linux-kernel - Re: [0/3] 2.6.27.52 stable review

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: <20100814025323.GA4779@suse.de>
Date:	Fri, 13 Aug 2010 19:53:23 -0700
From:	Greg KH <gregkh@...e.de>
To:	Linus Torvalds <torvalds@...ux-foundation.org>
Cc:	Grant Coady <gcoady.lk@...il.com>, linux-kernel@...r.kernel.org,
	stable@...nel.org, stable-review@...nel.org,
	akpm@...ux-foundation.org, alan@...rguk.ukuu.org.uk
Subject: Re: [0/3] 2.6.27.52 stable review

On Fri, Aug 13, 2010 at 05:51:56PM -0700, Linus Torvalds wrote:
> On Fri, Aug 13, 2010 at 5:11 PM, Greg KH <gregkh@...e.de> wrote:
> >
> > That's a warning that current->mm is null.  I don't know enough about
> > the mm subsystem to say if this is normal or not, and I don't at first
> > glance, see how this patch could have caused this to happen.
> 
> We call that whole "expand_stack()" through handle_mm_fault(), and
> that's _not_ called just for the process itself. So "current->mm" is
> sometimes simply the wrong thing to use - like when you access the VM
> of another process (during fork for the argument setup of the new VM,
> or during ptrace etc).
> 
> Which is why I think commit 05fa199d45c should fix it. It makes the
> stack expansion thing use the right mm. Which it just _happened_ to do
> before, because it was always called just from the faulting code where
> current->mm happened to be the right mm.
> 
> But I really don't know if there might be other issues lurking too.

Ok, I'll go add that commit, and I unpacked my older machine that runs
the .27 kernel and will beat on it with that box tomorrow to see if
anything else pops up.

thanks,

greg k-h
--
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/