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- From 8c07fa9eda13e835f3f968b2e1c9a8be3a851ff9 Mon Sep 17 00:00:00 2001
- From: Jouni Malinen <j@w1.fi>
- Date: Thu, 29 Aug 2019 11:52:04 +0300
- Subject: [PATCH] AP: Silently ignore management frame from unexpected source
- address
- Do not process any received Management frames with unexpected/invalid SA
- so that we do not add any state for unexpected STA addresses or end up
- sending out frames to unexpected destination. This prevents unexpected
- sequences where an unprotected frame might end up causing the AP to send
- out a response to another device and that other device processing the
- unexpected response.
- In particular, this prevents some potential denial of service cases
- where the unexpected response frame from the AP might result in a
- connected station dropping its association.
- Signed-off-by: Jouni Malinen <j@w1.fi>
- ---
- src/ap/drv_callbacks.c | 13 +++++++++++++
- src/ap/ieee802_11.c | 12 ++++++++++++
- 2 files changed, 25 insertions(+)
- diff --git a/src/ap/drv_callbacks.c b/src/ap/drv_callbacks.c
- index 31587685fe3b..34ca379edc3d 100644
- --- a/src/ap/drv_callbacks.c
- +++ b/src/ap/drv_callbacks.c
- @@ -131,6 +131,19 @@ int hostapd_notif_assoc(struct hostapd_data *hapd, const u8 *addr,
- "hostapd_notif_assoc: Skip event with no address");
- return -1;
- }
- +
- + if (is_multicast_ether_addr(addr) ||
- + is_zero_ether_addr(addr) ||
- + os_memcmp(addr, hapd->own_addr, ETH_ALEN) == 0) {
- + /* Do not process any frames with unexpected/invalid SA so that
- + * we do not add any state for unexpected STA addresses or end
- + * up sending out frames to unexpected destination. */
- + wpa_printf(MSG_DEBUG, "%s: Invalid SA=" MACSTR
- + " in received indication - ignore this indication silently",
- + __func__, MAC2STR(addr));
- + return 0;
- + }
- +
- random_add_randomness(addr, ETH_ALEN);
-
- hostapd_logger(hapd, addr, HOSTAPD_MODULE_IEEE80211,
- diff --git a/src/ap/ieee802_11.c b/src/ap/ieee802_11.c
- index c85a28db44b7..e7065372e158 100644
- --- a/src/ap/ieee802_11.c
- +++ b/src/ap/ieee802_11.c
- @@ -4626,6 +4626,18 @@ int ieee802_11_mgmt(struct hostapd_data *hapd, const u8 *buf, size_t len,
- fc = le_to_host16(mgmt->frame_control);
- stype = WLAN_FC_GET_STYPE(fc);
-
- + if (is_multicast_ether_addr(mgmt->sa) ||
- + is_zero_ether_addr(mgmt->sa) ||
- + os_memcmp(mgmt->sa, hapd->own_addr, ETH_ALEN) == 0) {
- + /* Do not process any frames with unexpected/invalid SA so that
- + * we do not add any state for unexpected STA addresses or end
- + * up sending out frames to unexpected destination. */
- + wpa_printf(MSG_DEBUG, "MGMT: Invalid SA=" MACSTR
- + " in received frame - ignore this frame silently",
- + MAC2STR(mgmt->sa));
- + return 0;
- + }
- +
- if (stype == WLAN_FC_STYPE_BEACON) {
- handle_beacon(hapd, mgmt, len, fi);
- return 1;
- --
- 2.20.1
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