[PATCH net] net: ibm: emac: Fix NULL pointer dereference in emac_probe

[Rosen Penev]

Move devm_request_irq() after devm_platform_ioremap_resource() so that
dev->emacp is mapped before the interrupt handler can fire.  An early
interrupt hitting emac_irq() would dereference the NULL dev->emacp and
crash.

Fixes: dcc34ef7c834 ("net: ibm: emac: manage emac_irq with devm")
Assisted-by: Opencode:Big-Pickle
Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
---
 drivers/net/ethernet/ibm/emac/core.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/ibm/emac/core.c b/drivers/net/ethernet/ibm/emac/core.c
index b060795dace7..3e8ea0b05619 100644
--- a/drivers/net/ethernet/ibm/emac/core.c
+++ b/drivers/net/ethernet/ibm/emac/core.c
@@ -3044,6 +3044,13 @@ static int emac_probe(struct platform_device *ofdev)
 	if (err)
 		goto err_gone;

+	dev->emacp = devm_platform_ioremap_resource(ofdev, 0);
+	if (IS_ERR(dev->emacp)) {
+		dev_err(&ofdev->dev, "can't map device registers");
+		err = PTR_ERR(dev->emacp);
+		goto err_gone;
+	}
+
 	/* Setup error IRQ handler */
 	dev->emac_irq = platform_get_irq(ofdev, 0);
 	err = devm_request_irq(&ofdev->dev, dev->emac_irq, emac_irq, 0, "EMAC",
@@ -3056,13 +3063,6 @@ static int emac_probe(struct platform_device *ofdev)

 	ndev->irq = dev->emac_irq;

-	dev->emacp = devm_platform_ioremap_resource(ofdev, 0);
-	if (IS_ERR(dev->emacp)) {
-		dev_err(&ofdev->dev, "can't map device registers");
-		err = PTR_ERR(dev->emacp);
-		goto err_gone;
-	}
-
 	/* Wait for dependent devices */
 	err = emac_wait_deps(dev);
 	if (err)
--
2.54.0