This is a note to let you know that I've just added the patch titled mac80211: always wind down STA state to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mac80211-always-wind-down-sta-state.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 6e9e508939e98e0864159eae78ff372104b75a62 Author: Johannes Berg <johannes.berg@xxxxxxxxx> Date: Fri Oct 9 14:17:11 2020 +0200 mac80211: always wind down STA state [ Upstream commit dcd479e10a0510522a5d88b29b8f79ea3467d501 ] When (for example) an IBSS station is pre-moved to AUTHORIZED before it's inserted, and then the insertion fails, we don't clean up the fast RX/TX states that might already have been created, since we don't go through all the state transitions again on the way down. Do that, if it hasn't been done already, when the station is freed. I considered only freeing the fast TX/RX state there, but we might add more state so it's more robust to wind down the state properly. Note that we warn if the station was ever inserted, it should have been properly cleaned up in that case, and the driver will probably not like things happening out of order. Reported-by: syzbot+2e293dbd67de2836ba42@xxxxxxxxxxxxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20201009141710.7223b322a955.I95bd08b9ad0e039c034927cce0b75beea38e059b@changeid Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index fef8d7758dae9..8a9bbcfefbca6 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -243,6 +243,24 @@ struct sta_info *sta_info_get_by_idx(struct ieee80211_sub_if_data *sdata, */ void sta_info_free(struct ieee80211_local *local, struct sta_info *sta) { + /* + * If we had used sta_info_pre_move_state() then we might not + * have gone through the state transitions down again, so do + * it here now (and warn if it's inserted). + * + * This will clear state such as fast TX/RX that may have been + * allocated during state transitions. + */ + while (sta->sta_state > IEEE80211_STA_NONE) { + int ret; + + WARN_ON_ONCE(test_sta_flag(sta, WLAN_STA_INSERTED)); + + ret = sta_info_move_state(sta, sta->sta_state - 1); + if (WARN_ONCE(ret, "sta_info_move_state() returned %d\n", ret)) + break; + } + if (sta->rate_ctrl) rate_control_free_sta(sta);