[PATCH] Three bugfixes for iwd SEGVs at receipt of EAPOL M1 msg with legacy roaming and repeated roam scan after ft_auth-/ft_reassoc-timeout occurred:

[dierk.modrow.opensource@gmail.com]

From: DEMODDIE <dierk.modrow@sew-eurodrive.de>

  src/eapol.c: next try for a fix of SEGV fault at eapol_rx_packets when using mwifiex / NXP 88W9098 driver
  src/station.c: potential bugfix in station_roam_scan_notify to avoid NULL-Ptr access to var hs
  src/station.c: next try to fix a SEGV after auth timeout at FT roaming
---
 src/eapol.c   |  4 ++++
 src/station.c | 12 ++++++------
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/src/eapol.c b/src/eapol.c
index 372549c6..c2dc4e4c 100644
--- a/src/eapol.c
+++ b/src/eapol.c
@@ -2824,6 +2824,10 @@ void eapol_register(struct eapol_sm *sm)
 
 	l_queue_push_head(state_machines, sm);
 
+	/* workaround against SEGV on fct. eapol_rx_packet by avoiding for two different eapol_frame_watches with different ids, but same eapol_sm ptr */
+	if ((sm->watch_id > 0) && eapol_frame_watch_remove(sm->watch_id)) {
+		l_debug("existing frame_watch for sm=%p with id=%u successfully removed", sm, sm->watch_id);
+	}
 	sm->watch_id = eapol_frame_watch_add(sm->handshake->ifindex,
 						rx_handler, sm);
 	sm->protocol_version = sm->handshake->proto_version;
diff --git a/src/station.c b/src/station.c
index 8fcf8c70..077e510e 100644
--- a/src/station.c
+++ b/src/station.c
@@ -2253,7 +2253,7 @@ static bool station_can_fast_transition(struct station *station,
 {
 	uint16_t mdid;
 
-	if (!hs->mde)
+	if (!hs || !hs->mde)
 		return false;
 
 	if (ie_parse_mobility_domain_from_data(hs->mde, hs->mde[1] + 2,
@@ -2917,7 +2917,7 @@ static bool station_roam_scan_notify(int err, struct l_queue *bss_list,
 
 	orig_security = network_get_security(network);
 
-	if (hs->mde)
+	if (hs && hs->mde)
 		ie_parse_mobility_domain_from_data(hs->mde, hs->mde[1] + 2,
 							&mdid, NULL, NULL);
 
@@ -2930,7 +2930,7 @@ static bool station_roam_scan_notify(int err, struct l_queue *bss_list,
 	if (bss && !station->ap_directed_roaming) {
 		double cur_bss_rank = bss->rank;
 
-		if (hs->mde && bss->mde_present && l_get_le16(bss->mde) == mdid)
+		if (hs && hs->mde && bss->mde_present && l_get_le16(bss->mde) == mdid)
 			cur_bss_rank *= RANK_FT_FACTOR;
 
 		cur_bss_group_rank = evaluate_bss_group_rank(bss->addr,
@@ -2967,8 +2967,8 @@ static bool station_roam_scan_notify(int err, struct l_queue *bss_list,
 			goto next;
 
 		/* Skip result if it is not part of the ESS */
-		if (bss->ssid_len != hs->ssid_len ||
-				memcmp(bss->ssid, hs->ssid, hs->ssid_len))
+		if (hs && (bss->ssid_len != hs->ssid_len ||
+				memcmp(bss->ssid, hs->ssid, hs->ssid_len)))
 			goto next;
 
 		if (scan_bss_get_security(bss, &security) < 0)
@@ -2986,7 +2986,7 @@ static bool station_roam_scan_notify(int err, struct l_queue *bss_list,
 
 		rank = bss->rank;
 
-		if (hs->mde && bss->mde_present && l_get_le16(bss->mde) == mdid)
+		if (hs && hs->mde && bss->mde_present && l_get_le16(bss->mde) == mdid)
 			rank *= RANK_FT_FACTOR;
 
 		group_rank = evaluate_bss_group_rank(bss->addr, bss->frequency,
-- 
2.53.0.windows.2