Fix mis-rounding and overflow hazards in date_bin().

In the case where the target timestamp is before the origin timestamp
and their difference is already an exact multiple of the stride, the
code incorrectly subtracted the stride anyway.

Also detect several integer-overflow cases that previously produced
bogus results.  (The submitted patch tried to avoid overflow, but
I'm not convinced it's right, and problematic cases are so far out of
the plausibly-useful range that they don't seem worth sweating over.
Let's just use overflow-detecting arithmetic and throw errors.)

timestamp_bin() and timestamptz_bin() are basically identical and
so had identical bugs.  Fix both.

Report and patch by Moaaz Assali, adjusted some by me.  Back-patch
to v14 where date_bin() was introduced.

Discussion: https://postgr.es/m/CALkF+nvtuas-2kydG-WfofbRSJpyODAJWun==W-yO5j2R4meqA@mail.gmail.com

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 6dbc27a48d156838a8b3fde6bd36057674f2f4aa..78d748cddaf43a5175296bdb8dd4537b46eb74b6 100644 (file)
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -3870,8 +3870,9 @@ timestamp_bin(PG_FUNCTION_ARGS)
    Timestamp   timestamp = PG_GETARG_TIMESTAMP(1);
    Timestamp   origin = PG_GETARG_TIMESTAMP(2);
    Timestamp   result,
-               tm_diff,
                stride_usecs,
+               tm_diff,
+               tm_modulo,
                tm_delta;
 
    if (TIMESTAMP_NOT_FINITE(timestamp))
@@ -3887,24 +3888,40 @@ timestamp_bin(PG_FUNCTION_ARGS)
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("timestamps cannot be binned into intervals containing months or years")));
 
-   stride_usecs = stride->day * USECS_PER_DAY + stride->time;
+   if (unlikely(pg_mul_s64_overflow(stride->day, USECS_PER_DAY, &stride_usecs)) ||
+       unlikely(pg_add_s64_overflow(stride_usecs, stride->time, &stride_usecs)))
+       ereport(ERROR,
+               (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+                errmsg("interval out of range")));
 
    if (stride_usecs <= 0)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("stride must be greater than zero")));
 
-   tm_diff = timestamp - origin;
-   tm_delta = tm_diff - tm_diff % stride_usecs;
+   if (unlikely(pg_sub_s64_overflow(timestamp, origin, &tm_diff)))
+       ereport(ERROR,
+               (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+                errmsg("interval out of range")));
+
+   /* These calculations cannot overflow */
+   tm_modulo = tm_diff % stride_usecs;
+   tm_delta = tm_diff - tm_modulo;
+   result = origin + tm_delta;
 
    /*
-    * Make sure the returned timestamp is at the start of the bin, even if
-    * the origin is in the future.
+    * We want to round towards -infinity, not 0, when tm_diff is negative and
+    * not a multiple of stride_usecs.  This adjustment *can* cause overflow,
+    * since the result might now be out of the range origin .. timestamp.
     */
-   if (origin > timestamp && stride_usecs > 1)
-       tm_delta -= stride_usecs;
-
-   result = origin + tm_delta;
+   if (tm_modulo < 0)
+   {
+       if (unlikely(pg_sub_s64_overflow(result, stride_usecs, &result)) ||
+           !IS_VALID_TIMESTAMP(result))
+           ereport(ERROR,
+                   (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+                    errmsg("timestamp out of range")));
+   }
 
    PG_RETURN_TIMESTAMP(result);
 }
@@ -4055,6 +4072,7 @@ timestamptz_bin(PG_FUNCTION_ARGS)
    TimestampTz result,
                stride_usecs,
                tm_diff,
+               tm_modulo,
                tm_delta;
 
    if (TIMESTAMP_NOT_FINITE(timestamp))
@@ -4070,24 +4088,40 @@ timestamptz_bin(PG_FUNCTION_ARGS)
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("timestamps cannot be binned into intervals containing months or years")));
 
-   stride_usecs = stride->day * USECS_PER_DAY + stride->time;
+   if (unlikely(pg_mul_s64_overflow(stride->day, USECS_PER_DAY, &stride_usecs)) ||
+       unlikely(pg_add_s64_overflow(stride_usecs, stride->time, &stride_usecs)))
+       ereport(ERROR,
+               (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+                errmsg("interval out of range")));
 
    if (stride_usecs <= 0)
        ereport(ERROR,
                (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                 errmsg("stride must be greater than zero")));
 
