From mboxrd@z Thu Jan  1 00:00:00 1970
From: Scott James Remnant <scott@canonical.com>
Date: Tue, 25 Aug 2009 13:31:31 +0000
Subject: Re: [security] Race condition in udev
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On Tue, 2009-08-25 at 15:11 +0200, Florian Zumbiehl wrote:

> > > well, in those two cases always rename()ing the new node into place w=
ould
> > > work, too!? That would be a different strategy than what's in
> > > place at the moment, but it wouldn't need a special case!?
> > >=20
> > The rename() will fail.
>=20
> Because?
>=20
POSIX.

> > > > Or when racing with devmapper which creates /dev/mapper/foo devices=
 at
> > > > basically the same time as udev.
> > >=20
> > > Seriously? How is a piece of code that does the existence check and
> > > the subsequent action depending on the result of that check non-atomi=
cally
> > > supposed to help avoid some race condition resulting from possible
> > > concurrent creation of a device node?!
> > >=20
> > Read the code and find out.  It works.
>=20
> Guess how I found out that it can not work.
>=20
I don't know, you haven't given any detail of any problems you've
encountered.

Scott
--=20
Scott James Remnant
scott@canonical.com

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