cfg80211: fix WoWLAN wakeup tracing

If the device reports a non-wireless wakeup reason, the
tracing code crashes trying to dereference a NULL pointer.
Fix this by checking the pointer on all accesses and also
add a non_wireless tag to the event.

Cc: stable@vger.kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 13 insertions, 10 deletions

diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index ecd4fcec3c94..5755bc14abbd 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -2441,6 +2441,7 @@ TRACE_EVENT(cfg80211_report_wowlan_wakeup,
         TP_STRUCT__entry(
                 WIPHY_ENTRY
                 WDEV_ENTRY
+                __field(bool, non_wireless)
                 __field(bool, disconnect)
                 __field(bool, magic_pkt)
                 __field(bool, gtk_rekey_failure)
@@ -2449,20 +2450,22 @@ TRACE_EVENT(cfg80211_report_wowlan_wakeup,
                 __field(bool, rfkill_release)
                 __field(s32, pattern_idx)
                 __field(u32, packet_len)
-                __dynamic_array(u8, packet, wakeup->packet_present_len)
+                __dynamic_array(u8, packet,
+                                wakeup ? wakeup->packet_present_len : 0)
         ),
         TP_fast_assign(
                 WIPHY_ASSIGN;
                 WDEV_ASSIGN;
-                __entry->disconnect = wakeup->disconnect;
-                __entry->magic_pkt = wakeup->magic_pkt;
-                __entry->gtk_rekey_failure = wakeup->gtk_rekey_failure;
-                __entry->eap_identity_req = wakeup->eap_identity_req;
-                __entry->four_way_handshake = wakeup->four_way_handshake;
-                __entry->rfkill_release = wakeup->rfkill_release;
-                __entry->pattern_idx = wakeup->pattern_idx;
-                __entry->packet_len = wakeup->packet_len;
-                if (wakeup->packet && wakeup->packet_present_len)
+                __entry->non_wireless = !wakeup;
+                __entry->disconnect = wakeup ? wakeup->disconnect : false;
+                __entry->magic_pkt = wakeup ? wakeup->magic_pkt : false;
+                __entry->gtk_rekey_failure = wakeup ? wakeup->gtk_rekey_failure : false;
+                __entry->eap_identity_req = wakeup ? wakeup->eap_identity_req : false;
+                __entry->four_way_handshake = wakeup ? wakeup->four_way_handshake : false;
+                __entry->rfkill_release = wakeup ? wakeup->rfkill_release : false;
+                __entry->pattern_idx = wakeup ? wakeup->pattern_idx : false;
+                __entry->packet_len = wakeup ? wakeup->packet_len : false;
+                if (wakeup && wakeup->packet && wakeup->packet_present_len)
                         memcpy(__get_dynamic_array(packet), wakeup->packet,
                                wakeup->packet_present_len);
         ),