[v2] net:ethernet:cavium:octeon:octeon_mgmt: Handle return NULL error from devm_ioremap

[Arvind Yadav]

Here, If devm_ioremap 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...@gmail.com>
---
 drivers/net/ethernet/cavium/octeon/octeon_mgmt.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/cavium/octeon/octeon_mgmt.c 
b/drivers/net/ethernet/cavium/octeon/octeon_mgmt.c
index 4ab404f..33c2fec 100644
--- a/drivers/net/ethernet/cavium/octeon/octeon_mgmt.c
+++ b/drivers/net/ethernet/cavium/octeon/octeon_mgmt.c
@@ -1479,6 +1479,12 @@ static int octeon_mgmt_probe(struct platform_device 
*pdev)
        p->agl = (u64)devm_ioremap(&pdev->dev, p->agl_phys, p->agl_size);
        p->agl_prt_ctl = (u64)devm_ioremap(&pdev->dev, p->agl_prt_ctl_phys,
                                           p->agl_prt_ctl_size);
+       if (!p->mix || !p->agl || !p->agl_prt_ctl) {
+               dev_err(&pdev->dev, "failed to map I/O memory\n");
+               result = -ENOMEM;
+               goto err;
+       }
+
        spin_lock_init(&p->lock);
 
        skb_queue_head_init(&p->tx_list);
-- 
2.7.4