Index: include/clang/Basic/Features.def
===================================================================
--- include/clang/Basic/Features.def
+++ include/clang/Basic/Features.def
@@ -72,7 +72,9 @@
 FEATURE(enumerator_attributes, true)
 FEATURE(nullability, true)
 FEATURE(nullability_on_arrays, true)
-FEATURE(memory_sanitizer, LangOpts.Sanitize.has(SanitizerKind::Memory))
+FEATURE(memory_sanitizer,
+        LangOpts.Sanitize.hasOneOf(SanitizerKind::Memory |
+                                   SanitizerKind::KernelMemory))
 FEATURE(thread_sanitizer, LangOpts.Sanitize.has(SanitizerKind::Thread))
 FEATURE(dataflow_sanitizer, LangOpts.Sanitize.has(SanitizerKind::DataFlow))
 FEATURE(efficiency_sanitizer,
Index: include/clang/Basic/Sanitizers.def
===================================================================
--- include/clang/Basic/Sanitizers.def
+++ include/clang/Basic/Sanitizers.def
@@ -53,6 +53,9 @@
 // MemorySanitizer
 SANITIZER("memory", Memory)
 
+// Kernel MemorySanitizer (KMSAN)
+SANITIZER("kernel-memory", KernelMemory)
+
 // libFuzzer
 SANITIZER("fuzzer", Fuzzer)
 
Index: lib/CodeGen/BackendUtil.cpp
===================================================================
--- lib/CodeGen/BackendUtil.cpp
+++ lib/CodeGen/BackendUtil.cpp
@@ -265,14 +265,15 @@
       /*CompileKernel*/ true, /*Recover*/ true));
 }
 
-static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
-                                   legacy::PassManagerBase &PM) {
+static void addGeneralOptsForMemorySanitizer(const PassManagerBuilder &Builder,
+                                             legacy::PassManagerBase &PM,
+                                             bool CompileKernel) {
   const PassManagerBuilderWrapper &BuilderWrapper =
       static_cast<const PassManagerBuilderWrapper&>(Builder);
   const CodeGenOptions &CGOpts = BuilderWrapper.getCGOpts();
   int TrackOrigins = CGOpts.SanitizeMemoryTrackOrigins;
   bool Recover = CGOpts.SanitizeRecover.has(SanitizerKind::Memory);
-  PM.add(createMemorySanitizerPass(TrackOrigins, Recover));
+  PM.add(createMemorySanitizerPass(TrackOrigins, Recover, CompileKernel));
 
   // MemorySanitizer inserts complex instrumentation that mostly follows
   // the logic of the original code, but operates on "shadow" values.
@@ -287,6 +288,16 @@
   }
 }
 
+static void addMemorySanitizerPass(const PassManagerBuilder &Builder,
+                                   legacy::PassManagerBase &PM) {
+  addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ false);
+}
+
+static void addKernelMemorySanitizerPass(const PassManagerBuilder &Builder,
+                                         legacy::PassManagerBase &PM) {
+  addGeneralOptsForMemorySanitizer(Builder, PM, /*CompileKernel*/ true);
+}
+
 static void addThreadSanitizerPass(const PassManagerBuilder &Builder,
                                    legacy::PassManagerBase &PM) {
   PM.add(createThreadSanitizerPass());
@@ -613,6 +624,13 @@
                            addMemorySanitizerPass);
   }
 
+  if (LangOpts.Sanitize.has(SanitizerKind::KernelMemory)) {
+    PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
+                           addKernelMemorySanitizerPass);
+    PMBuilder.addExtension(PassManagerBuilder::EP_EnabledOnOptLevel0,
+                           addKernelMemorySanitizerPass);
+  }
+
   if (LangOpts.Sanitize.has(SanitizerKind::Thread)) {
     PMBuilder.addExtension(PassManagerBuilder::EP_OptimizerLast,
                            addThreadSanitizerPass);
Index: lib/CodeGen/CGDeclCXX.cpp
===================================================================
--- lib/CodeGen/CGDeclCXX.cpp
+++ lib/CodeGen/CGDeclCXX.cpp
@@ -347,6 +347,10 @@
       !isInSanitizerBlacklist(SanitizerKind::Memory, Fn, Loc))
     Fn->addFnAttr(llvm::Attribute::SanitizeMemory);
 
