[openwrt/openwrt] hostapd: add missing NULL pointer check on radar notification

[LEDE Commits]

nbd pushed a commit to openwrt/openwrt.git, branch openwrt-23.05:
https://git.openwrt.org/9cd0023e54adf8b06762c58585b7cb225e5fb2d6

commit 9cd0023e54adf8b06762c58585b7cb225e5fb2d6
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Tue Jan 9 11:05:45 2024 +0100

    hostapd: add missing NULL pointer check on radar notification
    
    Fixes a race condition that can lead to a hostapd crash
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
    (cherry picked from commit d864f68232e910f2c8ab06a66347fc08c257dfcc)
---
 package/network/services/hostapd/src/src/ap/ubus.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/package/network/services/hostapd/src/src/ap/ubus.c b/package/network/services/hostapd/src/src/ap/ubus.c
index 6ff2257c32..66eba99901 100644
--- a/package/network/services/hostapd/src/src/ap/ubus.c
+++ b/package/network/services/hostapd/src/src/ap/ubus.c
@@ -1907,6 +1907,9 @@ void hostapd_ubus_notify_radar_detected(struct hostapd_iface *iface, int frequen
 	struct hostapd_data *hapd;
 	int i;
 
+	if (!ctx)
+		return;
+
 	blob_buf_init(&b, 0);
 	blobmsg_add_u16(&b, "frequency", frequency);
 	blobmsg_add_u16(&b, "width", chan_width);