git: 8b2ba742cc2c - stable/13 - net80211: prevent plaintext injection by A-MSDU RFC1042/EAPOL frames
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Date: Fri, 19 Nov 2021 00:02:32 UTC
The branch stable/13 has been updated by bz:
URL: https://cgit.FreeBSD.org/src/commit/?id=8b2ba742cc2c732bc4bc1d43f8256adce06657d0
commit 8b2ba742cc2c732bc4bc1d43f8256adce06657d0
Author: Mathy Vanhoef <Mathy.Vanhoef@kuleuven.be>
AuthorDate: 2021-06-06 22:10:56 +0000
Commit: Bjoern A. Zeeb <bz@FreeBSD.org>
CommitDate: 2021-11-19 00:01:25 +0000
net80211: prevent plaintext injection by A-MSDU RFC1042/EAPOL frames
No longer accept plaintext A-MSDU frames that start with an RFC1042
header with EtherType EAPOL. This is done by only accepting EAPOL
packets that are included in non-aggregated 802.11 frames.
Note that before this patch, FreeBSD also only accepted EAPOL frames
that are sent in a non-aggregated 802.11 frame due to bugs in
processing EAPOL packets inside A-MSDUs. In other words,
compatibility with legitimate devices remains the same.
This relates to section 6.5 in the 2021 Usenix "FragAttacks" (Fragment
and Forge: Breaking Wi-Fi Through Frame Aggregation and Fragmentation)
paper.
Submitted by: Mathy Vanhoef (Mathy.Vanhoef kuleuven.be)
Security: CVE-2020-26144
PR: 256120
(cherry picked from commit ffc19cf52da5546973965f78cf32aa0f2c9657f8)
---
sys/net80211/ieee80211_adhoc.c | 18 ++++++++++++------
sys/net80211/ieee80211_hostap.c | 18 ++++++++++++------
sys/net80211/ieee80211_sta.c | 18 ++++++++++++------
sys/net80211/ieee80211_wds.c | 18 ++++++++++++------
4 files changed, 48 insertions(+), 24 deletions(-)
diff --git a/sys/net80211/ieee80211_adhoc.c b/sys/net80211/ieee80211_adhoc.c
index e2164bbb46a1..150515222268 100644
--- a/sys/net80211/ieee80211_adhoc.c
+++ b/sys/net80211/ieee80211_adhoc.c
@@ -571,7 +571,10 @@ adhoc_input(struct ieee80211_node *ni, struct mbuf *m,
IEEE80211_NODE_STAT(ni, rx_decap);
goto err;
}
- eh = mtod(m, struct ether_header *);
+ if (!(qos & IEEE80211_QOS_AMSDU))
+ eh = mtod(m, struct ether_header *);
+ else
+ eh = NULL;
if (!ieee80211_node_is_authorized(ni)) {
/*
* Deny any non-PAE frames received prior to
@@ -581,11 +584,13 @@ adhoc_input(struct ieee80211_node *ni, struct mbuf *m,
* the port is not marked authorized by the
* authenticator until the handshake has completed.
*/
- if (eh->ether_type != htons(ETHERTYPE_PAE)) {
+ if (eh == NULL ||
+ eh->ether_type != htons(ETHERTYPE_PAE)) {
IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
- eh->ether_shost, "data",
- "unauthorized port: ether type 0x%x len %u",
- eh->ether_type, m->m_pkthdr.len);
+ ni->ni_macaddr, "data", "unauthorized or "
+ "unknown port: ether type 0x%x len %u",
+ eh == NULL ? -1 : eh->ether_type,
+ m->m_pkthdr.len);
vap->iv_stats.is_rx_unauth++;
IEEE80211_NODE_STAT(ni, rx_unauth);
goto err;
@@ -598,7 +603,8 @@ adhoc_input(struct ieee80211_node *ni, struct mbuf *m,
if ((vap->iv_flags & IEEE80211_F_DROPUNENC) &&
((has_decrypted == 0) && (m->m_flags & M_WEP) == 0) &&
(is_hw_decrypted == 0) &&
- eh->ether_type != htons(ETHERTYPE_PAE)) {
+ (eh == NULL ||
+ eh->ether_type != htons(ETHERTYPE_PAE))) {
/*
* Drop unencrypted frames.
*/
diff --git a/sys/net80211/ieee80211_hostap.c b/sys/net80211/ieee80211_hostap.c
index 75fa1c0f7b31..4fa9c6a72145 100644
--- a/sys/net80211/ieee80211_hostap.c
+++ b/sys/net80211/ieee80211_hostap.c
@@ -757,7 +757,10 @@ hostap_input(struct ieee80211_node *ni, struct mbuf *m,
IEEE80211_NODE_STAT(ni, rx_decap);
goto err;
}
- eh = mtod(m, struct ether_header *);
+ if (!(qos & IEEE80211_QOS_AMSDU))
+ eh = mtod(m, struct ether_header *);
+ else
+ eh = NULL;
if (!ieee80211_node_is_authorized(ni)) {
/*
* Deny any non-PAE frames received prior to
@@ -767,11 +770,13 @@ hostap_input(struct ieee80211_node *ni, struct mbuf *m,
* the port is not marked authorized by the
* authenticator until the handshake has completed.
