diff --git a/mysql-test/r/order_by.result b/mysql-test/r/order_by.result
index d35012e0de5..ffb37c9309f 100644
--- a/mysql-test/r/order_by.result
+++ b/mysql-test/r/order_by.result
@@ -3302,3 +3302,57 @@ a	b	c
 SET @@sort_buffer_size= @save_sort_buffer_size;
 SET @@max_sort_length= @save_max_sort_length;
 DROP TABLE t1;
+#
+# MDEV-22390: Assertion `m_next_rec_ptr >= m_rawmem' failed in Filesort_buffer::spaceleft |
+# SIGSEGV in __memmove_avx_unaligned_erms from my_b_write (on optimized)
+#
+SET @save_max_sort_length= @@max_sort_length;
+SET @save_sort_buffer_size= @@sort_buffer_size;
+SET @save_max_length_for_sort_data= @@max_length_for_sort_data;
+SET max_sort_length=8;
+SET sort_buffer_size=1024;
+SET max_length_for_sort_data=7000;
+CREATE TABLE t1(a VARCHAR(64), b VARCHAR(2048))DEFAULT CHARSET=utf8;
+INSERT INTO t1 SELECT seq,seq from seq_1_to_100;
+ANALYZE FORMAT=JSON SELECT * FROM t1 ORDER BY a LIMIT 5;
+ANALYZE
+{
+  "query_block": {
+    "select_id": 1,
+    "r_loops": 1,
+    "r_total_time_ms": "REPLACED",
+    "read_sorted_file": {
+      "r_rows": 5,
+      "filesort": {
+        "r_loops": 1,
+        "r_total_time_ms": "REPLACED",
+        "r_limit": 5,
+        "r_used_priority_queue": false,
+        "r_output_rows": 35,
+        "r_sort_passes": 1,
+        "r_buffer_size": "REPLACED",
+        "table": {
+          "table_name": "t1",
+          "access_type": "ALL",
+          "r_loops": 1,
+          "rows": 100,
+          "r_rows": 100,
+          "r_total_time_ms": "REPLACED",
+          "filtered": 100,
+          "r_filtered": 100
+        }
+      }
+    }
+  }
+}
+SELECT * FROM t1 ORDER BY a LIMIT 5;
+a	b
+1	1
+10	10
+100	100
+11	11
+12	12
+SET max_sort_length= @save_max_sort_length;
+SET sort_buffer_size= @save_sort_buffer_size;
+SET max_length_for_sort_data= @save_max_length_for_sort_data;
+DROP TABLE t1;
diff --git a/mysql-test/t/order_by.test b/mysql-test/t/order_by.test
index 2fbacb10b68..3a30e0b6c76 100644
--- a/mysql-test/t/order_by.test
+++ b/mysql-test/t/order_by.test
@@ -2174,3 +2174,25 @@ SELECT * FROM t1 ORDER BY a,b;
 SET @@sort_buffer_size= @save_sort_buffer_size;
 SET @@max_sort_length= @save_max_sort_length;
 DROP TABLE t1;
+
+--echo #
+--echo # MDEV-22390: Assertion `m_next_rec_ptr >= m_rawmem' failed in Filesort_buffer::spaceleft |
+--echo # SIGSEGV in __memmove_avx_unaligned_erms from my_b_write (on optimized)
+--echo #
+
+SET @save_max_sort_length= @@max_sort_length;
+SET @save_sort_buffer_size= @@sort_buffer_size;
+SET @save_max_length_for_sort_data= @@max_length_for_sort_data;
+SET max_sort_length=8;
+SET sort_buffer_size=1024;
+# needed to make sure we use addon fields
+SET max_length_for_sort_data=7000;
+CREATE TABLE t1(a VARCHAR(64), b VARCHAR(2048))DEFAULT CHARSET=utf8;
+INSERT INTO t1 SELECT seq,seq from seq_1_to_100;
+--source include/analyze-format.inc
+ANALYZE FORMAT=JSON SELECT * FROM t1 ORDER BY a LIMIT 5;
+SELECT * FROM t1 ORDER BY a LIMIT 5;
+SET max_sort_length= @save_max_sort_length;
+SET sort_buffer_size= @save_sort_buffer_size;
+SET max_length_for_sort_data= @save_max_length_for_sort_data;
+DROP TABLE t1;
diff --git a/sql/filesort.cc b/sql/filesort.cc
index bb3e73343ad..90edd39b1da 100644
--- a/sql/filesort.cc
+++ b/sql/filesort.cc
@@ -256,7 +256,8 @@ ha_rows filesort(THD *thd, TABLE *table, SORT_FIELD *sortorder, uint s_length,
     while (memory_available >= min_sort_memory)
     {
       ulonglong keys= memory_available / (param.rec_length + sizeof(char*));
-      param.max_keys_per_buffer= (uint) MY_MIN(num_rows, keys);
+      param.max_keys_per_buffer= MY_MAX(MERGEBUFF2,
+                                        (uint) MY_MIN(num_rows, keys));
       if (table_sort.get_sort_keys())
       {
         // If we have already allocated a buffer, it better have same size!
diff --git a/sql/filesort_utils.cc b/sql/filesort_utils.cc
index f1a164dd9fe..287edddf619 100644
--- a/sql/filesort_utils.cc
+++ b/sql/filesort_utils.cc
@@ -97,7 +97,6 @@ uchar **Filesort_buffer::alloc_sort_buffer(uint num_records, uint record_length)
   if (m_idx_array.is_null())
   {
     sort_buff_sz= ((size_t)num_records) * (record_length + sizeof(uchar*));
-    set_if_bigger(sort_buff_sz, record_length * MERGEBUFF2); 
     uchar **sort_keys=
       (uchar**) my_malloc(sort_buff_sz, MYF(MY_THREAD_SPECIFIC));
     m_idx_array= Idx_array(sort_keys, num_records);