From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Petr Tesarik <ptesarik@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] /dev/mem: handle out-of-bounds read/write
Date: Thu, 30 Jan 2014 07:04:07 -0800 [thread overview]
Message-ID: <20140130150407.GC1388@kroah.com> (raw)
In-Reply-To: <20140130150332.64419aee@hananiah.suse.cz>
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.
greg k-h
next prev parent reply other threads:[~2014-01-30 15:03 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-30 8:48 [PATCH] /dev/mem: handle out-of-bounds read/write Petr Tesarik
2014-01-30 13:28 ` Greg Kroah-Hartman
2014-01-30 14:03 ` Petr Tesarik
2014-01-30 15:04 ` Greg Kroah-Hartman [this message]
2014-04-01 9:29 ` Petr Tesarik
2014-04-01 15:44 ` Greg Kroah-Hartman
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