[PATCH 01/18] mac80211: assure all fragments are encrypted

[PATCH 01/18] mac80211: assure all fragments are encrypted

[Johannes Berg]

From: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>

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>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/rx.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 62047e93e217..65fc674e27cc 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2194,6 +2194,16 @@ 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)
 {
@@ -2238,12 +2248,7 @@ 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
@@ -2285,11 +2290,7 @@ 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--) {
-- 
2.30.2

[PATCH 02/18] mac80211: prevent mixed key and fragment cache attacks

[Johannes Berg]

From: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>

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>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 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(+)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 8fcbaa1eedf3..874ffe7819e5 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -97,6 +97,7 @@ 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 56c068cb49c4..f695fc80088b 100644
--- a/net/mac80211/key.c
+++ b/net/mac80211/key.c
@@ -799,6 +799,7 @@ 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;
@@ -850,6 +851,12 @@ 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);
 
 	ret = ieee80211_key_replace(sdata, sta, pairwise, old_key, key);
diff --git a/net/mac80211/key.h b/net/mac80211/key.h
index 7ad72e9b4991..1e326c89d721 100644
--- a/net/mac80211/key.h
+++ b/net/mac80211/key.h
@@ -128,6 +128,8 @@ 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 65fc674e27cc..531232b91bc4 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2255,6 +2255,7 @@ 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);
@@ -2292,6 +2293,11 @@ 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]++;
-- 
2.30.2

[PATCH 03/18] mac80211: properly handle A-MSDUs that start with an RFC 1042 header

[Johannes Berg]

From: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>

Properly parse A-MSDUs whose first 6 bytes happen to equal a rfc1042
header. This can occur in practice when the destination MAC address
equals AA:AA:03:00:00:00. More importantly, this simplifies the next
patch to mitigate A-MSDU injection attacks.

Cc: stable@vger.kernel.org
Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 include/net/cfg80211.h | 4 ++--
 net/mac80211/rx.c      | 2 +-
 net/wireless/util.c    | 4 ++--
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 5224f885a99a..58c2cd417e89 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -5760,7 +5760,7 @@ unsigned int ieee80211_get_mesh_hdrlen(struct ieee80211s_hdr *meshhdr);
  */
 int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
 				  const u8 *addr, enum nl80211_iftype iftype,
-				  u8 data_offset);
+				  u8 data_offset, bool is_amsdu);
 
 /**
  * ieee80211_data_to_8023 - convert an 802.11 data frame to 802.3
@@ -5772,7 +5772,7 @@ int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
 static inline int ieee80211_data_to_8023(struct sk_buff *skb, const u8 *addr,
 					 enum nl80211_iftype iftype)
 {
-	return ieee80211_data_to_8023_exthdr(skb, NULL, addr, iftype, 0);
+	return ieee80211_data_to_8023_exthdr(skb, NULL, addr, iftype, 0, false);
 }
 
 /**
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 531232b91bc4..f14d32a5001d 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2682,7 +2682,7 @@ __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,
diff --git a/net/wireless/util.c b/net/wireless/util.c
index 382c5262d997..39966a873e40 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -542,7 +542,7 @@ EXPORT_SYMBOL(ieee80211_get_mesh_hdrlen);
 
 int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
 				  const u8 *addr, enum nl80211_iftype iftype,
-				  u8 data_offset)
+				  u8 data_offset, bool is_amsdu)
 {
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 	struct {
@@ -629,7 +629,7 @@ int ieee80211_data_to_8023_exthdr(struct sk_buff *skb, struct ethhdr *ehdr,
 	skb_copy_bits(skb, hdrlen, &payload, sizeof(payload));
 	tmp.h_proto = payload.proto;
 
-	if (likely((ether_addr_equal(payload.hdr, rfc1042_header) &&
+	if (likely((!is_amsdu && ether_addr_equal(payload.hdr, rfc1042_header) &&
 		    tmp.h_proto != htons(ETH_P_AARP) &&
 		    tmp.h_proto != htons(ETH_P_IPX)) ||
 		   ether_addr_equal(payload.hdr, bridge_tunnel_header)))
-- 
2.30.2

[PATCH 04/18] cfg80211: mitigate A-MSDU aggregation attacks

[Johannes Berg]

From: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>

Mitigate A-MSDU injection attacks (CVE-2020-24588) by detecting if the
destination address of a subframe equals an RFC1042 (i.e., LLC/SNAP)
header, and if so dropping the complete A-MSDU frame. This mitigates
known attacks, although new (unknown) aggregation-based attacks may
remain possible.

This defense works because in A-MSDU aggregation injection attacks, a
normal encrypted Wi-Fi frame is turned into an A-MSDU frame. This means
the first 6 bytes of the first A-MSDU subframe correspond to an RFC1042
header. In other words, the destination MAC address of the first A-MSDU
subframe contains the start of an RFC1042 header during an aggregation
attack. We can detect this and thereby prevent this specific attack.
For details, see Section 7.2 of "Fragment and Forge: Breaking Wi-Fi
Through Frame Aggregation and Fragmentation".

Note that for kernel 4.9 and above this patch depends on "mac80211:
properly handle A-MSDUs that start with a rfc1042 header". Otherwise
this patch has no impact and attacks will remain possible.