-   tm_diff = timestamp - origin;
-   tm_delta = tm_diff - tm_diff % stride_usecs;
+   if (unlikely(pg_sub_s64_overflow(timestamp, origin, &tm_diff)))
+       ereport(ERROR,
+               (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+                errmsg("interval out of range")));
+
+   /* These calculations cannot overflow */
+   tm_modulo = tm_diff % stride_usecs;
+   tm_delta = tm_diff - tm_modulo;
+   result = origin + tm_delta;
 
    /*
-    * Make sure the returned timestamp is at the start of the bin, even if
-    * the origin is in the future.
+    * We want to round towards -infinity, not 0, when tm_diff is negative and
+    * not a multiple of stride_usecs.  This adjustment *can* cause overflow,
+    * since the result might now be out of the range origin .. timestamp.
     */
-   if (origin > timestamp && stride_usecs > 1)
-       tm_delta -= stride_usecs;
-
-   result = origin + tm_delta;
+   if (tm_modulo < 0)
+   {
+       if (unlikely(pg_sub_s64_overflow(result, stride_usecs, &result)) ||
+           !IS_VALID_TIMESTAMP(result))
+           ereport(ERROR,
+                   (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+                    errmsg("timestamp out of range")));
+   }
 
    PG_RETURN_TIMESTAMPTZ(result);
 }

diff --git a/src/test/regress/expected/timestamp.out b/src/test/regress/expected/timestamp.out
index 79f81809558ecbbbc5e65b5a96a35a5a32da2897..2ee8712a96c24be71e806a37789cc33ee975ca40 100644 (file)
--- a/src/test/regress/expected/timestamp.out
+++ b/src/test/regress/expected/timestamp.out
@@ -699,6 +699,13 @@ SELECT date_bin('5 min'::interval, timestamp '2020-02-01 01:01:01', timestamp '2
  Sat Feb 01 00:57:30 2020
 (1 row)
 
+-- test roundoff edge case when source < origin
+SELECT date_bin('30 minutes'::interval, timestamp '2024-02-01 15:00:00', timestamp '2024-02-01 17:00:00');
+         date_bin         
+--------------------------
+ Thu Feb 01 15:00:00 2024
+(1 row)
+
 -- disallow intervals with months or years
 SELECT date_bin('5 months'::interval, timestamp '2020-02-01 01:01:01', timestamp '2001-01-01');
 ERROR:  timestamps cannot be binned into intervals containing months or years
@@ -710,6 +717,13 @@ ERROR:  stride must be greater than zero
 -- disallow negative intervals
 SELECT date_bin('-2 days'::interval, timestamp '1970-01-01 01:00:00' , timestamp '1970-01-01 00:00:00');
 ERROR:  stride must be greater than zero
+-- test overflow cases
+select date_bin('15 minutes'::interval, timestamp '294276-12-30', timestamp '4000-12-20 BC');
+ERROR:  interval out of range
+select date_bin('200000000 days'::interval, '2024-02-01'::timestamp, '2024-01-01'::timestamp);
+ERROR:  interval out of range
+select date_bin('365000 days'::interval, '4400-01-01 BC'::timestamp, '4000-01-01 BC'::timestamp);
+ERROR:  timestamp out of range
 -- Test casting within a BETWEEN qualifier
 SELECT d1 - timestamp without time zone '1997-01-02' AS diff
   FROM TIMESTAMP_TBL

diff --git a/src/test/regress/expected/timestamptz.out b/src/test/regress/expected/timestamptz.out
index a0df947e2716d9730a3176c7ff29cc76ffadc5a4..812a8365112a6147195ad407e945895b85baa847 100644 (file)
--- a/src/test/regress/expected/timestamptz.out
+++ b/src/test/regress/expected/timestamptz.out
@@ -743,6 +743,13 @@ SELECT date_bin('5 min'::interval, timestamptz '2020-02-01 01:01:01+00', timesta
  Fri Jan 31 16:57:30 2020 PST
 (1 row)
 
+-- test roundoff edge case when source < origin
+SELECT date_bin('30 minutes'::interval, timestamptz '2024-02-01 15:00:00', timestamptz '2024-02-01 17:00:00');
+           date_bin           
+------------------------------
+ Thu Feb 01 15:00:00 2024 PST
+(1 row)
+
 -- disallow intervals with months or years
 SELECT date_bin('5 months'::interval, timestamp with time zone '2020-02-01 01:01:01+00', timestamp with time zone '2001-01-01+00');
 ERROR:  timestamps cannot be binned into intervals containing months or years
@@ -754,6 +761,13 @@ ERROR:  stride must be greater than zero
 -- disallow negative intervals
 SELECT date_bin('-2 days'::interval, timestamp with time zone '1970-01-01 01:00:00+00' , timestamp with time zone '1970-01-01 00:00:00+00');
 ERROR:  stride must be greater than zero
+-- test overflow cases
+select date_bin('15 minutes'::interval, timestamptz '294276-12-30', timestamptz '4000-12-20 BC');
+ERROR:  interval out of range
+select date_bin('200000000 days'::interval, '2024-02-01'::timestamptz, '2024-01-01'::timestamptz);
+ERROR:  interval out of range
+select date_bin('365000 days'::interval, '4400-01-01 BC'::timestamptz, '4000-01-01 BC'::timestamptz);
+ERROR:  timestamp out of range
 -- Test casting within a BETWEEN qualifier
 SELECT d1 - timestamp with time zone '1997-01-02' AS diff
   FROM TIMESTAMPTZ_TBL

