[PATCH 4.9 022/107] can: mpc5xxx_can: check of_iomap return before use

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Nicholas Mc Guire <hof...@osadl.org>

[ Upstream commit b5c1a23b17e563b656cc9bb76ce5323b997d90e8 ]

of_iomap() can return NULL so that return needs to be checked and NULL
treated as failure. While at it also take care of the missing
of_node_put() in the error path.

Signed-off-by: Nicholas Mc Guire <hof...@osadl.org>
Fixes: commit afa17a500a36 ("net/can: add driver for mscan family & 
mpc52xx_mscan")
Signed-off-by: Marc Kleine-Budde <m...@pengutronix.de>
Signed-off-by: Sasha Levin <alexander.le...@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/net/can/mscan/mpc5xxx_can.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/net/can/mscan/mpc5xxx_can.c
+++ b/drivers/net/can/mscan/mpc5xxx_can.c
@@ -86,6 +86,11 @@ static u32 mpc52xx_can_get_clock(struct
                return 0;
        }
        cdm = of_iomap(np_cdm, 0);
+       if (!cdm) {
+               of_node_put(np_cdm);
+               dev_err(&ofdev->dev, "can't map clock node!\n");
+               return 0;
+       }
 
        if (in_8(&cdm->ipb_clk_sel) & 0x1)
                freq *= 2;