cfg80211/mac80211: fix BSS leaks when abandoning assoc attempts

When mac80211 abandons an association attempt, it may free
all the data structures, but inform cfg80211 and userspace
about it only by sending the deauth frame it received, in
which case cfg80211 has no link to the BSS struct that was
used and will not cfg80211_unhold_bss() it.

Fix this by providing a way to inform cfg80211 of this with
the BSS entry passed, so that it can clean up properly, and
use this ability in the appropriate places in mac80211.

This isn't ideal: some code is more or less duplicated and
tracing is missing. However, it's a fairly small change and
it's thus easier to backport - cleanups can come later.

Cc: stable@vger.kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
index bd1f7a159d6a..4646cf5695b9 100644
--- a/net/wireless/mlme.c
+++ b/net/wireless/mlme.c
@@ -149,6 +149,18 @@ void cfg80211_assoc_timeout(struct net_device *dev, struct cfg80211_bss *bss)
 }
 EXPORT_SYMBOL(cfg80211_assoc_timeout);
 
+void cfg80211_abandon_assoc(struct net_device *dev, struct cfg80211_bss *bss)
+{
+	struct wireless_dev *wdev = dev->ieee80211_ptr;
+	struct wiphy *wiphy = wdev->wiphy;
+
+	cfg80211_sme_abandon_assoc(wdev);
+
+	cfg80211_unhold_bss(bss_from_pub(bss));
+	cfg80211_put_bss(wiphy, bss);
+}
+EXPORT_SYMBOL(cfg80211_abandon_assoc);
+
 void cfg80211_tx_mlme_mgmt(struct net_device *dev, const u8 *buf, size_t len)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;