Cc: stable@vger.kernel.org
Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/wireless/util.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/wireless/util.c b/net/wireless/util.c
index 39966a873e40..7ec021a610ae 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -771,6 +771,9 @@ void ieee80211_amsdu_to_8023s(struct sk_buff *skb, struct sk_buff_head *list,
 		remaining = skb->len - offset;
 		if (subframe_len > remaining)
 			goto purge;
+		/* mitigate A-MSDU aggregation injection attacks */
+		if (ether_addr_equal(eth.h_dest, rfc1042_header))
+			goto purge;
 
 		offset += sizeof(struct ethhdr);
 		last = remaining <= subframe_len + padding;
-- 
2.30.2

[PATCH 05/18] mac80211: drop A-MSDUs on old ciphers

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

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
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/rx.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index f14d32a5001d..8a72d48ad6e0 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>
@@ -2739,6 +2739,23 @@ 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);
 }
 
-- 
2.30.2

[PATCH 06/18] mac80211: add fragment cache to sta_info

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

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
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/ieee80211_i.h | 26 ++++--------------------
 net/mac80211/iface.c       | 11 +++-------
 net/mac80211/rx.c          | 41 ++++++++++++++++++++++++++++----------
 net/mac80211/sta_info.c    |  6 +++++-
 net/mac80211/sta_info.h    | 32 ++++++++++++++++++++++++++++-
 5 files changed, 73 insertions(+), 43 deletions(-)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 874ffe7819e5..4c714375bad0 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -50,12 +50,6 @@ 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
 
@@ -88,19 +82,6 @@ extern const u8 ieee80211_ac_to_qos_mask[IEEE80211_NUM_ACS];
 
 #define IEEE80211_MAX_NAN_INSTANCE_ID 255
 
-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;
 
@@ -903,9 +884,7 @@ 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;
@@ -2321,4 +2300,7 @@ u32 ieee80211_calc_expected_tx_airtime(struct ieee80211_hw *hw,
 #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 7032a2b59249..2e2f73a4aa73 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -8,7 +8,7 @@
  * Copyright 2008, Johannes Berg <johannes@sipsolutions.net>
  * Copyright 2013-2014  Intel Mobile Communications GmbH
  * Copyright (c) 2016        Intel Deutschland GmbH
- * Copyright (C) 2018-2020 Intel Corporation
+ * Copyright (C) 2018-2021 Intel Corporation
  */
 #include <linux/slab.h>
 #include <linux/kernel.h>
@@ -677,16 +677,12 @@ 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))
 		ieee80211_mesh_teardown_sdata(sdata);
@@ -1930,8 +1926,7 @@ 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 8a72d48ad6e0..7212a1bebd0c 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -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)
@@ -2207,6 +2222,7 @@ 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;
@@ -2228,6 +2244,9 @@ 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;
 
@@ -2246,7 +2265,7 @@ 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;
@@ -2274,7 +2293,7 @@ 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 ec6973ee88ef..f2fb69da9b6e 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -4,7 +4,7 @@
  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
  * 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/module.h>
@@ -392,6 +392,8 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
 
 	u64_stats_init(&sta->rx_stats.syncp);
 
+	ieee80211_init_frag_cache(&sta->frags);
+
 	sta->sta_state = IEEE80211_STA_NONE;
 
 	/* Mark TID as unreserved */
@@ -1102,6 +1104,8 @@ static void __sta_info_destroy_part2(struct sta_info *sta)
 
 	ieee80211_sta_debugfs_remove(sta);
 
+	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 78b9d0c7cc58..5c56d29a619e 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -3,7 +3,7 @@
  * Copyright 2002-2005, Devicescape Software, Inc.
  * Copyright 2013-2014  Intel Mobile Communications GmbH
  * Copyright(c) 2015-2017 Intel Deutschland GmbH
- * Copyright(c) 2020 Intel Corporation
+ * Copyright(c) 2020-2021 Intel Corporation
  */
 
 #ifndef STA_INFO_H
@@ -438,6 +438,33 @@ struct ieee80211_sta_rx_stats {
 	u64 msdu[IEEE80211_NUM_TIDS + 1];
 };
 
+/*
+ * 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;
+};
+
 /*
  * The bandwidth threshold below which the per-station CoDel parameters will be
  * scaled to be more lenient (to prevent starvation of slow stations). This
@@ -531,6 +558,7 @@ struct ieee80211_sta_rx_stats {
  * @status_stats.last_ack_signal: last ACK signal
  * @status_stats.ack_signal_filled: last ACK signal validity
  * @status_stats.avg_ack_signal: average ACK signal
+ * @frags: fragment cache
  */
 struct sta_info {
 	/* General information, mostly static */
@@ -639,6 +667,8 @@ struct sta_info {
 
 	struct cfg80211_chan_def tdls_chandef;
 
+	struct ieee80211_fragment_cache frags;
+
 	/* keep last! */
 	struct ieee80211_sta sta;
 };
-- 
2.30.2

[PATCH 07/18] mac80211: check defrag PN against current frame

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

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
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/ieee80211_i.h | 11 +++++++++--
 net/mac80211/rx.c          |  5 ++---
 net/mac80211/wpa.c         | 13 +++++++++----
 3 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 4c714375bad0..214404a558fb 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -223,8 +223,15 @@ 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 7212a1bebd0c..b619c47e1d12 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2308,7 +2308,6 @@ 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;
@@ -2323,8 +2322,8 @@ 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 91bf32af55e9..bca47fad5a16 100644
--- a/net/mac80211/wpa.c
+++ b/net/mac80211/wpa.c
@@ -3,6 +3,7 @@
  * Copyright 2002-2004, Instant802 Networks, Inc.
  * Copyright 2008, Jouni Malinen <j@w1.fi>
  * Copyright (C) 2016-2017 Intel Deutschland GmbH
+ * Copyright (C) 2020-2021 Intel Corporation
  */
 
 #include <linux/netdevice.h>
@@ -167,8 +168,8 @@ 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;
 
@@ -294,8 +295,8 @@ 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 +554,8 @@ 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 */
@@ -781,6 +784,8 @@ 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 */
-- 
2.30.2

