[PATCH] nl80211: check channel switch validity better

[Johannes Berg <johannes@sipsolutions.net>]

From: Johannes Berg <johannes.berg@intel.com>

Before allowing userspace to initiate a channel switch, check
that it's actually connected in some sense. Also use a more
appropriate error code for the not connected case.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/wireless/nl80211.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 6e78c62..0c2ef08 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -5799,10 +5799,15 @@ static int nl80211_channel_switch(struct sk_buff *skb, struct genl_info *info)
 
 		/* useless if AP is not running */
 		if (!wdev->beacon_interval)
-			return -EINVAL;
+			return -ENOTCONN;
 		break;
 	case NL80211_IFTYPE_ADHOC:
+		if (!wdev->ssid_len)
+			return -ENOTCONN;
+		break;
 	case NL80211_IFTYPE_MESH_POINT:
+		if (!wdev->mesh_id_len)
+			return -ENOTCONN;
 		break;
 	default:
 		return -EOPNOTSUPP;
-- 
1.8.5.1