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tmp_suning_uos_patched/net/mac80211/key.c
Mathy Vanhoef 42d98e0219 mac80211: prevent mixed key and fragment cache attacks 
commit 94034c40ab4a3fcf581fbc7f8fdf4e29943c4a24 upstream.

Simultaneously prevent mixed key attacks (CVE-2020-24587) and fragment
cache attacks (CVE-2020-24586). This is accomplished by assigning a
unique color to every key (per interface) and using this to track which
key was used to decrypt a fragment. When reassembling frames, it is
now checked whether all fragments were decrypted using the same key.

To assure that fragment cache attacks are also prevented, the ID that is
assigned to keys is unique even over (re)associations and (re)connects.
This means fragments separated by a (re)association or (re)connect will
not be reassembled. Because mac80211 now also prevents the reassembly of
mixed encrypted and plaintext fragments, all cache attacks are prevented.

Cc: stable@vger.kernel.org
Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>
Link: https://lore.kernel.org/r/20210511200110.3f8290e59823.I622a67769ed39257327a362cfc09c812320eb979@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-03 09:00:29 +02:00

1310 lines
36 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2002-2005, Instant802 Networks, Inc.
* Copyright 2005-2006, Devicescape Software, Inc.
* Copyright 2006-2007 Jiri Benc <jbenc@suse.cz>
* Copyright 2007-2008 Johannes Berg <johannes@sipsolutions.net>
* Copyright 2013-2014 Intel Mobile Communications GmbH
* Copyright 2015-2017 Intel Deutschland GmbH
* Copyright 2018-2020 Intel Corporation
*/
#include <linux/if_ether.h>
#include <linux/etherdevice.h>
#include <linux/list.h>
#include <linux/rcupdate.h>
#include <linux/rtnetlink.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <net/mac80211.h>
#include <crypto/algapi.h>
#include <asm/unaligned.h>
#include "ieee80211_i.h"
#include "driver-ops.h"
#include "debugfs_key.h"
#include "aes_ccm.h"
#include "aes_cmac.h"
#include "aes_gmac.h"
#include "aes_gcm.h"
/**
* DOC: Key handling basics
*
* Key handling in mac80211 is done based on per-interface (sub_if_data)
* keys and per-station keys. Since each station belongs to an interface,
* each station key also belongs to that interface.
*
* Hardware acceleration is done on a best-effort basis for algorithms
* that are implemented in software, for each key the hardware is asked
* to enable that key for offloading but if it cannot do that the key is
* simply kept for software encryption (unless it is for an algorithm
* that isn't implemented in software).
* There is currently no way of knowing whether a key is handled in SW
* or HW except by looking into debugfs.
*
* All key management is internally protected by a mutex. Within all
* other parts of mac80211, key references are, just as STA structure
* references, protected by RCU. Note, however, that some things are
* unprotected, namely the key->sta dereferences within the hardware
* acceleration functions. This means that sta_info_destroy() must
* remove the key which waits for an RCU grace period.
*/
static const u8 bcast_addr[ETH_ALEN] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
static void assert_key_lock(struct ieee80211_local *local)
{
lockdep_assert_held(&local->key_mtx);
}
static void
update_vlan_tailroom_need_count(struct ieee80211_sub_if_data *sdata, int delta)
{
struct ieee80211_sub_if_data *vlan;
if (sdata->vif.type != NL80211_IFTYPE_AP)
return;
/* crypto_tx_tailroom_needed_cnt is protected by this */
assert_key_lock(sdata->local);
rcu_read_lock();
list_for_each_entry_rcu(vlan, &sdata->u.ap.vlans, u.vlan.list)
vlan->crypto_tx_tailroom_needed_cnt += delta;
rcu_read_unlock();
}
static void increment_tailroom_need_count(struct ieee80211_sub_if_data *sdata)
{
/*
* When this count is zero, SKB resizing for allocating tailroom
* for IV or MMIC is skipped. But, this check has created two race
* cases in xmit path while transiting from zero count to one:
*
* 1. SKB resize was skipped because no key was added but just before
* the xmit key is added and SW encryption kicks off.
*
* 2. SKB resize was skipped because all the keys were hw planted but
* just before xmit one of the key is deleted and SW encryption kicks
* off.
*
* In both the above case SW encryption will find not enough space for
* tailroom and exits with WARN_ON. (See WARN_ONs at wpa.c)
*
* Solution has been explained at
* http://mid.gmane.org/1308590980.4322.19.camel@jlt3.sipsolutions.net
*/
assert_key_lock(sdata->local);
update_vlan_tailroom_need_count(sdata, 1);
if (!sdata->crypto_tx_tailroom_needed_cnt++) {
/*
* Flush all XMIT packets currently using HW encryption or no
* encryption at all if the count transition is from 0 -> 1.
*/
synchronize_net();
}
}
static void decrease_tailroom_need_count(struct ieee80211_sub_if_data *sdata,
int delta)
{
assert_key_lock(sdata->local);
WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt < delta);
update_vlan_tailroom_need_count(sdata, -delta);
sdata->crypto_tx_tailroom_needed_cnt -= delta;
}
static int ieee80211_key_enable_hw_accel(struct ieee80211_key *key)
{
struct ieee80211_sub_if_data *sdata = key->sdata;
struct sta_info *sta;
int ret = -EOPNOTSUPP;
might_sleep();
if (key->flags & KEY_FLAG_TAINTED) {
/* If we get here, it's during resume and the key is
* tainted so shouldn't be used/programmed any more.
