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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>
69 lines
2.6 KiB
Diff
69 lines
2.6 KiB
Diff
From: Wen Gong <wgong@codeaurora.org>
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Date: Tue, 11 May 2021 20:02:51 +0200
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Subject: [PATCH] mac80211: extend protection against mixed key and
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fragment cache attacks
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For some chips/drivers, e.g., QCA6174 with ath10k, the decryption is
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done by the hardware, and the Protected bit in the Frame Control field
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is cleared in the lower level driver before the frame is passed to
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mac80211. In such cases, the condition for ieee80211_has_protected() is
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not met in ieee80211_rx_h_defragment() of mac80211 and the new security
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validation steps are not executed.
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Extend mac80211 to cover the case where the Protected bit has been
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cleared, but the frame is indicated as having been decrypted by the
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hardware. This extends protection against mixed key and fragment cache
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attack for additional drivers/chips. This fixes CVE-2020-24586 and
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CVE-2020-24587 for such cases.
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Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00110-QCARMSWP-1
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Cc: stable@vger.kernel.org
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Signed-off-by: Wen Gong <wgong@codeaurora.org>
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Signed-off-by: Jouni Malinen <jouni@codeaurora.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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@@ -2239,6 +2239,7 @@ ieee80211_rx_h_defragment(struct ieee802
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unsigned int frag, seq;
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struct ieee80211_fragment_entry *entry;
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struct sk_buff *skb;
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+ struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(rx->skb);
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hdr = (struct ieee80211_hdr *)rx->skb->data;
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fc = hdr->frame_control;
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@@ -2297,7 +2298,9 @@ ieee80211_rx_h_defragment(struct ieee802
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sizeof(rx->key->u.gcmp.rx_pn[queue]));
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BUILD_BUG_ON(IEEE80211_CCMP_PN_LEN !=
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IEEE80211_GCMP_PN_LEN);
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- } else if (rx->key && ieee80211_has_protected(fc)) {
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+ } else if (rx->key &&
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+ (ieee80211_has_protected(fc) ||
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+ (status->flag & RX_FLAG_DECRYPTED))) {
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entry->is_protected = true;
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entry->key_color = rx->key->color;
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}
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@@ -2342,13 +2345,19 @@ ieee80211_rx_h_defragment(struct ieee802
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return RX_DROP_UNUSABLE;
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memcpy(entry->last_pn, pn, IEEE80211_CCMP_PN_LEN);
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} else if (entry->is_protected &&
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- (!rx->key || !ieee80211_has_protected(fc) ||
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+ (!rx->key ||
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+ (!ieee80211_has_protected(fc) &&
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+ !(status->flag & RX_FLAG_DECRYPTED)) ||
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rx->key->color != entry->key_color)) {
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/* Drop this as a mixed key or fragment cache attack, even
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* if for TKIP Michael MIC should protect us, and WEP is a
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* lost cause anyway.
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*/
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return RX_DROP_UNUSABLE;
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+ } else if (entry->is_protected && rx->key &&
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+ entry->key_color != rx->key->color &&
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+ (status->flag & RX_FLAG_DECRYPTED)) {
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+ return RX_DROP_UNUSABLE;
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}
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skb_pull(rx->skb, ieee80211_hdrlen(fc));
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