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

From: Rob Herring <robh+dt@kernel.org>
To: Johan Hovold <johan@kernel.org>,
	Boris Brezillon <boris.brezillon@bootlin.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Frank Rowand <frowand.list@gmail.com>,
	devicetree@vger.kernel.org,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	stable <stable@vger.kernel.org>,
	Nicolas Ferre <nicolas.ferre@microchip.com>,
	Josh Wu <rainyfeeling@outlook.com>
Subject: Re: [PATCH v2 5/9] mtd: nand: atmel: fix OF child-node lookup
Date: Tue, 23 Oct 2018 13:28:09 -0500	[thread overview]
Message-ID: <CAL_Jsq+fiM8E-za-fKufgDuoDqu3DY5a4bgZOuF3Ssvj2=6ayg@mail.gmail.com> (raw)
In-Reply-To: <20180827094423.GA14967@localhost>

On Mon, Aug 27, 2018 at 4:44 AM Johan Hovold <johan@kernel.org> wrote:
>
> 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@kernel.org> 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@kernel.org> 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@vger.kernel.org>     # 4.11
> > > > > Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
> > > > > Cc: Josh Wu <rainyfeeling@outlook.com>
> > > > > Cc: Boris Brezillon <boris.brezillon@bootlin.com>
> > > > > Signed-off-by: Johan Hovold <johan@kernel.org>
> > > >
> > > > Acked-by: Boris Brezillon <boris.brezillon@bootlin.com>
> > >
> > > 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.

Hi Boris, can you pick this one up. It conflicts with "mtd: rawnand:
atmel: Fix potential NULL pointer dereference"

Rob