--- /dev/null
+From 447ee1516f19f534a228dda237eddb202f23e163 Mon Sep 17 00:00:00 2001
+From: Yang Yingliang <yangyingliang@huawei.com>
+Date: Thu, 5 May 2022 20:46:21 +0800
+Subject: tty/serial: digicolor: fix possible null-ptr-deref in digicolor_uart_probe()
+
+From: Yang Yingliang <yangyingliang@huawei.com>
+
+commit 447ee1516f19f534a228dda237eddb202f23e163 upstream.
+
+It will cause null-ptr-deref when using 'res', if platform_get_resource()
+returns NULL, so move using 'res' after devm_ioremap_resource() that
+will check it to avoid null-ptr-deref.
+And use devm_platform_get_and_ioremap_resource() to simplify code.
+
+Fixes: 5930cb3511df ("serial: driver for Conexant Digicolor USART")
+Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
+Reviewed-by: Baruch Siach <baruch@tkos.co.il>
+Cc: stable <stable@vger.kernel.org>
+Link: https://lore.kernel.org/r/20220505124621.1592697-1-yangyingliang@huawei.com
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/tty/serial/digicolor-usart.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+--- a/drivers/tty/serial/digicolor-usart.c
++++ b/drivers/tty/serial/digicolor-usart.c
+@@ -476,10 +476,10 @@ static int digicolor_uart_probe(struct p
+ return PTR_ERR(uart_clk);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+- dp->port.mapbase = res->start;
+ dp->port.membase = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(dp->port.membase))
+ return PTR_ERR(dp->port.membase);
++ dp->port.mapbase = res->start;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)