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-rw-r--r--net/mac80211/rx.c150
1 files changed, 117 insertions, 33 deletions
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 62047e93e217..1bb43edd47b6 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -6,7 +6,7 @@
* Copyright 2007-2010 Johannes Berg <johannes@sipsolutions.net>
* Copyright 2013-2014 Intel Mobile Communications GmbH
* Copyright(c) 2015 - 2017 Intel Deutschland GmbH
- * Copyright (C) 2018-2020 Intel Corporation
+ * Copyright (C) 2018-2021 Intel Corporation
*/
#include <linux/jiffies.h>
@@ -2123,19 +2123,34 @@ ieee80211_rx_h_decrypt(struct ieee80211_rx_data *rx)
return result;
}
+void ieee80211_init_frag_cache(struct ieee80211_fragment_cache *cache)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(cache->entries); i++)
+ skb_queue_head_init(&cache->entries[i].skb_list);
+}
+
+void ieee80211_destroy_frag_cache(struct ieee80211_fragment_cache *cache)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(cache->entries); i++)
+ __skb_queue_purge(&cache->entries[i].skb_list);
+}
+
static inline struct ieee80211_fragment_entry *
-ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
+ieee80211_reassemble_add(struct ieee80211_fragment_cache *cache,
unsigned int frag, unsigned int seq, int rx_queue,
struct sk_buff **skb)
{
struct ieee80211_fragment_entry *entry;
- entry = &sdata->fragments[sdata->fragment_next++];
- if (sdata->fragment_next >= IEEE80211_FRAGMENT_MAX)
- sdata->fragment_next = 0;
+ entry = &cache->entries[cache->next++];
+ if (cache->next >= IEEE80211_FRAGMENT_MAX)
+ cache->next = 0;
- if (!skb_queue_empty(&entry->skb_list))
- __skb_queue_purge(&entry->skb_list);
+ __skb_queue_purge(&entry->skb_list);
__skb_queue_tail(&entry->skb_list, *skb); /* no need for locking */
*skb = NULL;
@@ -2150,14 +2165,14 @@ ieee80211_reassemble_add(struct ieee80211_sub_if_data *sdata,
}
static inline struct ieee80211_fragment_entry *
-ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
+ieee80211_reassemble_find(struct ieee80211_fragment_cache *cache,
unsigned int frag, unsigned int seq,
int rx_queue, struct ieee80211_hdr *hdr)
{
struct ieee80211_fragment_entry *entry;
int i, idx;
- idx = sdata->fragment_next;
+ idx = cache->next;
for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++) {
struct ieee80211_hdr *f_hdr;
struct sk_buff *f_skb;
@@ -2166,7 +2181,7 @@ ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
if (idx < 0)
idx = IEEE80211_FRAGMENT_MAX - 1;
- entry = &sdata->fragments[idx];
+ entry = &cache->entries[idx];
if (skb_queue_empty(&entry->skb_list) || entry->seq != seq ||
entry->rx_queue != rx_queue ||
entry->last_frag + 1 != frag)
@@ -2194,15 +2209,27 @@ ieee80211_reassemble_find(struct ieee80211_sub_if_data *sdata,
return NULL;
}
+static bool requires_sequential_pn(struct ieee80211_rx_data *rx, __le16 fc)
+{
+ return rx->key &&
+ (rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP ||
+ rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP_256 ||
+ rx->key->conf.cipher == WLAN_CIPHER_SUITE_GCMP ||
+ rx->key->conf.cipher == WLAN_CIPHER_SUITE_GCMP_256) &&
+ ieee80211_has_protected(fc);
+}
+
static ieee80211_rx_result debug_noinline
ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
{
+ struct ieee80211_fragment_cache *cache = &rx->sdata->frags;
struct ieee80211_hdr *hdr;
u16 sc;
__le16 fc;
unsigned int frag, seq;
struct ieee80211_fragment_entry *entry;
struct sk_buff *skb;
+ struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
hdr = (struct ieee80211_hdr *)rx->skb->data;
fc = hdr->frame_control;
@@ -2218,6 +2245,9 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
goto out_no_led;
}
+ if (rx->sta)
+ cache = &rx->sta->frags;
+
if (likely(!ieee80211_has_morefrags(fc) && frag == 0))
goto out;
@@ -2236,20 +2266,17 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
if (frag == 0) {
/* This is the first fragment of a new frame. */
- entry = ieee80211_reassemble_add(rx->sdata, frag, seq,
+ entry = ieee80211_reassemble_add(cache, frag, seq,
rx->seqno_idx, &(rx->skb));
- if (rx->key &&
- (rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP ||
- rx->key->conf.cipher == WLAN_CIPHER_SUITE_CCMP_256 ||
- rx->key->conf.cipher == WLAN_CIPHER_SUITE_GCMP ||
- rx->key->conf.cipher == WLAN_CIPHER_SUITE_GCMP_256) &&
- ieee80211_has_protected(fc)) {
+ if (requires_sequential_pn(rx, fc)) {
int queue = rx->security_idx;
/* Store CCMP/GCMP PN so that we can verify that the
* next fragment has a sequential PN value.