[PATCH 08/18] mac80211: prevent attacks on TKIP/WEP as well

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

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
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/rx.c       | 12 ++++++++++++
 net/mac80211/sta_info.h |  3 ++-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index b619c47e1d12..4454ec47283f 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2274,6 +2274,7 @@ 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],
@@ -2286,6 +2287,9 @@ 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;
 	}
@@ -2327,6 +2331,14 @@ 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 5c56d29a619e..0333072ebd98 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -455,7 +455,8 @@ 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;
 };
-- 
2.30.2

[PATCH 09/18] mac80211: do not accept/forward invalid EAPOL frames

[Johannes Berg]

From: Johannes Berg <johannes.berg@intel.com>

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>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/rx.c | 33 +++++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 4454ec47283f..22a925899a9e 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2531,13 +2531,13 @@ 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))
@@ -2562,8 +2562,28 @@ 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);
@@ -2603,6 +2623,7 @@ 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) {
-- 
2.30.2

[PATCH 10/18] mac80211: extend protection against mixed key and fragment cache attacks

[Johannes Berg]

From: Wen Gong <wgong@codeaurora.org>

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>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 net/mac80211/rx.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 22a925899a9e..1bb43edd47b6 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -2229,6 +2229,7 @@ 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 = IEEE80211_SKB_RXCB(rx->skb);
 
 	hdr = (struct ieee80211_hdr *)rx->skb->data;
 	fc = hdr->frame_control;
@@ -2287,7 +2288,9 @@ 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;
 		}
@@ -2332,13 +2335,19 @@ 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));
-- 
2.30.2

[PATCH 11/18] ath10k: add CCMP PN replay protection for fragmented frames for PCIe

[Johannes Berg]

From: Wen Gong <wgong@codeaurora.org>

PN replay check for not fragmented frames is finished in the firmware,
but this was not done for fragmented frames when ath10k is used with
QCA6174/QCA6377 PCIe. mac80211 has the function
ieee80211_rx_h_defragment() for PN replay check for fragmented frames,
but this does not get checked with QCA6174 due to the
ieee80211_has_protected() condition not matching the cleared Protected
bit case.

Validate the PN of received fragmented frames within ath10k when CCMP is
used and drop the fragment if the PN is not correct (incremented by
exactly one from the previous fragment). This applies only for
QCA6174/QCA6377 PCIe.

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>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 drivers/net/wireless/ath/ath10k/htt.h    |  1 +
 drivers/net/wireless/ath/ath10k/htt_rx.c | 99 +++++++++++++++++++++++-
 2 files changed, 96 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/htt.h b/drivers/net/wireless/ath/ath10k/htt.h
index 956157946106..dbc8aef82a65 100644
--- a/drivers/net/wireless/ath/ath10k/htt.h
+++ b/drivers/net/wireless/ath/ath10k/htt.h
@@ -845,6 +845,7 @@ enum htt_security_types {
 
 #define ATH10K_HTT_TXRX_PEER_SECURITY_MAX 2
 #define ATH10K_TXRX_NUM_EXT_TIDS 19
+#define ATH10K_TXRX_NON_QOS_TID 16
 
 enum htt_security_flags {
 #define HTT_SECURITY_TYPE_MASK 0x7F
diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index 1a08156d5011..f1e5bce8b14f 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -1746,16 +1746,87 @@ static void ath10k_htt_rx_h_csum_offload(struct sk_buff *msdu)
 	msdu->ip_summed = ath10k_htt_rx_get_csum_state(msdu);
 }
 
+static u64 ath10k_htt_rx_h_get_pn(struct ath10k *ar, struct sk_buff *skb,
+				  u16 offset,
+				  enum htt_rx_mpdu_encrypt_type enctype)
+{
+	struct ieee80211_hdr *hdr;
+	u64 pn = 0;
+	u8 *ehdr;
+
+	hdr = (struct ieee80211_hdr *)(skb->data + offset);
+	ehdr = skb->data + offset + ieee80211_hdrlen(hdr->frame_control);
+
+	if (enctype == HTT_RX_MPDU_ENCRYPT_AES_CCM_WPA2) {
+		pn = ehdr[0];
+		pn |= (u64)ehdr[1] << 8;
+		pn |= (u64)ehdr[4] << 16;
+		pn |= (u64)ehdr[5] << 24;
+		pn |= (u64)ehdr[6] << 32;
+		pn |= (u64)ehdr[7] << 40;
+	}
+	return pn;
+}
+
+static bool ath10k_htt_rx_h_frag_pn_check(struct ath10k *ar,
+					  struct sk_buff *skb,
+					  u16 peer_id,
+					  u16 offset,
+					  enum htt_rx_mpdu_encrypt_type enctype)
+{
+	struct ath10k_peer *peer;
+	union htt_rx_pn_t *last_pn, new_pn = {0};
+	struct ieee80211_hdr *hdr;
+	bool more_frags;
+	u8 tid, frag_number;
+	u32 seq;
+
+	peer = ath10k_peer_find_by_id(ar, peer_id);
+	if (!peer) {
+		ath10k_dbg(ar, ATH10K_DBG_HTT, "invalid peer for frag pn check\n");
+		return false;
+	}
+
+	hdr = (struct ieee80211_hdr *)(skb->data + offset);
+	if (ieee80211_is_data_qos(hdr->frame_control))
+		tid = ieee80211_get_tid(hdr);
+	else
+		tid = ATH10K_TXRX_NON_QOS_TID;
+
+	last_pn = &peer->frag_tids_last_pn[tid];
+	new_pn.pn48 = ath10k_htt_rx_h_get_pn(ar, skb, offset, enctype);
+	more_frags = ieee80211_has_morefrags(hdr->frame_control);
+	frag_number = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG;
+	seq = (__le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_SEQ) >> 4;
+
+	if (frag_number == 0) {
+		last_pn->pn48 = new_pn.pn48;
+		peer->frag_tids_seq[tid] = seq;
+	} else {
+		if (seq != peer->frag_tids_seq[tid])
+			return false;
+
+		if (new_pn.pn48 != last_pn->pn48 + 1)
+			return false;
+
+		last_pn->pn48 = new_pn.pn48;
+	}
+
+	return true;
+}
+
 static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
 				 struct sk_buff_head *amsdu,
 				 struct ieee80211_rx_status *status,
 				 bool fill_crypt_header,
 				 u8 *rx_hdr,
-				 enum ath10k_pkt_rx_err *err)
+				 enum ath10k_pkt_rx_err *err,
+				 u16 peer_id,
+				 bool frag)
 {
 	struct sk_buff *first;
 	struct sk_buff *last;
-	struct sk_buff *msdu;
+	struct sk_buff *msdu, *temp;
 	struct htt_rx_desc *rxd;
 	struct ieee80211_hdr *hdr;
 	enum htt_rx_mpdu_encrypt_type enctype;
@@ -1768,6 +1839,7 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
 	bool is_decrypted;
 	bool is_mgmt;
 	u32 attention;
+	bool frag_pn_check = true;
 