* However, its flags may still indicate that it was
* programmed into the device (since we're in resume)
* so clear that flag now to avoid trying to remove
* it again later.
*/
if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE &&
!(key->conf.flags & (IEEE80211_KEY_FLAG_GENERATE_MMIC |
IEEE80211_KEY_FLAG_PUT_MIC_SPACE |
IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
increment_tailroom_need_count(sdata);
key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
return -EINVAL;
}
if (!key->local->ops->set_key)
goto out_unsupported;
assert_key_lock(key->local);
sta = key->sta;
/*
* If this is a per-STA GTK, check if it
* is supported; if not, return.
*/
if (sta && !(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE) &&
!ieee80211_hw_check(&key->local->hw, SUPPORTS_PER_STA_GTK))
goto out_unsupported;
if (sta && !sta->uploaded)
goto out_unsupported;
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
/*
* The driver doesn't know anything about VLAN interfaces.
* Hence, don't send GTKs for VLAN interfaces to the driver.
*/
if (!(key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
ret = 1;
goto out_unsupported;
}
}
ret = drv_set_key(key->local, SET_KEY, sdata,
sta ? &sta->sta : NULL, &key->conf);
if (!ret) {
key->flags |= KEY_FLAG_UPLOADED_TO_HARDWARE;
if (!(key->conf.flags & (IEEE80211_KEY_FLAG_GENERATE_MMIC |
IEEE80211_KEY_FLAG_PUT_MIC_SPACE |
IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
decrease_tailroom_need_count(sdata, 1);
WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_IV_SPACE) &&
(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_IV));
WARN_ON((key->conf.flags & IEEE80211_KEY_FLAG_PUT_MIC_SPACE) &&
(key->conf.flags & IEEE80211_KEY_FLAG_GENERATE_MMIC));
return 0;
}
if (ret != -ENOSPC && ret != -EOPNOTSUPP && ret != 1)
sdata_err(sdata,
"failed to set key (%d, %pM) to hardware (%d)\n",
key->conf.keyidx,
sta ? sta->sta.addr : bcast_addr, ret);
out_unsupported:
switch (key->conf.cipher) {
case WLAN_CIPHER_SUITE_WEP40:
case WLAN_CIPHER_SUITE_WEP104:
case WLAN_CIPHER_SUITE_TKIP:
case WLAN_CIPHER_SUITE_CCMP:
case WLAN_CIPHER_SUITE_CCMP_256:
case WLAN_CIPHER_SUITE_GCMP:
case WLAN_CIPHER_SUITE_GCMP_256:
case WLAN_CIPHER_SUITE_AES_CMAC:
case WLAN_CIPHER_SUITE_BIP_CMAC_256:
case WLAN_CIPHER_SUITE_BIP_GMAC_128:
case WLAN_CIPHER_SUITE_BIP_GMAC_256:
/* all of these we can do in software - if driver can */
if (ret == 1)
return 0;
if (ieee80211_hw_check(&key->local->hw, SW_CRYPTO_CONTROL))
return -EINVAL;
return 0;
default:
return -EINVAL;
}
}
static void ieee80211_key_disable_hw_accel(struct ieee80211_key *key)
{
struct ieee80211_sub_if_data *sdata;
struct sta_info *sta;
int ret;
might_sleep();
if (!key || !key->local->ops->set_key)
return;
assert_key_lock(key->local);
if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
return;
sta = key->sta;
sdata = key->sdata;
if (!(key->conf.flags & (IEEE80211_KEY_FLAG_GENERATE_MMIC |
IEEE80211_KEY_FLAG_PUT_MIC_SPACE |
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);
if (ret)
sdata_err(sdata,
"failed to remove key (%d, %pM) from hardware (%d)\n",
key->conf.keyidx,
sta ? sta->sta.addr : bcast_addr, ret);
}
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 (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)
{
struct ieee80211_local *local = new->local;
struct sta_info *sta = new->sta;
int i;
assert_key_lock(local);
if (new->conf.flags & IEEE80211_KEY_FLAG_NO_AUTO_TX) {
/* Extended Key ID key install, initial one or rekey */
if (sta->ptk_idx != INVALID_PTK_KEYIDX &&
!ieee80211_hw_check(&local->hw, AMPDU_KEYBORDER_SUPPORT)) {
/* Aggregation Sessions with Extended Key ID must not
* mix MPDUs with different keyIDs within one A-MPDU.
* Tear down running Tx aggregation sessions and block
* new Rx/Tx aggregation requests during rekey to
* ensure there are no A-MPDUs when the driver is not
* supporting A-MPDU key borders. (Blocking Tx only
* would be sufficient but WLAN_STA_BLOCK_BA gets the
* job done for the few ms we need it.)
*/
set_sta_flag(sta, WLAN_STA_BLOCK_BA);
mutex_lock(&sta->ampdu_mlme.mtx);
for (i = 0; i < IEEE80211_NUM_TIDS; i++)
___ieee80211_stop_tx_ba_session(sta, i,
AGG_STOP_LOCAL_REQUEST);
mutex_unlock(&sta->ampdu_mlme.mtx);
}
} else if (old) {
/* Rekey without Extended Key ID.
* Aggregation sessions are OK when running on SW crypto.
* A broken remote STA may cause issues not observed with HW
* crypto, though.