*/
entry->check_sequential_pn = true;
+ entry->is_protected = true;
+ entry->key_color = rx->key->color;
memcpy(entry->last_pn,
rx->key->u.ccmp.rx_pn[queue],
IEEE80211_CCMP_PN_LEN);
@@ -2261,6 +2288,11 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
sizeof(rx->key->u.gcmp.rx_pn[queue]));
BUILD_BUG_ON(IEEE80211_CCMP_PN_LEN !=
IEEE80211_GCMP_PN_LEN);
+ } else if (rx->key &&
+ (ieee80211_has_protected(fc) ||
+ (status->flag & RX_FLAG_DECRYPTED))) {
+ entry->is_protected = true;
+ entry->key_color = rx->key->color;
}
return RX_QUEUED;
}
@@ -2268,7 +2300,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
/* This is a fragment for a frame that should already be pending in
* fragment cache. Add this fragment to the end of the pending entry.
*/
- entry = ieee80211_reassemble_find(rx->sdata, frag, seq,
+ entry = ieee80211_reassemble_find(cache, frag, seq,
rx->seqno_idx, hdr);
if (!entry) {
I802_DEBUG_INC(rx->local->rx_handlers_drop_defrag);
@@ -2283,25 +2315,39 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
if (entry->check_sequential_pn) {
int i;
u8 pn[IEEE80211_CCMP_PN_LEN], *rpn;
- int queue;
- if (!rx->key ||
- (rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP &&
- rx->key->conf.cipher != WLAN_CIPHER_SUITE_CCMP_256 &&
- rx->key->conf.cipher != WLAN_CIPHER_SUITE_GCMP &&
- rx->key->conf.cipher != WLAN_CIPHER_SUITE_GCMP_256))
+ if (!requires_sequential_pn(rx, fc))
+ return RX_DROP_UNUSABLE;
+
+ /* Prevent mixed key and fragment cache attacks */
+ if (entry->key_color != rx->key->color)
return RX_DROP_UNUSABLE;
+
memcpy(pn, entry->last_pn, IEEE80211_CCMP_PN_LEN);
for (i = IEEE80211_CCMP_PN_LEN - 1; i >= 0; i--) {
pn[i]++;
if (pn[i])
break;
}
- queue = rx->security_idx;
- rpn = rx->key->u.ccmp.rx_pn[queue];
+
+ rpn = rx->ccm_gcm.pn;
if (memcmp(pn, rpn, IEEE80211_CCMP_PN_LEN))
return RX_DROP_UNUSABLE;
memcpy(entry->last_pn, pn, IEEE80211_CCMP_PN_LEN);
+ } else if (entry->is_protected &&
+ (!rx->key ||
+ (!ieee80211_has_protected(fc) &&
+ !(status->flag & RX_FLAG_DECRYPTED)) ||
+ rx->key->color != entry->key_color)) {
+ /* Drop this as a mixed key or fragment cache attack, even
+ * if for TKIP Michael MIC should protect us, and WEP is a
+ * lost cause anyway.
+ */
+ return RX_DROP_UNUSABLE;
+ } else if (entry->is_protected && rx->key &&
+ entry->key_color != rx->key->color &&
+ (status->flag & RX_FLAG_DECRYPTED)) {
+ return RX_DROP_UNUSABLE;
}
skb_pull(rx->skb, ieee80211_hdrlen(fc));
@@ -2494,13 +2540,13 @@ static bool ieee80211_frame_allowed(struct ieee80211_rx_data *rx, __le16 fc)
struct ethhdr *ehdr = (struct ethhdr *) rx->skb->data;
/*
- * Allow EAPOL frames to us/the PAE group address regardless
- * of whether the frame was encrypted or not.
