Re: FAILED: patch "[PATCH] NFC: nfcmrvl_uart: fix OF child-node lookup" failed to apply to 4.9-stable tree

Johan Hovold
2018-11-28T02:14:51Z

On Sun, Nov 11, 2018 at 06:24:37AM -0800, Greg Kroah-Hartman wrote:
>
> The patch below does not apply to the 4.9-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.

This one also depends on

36156f9241cb ("of: add helper to lookup compatible child node")

Johan

> ------------------ original commit in Linus's tree ------------------
>
> From 5bf59773aaf36dd62117dc83d50e1bbf9ef432da Mon Sep 17 00:00:00 2001
> From: Johan Hovold <johan@kernel.org>
> Date: Mon, 27 Aug 2018 10:21:52 +0200
> Subject: [PATCH] NFC: nfcmrvl_uart: fix OF child-node lookup
>
> 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 parent node).
>
> Fixes: e097dc624f78 ("NFC: nfcmrvl: add UART driver")
> Fixes: d8e018c0b321 ("NFC: nfcmrvl: update device tree bindings for Marvell NFC")
> Cc: stable <stable@vger.kernel.org> # 4.2
> Cc: Vincent Cuissard <cuissard@marvell.com>
> Cc: Samuel Ortiz <sameo@linux.intel.com>
> Signed-off-by: Johan Hovold <johan@kernel.org>
> Signed-off-by: Rob Herring <robh@kernel.org>
>
> diff --git a/drivers/nfc/nfcmrvl/uart.c b/drivers/nfc/nfcmrvl/uart.c
> index 91162f8e0366..9a22056e8d9e 100644
> --- a/drivers/nfc/nfcmrvl/uart.c
> +++ b/drivers/nfc/nfcmrvl/uart.c
> @@ -73,10 +73,9 @@ static int nfcmrvl_uart_parse_dt(struct device_node *node,
> struct device_node *matched_node;
> int ret;
>
> - matched_node = of_find_compatible_node(node, NULL, "marvell,nfc-uart");
> + matched_node = of_get_compatible_child(node, "marvell,nfc-uart");
> if (!matched_node) {
> - matched_node = of_find_compatible_node(node, NULL,
> - "mrvl,nfc-uart");
> + matched_node = of_get_compatible_child(node, "mrvl,nfc-uart");
> if (!matched_node)
> return -ENODEV;
> }
>