 	if (skb_queue_empty(amsdu))
 		return;
@@ -1866,6 +1938,24 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
 	}
 
 	skb_queue_walk(amsdu, msdu) {
+		if (frag && !fill_crypt_header && is_decrypted &&
+		    enctype == HTT_RX_MPDU_ENCRYPT_AES_CCM_WPA2)
+			frag_pn_check = ath10k_htt_rx_h_frag_pn_check(ar,
+								      msdu,
+								      peer_id,
+								      0,
+								      enctype);
+
+		if (!frag_pn_check) {
+			/* Discard the fragment with invalid PN */
+			temp = msdu->prev;
+			__skb_unlink(msdu, amsdu);
+			dev_kfree_skb_any(msdu);
+			msdu = temp;
+			frag_pn_check = true;
+			continue;
+		}
+
 		ath10k_htt_rx_h_csum_offload(msdu);
 		ath10k_htt_rx_h_undecap(ar, msdu, status, first_hdr, enctype,
 					is_decrypted);
@@ -2071,7 +2161,8 @@ static int ath10k_htt_rx_handle_amsdu(struct ath10k_htt *htt)
 		ath10k_htt_rx_h_unchain(ar, &amsdu, &drop_cnt, &unchain_cnt);
 
 	ath10k_htt_rx_h_filter(ar, &amsdu, rx_status, &drop_cnt_filter);
-	ath10k_htt_rx_h_mpdu(ar, &amsdu, rx_status, true, first_hdr, &err);
+	ath10k_htt_rx_h_mpdu(ar, &amsdu, rx_status, true, first_hdr, &err, 0,
+			     false);
 	msdus_to_queue = skb_queue_len(&amsdu);
 	ath10k_htt_rx_h_enqueue(ar, &amsdu, rx_status);
 
@@ -3027,7 +3118,7 @@ static int ath10k_htt_rx_in_ord_ind(struct ath10k *ar, struct sk_buff *skb)
 			ath10k_htt_rx_h_ppdu(ar, &amsdu, status, vdev_id);
 			ath10k_htt_rx_h_filter(ar, &amsdu, status, NULL);
 			ath10k_htt_rx_h_mpdu(ar, &amsdu, status, false, NULL,
-					     NULL);
+					     NULL, peer_id, frag);
 			ath10k_htt_rx_h_enqueue(ar, &amsdu, status);
 			break;
 		case -EAGAIN:
-- 
2.30.2

Re: [PATCH 11/18] ath10k: add CCMP PN replay protection for fragmented frames for PCIe

[Abhishek Kumar]

> +static bool ath10k_htt_rx_h_frag_pn_check(struct ath10k *ar,
> +                                         struct sk_buff *skb,
> +                                         u16 peer_id,
> +                                         u16 offset,
> +                                         enum htt_rx_mpdu_encrypt_type enctype)
> +{
> +       struct ath10k_peer *peer;
> +       union htt_rx_pn_t *last_pn, new_pn = {0};
> +       struct ieee80211_hdr *hdr;
> +       bool more_frags;
The variable more_frags is not getting used.
> +       new_pn.pn48 = ath10k_htt_rx_h_get_pn(ar, skb, offset, enctype);
> +       more_frags = ieee80211_has_morefrags(hdr->frame_control);
"more_frags is assigned here but not used anywhere.

I have raised a patch for remove this, I have raised a patch for this,
https://patchwork.kernel.org/project/linux-wireless/patch/20210514220644.1.Iad576de95836b74aba80a5fc28d7131940eca190@changeid/

-Abhishek

[PATCH 12/18] ath10k: drop fragments with multicast DA for PCIe

[Johannes Berg]

From: Wen Gong <wgong@codeaurora.org>

Fragmentation is not used with multicast frames. Discard unexpected
fragments with multicast DA. This fixes CVE-2020-26145.