diff --git a/src/test/regress/sql/timestamp.sql b/src/test/regress/sql/timestamp.sql
index ebc969f36cf6e5f88b2e160b7dc345c478adce58..bc378036fe8a07c0f39661156cbec21d096f7fef 100644 (file)
--- a/src/test/regress/sql/timestamp.sql
+++ b/src/test/regress/sql/timestamp.sql
@@ -259,6 +259,9 @@ FROM (
 -- shift bins using the origin parameter:
 SELECT date_bin('5 min'::interval, timestamp '2020-02-01 01:01:01', timestamp '2020-02-01 00:02:30');
 
+-- test roundoff edge case when source < origin
+SELECT date_bin('30 minutes'::interval, timestamp '2024-02-01 15:00:00', timestamp '2024-02-01 17:00:00');
+
 -- disallow intervals with months or years
 SELECT date_bin('5 months'::interval, timestamp '2020-02-01 01:01:01', timestamp '2001-01-01');
 SELECT date_bin('5 years'::interval,  timestamp '2020-02-01 01:01:01', timestamp '2001-01-01');
@@ -269,6 +272,11 @@ SELECT date_bin('0 days'::interval, timestamp '1970-01-01 01:00:00' , timestamp
 -- disallow negative intervals
 SELECT date_bin('-2 days'::interval, timestamp '1970-01-01 01:00:00' , timestamp '1970-01-01 00:00:00');
 
+-- test overflow cases
+select date_bin('15 minutes'::interval, timestamp '294276-12-30', timestamp '4000-12-20 BC');
+select date_bin('200000000 days'::interval, '2024-02-01'::timestamp, '2024-01-01'::timestamp);
+select date_bin('365000 days'::interval, '4400-01-01 BC'::timestamp, '4000-01-01 BC'::timestamp);
+
 -- Test casting within a BETWEEN qualifier
 SELECT d1 - timestamp without time zone '1997-01-02' AS diff
   FROM TIMESTAMP_TBL

diff --git a/src/test/regress/sql/timestamptz.sql b/src/test/regress/sql/timestamptz.sql
index bce70fb21f7a9ca1e451bbf72c59c0e12462c8f2..62593d8c6443afa85b351d86b1f19e73b8c5d864 100644 (file)
--- a/src/test/regress/sql/timestamptz.sql
+++ b/src/test/regress/sql/timestamptz.sql
@@ -234,6 +234,9 @@ FROM (
 -- shift bins using the origin parameter:
 SELECT date_bin('5 min'::interval, timestamptz '2020-02-01 01:01:01+00', timestamptz '2020-02-01 00:02:30+00');
 
+-- test roundoff edge case when source < origin
+SELECT date_bin('30 minutes'::interval, timestamptz '2024-02-01 15:00:00', timestamptz '2024-02-01 17:00:00');
+
 -- disallow intervals with months or years
 SELECT date_bin('5 months'::interval, timestamp with time zone '2020-02-01 01:01:01+00', timestamp with time zone '2001-01-01+00');
 SELECT date_bin('5 years'::interval,  timestamp with time zone '2020-02-01 01:01:01+00', timestamp with time zone '2001-01-01+00');
@@ -244,6 +247,11 @@ SELECT date_bin('0 days'::interval, timestamp with time zone '1970-01-01 01:00:0
 -- disallow negative intervals
 SELECT date_bin('-2 days'::interval, timestamp with time zone '1970-01-01 01:00:00+00' , timestamp with time zone '1970-01-01 00:00:00+00');
 
+-- test overflow cases
+select date_bin('15 minutes'::interval, timestamptz '294276-12-30', timestamptz '4000-12-20 BC');
+select date_bin('200000000 days'::interval, '2024-02-01'::timestamptz, '2024-01-01'::timestamptz);
+select date_bin('365000 days'::interval, '4400-01-01 BC'::timestamptz, '4000-01-01 BC'::timestamptz);
+
 -- Test casting within a BETWEEN qualifier
 SELECT d1 - timestamp with time zone '1997-01-02' AS diff
   FROM TIMESTAMPTZ_TBL