lkml.org 
[lkml]   [2019]   [Mar]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [BACKPORT 4.4.y 01/25] mmc: pwrseq: constify mmc_pwrseq_ops structures
On Tue, Mar 26, 2019 at 2:22 AM Greg KH <gregkh@linuxfoundation.org> wrote:
> On Fri, Mar 22, 2019 at 04:43:52PM +0100, Arnd Bergmann wrote:

> > }
> >
> > -static struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = {
> > +static const struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = {
> > .pre_power_on = mmc_pwrseq_simple_pre_power_on,
> > .post_power_on = mmc_pwrseq_simple_post_power_on,
> > .power_off = mmc_pwrseq_simple_power_off,
>
> Why is this needed for a stable patch? It doesn't fix a bug, it just
> looks like it is a "nice thing" to have, right? I don't think any later
> patch in this series relies it it, or am I missing something?

Right, the benefit here is rather small. In theory, any structure of
function pointers is a place into which an exploit can be placed
in case someone finds a way to modify a few bytes of kernel
memory. Placing the structures in read-only memory make this
a little harder (it doesn't prevent rowhammer attacks though).

Dropping this patch is certainly fine with me, as we have a large
supply of other structure definitions like this, and we wont' get close to
plugging enough of them in stable kernels.

Arnd

\
 
 \ /
  Last update: 2019-03-26 09:13    [W:1.109 / U:0.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site