From: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
We first want to flush the station to make sure we no longer have any
frames being Tx by the station before the station is moved to
un-authorized state. Failing to do that will lead to races: a frame may
be sent after the station's state has been changed.
Since the API clearly states that the driver can't fail the sta_state()
transition down the list of state, we can easily flush the station
first, and only then call the driver's sta_state().
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@xxxxxxxxx>
Reviewed-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@xxxxxxxxx>
---
net/mac80211/sta_info.c | 20 +++++++++++++++++---
1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index f83268fa9f92..caa3d0236b5e 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -4,7 +4,7 @@
* Copyright 2006-2007 Jiri Benc <jbenc@xxxxxxx>
* Copyright 2013-2014 Intel Mobile Communications GmbH
* Copyright (C) 2015 - 2017 Intel Deutschland GmbH
- * Copyright (C) 2018-2023 Intel Corporation
+ * Copyright (C) 2018-2024 Intel Corporation
*/
#include <linux/module.h>
@@ -1335,9 +1335,13 @@ static int _sta_info_move_state(struct sta_info *sta,
sta->sta.addr, new_state);
/* notify the driver before the actual changes so it can
- * fail the transition
+ * fail the transition if the state is increasing.
+ * The driver is required not to fail when the transition
+ * is decreasing the state, so first, do all the preparation
+ * work and only then, notify the driver.
*/
- if (test_sta_flag(sta, WLAN_STA_INSERTED)) {
+ if (new_state > sta->sta_state &&
+ test_sta_flag(sta, WLAN_STA_INSERTED)) {
int err = drv_sta_state(sta->local, sta->sdata, sta,
sta->sta_state, new_state);
if (err)
@@ -1413,6 +1417,16 @@ static int _sta_info_move_state(struct sta_info *sta,
break;
}
+ if (new_state < sta->sta_state &&
+ test_sta_flag(sta, WLAN_STA_INSERTED)) {
+ int err = drv_sta_state(sta->local, sta->sdata, sta,
+ sta->sta_state, new_state);
+
+ WARN_ONCE(err,
+ "Driver is not allowed to fail if the sta_state is transitioning down the list: %d\n",
+ err);
+ }
+
sta->sta_state = new_state;
return 0;
--
2.34.1
