commit bdd3ae3d1e749cf6597f035a5357f297a1af8eb3
author Johannes Berg <johannes.berg@intel.com> Mon Jan 02 13:30:03 2012 +0100
committer John W. Linville <linville@tuxdriver.com> Wed Jan 11 15:14:50 2012 -0500
tree 919de2a3adaf00d99c9d3b726c2a47a75026540f
parent 1a19f77f3642b8194ad9cf55548cc5d92e841766

nl80211: fix old station flags compatibility

My patch to validate station flags broke compatibility
with the old station flags setting where all flags are
always set at once since it always set the mask as all
possible flags which ended up being rejected later in
the station add/modify code.

Fix by parsing only the current flags in the old flags
attribute -- new applications and new flags should use
(and will now require) the new flags attribute where
the mask is given by the application.

Reported-and-tested-by: Thomas Hilber <ath9k-dev@toh.cx>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/wireless/nl80211.c

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index b3d3cf8..afeea32 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -2250,6 +2250,7 @@
 };
 
 static int parse_station_flags(struct genl_info *info,
+			       enum nl80211_iftype iftype,
 			       struct station_parameters *params)
 {
 	struct nlattr *flags[NL80211_STA_FLAG_MAX + 1];
@@ -2283,8 +2284,33 @@
 			     nla, sta_flags_policy))
 		return -EINVAL;
 
-	params->sta_flags_mask = (1 << __NL80211_STA_FLAG_AFTER_LAST) - 1;
-	params->sta_flags_mask &= ~1;
+	/*
+	 * Only allow certain flags for interface types so that
+	 * other attributes are silently ignored. Remember that
+	 * this is backward compatibility code with old userspace
+	 * and shouldn't be hit in other cases anyway.
+	 */
+	switch (iftype) {
+	case NL80211_IFTYPE_AP:
+	case NL80211_IFTYPE_AP_VLAN:
+	case NL80211_IFTYPE_P2P_GO:
+		params->sta_flags_mask = BIT(NL80211_STA_FLAG_AUTHORIZED) |
+					 BIT(NL80211_STA_FLAG_SHORT_PREAMBLE) |
+					 BIT(NL80211_STA_FLAG_WME) |
+					 BIT(NL80211_STA_FLAG_MFP);
+		break;
+	case NL80211_IFTYPE_P2P_CLIENT:
+	case NL80211_IFTYPE_STATION:
+		params->sta_flags_mask = BIT(NL80211_STA_FLAG_AUTHORIZED) |
+					 BIT(NL80211_STA_FLAG_TDLS_PEER);
+		break;
+	case NL80211_IFTYPE_MESH_POINT:
+		params->sta_flags_mask = BIT(NL80211_STA_FLAG_AUTHENTICATED) |
+					 BIT(NL80211_STA_FLAG_MFP) |
+					 BIT(NL80211_STA_FLAG_AUTHORIZED);
+	default:
+		return -EINVAL;
+	}
 
 	for (flag = 1; flag <= NL80211_STA_FLAG_MAX; flag++)
 		if (flags[flag])
@@ -2585,7 +2611,7 @@
 	if (!rdev->ops->change_station)
 		return -EOPNOTSUPP;
 
-	if (parse_station_flags(info, &params))
+	if (parse_station_flags(info, dev->ieee80211_ptr->iftype, &params))
 		return -EINVAL;
 
 	if (info->attrs[NL80211_ATTR_STA_PLINK_ACTION])
@@ -2731,7 +2757,7 @@
 	if (!rdev->ops->add_station)
 		return -EOPNOTSUPP;
 
-	if (parse_station_flags(info, &params))
+	if (parse_station_flags(info, dev->ieee80211_ptr->iftype, &params))
 		return -EINVAL;
 
 	switch (dev->ieee80211_ptr->iftype) {