+  if (getLangOpts().Sanitize.has(SanitizerKind::KernelMemory) &&
+      !isInSanitizerBlacklist(SanitizerKind::KernelMemory, Fn, Loc))
+    Fn->addFnAttr(llvm::Attribute::SanitizeMemory);
+
   if (getLangOpts().Sanitize.has(SanitizerKind::SafeStack) &&
       !isInSanitizerBlacklist(SanitizerKind::SafeStack, Fn, Loc))
     Fn->addFnAttr(llvm::Attribute::SafeStack);
Index: lib/CodeGen/CodeGenFunction.cpp
===================================================================
--- lib/CodeGen/CodeGenFunction.cpp
+++ lib/CodeGen/CodeGenFunction.cpp
@@ -866,7 +866,7 @@
     Fn->addFnAttr(llvm::Attribute::SanitizeHWAddress);
   if (SanOpts.has(SanitizerKind::Thread))
     Fn->addFnAttr(llvm::Attribute::SanitizeThread);
-  if (SanOpts.has(SanitizerKind::Memory))
+  if (SanOpts.hasOneOf(SanitizerKind::Memory | SanitizerKind::KernelMemory))
     Fn->addFnAttr(llvm::Attribute::SanitizeMemory);
   if (SanOpts.has(SanitizerKind::SafeStack))
     Fn->addFnAttr(llvm::Attribute::SafeStack);
Index: lib/Driver/SanitizerArgs.cpp
===================================================================
--- lib/Driver/SanitizerArgs.cpp
+++ lib/Driver/SanitizerArgs.cpp
@@ -34,8 +34,9 @@
   RequiresPIE = DataFlow | HWAddress | Scudo,
   NeedsUnwindTables = Address | HWAddress | Thread | Memory | DataFlow,
   SupportsCoverage = Address | HWAddress | KernelAddress | KernelHWAddress |
-                     Memory | Leak | Undefined | Integer | ImplicitConversion |
-                     Nullability | DataFlow | Fuzzer | FuzzerNoLink,
+                     Memory | KernelMemory | Leak | Undefined | Integer |
+                     ImplicitConversion | Nullability | DataFlow | Fuzzer |
+                     FuzzerNoLink,
   RecoverableByDefault = Undefined | Integer | ImplicitConversion | Nullability,
   Unrecoverable = Unreachable | Return,
   AlwaysRecoverable = KernelAddress | KernelHWAddress,
@@ -380,8 +381,10 @@
                                           SafeStack),
       std::make_pair(KernelHWAddress, Address | HWAddress | Leak | Thread |
                                           Memory | KernelAddress | Efficiency |
-                                          SafeStack | ShadowCallStack)};
-
+                                          SafeStack | ShadowCallStack),
+      std::make_pair(KernelMemory, Address | HWAddress | Leak | Thread |
+                                       Memory | KernelAddress | Efficiency |
+                                       Scudo | SafeStack)};
   // Enable toolchain specific default sanitizers if not explicitly disabled.
   SanitizerMask Default = TC.getDefaultSanitizers() & ~AllRemove;
 
Index: lib/Driver/ToolChains/Linux.cpp
===================================================================
--- lib/Driver/ToolChains/Linux.cpp
+++ lib/Driver/ToolChains/Linux.cpp
@@ -934,6 +934,8 @@
     Res |= SanitizerKind::Leak;
   if (IsX86_64 || IsMIPS64 || IsAArch64 || IsPowerPC64)
     Res |= SanitizerKind::Thread;
+  if (IsX86_64)
+    Res |= SanitizerKind::KernelMemory;
   if (IsX86_64 || IsMIPS64)
     Res |= SanitizerKind::Efficiency;
   if (IsX86 || IsX86_64)
Index: lib/Frontend/CompilerInvocation.cpp
===================================================================
--- lib/Frontend/CompilerInvocation.cpp
+++ lib/Frontend/CompilerInvocation.cpp
@@ -3064,7 +3064,9 @@
   // names.
   Res.getCodeGenOpts().DiscardValueNames &=
       !LangOpts.Sanitize.has(SanitizerKind::Address) &&
-      !LangOpts.Sanitize.has(SanitizerKind::Memory);
+      !LangOpts.Sanitize.has(SanitizerKind::KernelAddress) &&
+      !LangOpts.Sanitize.has(SanitizerKind::Memory) &&
+      !LangOpts.Sanitize.has(SanitizerKind::KernelMemory);
 
   ParsePreprocessorArgs(Res.getPreprocessorOpts(), Args, Diags,
                         Res.getFrontendOpts().ProgramAction);