From: Greg KH <greg@kroah.com>
To: Tejun Heo <tj@kernel.org>
Cc: Colin Guthrie <cguthrie@mandriva.org>,
Kay Sievers <kay.sievers@vrfy.org>,
Linux Kernel <linux-kernel@vger.kernel.org>
Subject: Re: get_device_parent() race bug
Date: Mon, 5 Oct 2009 07:22:01 -0700 [thread overview]
Message-ID: <20091005142201.GA21891@kroah.com> (raw)
In-Reply-To: <4AC7EDD7.3080906@kernel.org>
On Sun, Oct 04, 2009 at 09:35:35AM +0900, Tejun Heo wrote:
> Tejun Heo wrote:
> > Hello, Greg, Kay, Guthrie.
> >
> > This problem was reported in bko#14023. (aiee.. again, sorry about
> > the delay)
> >
> > http://bugzilla.kernel.org/show_bug.cgi?id=14023
> >
> > sysfs is creating several devices in cuse class concurrently and with
> > CONFIG_SYSFS_DEPRECATED turned off, it triggers the following oops.
> >
> > BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
>
> Ping. This one needs to be fixed in -stable. It can be triggered by
> other char devices too.
Sorry, been slowly catching up...
This can be triggered by char devices? Huh? How? I don't see the
failure path that is happening here.
And char devices shouldn't really be using the kobject at all, except
for a very basic reference count.
I keep threatening to rip kobject out of a char device and just use a
kref, as that is all that is really needed. Well, that and the kmap
stuff, but again, it's not a "real" kobject being used there...
Perhaps now is the time to do this.
thanks,
greg k-h
next prev parent reply other threads:[~2009-10-05 14:23 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-25 8:22 get_device_parent() race bug Tejun Heo
2009-10-04 0:35 ` Tejun Heo
2009-10-05 14:22 ` Greg KH [this message]
2009-10-06 1:15 ` Tejun Heo
2009-10-06 3:05 ` Greg KH
2009-10-06 3:29 ` Kay Sievers
2009-10-05 23:39 ` Greg KH
2009-10-06 1:35 ` Tejun Heo
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