[PATCH] wpa_supplicant: Don't process EAPOLs while disconnecting

Andrei Otcheretianski andrei.otcheretianski at intel.com
Sun Mar 7 21:40:01 GMT 2021

An EAPOL frame may be pending when the supplicant requests to
deauthenticate. At this stage the EAP SM cache is already cleaned by
calling eapol_sm_invalidate_cached_session(). Since at this stage the
wpa_supplicant's state is still set to associated, the EAPOL is
processed and results in a crash due to NULL dereference.
This wasn't seen previously as nl80211 wouldn't process the
NL80211_CMD_CONTROL_PORT_FRAME, since wpa_driver_nl80211_mlme() would
set the valid_handler to NULL. This behavior was changed in ab8929192
("nl80211: use the process_bss_event for the nl_connect handler"),
exposing this race.
Fix it by ignoring EAPOL frames while the deauthentication is in

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski at intel.com>
 wpa_supplicant/wpa_supplicant.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/wpa_supplicant/wpa_supplicant.c b/wpa_supplicant/wpa_supplicant.c
index 6a02ed7c56..c8dcef21bd 100644
--- a/wpa_supplicant/wpa_supplicant.c
+++ b/wpa_supplicant/wpa_supplicant.c
@@ -4773,6 +4773,11 @@ void wpa_supplicant_rx_eapol(void *ctx, const u8 *src_addr,
 	wpa_dbg(wpa_s, MSG_DEBUG, "RX EAPOL from " MACSTR, MAC2STR(src_addr));
 	wpa_hexdump(MSG_MSGDUMP, "RX EAPOL", buf, len);
+	if (wpa_s->own_disconnect_req) {
+		wpa_printf(MSG_DEBUG, "RX EAPOL - drop EAPOL frame as we are disconnecting");
+		return;
+	}
 	if (wpa_s->ignore_auth_resp) {
 		wpa_printf(MSG_INFO, "RX EAPOL - ignore_auth_resp active!");

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