Commit bebcb221 authored by unknown's avatar unknown

Bug #30587: mysql crashes when trying to group by TIME div NUMBER

When calculating the result length of an integer DIV function 
the number of decimals was used without checking the result type
first. Thus an uninitialized number of decimals was used for some 
types. This caused an excessive amount of memory to be allocated 
for the field's buffer and crashed the server.

 
Fixed by using the number of decimals only for data types that 
can have decimals and thus have valid decimals number.


mysql-test/r/func_math.result:
  Bug #30587: test case
mysql-test/t/func_math.test:
  Bug #30587: test case
sql/item_func.cc:
  Bug #30587: Don't use decimals on a type that doesn't have them.
parent ffdc5b93
......@@ -322,4 +322,50 @@ mod(5, cast(-2 as unsigned)) mod(5, 18446744073709551614) mod(5, -2)
select pow(cast(-2 as unsigned), 5), pow(18446744073709551614, 5), pow(-2, 5);
pow(cast(-2 as unsigned), 5) pow(18446744073709551614, 5) pow(-2, 5)
2.1359870359209e+96 2.1359870359209e+96 -32
CREATE TABLE t1 (a timestamp, b varchar(20), c bit(1));
INSERT INTO t1 VALUES('1998-09-23', 'str1', 1), ('2003-03-25', 'str2', 0);
SELECT a DIV 900 y FROM t1 GROUP BY y;
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def y y 8 19 11 Y 32800 0 63
y
22201025555
22255916666
SELECT DISTINCT a DIV 900 y FROM t1;
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def y y 8 19 11 Y 32800 0 63
y
22201025555
22255916666
SELECT b DIV 900 y FROM t1 GROUP BY y;
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def y y 8 20 1 Y 32768 0 63
y
0
SELECT c DIV 900 y FROM t1 GROUP BY y;
Catalog Database Table Table_alias Column Column_alias Type Length Max length Is_null Flags Decimals Charsetnr
def y y 3 1 1 Y 32800 0 63
y
0
DROP TABLE t1;
CREATE TABLE t1(a LONGBLOB);
INSERT INTO t1 VALUES('1'),('2'),('3');
SELECT DISTINCT (a DIV 254576881) FROM t1;
(a DIV 254576881)
0
SELECT (a DIV 254576881) FROM t1 UNION ALL
SELECT (a DIV 254576881) FROM t1;
(a DIV 254576881)
0
0
0
0
0
0
DROP TABLE t1;
CREATE TABLE t1(a SET('a','b','c'));
INSERT INTO t1 VALUES ('a');
SELECT a DIV 2 FROM t1 UNION SELECT a DIV 2 FROM t1;
a DIV 2
0
DROP TABLE t1;
End of 5.0 tests
......@@ -205,4 +205,31 @@ select mod(cast(-2 as unsigned), 3), mod(18446744073709551614, 3), mod(-2, 3);
select mod(5, cast(-2 as unsigned)), mod(5, 18446744073709551614), mod(5, -2);
select pow(cast(-2 as unsigned), 5), pow(18446744073709551614, 5), pow(-2, 5);
#
# Bug #30587: mysql crashes when trying to group by TIME div NUMBER
#
CREATE TABLE t1 (a timestamp, b varchar(20), c bit(1));
INSERT INTO t1 VALUES('1998-09-23', 'str1', 1), ('2003-03-25', 'str2', 0);
--enable_metadata
SELECT a DIV 900 y FROM t1 GROUP BY y;
SELECT DISTINCT a DIV 900 y FROM t1;
SELECT b DIV 900 y FROM t1 GROUP BY y;
SELECT c DIV 900 y FROM t1 GROUP BY y;
--disable_metadata
DROP TABLE t1;
CREATE TABLE t1(a LONGBLOB);
INSERT INTO t1 VALUES('1'),('2'),('3');
SELECT DISTINCT (a DIV 254576881) FROM t1;
SELECT (a DIV 254576881) FROM t1 UNION ALL
SELECT (a DIV 254576881) FROM t1;
DROP TABLE t1;
CREATE TABLE t1(a SET('a','b','c'));
INSERT INTO t1 VALUES ('a');
SELECT a DIV 2 FROM t1 UNION SELECT a DIV 2 FROM t1;
DROP TABLE t1;
--echo End of 5.0 tests
......@@ -1380,7 +1380,11 @@ longlong Item_func_int_div::val_int()
void Item_func_int_div::fix_length_and_dec()
{
max_length=args[0]->max_length - args[0]->decimals;
Item_result argtype= args[0]->result_type();
/* use precision ony for the data type it is applicable for and valid */
max_length=args[0]->max_length -
(argtype == DECIMAL_RESULT || argtype == INT_RESULT ?
args[0]->decimals : 0);
maybe_null=1;
unsigned_flag=args[0]->unsigned_flag | args[1]->unsigned_flag;
}
......
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