*/
- if (eh->ether_type != htons(ETHERTYPE_PAE)) {
+ if (eh == NULL ||
+ eh->ether_type != htons(ETHERTYPE_PAE)) {
IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
- eh->ether_shost, "data",
- "unauthorized port: ether type 0x%x len %u",
- eh->ether_type, m->m_pkthdr.len);
+ ni->ni_macaddr, "data", "unauthorized or "
+ "unknown port: ether type 0x%x len %u",
+ eh == NULL ? -1 : eh->ether_type,
+ m->m_pkthdr.len);
vap->iv_stats.is_rx_unauth++;
IEEE80211_NODE_STAT(ni, rx_unauth);
goto err;
@@ -784,7 +789,8 @@ hostap_input(struct ieee80211_node *ni, struct mbuf *m,
if ((vap->iv_flags & IEEE80211_F_DROPUNENC) &&
((has_decrypted == 0) && (m->m_flags & M_WEP) == 0) &&
(is_hw_decrypted == 0) &&
- eh->ether_type != htons(ETHERTYPE_PAE)) {
+ (eh == NULL ||
+ eh->ether_type != htons(ETHERTYPE_PAE))) {
/*
* Drop unencrypted frames.
*/
diff --git a/sys/net80211/ieee80211_sta.c b/sys/net80211/ieee80211_sta.c
index 60a5ea100556..cd62266ab942 100644
--- a/sys/net80211/ieee80211_sta.c
+++ b/sys/net80211/ieee80211_sta.c
@@ -840,7 +840,10 @@ sta_input(struct ieee80211_node *ni, struct mbuf *m,
IEEE80211_NODE_STAT(ni, rx_decap);
goto err;
}
- eh = mtod(m, struct ether_header *);
+ if (!(qos & IEEE80211_QOS_AMSDU))
+ eh = mtod(m, struct ether_header *);
+ else
+ eh = NULL;
if (!ieee80211_node_is_authorized(ni)) {
/*
* Deny any non-PAE frames received prior to
@@ -850,11 +853,13 @@ sta_input(struct ieee80211_node *ni, struct mbuf *m,
* the port is not marked authorized by the
* authenticator until the handshake has completed.
*/
- if (eh->ether_type != htons(ETHERTYPE_PAE)) {
+ if (eh == NULL ||
+ eh->ether_type != htons(ETHERTYPE_PAE)) {
IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
- eh->ether_shost, "data",
- "unauthorized port: ether type 0x%x len %u",
- eh->ether_type, m->m_pkthdr.len);
+ ni->ni_macaddr, "data", "unauthorized or "
+ "unknown port: ether type 0x%x len %u",
+ eh == NULL ? -1 : eh->ether_type,
+ m->m_pkthdr.len);
vap->iv_stats.is_rx_unauth++;
IEEE80211_NODE_STAT(ni, rx_unauth);
goto err;
@@ -867,7 +872,8 @@ sta_input(struct ieee80211_node *ni, struct mbuf *m,
if ((vap->iv_flags & IEEE80211_F_DROPUNENC) &&
((has_decrypted == 0) && (m->m_flags & M_WEP) == 0) &&
(is_hw_decrypted == 0) &&
- eh->ether_type != htons(ETHERTYPE_PAE)) {
+ (eh == NULL ||
+ eh->ether_type != htons(ETHERTYPE_PAE))) {
/*
* Drop unencrypted frames.
*/
diff --git a/sys/net80211/ieee80211_wds.c b/sys/net80211/ieee80211_wds.c
index f88871ca4ae6..b73988b10d5e 100644
--- a/sys/net80211/ieee80211_wds.c
+++ b/sys/net80211/ieee80211_wds.c
@@ -634,7 +634,10 @@ wds_input(struct ieee80211_node *ni, struct mbuf *m,
IEEE80211_NODE_STAT(ni, rx_decap);
goto err;
}
- eh = mtod(m, struct ether_header *);
+ if (!(qos & IEEE80211_QOS_AMSDU))
+ eh = mtod(m, struct ether_header *);
+ else
+ eh = NULL;
if (!ieee80211_node_is_authorized(ni)) {
/*
* Deny any non-PAE frames received prior to
@@ -644,11 +647,13 @@ wds_input(struct ieee80211_node *ni, struct mbuf *m,
* the port is not marked authorized by the
* authenticator until the handshake has completed.
*/
- if (eh->ether_type != htons(ETHERTYPE_PAE)) {
+ if (eh == NULL ||
+ eh->ether_type != htons(ETHERTYPE_PAE)) {
IEEE80211_DISCARD_MAC(vap, IEEE80211_MSG_INPUT,
- eh->ether_shost, "data",
- "unauthorized port: ether type 0x%x len %u",
- eh->ether_type, m->m_pkthdr.len);
+ ni->ni_macaddr, "data", "unauthorized or "
+ "unknown port: ether type 0x%x len %u",
+ eh == NULL ? -1 : eh->ether_type,
+ m->m_pkthdr.len);
vap->iv_stats.is_rx_unauth++;
IEEE80211_NODE_STAT(ni, rx_unauth);
goto err;
@@ -661,7 +666,8 @@ wds_input(struct ieee80211_node *ni, struct mbuf *m,
if ((vap->iv_flags & IEEE80211_F_DROPUNENC) &&
((has_decrypted == 0) && (m->m_flags & M_WEP) == 0) &&
(is_hw_decrypted == 0) &&
- eh->ether_type != htons(ETHERTYPE_PAE)) {
+ (eh == NULL ||
+ eh->ether_type != htons(ETHERTYPE_PAE))) {
/*
* Drop unencrypted frames.
*/