diff --git a/mysql-test/main/func_date_add.result b/mysql-test/main/func_date_add.result
index a6201a3c23f..1c2d9ab5eb1 100644
--- a/mysql-test/main/func_date_add.result
+++ b/mysql-test/main/func_date_add.result
@@ -200,3 +200,34 @@ select 30 + (20010101 + interval 2 day), x from v1;
 20010133	20010133
 drop view v1;
 End of 10.2 tests
+#
+# Start of 10.5 tests
+#
+#
+# MDEV-30931 UBSAN: negation of -X cannot be represented in type 'long long int'; cast to an unsigned type to negate this value to itself in get_interval_value on SELECT
+#
+SELECT DATE_ADD('01-01-23',INTERVAL '9223372036854775808-02' WEEK);
+DATE_ADD('01-01-23',INTERVAL '9223372036854775808-02' WEEK)
+NULL
+Warnings:
+Warning	1292	Truncated incorrect INTEGER value: '9223372036854775808-02'
+Warning	1441	Datetime function: datetime field overflow
+SELECT DATE_ADD('01-01-23',INTERVAL -9223372036854775807 WEEK);
+DATE_ADD('01-01-23',INTERVAL -9223372036854775807 WEEK)
+NULL
+Warnings:
+Warning	1441	Datetime function: datetime field overflow
+SELECT DATE_ADD('01-01-23',INTERVAL -9223372036854775808 WEEK);
+DATE_ADD('01-01-23',INTERVAL -9223372036854775808 WEEK)
+NULL
+Warnings:
+Warning	1441	Datetime function: datetime field overflow
+SELECT DATE_ADD('01-01-23',INTERVAL -9223372036854775809 WEEK);
+DATE_ADD('01-01-23',INTERVAL -9223372036854775809 WEEK)
+NULL
+Warnings:
+Warning	1916	Got overflow when converting '-9223372036854775809' to INT. Value truncated
+Warning	1441	Datetime function: datetime field overflow
+#
+# End of 10.5 tests
+#
diff --git a/mysql-test/main/func_date_add.test b/mysql-test/main/func_date_add.test
index f9287b952d2..aa00fd144e2 100644
--- a/mysql-test/main/func_date_add.test
+++ b/mysql-test/main/func_date_add.test
@@ -169,3 +169,20 @@ select 30 + (20010101 + interval 2 day), x from v1;
 drop view v1;
 
 --echo End of 10.2 tests
+
+--echo #
+--echo # Start of 10.5 tests
+--echo #
+
+--echo #
+--echo # MDEV-30931 UBSAN: negation of -X cannot be represented in type 'long long int'; cast to an unsigned type to negate this value to itself in get_interval_value on SELECT
+--echo #
+
+SELECT DATE_ADD('01-01-23',INTERVAL '9223372036854775808-02' WEEK);
+SELECT DATE_ADD('01-01-23',INTERVAL -9223372036854775807 WEEK);
+SELECT DATE_ADD('01-01-23',INTERVAL -9223372036854775808 WEEK);
+SELECT DATE_ADD('01-01-23',INTERVAL -9223372036854775809 WEEK);
+
+--echo #
+--echo # End of 10.5 tests
+--echo #
diff --git a/sql/item_timefunc.cc b/sql/item_timefunc.cc
index 2f689acc54c..cd0e88544e0 100644
--- a/sql/item_timefunc.cc
+++ b/sql/item_timefunc.cc
@@ -1306,6 +1306,15 @@ my_decimal *Item_func_time_to_sec::decimal_op(my_decimal* buf)
 }
 
 
+static inline
+uint32 adjust_interval_field_uint32(ulonglong value, int32 multiplier)
+{
+  return value > ((ulonglong) (uint32) (UINT_MAX32)) / multiplier ?
+         (uint32) UINT_MAX32 :
+         (uint32) (value * multiplier);
+}
+
+
 /**
   Convert a string to a interval value.
 
