage from commit e105b8bfc769b0545b6f0f395179d1e43cbee822

On Sun, Nov 30, 2008 at 14:50, Al Viro <viro@...iv.linux.org.uk> wrote:
> On Sun, Nov 30, 2008 at 02:44:24PM +0100, Kay Sievers wrote:
>
>> >> Which part of the above constitutes a creation of char device node?
>> >
>> > Wait a minute...  Are you saying that something in userland ends up
>> > seeing that sucker, noticing .../dev and proceeding to do mknod?
>>
>> Sure, it does mkod, as the kernel says it should. But that does not
>> cause any real problem.
>
> "It" being udev, presumably?

Yes, udev, mdev, and a few other tools people use to populate /dev
from the kernel supplied device information.

> What a mess...  How does drivers/usb/core/devio.c avoid essentially the same
> problem?

It's a special case, where two "struct device" have the same dev_t,
but they both point to and handle the same device, so it's fine. The
usb_device class is deprecated, no recent distro uses it, and will be
removed some day.

The /sys/dev/ is handled properly by doing:
  usb_classdev_class->dev_kobj = NULL;

Kay
--
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/