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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 08/18] mac80211: prevent attacks on TKIP/WEP as well
Date: Tue, 11 May 2021 20:02:49 +0200	[thread overview]
Message-ID: <20210511200110.430e8c202313.Ia37e4e5b6b3eaab1a5ae050e015f6c92859dbe27@changeid> (raw)
In-Reply-To: <20210511180259.159598-1-johannes@sipsolutions.net>

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


  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 ` [PATCH 07/18] mac80211: check defrag PN against current frame Johannes Berg
2021-05-11 18:02 ` Johannes Berg [this message]
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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