diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 3cc1ca17a1a8..8c26d2d36cbe 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -2531,6 +2531,19 @@ void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb); * The set_default_unicast_key() call updates the default WEP key index * configured to the hardware for WEP encryption type. This is required * for devices that support offload of data packets (e.g. ARP responses). + * + * Mac80211 drivers should set the @NL80211_EXT_FEATURE_CAN_REPLACE_PTK0 flag + * when they are able to replace in-use PTK keys according to to following + * requirements: + * 1) They do not hand over frames decrypted with the old key to + mac80211 once the call to set_key() with command %DISABLE_KEY has been + completed when also setting @IEEE80211_KEY_FLAG_GENERATE_IV for any key, + 2) either drop or continue to use the old key for any outgoing frames queued + at the time of the key deletion (including re-transmits), + 3) never send out a frame queued prior to the set_key() %SET_KEY command + encrypted with the new key and + 4) never send out a frame unencrypted when it should be encrypted. + Mac80211 will not queue any new frames for a deleted key to the driver. */ /** diff --git a/net/mac80211/key.c b/net/mac80211/key.c index c054ac85793c..d6eeace7b83a 100644 --- a/net/mac80211/key.c +++ b/net/mac80211/key.c @@ -248,6 +248,7 @@ static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key) (key->conf.flags & IEEE80211_KEY_FLAG_RESERVE_TAILROOM))) increment_tailroom_need_count(sdata); + key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE; ret = drv_set_key(key->local, DISABLE_KEY, sdata, sta ? &sta->sta : NULL, &key->conf); @@ -256,8 +257,65 @@ static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key) "failed to remove key (%d, %pM) from hardware (%d)\n", key->conf.keyidx, sta ? sta->sta.addr : bcast_addr, ret); +} - key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE; +static int ieee80211_hw_key_replace(struct ieee80211_key *old_key, + struct ieee80211_key *new_key, + bool ptk0rekey) +{ + struct ieee80211_sub_if_data *sdata; + struct ieee80211_local *local; + struct sta_info *sta; + int ret; + + /* Aggregation sessions are OK when running on SW crypto. + * A broken remote STA may cause issues not observed with HW + * crypto, though. + */ + if (!(old_key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) + return 0; + + assert_key_lock(old_key->local); + sta = old_key->sta; + + /* PTK only using key ID 0 needs special handling on rekey */ + if (new_key && sta && ptk0rekey) { + local = old_key->local; + sdata = old_key->sdata; + + /* Stop TX till we are on the new key */ + old_key->flags |= KEY_FLAG_TAINTED; + ieee80211_clear_fast_xmit(sta); + + /* Aggregation sessions during rekey are complicated due to the + * reorder buffer and retransmits. Side step that by blocking + * aggregation during rekey and tear down running sessions. + */ + if (ieee80211_hw_check(&local->hw, AMPDU_AGGREGATION)) { + set_sta_flag(sta, WLAN_STA_BLOCK_BA); + ieee80211_sta_tear_down_BA_sessions(sta, + AGG_STOP_LOCAL_REQUEST); + } + + if (!wiphy_ext_feature_isset(local->hw.wiphy, + NL80211_EXT_FEATURE_CAN_REPLACE_PTK0)) { + pr_warn_ratelimited("Rekeying PTK for STA %pM but driver can't safely do that.", + sta->sta.addr); + /* Flushing the driver queues *may* help prevent + * the clear text leaks and freezes. + */ + ieee80211_flush_queues(local, sdata, false); + } + } + + ieee80211_key_disable_hw_accel(old_key); + + if (new_key) + ret = ieee80211_key_enable_hw_accel(new_key); + else + ret = 0; + + return ret; } static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, @@ -316,38 +374,56 @@ void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, } -static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata, +static int ieee80211_key_replace(struct ieee80211_sub_if_data *sdata, struct sta_info *sta, bool pairwise, struct ieee80211_key *old, struct ieee80211_key *new) { int idx; + int ret; bool defunikey, defmultikey, defmgmtkey; /* caller must provide at least one old/new */ if (WARN_ON(!new && !old)) - return; + return 0; if (new) list_add_tail_rcu(&new->list, &sdata->key_list); WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx); - if (old) + if (old) { idx = old->conf.keyidx; - else + /* TODO: proper implement and test "Extended Key ID for + * Individually Addressed Frames" from IEEE 802.11-2016. + * Till then always assume only key ID 0 is used for + * pairwise keys.*/ + ret = ieee80211_hw_key_replace(old, new, pairwise); + } else { idx = new->conf.keyidx; + if (new && !new->local->wowlan) + ret = ieee80211_key_enable_hw_accel(new); + else + ret = 0; + } + + if (ret) + return ret; if (sta) { if (pairwise) { rcu_assign_pointer(sta->ptk[idx], new); sta->ptk_idx = idx; - ieee80211_check_fast_xmit(sta); + if (new) { + clear_sta_flag(sta, WLAN_STA_BLOCK_BA); + ieee80211_check_fast_xmit(sta); + } } else { rcu_assign_pointer(sta->gtk[idx], new); } - ieee80211_check_fast_rx(sta); + if (new) + ieee80211_check_fast_rx(sta); } else { defunikey = old && old == key_mtx_dereference(sdata->local, @@ -380,6 +456,8 @@ static void ieee80211_key_replace(struct ieee80211_sub_if_data *sdata, if (old) list_del_rcu(&old->list); + + return 0; } struct ieee80211_key * @@ -575,9 +653,6 @@ static void ieee80211_key_free_common(struct ieee80211_key *key) static void __ieee80211_key_destroy(struct ieee80211_key *key, bool delay_tailroom) { - if (key->local) - ieee80211_key_disable_hw_accel(key); - if (key->local) { struct ieee80211_sub_if_data *sdata = key->sdata; @@ -654,7 +729,6 @@ int ieee80211_key_link(struct ieee80211_key *key, struct ieee80211_sub_if_data *sdata, struct sta_info *sta) { - struct ieee80211_local *local = sdata->local; struct ieee80211_key *old_key; int idx = key->conf.keyidx; bool pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE; @@ -691,17 +765,13 @@ int ieee80211_key_link(struct ieee80211_key *key, increment_tailroom_need_count(sdata); - ieee80211_key_replace(sdata, sta, pairwise, old_key, key); - ieee80211_key_destroy(old_key, delay_tailroom); + ret = ieee80211_key_replace(sdata, sta, pairwise, old_key, key); - ieee80211_debugfs_key_add(key); - - if (!local->wowlan) { - ret = ieee80211_key_enable_hw_accel(key); - if (ret) - ieee80211_key_free(key, delay_tailroom); + if (!ret) { + ieee80211_debugfs_key_add(key); + ieee80211_key_destroy(old_key, delay_tailroom); } else { - ret = 0; + ieee80211_key_free(key, delay_tailroom); } out: diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c index 7d34222337c0..e88547842239 100644 --- a/net/mac80211/tx.c +++ b/net/mac80211/tx.c @@ -2968,6 +2968,10 @@ void ieee80211_check_fast_xmit(struct sta_info *sta) if (!(build.key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE)) goto out; + /* Key is being removed */ + if (build.key->flags & KEY_FLAG_TAINTED) + goto out; + switch (build.key->conf.cipher) { case WLAN_CIPHER_SUITE_CCMP: case WLAN_CIPHER_SUITE_CCMP_256: