From 16cbc9756dd84e870867f003a200553931dd461b Mon Sep 17 00:00:00 2001
From: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>
Date: Mon, 31 May 2021 22:28:25 +0200
Subject: mac80211: assure all fragments are encrypted

commit 965a7d72e798eb7af0aa67210e37cf7ecd1c9cad upstream.

Do not mix plaintext and encrypted fragments in protected Wi-Fi
networks. This fixes CVE-2020-26147.

Previously, an attacker was able to first forward a legitimate encrypted
fragment towards a victim, followed by a plaintext fragment. The
encrypted and plaintext fragment would then be reassembled. For further
details see Section 6.3 and Appendix D in the paper "Fragment and Forge:
Breaking Wi-Fi Through Frame Aggregation and Fragmentation".

Because of this change there are now two equivalent conditions in the
code to determine if a received fragment requires sequential PNs, so we
also move this test to a separate function to make the code easier to
maintain.

Cc: stable@vger.kernel.org
Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>
Link: https://lore.kernel.org/r/20210511200110.30c4394bb835.I5acfdb552cc1d20c339c262315950b3eac491397@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/mac80211/rx.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

(limited to 'net/mac80211')

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 886dce84e70c..eaad526cd0bf 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1807,6 +1807,16 @@ 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)
 {
@@ -1852,12 +1862,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 		/* This is the first fragment of a new frame. */
 		entry = ieee80211_reassemble_add(rx->sdata, 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
@@ -1899,11 +1904,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 		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;
 		memcpy(pn, entry->last_pn, IEEE80211_CCMP_PN_LEN);
 		for (i = IEEE80211_CCMP_PN_LEN - 1; i >= 0; i--) {
-- 
cgit v1.2.3


From 229fa01b0bd72559e5c5b99e402f180e47ad86a8 Mon Sep 17 00:00:00 2001
From: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>
Date: Mon, 31 May 2021 22:28:26 +0200
Subject: 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>
---
 net/mac80211/ieee80211_i.h | 1 +
 net/mac80211/key.c         | 7 +++++++
 net/mac80211/key.h         | 2 ++
 net/mac80211/rx.c          | 6 ++++++
 4 files changed, 16 insertions(+)

(limited to 'net/mac80211')

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 1046520d726d..16510a57f2e7 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -94,6 +94,7 @@ struct ieee80211_fragment_entry {
 	u8 rx_queue;
 	bool check_sequential_pn; /* needed for CCMP/GCMP */
 	u8 last_pn[6]; /* PN of the last fragment if CCMP was used */
+	unsigned int key_color;
 };
 
 
diff --git a/net/mac80211/key.c b/net/mac80211/key.c
index 91a4e606edcd..a2050d5776ce 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -646,6 +646,7 @@ int ieee80211_key_link(struct ieee80211_key *key,
 		       struct sta_info *sta)
 {
 	struct ieee80211_local *local = sdata->local;
+	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;
@@ -680,6 +681,12 @@ int ieee80211_key_link(struct ieee80211_key *key,
 	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);
 
 	ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
diff --git a/net/mac80211/key.h b/net/mac80211/key.h
index 9951ef06323e..9ac5c00dbe80 100644
--- a/net/mac80211/key.h
+++ b/net/mac80211/key.h
@@ -123,6 +123,8 @@ struct ieee80211_key {
 	} debugfs;
 #endif
 
+	unsigned int color;
+
 	/*
 	 * key config, must be last because it contains key
 	 * material as variable length member
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index eaad526cd0bf..85d7ac83d847 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1869,6 +1869,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 			 * next fragment has a sequential PN value.
 			 */
 			entry->check_sequential_pn = true;
+			entry->key_color = rx->key->color;
 			memcpy(entry->last_pn,
 			       rx->key->u.ccmp.rx_pn[queue],
 			       IEEE80211_CCMP_PN_LEN);
@@ -1906,6 +1907,11 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 
 		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]++;
-- 
cgit v1.2.3


From 53a9c079c1f00db46393d10cd1798c12de40fe77 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Mon, 31 May 2021 22:28:29 +0200
Subject: mac80211: drop A-MSDUs on old ciphers

commit 270032a2a9c4535799736142e1e7c413ca7b836e upstream.

With old ciphers (WEP and TKIP) we shouldn't be using A-MSDUs
since A-MSDUs are only supported if we know that they are, and
the only practical way for that is HT support which doesn't
support old ciphers.

