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From: Johannes Berg <johannes@sipsolutions.net>
To: linux-wireless@vger.kernel.org
Cc: Johannes Berg <johannes.berg@intel.com>, stable@vger.kernel.org
Subject: [PATCH 07/18] mac80211: check defrag PN against current frame
Date: Tue, 11 May 2021 20:02:48 +0200	[thread overview]
Message-ID: <20210511200110.bfbc340ff071.Id0b690e581da7d03d76df90bb0e3fd55930bc8a0@changeid> (raw)
In-Reply-To: <20210511180259.159598-1-johannes@sipsolutions.net>

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


  parent reply	other threads:[~2021-05-11 18:03 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-11 18:02 [PATCH 00/18] mac80211/driver security fixes Johannes Berg
2021-05-11 18:02 ` [PATCH 01/18] mac80211: assure all fragments are encrypted Johannes Berg
2021-05-11 18:02 ` [PATCH 02/18] mac80211: prevent mixed key and fragment cache attacks Johannes Berg
2021-05-11 18:02 ` [PATCH 03/18] mac80211: properly handle A-MSDUs that start with an RFC 1042 header Johannes Berg
2021-05-11 18:02 ` [PATCH 04/18] cfg80211: mitigate A-MSDU aggregation attacks Johannes Berg
2021-05-11 18:02 ` [PATCH 05/18] mac80211: drop A-MSDUs on old ciphers Johannes Berg
2021-05-11 18:02 ` [PATCH 06/18] mac80211: add fragment cache to sta_info Johannes Berg
2021-05-11 18:02 ` Johannes Berg [this message]
2021-05-11 18:02 ` [PATCH 08/18] mac80211: prevent attacks on TKIP/WEP as well Johannes Berg
2021-05-11 18:02 ` [PATCH 09/18] mac80211: do not accept/forward invalid EAPOL frames Johannes Berg
2021-05-11 18:02 ` [PATCH 10/18] mac80211: extend protection against mixed key and fragment cache attacks Johannes Berg
2021-05-11 18:02 ` [PATCH 11/18] ath10k: add CCMP PN replay protection for fragmented frames for PCIe Johannes Berg
2021-05-14 22:23   ` Abhishek Kumar
2021-05-11 18:02 ` [PATCH 12/18] ath10k: drop fragments with multicast DA " Johannes Berg
2021-05-11 18:02 ` [PATCH 13/18] ath10k: drop fragments with multicast DA for SDIO Johannes Berg
2021-05-11 18:02 ` [PATCH 14/18] ath10k: drop MPDU which has discard flag set by firmware " Johannes Berg
2021-05-12 18:35   ` Brian Norris
2021-05-13 17:18     ` Jeff Johnson
2021-05-11 18:02 ` [PATCH 15/18] ath10k: Fix TKIP Michael MIC verification for PCIe Johannes Berg
2021-05-11 18:02 ` [PATCH 16/18] ath10k: Validate first subframe of A-MSDU before processing the list Johannes Berg
2021-05-11 18:02 ` [PATCH 17/18] ath11k: Clear the fragment cache during key install Johannes Berg
2021-05-11 18:02 ` [PATCH 18/18] ath11k: Drop multicast fragments Johannes Berg
2021-05-17 18:54 ` [PATCH 00/18] mac80211/driver security fixes Ben Greear

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