From 3eb8a87f6e71b92ccb6618aac7f752a5e4e8d1dc Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Fri, 26 Jan 2024 13:39:37 -0500 Subject: [PATCH] Detect Julian-date overflow in timestamp[tz]_pl_interval. We perform addition of the days field of an interval via arithmetic on the Julian-date representation of the timestamp's date. This step is subject to int32 overflow, and we also should not let the Julian date become very negative, for fear of weird results from j2date. (In the timestamptz case, allow a Julian date of -1 to pass, since it might convert back to zero after timezone rotation.) The additions of the months and microseconds fields could also overflow, of course. However, I believe we need no additional checks there; the existing range checks should catch such cases. The difficulty here is that j2date's magic modular arithmetic could produce something that looks like it's in-range. Per bug #18313 from Christian Maurer. This has been wrong for a long time, so back-patch to all supported branches. Discussion: https://postgr.es/m/18313-64d2c8952d81e84b@postgresql.org --- src/backend/utils/adt/timestamp.c | 27 ++++++++++++++++++++++---- src/test/regress/expected/horology.out | 4 ++++ src/test/regress/sql/horology.sql | 2 ++ 3 files changed, 29 insertions(+), 4 deletions(-) diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c index a18e1d2b29..6dbc27a48d 100644 --- a/src/backend/utils/adt/timestamp.c +++ b/src/backend/utils/adt/timestamp.c @@ -2893,8 +2893,16 @@ timestamp_pl_interval(PG_FUNCTION_ARGS) (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE), errmsg("timestamp out of range"))); - /* Add days by converting to and from Julian */ - julian = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) + span->day; + /* + * Add days by converting to and from Julian. We need an overflow + * check here since j2date expects a non-negative integer input. + */ + julian = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday); + if (pg_add_s32_overflow(julian, span->day, &julian) || + julian < 0) + ereport(ERROR, + (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE), + errmsg("timestamp out of range"))); j2date(julian, &tm->tm_year, &tm->tm_mon, &tm->tm_mday); if (tm2timestamp(tm, fsec, NULL, ×tamp) != 0) @@ -3001,8 +3009,19 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS) (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE), errmsg("timestamp out of range"))); - /* Add days by converting to and from Julian */ - julian = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday) + span->day; + /* + * Add days by converting to and from Julian. We need an overflow + * check here since j2date expects a non-negative integer input. + * In practice though, it will give correct answers for small + * negative Julian dates; we should allow -1 to avoid + * timezone-dependent failures, as discussed in timestamp.h. + */ + julian = date2j(tm->tm_year, tm->tm_mon, tm->tm_mday); + if (pg_add_s32_overflow(julian, span->day, &julian) || + julian < -1) + ereport(ERROR, + (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE), + errmsg("timestamp out of range"))); j2date(julian, &tm->tm_year, &tm->tm_mon, &tm->tm_mday); tz = DetermineTimeZoneOffset(tm, session_timezone); diff --git a/src/test/regress/expected/horology.out b/src/test/regress/expected/horology.out index 4b865e73f3..f1578711ad 100644 --- a/src/test/regress/expected/horology.out +++ b/src/test/regress/expected/horology.out @@ -373,6 +373,8 @@ SELECT timestamp without time zone 'Jan 1, 4713 BC' + interval '109203489 days' Sun Dec 31 00:00:00 294276 (1 row) +SELECT timestamp without time zone '2000-01-01' - interval '2483590 days' AS "out of range"; +ERROR: timestamp out of range SELECT timestamp without time zone '12/31/294276' - timestamp without time zone '12/23/1999' AS "106751991 Days"; 106751991 Days ------------------ @@ -633,6 +635,8 @@ SELECT timestamp with time zone '1999-12-01' + interval '1 month - 1 second' AS Fri Dec 31 23:59:59 1999 PST (1 row) +SELECT timestamp with time zone '2000-01-01' - interval '2483590 days' AS "out of range"; +ERROR: timestamp out of range SELECT (timestamp with time zone 'today' = (timestamp with time zone 'yesterday' + interval '1 day')) as "True"; True ------ diff --git a/src/test/regress/sql/horology.sql b/src/test/regress/sql/horology.sql index 78091112ca..0ab17d433f 100644 --- a/src/test/regress/sql/horology.sql +++ b/src/test/regress/sql/horology.sql @@ -86,6 +86,7 @@ SELECT timestamp without time zone '1999-12-01' + interval '1 month - 1 second' SELECT timestamp without time zone 'Jan 1, 4713 BC' + interval '106000000 days' AS "Feb 23, 285506"; SELECT timestamp without time zone 'Jan 1, 4713 BC' + interval '107000000 days' AS "Jan 20, 288244"; SELECT timestamp without time zone 'Jan 1, 4713 BC' + interval '109203489 days' AS "Dec 31, 294276"; +SELECT timestamp without time zone '2000-01-01' - interval '2483590 days' AS "out of range"; SELECT timestamp without time zone '12/31/294276' - timestamp without time zone '12/23/1999' AS "106751991 Days"; -- Shorthand values @@ -117,6 +118,7 @@ SELECT timestamp with time zone '1996-03-01' - interval '1 second' AS "Feb 29"; SELECT timestamp with time zone '1999-03-01' - interval '1 second' AS "Feb 28"; SELECT timestamp with time zone '2000-03-01' - interval '1 second' AS "Feb 29"; SELECT timestamp with time zone '1999-12-01' + interval '1 month - 1 second' AS "Dec 31"; +SELECT timestamp with time zone '2000-01-01' - interval '2483590 days' AS "out of range"; SELECT (timestamp with time zone 'today' = (timestamp with time zone 'yesterday' + interval '1 day')) as "True"; SELECT (timestamp with time zone 'today' = (timestamp with time zone 'tomorrow' - interval '1 day')) as "True";