However, we would normally accept them anyway. Since we check
the MMIC before deaggregating A-MSDUs, and the A-MSDU bit in
the QoS header is not protected in TKIP (or WEP), this enables
attacks similar to CVE-2020-24588. To prevent that, drop A-MSDUs
completely with old ciphers.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.076543300172.I548e6e71f1ee9cad4b9a37bf212ae7db723587aa@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/mac80211/rx.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

(limited to 'net/mac80211')

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 85d7ac83d847..23c1e6529900 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2264,6 +2264,23 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx_data *rx)
 	if (skb_linearize(skb))
 		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;
+		}
+	}
+
 	ieee80211_amsdu_to_8023s(skb, &frame_list, dev->dev_addr,
 				 rx->sdata->vif.type,
 				 rx->local->hw.extra_tx_headroom, true);
-- 
cgit v1.2.3


From c1073dd6d45f1a9bd6fc586b2ae09ae822e28588 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Mon, 31 May 2021 22:28:30 +0200
Subject: mac80211: add fragment cache to sta_info

commit 3a11ce08c45b50d69c891d71760b7c5b92074709 upstream.

Prior patches protected against fragmentation cache attacks
by coloring keys, but this shows that it can lead to issues
when multiple stations use the same sequence number. Add a
fragment cache to struct sta_info (in addition to the one in
the interface) to separate fragments for different stations
properly.

This then automatically clear most of the fragment cache when a
station disconnects (or reassociates) from an AP, or when client
interfaces disconnect from the network, etc.

On the way, also fix the comment there since this brings us in line
with the recommendation in 802.11-2016 ("An AP should support ...").
Additionally, remove a useless condition (since there's no problem
purging an already empty list).

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.fc35046b0d52.I1ef101e3784d13e8f6600d83de7ec9a3a45bcd52@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/mac80211/ieee80211_i.h | 26 ++++----------------------
 net/mac80211/iface.c       |  9 ++-------
 net/mac80211/rx.c          | 41 ++++++++++++++++++++++++++++++-----------
 net/mac80211/sta_info.c    |  4 ++++
 net/mac80211/sta_info.h    | 30 ++++++++++++++++++++++++++++++
 5 files changed, 70 insertions(+), 40 deletions(-)

(limited to 'net/mac80211')

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 16510a57f2e7..3f270fe15779 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -51,12 +51,6 @@ struct ieee80211_local;
 #define IEEE80211_ENCRYPT_HEADROOM 8
 #define IEEE80211_ENCRYPT_TAILROOM 18
 
-/* IEEE 802.11 (Ch. 9.5 Defragmentation) requires support for concurrent
- * reception of at least three fragmented frames. This limit can be increased
- * by changing this define, at the cost of slower frame reassembly and
- * increased memory use (about 2 kB of RAM per entry). */
-#define IEEE80211_FRAGMENT_MAX 4
-
 /* power level hasn't been configured (or set to automatic) */
 #define IEEE80211_UNSET_POWER_LEVEL	INT_MIN
 
@@ -85,19 +79,6 @@ struct ieee80211_local;
 
 #define IEEE80211_DEAUTH_FRAME_LEN	(24 /* hdr */ + 2 /* reason */)
 
-struct ieee80211_fragment_entry {
-	struct sk_buff_head skb_list;
-	unsigned long first_frag_time;
-	u16 seq;
-	u16 extra_len;
-	u16 last_frag;
-	u8 rx_queue;
-	bool check_sequential_pn; /* needed for CCMP/GCMP */
-	u8 last_pn[6]; /* PN of the last fragment if CCMP was used */
-	unsigned int key_color;
-};
-
-
 struct ieee80211_bss {
 	u32 device_ts_beacon, device_ts_presp;
 
@@ -835,9 +816,7 @@ struct ieee80211_sub_if_data {
 
 	char name[IFNAMSIZ];
 
-	/* Fragment table for host-based reassembly */
-	struct ieee80211_fragment_entry	fragments[IEEE80211_FRAGMENT_MAX];
-	unsigned int fragment_next;
+	struct ieee80211_fragment_cache frags;
 
 	/* TID bitmap for NoAck policy */
 	u16 noack_map;
@@ -2077,4 +2056,7 @@ extern const struct ethtool_ops ieee80211_ethtool_ops;
 #define debug_noinline
 #endif
 
