Re: [PATCH v2 5/9] mtd: nand: atmel: fix OF child-node lookup

From: Johan Hovold
Date: Mon Aug 27 2018 - 05:44:29 EST


On Mon, Aug 27, 2018 at 10:48:42AM +0200, Boris Brezillon wrote:
> On Mon, 27 Aug 2018 10:44:14 +0200
> Johan Hovold <johan@xxxxxxxxxx> wrote:
>
> > On Mon, Aug 27, 2018 at 10:28:20AM +0200, Boris Brezillon wrote:
> > > Hi Johan
> > >
> > > On Mon, 27 Aug 2018 10:21:49 +0200
> > > Johan Hovold <johan@xxxxxxxxxx> wrote:
> > >
> > > > Use the new of_get_compatible_child() helper to lookup the nfc child
> > > > node instead of using of_find_compatible_node(), which searches the
> > > > entire tree from a given start node and thus can return an unrelated
> > > > (i.e. non-child) node.
> > > >
> > > > This also addresses a potential use-after-free (e.g. after probe
> > > > deferral) as the tree-wide helper drops a reference to its first
> > > > argument (i.e. the node of the device being probed).
> > > >
> > > > While at it, also fix a related nfc-node reference leak.
> > > >
> > > > Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
> > > > Cc: stable <stable@xxxxxxxxxxxxxxx> # 4.11
> > > > Cc: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
> > > > Cc: Josh Wu <rainyfeeling@xxxxxxxxxxx>
> > > > Cc: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
> > > > Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> > >
> > > Acked-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
> >
> > Thanks for the ack.
> >
> > > I'll let Miquel queue this patch to the nand/next branch, unless you
> > > want it to be merged in 4.19, in which case I'll queue it to the
> > > mtd/fixes branch.
> >
> > Note that there's a dependency on the first patch of the series which
> > adds the new helper.
>
> I was not Cc-ed on this patch :P.

Yeah, sorry about that. I made sure everyone was CCed on the
cover letter, but guess I could have reused that list for the helper as
well.

> > Rob can pick up the entire series if the various
> > maintainers agree, otherwise I'll try to get at the least the helper
> > into -rc2.
>
> If everything goes in 4.19-rc2 through Rob's tree that's fine, but if
> it's queued for 4.20 we might need an immutable tag just in case we
> queue conflicting changes to the NAND tree.

Ok, thanks.

Johan