*/
if (!(old->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
return;
/* Stop Tx till we are on the new key */
old->flags |= KEY_FLAG_TAINTED;
ieee80211_clear_fast_xmit(sta);
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, old->sdata, false);
}
}
}
static void __ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata,
int idx, bool uni, bool multi)
{
struct ieee80211_key *key = NULL;
assert_key_lock(sdata->local);
if (idx >= 0 && idx < NUM_DEFAULT_KEYS)
key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
if (uni) {
rcu_assign_pointer(sdata->default_unicast_key, key);
ieee80211_check_fast_xmit_iface(sdata);
if (sdata->vif.type != NL80211_IFTYPE_AP_VLAN)
drv_set_default_unicast_key(sdata->local, sdata, idx);
}
if (multi)
rcu_assign_pointer(sdata->default_multicast_key, key);
ieee80211_debugfs_key_update_default(sdata);
}
void ieee80211_set_default_key(struct ieee80211_sub_if_data *sdata, int idx,
bool uni, bool multi)
{
mutex_lock(&sdata->local->key_mtx);
__ieee80211_set_default_key(sdata, idx, uni, multi);
mutex_unlock(&sdata->local->key_mtx);
}
static void
__ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata, int idx)
{
struct ieee80211_key *key = NULL;
assert_key_lock(sdata->local);
if (idx >= NUM_DEFAULT_KEYS &&
idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS)
key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
rcu_assign_pointer(sdata->default_mgmt_key, key);
ieee80211_debugfs_key_update_default(sdata);
}
void ieee80211_set_default_mgmt_key(struct ieee80211_sub_if_data *sdata,
int idx)
{
mutex_lock(&sdata->local->key_mtx);
__ieee80211_set_default_mgmt_key(sdata, idx);
mutex_unlock(&sdata->local->key_mtx);
}
static void
__ieee80211_set_default_beacon_key(struct ieee80211_sub_if_data *sdata, int idx)
{
struct ieee80211_key *key = NULL;
assert_key_lock(sdata->local);
if (idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS &&
idx < NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS +
NUM_DEFAULT_BEACON_KEYS)
key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
rcu_assign_pointer(sdata->default_beacon_key, key);
ieee80211_debugfs_key_update_default(sdata);
}
void ieee80211_set_default_beacon_key(struct ieee80211_sub_if_data *sdata,
int idx)
{
mutex_lock(&sdata->local->key_mtx);
__ieee80211_set_default_beacon_key(sdata, idx);
mutex_unlock(&sdata->local->key_mtx);
}
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 = 0;
bool defunikey, defmultikey, defmgmtkey, defbeaconkey;
/* caller must provide at least one old/new */
if (WARN_ON(!new && !old))
return 0;
if (new)
list_add_tail_rcu(&new->list, &sdata->key_list);
WARN_ON(new && old && new->conf.keyidx != old->conf.keyidx);
if (new && sta && pairwise) {
/* Unicast rekey needs special handling. With Extended Key ID
* old is still NULL for the first rekey.
*/
ieee80211_pairwise_rekey(old, new);
}
if (old) {
idx = old->conf.keyidx;
if (old->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
ieee80211_key_disable_hw_accel(old);
if (new)
ret = ieee80211_key_enable_hw_accel(new);
}
} else {
/* new must be provided in case old is not */
idx = new->conf.keyidx;
if (!new->local->wowlan)
ret = ieee80211_key_enable_hw_accel(new);
}
if (ret)
return ret;
if (sta) {
if (pairwise) {
rcu_assign_pointer(sta->ptk[idx], new);
if (new &&
!(new->conf.flags & IEEE80211_KEY_FLAG_NO_AUTO_TX))
_ieee80211_set_tx_key(new, true);
} else {
rcu_assign_pointer(sta->gtk[idx], new);
}
/* Only needed for transition from no key -> key.
* Still triggers unnecessary when using Extended Key ID
* and installing the second key ID the first time.
*/
if (new && !old)
ieee80211_check_fast_rx(sta);
} else {
defunikey = old &&
old == key_mtx_dereference(sdata->local,
sdata->default_unicast_key);
defmultikey = old &&
old == key_mtx_dereference(sdata->local,
sdata->default_multicast_key);
defmgmtkey = old &&
old == key_mtx_dereference(sdata->local,
sdata->default_mgmt_key);
defbeaconkey = old &&
old == key_mtx_dereference(sdata->local,
sdata->default_beacon_key);
if (defunikey && !new)
__ieee80211_set_default_key(sdata, -1, true, false);
if (defmultikey && !new)
__ieee80211_set_default_key(sdata, -1, false, true);
if (defmgmtkey && !new)
__ieee80211_set_default_mgmt_key(sdata, -1);
if (defbeaconkey && !new)
__ieee80211_set_default_beacon_key(sdata, -1);
rcu_assign_pointer(sdata->keys[idx], new);
if (defunikey && new)
__ieee80211_set_default_key(sdata, new->conf.keyidx,
true, false);
if (defmultikey && new)
__ieee80211_set_default_key(sdata, new->conf.keyidx,
false, true);
if (defmgmtkey && new)
__ieee80211_set_default_mgmt_key(sdata,
new->conf.keyidx);
if (defbeaconkey && new)
__ieee80211_set_default_beacon_key(sdata,
new->conf.keyidx);
}
if (old)
list_del_rcu(&old->list);
return 0;
}
struct ieee80211_key *
ieee80211_key_alloc(u32 cipher, int idx, size_t key_len,
const u8 *key_data,
size_t seq_len, const u8 *seq,
const struct ieee80211_cipher_scheme *cs)
{
struct ieee80211_key *key;
int i, j, err;
if (WARN_ON(idx < 0 ||
idx >= NUM_DEFAULT_KEYS + NUM_DEFAULT_MGMT_KEYS +
NUM_DEFAULT_BEACON_KEYS))
return ERR_PTR(-EINVAL);
key = kzalloc(sizeof(struct ieee80211_key) + key_len, GFP_KERNEL);
if (!key)
return ERR_PTR(-ENOMEM);
/*
* Default to software encryption; we'll later upload the
* key to the hardware if possible.