+ * Allow EAPOL frames to us/the PAE group address regardless of
+ * whether the frame was encrypted or not, and always disallow
+ * all other destination addresses for them.
*/
- if (ehdr->h_proto == rx->sdata->control_port_protocol &&
- (ether_addr_equal(ehdr->h_dest, rx->sdata->vif.addr) ||
- ether_addr_equal(ehdr->h_dest, pae_group_addr)))
- return true;
+ if (unlikely(ehdr->h_proto == rx->sdata->control_port_protocol))
+ return ether_addr_equal(ehdr->h_dest, rx->sdata->vif.addr) ||
+ ether_addr_equal(ehdr->h_dest, pae_group_addr);
if (ieee80211_802_1x_port_control(rx) ||
ieee80211_drop_unencrypted(rx, fc))
@@ -2525,8 +2571,28 @@ static void ieee80211_deliver_skb_to_local_stack(struct sk_buff *skb,
cfg80211_rx_control_port(dev, skb, noencrypt);
dev_kfree_skb(skb);
} else {
+ struct ethhdr *ehdr = (void *)skb_mac_header(skb);
+
memset(skb->cb, 0, sizeof(skb->cb));
+ /*
+ * 802.1X over 802.11 requires that the authenticator address
+ * be used for EAPOL frames. However, 802.1X allows the use of
+ * the PAE group address instead. If the interface is part of
+ * a bridge and we pass the frame with the PAE group address,
+ * then the bridge will forward it to the network (even if the
+ * client was not associated yet), which isn't supposed to
+ * happen.
+ * To avoid that, rewrite the destination address to our own
+ * address, so that the authenticator (e.g. hostapd) will see
+ * the frame, but bridge won't forward it anywhere else. Note
+ * that due to earlier filtering, the only other address can
+ * be the PAE group address.
+ */
+ if (unlikely(skb->protocol == sdata->control_port_protocol &&
+ !ether_addr_equal(ehdr->h_dest, sdata->vif.addr)))
+ ether_addr_copy(ehdr->h_dest, sdata->vif.addr);
+
/* deliver to local stack */
if (rx->list)
list_add_tail(&skb->list, rx->list);
@@ -2566,6 +2632,7 @@ ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
if ((sdata->vif.type == NL80211_IFTYPE_AP ||
sdata->vif.type == NL80211_IFTYPE_AP_VLAN) &&
!(sdata->flags & IEEE80211_SDATA_DONT_BRIDGE_PACKETS) &&
+ ehdr->h_proto != rx->sdata->control_port_protocol &&
(sdata->vif.type != NL80211_IFTYPE_AP_VLAN || !sdata->u.vlan.sta)) {
if (is_multicast_ether_addr(ehdr->h_dest) &&
ieee80211_vif_get_num_mcast_if(sdata) != 0) {
@@ -2675,7 +2742,7 @@ __ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx, u8 data_offset)
if (ieee80211_data_to_8023_exthdr(skb, &ethhdr,
rx->sdata->vif.addr,
rx->sdata->vif.type,
- data_offset))
+ data_offset, true))
return RX_DROP_UNUSABLE;
ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
@@ -2732,6 +2799,23 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
if (is_multicast_ether_addr(hdr->addr1))
return RX_DROP_UNUSABLE;
+ if (rx->key) {
+ /*
+ * We should not receive A-MSDUs on pre-HT connections,
+ * and HT connections cannot use old ciphers. Thus drop
+ * them, as in those cases we couldn't even have SPP
+ * A-MSDUs or such.
+ */
+ switch (rx->key->conf.cipher) {
+ case WLAN_CIPHER_SUITE_WEP40:
+ case WLAN_CIPHER_SUITE_WEP104:
+ case WLAN_CIPHER_SUITE_TKIP:
+ return RX_DROP_UNUSABLE;
+ default:
+ break;
+ }
+ }
+
return __ieee80211_rx_h_amsdu(rx, 0);
}