[POWERPC] mpc5200-fec: Fix possible NULL dereference in mdio driver

If the reg property is missing from the phy node (unlikely, but possible),
then the kernel will oops with a NULL pointer dereference.  This fixes
it by checking the pointer first.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/net/fec_mpc52xx_phy.c b/drivers/net/fec_mpc52xx_phy.c
index 1837584c4504..6a3ac4ea97e9 100644
--- a/drivers/net/fec_mpc52xx_phy.c
+++ b/drivers/net/fec_mpc52xx_phy.c
@@ -109,7 +109,8 @@ static int mpc52xx_fec_mdio_probe(struct of_device *of, const struct of_device_i
                 int irq = irq_of_parse_and_map(child, 0);
                 if (irq != NO_IRQ) {
                         const u32 *id = of_get_property(child, "reg", NULL);
-                        bus->irq[*id] = irq;
+                        if (id)
+                                bus->irq[*id] = irq;
                 }
         }