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

From: Greg Kroah-Hartman
Date: Tue Apr 01 2014 - 11:42:20 EST


On Tue, Apr 01, 2014 at 11:29:30AM +0200, Petr Tesarik wrote:
> On Thu, 30 Jan 2014 07:04:07 -0800
> Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxxx> 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...

You got an email when it went into my git tree, and is set to be merged
to Linus for 3.15-rc1.

greg k-h
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/