tty: serial: 8250: 8250_gsc:- Handle return NULL error from ioremap_nocache

Here, If ioremap_nocache will fail. It will return NULL.
Kernel can run into a NULL-pointer dereference.
This error check will avoid NULL pointer dereference.

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_gsc.c b/drivers/tty/serial/8250/8250_gsc.c
index b1e6ae9..63306de 100644 (file)
--- a/drivers/tty/serial/8250/8250_gsc.c
+++ b/drivers/tty/serial/8250/8250_gsc.c
@@ -60,6 +60,10 @@ static int __init serial_init_chip(struct parisc_device *dev)
                                        7272727 : 1843200;
        uart.port.mapbase       = address;
        uart.port.membase       = ioremap_nocache(address, 16);
+       if (!uart.port.membase) {
+               dev_warn(&dev->dev, "Failed to map memory\n");
+               return -ENOMEM;
+       }
        uart.port.irq   = dev->irq;
        uart.port.flags = UPF_BOOT_AUTOCONF;
        uart.port.dev   = &dev->dev;