diff --git a/dlls/ntdll/sync.c b/dlls/ntdll/sync.c
index 8e406ceaebe..bb462f211e7 100644
--- a/dlls/ntdll/sync.c
+++ b/dlls/ntdll/sync.c
@@ -114,6 +114,8 @@ NTSTATUS alloc_object_attributes( const OBJECT_ATTRIBUTES *attr, struct object_a
     }
     else if (attr->RootDirectory) return STATUS_OBJECT_NAME_INVALID;
 
+    len = (len + 3) & ~3;  /* DWORD-align the entire structure */
+
     *ret = RtlAllocateHeap( GetProcessHeap(), HEAP_ZERO_MEMORY, len );
     if (!*ret) return STATUS_NO_MEMORY;
 
diff --git a/include/wine/server_protocol.h b/include/wine/server_protocol.h
index 0b61b915f0b..24eb95be26d 100644
--- a/include/wine/server_protocol.h
+++ b/include/wine/server_protocol.h
@@ -6535,6 +6535,6 @@ union generic_reply
     struct terminate_job_reply terminate_job_reply;
 };
 
-#define SERVER_PROTOCOL_VERSION 559
+#define SERVER_PROTOCOL_VERSION 560
 
 #endif /* __WINE_WINE_SERVER_PROTOCOL_H */
diff --git a/server/request.c b/server/request.c
index 77f4f71d8aa..2dd84fbbb3c 100644
--- a/server/request.c
+++ b/server/request.c
@@ -214,16 +214,15 @@ const struct object_attributes *get_req_object_attributes( const struct security
 /* return a pointer to the request data following an object attributes structure */
 const void *get_req_data_after_objattr( const struct object_attributes *attr, data_size_t *len )
 {
-    const void *ptr;
+    data_size_t size = (sizeof(*attr) + (attr->sd_len & ~1) + (attr->name_len & ~1) + 3) & ~3;
 
-    if (attr == &empty_attributes)
+    if (attr == &empty_attributes || size >= get_req_data_size())
     {
         *len = 0;
         return NULL;
     }
-    ptr = (const WCHAR *)(attr + 1) + attr->sd_len / sizeof(WCHAR) + attr->name_len / sizeof(WCHAR);
-    *len = get_req_data_size() - ((const char *)ptr - (const char *)get_req_data());
-    return ptr;
+    *len = get_req_data_size() - size;
+    return (const char *)get_req_data() + size;
 }
 
 /* write the remaining part of the reply */
diff --git a/server/trace.c b/server/trace.c
index 3c0d59257eb..1a28cac13e5 100644
--- a/server/trace.c
+++ b/server/trace.c
@@ -1119,8 +1119,7 @@ static void dump_varargs_object_attributes( const char *prefix, data_size_t size
         fprintf( stderr, ",name=L\"" );
         dump_strW( str, objattr->name_len / sizeof(WCHAR), stderr, "\"\"" );
         fputc( '\"', stderr );
-        remove_data( ((sizeof(*objattr) + objattr->sd_len) / sizeof(WCHAR)) * sizeof(WCHAR) +
-                     (objattr->name_len / sizeof(WCHAR)) * sizeof(WCHAR) );
+        remove_data( (sizeof(*objattr) + (objattr->sd_len & ~1) + (objattr->name_len & ~1) + 3) & ~3 );
     }
     fputc( '}', stderr );
 }