From 064c3db9c564cc5be514ac21fb4aa26cc33db746 Mon Sep 17 00:00:00 2001
From: Arvind Yadav <arvind.yadav.cs@gmail.com>
Date: Mon, 12 Dec 2016 23:13:27 +0530
Subject: ata: sata_mv:- Handle return value of devm_ioremap.

From: Arvind Yadav <arvind.yadav.cs@gmail.com>

commit 064c3db9c564cc5be514ac21fb4aa26cc33db746 upstream.

Here, If devm_ioremap will fail. It will return NULL.
Then hpriv->base = NULL - 0x20000; 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: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/ata/sata_mv.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -4132,6 +4132,9 @@ static int mv_platform_probe(struct plat
 	host->iomap = NULL;
 	hpriv->base = devm_ioremap(&pdev->dev, res->start,
 				   resource_size(res));
+	if (!hpriv->base)
+		return -ENOMEM;
+
 	hpriv->base -= SATAHC0_REG_BASE;
 
 	hpriv->clk = clk_get(&pdev->dev, NULL);