The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 7e44a0b597f04e67eee8cdcbe7ee706c6f5de38b Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg(a)intel.com>
Date: Tue, 11 May 2021 20:02:49 +0200
Subject: [PATCH] mac80211: prevent attacks on TKIP/WEP as well
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(a)vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.430e8c202313.Ia37e4e5b6b3eaab1a5ae…
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
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;
};
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 7e44a0b597f04e67eee8cdcbe7ee706c6f5de38b Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg(a)intel.com>
Date: Tue, 11 May 2021 20:02:49 +0200
Subject: [PATCH] mac80211: prevent attacks on TKIP/WEP as well
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(a)vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.430e8c202313.Ia37e4e5b6b3eaab1a5ae…
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
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;
};
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From bf30ca922a0c0176007e074b0acc77ed345e9990 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg(a)intel.com>
Date: Tue, 11 May 2021 20:02:48 +0200
Subject: [PATCH] mac80211: check defrag PN against current frame
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(a)vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.bfbc340ff071.Id0b690e581da7d03d76d…
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
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(a)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 */
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 3a11ce08c45b50d69c891d71760b7c5b92074709 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg(a)intel.com>
Date: Tue, 11 May 2021 20:02:47 +0200
Subject: [PATCH] mac80211: add fragment cache to sta_info
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(a)vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.fc35046b0d52.I1ef101e3784d13e8f660…
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
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(a)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(a)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;
};
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 3a11ce08c45b50d69c891d71760b7c5b92074709 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg(a)intel.com>
Date: Tue, 11 May 2021 20:02:47 +0200
Subject: [PATCH] mac80211: add fragment cache to sta_info
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(a)vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.fc35046b0d52.I1ef101e3784d13e8f660…
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
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(a)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(a)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;
};
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 3a11ce08c45b50d69c891d71760b7c5b92074709 Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg(a)intel.com>
Date: Tue, 11 May 2021 20:02:47 +0200
Subject: [PATCH] mac80211: add fragment cache to sta_info
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(a)vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.fc35046b0d52.I1ef101e3784d13e8f660…
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
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(a)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(a)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;
};
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 270032a2a9c4535799736142e1e7c413ca7b836e Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg(a)intel.com>
Date: Tue, 11 May 2021 20:02:46 +0200
Subject: [PATCH] mac80211: drop A-MSDUs on old ciphers
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(a)vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.076543300172.I548e6e71f1ee9cad4b9a…
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
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(a)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);
}
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 270032a2a9c4535799736142e1e7c413ca7b836e Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg(a)intel.com>
Date: Tue, 11 May 2021 20:02:46 +0200
Subject: [PATCH] mac80211: drop A-MSDUs on old ciphers
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(a)vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.076543300172.I548e6e71f1ee9cad4b9a…
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
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(a)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);
}
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 270032a2a9c4535799736142e1e7c413ca7b836e Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg(a)intel.com>
Date: Tue, 11 May 2021 20:02:46 +0200
Subject: [PATCH] mac80211: drop A-MSDUs on old ciphers
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(a)vger.kernel.org
Link: https://lore.kernel.org/r/20210511200110.076543300172.I548e6e71f1ee9cad4b9a…
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
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(a)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);
}
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 2b8a1fee3488c602aca8bea004a087e60806a5cf Mon Sep 17 00:00:00 2001
From: Mathy Vanhoef <Mathy.Vanhoef(a)kuleuven.be>
Date: Tue, 11 May 2021 20:02:45 +0200
Subject: [PATCH] cfg80211: mitigate A-MSDU aggregation attacks
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(a)vger.kernel.org
Signed-off-by: Mathy Vanhoef <Mathy.Vanhoef(a)kuleuven.be>
Link: https://lore.kernel.org/r/20210511200110.25d93176ddaf.I9e265b597f2cd23eb445…
Signed-off-by: Johannes Berg <johannes.berg(a)intel.com>
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;