+From 4db561ae4a90c2d0e15996634567559e292dc9e5 Mon Sep 17 00:00:00 2001
+From: Ahmed Zaki <anzaki@gmail.com>
+Date: Sat, 2 Oct 2021 08:53:29 -0600
+Subject: [PATCH] mac80211: fix a memory leak where sta_info is not freed
+
+commit 8f9dcc29566626f683843ccac6113a12208315ca upstream.
+
+The following is from a system that went OOM due to a memory leak:
+
+wlan0: Allocated STA 74:83:c2:64:0b:87
+wlan0: Allocated STA 74:83:c2:64:0b:87
+wlan0: IBSS finish 74:83:c2:64:0b:87 (---from ieee80211_ibss_add_sta)
+wlan0: Adding new IBSS station 74:83:c2:64:0b:87
+wlan0: moving STA 74:83:c2:64:0b:87 to state 2
+wlan0: moving STA 74:83:c2:64:0b:87 to state 3
+wlan0: Inserted STA 74:83:c2:64:0b:87
+wlan0: IBSS finish 74:83:c2:64:0b:87 (---from ieee80211_ibss_work)
+wlan0: Adding new IBSS station 74:83:c2:64:0b:87
+wlan0: moving STA 74:83:c2:64:0b:87 to state 2
+wlan0: moving STA 74:83:c2:64:0b:87 to state 3
+.
+.
+wlan0: expiring inactive not authorized STA 74:83:c2:64:0b:87
+wlan0: moving STA 74:83:c2:64:0b:87 to state 2
+wlan0: moving STA 74:83:c2:64:0b:87 to state 1
+wlan0: Removed STA 74:83:c2:64:0b:87
+wlan0: Destroyed STA 74:83:c2:64:0b:87
+
+The ieee80211_ibss_finish_sta() is called twice on the same STA from 2
+different locations. On the second attempt, the allocated STA is not
+destroyed creating a kernel memory leak.
+
+This is happening because sta_info_insert_finish() does not call
+sta_info_free() the second time when the STA already exists (returns
+-EEXIST). Note that the caller sta_info_insert_rcu() assumes STA is
+destroyed upon errors.
+
+Same fix is applied to -ENOMEM.
+
+Signed-off-by: Ahmed Zaki <anzaki@gmail.com>
+Link: https://lore.kernel.org/r/20211002145329.3125293-1-anzaki@gmail.com
+[change the error path label to use the existing code]
+Signed-off-by: Johannes Berg <johannes.berg@intel.com>
+Signed-off-by: Viacheslav Sablin <sablin@ispras.ru>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ net/mac80211/sta_info.c | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+--- a/net/mac80211/sta_info.c
++++ b/net/mac80211/sta_info.c
+@@ -646,13 +646,13 @@ static int sta_info_insert_finish(struct
+ /* check if STA exists already */
+ if (sta_info_get_bss(sdata, sta->sta.addr)) {
+ err = -EEXIST;
+- goto out_err;
++ goto out_cleanup;
+ }
+
+ sinfo = kzalloc(sizeof(struct station_info), GFP_KERNEL);
+ if (!sinfo) {
+ err = -ENOMEM;
+- goto out_err;
++ goto out_cleanup;
+ }
+
+ local->num_sta++;
+@@ -708,8 +708,8 @@ static int sta_info_insert_finish(struct
+ out_drop_sta:
+ local->num_sta--;
+ synchronize_net();
++ out_cleanup:
+ cleanup_single_sta(sta);
+- out_err:
+ mutex_unlock(&local->sta_mtx);
+ kfree(sinfo);
+ rcu_read_lock();