Re: [PATCH] rtc: fix kernel panic on second use of SIGIO nofitication

[Alessandro Zummo <alessandro.zummo@towertech.it>]

On Thu, 2 Oct 2008 14:49:41 -0700
Andrew Morton <akpm@linux-foundation.org> wrote:

> On Sun, 14 Sep 2008 20:11:27 +0200
> Marcin Slusarz <marcin.slusarz@gmail.com> wrote:
> 
> > When user space uses SIGIO notification and forgets to disable it before
> > closing file descriptor, rtc->async_queue contains stale pointer to struct
> > file. When user space enables again SIGIO notification in different process,
> > kernel dereferences this (poisoned) pointer and crashes.
> > 
> > So disable SIGIO notification on close.
> > 
> 
> David, Alessandro: can we please have a review-n-ack of this one for
> 2.6.27 and earlier?  
> 
> Thanks.
> 
> From: Marcin Slusarz <marcin.slusarz@gmail.com>
> 
> When userspace uses SIGIO notification and forgets to disable it before
> closing file descriptor, rtc->async_queue contains stale pointer to struct
> file.  When user space enables again SIGIO notification in different
> process, kernel dereferences this (poisoned) pointer and crashes.
> 
> So disable SIGIO notification on close.

 [...]
> 
> Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
> Cc: Alessandro Zummo <alessandro.zummo@towertech.it>
> Cc: David Brownell <dbrownell@users.sourceforge.net>
> Cc: <stable@kernel.org>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

 
 Acked-by: Alessandro Zummo <a.zummo@towertech.it>

-- 

 Best regards,

 Alessandro Zummo,
  Tower Technologies - Torino, Italy

  http://www.towertech.it