ACS: More consistent checking of the best channel pointer

It looks like best might be NULL in some cases, so check for this
explicitly before trying to dereference it for a debug print.

Fixes: 733de85680a4 ("ACS: Fix not selecting the best channel in the segment")
Signed-off-by: Jouni Malinen <quic_jouni@quicinc.com>

diff --git a/src/ap/acs.c b/src/ap/acs.c
index 7da95d6c2dcd227d6539e99abb7aa4de464a6b89..28b0ba71cc7b50360d218c7e6a06db2861c8daa0 100644 (file)
--- a/src/ap/acs.c
+++ b/src/ap/acs.c
@@ -963,7 +963,7 @@ acs_find_ideal_chan_mode(struct hostapd_iface *iface,
                 * crowded primary channel if one was found in the segment */
                if (iface->current_mode &&
                    iface->current_mode->mode == HOSTAPD_MODE_IEEE80211A &&
-                   chan != best) {
+                   best && chan != best) {
                        wpa_printf(MSG_DEBUG,
                                   "ACS: promoting channel %d over %d (less interference %Lg/%Lg)",
                                   best->chan, chan->chan,