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>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 drivers/net/wireless/ath/ath10k/htt_rx.c | 23 ++++++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index f1e5bce8b14f..cb04848ed5cb 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -1768,6 +1768,16 @@ static u64 ath10k_htt_rx_h_get_pn(struct ath10k *ar, struct sk_buff *skb,
 	return pn;
 }
 
+static bool ath10k_htt_rx_h_frag_multicast_check(struct ath10k *ar,
+						 struct sk_buff *skb,
+						 u16 offset)
+{
+	struct ieee80211_hdr *hdr;
+
+	hdr = (struct ieee80211_hdr *)(skb->data + offset);
+	return !is_multicast_ether_addr(hdr->addr1);
+}
+
 static bool ath10k_htt_rx_h_frag_pn_check(struct ath10k *ar,
 					  struct sk_buff *skb,
 					  u16 peer_id,
@@ -1839,7 +1849,7 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
 	bool is_decrypted;
 	bool is_mgmt;
 	u32 attention;
-	bool frag_pn_check = true;
+	bool frag_pn_check = true, multicast_check = true;
 
 	if (skb_queue_empty(amsdu))
 		return;
@@ -1946,13 +1956,20 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
 								      0,
 								      enctype);
 
-		if (!frag_pn_check) {
-			/* Discard the fragment with invalid PN */
+		if (frag)
+			multicast_check = ath10k_htt_rx_h_frag_multicast_check(ar,
+									       msdu,
+									       0);
+
+		if (!frag_pn_check || !multicast_check) {
+			/* Discard the fragment with invalid PN or multicast DA
+			 */
 			temp = msdu->prev;
 			__skb_unlink(msdu, amsdu);
 			dev_kfree_skb_any(msdu);
 			msdu = temp;
 			frag_pn_check = true;
+			multicast_check = true;
 			continue;
 		}
 
-- 
2.30.2

[PATCH 13/18] ath10k: drop fragments with multicast DA for SDIO

[Johannes Berg]

From: Wen Gong <wgong@codeaurora.org>

Fragmentation is not used with multicast frames. Discard unexpected
fragments with multicast DA. This fixes CVE-2020-26145.

Tested-on: QCA6174 hw3.2 SDIO WLAN.RMH.4.4.1-00049

Cc: stable@vger.kernel.org
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 drivers/net/wireless/ath/ath10k/htt_rx.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index cb04848ed5cb..b1d93ff5215a 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -2617,6 +2617,13 @@ static bool ath10k_htt_rx_proc_rx_frag_ind_hl(struct ath10k_htt *htt,
 	rx_desc = (struct htt_hl_rx_desc *)(skb->data + tot_hdr_len);
 	rx_desc_info = __le32_to_cpu(rx_desc->info);
 
+	hdr = (struct ieee80211_hdr *)((u8 *)rx_desc + rx_hl->fw_desc.len);
+
+	if (is_multicast_ether_addr(hdr->addr1)) {
+		/* Discard the fragment with multicast DA */
+		goto err;
+	}
+
 	if (!MS(rx_desc_info, HTT_RX_DESC_HL_INFO_ENCRYPTED)) {
 		spin_unlock_bh(&ar->data_lock);
 		return ath10k_htt_rx_proc_rx_ind_hl(htt, &resp->rx_ind_hl, skb,
@@ -2624,8 +2631,6 @@ static bool ath10k_htt_rx_proc_rx_frag_ind_hl(struct ath10k_htt *htt,
 						    HTT_RX_NON_TKIP_MIC);
 	}
 
-	hdr = (struct ieee80211_hdr *)((u8 *)rx_desc + rx_hl->fw_desc.len);
-
 	if (ieee80211_has_retry(hdr->frame_control))
 		goto err;
 
-- 
2.30.2

[PATCH 14/18] ath10k: drop MPDU which has discard flag set by firmware for SDIO

[Johannes Berg]

From: Wen Gong <wgong@codeaurora.org>

When the discard flag is set by the firmware for an MPDU, it should be
dropped. This allows a mitigation for CVE-2020-24588 to be implemented
in the firmware.

Tested-on: QCA6174 hw3.2 SDIO WLAN.RMH.4.4.1-00049

Cc: stable@vger.kernel.org
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 drivers/net/wireless/ath/ath10k/htt_rx.c  |  5 +++++
 drivers/net/wireless/ath/ath10k/rx_desc.h | 14 +++++++++++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index b1d93ff5215a..12451ab66a19 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -2312,6 +2312,11 @@ static bool ath10k_htt_rx_proc_rx_ind_hl(struct ath10k_htt *htt,
 	fw_desc = &rx->fw_desc;
 	rx_desc_len = fw_desc->len;
 
+	if (fw_desc->u.bits.discard) {
+		ath10k_dbg(ar, ATH10K_DBG_HTT, "htt discard mpdu\n");
+		goto err;
+	}
+
 	/* I have not yet seen any case where num_mpdu_ranges > 1.
 	 * qcacld does not seem handle that case either, so we introduce the
 	 * same limitiation here as well.
diff --git a/drivers/net/wireless/ath/ath10k/rx_desc.h b/drivers/net/wireless/ath/ath10k/rx_desc.h
index f2b6bf8f0d60..705b6295e466 100644
--- a/drivers/net/wireless/ath/ath10k/rx_desc.h
+++ b/drivers/net/wireless/ath/ath10k/rx_desc.h
@@ -1282,7 +1282,19 @@ struct fw_rx_desc_base {
 #define FW_RX_DESC_UDP              (1 << 6)
 
 struct fw_rx_desc_hl {
-	u8 info0;
+	union {
+		struct {
+		u8 discard:1,
+		   forward:1,
+		   any_err:1,
+		   dup_err:1,
+		   reserved:1,
+		   inspect:1,
+		   extension:2;
+		} bits;
+		u8 info0;
+	} u;
+
 	u8 version;
 	u8 len;
 	u8 flags;
-- 
2.30.2

Re: [PATCH 14/18] ath10k: drop MPDU which has discard flag set by firmware for SDIO

[Brian Norris]

