Guard against overflow in interval_mul() and interval_div().

Commits 146604ec43 and a898b409f6 added overflow checks to
interval_mul(), but not to interval_div(), which contains almost
identical code, and so is susceptible to the same kinds of
overflows. In addition, those checks did not catch all possible
overflow conditions.

Add additional checks to the "cascade down" code in interval_mul(),
and copy all the overflow checks over to the corresponding code in
interval_div(), so that they both generate "interval out of range"
errors, rather than returning bogus results.

Given that these errors are relatively easy to hit, back-patch to all
supported branches.

Per bug #18200 from Alexander Lakhin, and subsequent investigation.

Discussion: https://postgr.es/m/18200-5ea288c7b2d504b1%40postgresql.org

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index fbe3c29ee10eb360eb748ad1f28db5ee6a31e5ef..a18e1d2b29824a5577bf8b46127a52e5e195c231 100644 (file)
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -3190,19 +3190,13 @@ interval_mul(PG_FUNCTION_ARGS)
    result = (Interval *) palloc(sizeof(Interval));
 
    result_double = span->month * factor;
-   if (isnan(result_double) ||
-       result_double > INT_MAX || result_double < INT_MIN)
-       ereport(ERROR,
-               (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-                errmsg("interval out of range")));
+   if (isnan(result_double) || !FLOAT8_FITS_IN_INT32(result_double))
+       goto out_of_range;
    result->month = (int32) result_double;
 
    result_double = span->day * factor;
-   if (isnan(result_double) ||
-       result_double > INT_MAX || result_double < INT_MIN)
-       ereport(ERROR,
-               (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-                errmsg("interval out of range")));
+   if (isnan(result_double) || !FLOAT8_FITS_IN_INT32(result_double))
+       goto out_of_range;
    result->day = (int32) result_double;
 
    /*
@@ -3236,20 +3230,30 @@ interval_mul(PG_FUNCTION_ARGS)
     */
    if (Abs(sec_remainder) >= SECS_PER_DAY)
    {
-       result->day += (int) (sec_remainder / SECS_PER_DAY);
+       if (pg_add_s32_overflow(result->day,
+                               (int) (sec_remainder / SECS_PER_DAY),
+                               &result->day))
+           goto out_of_range;
        sec_remainder -= (int) (sec_remainder / SECS_PER_DAY) * SECS_PER_DAY;
    }
 
    /* cascade units down */
-   result->day += (int32) month_remainder_days;
+   if (pg_add_s32_overflow(result->day, (int32) month_remainder_days,
+                           &result->day))
+       goto out_of_range;
    result_double = rint(span->time * factor + sec_remainder * USECS_PER_SEC);
    if (isnan(result_double) || !FLOAT8_FITS_IN_INT64(result_double))
-       ereport(ERROR,
-               (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
-                errmsg("interval out of range")));
+       goto out_of_range;
    result->time = (int64) result_double;
 
    PG_RETURN_INTERVAL_P(result);
+
+out_of_range:
+   ereport(ERROR,
+           errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+           errmsg("interval out of range"));
+
+   PG_RETURN_NULL();           /* keep compiler quiet */
 }
 
 Datum
@@ -3268,7 +3272,8 @@ interval_div(PG_FUNCTION_ARGS)
    Interval   *span = PG_GETARG_INTERVAL_P(0);
    float8      factor = PG_GETARG_FLOAT8(1);
    double      month_remainder_days,
-               sec_remainder;
+               sec_remainder,
+               result_double;
    int32       orig_month = span->month,
                orig_day = span->day;
    Interval   *result;
@@ -3280,8 +3285,15 @@ interval_div(PG_FUNCTION_ARGS)
                (errcode(ERRCODE_DIVISION_BY_ZERO),
                 errmsg("division by zero")));
 
-   result->month = (int32) (span->month / factor);
-   result->day = (int32) (span->day / factor);
+   result_double = span->month / factor;
+   if (isnan(result_double) || !FLOAT8_FITS_IN_INT32(result_double))
+       goto out_of_range;
+   result->month = (int32) result_double;
+
+   result_double = span->day / factor;
+   if (isnan(result_double) || !FLOAT8_FITS_IN_INT32(result_double))
+       goto out_of_range;
+   result->day = (int32) result_double;
 
    /*
     * Fractional months full days into days.  See comment in interval_mul().
@@ -3293,15 +3305,30 @@ interval_div(PG_FUNCTION_ARGS)
    sec_remainder = TSROUND(sec_remainder);
    if (Abs(sec_remainder) >= SECS_PER_DAY)
    {
-       result->day += (int) (sec_remainder / SECS_PER_DAY);
+       if (pg_add_s32_overflow(result->day,
+                               (int) (sec_remainder / SECS_PER_DAY),
+                               &result->day))
+           goto out_of_range;
        sec_remainder -= (int) (sec_remainder / SECS_PER_DAY) * SECS_PER_DAY;
    }
 
    /* cascade units down */
-   result->day += (int32) month_remainder_days;
-   result->time = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
+   if (pg_add_s32_overflow(result->day, (int32) month_remainder_days,
+                           &result->day))
+       goto out_of_range;
+   result_double = rint(span->time / factor + sec_remainder * USECS_PER_SEC);
+   if (isnan(result_double) || !FLOAT8_FITS_IN_INT64(result_double))
+       goto out_of_range;
+   result->time = (int64) result_double;
 
    PG_RETURN_INTERVAL_P(result);
+
+out_of_range:
+   ereport(ERROR,
+           errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+           errmsg("interval out of range"));
+
+   PG_RETURN_NULL();           /* keep compiler quiet */
 }
 
 

diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index 8e2d5355435c8c064ad892e356158046735922b6..71a40515ce1b37a278963c7c6585d745701888e1 100644 (file)
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -357,6 +357,19 @@ SELECT * FROM INTERVAL_TBL;
  @ 5 mons 12 hours
 (10 rows)
 
+-- multiplication and division overflow test cases
+SELECT '3000000 months'::interval * 1000;
+ERROR:  interval out of range
+SELECT '3000000 months'::interval / 0.001;
+ERROR:  interval out of range
+SELECT '3000000 days'::interval * 1000;
+ERROR:  interval out of range
+SELECT '3000000 days'::interval / 0.001;
+ERROR:  interval out of range
+SELECT '1 month 2146410 days'::interval * 1000.5002;
+ERROR:  interval out of range
+SELECT make_interval(0, 0, 0, 0, 0, 0, 4611686018427.387904) / 0.1;
+ERROR:  interval out of range
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval

diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 6d532398bd694406ad9d8d8baa9dff547ab46681..0257dc6c3e46e7d3a211023324f496eb4e2f95db 100644 (file)
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -129,6 +129,14 @@ SET IntervalStyle to postgres_verbose;
 
 SELECT * FROM INTERVAL_TBL;
 
+-- multiplication and division overflow test cases
+SELECT '3000000 months'::interval * 1000;
+SELECT '3000000 months'::interval / 0.001;
+SELECT '3000000 days'::interval * 1000;
+SELECT '3000000 days'::interval / 0.001;
+SELECT '1 month 2146410 days'::interval * 1000.5002;
+SELECT make_interval(0, 0, 0, 0, 0, 0, 4611686018427.387904) / 0.1;
+
 -- test avg(interval), which is somewhat fragile since people have been
 -- known to change the allowed input syntax for type interval without
 -- updating pg_aggregate.agginitval