@@ -1316,7 +1325,7 @@ bool get_interval_value(THD *thd, Item *args,
                         interval_type int_type, INTERVAL *interval)
 {
   ulonglong array[5];
-  longlong UNINIT_VAR(value);
+  ulonglong UNINIT_VAR(value);
   const char *UNINIT_VAR(str);
   size_t UNINIT_VAR(length);
   CHARSET_INFO *UNINIT_VAR(cs);
@@ -1343,14 +1352,17 @@ bool get_interval_value(THD *thd, Item *args,
   }
   else if ((int) int_type <= INTERVAL_MICROSECOND)
   {
-    value= args->val_int();
-    if (args->null_value)
-      return 1;
-    if (value < 0)
-    {
-      interval->neg=1;
-      value= -value;
-    }
+    /*
+      Let's use Longlong_hybrid_null to handle correctly:
+      - signed and unsigned values
+      - the corner case with LONGLONG_MIN
+        (avoid undefined behavior with its negation)
+    */
+    const Longlong_hybrid_null nr= args->to_longlong_hybrid_null();
+    if (nr.is_null())
+      return true;
+    value= nr.abs();
+    interval->neg= nr.neg() ? 1 : 0;
   }
   else
   {
@@ -1377,13 +1389,13 @@ bool get_interval_value(THD *thd, Item *args,
     interval->year= (ulong) value;
     break;
   case INTERVAL_QUARTER:
-    interval->month= (ulong)(value*3);
+    interval->month= adjust_interval_field_uint32(value, 3);
     break;
   case INTERVAL_MONTH:
     interval->month= (ulong) value;
     break;
   case INTERVAL_WEEK:
-    interval->day= (ulong)(value*7);
+    interval->day= adjust_interval_field_uint32(value, 7);
     break;
   case INTERVAL_DAY:
     interval->day= (ulong) value;
diff --git a/sql/sql_time.cc b/sql/sql_time.cc
index 12e4460ed25..90bf701fadc 100644
--- a/sql/sql_time.cc
+++ b/sql/sql_time.cc
@@ -930,7 +930,7 @@ void make_truncated_value_warning(THD *thd,
 bool date_add_interval(THD *thd, MYSQL_TIME *ltime, interval_type int_type,
                        const INTERVAL &interval, bool push_warn)
 {
-  long period, sign;
+  long sign;
 
   sign= (interval.neg == (bool)ltime->neg ? 1 : -1);
 
@@ -1001,13 +1001,17 @@ bool date_add_interval(THD *thd, MYSQL_TIME *ltime, interval_type int_type,
     break;
   }
   case INTERVAL_WEEK:
-    period= (calc_daynr(ltime->year,ltime->month,ltime->day) +
-             sign * (long) interval.day);
+  {
+    longlong period= calc_daynr(ltime->year, ltime->month, ltime->day) +
+                     (longlong) sign * (longlong) interval.day;
+    if (period < 0 || period > 0x7FFFFFFF)
+      goto invalid_date;
     /* Daynumber from year 0 to 9999-12-31 */
     if (get_date_from_daynr((long) period,&ltime->year,&ltime->month,
                             &ltime->day))
       goto invalid_date;
     break;
+  }
   case INTERVAL_YEAR:
     ltime->year+= sign * (long) interval.year;
     if ((ulong) ltime->year >= 10000L)
@@ -1019,8 +1023,9 @@ bool date_add_interval(THD *thd, MYSQL_TIME *ltime, interval_type int_type,
   case INTERVAL_YEAR_MONTH:
   case INTERVAL_QUARTER:
   case INTERVAL_MONTH:
-    period= (ltime->year*12 + sign * (long) interval.year*12 +
-	     ltime->month-1 + sign * (long) interval.month);
+  {
+    long period= (ltime->year*12 + sign * (long) interval.year*12 +
+	         ltime->month-1 + sign * (long) interval.month);
     if ((ulong) period >= 120000L)
       goto invalid_date;
     ltime->year= (uint) (period / 12);
@@ -1033,6 +1038,7 @@ bool date_add_interval(THD *thd, MYSQL_TIME *ltime, interval_type int_type,
 	ltime->day++;				// Leap-year
     }
     break;
+  }
   default:
     goto null_date;
   }
diff --git a/strings/my_strtoll10.c b/strings/my_strtoll10.c
index 8144be7a1da..74baef080eb 100644
--- a/strings/my_strtoll10.c
+++ b/strings/my_strtoll10.c
@@ -241,7 +241,7 @@ end4:
   *endptr= (char*) s;
   if (negative)
   {
-   if (li >= MAX_NEGATIVE_NUMBER)
+   if (li >= MAX_NEGATIVE_NUMBER) // Avoid undefined behavior
      goto overflow;
    return -((longlong) li);
   }