git: 267e8f64e4d3 - main - net80211: validate control frame TA/RA before further processing
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Date: Fri, 25 Apr 2025 05:38:42 UTC
The branch main has been updated by adrian: URL: https://cgit.FreeBSD.org/src/commit/?id=267e8f64e4d366ce6901cea5e360af528acb0887 commit 267e8f64e4d366ce6901cea5e360af528acb0887 Author: Adrian Chadd <adrian@FreeBSD.org> AuthorDate: 2025-03-30 00:03:17 +0000 Commit: Adrian Chadd <adrian@FreeBSD.org> CommitDate: 2025-04-25 05:35:49 +0000 net80211: validate control frame TA/RA before further processing An earlier commit relaxed the TA/RA rules around control frames to fix other issues, however it now results in control frames not specifically from a known node / to us to be handled in the control path. Specifically, rtwn(4) RTL8812/RTL8821 NICs are currently passing BARs from the AP TA to any destination to us; which is tripping up BAW tracking and causing traffic hangs. So do the check before vap->iv_recv_ctl() is called in each input path. Note that mesh doesn't seem to pass the control frames up; however I haven't tested/validated mesh in a long while and I know it's currently broken. Differential Revision: https://reviews.freebsd.org/D49575 --- sys/net80211/ieee80211.c | 54 +++++++++++++++++++++++++++++++++++++++++ sys/net80211/ieee80211_adhoc.c | 3 ++- sys/net80211/ieee80211_hostap.c | 3 ++- sys/net80211/ieee80211_sta.c | 4 ++- sys/net80211/ieee80211_var.h | 3 +++ 5 files changed, 64 insertions(+), 3 deletions(-) diff --git a/sys/net80211/ieee80211.c b/sys/net80211/ieee80211.c index 9d036f298ed3..dbc7023c7fee 100644 --- a/sys/net80211/ieee80211.c +++ b/sys/net80211/ieee80211.c @@ -2732,3 +2732,57 @@ ieee80211_is_key_unicast(const struct ieee80211vap *vap, */ return (!ieee80211_is_key_global(vap, key)); } + +/** + * Determine whether the given control frame is from a known node + * and destined to us. + * + * In some instances a control frame won't have a TA (eg ACKs), so + * we should only verify the RA for those. + * + * @param ni ieee80211_node representing the sender, or BSS node + * @param m0 mbuf representing the 802.11 frame. + * @returns false if the frame is not a CTL frame (with a warning logged); + * true if the frame is from a known sender / valid recipient, + * false otherwise. + */ +bool +ieee80211_is_ctl_frame_for_vap(struct ieee80211_node *ni, const struct mbuf *m0) +{ + const struct ieee80211vap *vap = ni->ni_vap; + const struct ieee80211_frame *wh; + uint8_t subtype; + + wh = mtod(m0, const struct ieee80211_frame *); + subtype = wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK; + + /* Verify it's a ctl frame. */ + KASSERT(IEEE80211_IS_CTL(wh), ("%s: not a CTL frame (fc[0]=0x%04x)", + __func__, wh->i_fc[0])); + if (!IEEE80211_IS_CTL(wh)) { + if_printf(vap->iv_ifp, + "%s: not a control frame (fc[0]=0x%04x)\n", + __func__, wh->i_fc[0]); + return (false); + } + + /* Verify the TA if present. */ + switch (subtype) { + case IEEE80211_FC0_SUBTYPE_CTS: + case IEEE80211_FC0_SUBTYPE_ACK: + /* No TA. */ + break; + default: + /* + * Verify TA matches ni->ni_macaddr; for unknown + * sources it will be the BSS node and ni->ni_macaddr + * will the BSS MAC. + */ + if (!IEEE80211_ADDR_EQ(wh->i_addr2, ni->ni_macaddr)) + return (false); + break; + } + + /* Verify the RA */ + return (IEEE80211_ADDR_EQ(wh->i_addr1, vap->iv_myaddr)); +} diff --git a/sys/net80211/ieee80211_adhoc.c b/sys/net80211/ieee80211_adhoc.c index 77e5a2d99904..210c9fc75bd9 100644 --- a/sys/net80211/ieee80211_adhoc.c +++ b/sys/net80211/ieee80211_adhoc.c @@ -661,7 +661,8 @@ adhoc_input(struct ieee80211_node *ni, struct mbuf *m, case IEEE80211_FC0_TYPE_CTL: vap->iv_stats.is_rx_ctl++; IEEE80211_NODE_STAT(ni, rx_ctrl); - vap->iv_recv_ctl(ni, m, subtype); + if (ieee80211_is_ctl_frame_for_vap(ni, m)) + vap->iv_recv_ctl(ni, m, subtype); goto out; default: diff --git a/sys/net80211/ieee80211_hostap.c b/sys/net80211/ieee80211_hostap.c index c9e2c4896f15..1573d83f4cb4 100644 --- a/sys/net80211/ieee80211_hostap.c +++ b/sys/net80211/ieee80211_hostap.c @@ -889,7 +889,8 @@ hostap_input(struct ieee80211_node *ni, struct mbuf *m, case IEEE80211_FC0_TYPE_CTL: vap->iv_stats.is_rx_ctl++; IEEE80211_NODE_STAT(ni, rx_ctrl); - vap->iv_recv_ctl(ni, m, subtype); + if (ieee80211_is_ctl_frame_for_vap(ni, m)) + vap->iv_recv_ctl(ni, m, subtype); goto out; default: IEEE80211_DISCARD(vap, IEEE80211_MSG_ANY, diff --git a/sys/net80211/ieee80211_sta.c b/sys/net80211/ieee80211_sta.c index 48d56d0ad217..887eb81dd3c4 100644 --- a/sys/net80211/ieee80211_sta.c +++ b/sys/net80211/ieee80211_sta.c @@ -972,7 +972,8 @@ sta_input(struct ieee80211_node *ni, struct mbuf *m, case IEEE80211_FC0_TYPE_CTL: vap->iv_stats.is_rx_ctl++; IEEE80211_NODE_STAT(ni, rx_ctrl); - vap->iv_recv_ctl(ni, m, subtype); + if (ieee80211_is_ctl_frame_for_vap(ni, m)) + vap->iv_recv_ctl(ni, m, subtype); goto out; default: @@ -2054,6 +2055,7 @@ sta_recv_mgmt(struct ieee80211_node *ni, struct mbuf *m0, int subtype, static void sta_recv_ctl(struct ieee80211_node *ni, struct mbuf *m, int subtype) { + switch (subtype) { case IEEE80211_FC0_SUBTYPE_BAR: ieee80211_recv_bar(ni, m); diff --git a/sys/net80211/ieee80211_var.h b/sys/net80211/ieee80211_var.h index e011d2dd32ed..91beaec6f997 100644 --- a/sys/net80211/ieee80211_var.h +++ b/sys/net80211/ieee80211_var.h @@ -845,6 +845,9 @@ bool ieee80211_is_key_global(const struct ieee80211vap *vap, bool ieee80211_is_key_unicast(const struct ieee80211vap *vap, const struct ieee80211_key *key); +bool ieee80211_is_ctl_frame_for_vap(struct ieee80211_node *, + const struct mbuf *); + void ieee80211_radiotap_attach(struct ieee80211com *, struct ieee80211_radiotap_header *th, int tlen, uint32_t tx_radiotap,