[ 24/48] mwifiex: fix wrong return values in add_virtual_intf() error cases

[Ben Hutchings]

3.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Bing Zhao <bzhao@xxxxxxxxxxx>

commit 858faa57dd9e2b91f3f870fbb1185982e42f5a2b upstream

backported for linux-3.2.y, linux-3.3.y, linux-3.4.y

add_virtual_intf() needs to return an ERR_PTR(), instead of NULL,
on errors, otherwise cfg80211 will crash.

Reported-by: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Signed-off-by: Bing Zhao <bzhao@xxxxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/net/wireless/mwifiex/cfg80211.c |   21 +++++++++------------
 1 files changed, 9 insertions(+), 12 deletions(-)

diff --git a/drivers/net/wireless/mwifiex/cfg80211.c b/drivers/net/wireless/mwifiex/cfg80211.c
index 6505038..baf6919 100644
--- a/drivers/net/wireless/mwifiex/cfg80211.c
+++ b/drivers/net/wireless/mwifiex/cfg80211.c
@@ -1214,11 +1214,11 @@ struct net_device *mwifiex_add_virtual_intf(struct wiphy *wiphy,
 	void *mdev_priv;
 
 	if (!priv)
-		return NULL;
+		return ERR_PTR(-EFAULT);
 
 	adapter = priv->adapter;
 	if (!adapter)
-		return NULL;
+		return ERR_PTR(-EFAULT);
 
 	switch (type) {
 	case NL80211_IFTYPE_UNSPECIFIED:
@@ -1227,7 +1227,7 @@ struct net_device *mwifiex_add_virtual_intf(struct wiphy *wiphy,
 		if (priv->bss_mode) {
 			wiphy_err(wiphy, "cannot create multiple"
 					" station/adhoc interfaces\n");
-			return NULL;
+			return ERR_PTR(-EINVAL);
 		}
 
 		if (type == NL80211_IFTYPE_UNSPECIFIED)
@@ -1244,14 +1244,15 @@ struct net_device *mwifiex_add_virtual_intf(struct wiphy *wiphy,
 		break;
 	default:
 		wiphy_err(wiphy, "type not supported\n");
-		return NULL;
+		return ERR_PTR(-EINVAL);
 	}
 
 	dev = alloc_netdev_mq(sizeof(struct mwifiex_private *), name,
 			      ether_setup, 1);
 	if (!dev) {
 		wiphy_err(wiphy, "no memory available for netdevice\n");
-		goto error;
+		priv->bss_mode = NL80211_IFTYPE_UNSPECIFIED;
+		return ERR_PTR(-ENOMEM);
 	}
 
 	dev_net_set(dev, wiphy_net(wiphy));
@@ -1276,7 +1277,9 @@ struct net_device *mwifiex_add_virtual_intf(struct wiphy *wiphy,
 	/* Register network device */
 	if (register_netdevice(dev)) {
 		wiphy_err(wiphy, "cannot register virtual network device\n");
-		goto error;
+		free_netdev(dev);
+		priv->bss_mode = NL80211_IFTYPE_UNSPECIFIED;
+		return ERR_PTR(-EFAULT);
 	}
 
 	sema_init(&priv->async_sem, 1);
@@ -1288,12 +1291,6 @@ struct net_device *mwifiex_add_virtual_intf(struct wiphy *wiphy,
 	mwifiex_dev_debugfs_init(priv);
 #endif
 	return dev;
-error:
-	if (dev && (dev->reg_state == NETREG_UNREGISTERED))
-		free_netdev(dev);
-	priv->bss_mode = NL80211_IFTYPE_UNSPECIFIED;
-
-	return NULL;
 }
 EXPORT_SYMBOL_GPL(mwifiex_add_virtual_intf);
 


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