On Tue, May 11, 2021 at 11:03 AM Johannes Berg
<johannes@sipsolutions.net> wrote:
> --- a/drivers/net/wireless/ath/ath10k/htt_rx.c
> +++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
> @@ -2312,6 +2312,11 @@ static bool ath10k_htt_rx_proc_rx_ind_hl(struct ath10k_htt *htt,
>         fw_desc = &rx->fw_desc;
>         rx_desc_len = fw_desc->len;
>
> +       if (fw_desc->u.bits.discard) {
> +               ath10k_dbg(ar, ATH10K_DBG_HTT, "htt discard mpdu\n");
> +               goto err;
> +       }
> +
>         /* I have not yet seen any case where num_mpdu_ranges > 1.
>          * qcacld does not seem handle that case either, so we introduce the
>          * same limitiation here as well.
> diff --git a/drivers/net/wireless/ath/ath10k/rx_desc.h b/drivers/net/wireless/ath/ath10k/rx_desc.h
> index f2b6bf8f0d60..705b6295e466 100644
> --- a/drivers/net/wireless/ath/ath10k/rx_desc.h
> +++ b/drivers/net/wireless/ath/ath10k/rx_desc.h
> @@ -1282,7 +1282,19 @@ struct fw_rx_desc_base {
>  #define FW_RX_DESC_UDP              (1 << 6)
>
>  struct fw_rx_desc_hl {
> -       u8 info0;
> +       union {
> +               struct {
> +               u8 discard:1,
> +                  forward:1,
> +                  any_err:1,
> +                  dup_err:1,
> +                  reserved:1,
> +                  inspect:1,
> +                  extension:2;
> +               } bits;
> +               u8 info0;
> +       } u;

Am I misled here, or are you introducing endianness issues here? From C99:

"The order of allocation of bit-fields within a unit (high-order to
low-order or low-order to high-order) is implementation-defined."

Now, we're pretty well attuned to two implementations (big and little
endian), and this should work for the most common one (little endian),
but it's not wise to assume everyone is little endian.

Brian

Re: [PATCH 14/18] ath10k: drop MPDU which has discard flag set by firmware for SDIO

[Jeff Johnson]

On 2021-05-12 11:35, Brian Norris wrote:
> On Tue, May 11, 2021 at 11:03 AM Johannes Berg
> <johannes@sipsolutions.net> wrote:
>> --- a/drivers/net/wireless/ath/ath10k/htt_rx.c
>> +++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
>> @@ -2312,6 +2312,11 @@ static bool ath10k_htt_rx_proc_rx_ind_hl(struct
>> ath10k_htt *htt,
>>         fw_desc = &rx->fw_desc;
>>         rx_desc_len = fw_desc->len;
>> 
>> +       if (fw_desc->u.bits.discard) {
>> +               ath10k_dbg(ar, ATH10K_DBG_HTT, "htt discard mpdu\n");
>> +               goto err;
>> +       }
>> +
>>         /* I have not yet seen any case where num_mpdu_ranges > 1.
>>          * qcacld does not seem handle that case either, so we 
>> introduce
>> the
>>          * same limitiation here as well.
>> diff --git a/drivers/net/wireless/ath/ath10k/rx_desc.h
>> b/drivers/net/wireless/ath/ath10k/rx_desc.h
>> index f2b6bf8f0d60..705b6295e466 100644
>> --- a/drivers/net/wireless/ath/ath10k/rx_desc.h
>> +++ b/drivers/net/wireless/ath/ath10k/rx_desc.h
>> @@ -1282,7 +1282,19 @@ struct fw_rx_desc_base {
>>  #define FW_RX_DESC_UDP              (1 << 6)
>> 
>>  struct fw_rx_desc_hl {
>> -       u8 info0;
>> +       union {
>> +               struct {
>> +               u8 discard:1,
>> +                  forward:1,
>> +                  any_err:1,
>> +                  dup_err:1,
>> +                  reserved:1,
>> +                  inspect:1,
>> +                  extension:2;
>> +               } bits;
>> +               u8 info0;
>> +       } u;
> 
> Am I misled here, or are you introducing endianness issues here? From 
> C99:
> 
> "The order of allocation of bit-fields within a unit (high-order to
> low-order or low-order to high-order) is implementation-defined."
> 
> Now, we're pretty well attuned to two implementations (big and little
> endian), and this should work for the most common one (little endian),
> but it's not wise to assume everyone is little endian.
> 
> Brian

This issue was identified in internal review, but due to the embargo 
expiring
we sent it out as-is since that is what had been tested. The author will 
have
a follow-up change to replace this.

-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
Forum,
a Linux Foundation Collaborative Project

[PATCH 15/18] ath10k: Fix TKIP Michael MIC verification for PCIe

[Johannes Berg]

From: Wen Gong <wgong@codeaurora.org>

TKIP Michael MIC was not verified properly for PCIe cases since the
validation steps in ieee80211_rx_h_michael_mic_verify() in mac80211 did
not get fully executed due to unexpected flag values in
ieee80211_rx_status.

Fix this by setting the flags property to meet mac80211 expectations for
performing Michael MIC validation there. This fixes CVE-2020-26141. It
does the same as ath10k_htt_rx_proc_rx_ind_hl() for SDIO which passed
MIC verification case. This applies only to QCA6174/QCA9377 PCIe.

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>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 drivers/net/wireless/ath/ath10k/htt_rx.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index 12451ab66a19..87196f9bbdea 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -1974,6 +1974,11 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
 		}
 
 		ath10k_htt_rx_h_csum_offload(msdu);
+
+		if (frag && !fill_crypt_header &&
+		    enctype == HTT_RX_MPDU_ENCRYPT_TKIP_WPA)
+			status->flag &= ~RX_FLAG_MMIC_STRIPPED;
+
 		ath10k_htt_rx_h_undecap(ar, msdu, status, first_hdr, enctype,
 					is_decrypted);
 
@@ -1991,6 +1996,11 @@ static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
 
 		hdr = (void *)msdu->data;
 		hdr->frame_control &= ~__cpu_to_le16(IEEE80211_FCTL_PROTECTED);
+
+		if (frag && !fill_crypt_header &&
+		    enctype == HTT_RX_MPDU_ENCRYPT_TKIP_WPA)
+			status->flag &= ~RX_FLAG_IV_STRIPPED &
+					~RX_FLAG_MMIC_STRIPPED;
 	}
 }
 
-- 
2.30.2

[PATCH 16/18] ath10k: Validate first subframe of A-MSDU before processing the list

[Johannes Berg]

From: Sriram R <srirrama@codeaurora.org>

In certain scenarios a normal MSDU can be received as an A-MSDU when
the A-MSDU present bit of a QoS header gets flipped during reception.
Since this bit is unauthenticated, the hardware crypto engine can pass
the frame to the driver without any error indication.

