diff a/storage/innobase/buf/buf0flu.cc b/storage/innobase/buf/buf0flu.cc

--- a/storage/innobase/buf/buf0flu.cc

+++ b/storage/innobase/buf/buf0flu.cc

@@ -1246,16 +1246,14 @@ static void buf_flush_LRU_list_batch(ulint max, bool evict,

     ut_ad(state >= buf_page_t::FREED);

     ut_ad(bpage->in_LRU_list);

-    switch (bpage->oldest_modification()) {

-    case 0:

+    if (!bpage->oldest_modification())

+    {

     evict:

       if (state != buf_page_t::FREED &&

           (state >= buf_page_t::READ_FIX || (~buf_page_t::LRU_MASK & state)))

         continue;

       buf_LRU_free_page(bpage, true);

       ++n->evicted;

-      /* fall through */

-    case 1:

       if (UNIV_LIKELY(scanned & 31))

         continue;

       mysql_mutex_unlock(&buf_pool.mutex);

@@ -1271,7 +1269,11 @@ static void buf_flush_LRU_list_batch(ulint max, bool evict,

       switch (bpage->oldest_modification()) {

       case 1:

         mysql_mutex_lock(&buf_pool.flush_list_mutex);

-        buf_pool.delete_from_flush_list(bpage);

+        if (ut_d(lsn_t lsn=) bpage->oldest_modification())

+        {

+          ut_ad(lsn == 1); /* It must be clean while we hold bpage->lock */

+          buf_pool.delete_from_flush_list(bpage);

+        }

         mysql_mutex_unlock(&buf_pool.flush_list_mutex);

         /* fall through */

       case 0:

InnoDB: Failing assertion: list.count > 0