From 6b8cc14723024bbdcc8c3eca8785b8c39c58bd9a Mon Sep 17 00:00:00 2001
From: Isaac Connor <isaac@zoneminder.com>
Date: Mon, 31 Jan 2022 12:07:09 -0500
Subject: [PATCH] Don't free image data if we added the packet to an event. The
 lock moves to the event so it's not safe

---
 src/zm_monitor.cpp | 43 +++++++++++++++++++++++--------------------
 1 file changed, 23 insertions(+), 20 deletions(-)

diff --git a/src/zm_monitor.cpp b/src/zm_monitor.cpp
index b55d2f91d..2c56ec6fe 100644
--- a/src/zm_monitor.cpp
+++ b/src/zm_monitor.cpp
@@ -2270,24 +2270,6 @@ bool Monitor::Analyse() {
       shared_data->state = state = IDLE;
     } // end if ( trigger_data->trigger_state != TRIGGER_OFF )
 
-    if (event) event->AddPacket(packet_lock);
-
-    // In the case where people have pre-alarm frames, the web ui will generate the frame images
-    // from the mp4. So no one will notice anyways.
-    if (snap->image and (videowriter == PASSTHROUGH)) {
-      if (!savejpegs) {
-        Debug(1, "Deleting image data for %d", snap->image_index);
-        // Don't need raw images anymore
-        delete snap->image;
-        snap->image = nullptr;
-      }
-      if (snap->analysis_image and !(savejpegs & 2)) {
-        Debug(1, "Deleting analysis image data for %d", snap->image_index);
-        delete snap->analysis_image;
-        snap->analysis_image = nullptr;
-      }
-    }
-
     packetqueue.clearPackets(snap);
 
     if (snap->codec_type == AVMEDIA_TYPE_VIDEO) {
@@ -2295,9 +2277,30 @@ bool Monitor::Analyse() {
       shared_data->last_read_index = snap->image_index;
       analysis_image_count++;
     }
-    packetqueue.increment_it(analysis_it);
-    if (!event) delete packet_lock;
+
+    if (event) {
+      event->AddPacket(packet_lock);
+    } else {
+      // In the case where people have pre-alarm frames, the web ui will generate the frame images
+      // from the mp4. So no one will notice anyways.
+      if (snap->image and (videowriter == PASSTHROUGH)) {
+        if (!savejpegs) {
+          Debug(1, "Deleting image data for %d", snap->image_index);
+          // Don't need raw images anymore
+          delete snap->image;
+          snap->image = nullptr;
+        }
+        if (snap->analysis_image and !(savejpegs & 2)) {
+          Debug(1, "Deleting analysis image data for %d", snap->image_index);
+          delete snap->analysis_image;
+          snap->analysis_image = nullptr;
+        }
+      }
+      delete packet_lock;
+    }
   } // end scope for event_lock
+
+  packetqueue.increment_it(analysis_it);
   //packetqueue.unlock(packet_lock);
   shared_data->last_read_time = std::chrono::system_clock::to_time_t(std::chrono::system_clock::now());