Re: [stable] please do not merge 058504edd026 (was Re: fs: use after free in /proc/pid/mountinfo)

[Greg KH <greg@kroah.com>]

On Mon, Jul 07, 2014 at 04:06:27PM -0700, Andrew Morton wrote:
> On Mon, 7 Jul 2014 16:05:42 -0700 Greg KH <greg@kroah.com> wrote:
> 
> > On Fri, Jul 04, 2014 at 03:35:54PM -0700, David Rientjes wrote:
> > > On Fri, 4 Jul 2014, Sasha Levin wrote:
> > > 
> > > > > Does this now reproduce on Linus's tree?  If so, does reverting commit
> > > > > 058504edd026 ("fs/seq_file: fallback to vmalloc allocation") prevent this 
> > > > > issue?
> > > > > 
> > > > > This is a use-after-free since the poison value is 0x6b and I'm presuming 
> > > > > that your /proc/self/mountinfo may be larger than PAGE_SIZE in your 
> > > > > testing environment.
> > > > > 
> > > > 
> > > > Good call, reverting that patch made both issues go away.
> > > > 
> > > 
> > > Thanks for checking, Sasha.
> > > 
> > > Stable maintainers, please do not merge commit 058504edd026 ("fs/seq_file: 
> > > fallback to vmalloc allocation") that is annotated with a cc for 
> > > stable@vger.kernel.org in Linus's tree into stable kernels.
> > > 
> > > Although we're at 3.16-rc3, I'm hoping that we can get a fix for the 
> > > use-after-free in the next couple days before asking for a revert.  Sasha 
> > > confirms[*] this commit causes the bug.
> > 
> > I should also drop "Subject: /proc/stat: convert to single_open_size()"
> > from the -stable tree, right?
> > 
> 
> That would be best.

Ok, now dropped, thanks.

greg k-h