Re: [PATCH 0/2] of: overlay: Crash fix and improvement

From: Rob Herring
Date: Fri Dec 08 2017 - 10:11:22 EST


On Fri, Dec 08, 2017 at 02:13:01PM +0100, Geert Uytterhoeven wrote:
> Hi Pantelis, Rob, Frank,
>
> This patch series fixes memory corruption when applying overlays.
>
> I first noticed this when using OF configfs. After lots of failed
> debugging attempts, I bisected it to "of: overlay: add per overlay sysfs
> attributes", which is not upstream. But that was a red herring: that
> commit enlarged struct fragment to exactly 64-bytes, which just made it
> more likely to cause random corruption when writing beyond the end of an
> array of fragment structures. With the smaller structure size before,
> such writes usually ended up in the unused holes between allocated
> blocks, causing no harm.
>
> The first patch is the real fix, and applies to both v4.15-rc2 and Rob's
> for-next branch.
> The second patch is a small improvement, and applies to Rob's for-next
> branch only.
>
> I've updated my topic/overlays and topic/renesas-overlays branches at
> git://git.kernel.org/pub/scm/linux/kernel/git/geert/renesas-drivers.git
> accordingly.
>
> Thanks!
>
> Geert Uytterhoeven (2):
> of: overlay: Fix out-of-bounds write in init_overlay_changeset()
> of: overlay: Make node skipping in init_overlay_changeset() clearer

I've applied both and am updating my pull req to Linus. I hope that's
the end of it. If further fixes can't be reproduced with mainline, I'm
not going to be inclined to take them for 4.15.

Rob