From: Johannes Berg <johannes.berg@xxxxxxxxx> commit a0761a301746ec2d92d7fcb82af69c0a6a4339aa upstream. If we know that we have an encrypted link (based on having had a key configured for TX in the past) then drop all data frames in the key selection handler if there's no key anymore. This fixes an issue with mac80211 internal TXQs - there we can buffer frames for an encrypted link, but then if the key is no longer there when they're dequeued, the frames are sent without encryption. This happens if a station is disconnected while the frames are still on the TXQ. Detecting that a link should be encrypted based on a first key having been configured for TX is fine as there are no use cases for a connection going from with encryption to no encryption. With extended key IDs, however, there is a case of having a key configured for only decryption, so we can't just trigger this behaviour on a key being configured. Cc: stable@xxxxxxxxxxxxxxx Reported-by: Jouni Malinen <j@xxxxx> Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx> Link: https://lore.kernel.org/r/iwlwifi.20200326150855.6865c7f28a14.I9fb1d911b064262d33e33dfba730cdeef83926ca@changeid Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/mac80211/debugfs_sta.c | 3 ++- net/mac80211/key.c | 20 ++++++++++++-------- net/mac80211/sta_info.h | 1 + net/mac80211/tx.c | 12 +++++++++--- 4 files changed, 24 insertions(+), 12 deletions(-) --- a/net/mac80211/debugfs_sta.c +++ b/net/mac80211/debugfs_sta.c @@ -5,7 +5,7 @@ * Copyright 2007 Johannes Berg <johannes@xxxxxxxxxxxxxxxx> * Copyright 2013-2014 Intel Mobile Communications GmbH * Copyright(c) 2016 Intel Deutschland GmbH - * Copyright (C) 2018 - 2019 Intel Corporation + * Copyright (C) 2018 - 2020 Intel Corporation */ #include <linux/debugfs.h> @@ -78,6 +78,7 @@ static const char * const sta_flag_names FLAG(MPSP_OWNER), FLAG(MPSP_RECIPIENT), FLAG(PS_DELIVER), + FLAG(USES_ENCRYPTION), #undef FLAG }; --- a/net/mac80211/key.c +++ b/net/mac80211/key.c @@ -6,7 +6,7 @@ * Copyright 2007-2008 Johannes Berg <johannes@xxxxxxxxxxxxxxxx> * Copyright 2013-2014 Intel Mobile Communications GmbH * Copyright 2015-2017 Intel Deutschland GmbH - * Copyright 2018-2019 Intel Corporation + * Copyright 2018-2020 Intel Corporation */ #include <linux/if_ether.h> @@ -262,22 +262,29 @@ static void ieee80211_key_disable_hw_acc sta ? sta->sta.addr : bcast_addr, ret); } -int ieee80211_set_tx_key(struct ieee80211_key *key) +static int _ieee80211_set_tx_key(struct ieee80211_key *key, bool force) { struct sta_info *sta = key->sta; struct ieee80211_local *local = key->local; assert_key_lock(local); + set_sta_flag(sta, WLAN_STA_USES_ENCRYPTION); + sta->ptk_idx = key->conf.keyidx; - if (!ieee80211_hw_check(&local->hw, AMPDU_KEYBORDER_SUPPORT)) + if (force || !ieee80211_hw_check(&local->hw, AMPDU_KEYBORDER_SUPPORT)) clear_sta_flag(sta, WLAN_STA_BLOCK_BA); ieee80211_check_fast_xmit(sta); return 0; } +int ieee80211_set_tx_key(struct ieee80211_key *key) +{ + return _ieee80211_set_tx_key(key, false); +} + static void ieee80211_pairwise_rekey(struct ieee80211_key *old, struct ieee80211_key *new) { @@ -441,11 +448,8 @@ static int ieee80211_key_replace(struct if (pairwise) { rcu_assign_pointer(sta->ptk[idx], new); if (new && - !(new->conf.flags & IEEE80211_KEY_FLAG_NO_AUTO_TX)) { - sta->ptk_idx = idx; - clear_sta_flag(sta, WLAN_STA_BLOCK_BA); - ieee80211_check_fast_xmit(sta); - } + !(new->conf.flags & IEEE80211_KEY_FLAG_NO_AUTO_TX)) + _ieee80211_set_tx_key(new, true); } else { rcu_assign_pointer(sta->gtk[idx], new); } --- a/net/mac80211/sta_info.h +++ b/net/mac80211/sta_info.h @@ -98,6 +98,7 @@ enum ieee80211_sta_info_flags { WLAN_STA_MPSP_OWNER, WLAN_STA_MPSP_RECIPIENT, WLAN_STA_PS_DELIVER, + WLAN_STA_USES_ENCRYPTION, NUM_WLAN_STA_FLAGS, }; --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -590,10 +590,13 @@ ieee80211_tx_h_select_key(struct ieee802 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb); struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data; - if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT)) + if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT)) { tx->key = NULL; - else if (tx->sta && - (key = rcu_dereference(tx->sta->ptk[tx->sta->ptk_idx]))) + return TX_CONTINUE; + } + + if (tx->sta && + (key = rcu_dereference(tx->sta->ptk[tx->sta->ptk_idx]))) tx->key = key; else if (ieee80211_is_group_privacy_action(tx->skb) && (key = rcu_dereference(tx->sdata->default_multicast_key))) @@ -654,6 +657,9 @@ ieee80211_tx_h_select_key(struct ieee802 if (!skip_hw && tx->key && tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) info->control.hw_key = &tx->key->conf; + } else if (!ieee80211_is_mgmt(hdr->frame_control) && tx->sta && + test_sta_flag(tx->sta, WLAN_STA_USES_ENCRYPTION)) { + return TX_DROP; } return TX_CONTINUE;
