diff --git a/build/libraries_sysmenu/dht/common/src/dht.c b/build/libraries_sysmenu/dht/common/src/dht.c
index 6da8cd33..9affd8db 100644
--- a/build/libraries_sysmenu/dht/common/src/dht.c
+++ b/build/libraries_sysmenu/dht/common/src/dht.c
@@ -159,7 +159,7 @@ static BOOL DHT_CheckDatabase(const DHTFile* pDHT)
     return TRUE;
 }
 
-BOOL DHT_PrepareDatabase(DHTFile* pDHT, FSFile* fp)
+BOOL DHT_PrepareDatabase(DHTFile* pDHT, FSFile* fp, s32 maxLength)
 {
     s32 result;
     s32 length;
@@ -177,12 +177,18 @@ BOOL DHT_PrepareDatabase(DHTFile* pDHT, FSFile* fp)
         }
         // データベース読み込み
         PROFILE_COUNT();
-        length = (s32)DHT_GetDatabaseLength(pDHT) - (s32)sizeof(DHTHeader); // ヘッダを除く
-        if ( length < 0 )
+        length = (s32)DHT_GetDatabaseLength(pDHT);
+        if ( length < sizeof(DHTHeader) )
         {
             OS_TPrintf("Invalid DHT header.\n");
             return FALSE;
         }
+        if ( length > maxLength )
+        {
+            OS_TPrintf("Too large size specified in the header.\n");
+            return FALSE;
+        }
+        length -= (s32)sizeof(DHTHeader);   // ヘッダを除く
         result = FS_ReadFile(fp, pDHT->database, length);
         if ( result != length )
         {
@@ -265,7 +271,7 @@ static BOOL DHT_CheckDatabaseEx(const DHTFileEx* pDHT)
     return TRUE;
 }
 
-BOOL DHT_PrepareDatabaseEx(DHTFileEx* pDHT, FSFile* fp)
+BOOL DHT_PrepareDatabaseEx(DHTFileEx* pDHT, FSFile* fp, s32 maxLength)
 {
     s32 result;
     s32 length;
@@ -283,12 +289,18 @@ BOOL DHT_PrepareDatabaseEx(DHTFileEx* pDHT, FSFile* fp)
         }
         // 拡張データベース読み込み
         PROFILE_COUNT();
-        length = (s32)DHT_GetDatabaseExLength(pDHT) - (s32)sizeof(DHTHeader); // ヘッダを除く
-        if ( length < 0 )
+        length = (s32)DHT_GetDatabaseExLength(pDHT);
+        if ( length < sizeof(DHTHeader) )
         {
             OS_TPrintf("Invalid DHT header. [EX]\n");
             return FALSE;
         }
+        if ( length > maxLength )
+        {
+            OS_TPrintf("Too large size specified in the header.\n");
+            return FALSE;
+        }
+        length -= (s32)sizeof(DHTHeader); // ヘッダを除く
         result = FS_ReadFile(fp, pDHT->database, length);
         if ( result != length )
         {
@@ -371,7 +383,7 @@ static BOOL DHT_CheckDatabaseAdHoc(const DHTFileAdHoc* pDHT)
     return TRUE;
 }
 
