package/kernel/mac80211/patches/subsys/314-mac80211-drop-data-frames-without-key-on-encrypted-l.patch

   1 From a0761a301746ec2d92d7fcb82af69c0a6a4339aa Mon Sep 17 00:00:00 2001
   2 From: Johannes Berg <johannes.berg@intel.com>
   3 Date: Thu, 26 Mar 2020 15:09:42 +0200
   4 Subject: mac80211: drop data frames without key on encrypted links
   5
   6 If we know that we have an encrypted link (based on having had
   7 a key configured for TX in the past) then drop all data frames
   8 in the key selection handler if there's no key anymore.
   9
  10 This fixes an issue with mac80211 internal TXQs - there we can
  11 buffer frames for an encrypted link, but then if the key is no
  12 longer there when they're dequeued, the frames are sent without
  13 encryption. This happens if a station is disconnected while the
  14 frames are still on the TXQ.
  15
  16 Detecting that a link should be encrypted based on a first key
  17 having been configured for TX is fine as there are no use cases
  18 for a connection going from with encryption to no encryption.
  19 With extended key IDs, however, there is a case of having a key
  20 configured for only decryption, so we can't just trigger this
  21 behaviour on a key being configured.
  22
  23 Cc: stable@vger.kernel.org
  24 Reported-by: Jouni Malinen <j@w1.fi>
  25 Signed-off-by: Johannes Berg <johannes.berg@intel.com>
  26 Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
  27 ---
  28  net/mac80211/debugfs_sta.c |  3 ++-
  29  net/mac80211/key.c         | 20 ++++++++++++--------
  30  net/mac80211/sta_info.h    |  1 +
  31  net/mac80211/tx.c          | 12 +++++++++---
  32  4 files changed, 24 insertions(+), 12 deletions(-)
  33
  34 --- a/net/mac80211/debugfs_sta.c
  35 +++ b/net/mac80211/debugfs_sta.c
  36 @@ -5,7 +5,7 @@
  37   * Copyright 2007      Johannes Berg <johannes@sipsolutions.net>
  38   * Copyright 2013-2014  Intel Mobile Communications GmbH
  39   * Copyright(c) 2016 Intel Deutschland GmbH
  40 - * Copyright (C) 2018 - 2019 Intel Corporation
  41 + * Copyright (C) 2018 - 2020 Intel Corporation
  42   */
  43
  44  #include <linux/debugfs.h>
  45 @@ -78,6 +78,7 @@ static const char * const sta_flag_names
  46         FLAG(MPSP_OWNER),
  47         FLAG(MPSP_RECIPIENT),
  48         FLAG(PS_DELIVER),
  49 +       FLAG(USES_ENCRYPTION),
  50  #undef FLAG
  51  };
  52
  53 --- a/net/mac80211/key.c
  54 +++ b/net/mac80211/key.c
  55 @@ -6,7 +6,7 @@
  56   * Copyright 2007-2008 Johannes Berg <johannes@sipsolutions.net>
  57   * Copyright 2013-2014  Intel Mobile Communications GmbH
  58   * Copyright 2015-2017 Intel Deutschland GmbH
  59 - * Copyright 2018-2019  Intel Corporation
  60 + * Copyright 2018-2020  Intel Corporation
  61   */
  62
  63  #include <linux/if_ether.h>
  64 @@ -262,22 +262,29 @@ static void ieee80211_key_disable_hw_acc
  65                           sta ? sta->sta.addr : bcast_addr, ret);
  66  }
  67
  68 -int ieee80211_set_tx_key(struct ieee80211_key *key)
  69 +static int _ieee80211_set_tx_key(struct ieee80211_key *key, bool force)
  70  {
  71         struct sta_info *sta = key->sta;
  72         struct ieee80211_local *local = key->local;
  73
  74         assert_key_lock(local);
  75
  76 +       set_sta_flag(sta, WLAN_STA_USES_ENCRYPTION);
  77 +
  78         sta->ptk_idx = key->conf.keyidx;
  79
  80 -       if (!ieee80211_hw_check(&local->hw, AMPDU_KEYBORDER_SUPPORT))
  81 +       if (force || !ieee80211_hw_check(&local->hw, AMPDU_KEYBORDER_SUPPORT))
  82                 clear_sta_flag(sta, WLAN_STA_BLOCK_BA);
  83         ieee80211_check_fast_xmit(sta);
  84
  85         return 0;
  86  }
  87
  88 +int ieee80211_set_tx_key(struct ieee80211_key *key)
  89 +{
  90 +       return _ieee80211_set_tx_key(key, false);
  91 +}
  92 +
  93  static void ieee80211_pairwise_rekey(struct ieee80211_key *old,
  94                                      struct ieee80211_key *new)
  95  {
  96 @@ -441,11 +448,8 @@ static int ieee80211_key_replace(struct
  97                 if (pairwise) {
  98                         rcu_assign_pointer(sta->ptk[idx], new);
  99                         if (new &&
 100 -                           !(new->conf.flags & IEEE80211_KEY_FLAG_NO_AUTO_TX)) {
 101 -                               sta->ptk_idx = idx;
 102 -                               clear_sta_flag(sta, WLAN_STA_BLOCK_BA);
 103 -                               ieee80211_check_fast_xmit(sta);
 104 -                       }
 105 +                           !(new->conf.flags & IEEE80211_KEY_FLAG_NO_AUTO_TX))
 106 +                               _ieee80211_set_tx_key(new, true);
 107                 } else {
 108                         rcu_assign_pointer(sta->gtk[idx], new);
 109                 }
 110 --- a/net/mac80211/sta_info.h
 111 +++ b/net/mac80211/sta_info.h
 112 @@ -98,6 +98,7 @@ enum ieee80211_sta_info_flags {
 113         WLAN_STA_MPSP_OWNER,
 114         WLAN_STA_MPSP_RECIPIENT,
 115         WLAN_STA_PS_DELIVER,
 116 +       WLAN_STA_USES_ENCRYPTION,
 117
 118         NUM_WLAN_STA_FLAGS,
 119  };
 120 --- a/net/mac80211/tx.c
 121 +++ b/net/mac80211/tx.c
 122 @@ -590,10 +590,13 @@ ieee80211_tx_h_select_key(struct ieee802
 123         struct ieee80211_tx_info *info = IEEE80211_SKB_CB(tx->skb);
 124         struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)tx->skb->data;
 125
 126 -       if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT))
 127 +       if (unlikely(info->flags & IEEE80211_TX_INTFL_DONT_ENCRYPT)) {
 128                 tx->key = NULL;
 129 -       else if (tx->sta &&
 130 -                (key = rcu_dereference(tx->sta->ptk[tx->sta->ptk_idx])))
 131 +               return TX_CONTINUE;
 132 +       }
 133 +
 134 +       if (tx->sta &&
 135 +           (key = rcu_dereference(tx->sta->ptk[tx->sta->ptk_idx])))
 136                 tx->key = key;
 137         else if (ieee80211_is_group_privacy_action(tx->skb) &&
 138                 (key = rcu_dereference(tx->sdata->default_multicast_key)))
 139 @@ -654,6 +657,9 @@ ieee80211_tx_h_select_key(struct ieee802
 140                 if (!skip_hw && tx->key &&
 141                     tx->key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)
 142                         info->control.hw_key = &tx->key->conf;
 143 +       } else if (!ieee80211_is_mgmt(hdr->frame_control) && tx->sta &&
 144 +                  test_sta_flag(tx->sta, WLAN_STA_USES_ENCRYPTION)) {
 145 +               return TX_DROP;
 146         }
 147
 148         return TX_CONTINUE;