From f6e72dc9cc8b8f480ea4a982662c3695ddc5a549 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 7 Nov 2019 11:22:52 -0500
Subject: [PATCH] Fix integer-overflow edge case detection in interval_mul and
pgbench.
This patch adopts the overflow check logic introduced by commit cbdb8b4c0
into two more places. interval_mul() failed to notice if it computed a
new microseconds value that was one more than INT64_MAX, and pgbench's
double-to-int64 logic had the same sorts of edge-case problems that
cbdb8b4c0 fixed in the core code.
To make this easier to get right in future, put the guts of the checks
into new macros in c.h, and add commentary about how to use the macros
correctly.
Back-patch to all supported branches, as we did with the previous fix.
Yuya Watari
Discussion: https://postgr.es/m/CAJ2pMkbkkFw2hb9Qb1Zj8d06EhWAQXFLy73St4qWv6aX=vqnjw@mail.gmail.com
---
src/backend/utils/adt/float.c | 44 +++++---------------------
src/backend/utils/adt/int8.c | 22 +++----------
src/backend/utils/adt/timestamp.c | 2 +-
src/bin/pgbench/pgbench.c | 4 +--
src/include/c.h | 24 ++++++++++++++
src/test/regress/expected/interval.out | 3 ++
src/test/regress/sql/interval.sql | 3 ++
7 files changed, 45 insertions(+), 57 deletions(-)
diff --git a/src/backend/utils/adt/float.c b/src/backend/utils/adt/float.c
index 7540ca22efe..f2521999ac0 100644
--- a/src/backend/utils/adt/float.c
+++ b/src/backend/utils/adt/float.c
@@ -1206,15 +1206,8 @@ dtoi4(PG_FUNCTION_ARGS)
*/
num = rint(num);
- /*
- * Range check. We must be careful here that the boundary values are
- * expressed exactly in the float domain. We expect PG_INT32_MIN to be an
- * exact power of 2, so it will be represented exactly; but PG_INT32_MAX
- * isn't, and might get rounded off, so avoid using it.
- */
- if (unlikely(num < (float8) PG_INT32_MIN ||
- num >= -((float8) PG_INT32_MIN) ||
- isnan(num)))
+ /* Range check */
+ if (unlikely(isnan(num) || !FLOAT8_FITS_IN_INT32(num)))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
@@ -1238,15 +1231,8 @@ dtoi2(PG_FUNCTION_ARGS)
*/
num = rint(num);
- /*
- * Range check. We must be careful here that the boundary values are
- * expressed exactly in the float domain. We expect PG_INT16_MIN to be an
- * exact power of 2, so it will be represented exactly; but PG_INT16_MAX
- * isn't, and might get rounded off, so avoid using it.
- */
- if (unlikely(num < (float8) PG_INT16_MIN ||
- num >= -((float8) PG_INT16_MIN) ||
- isnan(num)))
+ /* Range check */
+ if (unlikely(isnan(num) || !FLOAT8_FITS_IN_INT16(num)))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("smallint out of range")));
@@ -1294,15 +1280,8 @@ ftoi4(PG_FUNCTION_ARGS)
*/
num = rint(num);
- /*
- * Range check. We must be careful here that the boundary values are
- * expressed exactly in the float domain. We expect PG_INT32_MIN to be an
- * exact power of 2, so it will be represented exactly; but PG_INT32_MAX
- * isn't, and might get rounded off, so avoid using it.
- */
- if (unlikely(num < (float4) PG_INT32_MIN ||
- num >= -((float4) PG_INT32_MIN) ||
- isnan(num)))
+ /* Range check */
+ if (unlikely(isnan(num) || !FLOAT4_FITS_IN_INT32(num)))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("integer out of range")));
@@ -1326,15 +1305,8 @@ ftoi2(PG_FUNCTION_ARGS)
*/
num = rint(num);
- /*
- * Range check. We must be careful here that the boundary values are
- * expressed exactly in the float domain. We expect PG_INT16_MIN to be an
- * exact power of 2, so it will be represented exactly; but PG_INT16_MAX
- * isn't, and might get rounded off, so avoid using it.