*/
key->conf.flags = 0;
key->flags = 0;
key->conf.cipher = cipher;
key->conf.keyidx = idx;
key->conf.keylen = key_len;
switch (cipher) {
case WLAN_CIPHER_SUITE_WEP40:
case WLAN_CIPHER_SUITE_WEP104:
key->conf.iv_len = IEEE80211_WEP_IV_LEN;
key->conf.icv_len = IEEE80211_WEP_ICV_LEN;
break;
case WLAN_CIPHER_SUITE_TKIP:
key->conf.iv_len = IEEE80211_TKIP_IV_LEN;
key->conf.icv_len = IEEE80211_TKIP_ICV_LEN;
if (seq) {
for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
key->u.tkip.rx[i].iv32 =
get_unaligned_le32(&seq[2]);
key->u.tkip.rx[i].iv16 =
get_unaligned_le16(seq);
}
}
spin_lock_init(&key->u.tkip.txlock);
break;
case WLAN_CIPHER_SUITE_CCMP:
key->conf.iv_len = IEEE80211_CCMP_HDR_LEN;
key->conf.icv_len = IEEE80211_CCMP_MIC_LEN;
if (seq) {
for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
for (j = 0; j < IEEE80211_CCMP_PN_LEN; j++)
key->u.ccmp.rx_pn[i][j] =
seq[IEEE80211_CCMP_PN_LEN - j - 1];
}
/*
* Initialize AES key state here as an optimization so that
* it does not need to be initialized for every packet.
*/
key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
key_data, key_len, IEEE80211_CCMP_MIC_LEN);
if (IS_ERR(key->u.ccmp.tfm)) {
err = PTR_ERR(key->u.ccmp.tfm);
kfree(key);
return ERR_PTR(err);
}
break;
case WLAN_CIPHER_SUITE_CCMP_256:
key->conf.iv_len = IEEE80211_CCMP_256_HDR_LEN;
key->conf.icv_len = IEEE80211_CCMP_256_MIC_LEN;
for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
for (j = 0; j < IEEE80211_CCMP_256_PN_LEN; j++)
key->u.ccmp.rx_pn[i][j] =
seq[IEEE80211_CCMP_256_PN_LEN - j - 1];
/* Initialize AES key state here as an optimization so that
* it does not need to be initialized for every packet.
*/
key->u.ccmp.tfm = ieee80211_aes_key_setup_encrypt(
key_data, key_len, IEEE80211_CCMP_256_MIC_LEN);
if (IS_ERR(key->u.ccmp.tfm)) {
err = PTR_ERR(key->u.ccmp.tfm);
kfree(key);
return ERR_PTR(err);
}
break;
case WLAN_CIPHER_SUITE_AES_CMAC:
case WLAN_CIPHER_SUITE_BIP_CMAC_256:
key->conf.iv_len = 0;
if (cipher == WLAN_CIPHER_SUITE_AES_CMAC)
key->conf.icv_len = sizeof(struct ieee80211_mmie);
else
key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
if (seq)
for (j = 0; j < IEEE80211_CMAC_PN_LEN; j++)
key->u.aes_cmac.rx_pn[j] =
seq[IEEE80211_CMAC_PN_LEN - j - 1];
/*
* Initialize AES key state here as an optimization so that
* it does not need to be initialized for every packet.
*/
key->u.aes_cmac.tfm =
ieee80211_aes_cmac_key_setup(key_data, key_len);
if (IS_ERR(key->u.aes_cmac.tfm)) {
err = PTR_ERR(key->u.aes_cmac.tfm);
kfree(key);
return ERR_PTR(err);
}
break;
case WLAN_CIPHER_SUITE_BIP_GMAC_128:
case WLAN_CIPHER_SUITE_BIP_GMAC_256:
key->conf.iv_len = 0;
key->conf.icv_len = sizeof(struct ieee80211_mmie_16);
if (seq)
for (j = 0; j < IEEE80211_GMAC_PN_LEN; j++)
key->u.aes_gmac.rx_pn[j] =
seq[IEEE80211_GMAC_PN_LEN - j - 1];
/* Initialize AES key state here as an optimization so that
* it does not need to be initialized for every packet.
*/
key->u.aes_gmac.tfm =
ieee80211_aes_gmac_key_setup(key_data, key_len);
if (IS_ERR(key->u.aes_gmac.tfm)) {
err = PTR_ERR(key->u.aes_gmac.tfm);
kfree(key);
return ERR_PTR(err);
}
break;
case WLAN_CIPHER_SUITE_GCMP:
case WLAN_CIPHER_SUITE_GCMP_256:
key->conf.iv_len = IEEE80211_GCMP_HDR_LEN;
key->conf.icv_len = IEEE80211_GCMP_MIC_LEN;
for (i = 0; seq && i < IEEE80211_NUM_TIDS + 1; i++)
for (j = 0; j < IEEE80211_GCMP_PN_LEN; j++)
key->u.gcmp.rx_pn[i][j] =
seq[IEEE80211_GCMP_PN_LEN - j - 1];
/* Initialize AES key state here as an optimization so that
* it does not need to be initialized for every packet.
