Index: lib/asan/asan_globals.cc
===================================================================
--- lib/asan/asan_globals.cc
+++ lib/asan/asan_globals.cc
@@ -233,7 +233,7 @@
   }
 }
 
-static void UnregisterGlobal(const Global *g) {
+static void UnregisterGlobal(const Global *g, ListOfGlobals **prev_list) {
   CHECK(asan_inited);
   if (flags()->report_globals >= 2)
     ReportGlobal(*g, "Removed");
@@ -243,9 +243,35 @@
   CHECK(AddrIsAlignedByGranularity(g->size_with_redzone));
   if (CanPoisonMemory())
     PoisonShadowForGlobal(g, 0);
-  // We unpoison the shadow memory for the global but we do not remove it from
-  // the list because that would require O(n^2) time with the current list
-  // implementation. It might not be worth doing anyway.
+
+  // We unpoisoned the shadow memory for the global and remove it from the list
+  // of globals to prevent GetGlobalsForAddress from accessing unmapped memory.
+  ListOfGlobals *l;
+  if (*prev_list && (l = (*prev_list)->next) && l->g == g) {
+    // Optimization: when an array of globals is unregistered, the items to be
+    // removed succeed each other so take advantage of that.
+    (*prev_list)->next = l->next;
+  } else {
+    // The start node in the list is initially unknown, so try to find it.
+    ListOfGlobals *last_l = nullptr;
+    for (ListOfGlobals *l = list_of_all_globals; l; l = l->next) {
+      if (l->g == g) {
+        // Found the global, now unlink it from the list and remember the
+        // position for the next UnregisterGlobal call.
+        if (last_l) {
+          last_l->next = l->next;
+          *prev_list = last_l;
+        } else {
+          list_of_all_globals = l->next;
+          *prev_list = nullptr;
+        }
+        // Allocator for 'l' does not have a delete operator, just leak it.
+        break;
+      } else {
+        last_l = l;
+      }
+    }
+  }
 
   // Release ODR indicator.
   if (UseODRIndicator(g)) {
@@ -398,13 +424,17 @@
 void __asan_unregister_globals(__asan_global *globals, uptr n) {
   if (!flags()->report_globals) return;
   BlockingMutexLock lock(&mu_for_globals);
-  for (uptr i = 0; i < n; i++) {
+  // Cache the offset within the globals list and walk backwards the globals
+  // array to have O(n) time for removing items from the globals list (where n
+  // is the globals list size). Without this cache it could become O(n^2).
+  ListOfGlobals *prev_list = nullptr;
+  for (uptr i = n; i-- > 0; ) {
     if (SANITIZER_WINDOWS && globals[i].beg == 0) {
       // Skip globals that look like padding from the MSVC incremental linker.
       // See comment in __asan_register_globals.
       continue;
     }
-    UnregisterGlobal(&globals[i]);
+    UnregisterGlobal(&globals[i], &prev_list);
   }
 
   // Unpoison the metadata.
Index: test/asan/TestCases/Posix/dlclose-globals.cc
===================================================================
--- /dev/null
+++ test/asan/TestCases/Posix/dlclose-globals.cc
@@ -0,0 +1,38 @@
+// RUN: %clangxx_asan -O0 -DSHARED_LIB %s -fPIC -shared -o %t-so.so
+// RUN: %clangxx_asan -O0 %s %libdl -o %t
+// RUN: %env_asan_opts=handle_segv=0 %run %t %t-so.so 2>&1 | FileCheck %s
+
+#include <dlfcn.h>
+#include <sanitizer/asan_interface.h>
+#include <stdio.h>
+
+#ifndef SHARED_LIB
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    printf("Usage: %s test.so\n", argv[0]);
+    return 1;
+  }
+  const char *libname = argv[1];
+  void *handle = dlopen(argv[1], RTLD_NOW | RTLD_LOCAL);
+  if (!handle) {
+    printf("dlopen failed: %s\n", dlerror());
+    return 2;
+  }
+  char *ver = (char *)dlsym(handle, "VERSION");
+  if (!ver) {
+    printf("dlsym(VERSION) failed: %s\n", dlerror());
+    return 3;
+  }
+
+  // CHECK: VERSION: dummy 1.0
+  printf("VERSION: %s\n", ver);
+  fflush(stdout);
+  dlclose(handle);
+
+  // CHECK: AddressSanitizer can not describe address in more detail (wild memory access suspected).
+  __asan_describe_address(0);
+  return 0;
+}
+#else  // SHARED_LIB
+extern "C" const char VERSION[] = "dummy 1.0";
+#endif // SHARED_LIB
Index: test/asan/TestCases/Windows/freelibrary-globals.cc
===================================================================
--- /dev/null
+++ test/asan/TestCases/Windows/freelibrary-globals.cc
@@ -0,0 +1,35 @@
+// RUN: %clang_cl_asan -LD -O0 -DSHARED_LIB %s -Fe%t.dll
+// RUN: %clang_cl_asan -O0 %s -Fe%te.exe
+// RUN: %env_asan_opts=handle_segv=0 %run %te.exe %t.dll 2>&1 | FileCheck %s
+
+#include <sanitizer/asan_interface.h>
+#include <stdio.h>
+#include <windows.h>
+
+#ifndef SHARED_LIB
+int main(int argc, char **argv) {
+  if (argc != 2) {
+    printf("Usage: %s test.dll\n", argv[0]);
+    return 1;
+  }
+  const char *libname = argv[1];
+  HMODULE handle = LoadLibrary(libname);
+  if (!handle)
+    return 2;
+
+  char *ver = (char *)GetProcAddress(handle, "VERSION");
+  if (!ver)
+    return 3;
+
+  // CHECK: VERSION: dummy 1.0
+  printf("VERSION: %s\n", ver);
+  fflush(stdout);
+  FreeLibrary(handle);
+
+  // CHECK: AddressSanitizer can not describe address in more detail (wild memory access suspected).
+  __asan_describe_address(0);
+  return 0;
+}
+#else  // SHARED_LIB
+extern "C" __declspec(dllexport) const char VERSION[] = "dummy 1.0";
+#endif // SHARED_LIB