On Mon, Feb 14, 2022 at 04:57:07PM -0500, Joseph Koshakow wrote:
> On Mon, Feb 14, 2022 at 2:15 PM Nathan Bossart <nathandboss...@gmail.com>
> wrote:
>> Makes sense. So we could likely avoid it for justify_interval, but the
>> others are at the mercy of the interval implementation.
>
> I'm not entirely sure what you mean by "it", but for both
> justify_interval and justify_days this commit throws an error if we
> try to set the months field above 2^31.
>
>> +SELECT justify_days(interval '2147483647 months 30 days');
>> +ERROR: interval out of range
>> +SELECT justify_interval(interval '2147483647 months 30 days');
>> +ERROR: interval out of range
>
> That's what these are testing.
I think it's possible to avoid overflow in justify_interval() in some cases
by pre-justifying the days. I've attached a patch to demonstrate.
--
Nathan Bossart
Amazon Web Services: https://aws.amazon.com
>From d566fcc8cf0179bb915db828b528df55484b63dc Mon Sep 17 00:00:00 2001
From: Joseph Koshakow <kosh...@gmail.com>
Date: Sun, 13 Feb 2022 13:26:16 -0500
Subject: [PATCH v2 1/1] Check for overflow in justify_interval functions
justify_interval, justify_hours, and justify_days didn't check for
overflow when moving hours to days or days to hours. This commit adds
check for overflow and returns an appropriate error.
---
src/backend/utils/adt/timestamp.c | 32 ++++++++++++++++++++---
src/test/regress/expected/interval.out | 36 ++++++++++++++++++++++++++
src/test/regress/sql/interval.sql | 12 +++++++++
3 files changed, 76 insertions(+), 4 deletions(-)
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 36f8a84bcc..8cda47e9a4 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -2717,12 +2717,30 @@ interval_justify_interval(PG_FUNCTION_ARGS)
result->day = span->day;
result->time = span->time;
+ /* pre-justify days if it might prevent overflow */
+ if ((result->day > 0 && result->time > 0) ||
+ (result->day < 0 && result->time < 0))
+ {
+ wholemonth = result->day / DAYS_PER_MONTH;
+ result->day -= wholemonth * DAYS_PER_MONTH;
+ if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+ errmsg("interval out of range")));
+ }
+
TMODULO(result->time, wholeday, USECS_PER_DAY);
- result->day += wholeday; /* could overflow... */
+ if (pg_add_s32_overflow(result->day, wholeday, &result->day))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+ errmsg("interval out of range")));
wholemonth = result->day / DAYS_PER_MONTH;
result->day -= wholemonth * DAYS_PER_MONTH;
- result->month += wholemonth;
+ if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+ errmsg("interval out of range")));
if (result->month > 0 &&
(result->day < 0 || (result->day == 0 && result->time < 0)))
@@ -2772,7 +2790,10 @@ interval_justify_hours(PG_FUNCTION_ARGS)
result->time = span->time;
TMODULO(result->time, wholeday, USECS_PER_DAY);
- result->day += wholeday; /* could overflow... */
+ if (pg_add_s32_overflow(result->day, wholeday, &result->day))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+ errmsg("interval out of range")));
if (result->day > 0 && result->time < 0)
{
@@ -2808,7 +2829,10 @@ interval_justify_days(PG_FUNCTION_ARGS)
wholemonth = result->day / DAYS_PER_MONTH;
result->day -= wholemonth * DAYS_PER_MONTH;
- result->month += wholemonth;
+ if (pg_add_s32_overflow(result->month, wholemonth, &result->month))
+ ereport(ERROR,
+ (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+ errmsg("interval out of range")));
if (result->month > 0 && result->day < 0)
{
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index accd4a7d90..146f7c55d0 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -396,6 +396,10 @@ SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as
@ 7 mons 6 days 5 hours 4 mins 3 secs
(1 row)
+SELECT justify_hours(interval '2147483647 days 24 hrs');
+ERROR: interval out of range
+SELECT justify_days(interval '2147483647 months 30 days');
+ERROR: interval out of range
-- test justify_interval()
SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
1 month -1 hour
@@ -403,6 +407,38 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
@ 29 days 23 hours
(1 row)
+SELECT justify_interval(interval '2147483647 days 24 hrs');
+ justify_interval
+-------------------------------
+ @ 5965232 years 4 mons 8 days
+(1 row)
+
+SELECT justify_interval(interval '-2147483648 days -24 hrs');
+ justify_interval
+-----------------------------------
+ @ 5965232 years 4 mons 9 days ago
+(1 row)
+
+SELECT justify_interval(interval '2147483647 months 30 days');
+ERROR: interval out of range
+SELECT justify_interval(interval '-2147483648 months -30 days');
+ERROR: interval out of range
+SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+ justify_interval
+----------------------------------
+ @ 178956970 years 7 mons 29 days
+(1 row)
+
+SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+ justify_interval
+--------------------------------------
+ @ 178956970 years 8 mons 29 days ago
+(1 row)
+
+SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+ERROR: interval out of range
+SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+ERROR: interval out of range
-- test fractional second input, and detection of duplicate units
SET DATESTYLE = 'ISO';
SET IntervalStyle TO postgres;
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index 6d532398bd..c31f0eec05 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -149,10 +149,22 @@ select '100000000y 10mon -1000000000d -100000h -10min -10.000001s ago'::interval
SELECT justify_hours(interval '6 months 3 days 52 hours 3 minutes 2 seconds') as "6 mons 5 days 4 hours 3 mins 2 seconds";
SELECT justify_days(interval '6 months 36 days 5 hours 4 minutes 3 seconds') as "7 mons 6 days 5 hours 4 mins 3 seconds";
+SELECT justify_hours(interval '2147483647 days 24 hrs');
+SELECT justify_days(interval '2147483647 months 30 days');
+
-- test justify_interval()
SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
+SELECT justify_interval(interval '2147483647 days 24 hrs');
+SELECT justify_interval(interval '-2147483648 days -24 hrs');
+SELECT justify_interval(interval '2147483647 months 30 days');
+SELECT justify_interval(interval '-2147483648 months -30 days');
+SELECT justify_interval(interval '2147483647 months 30 days -24 hrs');
+SELECT justify_interval(interval '-2147483648 months -30 days 24 hrs');
+SELECT justify_interval(interval '2147483647 months -30 days 1440 hrs');
+SELECT justify_interval(interval '-2147483648 months 30 days -1440 hrs');
+
-- test fractional second input, and detection of duplicate units
SET DATESTYLE = 'ISO';
SET IntervalStyle TO postgres;
--
2.25.1