-BOOL DHT_PrepareDatabaseAdHoc(DHTFileAdHoc* pDHT, FSFile* fp)
+BOOL DHT_PrepareDatabaseAdHoc(DHTFileAdHoc* pDHT, FSFile* fp, s32 maxLength)
 {
     s32 result;
     s32 length;
@@ -389,12 +401,18 @@ BOOL DHT_PrepareDatabaseAdHoc(DHTFileAdHoc* pDHT, FSFile* fp)
         }
         // 拡張データベース読み込み
         PROFILE_COUNT();
-        length = (s32)DHT_GetDatabaseAdHocLength(pDHT) - (s32)sizeof(DHTHeader); // ヘッダを除く
-        if ( length < 0 )
+        length = (s32)DHT_GetDatabaseAdHocLength(pDHT);
+        if ( length < sizeof(DHTHeader) )
         {
             OS_TPrintf("Invalid DHT header. [AdHoc]\n");
             return FALSE;
         }
+        if ( length < maxLength )
+        {
+            OS_TPrintf("Too large size specified in the header.\n");
+            return FALSE;
+        }
+        length -=  (s32)sizeof(DHTHeader); // ヘッダを除く
         result = FS_ReadFile(fp, pDHT->database, length);
         if ( result != length )
         {
diff --git a/build/libraries_sysmenu/sysmenu/ARM9/src/title.c b/build/libraries_sysmenu/sysmenu/ARM9/src/title.c
index fb0201b8..bbb6fe0c 100644
--- a/build/libraries_sysmenu/sysmenu/ARM9/src/title.c
+++ b/build/libraries_sysmenu/sysmenu/ARM9/src/title.c
@@ -284,57 +284,28 @@ static BOOL PrepareDHTDatabase(void)
     }
     // 基本データベース
     s_dht.dht = s_dht.buffer;
-    if ( sizeof(DHTHeader) != FS_ReadFile(&file, &s_dht.dht->header, sizeof(DHTHeader)) )
+    if ( !DHT_PrepareDatabase(s_dht.dht, &file, length) )
     {
-        OS_TPrintf("PrepareDHTDatabase failed: cannot read DHTHeader for phase 1/2.\n" );
+        OS_TPrintf("PrepareDHTDatabase failed: cannot read the list for phase 1/2.\n" );
         if(!s_b_dev) {
-           ERRORLOG_Printf( "WHITELIST_INITDB_FAILED (sub info): cannot read DHTHeader for phase 1/2.\n" );
+           ERRORLOG_Printf( "WHITELIST_INITDB_FAILED (sub info): cannot read the list for phase 1/2.\n" );
         }
         SYSM_Free( s_dht.buffer );
         s_dht.buffer = NULL;
         FS_CloseFile(&file);
         return FALSE; // cannot read the file
     }
-    length = (int)DHT_GetDatabaseLength(s_dht.dht) - (int)sizeof(DHTHeader);
-    if ( length < 0 || length != FS_ReadFile(&file, &s_dht.dht->database, length) )
-    {
-        OS_TPrintf("PrepareDHTDatabase failed: cannot read DHTDatabase for phase 1/2.\n" );
-        if(!s_b_dev) {
-           ERRORLOG_Printf( "WHITELIST_INITDB_FAILED (sub info): cannot read DHTDatabase for phase 1/2.\n" );
-        }
-        s_dht.dht = NULL;
-        SYSM_Free( s_dht.buffer );
-        s_dht.buffer = NULL;
-        FS_CloseFile(&file);
-        return FALSE; // cannot read the file
-    }
+    length -= DHT_GetDatabaseLength(s_dht.dht);
     // 拡張データベース
     s_dht.dhtex = (void*)((u32)s_dht.buffer + DHT_GetDatabaseLength(s_dht.dht));
-    if ( sizeof(DHTHeader) != FS_ReadFile(&file, &s_dht.dhtex->header, sizeof(DHTHeader)) )
+    if ( !DHT_PrepareDatabaseEx(s_dht.dhtex, &file, length) )
     {
         s_dht.dhtex = NULL;
-        OS_TPrintf("PrepareDHTDatabase failed: cannot read DHTHeader for phase 3.\n" );
+        OS_TPrintf("PrepareDHTDatabase failed: cannot read the list for phase 3.\n" );
         FS_CloseFile(&file);
 #ifndef SYSM_IGNORE_DHT_EX_NOT_FOUND
         if(!s_b_dev) {
-           ERRORLOG_Printf( "WHITELIST_INITDB_FAILED (sub info): cannot read DHTHeader for phase 3.\n" );
-        }
-        SYSM_Free( s_dht.buffer );
-        s_dht.buffer = NULL;
-        return FALSE; // cannot read the file
-#else
-        return TRUE;
-#endif
-    }
-    length = (int)DHT_GetDatabaseExLength(s_dht.dhtex) - (int)sizeof(DHTHeader);
-    if ( length < 0 || length != FS_ReadFile(&file, &s_dht.dhtex->database, length) )
-    {
-        s_dht.dhtex = NULL;
-        OS_TPrintf("PrepareDHTDatabase failed: cannot read DHTDatabaseEx for phase 3.\n" );
-        FS_CloseFile(&file);
-#ifndef SYSM_IGNORE_DHT_EX_NOT_FOUND
-        if(!s_b_dev) {
-           ERRORLOG_Printf( "WHITELIST_INITDB_FAILED (sub info): cannot read DHTDatabaseEx for phase 3.\n" );
+           ERRORLOG_Printf( "WHITELIST_INITDB_FAILED (sub info): cannot read the list for phase 3.\n" );
         }
         SYSM_Free( s_dht.buffer );
         s_dht.buffer = NULL;
@@ -343,33 +314,22 @@ static BOOL PrepareDHTDatabase(void)
         return TRUE;
 #endif
     }
+    length -= DHT_GetDatabaseExLength(s_dht.dhtex);
     // 個別対応データベース
     s_dht.dhtah = (void*)((u32)s_dht.buffer + DHT_GetDatabaseLength(s_dht.dht) + DHT_GetDatabaseExLength(s_dht.dhtex));
-    if ( sizeof(DHTHeader) != FS_ReadFile(&file, &s_dht.dhtah->header, sizeof(DHTHeader)) )
+    if ( !DHT_PrepareDatabaseAdHoc(s_dht.dhtah, &file, length) )
     {
         s_dht.dhtah = NULL;
-        OS_TPrintf("PrepareDHTDatabase failed: cannot read DHTHeader for phase 4.\n" );
+        OS_TPrintf("PrepareDHTDatabase failed: cannot read the list for phase 4.\n" );
         FS_CloseFile(&file);
         if(!s_b_dev) {
-           ERRORLOG_Printf( "WHITELIST_INITDB_FAILED (sub info): cannot read DHTHeader for phase 4.\n" );
-        }
-        SYSM_Free( s_dht.buffer );
-        s_dht.buffer = NULL;
-        return FALSE; // phase 3が読めてphase4が読めないことはあり得ない
-    }
-    length = (int)DHT_GetDatabaseAdHocLength(s_dht.dhtah) - (int)sizeof(DHTHeader);
-    if ( length < 0 || length != FS_ReadFile(&file, &s_dht.dhtah->database, length) )
-    {
-        s_dht.dhtah = NULL;
-        OS_TPrintf("PrepareDHTDatabase failed: cannot read DHTDatabaseAdHoc for phase 4.\n" );
-        FS_CloseFile(&file);
-        if(!s_b_dev) {
-           ERRORLOG_Printf( "WHITELIST_INITDB_FAILED (sub info): cannot read DHTDatabaseAdHoc for phase 4.\n" );
+           ERRORLOG_Printf( "WHITELIST_INITDB_FAILED (sub info): cannot read the list for phase 4.\n" );
         }
         SYSM_Free( s_dht.buffer );
         s_dht.buffer = NULL;
         return FALSE; // phase 3が読めてphase4が読めないことはあり得ない
     }
+    //length -= DHT_GetDatabaseAdHocLength(s_dht.dhtah);    // パディング部分が残る？
     FS_CloseFile(&file);
     return TRUE;
 }
diff --git a/include/sysmenu/dht/dht.h b/include/sysmenu/dht/dht.h
index 9f14f7b9..b0422568 100644
--- a/include/sysmenu/dht/dht.h
+++ b/include/sysmenu/dht/dht.h
@@ -137,10 +137,11 @@ u32 DHT_GetDatabaseAdHocLength(const DHTFileAdHoc* pDHT);
   Arguments:    pDHT        データベースの格納先
                 fp          ファイル構造体へのポインタ
                             DHTHeaderの先頭までシーク済みである必要がある
+                maxLength   読み込みサイズの上限(ヘッダ込み)
 
