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From: Jesse Barnes <jbarnes@virtuousgeek.org>
To: Neil Horman <nhorman@tuxdriver.com>
Cc: greg@kroah.com, linux-pci@vger.kernel.org,
	linux-kernel@vger.kernel.org, akpm@linux-foundation.org
Subject: Re: [PATCH] ibmphp: Fix module ref count underflow
Date: Tue, 16 Dec 2008 10:42:08 -0800	[thread overview]
Message-ID: <200812161042.09345.jbarnes@virtuousgeek.org> (raw)
In-Reply-To: <20081210194334.GA25257@hmsreliant.think-freely.org>

On Wednesday, December 10, 2008 11:43 am Neil Horman wrote:
> Hey-
> 	I happened to notice that the ibmphp hotplug driver does something
> rather silly in its init routine.  It purposely calls module_put so as to
> underflow its module ref count to avoid being removed from the kernel. 
> This is bad practice, and wrong, since it provides a window for subsequent
> module_gets to reset the refcount to zero, allowing an unload to race in
> and cause all sorts of mysterious panics.  If the module is unsafe to load,
> it should inform the kernel as such with a call to __unsafe.  The patch
> below does that.

Thanks Neil, applied this to my for-linus branch since it sounds potentially 
serious (but also low risk since who uses ibmphp anymore? :)

Jesse

  parent reply	other threads:[~2008-12-16 18:42 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-12-10 19:43 [PATCH] ibmphp: Fix module ref count underflow Neil Horman
2008-12-10 22:28 ` Greg KH
2008-12-11  1:28   ` Neil Horman
2008-12-16 18:42 ` Jesse Barnes [this message]
2008-12-16 19:56   ` Neil Horman
2008-12-16 20:52     ` Jesse Barnes
2008-12-17  1:13       ` Neil Horman

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