Index: ELF/ScriptParser.cpp
===================================================================
--- ELF/ScriptParser.cpp
+++ ELF/ScriptParser.cpp
@@ -889,7 +889,7 @@
   if (S == "MAXPAGESIZE")
     return [] { return Config->MaxPageSize; };
   setError("unknown constant: " + S);
-  return {};
+  return [] { return 0; };
 }
 
 // Parses Tok as an integer. It recognizes hexadecimal (prefixed with
@@ -1052,8 +1052,10 @@
   }
   if (Tok == "LENGTH") {
     StringRef Name = readParenLiteral();
-    if (Script->MemoryRegions.count(Name) == 0)
+    if (Script->MemoryRegions.count(Name) == 0) {
       setError("memory region not defined: " + Name);
+      return [] { return 0; };
+    }
     return [=] { return Script->MemoryRegions[Name]->Length; };
   }
   if (Tok == "LOADADDR") {
@@ -1066,8 +1068,10 @@
   }
   if (Tok == "ORIGIN") {
     StringRef Name = readParenLiteral();
-    if (Script->MemoryRegions.count(Name) == 0)
+    if (Script->MemoryRegions.count(Name) == 0) {
       setError("memory region not defined: " + Name);
+      return [] { return 0; };
+    }
     return [=] { return Script->MemoryRegions[Name]->Origin; };
   }
   if (Tok == "SEGMENT_START") {
Index: test/ELF/linkerscript/broken-memory-declaration.s
===================================================================
--- test/ELF/linkerscript/broken-memory-declaration.s
+++ test/ELF/linkerscript/broken-memory-declaration.s
@@ -0,0 +1,13 @@
+# REQUIRES: x86
+
+## Check we do not crash.
+
+# RUN: echo "MEMORY { FLASH (rx) : ORIGIN = 0x1000< LENGTH" > %t.script
+# RUN: not ld.lld -o %t --script %t.script 2>&1 | FileCheck %s
+# CHECK: unexpected EOF
+
+# RUN: echo "MEMORY { FLASH (rx) : ORIGIN = 0x1000< ORIGIN" > %t.script
+# RUN: not ld.lld -o %t --script %t.script 2>&1 | FileCheck %s
+
+# RUN: echo "MEMORY { FLASH (rx) : ORIGIN = 0x1000, LENGTH = CONSTANT" > %t.script
+# RUN: not ld.lld -o %t --script %t.script 2>&1 | FileCheck %s