cfg80211/mac80211: fix BSS leaks when abandoning assoc attempts

commit e6f462df9acd2a3295e5d34eb29e2823220cf129 upstream.

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.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/wireless/core.h b/net/wireless/core.h
index f0c0c8a..5f5867f 100644
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -410,6 +410,7 @@
 void cfg80211_sme_deauth(struct wireless_dev *wdev);
 void cfg80211_sme_auth_timeout(struct wireless_dev *wdev);
 void cfg80211_sme_assoc_timeout(struct wireless_dev *wdev);
+void cfg80211_sme_abandon_assoc(struct wireless_dev *wdev);
 
 /* internal helpers */
 bool cfg80211_supported_cipher_suite(struct wiphy *wiphy, u32 cipher);