*/
key->u.gcmp.tfm = ieee80211_aes_gcm_key_setup_encrypt(key_data,
key_len);
if (IS_ERR(key->u.gcmp.tfm)) {
err = PTR_ERR(key->u.gcmp.tfm);
kfree(key);
return ERR_PTR(err);
}
break;
default:
if (cs) {
if (seq_len && seq_len != cs->pn_len) {
kfree(key);
return ERR_PTR(-EINVAL);
}
key->conf.iv_len = cs->hdr_len;
key->conf.icv_len = cs->mic_len;
for (i = 0; i < IEEE80211_NUM_TIDS + 1; i++)
for (j = 0; j < seq_len; j++)
key->u.gen.rx_pn[i][j] =
seq[seq_len - j - 1];
key->flags |= KEY_FLAG_CIPHER_SCHEME;
}
}
memcpy(key->conf.key, key_data, key_len);
INIT_LIST_HEAD(&key->list);
return key;
}
static void ieee80211_key_free_common(struct ieee80211_key *key)
{
switch (key->conf.cipher) {
case WLAN_CIPHER_SUITE_CCMP:
case WLAN_CIPHER_SUITE_CCMP_256:
ieee80211_aes_key_free(key->u.ccmp.tfm);
break;
case WLAN_CIPHER_SUITE_AES_CMAC:
case WLAN_CIPHER_SUITE_BIP_CMAC_256:
ieee80211_aes_cmac_key_free(key->u.aes_cmac.tfm);
break;
case WLAN_CIPHER_SUITE_BIP_GMAC_128:
case WLAN_CIPHER_SUITE_BIP_GMAC_256:
ieee80211_aes_gmac_key_free(key->u.aes_gmac.tfm);
break;
case WLAN_CIPHER_SUITE_GCMP:
case WLAN_CIPHER_SUITE_GCMP_256:
ieee80211_aes_gcm_key_free(key->u.gcmp.tfm);
break;
}
kfree_sensitive(key);
}
static void __ieee80211_key_destroy(struct ieee80211_key *key,
bool delay_tailroom)
{
if (key->local) {
struct ieee80211_sub_if_data *sdata = key->sdata;
ieee80211_debugfs_key_remove(key);
if (delay_tailroom) {
/* see ieee80211_delayed_tailroom_dec */
sdata->crypto_tx_tailroom_pending_dec++;
schedule_delayed_work(&sdata->dec_tailroom_needed_wk,
HZ/2);
} else {
decrease_tailroom_need_count(sdata, 1);
}
}
ieee80211_key_free_common(key);
}
static void ieee80211_key_destroy(struct ieee80211_key *key,
bool delay_tailroom)
{
if (!key)
return;
/*
* Synchronize so the TX path and rcu key iterators
* can no longer be using this key before we free/remove it.
*/
synchronize_net();
__ieee80211_key_destroy(key, delay_tailroom);
}
void ieee80211_key_free_unused(struct ieee80211_key *key)
{
WARN_ON(key->sdata || key->local);
ieee80211_key_free_common(key);
}
static bool ieee80211_key_identical(struct ieee80211_sub_if_data *sdata,
struct ieee80211_key *old,
struct ieee80211_key *new)
{
u8 tkip_old[WLAN_KEY_LEN_TKIP], tkip_new[WLAN_KEY_LEN_TKIP];
u8 *tk_old, *tk_new;
if (!old || new->conf.keylen != old->conf.keylen)
return false;
tk_old = old->conf.key;
tk_new = new->conf.key;
/*
* In station mode, don't compare the TX MIC key, as it's never used
* and offloaded rekeying may not care to send it to the host. This
* is the case in iwlwifi, for example.
*/
if (sdata->vif.type == NL80211_IFTYPE_STATION &&
new->conf.cipher == WLAN_CIPHER_SUITE_TKIP &&
new->conf.keylen == WLAN_KEY_LEN_TKIP &&
!(new->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE)) {
memcpy(tkip_old, tk_old, WLAN_KEY_LEN_TKIP);
memcpy(tkip_new, tk_new, WLAN_KEY_LEN_TKIP);
memset(tkip_old + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY, 0, 8);
memset(tkip_new + NL80211_TKIP_DATA_OFFSET_TX_MIC_KEY, 0, 8);
tk_old = tkip_old;
tk_new = tkip_new;
}
return !crypto_memneq(tk_old, tk_new, new->conf.keylen);
}
int ieee80211_key_link(struct ieee80211_key *key,
struct ieee80211_sub_if_data *sdata,
struct sta_info *sta)
{
static atomic_t key_color = ATOMIC_INIT(0);
struct ieee80211_key *old_key;
int idx = key->conf.keyidx;
bool pairwise = key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE;
/*
* We want to delay tailroom updates only for station - in that
* case it helps roaming speed, but in other cases it hurts and
* can cause warnings to appear.
*/
bool delay_tailroom = sdata->vif.type == NL80211_IFTYPE_STATION;
int ret = -EOPNOTSUPP;
mutex_lock(&sdata->local->key_mtx);
if (sta && pairwise) {
struct ieee80211_key *alt_key;
old_key = key_mtx_dereference(sdata->local, sta->ptk[idx]);
alt_key = key_mtx_dereference(sdata->local, sta->ptk[idx ^ 1]);
/* The rekey code assumes that the old and new key are using
* the same cipher. Enforce the assumption for pairwise keys.