This could result in processing unintended subframes collected in the
A-MSDU list. Hence, validate A-MSDU list by checking if the first frame
has a valid subframe header.

Comparing the non-aggregated MSDU and an A-MSDU, the fields of the first
subframe DA matches the LLC/SNAP header fields of a normal MSDU.
In order to avoid processing such frames, add a validation to
filter such A-MSDU frames where the first subframe header DA matches
with the LLC/SNAP header pattern.

Tested-on: QCA9984 hw1.0 PCI 10.4-3.10-00047

Cc: stable@vger.kernel.org
Signed-off-by: Sriram R <srirrama@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 drivers/net/wireless/ath/ath10k/htt_rx.c | 61 ++++++++++++++++++++++--
 1 file changed, 57 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath10k/htt_rx.c b/drivers/net/wireless/ath/ath10k/htt_rx.c
index 87196f9bbdea..7ffb5d5b2a70 100644
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -2108,14 +2108,62 @@ static void ath10k_htt_rx_h_unchain(struct ath10k *ar,
 	ath10k_unchain_msdu(amsdu, unchain_cnt);
 }
 
+static bool ath10k_htt_rx_validate_amsdu(struct ath10k *ar,
+					 struct sk_buff_head *amsdu)
+{
+	u8 *subframe_hdr;
+	struct sk_buff *first;
+	bool is_first, is_last;
+	struct htt_rx_desc *rxd;
+	struct ieee80211_hdr *hdr;
+	size_t hdr_len, crypto_len;
+	enum htt_rx_mpdu_encrypt_type enctype;
+	int bytes_aligned = ar->hw_params.decap_align_bytes;
+
+	first = skb_peek(amsdu);
+
+	rxd = (void *)first->data - sizeof(*rxd);
+	hdr = (void *)rxd->rx_hdr_status;
+
+	is_first = !!(rxd->msdu_end.common.info0 &
+		      __cpu_to_le32(RX_MSDU_END_INFO0_FIRST_MSDU));
+	is_last = !!(rxd->msdu_end.common.info0 &
+		     __cpu_to_le32(RX_MSDU_END_INFO0_LAST_MSDU));
+
+	/* Return in case of non-aggregated msdu */
+	if (is_first && is_last)
+		return true;
+
+	/* First msdu flag is not set for the first msdu of the list */
+	if (!is_first)
+		return false;
+
+	enctype = MS(__le32_to_cpu(rxd->mpdu_start.info0),
+		     RX_MPDU_START_INFO0_ENCRYPT_TYPE);
+
+	hdr_len = ieee80211_hdrlen(hdr->frame_control);
+	crypto_len = ath10k_htt_rx_crypto_param_len(ar, enctype);
+
+	subframe_hdr = (u8 *)hdr + round_up(hdr_len, bytes_aligned) +
+		       crypto_len;
+
+	/* Validate if the amsdu has a proper first subframe.
+	 * There are chances a single msdu can be received as amsdu when
+	 * the unauthenticated amsdu flag of a QoS header
+	 * gets flipped in non-SPP AMSDU's, in such cases the first
+	 * subframe has llc/snap header in place of a valid da.
+	 * return false if the da matches rfc1042 pattern
+	 */
+	if (ether_addr_equal(subframe_hdr, rfc1042_header))
+		return false;
+
+	return true;
+}
+
 static bool ath10k_htt_rx_amsdu_allowed(struct ath10k *ar,
 					struct sk_buff_head *amsdu,
 					struct ieee80211_rx_status *rx_status)
 {
-	/* FIXME: It might be a good idea to do some fuzzy-testing to drop
-	 * invalid/dangerous frames.
-	 */
-
 	if (!rx_status->freq) {
 		ath10k_dbg(ar, ATH10K_DBG_HTT, "no channel configured; ignoring frame(s)!\n");
 		return false;
@@ -2126,6 +2174,11 @@ static bool ath10k_htt_rx_amsdu_allowed(struct ath10k *ar,
 		return false;
 	}
 
+	if (!ath10k_htt_rx_validate_amsdu(ar, amsdu)) {
+		ath10k_dbg(ar, ATH10K_DBG_HTT, "invalid amsdu received\n");
+		return false;
+	}
+
 	return true;
 }
 
-- 
2.30.2

[PATCH 17/18] ath11k: Clear the fragment cache during key install

[Johannes Berg]

From: Sriram R <srirrama@codeaurora.org>

Currently the fragment cache setup during peer assoc is
cleared only during peer delete. In case a key reinstallation
happens with the same peer, the same fragment cache with old
fragments added before key installation could be clubbed
with fragments received after. This might be exploited
to mix fragments of different data resulting in a proper
unintended reassembled packet to be passed up the stack.

Hence flush the fragment cache on every key installation to prevent
potential attacks (CVE-2020-24587).

