wimax: i2400m - prevent a possible kernel bug due to missing fw_name string

[ Upstream commit 4eee6a3a04e8bb53fbe7de0f64d0524d3fbe3f80 ]

This happened on a machine with a custom hotplug script calling nameif,
probably due to slow firmware loading. At the time nameif uses ethtool
to gather interface information, i2400m->fw_name is zero and so a null
pointer dereference occurs from within i2400m_get_drvinfo().

Signed-off-by: Phil Sutter <phil.sutter@viprinet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/net/wimax/i2400m/netdev.c b/drivers/net/wimax/i2400m/netdev.c
index 64a1106..4697cf3 100644 (file)
--- a/drivers/net/wimax/i2400m/netdev.c
+++ b/drivers/net/wimax/i2400m/netdev.c
@@ -607,7 +607,8 @@ static void i2400m_get_drvinfo(struct net_device *net_dev,
        struct i2400m *i2400m = net_dev_to_i2400m(net_dev);
 
        strncpy(info->driver, KBUILD_MODNAME, sizeof(info->driver) - 1);
-       strncpy(info->fw_version, i2400m->fw_name, sizeof(info->fw_version) - 1);
+       strncpy(info->fw_version,
+               i2400m->fw_name ? : "", sizeof(info->fw_version) - 1);
        if (net_dev->dev.parent)
                strncpy(info->bus_info, dev_name(net_dev->dev.parent),
                        sizeof(info->bus_info) - 1);