+void ieee80211_init_frag_cache(struct ieee80211_fragment_cache *cache);
+void ieee80211_destroy_frag_cache(struct ieee80211_fragment_cache *cache);
+
 #endif /* IEEE80211_I_H */
diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 6d12a893eb11..9a110f9f5604 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1082,16 +1082,12 @@ static void ieee80211_set_multicast_list(struct net_device *dev)
  */
 static void ieee80211_teardown_sdata(struct ieee80211_sub_if_data *sdata)
 {
-	int i;
-
 	/* free extra data */
 	ieee80211_free_keys(sdata, false);
 
 	ieee80211_debugfs_remove_netdev(sdata);
 
-	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
-		__skb_queue_purge(&sdata->fragments[i].skb_list);
-	sdata->fragment_next = 0;
+	ieee80211_destroy_frag_cache(&sdata->frags);
 
 	if (ieee80211_vif_is_mesh(&sdata->vif))
 		mesh_rmc_free(sdata);
@@ -1787,8 +1783,7 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 	sdata->wdev.wiphy = local->hw.wiphy;
 	sdata->local = local;
 
-	for (i = 0; i < IEEE80211_FRAGMENT_MAX; i++)
-		skb_queue_head_init(&sdata->fragments[i].skb_list);
+	ieee80211_init_frag_cache(&sdata->frags);
 
 	INIT_LIST_HEAD(&sdata->key_list);
 
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 23c1e6529900..a93dd83b77af 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1738,19 +1738,34 @@ 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;
@@ -1765,14 +1780,14 @@ 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;
 
@@ -1780,7 +1795,7 @@ 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)
@@ -1820,6 +1835,7 @@ static bool requires_sequential_pn(struct ieee80211_rx_data *rx, __le16 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;
@@ -1842,6 +1858,9 @@ 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;
 
@@ -1860,7 +1879,7 @@ 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 (requires_sequential_pn(rx, fc)) {
 			int queue = rx->security_idx;
@@ -1888,7 +1907,7 @@ 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);
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index e63d64e1225d..cdf3abaad14d 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -355,6 +355,8 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
 	sta->sdata = sdata;
 	sta->rx_stats.last_rx = jiffies;
 
+	ieee80211_init_frag_cache(&sta->frags);
+
 	sta->sta_state = IEEE80211_STA_NONE;
 
 	/* Mark TID as unreserved */
@@ -974,6 +976,8 @@ static void __sta_info_destroy_part2(struct sta_info *sta)
 	ieee80211_sta_debugfs_remove(sta);
 	ieee80211_recalc_min_chandef(sdata);
 
+	ieee80211_destroy_frag_cache(&sta->frags);
+
 	cleanup_single_sta(sta);
 }
 
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 15b0150283b6..1b178cc42d3a 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -324,6 +324,33 @@ struct mesh_sta {
 
 DECLARE_EWMA(signal, 1024, 8)
 
+/*
+ * IEEE 802.11-2016 (10.6 "Defragmentation") recommends support for "concurrent
+ * reception of at least one MSDU per access category per associated STA"
+ * on APs, or "at least one MSDU per access category" on other interface types.
+ *
+ * This limit can be increased by changing this define, at the cost of slower
+ * frame reassembly and increased memory use while fragments are pending.
+ */
+#define IEEE80211_FRAGMENT_MAX 4
+
+struct ieee80211_fragment_entry {
+	struct sk_buff_head skb_list;
+	unsigned long first_frag_time;
+	u16 seq;
+	u16 extra_len;
+	u16 last_frag;
+	u8 rx_queue;
+	bool check_sequential_pn; /* needed for CCMP/GCMP */
+	u8 last_pn[6]; /* PN of the last fragment if CCMP was used */
+	unsigned int key_color;
+};
+
+struct ieee80211_fragment_cache {
+	struct ieee80211_fragment_entry	entries[IEEE80211_FRAGMENT_MAX];
+	unsigned int next;
+};
+
 /**
  * struct sta_info - STA information
  *
@@ -384,6 +411,7 @@ DECLARE_EWMA(signal, 1024, 8)
  * @tx_stats: TX statistics
  * @rx_stats: RX statistics
  * @status_stats: TX status statistics
+ * @frags: fragment cache
  */
 struct sta_info {
 	/* General information, mostly static */
@@ -493,6 +521,8 @@ struct sta_info {
 
 	struct cfg80211_chan_def tdls_chandef;
 
+	struct ieee80211_fragment_cache frags;
+
 	/* keep last! */
 	struct ieee80211_sta sta;
 };
-- 
cgit v1.2.3


From 608b0a2ae928a74a2f89e02227339dd79cdb63cf Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Mon, 31 May 2021 22:28:31 +0200
Subject: mac80211: check defrag PN against current frame

commit bf30ca922a0c0176007e074b0acc77ed345e9990 upstream.

