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

[Boris Brezillon]

On Thu, 15 Nov 2018 15:26:48 +0100
Johan Hovold <johan@xxxxxxxxxx> wrote:

> On Tue, Oct 23, 2018 at 08:51:17PM +0200, Boris Brezillon wrote:
> > On Tue, 23 Oct 2018 13:28:09 -0500
> > Rob Herring <robh+dt@xxxxxxxxxx> wrote:
> >   
> > > On Mon, Aug 27, 2018 at 4:44 AM Johan Hovold <johan@xxxxxxxxxx> 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@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.    
> > > 
> > > Hi Boris, can you pick this one up. It conflicts with "mtd: rawnand:
> > > atmel: Fix potential NULL pointer dereference"  
> > 
> > Sure, I'll queue it for -rc2.  
> 
> This one hasn't showed up in -next yet, so sending a reminder.

Applied (thanks for the reminder, I had forgotten :-)). It should show
up in -rc4.

Thanks,

Boris