From 6b7486db9927a1b3f6dd9cc84dff54c33a8aef8c Mon Sep 17 00:00:00 2001
From: Rod Smith <rodsmith@rodsbooks.com>
Date: Sun, 10 Apr 2022 10:25:41 -0400
Subject: Abort load of too-small disk image

---
 gpt.cc | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

(limited to 'gpt.cc')

diff --git a/gpt.cc b/gpt.cc
index 5ccc5c5..848340b 100644
--- a/gpt.cc
+++ b/gpt.cc
@@ -886,8 +886,16 @@ int GPTData::LoadPartitions(const string & deviceFilename) {
             break;
       } // switch
 
-      if (allOK)
+      if (allOK) {
          CheckGPTSize();
+         // Below is unlikely to happen on real disks, but could happen if
+         // the user is manipulating a truncated image file....
+         if (diskSize <= GetTableSizeInSectors() * 2 + 3) {
+             allOK = 0;
+             cout << "Disk is too small to hold GPT data (" << diskSize
+                  << " sectors)! Aborting!\n";
+         }
+      }
       myDisk.Close();
       ComputeAlignment();
    } else {
-- 
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