From 4aaac5d65e6bf8b412d1295c7d3439aa86632ced Mon Sep 17 00:00:00 2001
From: Steve Lhomme <robux4@ycbcr.xyz>
Date: Thu, 30 Apr 2026 16:28:00 +0200
Subject: [PATCH] EbmlMaster: exit reading loop if upper element found ends
 after its parent

It could be a file with missing data in the middle.
And we shouldn't use a MaxSizeToRead that would be negative.
---
 src/EbmlMaster.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/EbmlMaster.cpp b/src/EbmlMaster.cpp
index 5f210ff0..d91ab06e 100644
--- a/src/EbmlMaster.cpp
+++ b/src/EbmlMaster.cpp
@@ -470,6 +470,9 @@ void EbmlMaster::Read(EbmlStream & inDataStream, const EbmlSemanticContext & sCo
         }
         ElementLevelA = FoundElt;
         if (IsFiniteSize() && ElementLevelA->IsFiniteSize()) {
+          if (ElementLevelA->GetEndPosition() > GetEndPosition()) {
+            goto processCrc; // found an upper element that ends after this, we were truncated
+          }
           MaxSizeToRead = GetEndPosition() - ElementLevelA->GetEndPosition(); // even if it's the default value
         }
         continue;