Index: lldb/source/Plugins/Process/Utility/DynamicRegisterInfo.cpp
===================================================================
--- lldb/source/Plugins/Process/Utility/DynamicRegisterInfo.cpp
+++ lldb/source/Plugins/Process/Utility/DynamicRegisterInfo.cpp
@@ -402,12 +402,22 @@
   assert(reg_info.name);
   uint32_t i;
   if (reg_info.value_regs) {
-    for (i = 0; reg_info.value_regs[i] != LLDB_INVALID_REGNUM; ++i)
-      m_value_regs_map[reg_num].push_back(reg_info.value_regs[i]);
+    reg_num_collection &regs = m_value_regs_map[reg_num];
+    for (i = 0;; ++i) {
+      regs.push_back(reg_info.value_regs[i]);
+      if (reg_info.value_regs[i] == LLDB_INVALID_REGNUM)
+        break;
+    }
+    reg_info.value_regs = regs.data();
   }
   if (reg_info.invalidate_regs) {
-    for (i = 0; reg_info.invalidate_regs[i] != LLDB_INVALID_REGNUM; ++i)
-      m_invalidate_regs_map[reg_num].push_back(reg_info.invalidate_regs[i]);
+    reg_num_collection &regs = m_invalidate_regs_map[reg_num];
+    for (i = 0;; ++i) {
+      regs.push_back(reg_info.invalidate_regs[i]);
+      if (reg_info.invalidate_regs[i] == LLDB_INVALID_REGNUM)
+        break;
+    }
+    reg_info.invalidate_regs = regs.data();
   }
   if (reg_info.dynamic_size_dwarf_expr_bytes) {
     for (i = 0; i < reg_info.dynamic_size_dwarf_len; ++i)
Index: lldb/unittests/Process/Utility/CMakeLists.txt
===================================================================
--- lldb/unittests/Process/Utility/CMakeLists.txt
+++ lldb/unittests/Process/Utility/CMakeLists.txt
@@ -15,9 +15,10 @@
   ${NETBSD_SOURCES})
 
 add_lldb_unittest(ProcessUtilityTests
-  RegisterContextTest.cpp
+  DynamicRegisterInfoTest.cpp
   LinuxProcMapsTest.cpp
   MemoryTagManagerAArch64MTETest.cpp
+  RegisterContextTest.cpp
   ${PLATFORM_SOURCES}
 
   LINK_LIBS
Index: lldb/unittests/Process/Utility/DynamicRegisterInfoTest.cpp
===================================================================
--- /dev/null
+++ lldb/unittests/Process/Utility/DynamicRegisterInfoTest.cpp
@@ -0,0 +1,44 @@
+//===-- DynamicRegisterInfoTest.cpp ---------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+#include "Plugins/Process/Utility/DynamicRegisterInfo.h"
+
+using namespace lldb_private;
+
+TEST(DynamicRegisterInfoTest, regs_copy) {
+  DynamicRegisterInfo info;
+
+  uint32_t value_regs[] = {1, LLDB_INVALID_REGNUM};
+  uint32_t invalidate_regs[] = {2, 3, LLDB_INVALID_REGNUM};
+
+  struct RegisterInfo new_reg {
+    "foo", nullptr, 8, 0, lldb::eEncodingUint, lldb::eFormatUnsigned,
+    {LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM, LLDB_INVALID_REGNUM, 0, 0},
+    value_regs, invalidate_regs, nullptr, 0
+  };
+
+  ConstString group{"group"};
+  info.AddRegister(new_reg, group);
+
+  // AddRegister() should have created a copy of these two arrays,
+  // so local changes should not affect returned RegisterInfo.
+  value_regs[0] = 4;
+  invalidate_regs[0] = 5;
+  invalidate_regs[1] = 6;
+
+  const RegisterInfo *added_reg = info.GetRegisterInfoAtIndex(0);
+  ASSERT_NE(added_reg, nullptr);
+  ASSERT_EQ(added_reg->value_regs[0], 1U);
+  ASSERT_EQ(added_reg->value_regs[1], LLDB_INVALID_REGNUM);
+  ASSERT_EQ(added_reg->invalidate_regs[0], 2U);
+  ASSERT_EQ(added_reg->invalidate_regs[1], 3U);
+  ASSERT_EQ(added_reg->invalidate_regs[2], LLDB_INVALID_REGNUM);
+}