[PATCH] AP: Fix a crash in hostapd_driver_init()

[Andrei Otcheretianski]

In case of MLD AP it is assumed that the multi link information
(hapd->mld) is already initialized by the time this function is called.
However, if the interface is added without bss_config parameter,
hostapd_bss_setup_multi_link() would bail out immediately as mld_ap
parameter isn't set yet.
When the interface gets enabled later, hapd->mld would be NULL resulting
in NULL dereference.

Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski at intel.com>
---
 hostapd/main.c   | 5 ++++-
 src/ap/hostapd.c | 4 ++--
 src/ap/hostapd.h | 2 ++
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/hostapd/main.c b/hostapd/main.c
index 512cd892bd..72bf324448 100644
--- a/hostapd/main.c
+++ b/hostapd/main.c
@@ -168,8 +168,11 @@ static int hostapd_driver_init(struct hostapd_iface *iface)
 	}
 
 #ifdef CONFIG_IEEE80211BE
-	if (conf->mld_ap)
+	if (conf->mld_ap) {
+		if (!hapd->mld)
+			hostapd_bss_setup_multi_link(hapd, iface->interfaces);
 		h_hapd = hostapd_mld_get_first_bss(hapd);
+	}
 
 	if (h_hapd) {
 		hapd->drv_priv = h_hapd->drv_priv;
diff --git a/src/ap/hostapd.c b/src/ap/hostapd.c
index f97311587d..23bff4ffa6 100644
--- a/src/ap/hostapd.c
+++ b/src/ap/hostapd.c
@@ -3080,8 +3080,8 @@ static void hostapd_bss_alloc_link_id(struct hostapd_data *hapd)
 #endif /* CONFIG_IEEE80211BE */
 
 
-static void hostapd_bss_setup_multi_link(struct hostapd_data *hapd,
-					 struct hapd_interfaces *interfaces)
+void hostapd_bss_setup_multi_link(struct hostapd_data *hapd,
+				  struct hapd_interfaces *interfaces)
 {
 #ifdef CONFIG_IEEE80211BE
 	struct hostapd_mld *mld, **all_mld;
diff --git a/src/ap/hostapd.h b/src/ap/hostapd.h
index dddefb593c..dabca24efc 100644
--- a/src/ap/hostapd.h
+++ b/src/ap/hostapd.h
@@ -766,6 +766,8 @@ struct hostapd_iface * hostapd_init(struct hapd_interfaces *interfaces,
 struct hostapd_iface *
 hostapd_interface_init_bss(struct hapd_interfaces *interfaces, const char *phy,
 			   const char *config_fname, int debug);
+void hostapd_bss_setup_multi_link(struct hostapd_data *hapd,
+				  struct hapd_interfaces *interfaces);
 void hostapd_new_assoc_sta(struct hostapd_data *hapd, struct sta_info *sta,
 			   int reassoc);
 void hostapd_interface_deinit_free(struct hostapd_iface *iface);
-- 
2.43.0