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025bd93f36
From the patch series description: Several security issues in the 802.11 implementations were found by Mathy Vanhoef (New York University Abu Dhabi), who has published all the details at https://papers.mathyvanhoef.com/usenix2021.pdf Specifically, the following CVEs were assigned: * CVE-2020-24586 - Fragmentation cache not cleared on reconnection * CVE-2020-24587 - Reassembling fragments encrypted under different keys * CVE-2020-24588 - Accepting non-SPP A-MSDU frames, which leads to payload being parsed as an L2 frame under an A-MSDU bit toggling attack * CVE-2020-26139 - Forwarding EAPOL from unauthenticated sender * CVE-2020-26140 - Accepting plaintext data frames in protected networks * CVE-2020-26141 - Not verifying TKIP MIC of fragmented frames * CVE-2020-26142 - Processing fragmented frames as full frames * CVE-2020-26143 - Accepting fragmented plaintext frames in protected networks * CVE-2020-26144 - Always accepting unencrypted A-MSDU frames that start with RFC1042 header with EAPOL ethertype * CVE-2020-26145 - Accepting plaintext broadcast fragments as full frames * CVE-2020-26146 - Reassembling encrypted fragments with non-consecutive packet numbers * CVE-2020-26147 - Reassembling mixed encrypted/plaintext fragments In general, the scope of these attacks is that they may allow an attacker to * inject L2 frames that they can more or less control (depending on the vulnerability and attack method) into an otherwise protected network; * exfiltrate (some) network data under certain conditions, this is specific to the fragmentation issues. A subset of these issues is known to apply to the Linux IEEE 802.11 implementation (mac80211). Where it is affected, the attached patches fix the issues, even if not all of them reference the exact CVE IDs. In addition, driver and/or firmware updates may be necessary, as well as potentially more fixes to mac80211, depending on how drivers are using it. Specifically, for Intel devices, firmware needs to be updated to the most recently released versions (which was done without any reference to the security issues) to address some of the vulnerabilities. To have a single set of patches, I'm also including patches for the ath10k and ath11k drivers here. We currently don't have information about how other drivers are, if at all, affected. Signed-off-by: Felix Fietkau <nbd@nbd.name>
55 lines
1.6 KiB
Diff
55 lines
1.6 KiB
Diff
From: Johannes Berg <johannes.berg@intel.com>
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Date: Tue, 11 May 2021 20:02:46 +0200
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Subject: [PATCH] mac80211: drop A-MSDUs on old ciphers
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With old ciphers (WEP and TKIP) we shouldn't be using A-MSDUs
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since A-MSDUs are only supported if we know that they are, and
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the only practical way for that is HT support which doesn't
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support old ciphers.
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However, we would normally accept them anyway. Since we check
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the MMIC before deaggregating A-MSDUs, and the A-MSDU bit in
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the QoS header is not protected in TKIP (or WEP), this enables
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attacks similar to CVE-2020-24588. To prevent that, drop A-MSDUs
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completely with old ciphers.
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Cc: stable@vger.kernel.org
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Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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---
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--- a/net/mac80211/rx.c
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+++ b/net/mac80211/rx.c
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@@ -6,7 +6,7 @@
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* Copyright 2007-2010 Johannes Berg <johannes@sipsolutions.net>
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* Copyright 2013-2014 Intel Mobile Communications GmbH
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* Copyright(c) 2015 - 2017 Intel Deutschland GmbH
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- * Copyright (C) 2018-2020 Intel Corporation
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+ * Copyright (C) 2018-2021 Intel Corporation
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*/
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#include <linux/jiffies.h>
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@@ -2753,6 +2753,23 @@ ieee80211_rx_h_amsdu(struct ieee80211_rx
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if (is_multicast_ether_addr(hdr->addr1))
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return RX_DROP_UNUSABLE;
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+ if (rx->key) {
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+ /*
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+ * We should not receive A-MSDUs on pre-HT connections,
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+ * and HT connections cannot use old ciphers. Thus drop
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+ * them, as in those cases we couldn't even have SPP
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+ * A-MSDUs or such.
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+ */
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+ switch (rx->key->conf.cipher) {
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+ case WLAN_CIPHER_SUITE_WEP40:
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+ case WLAN_CIPHER_SUITE_WEP104:
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+ case WLAN_CIPHER_SUITE_TKIP:
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+ return RX_DROP_UNUSABLE;
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+ default:
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+ break;
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+ }
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+ }
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+
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return __ieee80211_rx_h_amsdu(rx, 0);
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}
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