Detect more overflows in timestamp[tz]_pl_interval.

In commit 25cd2d640 I (tgl) opined that "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".  This is demonstrably wrong however
for the microseconds field, and given that discovery it seems prudent
to be paranoid about the months addition as well.

Report and patch by Joseph Koshakow.  As before, back-patch to all
supported branches.  (However, the test case doesn't work before
v15 because we didn't allow wider-than-int32 numbers in interval
literals.  A variant test could probably be built that fits within
that restriction, but it didn't seem worth the trouble.)

Discussion: https://postgr.es/m/CAAvxfHf77sRHKoEzUw9_cMYSpbpNS2C+J_+8Dq4+0oi8iKopeA@mail.gmail.com

diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index b41a08878a09452067fac5605999009b97ceb276..d3f0398e18ed53af8764920db9710c85a71914eb 100644 (file)
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -2859,7 +2859,10 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
                        (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                         errmsg("timestamp out of range")));
 
-           tm->tm_mon += span->month;
+           if (pg_add_s32_overflow(tm->tm_mon, span->month, &tm->tm_mon))
+               ereport(ERROR,
+                       (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+                        errmsg("timestamp out of range")));
            if (tm->tm_mon > MONTHS_PER_YEAR)
            {
                tm->tm_year += (tm->tm_mon - 1) / MONTHS_PER_YEAR;
@@ -2911,7 +2914,10 @@ timestamp_pl_interval(PG_FUNCTION_ARGS)
                         errmsg("timestamp out of range")));
        }
 
-       timestamp += span->time;
+       if (pg_add_s64_overflow(timestamp, span->time, &timestamp))
+           ereport(ERROR,
+                   (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+                    errmsg("timestamp out of range")));
 
        if (!IS_VALID_TIMESTAMP(timestamp))
            ereport(ERROR,
@@ -2973,7 +2979,10 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
                        (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
                         errmsg("timestamp out of range")));
 
-           tm->tm_mon += span->month;
+           if (pg_add_s32_overflow(tm->tm_mon, span->month, &tm->tm_mon))
+               ereport(ERROR,
+                       (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+                        errmsg("timestamp out of range")));
            if (tm->tm_mon > MONTHS_PER_YEAR)
            {
                tm->tm_year += (tm->tm_mon - 1) / MONTHS_PER_YEAR;
@@ -3032,7 +3041,10 @@ timestamptz_pl_interval(PG_FUNCTION_ARGS)
                         errmsg("timestamp out of range")));
        }
 
-       timestamp += span->time;
+       if (pg_add_s64_overflow(timestamp, span->time, &timestamp))
+           ereport(ERROR,
+                   (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
+                    errmsg("timestamp out of range")));
 
        if (!IS_VALID_TIMESTAMP(timestamp))
            ereport(ERROR,