diff -Nru firefox-esr-78.13.0esr+build1/BUILDID firefox-esr-78.13.0esr+build2/BUILDID
--- firefox-esr-78.13.0esr+build1/BUILDID	2021-08-02 15:52:25.000000000 +0000
+++ firefox-esr-78.13.0esr+build2/BUILDID	2021-08-05 05:11:49.000000000 +0000
@@ -1 +1 @@
-20210802115006
\ No newline at end of file
+20210804193512
\ No newline at end of file
diff -Nru firefox-esr-78.13.0esr+build1/debian/changelog firefox-esr-78.13.0esr+build2/debian/changelog
--- firefox-esr-78.13.0esr+build1/debian/changelog	2021-08-02 15:40:42.000000000 +0000
+++ firefox-esr-78.13.0esr+build2/debian/changelog	2021-08-05 05:04:59.000000000 +0000
@@ -1,3 +1,9 @@
+firefox-esr (78.13.0esr+build2-0ubuntu0.16.04.1) xenial; urgency=medium
+
+  * New upstream stable release (FIREFOX_78_13_0esr_BUILD2)
+
+ -- Rico Tzschichholz <ricotz@ubuntu.com>  Thu, 05 Aug 2021 07:04:59 +0200
+
 firefox-esr (78.13.0esr+build1-0ubuntu0.16.04.1) xenial; urgency=medium
 
   * New upstream stable release (FIREFOX_78_13_0esr_BUILD1)
diff -Nru firefox-esr-78.13.0esr+build1/dom/media/ChannelMediaResource.cpp firefox-esr-78.13.0esr+build2/dom/media/ChannelMediaResource.cpp
--- firefox-esr-78.13.0esr+build1/dom/media/ChannelMediaResource.cpp	2021-08-02 15:45:01.000000000 +0000
+++ firefox-esr-78.13.0esr+build2/dom/media/ChannelMediaResource.cpp	2021-08-05 05:04:16.000000000 +0000
@@ -640,6 +640,15 @@
 void ChannelMediaResource::CloseChannel() {
   NS_ASSERTION(NS_IsMainThread(), "Only call on main thread");
 
+  // Revoking listener should be done before canceling the channel, because
+  // canceling the channel might cause the input stream to release its buffer.
+  // If we don't do revoke first, it's possible that `OnDataAvailable` would be
+  // called later and then incorrectly access that released buffer.
+  if (mListener) {
+    mListener->Revoke();
+    mListener = nullptr;
+  }
+
   if (mChannel) {
     mSuspendAgent.Revoke();
     // The status we use here won't be passed to the decoder, since
@@ -652,11 +661,6 @@
     mChannel->Cancel(NS_ERROR_PARSED_DATA_CACHED);
     mChannel = nullptr;
   }
-
-  if (mListener) {
-    mListener->Revoke();
-    mListener = nullptr;
-  }
 }
 
 nsresult ChannelMediaResource::ReadFromCache(char* aBuffer, int64_t aOffset,
diff -Nru firefox-esr-78.13.0esr+build1/SOURCE_CHANGESET firefox-esr-78.13.0esr+build2/SOURCE_CHANGESET
--- firefox-esr-78.13.0esr+build1/SOURCE_CHANGESET	2021-08-02 15:45:34.000000000 +0000
+++ firefox-esr-78.13.0esr+build2/SOURCE_CHANGESET	2021-08-05 05:04:48.000000000 +0000
@@ -1 +1 @@
-c1bc34d42814d7b62e2a28a116cc7749b3a13107
\ No newline at end of file
+7d8548789b6c540da86256a96c81cdfe25ae2130
\ No newline at end of file