diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp
--- a/llvm/lib/Object/MachOObjectFile.cpp
+++ b/llvm/lib/Object/MachOObjectFile.cpp
@@ -191,7 +191,8 @@
 getLoadCommandInfo(const MachOObjectFile &Obj, const char *Ptr,
                    uint32_t LoadCommandIndex) {
   if (auto CmdOrErr = getStructOrErr<MachO::load_command>(Obj, Ptr)) {
-    if (CmdOrErr->cmdsize + Ptr > Obj.getData().end())
+    uint64_t Offset = Ptr - Obj.getData().begin();
+    if (CmdOrErr->cmdsize + Offset > Obj.getData().size())
       return malformedError("load command " + Twine(LoadCommandIndex) +
                             " extends past end of file");
     if (CmdOrErr->cmdsize < 8)