Index: lib/ReaderWriter/MachO/ArchHandler.cpp
===================================================================
--- lib/ReaderWriter/MachO/ArchHandler.cpp
+++ lib/ReaderWriter/MachO/ArchHandler.cpp
@@ -142,6 +142,8 @@
 
 bool ArchHandler::isDwarfCIE(bool isBig, const DefinedAtom *atom) {
   assert(atom->contentType() == DefinedAtom::typeCFI);
+  if (atom->rawContent().size() < sizeof(uint32_t))
+    return false;
   uint32_t size = read32(atom->rawContent().data(), isBig);
 
   uint32_t idOffset = sizeof(uint32_t);
Index: lib/ReaderWriter/MachO/CompactUnwindPass.cpp
===================================================================
--- lib/ReaderWriter/MachO/CompactUnwindPass.cpp
+++ lib/ReaderWriter/MachO/CompactUnwindPass.cpp
@@ -411,6 +411,9 @@
       }
     }
 
+    if (atom->rawContent().size() < 4 * sizeof(uint32_t))
+      return entry;
+
     using normalized::read32;
     entry.rangeLength =
         read32(atom->rawContent().data() + 2 * sizeof(uint32_t), _isBig);