Reject "23:59:60.nnn" in datetime input.

It's intentional that we don't allow values greater than 24 hours,
while we do allow "24:00:00" as well as "23:59:60" as inputs.
However, the range check was miscoded in such a way that it would
accept "23:59:60.nnn" with a nonzero fraction.  For time or timetz,
the stored result would then be greater than "24:00:00" which would
fail dump/reload, not to mention possibly confusing other operations.

Fix by explicitly calculating the result and making sure it does not
exceed 24 hours.  (This calculation is redundant with what will happen
later in tm2time or tm2timetz.  Maybe someday somebody will find that
annoying enough to justify refactoring to avoid the duplication; but
that seems too invasive for a back-patched bug fix, and the cost is
probably unmeasurable anyway.)

Note that this change also rejects such input as the time portion
of a timestamp(tz) value.

Back-patch to v10.  The bug is far older, but to change this pre-v10
we'd need to ensure that the logic behaves sanely with float timestamps,
which is possibly nontrivial due to roundoff considerations.
Doesn't really seem worth troubling with.

Per report from Christoph Berg.

Discussion: https://postgr.es/m/20200520125807.GB296739@msg.df7cb.de

1 files changed, 63 insertions, 7 deletions

diff --git a/src/backend/utils/adt/date.c b/src/backend/utils/adt/date.c
index 87146a21610..fa3c2801f33 100644
--- a/src/backend/utils/adt/date.c
+++ b/src/backend/utils/adt/date.c
@@ -18,6 +18,7 @@
 #include <ctype.h>
 #include <limits.h>
 #include <float.h>
+#include <math.h>
 #include <time.h>
 
 #include "access/hash.h"
@@ -1268,6 +1269,65 @@ tm2time(struct pg_tm *tm, fsec_t fsec, TimeADT *result)
 	return 0;
 }
 
+/* time_overflows()
+ * Check to see if a broken-down time-of-day is out of range.
+ */
+bool
+time_overflows(int hour, int min, int sec, fsec_t fsec)
+{
+	/* Range-check the fields individually. */
+	if (hour < 0 || hour > HOURS_PER_DAY ||
+		min < 0 || min >= MINS_PER_HOUR ||
+		sec < 0 || sec > SECS_PER_MINUTE ||
+		fsec < 0 || fsec > USECS_PER_SEC)
+		return true;
+
+	/*
+	 * Because we allow, eg, hour = 24 or sec = 60, we must check separately
+	 * that the total time value doesn't exceed 24:00:00.
+	 */
+	if ((((((hour * MINS_PER_HOUR + min) * SECS_PER_MINUTE)
+		   + sec) * USECS_PER_SEC) + fsec) > USECS_PER_DAY)
+		return true;
+
+	return false;
+}
+
+/* float_time_overflows()
+ * Same, when we have seconds + fractional seconds as one "double" value.
+ */
+bool
+float_time_overflows(int hour, int min, double sec)
+{
+	/* Range-check the fields individually. */
+	if (hour < 0 || hour > HOURS_PER_DAY ||
+		min < 0 || min >= MINS_PER_HOUR)
+		return true;
+
+	/*
+	 * "sec", being double, requires extra care.  Cope with NaN, and round off
+	 * before applying the range check to avoid unexpected errors due to
+	 * imprecise input.  (We assume rint() behaves sanely with infinities.)
+	 */
+	if (isnan(sec))
+		return true;
+	sec = rint(sec * USECS_PER_SEC);
+	if (sec < 0 || sec > SECS_PER_MINUTE * USECS_PER_SEC)
+		return true;
+
+	/*
+	 * Because we allow, eg, hour = 24 or sec = 60, we must check separately
+	 * that the total time value doesn't exceed 24:00:00.  This must match the
+	 * way that callers will convert the fields to a time.
+	 */
+	if (((((hour * MINS_PER_HOUR + min) * SECS_PER_MINUTE)
+		  * USECS_PER_SEC) + (int64) sec) > USECS_PER_DAY)
+		return true;
+
+	return false;
+}
+
+
 /* time2tm()
  * Convert time data type to POSIX time structure.
  *
@@ -1372,12 +1432,8 @@ make_time(PG_FUNCTION_ARGS)
 	double		sec = PG_GETARG_FLOAT8(2);
 	TimeADT		time;
 
-	/* This should match the checks in DecodeTimeOnly */
-	if (tm_hour < 0 || tm_min < 0 || tm_min > MINS_PER_HOUR - 1 ||
-		sec < 0 || sec > SECS_PER_MINUTE ||
-		tm_hour > HOURS_PER_DAY ||
-	/* test for > 24:00:00 */
-		(tm_hour == HOURS_PER_DAY && (tm_min > 0 || sec > 0)))
+	/* Check for time overflow */
+	if (float_time_overflows(tm_hour, tm_min, sec))
 		ereport(ERROR,
 				(errcode(ERRCODE_DATETIME_FIELD_OVERFLOW),
 				 errmsg("time field value out of range: %d:%02d:%02g",
@@ -1385,7 +1441,7 @@ make_time(PG_FUNCTION_ARGS)
 
 	/* This should match tm2time */
 	time = (((tm_hour * MINS_PER_HOUR + tm_min) * SECS_PER_MINUTE)
-			* USECS_PER_SEC) + rint(sec * USECS_PER_SEC);
+			* USECS_PER_SEC) + (int64) rint(sec * USECS_PER_SEC);
 
 	PG_RETURN_TIMEADT(time);
 }