As pointed out by Mathy Vanhoef, we implement the RX PN check
on fragmented frames incorrectly - we check against the last
received PN prior to the new frame, rather than to the one in
this frame itself.

Prior patches addressed the security issue here, but in order
to be able to reason better about the code, fix it to really
compare against the current frame's PN, not the last stored
one.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.bfbc340ff071.Id0b690e581da7d03d76df90bb0e3fd55930bc8a0@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/linux/ieee80211.h  | 10 ++++++++++
 net/mac80211/ieee80211_i.h | 11 +++++++++--
 net/mac80211/rx.c          |  5 ++---
 net/mac80211/wpa.c         | 12 ++++++++----
 4 files changed, 29 insertions(+), 9 deletions(-)

(limited to 'net/mac80211')

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index e7a278ca1fde..a5bbec4c176f 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -638,6 +638,16 @@ static inline bool ieee80211_is_first_frag(__le16 seq_ctrl)
 	return (seq_ctrl & cpu_to_le16(IEEE80211_SCTL_FRAG)) == 0;
 }
 
+/**
+ * ieee80211_is_frag - check if a frame is a fragment
+ * @hdr: 802.11 header of the frame
+ */
+static inline bool ieee80211_is_frag(struct ieee80211_hdr *hdr)
+{
+	return ieee80211_has_morefrags(hdr->frame_control) ||
+	       hdr->seq_ctrl & cpu_to_le16(IEEE80211_SCTL_FRAG);
+}
+
 struct ieee80211s_hdr {
 	u8 flags;
 	u8 ttl;
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 3f270fe15779..e293b2fbf855 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -218,8 +218,15 @@ struct ieee80211_rx_data {
 	 */
 	int security_idx;
 
-	u32 tkip_iv32;
-	u16 tkip_iv16;
+	union {
+		struct {
+			u32 iv32;
+			u16 iv16;
+		} tkip;
+		struct {
+			u8 pn[IEEE80211_CCMP_PN_LEN];
+		} ccm_gcm;
+	};
 };
 
 struct ieee80211_csa_settings {
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index a93dd83b77af..350b2035f37a 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1922,7 +1922,6 @@ 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 (!requires_sequential_pn(rx, fc))
 			return RX_DROP_UNUSABLE;
@@ -1937,8 +1936,8 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 			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);
diff --git a/net/mac80211/wpa.c b/net/mac80211/wpa.c
index cb439e06919f..921115327ec8 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -161,8 +161,8 @@ ieee80211_rx_h_michael_mic_verify(struct ieee80211_rx_data *rx)
 
 update_iv:
 	/* update IV in key information to be able to detect replays */
-	rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip_iv32;
-	rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip_iv16;
+	rx->key->u.tkip.rx[rx->security_idx].iv32 = rx->tkip.iv32;
+	rx->key->u.tkip.rx[rx->security_idx].iv16 = rx->tkip.iv16;
 
 	return RX_CONTINUE;
 
@@ -292,8 +292,8 @@ ieee80211_crypto_tkip_decrypt(struct ieee80211_rx_data *rx)
 					  key, skb->data + hdrlen,
 					  skb->len - hdrlen, rx->sta->sta.addr,
 					  hdr->addr1, hwaccel, rx->security_idx,
-					  &rx->tkip_iv32,
-					  &rx->tkip_iv16);
+					  &rx->tkip.iv32,
+					  &rx->tkip.iv16);
 	if (res != TKIP_DECRYPT_OK)
 		return RX_DROP_UNUSABLE;
 
@@ -553,6 +553,8 @@ ieee80211_crypto_ccmp_decrypt(struct ieee80211_rx_data *rx,
 		}
 
 		memcpy(key->u.ccmp.rx_pn[queue], pn, IEEE80211_CCMP_PN_LEN);
+		if (unlikely(ieee80211_is_frag(hdr)))
+			memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
 	}
 
