diff --git a/compiler-rt/lib/scudo/standalone/combined.h b/compiler-rt/lib/scudo/standalone/combined.h
--- a/compiler-rt/lib/scudo/standalone/combined.h
+++ b/compiler-rt/lib/scudo/standalone/combined.h
@@ -22,7 +22,7 @@
 #include "tsd.h"
 
 #ifdef GWP_ASAN_HOOKS
-# include "gwp_asan/guarded_pool_allocator.h"
+#include "gwp_asan/guarded_pool_allocator.h"
 // GWP-ASan is declared here in order to avoid indirect call overhead. It's also
 // instantiated outside of the Allocator class, as the allocator is only
 // zero-initialised. GWP-ASan requires constant initialisation, and the Scudo
@@ -414,19 +414,19 @@
     return NewPtr;
   }
 
-  // TODO(kostyak): while this locks the Primary & Secondary, it still allows
-  //                pointers to be fetched from the TSD. We ultimately want to
-  //                lock the registry as well. For now, it's good enough.
+  // TODO(kostyak): disable() is currently best-effort. There are some small
+  //                windows of time when an allocation could still succeed after
+  //                this function finishes. We will revisit that later.
   void disable() {
     initThreadMaybe();
-    Primary.disable();
+    TSDRegistry.disable();
     Secondary.disable();
   }
 
   void enable() {
     initThreadMaybe();
     Secondary.enable();
-    Primary.enable();
+    TSDRegistry.enable();
   }
 
   // The function returns the amount of bytes required to store the statistics,
diff --git a/compiler-rt/lib/scudo/standalone/flags.cpp b/compiler-rt/lib/scudo/standalone/flags.cpp
--- a/compiler-rt/lib/scudo/standalone/flags.cpp
+++ b/compiler-rt/lib/scudo/standalone/flags.cpp
@@ -40,7 +40,7 @@
 
 #ifdef GWP_ASAN_HOOKS
 #define GWP_ASAN_OPTION(Type, Name, DefaultValue, Description)                 \
-  Parser->registerFlag("GWP_ASAN_"#Name, Description, FlagType::FT_##Type,     \
+  Parser->registerFlag("GWP_ASAN_" #Name, Description, FlagType::FT_##Type,    \
                        reinterpret_cast<void *>(&F->GWP_ASAN_##Name));
 #include "gwp_asan/options.inc"
 #undef GWP_ASAN_OPTION
diff --git a/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp b/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp
--- a/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp
+++ b/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp
@@ -284,6 +284,21 @@
   free(P);
 }
 
+// We expect heap operations within a disable/enable scope to deadlock.
+TEST(ScudoWrappersCTest, MallocDisableDeadlock) {
+  EXPECT_DEATH(
+      {
+        void *P = malloc(Size);
+        EXPECT_NE(P, nullptr);
+        free(P);
+        malloc_disable();
+        alarm(1);
+        P = malloc(Size);
+        malloc_enable();
+      },
+      "");
+}
+
 #if !SCUDO_FUCHSIA
 TEST(ScudoWrappersCTest, MallocInfo) {
   char Buffer[64];
diff --git a/compiler-rt/lib/scudo/standalone/tsd_exclusive.h b/compiler-rt/lib/scudo/standalone/tsd_exclusive.h
--- a/compiler-rt/lib/scudo/standalone/tsd_exclusive.h
+++ b/compiler-rt/lib/scudo/standalone/tsd_exclusive.h
@@ -48,7 +48,8 @@
   }
 
   ALWAYS_INLINE TSD<Allocator> *getTSDAndLock(bool *UnlockRequired) {
-    if (LIKELY(State == ThreadState::Initialized)) {
+    if (LIKELY(State == ThreadState::Initialized &&
+               !atomic_load(&Disabled, memory_order_acquire))) {
       *UnlockRequired = false;
       return &ThreadTSD;
     }
@@ -58,6 +59,18 @@
     return FallbackTSD;
   }
 
+  // To disable the exclusive TSD registry, we effectively lock the fallback TSD
+  // and force all threads to attempt to use it instead of their local one.
+  void disable() {
+    FallbackTSD->lock();
+    atomic_store(&Disabled, 1U, memory_order_release);
+  }
+
+  void enable() {
+    atomic_store(&Disabled, 0U, memory_order_release);
+    FallbackTSD->unlock();
+  }
+
 private:
   void initOnceMaybe(Allocator *Instance) {
     ScopedLock L(Mutex);
@@ -81,6 +94,7 @@
 
   pthread_key_t PThreadKey;
   bool Initialized;
+  atomic_u8 Disabled;
   TSD<Allocator> *FallbackTSD;
   HybridMutex Mutex;
   static THREADLOCAL ThreadState State;
diff --git a/compiler-rt/lib/scudo/standalone/tsd_shared.h b/compiler-rt/lib/scudo/standalone/tsd_shared.h
--- a/compiler-rt/lib/scudo/standalone/tsd_shared.h
+++ b/compiler-rt/lib/scudo/standalone/tsd_shared.h
@@ -72,6 +72,16 @@
     return getTSDAndLockSlow(TSD);
   }
 
+  void disable() {
+    for (u32 I = 0; I < NumberOfTSDs; I++)
+      TSDs[I].lock();
+  }
+
+  void enable() {
+    for (u32 I = 0; I < NumberOfTSDs; I++)
+      TSDs[I].unlock();
+  }
+
 private:
   ALWAYS_INLINE void setCurrentTSD(TSD<Allocator> *CurrentTSD) {
 #if _BIONIC