Re: [RFC 00/06] printk: add more new kernel pointer filter options.

From: Greg KH
Date: Thu May 18 2017 - 10:13:47 EST


On Tue, May 16, 2017 at 09:36:37PM +0000, Roberts, William C wrote:
>
>
> > -----Original Message-----
> > From: Sergey Senozhatsky [mailto:sergey.senozhatsky.work@xxxxxxxxx]
> > Sent: Wednesday, May 10, 2017 6:38 PM
> > To: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Cc: kernel-hardening@xxxxxxxxxxxxxxxxxx; Petr Mladek <pmladek@xxxxxxxx>;
> > Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>; linux-
> > kernel@xxxxxxxxxxxxxxx; Catalin Marinas <catalin.marinas@xxxxxxx>; Will
> > Deacon <will.deacon@xxxxxxx>; Steven Rostedt <rostedt@xxxxxxxxxxx>;
> > Roberts, William C <william.c.roberts@xxxxxxxxx>; Chris Fries
> > <cfries@xxxxxxxxxx>; Dave Weinstein <olorin@xxxxxxxxxx>
> > Subject: Re: [RFC 00/06] printk: add more new kernel pointer filter options.
> >
> > Hello Greg,
> >
> > On (05/05/17 21:06), Greg KH wrote:
> > > Here's a short patch series from Chris Fries and Dave Weinstein that
> > > implement some new restrictions when printing out kernel pointers, as
> > > well as the ability to whitelist kernel pointers where needed.
> > >
> > > These patches are based on work from William Roberts, and also is
> > > inspired by grsecurity's %pP to specifically whitelist a kernel
> > > pointer, where it is always needed, like the last patch in the series
> > > shows, in the UIO drivers (UIO requires that you know the address,
> > > it's a hardware address, nothing wrong with seeing that...)
> > >
> > > I haven't done much to this patch series, only forward porting it from
> > > an older kernel release (4.4) and a few minor tweaks. It applies
> > > cleanly on top of 4.11 as well as Linus's current development tree
> > > (10502 patches into the 4.12-rc1 merge window). I'm posting it now
> > > for comments if anyone sees anything wrong with this approach
> >
> > overall, I don't see anything wrong.
> >
> > > or thinks the things that are being whitelisted should not be?
> >
> > can't say for sure, sorry.
> >
> > -ss
>
> I almost missed this, none of the mail was delivered to my inbox...

Why not? Did I get the address wrong?

> Anyways, I am glad to see this revived and I don't have any
> Comments besides thanks.

Acks for the patches are always appreciated :)

I'll revise this in the next few weeks and send out a new series.

thanks,

greg k-h