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.4.0.1-01734-QCAHKSWPL_SILICONZ-1 v2

Cc: stable@vger.kernel.org
Signed-off-by: Sriram R <srirrama@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 drivers/net/wireless/ath/ath11k/dp_rx.c | 18 ++++++++++++++++++
 drivers/net/wireless/ath/ath11k/dp_rx.h |  1 +
 drivers/net/wireless/ath/ath11k/mac.c   |  6 ++++++
 3 files changed, 25 insertions(+)

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index 1d9aa1bb6b6e..3382f8bfcb48 100644
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -852,6 +852,24 @@ static void ath11k_dp_rx_frags_cleanup(struct dp_rx_tid *rx_tid, bool rel_link_d
 	__skb_queue_purge(&rx_tid->rx_frags);
 }
 
+void ath11k_peer_frags_flush(struct ath11k *ar, struct ath11k_peer *peer)
+{
+	struct dp_rx_tid *rx_tid;
+	int i;
+
+	lockdep_assert_held(&ar->ab->base_lock);
+
+	for (i = 0; i <= IEEE80211_NUM_TIDS; i++) {
+		rx_tid = &peer->rx_tid[i];
+
+		spin_unlock_bh(&ar->ab->base_lock);
+		del_timer_sync(&rx_tid->frag_timer);
+		spin_lock_bh(&ar->ab->base_lock);
+
+		ath11k_dp_rx_frags_cleanup(rx_tid, true);
+	}
+}
+
 void ath11k_peer_rx_tid_cleanup(struct ath11k *ar, struct ath11k_peer *peer)
 {
 	struct dp_rx_tid *rx_tid;
diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.h b/drivers/net/wireless/ath/ath11k/dp_rx.h
index bf399312b5ff..623da3bf9dc8 100644
--- a/drivers/net/wireless/ath/ath11k/dp_rx.h
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.h
@@ -49,6 +49,7 @@ int ath11k_dp_peer_rx_pn_replay_config(struct ath11k_vif *arvif,
 				       const u8 *peer_addr,
 				       enum set_key_cmd key_cmd,
 				       struct ieee80211_key_conf *key);
+void ath11k_peer_frags_flush(struct ath11k *ar, struct ath11k_peer *peer);
 void ath11k_peer_rx_tid_cleanup(struct ath11k *ar, struct ath11k_peer *peer);
 void ath11k_peer_rx_tid_delete(struct ath11k *ar,
 			       struct ath11k_peer *peer, u8 tid);
diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index 4df425dd31a2..9d0ff150ec30 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -2779,6 +2779,12 @@ static int ath11k_mac_op_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 	 */
 	spin_lock_bh(&ab->base_lock);
 	peer = ath11k_peer_find(ab, arvif->vdev_id, peer_addr);
+
+	/* flush the fragments cache during key (re)install to
+	 * ensure all frags in the new frag list belong to the same key.
+	 */
+	if (peer && cmd == SET_KEY)
+		ath11k_peer_frags_flush(ar, peer);
 	spin_unlock_bh(&ab->base_lock);
 
 	if (!peer) {
-- 
2.30.2

[PATCH 18/18] ath11k: Drop multicast fragments

[Johannes Berg]

From: Sriram R <srirrama@codeaurora.org>

Fragmentation is used only with unicast frames. Drop multicast fragments
to avoid any undesired behavior.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.4.0.1-01734-QCAHKSWPL_SILICONZ-1 v2

Cc: stable@vger.kernel.org
Signed-off-by: Sriram R <srirrama@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
 drivers/net/wireless/ath/ath11k/dp_rx.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/net/wireless/ath/ath11k/dp_rx.c b/drivers/net/wireless/ath/ath11k/dp_rx.c
index 3382f8bfcb48..603d2f93ac18 100644
--- a/drivers/net/wireless/ath/ath11k/dp_rx.c
+++ b/drivers/net/wireless/ath/ath11k/dp_rx.c
@@ -260,6 +260,16 @@ static void ath11k_dp_rxdesc_set_msdu_len(struct ath11k_base *ab,
 	ab->hw_params.hw_ops->rx_desc_set_msdu_len(desc, len);
 }
 
+static bool ath11k_dp_rx_h_attn_is_mcbc(struct ath11k_base *ab,
+					struct hal_rx_desc *desc)
+{
+	struct rx_attention *attn = ath11k_dp_rx_get_attention(ab, desc);
+
+	return ath11k_dp_rx_h_msdu_end_first_msdu(ab, desc) &&
+		(!!FIELD_GET(RX_ATTENTION_INFO1_MCAST_BCAST,
+		 __le32_to_cpu(attn->info1)));
+}
+
 static void ath11k_dp_service_mon_ring(struct timer_list *t)
 {
 	struct ath11k_base *ab = from_timer(ab, t, mon_reap_timer);
@@ -3468,6 +3478,7 @@ static int ath11k_dp_rx_frag_h_mpdu(struct ath11k *ar,
 	u8 tid;
 	int ret = 0;
 	bool more_frags;
+	bool is_mcbc;
 
 	rx_desc = (struct hal_rx_desc *)msdu->data;
 	peer_id = ath11k_dp_rx_h_mpdu_start_peer_id(ar->ab, rx_desc);
@@ -3475,6 +3486,11 @@ static int ath11k_dp_rx_frag_h_mpdu(struct ath11k *ar,
 	seqno = ath11k_dp_rx_h_mpdu_start_seq_no(ar->ab, rx_desc);
 	frag_no = ath11k_dp_rx_h_mpdu_start_frag_no(ar->ab, msdu);
 	more_frags = ath11k_dp_rx_h_mpdu_start_more_frags(ar->ab, msdu);
+	is_mcbc = ath11k_dp_rx_h_attn_is_mcbc(ar->ab, rx_desc);
+
+	/* Multicast/Broadcast fragments are not expected */
+	if (is_mcbc)
+		return -EINVAL;
 
 	if (!ath11k_dp_rx_h_mpdu_start_seq_ctrl_valid(ar->ab, rx_desc) ||
 	    !ath11k_dp_rx_h_mpdu_start_fc_valid(ar->ab, rx_desc) ||
-- 
2.30.2