ata: sata_mv:- Handle return value of devm_ioremap.

BugLink: http://bugs.launchpad.net/bugs/1663657
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>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index bd74ee555278513118d057e832b3ec599923bb69..729f26322095e42bd76708237c5ed3a8999f728a 100644 (file)
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -4121,6 +4121,9 @@ static int mv_platform_probe(struct platform_device *pdev)
        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);