*/
if ((alt_key && alt_key->conf.cipher != key->conf.cipher) ||
(old_key && old_key->conf.cipher != key->conf.cipher))
goto out;
} else if (sta) {
old_key = key_mtx_dereference(sdata->local, sta->gtk[idx]);
} else {
old_key = key_mtx_dereference(sdata->local, sdata->keys[idx]);
}
/* Non-pairwise keys must also not switch the cipher on rekey */
if (!pairwise) {
if (old_key && old_key->conf.cipher != key->conf.cipher)
goto out;
}
/*
* Silently accept key re-installation without really installing the
* new version of the key to avoid nonce reuse or replay issues.
*/
if (ieee80211_key_identical(sdata, old_key, key)) {
ieee80211_key_free_unused(key);
ret = 0;
goto out;
}
key->local = sdata->local;
key->sdata = sdata;
key->sta = sta;
/*
* Assign a unique ID to every key so we can easily prevent mixed
* key and fragment cache attacks.
*/
key->color = atomic_inc_return(&key_color);
increment_tailroom_need_count(sdata);
ret = ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
if (!ret) {
ieee80211_debugfs_key_add(key);
ieee80211_key_destroy(old_key, delay_tailroom);
} else {
ieee80211_key_free(key, delay_tailroom);
}
out:
mutex_unlock(&sdata->local->key_mtx);
return ret;
}
void ieee80211_key_free(struct ieee80211_key *key, bool delay_tailroom)
{
if (!key)
return;
/*
* Replace key with nothingness if it was ever used.
*/
if (key->sdata)
ieee80211_key_replace(key->sdata, key->sta,
key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
key, NULL);
ieee80211_key_destroy(key, delay_tailroom);
}
void ieee80211_reenable_keys(struct ieee80211_sub_if_data *sdata)
{
struct ieee80211_key *key;
struct ieee80211_sub_if_data *vlan;
ASSERT_RTNL();
mutex_lock(&sdata->local->key_mtx);
sdata->crypto_tx_tailroom_needed_cnt = 0;
sdata->crypto_tx_tailroom_pending_dec = 0;
if (sdata->vif.type == NL80211_IFTYPE_AP) {
list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
vlan->crypto_tx_tailroom_needed_cnt = 0;
vlan->crypto_tx_tailroom_pending_dec = 0;
}
}
if (ieee80211_sdata_running(sdata)) {
list_for_each_entry(key, &sdata->key_list, list) {
increment_tailroom_need_count(sdata);
ieee80211_key_enable_hw_accel(key);
}
}
mutex_unlock(&sdata->local->key_mtx);
}
void ieee80211_iter_keys(struct ieee80211_hw *hw,
struct ieee80211_vif *vif,
void (*iter)(struct ieee80211_hw *hw,
struct ieee80211_vif *vif,
struct ieee80211_sta *sta,
struct ieee80211_key_conf *key,
void *data),
void *iter_data)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_key *key, *tmp;
struct ieee80211_sub_if_data *sdata;
ASSERT_RTNL();
mutex_lock(&local->key_mtx);
if (vif) {
sdata = vif_to_sdata(vif);
list_for_each_entry_safe(key, tmp, &sdata->key_list, list)
iter(hw, &sdata->vif,
key->sta ? &key->sta->sta : NULL,
&key->conf, iter_data);
} else {
list_for_each_entry(sdata, &local->interfaces, list)
list_for_each_entry_safe(key, tmp,
&sdata->key_list, list)
iter(hw, &sdata->vif,
key->sta ? &key->sta->sta : NULL,
&key->conf, iter_data);
}
mutex_unlock(&local->key_mtx);
}
EXPORT_SYMBOL(ieee80211_iter_keys);
static void
_ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
struct ieee80211_sub_if_data *sdata,
void (*iter)(struct ieee80211_hw *hw,
struct ieee80211_vif *vif,
struct ieee80211_sta *sta,
struct ieee80211_key_conf *key,
void *data),
void *iter_data)
{
struct ieee80211_key *key;
list_for_each_entry_rcu(key, &sdata->key_list, list) {
/* skip keys of station in removal process */
if (key->sta && key->sta->removed)
continue;
if (!(key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE))
continue;
iter(hw, &sdata->vif,
key->sta ? &key->sta->sta : NULL,
&key->conf, iter_data);
}
}
void ieee80211_iter_keys_rcu(struct ieee80211_hw *hw,
struct ieee80211_vif *vif,
void (*iter)(struct ieee80211_hw *hw,
struct ieee80211_vif *vif,
struct ieee80211_sta *sta,
struct ieee80211_key_conf *key,
void *data),
void *iter_data)
{
struct ieee80211_local *local = hw_to_local(hw);
