linux-kernel - Re: [PATCH] misc: use a proper range for minor number dynamic allocation

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <20091110171552.GB3628@vespa.holoscopio.com>
Date:	Tue, 10 Nov 2009 15:15:53 -0200
From:	Thadeu Lima de Souza Cascardo <cascardo@...oscopio.com>
To:	Alan Cox <alan@...rguk.ukuu.org.uk>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org, device@...ana.org,
	rubini@...ion.unipv.it, gregkh@...e.de, cluster-devel@...hat.com
Subject: Re: [PATCH] misc: use a proper range for minor number dynamic
	allocation

On Tue, Nov 10, 2009 at 11:09:42AM +0000, Alan Cox wrote:
> > We could consider buggy the caller which asks for the same device name
> > more than once, without unregistering the first device. But better safe
> 
> If they ask for the same name we certainly should. Probably we should
> error that request and use WARN_ON() to shame the offender in
> kerneloops.org.
> 

The current code returns an error. It does not clear the bit in the
allocation bitmap, which is a bug in misc, which my first patch in the
series fixes now.

If it uses the same name, device_create is the responsible for failing.
It already logs that, but it uses no WARN right now. I think this WARN
should be in the driver core, not in misc, so we catch other offenders
as well.

> > than sorry: we should protect the correct drivers from the buggy ones
> > and avoid a depletion of the minor numbers. And, in case the driver core
> > returns another error for another reason (from device_create), we do the
> > right thing.
> 
> Agreed we need to protect the working drivers.
> 
> Alan

So, do you think this should be in 2.6.32 or even go down to stable?

Regards,
Cascardo.

Download attachment "signature.asc" of type "application/pgp-signature" (198 bytes)