   Returns:      成功すればTRUE
  *---------------------------------------------------------------------------*/
-BOOL DHT_PrepareDatabase(DHTFile* pDHT, FSFile* fp);
+BOOL DHT_PrepareDatabase(DHTFile* pDHT, FSFile* fp, s32 maxLength);
 
 /*---------------------------------------------------------------------------*
   Name:         DHT_PrepareDatabaseEx
@@ -150,10 +151,11 @@ BOOL DHT_PrepareDatabase(DHTFile* pDHT, FSFile* fp);
   Arguments:    pDHT        拡張データベースの格納先
                 fp          ファイル構造体へのポインタ
                             DHTHeaderの先頭までシーク済みである必要がある
+                maxLength   読み込みサイズの上限(ヘッダ込み)
 
   Returns:      成功すればTRUE
  *---------------------------------------------------------------------------*/
-BOOL DHT_PrepareDatabaseEx(DHTFileEx* pDHT, FSFile* fp);
+BOOL DHT_PrepareDatabaseEx(DHTFileEx* pDHT, FSFile* fp, s32 maxLength);
 
 /*---------------------------------------------------------------------------*
   Name:         DHT_PrepareDatabaseAdHoc
@@ -163,10 +165,11 @@ BOOL DHT_PrepareDatabaseEx(DHTFileEx* pDHT, FSFile* fp);
   Arguments:    pDHT        個別対応データベースの格納先
                 fp          ファイル構造体へのポインタ
                             DHTHeaderの先頭までシーク済みである必要がある
+                maxLength   読み込みサイズの上限(ヘッダ込み)
 
   Returns:      成功すればTRUE
  *---------------------------------------------------------------------------*/
-BOOL DHT_PrepareDatabaseAdHoc(DHTFileAdHoc* pDHT, FSFile* fp);
+BOOL DHT_PrepareDatabaseAdHoc(DHTFileAdHoc* pDHT, FSFile* fp, s32 maxLength);
 
 /*---------------------------------------------------------------------------*
   Name:         DHT_GetDatabase