Skip to content

Commit

Permalink
mac80211: backport upstream fixes for FragAttacks
Browse files Browse the repository at this point in the history
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>
  • Loading branch information
nbd168 committed May 12, 2021
1 parent 5a96081 commit 025bd93
Show file tree
Hide file tree
Showing 23 changed files with 1,466 additions and 7 deletions.
Expand Up @@ -37,7 +37,7 @@
void ath10k_thermal_event_temperature(struct ath10k *ar, int temperature);
--- a/local-symbols
+++ b/local-symbols
@@ -142,6 +142,7 @@ ATH10K_SNOC=
@@ -143,6 +143,7 @@ ATH10K_SNOC=
ATH10K_DEBUG=
ATH10K_DEBUGFS=
ATH10K_SPECTRAL=
Expand Down
@@ -0,0 +1,180 @@
From: Wen Gong <wgong@codeaurora.org>
Date: Tue, 11 May 2021 20:02:52 +0200
Subject: [PATCH] ath10k: add CCMP PN replay protection for fragmented
frames for PCIe

PN replay check for not fragmented frames is finished in the firmware,
but this was not done for fragmented frames when ath10k is used with
QCA6174/QCA6377 PCIe. mac80211 has the function
ieee80211_rx_h_defragment() for PN replay check for fragmented frames,
but this does not get checked with QCA6174 due to the
ieee80211_has_protected() condition not matching the cleared Protected
bit case.

Validate the PN of received fragmented frames within ath10k when CCMP is
used and drop the fragment if the PN is not correct (incremented by
exactly one from the previous fragment). This applies only for
QCA6174/QCA6377 PCIe.

Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00110-QCARMSWP-1

Cc: stable@vger.kernel.org
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---

--- a/drivers/net/wireless/ath/ath10k/htt.h
+++ b/drivers/net/wireless/ath/ath10k/htt.h
@@ -846,6 +846,7 @@ enum htt_security_types {

#define ATH10K_HTT_TXRX_PEER_SECURITY_MAX 2
#define ATH10K_TXRX_NUM_EXT_TIDS 19
+#define ATH10K_TXRX_NON_QOS_TID 16

enum htt_security_flags {
#define HTT_SECURITY_TYPE_MASK 0x7F
--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -1746,16 +1746,87 @@ static void ath10k_htt_rx_h_csum_offload
msdu->ip_summed = ath10k_htt_rx_get_csum_state(msdu);
}

+static u64 ath10k_htt_rx_h_get_pn(struct ath10k *ar, struct sk_buff *skb,
+ u16 offset,
+ enum htt_rx_mpdu_encrypt_type enctype)
+{
+ struct ieee80211_hdr *hdr;
+ u64 pn = 0;
+ u8 *ehdr;
+
+ hdr = (struct ieee80211_hdr *)(skb->data + offset);
+ ehdr = skb->data + offset + ieee80211_hdrlen(hdr->frame_control);
+
+ if (enctype == HTT_RX_MPDU_ENCRYPT_AES_CCM_WPA2) {
+ pn = ehdr[0];
+ pn |= (u64)ehdr[1] << 8;
+ pn |= (u64)ehdr[4] << 16;
+ pn |= (u64)ehdr[5] << 24;
+ pn |= (u64)ehdr[6] << 32;
+ pn |= (u64)ehdr[7] << 40;
+ }
+ return pn;
+}
+
+static bool ath10k_htt_rx_h_frag_pn_check(struct ath10k *ar,
+ struct sk_buff *skb,
+ u16 peer_id,
+ u16 offset,
+ enum htt_rx_mpdu_encrypt_type enctype)
+{
+ struct ath10k_peer *peer;
+ union htt_rx_pn_t *last_pn, new_pn = {0};
+ struct ieee80211_hdr *hdr;
+ bool more_frags;
+ u8 tid, frag_number;
+ u32 seq;
+
+ peer = ath10k_peer_find_by_id(ar, peer_id);
+ if (!peer) {
+ ath10k_dbg(ar, ATH10K_DBG_HTT, "invalid peer for frag pn check\n");
+ return false;
+ }
+
+ hdr = (struct ieee80211_hdr *)(skb->data + offset);
+ if (ieee80211_is_data_qos(hdr->frame_control))
+ tid = ieee80211_get_tid(hdr);
+ else
+ tid = ATH10K_TXRX_NON_QOS_TID;
+
+ last_pn = &peer->frag_tids_last_pn[tid];
+ new_pn.pn48 = ath10k_htt_rx_h_get_pn(ar, skb, offset, enctype);
+ more_frags = ieee80211_has_morefrags(hdr->frame_control);
+ frag_number = le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG;
+ seq = (__le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_SEQ) >> 4;
+
+ if (frag_number == 0) {
+ last_pn->pn48 = new_pn.pn48;
+ peer->frag_tids_seq[tid] = seq;
+ } else {
+ if (seq != peer->frag_tids_seq[tid])
+ return false;
+
+ if (new_pn.pn48 != last_pn->pn48 + 1)
+ return false;
+
+ last_pn->pn48 = new_pn.pn48;
+ }
+
+ return true;
+}
+
static void ath10k_htt_rx_h_mpdu(struct ath10k *ar,
struct sk_buff_head *amsdu,
struct ieee80211_rx_status *status,
bool fill_crypt_header,
u8 *rx_hdr,
- enum ath10k_pkt_rx_err *err)
+ enum ath10k_pkt_rx_err *err,
+ u16 peer_id,
+ bool frag)
{
struct sk_buff *first;
struct sk_buff *last;
- struct sk_buff *msdu;
+ struct sk_buff *msdu, *temp;
struct htt_rx_desc *rxd;
struct ieee80211_hdr *hdr;
enum htt_rx_mpdu_encrypt_type enctype;
@@ -1768,6 +1839,7 @@ static void ath10k_htt_rx_h_mpdu(struct
bool is_decrypted;
bool is_mgmt;
u32 attention;
+ bool frag_pn_check = true;