struct ieee80211_sub_if_data *sdata;
if (vif) {
sdata = vif_to_sdata(vif);
_ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
} else {
list_for_each_entry_rcu(sdata, &local->interfaces, list)
_ieee80211_iter_keys_rcu(hw, sdata, iter, iter_data);
}
}
EXPORT_SYMBOL(ieee80211_iter_keys_rcu);
static void ieee80211_free_keys_iface(struct ieee80211_sub_if_data *sdata,
struct list_head *keys)
{
struct ieee80211_key *key, *tmp;
decrease_tailroom_need_count(sdata,
sdata->crypto_tx_tailroom_pending_dec);
sdata->crypto_tx_tailroom_pending_dec = 0;
ieee80211_debugfs_key_remove_mgmt_default(sdata);
ieee80211_debugfs_key_remove_beacon_default(sdata);
list_for_each_entry_safe(key, tmp, &sdata->key_list, list) {
ieee80211_key_replace(key->sdata, key->sta,
key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
key, NULL);
list_add_tail(&key->list, keys);
}
ieee80211_debugfs_key_update_default(sdata);
}
void ieee80211_free_keys(struct ieee80211_sub_if_data *sdata,
bool force_synchronize)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_sub_if_data *vlan;
struct ieee80211_sub_if_data *master;
struct ieee80211_key *key, *tmp;
LIST_HEAD(keys);
cancel_delayed_work_sync(&sdata->dec_tailroom_needed_wk);
mutex_lock(&local->key_mtx);
ieee80211_free_keys_iface(sdata, &keys);
if (sdata->vif.type == NL80211_IFTYPE_AP) {
list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
ieee80211_free_keys_iface(vlan, &keys);
}
if (!list_empty(&keys) || force_synchronize)
synchronize_net();
list_for_each_entry_safe(key, tmp, &keys, list)
__ieee80211_key_destroy(key, false);
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
if (sdata->bss) {
master = container_of(sdata->bss,
struct ieee80211_sub_if_data,
u.ap);
WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt !=
master->crypto_tx_tailroom_needed_cnt);
}
} else {
WARN_ON_ONCE(sdata->crypto_tx_tailroom_needed_cnt ||
sdata->crypto_tx_tailroom_pending_dec);
}
if (sdata->vif.type == NL80211_IFTYPE_AP) {
list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list)
WARN_ON_ONCE(vlan->crypto_tx_tailroom_needed_cnt ||
vlan->crypto_tx_tailroom_pending_dec);
}
mutex_unlock(&local->key_mtx);
}
void ieee80211_free_sta_keys(struct ieee80211_local *local,
struct sta_info *sta)
{
struct ieee80211_key *key;
int i;
mutex_lock(&local->key_mtx);
for (i = 0; i < ARRAY_SIZE(sta->gtk); i++) {
key = key_mtx_dereference(local, sta->gtk[i]);
if (!key)
continue;
ieee80211_key_replace(key->sdata, key->sta,
key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
key, NULL);
__ieee80211_key_destroy(key, key->sdata->vif.type ==
NL80211_IFTYPE_STATION);
}
for (i = 0; i < NUM_DEFAULT_KEYS; i++) {
key = key_mtx_dereference(local, sta->ptk[i]);
if (!key)
continue;
ieee80211_key_replace(key->sdata, key->sta,
key->conf.flags & IEEE80211_KEY_FLAG_PAIRWISE,
key, NULL);
__ieee80211_key_destroy(key, key->sdata->vif.type ==
NL80211_IFTYPE_STATION);
}
mutex_unlock(&local->key_mtx);
}
void ieee80211_delayed_tailroom_dec(struct work_struct *wk)
{
struct ieee80211_sub_if_data *sdata;
sdata = container_of(wk, struct ieee80211_sub_if_data,
dec_tailroom_needed_wk.work);
/*
* The reason for the delayed tailroom needed decrementing is to
* make roaming faster: during roaming, all keys are first deleted
* and then new keys are installed. The first new key causes the
* crypto_tx_tailroom_needed_cnt to go from 0 to 1, which invokes
* the cost of synchronize_net() (which can be slow). Avoid this
* by deferring the crypto_tx_tailroom_needed_cnt decrementing on
* key removal for a while, so if we roam the value is larger than
* zero and no 0->1 transition happens.
*
* The cost is that if the AP switching was from an AP with keys
* to one without, we still allocate tailroom while it would no
* longer be needed. However, in the typical (fast) roaming case
* within an ESS this usually won't happen.
