linux-kernel - Re: [PATCH RFC] [PATCH] drivers/scsi/ch.c: Remove BKL in ch

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: <20091011165408.51d4f413@lxorguk.ukuu.org.uk>
Date:	Sun, 11 Oct 2009 16:54:08 +0100
From:	Alan Cox <alan@...rguk.ukuu.org.uk>
To:	Arjan van de Ven <arjan@...radead.org>
Cc:	John Kacur <jkacur@...hat.com>, linux-kernel@...r.kernel.org,
	Thomas Gleixner <tglx@...utronix.de>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Ingo Molnar <mingo@...e.hu>,
	Christoph Hellwig <hch@...radead.org>,
	Jonathan Corbet <corbet@....net>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Vincent Sanders <vince@...tec.co.uk>,
	linux-scsi@...r.kernel.org
Subject: Re: [PATCH RFC] [PATCH] drivers/scsi/ch.c: Remove BKL in ch_open

> > I'm not so sure. In fact there are some quite umm interesting
> > questions about this code, and some of them are shared with other
> > modules too.
> > 
> > Consider the following sequence
> > 
> > 		CPU1				CPU2
> > 	register_chrdev
> > 		ok
> > 						open device
> > 						takes lock
> 
> 
> but open does not take the BKL, so the BKL is not protecting you at
> all against this..

But module load/unload does - so while the change doesn't appear to cause
any problems there is an underlying problem here that wants looking at.
--
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/