 	/* Remove CCMP header and MIC */
@@ -784,6 +786,8 @@ ieee80211_crypto_gcmp_decrypt(struct ieee80211_rx_data *rx)
 		}
 
 		memcpy(key->u.gcmp.rx_pn[queue], pn, IEEE80211_GCMP_PN_LEN);
+		if (unlikely(ieee80211_is_frag(hdr)))
+			memcpy(rx->ccm_gcm.pn, pn, IEEE80211_CCMP_PN_LEN);
 	}
 
 	/* Remove GCMP header and MIC */
-- 
cgit v1.2.3


From c882f322aebcba8778677dd70916b48c04e144e8 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Mon, 31 May 2021 22:28:32 +0200
Subject: mac80211: prevent attacks on TKIP/WEP as well

commit 7e44a0b597f04e67eee8cdcbe7ee706c6f5de38b upstream.

Similar to the issues fixed in previous patches, TKIP and WEP
should be protected even if for TKIP we have the Michael MIC
protecting it, and WEP is broken anyway.

However, this also somewhat protects potential other algorithms
that drivers might implement.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.430e8c202313.Ia37e4e5b6b3eaab1a5ae050e015f6c92859dbe27@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/mac80211/rx.c       | 12 ++++++++++++
 net/mac80211/sta_info.h |  3 ++-
 2 files changed, 14 insertions(+), 1 deletion(-)

(limited to 'net/mac80211')

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 350b2035f37a..7f070b911b2a 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1888,6 +1888,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 			 * 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],
@@ -1900,6 +1901,9 @@ 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)) {
+			entry->is_protected = true;
+			entry->key_color = rx->key->color;
 		}
 		return RX_QUEUED;
 	}
@@ -1941,6 +1945,14 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 		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) ||
+		    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;
 	}
 
 	skb_pull(rx->skb, ieee80211_hdrlen(fc));
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 1b178cc42d3a..b2e5928b1f7b 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -341,7 +341,8 @@ struct ieee80211_fragment_entry {
 	u16 extra_len;
 	u16 last_frag;
 	u8 rx_queue;
-	bool check_sequential_pn; /* needed for CCMP/GCMP */
+	u8 check_sequential_pn:1, /* needed for CCMP/GCMP */
+	   is_protected:1;
 	u8 last_pn[6]; /* PN of the last fragment if CCMP was used */
 	unsigned int key_color;
 };
-- 
cgit v1.2.3


From e3d4030498c304d7c36bccc6acdedacf55402387 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Mon, 31 May 2021 22:28:33 +0200
Subject: mac80211: do not accept/forward invalid EAPOL frames

commit a8c4d76a8dd4fb9666fc8919a703d85fb8f44ed8 upstream.

EAPOL frames are used for authentication and key management between the
AP and each individual STA associated in the BSS. Those frames are not
supposed to be sent by one associated STA to another associated STA
(either unicast for broadcast/multicast).

Similarly, in 802.11 they're supposed to be sent to the authenticator
(AP) address.

Since it is possible for unexpected EAPOL frames to result in misbehavior
in supplicant implementations, it is better for the AP to not allow such
cases to be forwarded to other clients either directly, or indirectly if
the AP interface is part of a bridge.

Accept EAPOL (control port) frames only if they're transmitted to the
own address, or, due to interoperability concerns, to the PAE group
address.

Disable forwarding of EAPOL (or well, the configured control port
protocol) frames back to wireless medium in all cases. Previously, these
frames were accepted from fully authenticated and authorized stations
and also from unauthenticated stations for one of the cases.

Additionally, to avoid forwarding by the bridge, rewrite the PAE group
address case to the local MAC address.