*/
mutex_lock(&sdata->local->key_mtx);
decrease_tailroom_need_count(sdata,
sdata->crypto_tx_tailroom_pending_dec);
sdata->crypto_tx_tailroom_pending_dec = 0;
mutex_unlock(&sdata->local->key_mtx);
}
void ieee80211_gtk_rekey_notify(struct ieee80211_vif *vif, const u8 *bssid,
const u8 *replay_ctr, gfp_t gfp)
{
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
trace_api_gtk_rekey_notify(sdata, bssid, replay_ctr);
cfg80211_gtk_rekey_notify(sdata->dev, bssid, replay_ctr, gfp);
}
EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_notify);
void ieee80211_get_key_rx_seq(struct ieee80211_key_conf *keyconf,
int tid, struct ieee80211_key_seq *seq)
{
struct ieee80211_key *key;
const u8 *pn;
key = container_of(keyconf, struct ieee80211_key, conf);
switch (key->conf.cipher) {
case WLAN_CIPHER_SUITE_TKIP:
if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
return;
seq->tkip.iv32 = key->u.tkip.rx[tid].iv32;
seq->tkip.iv16 = key->u.tkip.rx[tid].iv16;
break;
case WLAN_CIPHER_SUITE_CCMP:
case WLAN_CIPHER_SUITE_CCMP_256:
if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
return;
if (tid < 0)
pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
else
pn = key->u.ccmp.rx_pn[tid];
memcpy(seq->ccmp.pn, pn, IEEE80211_CCMP_PN_LEN);
break;
case WLAN_CIPHER_SUITE_AES_CMAC:
case WLAN_CIPHER_SUITE_BIP_CMAC_256:
if (WARN_ON(tid != 0))
return;
pn = key->u.aes_cmac.rx_pn;
memcpy(seq->aes_cmac.pn, pn, IEEE80211_CMAC_PN_LEN);
break;
case WLAN_CIPHER_SUITE_BIP_GMAC_128:
case WLAN_CIPHER_SUITE_BIP_GMAC_256:
if (WARN_ON(tid != 0))
return;
pn = key->u.aes_gmac.rx_pn;
memcpy(seq->aes_gmac.pn, pn, IEEE80211_GMAC_PN_LEN);
break;
case WLAN_CIPHER_SUITE_GCMP:
case WLAN_CIPHER_SUITE_GCMP_256:
if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
return;
if (tid < 0)
pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
else
pn = key->u.gcmp.rx_pn[tid];
memcpy(seq->gcmp.pn, pn, IEEE80211_GCMP_PN_LEN);
break;
}
}
EXPORT_SYMBOL(ieee80211_get_key_rx_seq);
void ieee80211_set_key_rx_seq(struct ieee80211_key_conf *keyconf,
int tid, struct ieee80211_key_seq *seq)
{
struct ieee80211_key *key;
u8 *pn;
key = container_of(keyconf, struct ieee80211_key, conf);
switch (key->conf.cipher) {
case WLAN_CIPHER_SUITE_TKIP:
if (WARN_ON(tid < 0 || tid >= IEEE80211_NUM_TIDS))
return;
key->u.tkip.rx[tid].iv32 = seq->tkip.iv32;
key->u.tkip.rx[tid].iv16 = seq->tkip.iv16;
break;
case WLAN_CIPHER_SUITE_CCMP:
case WLAN_CIPHER_SUITE_CCMP_256:
if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
return;
if (tid < 0)
pn = key->u.ccmp.rx_pn[IEEE80211_NUM_TIDS];
else
pn = key->u.ccmp.rx_pn[tid];
memcpy(pn, seq->ccmp.pn, IEEE80211_CCMP_PN_LEN);
break;
case WLAN_CIPHER_SUITE_AES_CMAC:
case WLAN_CIPHER_SUITE_BIP_CMAC_256:
if (WARN_ON(tid != 0))
return;
pn = key->u.aes_cmac.rx_pn;
memcpy(pn, seq->aes_cmac.pn, IEEE80211_CMAC_PN_LEN);
break;
case WLAN_CIPHER_SUITE_BIP_GMAC_128:
case WLAN_CIPHER_SUITE_BIP_GMAC_256:
if (WARN_ON(tid != 0))
return;
pn = key->u.aes_gmac.rx_pn;
memcpy(pn, seq->aes_gmac.pn, IEEE80211_GMAC_PN_LEN);
break;
case WLAN_CIPHER_SUITE_GCMP:
case WLAN_CIPHER_SUITE_GCMP_256:
if (WARN_ON(tid < -1 || tid >= IEEE80211_NUM_TIDS))
return;
if (tid < 0)
pn = key->u.gcmp.rx_pn[IEEE80211_NUM_TIDS];
else
pn = key->u.gcmp.rx_pn[tid];
memcpy(pn, seq->gcmp.pn, IEEE80211_GCMP_PN_LEN);
break;
default:
WARN_ON(1);
break;
}
}
EXPORT_SYMBOL_GPL(ieee80211_set_key_rx_seq);
void ieee80211_remove_key(struct ieee80211_key_conf *keyconf)
{
struct ieee80211_key *key;
key = container_of(keyconf, struct ieee80211_key, conf);
assert_key_lock(key->local);
/*
* if key was uploaded, we assume the driver will/has remove(d)
* it, so adjust bookkeeping accordingly
*/
if (key->flags & KEY_FLAG_UPLOADED_TO_HARDWARE) {
key->flags &= ~KEY_FLAG_UPLOADED_TO_HARDWARE;
if (!(key->conf.flags & (IEEE80211_KEY_FLAG_GENERATE_MMIC |
IEEE80211_KEY_FLAG_PUT_MIC_SPACE |
IEEE80211_KEY_FLAG_RESERVE_TAILROOM)))
increment_tailroom_need_count(key->sdata);
}
ieee80211_key_free(key, false);
}
EXPORT_SYMBOL_GPL(ieee80211_remove_key);
struct ieee80211_key_conf *
ieee80211_gtk_rekey_add(struct ieee80211_vif *vif,
struct ieee80211_key_conf *keyconf)
{
struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
struct ieee80211_local *local = sdata->local;
struct ieee80211_key *key;
int err;
if (WARN_ON(!local->wowlan))
return ERR_PTR(-EINVAL);
if (WARN_ON(vif->type != NL80211_IFTYPE_STATION))
return ERR_PTR(-EINVAL);
key = ieee80211_key_alloc(keyconf->cipher, keyconf->keyidx,
keyconf->keylen, keyconf->key,
0, NULL, NULL);
if (IS_ERR(key))
return ERR_CAST(key);
if (sdata->u.mgd.mfp != IEEE80211_MFP_DISABLED)
key->conf.flags |= IEEE80211_KEY_FLAG_RX_MGMT;
err = ieee80211_key_link(key, sdata, NULL);
if (err)
return ERR_PTR(err);
return &key->conf;
}
EXPORT_SYMBOL_GPL(ieee80211_gtk_rekey_add);
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