From 72613d06a5f152af9a4d745abba7da33d01060e3 Mon Sep 17 00:00:00 2001
From: John Reiser <jreiser@BitWagon.com>
Date: Tue, 11 Oct 2022 08:08:55 -0700
Subject: [PATCH] Look for PackHeader in the right place.

https://github.com/upx/upx/issues/606
	modified:   p_mach.cpp
---
 src/p_mach.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/p_mach.cpp b/src/p_mach.cpp
index 6eb0daa6..7925b90d 100644
--- a/src/p_mach.cpp
+++ b/src/p_mach.cpp
@@ -1724,7 +1724,7 @@ int PackMachBase<T>::canUnpack()
     }
 
     int const small = 32 + sizeof(overlay_offset);
-    unsigned bufsize = 4096;
+    unsigned bufsize = 4096 + sizeof(PackHeader);
     if (391 == style) { // PackHeader precedes __LINKEDIT
         fi->seek(offLINK - bufsize, SEEK_SET);
     } else
@@ -1740,7 +1740,7 @@ int PackMachBase<T>::canUnpack()
         }
     } else
     if (395 == style) {
-        fi->seek(offLINK - bufsize - sizeof(PackHeader), SEEK_SET);
+        fi->seek(offLINK - bufsize, SEEK_SET);
     }
     MemBuffer buf(bufsize);
     MemBuffer buf3(bufsize);