if (skb_queue_empty(amsdu))
return;
@@ -1866,6 +1938,24 @@ static void ath10k_htt_rx_h_mpdu(struct
}

skb_queue_walk(amsdu, msdu) {
+ if (frag && !fill_crypt_header && is_decrypted &&
+ enctype == HTT_RX_MPDU_ENCRYPT_AES_CCM_WPA2)
+ frag_pn_check = ath10k_htt_rx_h_frag_pn_check(ar,
+ msdu,
+ peer_id,
+ 0,
+ enctype);
+
+ if (!frag_pn_check) {
+ /* Discard the fragment with invalid PN */
+ temp = msdu->prev;
+ __skb_unlink(msdu, amsdu);
+ dev_kfree_skb_any(msdu);
+ msdu = temp;
+ frag_pn_check = true;
+ continue;
+ }
+
ath10k_htt_rx_h_csum_offload(msdu);
ath10k_htt_rx_h_undecap(ar, msdu, status, first_hdr, enctype,
is_decrypted);
@@ -2071,7 +2161,8 @@ static int ath10k_htt_rx_handle_amsdu(st
ath10k_htt_rx_h_unchain(ar, &amsdu, &drop_cnt, &unchain_cnt);

ath10k_htt_rx_h_filter(ar, &amsdu, rx_status, &drop_cnt_filter);
- ath10k_htt_rx_h_mpdu(ar, &amsdu, rx_status, true, first_hdr, &err);
+ ath10k_htt_rx_h_mpdu(ar, &amsdu, rx_status, true, first_hdr, &err, 0,
+ false);
msdus_to_queue = skb_queue_len(&amsdu);
ath10k_htt_rx_h_enqueue(ar, &amsdu, rx_status);

@@ -3027,7 +3118,7 @@ static int ath10k_htt_rx_in_ord_ind(stru
ath10k_htt_rx_h_ppdu(ar, &amsdu, status, vdev_id);
ath10k_htt_rx_h_filter(ar, &amsdu, status, NULL);
ath10k_htt_rx_h_mpdu(ar, &amsdu, status, false, NULL,
- NULL);
+ NULL, peer_id, frag);
ath10k_htt_rx_h_enqueue(ar, &amsdu, status);
break;
case -EAGAIN:
@@ -0,0 +1,66 @@
From: Wen Gong <wgong@codeaurora.org>
Date: Tue, 11 May 2021 20:02:53 +0200
Subject: [PATCH] ath10k: drop fragments with multicast DA for PCIe

Fragmentation is not used with multicast frames. Discard unexpected
fragments with multicast DA. This fixes CVE-2020-26145.

Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00110-QCARMSWP-1

Cc: stable@vger.kernel.org
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---

--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -1768,6 +1768,16 @@ static u64 ath10k_htt_rx_h_get_pn(struct
return pn;
}

+static bool ath10k_htt_rx_h_frag_multicast_check(struct ath10k *ar,
+ struct sk_buff *skb,
+ u16 offset)
+{
+ struct ieee80211_hdr *hdr;
+
+ hdr = (struct ieee80211_hdr *)(skb->data + offset);
+ return !is_multicast_ether_addr(hdr->addr1);
+}
+
static bool ath10k_htt_rx_h_frag_pn_check(struct ath10k *ar,
struct sk_buff *skb,
u16 peer_id,
@@ -1839,7 +1849,7 @@ static void ath10k_htt_rx_h_mpdu(struct
bool is_decrypted;
bool is_mgmt;
u32 attention;
- bool frag_pn_check = true;
+ bool frag_pn_check = true, multicast_check = true;

if (skb_queue_empty(amsdu))
return;
@@ -1946,13 +1956,20 @@ static void ath10k_htt_rx_h_mpdu(struct
0,
enctype);

- if (!frag_pn_check) {
- /* Discard the fragment with invalid PN */
+ if (frag)
+ multicast_check = ath10k_htt_rx_h_frag_multicast_check(ar,
+ msdu,
+ 0);
+
+ if (!frag_pn_check || !multicast_check) {
+ /* Discard the fragment with invalid PN or multicast DA
+ */
temp = msdu->prev;
__skb_unlink(msdu, amsdu);
dev_kfree_skb_any(msdu);
msdu = temp;
frag_pn_check = true;
+ multicast_check = true;
continue;
}

@@ -0,0 +1,40 @@
From: Wen Gong <wgong@codeaurora.org>
Date: Tue, 11 May 2021 20:02:54 +0200
Subject: [PATCH] ath10k: drop fragments with multicast DA for SDIO

Fragmentation is not used with multicast frames. Discard unexpected
fragments with multicast DA. This fixes CVE-2020-26145.

Tested-on: QCA6174 hw3.2 SDIO WLAN.RMH.4.4.1-00049

Cc: stable@vger.kernel.org
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---

--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -2617,6 +2617,13 @@ static bool ath10k_htt_rx_proc_rx_frag_i
rx_desc = (struct htt_hl_rx_desc *)(skb->data + tot_hdr_len);
rx_desc_info = __le32_to_cpu(rx_desc->info);

+ hdr = (struct ieee80211_hdr *)((u8 *)rx_desc + rx_hl->fw_desc.len);
+
+ if (is_multicast_ether_addr(hdr->addr1)) {
+ /* Discard the fragment with multicast DA */
+ goto err;
+ }
+
if (!MS(rx_desc_info, HTT_RX_DESC_HL_INFO_ENCRYPTED)) {
spin_unlock_bh(&ar->data_lock);
return ath10k_htt_rx_proc_rx_ind_hl(htt, &resp->rx_ind_hl, skb,
@@ -2624,8 +2631,6 @@ static bool ath10k_htt_rx_proc_rx_frag_i
HTT_RX_NON_TKIP_MIC);
}

- hdr = (struct ieee80211_hdr *)((u8 *)rx_desc + rx_hl->fw_desc.len);
-
if (ieee80211_has_retry(hdr->frame_control))
goto err;

@@ -0,0 +1,54 @@
From: Wen Gong <wgong@codeaurora.org>
Date: Tue, 11 May 2021 20:02:55 +0200
Subject: [PATCH] ath10k: drop MPDU which has discard flag set by firmware
for SDIO

When the discard flag is set by the firmware for an MPDU, it should be
dropped. This allows a mitigation for CVE-2020-24588 to be implemented
in the firmware.

Tested-on: QCA6174 hw3.2 SDIO WLAN.RMH.4.4.1-00049

Cc: stable@vger.kernel.org
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---

--- a/drivers/net/wireless/ath/ath10k/htt_rx.c
+++ b/drivers/net/wireless/ath/ath10k/htt_rx.c
@@ -2312,6 +2312,11 @@ static bool ath10k_htt_rx_proc_rx_ind_hl
fw_desc = &rx->fw_desc;
rx_desc_len = fw_desc->len;

+ if (fw_desc->u.bits.discard) {
+ ath10k_dbg(ar, ATH10K_DBG_HTT, "htt discard mpdu\n");
+ goto err;
+ }
+
/* I have not yet seen any case where num_mpdu_ranges > 1.
* qcacld does not seem handle that case either, so we introduce the
* same limitiation here as well.
--- a/drivers/net/wireless/ath/ath10k/rx_desc.h
+++ b/drivers/net/wireless/ath/ath10k/rx_desc.h
@@ -1282,7 +1282,19 @@ struct fw_rx_desc_base {
#define FW_RX_DESC_UDP (1 << 6)

struct fw_rx_desc_hl {
- u8 info0;
+ union {
+ struct {
+ u8 discard:1,
+ forward:1,
+ any_err:1,
+ dup_err:1,
+ reserved:1,
+ inspect:1,
+ extension:2;
+ } bits;
+ u8 info0;
+ } u;
+
u8 version;
u8 len;
u8 flags;

0 comments on commit 025bd93

Please sign in to comment.