Re: [PATCH] /dev/mem: handle out-of-bounds read/write

[Petr Tesarik <ptesarik@suse.cz>]

On Thu, 30 Jan 2014 07:04:07 -0800
Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:

> On Thu, Jan 30, 2014 at 03:03:32PM +0100, Petr Tesarik wrote:
> > On Thu, 30 Jan 2014 05:28:27 -0800
> > Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:
> > 
> > > On Thu, Jan 30, 2014 at 09:48:02AM +0100, Petr Tesarik wrote:
> > > > The loff_t type may be wider than phys_addr_t (e.g. on 32-bit systems).
> > > > Consequently, the file offset may be truncated in the assignment.
> > > > Currently, /dev/mem wraps around, which may cause applications to read
> > > > or write incorrect regions of memory by accident.
> > > 
> > > Does that really happen?  If so, that's a userspace bug, right?
> > 
> > In my case, it was a userspace bug, indeed. But debugging would have
> > been much easier if I saw read() fail with an EOF condition, rather
> > than pretend that it actually read some bytes (from above 4G) on a
> > 32-bit box.
> 
> Thats true.
> 
> Ok, I'll queue this up after 3.14-rc1 is out, thanks.

Hi Greg,

what happened to this patch? I still don't see it in git...

Petr T