Commit a0761a30 authored by Johannes Berg's avatar Johannes Berg

mac80211: drop data frames without key on encrypted links

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@vger.kernel.org
Reported-by: default avatarJouni Malinen <j@w1.fi>
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarLuca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200326150855.6865c7f28a14.I9fb1d911b064262d33e33dfba730cdeef83926ca@changeidSigned-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent 575a97ac
......@@ -5,7 +5,7 @@
* Copyright 2007 Johannes Berg <johannes@sipsolutions.net>
* 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
};
......
......@@ -6,7 +6,7 @@
* Copyright 2007-2008 Johannes Berg <johannes@sipsolutions.net>
* 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_accel(struct ieee80211_key *key)
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 ieee80211_sub_if_data *sdata,
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);
}
......
......@@ -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,
};
......
......@@ -590,10 +590,13 @@ ieee80211_tx_h_select_key(struct ieee80211_tx_data *tx)
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 ieee80211_tx_data *tx)
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;
......
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