Cc: stable@vger.kernel.org
Co-developed-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Link: https://lore.kernel.org/r/20210511200110.cb327ed0cabe.Ib7dcffa2a31f0913d660de65ba3c8aca75b1d10f@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/mac80211/rx.c | 34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

(limited to 'net/mac80211')

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 7f070b911b2a..1a7267448dc8 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2141,13 +2141,13 @@ 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))
@@ -2176,6 +2176,7 @@ 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)) {
 			/*
@@ -2228,9 +2229,30 @@ ieee80211_deliver_skb(struct ieee80211_rx_data *rx)
 #endif
 
 	if (skb) {
+		struct ethhdr *ehdr = (void *)skb_mac_header(skb);
+
 		/* deliver to local stack */
 		skb->protocol = eth_type_trans(skb, dev);
 		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);
+
 		if (rx->napi)
 			napi_gro_receive(rx->napi, skb);
 		else
-- 
cgit v1.2.3


From 6bc28ede7bf3fefd837210b6ba05c91983249796 Mon Sep 17 00:00:00 2001
From: Wen Gong <wgong@codeaurora.org>
Date: Mon, 31 May 2021 22:28:34 +0200
Subject: mac80211: extend protection against mixed key and fragment cache
 attacks

commit 3edc6b0d6c061a70d8ca3c3c72eb1f58ce29bfb1 upstream.

For some chips/drivers, e.g., QCA6174 with ath10k, the decryption is
done by the hardware, and the Protected bit in the Frame Control field
is cleared in the lower level driver before the frame is passed to
mac80211. In such cases, the condition for ieee80211_has_protected() is
not met in ieee80211_rx_h_defragment() of mac80211 and the new security
validation steps are not executed.

Extend mac80211 to cover the case where the Protected bit has been
cleared, but the frame is indicated as having been decrypted by the
hardware. This extends protection against mixed key and fragment cache
attack for additional drivers/chips. This fixes CVE-2020-24586 and
CVE-2020-24587 for such cases.

Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00110-QCARMSWP-1

Cc: stable@vger.kernel.org
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Link: https://lore.kernel.org/r/20210511200110.037aa5ca0390.I7bb888e2965a0db02a67075fcb5deb50eb7408aa@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/mac80211/rx.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

(limited to 'net/mac80211')

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 1a7267448dc8..ae0fba044cd0 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1842,7 +1842,7 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 	unsigned int frag, seq;
 	struct ieee80211_fragment_entry *entry;
 	struct sk_buff *skb;
-	struct ieee80211_rx_status *status;
+	struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
 
 	hdr = (struct ieee80211_hdr *)rx->skb->data;
 	fc = hdr->frame_control;
@@ -1901,7 +1901,9 @@ 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)) {
+		} else if (rx->key &&
+			   (ieee80211_has_protected(fc) ||
+			    (status->flag & RX_FLAG_DECRYPTED))) {
 			entry->is_protected = true;
 			entry->key_color = rx->key->color;
 		}
@@ -1946,13 +1948,19 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 			return RX_DROP_UNUSABLE;
 		memcpy(entry->last_pn, pn, IEEE80211_CCMP_PN_LEN);
 	} else if (entry->is_protected &&
-		   (!rx->key || !ieee80211_has_protected(fc) ||
+		   (!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));
-- 
cgit v1.2.3


From deb0f05255ad4478aae7964a1eb8a20893eb9bce Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Wed, 9 Jun 2021 16:13:06 +0200
Subject: mac80211: drop multicast fragments

[ Upstream commit a9799541ca34652d9996e45f80e8e03144c12949 ]

These are not permitted by the spec, just drop them.

Link: https://lore.kernel.org/r/20210609161305.23def022b750.Ibd6dd3cdce573dae262fcdc47f8ac52b883a9c50@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/mac80211/rx.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

(limited to 'net/mac80211')

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index ae0fba044cd0..bde924968cd2 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -1853,17 +1853,15 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 	sc = le16_to_cpu(hdr->seq_ctrl);
 	frag = sc & IEEE80211_SCTL_FRAG;
 
-	if (is_multicast_ether_addr(hdr->addr1)) {
-		I802_DEBUG_INC(rx->local->dot11MulticastReceivedFrameCount);
-		goto out_no_led;
-	}
-
 	if (rx->sta)
 		cache = &rx->sta->frags;
 
 	if (likely(!ieee80211_has_morefrags(fc) && frag == 0))
 		goto out;
 
+	if (is_multicast_ether_addr(hdr->addr1))
+		return RX_DROP_MONITOR;
+
 	I802_DEBUG_INC(rx->local->rx_handlers_fragments);
 
 	if (skb_linearize(rx->skb))
@@ -1992,7 +1990,6 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
 
  out:
 	ieee80211_led_rx(rx->local);
- out_no_led:
 	if (rx->sta)
 		rx->sta->rx_stats.packets++;
 	return RX_CONTINUE;
-- 
cgit v1.2.3