[PATCH 4.4 07/72] cfg80211: check wiphy driver existence for drvinfo report

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>

[ Upstream commit bfb7bac3a8f47100ebe7961bd14e924c96e21ca7 ]

When preparing ethtool drvinfo, check if wiphy driver is defined
before dereferencing it. Driver may not exist, e.g. if wiphy is
attached to a virtual platform device.

Signed-off-by: Sergey Matyukevich <sergey.matyukevich.os@quantenna.com>
Link: https://lore.kernel.org/r/20200203105644.28875-1-sergey.matyukevich.os@quantenna.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/wireless/ethtool.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/wireless/ethtool.c b/net/wireless/ethtool.c
index e9e91298c70de..3cedf2c2b60bd 100644
--- a/net/wireless/ethtool.c
+++ b/net/wireless/ethtool.c
@@ -6,9 +6,13 @@
 void cfg80211_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	struct device *pdev = wiphy_dev(wdev->wiphy);
 
-	strlcpy(info->driver, wiphy_dev(wdev->wiphy)->driver->name,
-		sizeof(info->driver));
+	if (pdev->driver)
+		strlcpy(info->driver, pdev->driver->name,
+			sizeof(info->driver));
+	else
+		strlcpy(info->driver, "N/A", sizeof(info->driver));
 
 	strlcpy(info->version, init_utsname()->release, sizeof(info->version));
 
-- 
2.20.1