NFC: nfcmrvl_uart: fix OF child-node lookup

jhovold · robherring · commit 5bf59773aaf3 · 2018-10-23T13:28:53.000-05:00
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: e097dc6 ("NFC: nfcmrvl: add UART driver") Fixes: d8e018c ("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
@@ -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;
 	}