- */
- if (unlikely(num < (float4) PG_INT16_MIN ||
- num >= -((float4) PG_INT16_MIN) ||
- isnan(num)))
+ /* Range check */
+ if (unlikely(isnan(num) || !FLOAT4_FITS_IN_INT16(num)))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("smallint out of range")));
diff --git a/src/backend/utils/adt/int8.c b/src/backend/utils/adt/int8.c
index 0ff9394a2fb..93acabce42c 100644
--- a/src/backend/utils/adt/int8.c
+++ b/src/backend/utils/adt/int8.c
@@ -1216,15 +1216,8 @@ dtoi8(PG_FUNCTION_ARGS)
*/
num = rint(num);
- /*
- * Range check. We must be careful here that the boundary values are
- * expressed exactly in the float domain. We expect PG_INT64_MIN to be an
- * exact power of 2, so it will be represented exactly; but PG_INT64_MAX
- * isn't, and might get rounded off, so avoid using it.
- */
- if (unlikely(num < (float8) PG_INT64_MIN ||
- num >= -((float8) PG_INT64_MIN) ||
- isnan(num)))
+ /* Range check */
+ if (unlikely(isnan(num) || !FLOAT8_FITS_IN_INT64(num)))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
@@ -1258,15 +1251,8 @@ ftoi8(PG_FUNCTION_ARGS)
*/
num = rint(num);
- /*
- * Range check. We must be careful here that the boundary values are
- * expressed exactly in the float domain. We expect PG_INT64_MIN to be an
- * exact power of 2, so it will be represented exactly; but PG_INT64_MAX
- * isn't, and might get rounded off, so avoid using it.
- */
- if (unlikely(num < (float4) PG_INT64_MIN ||
- num >= -((float4) PG_INT64_MIN) ||
- isnan(num)))
+ /* Range check */
+ if (unlikely(isnan(num) || !FLOAT4_FITS_IN_INT64(num)))
ereport(ERROR,
(errcode(ERRCODE_NUMERIC_VALUE_OUT_OF_RANGE),
errmsg("bigint out of range")));
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
index 5861ffbbc97..68db766caba 100644
--- a/src/backend/utils/adt/timestamp.c
+++ b/src/backend/utils/adt/timestamp.c
@@ -3219,7 +3219,7 @@ interval_mul(PG_FUNCTION_ARGS)
/* cascade units down */
result->day += (int32) month_remainder_days;
result_double = rint(span->time * factor + sec_remainder * USECS_PER_SEC);
- if (result_double > PG_INT64_MAX || result_double < PG_INT64_MIN)
+ if (isnan(result_double) || !FLOAT8_FITS_IN_INT64(result_double))
ereport(ERROR,
(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
errmsg("interval out of range")));
diff --git a/src/bin/pgbench/pgbench.c b/src/bin/pgbench/pgbench.c
index 8b84658ccda..e0e22140758 100644
--- a/src/bin/pgbench/pgbench.c
+++ b/src/bin/pgbench/pgbench.c
@@ -1651,9 +1651,9 @@ coerceToInt(PgBenchValue *pval, int64 *ival)
}
else if (pval->type == PGBT_DOUBLE)
{
- double dval = pval->u.dval;
+ double dval = rint(pval->u.dval);
- if (dval < PG_INT64_MIN || PG_INT64_MAX < dval)
+ if (isnan(dval) || !FLOAT8_FITS_IN_INT64(dval))
{
fprintf(stderr, "double to int overflow for %f\n", dval);
return false;
diff --git a/src/include/c.h b/src/include/c.h
index 2a082afab11..0fcd6b193c7 100644
--- a/src/include/c.h
+++ b/src/include/c.h
@@ -1016,6 +1016,30 @@ extern void ExceptionalCondition(const char *conditionName,
*_start++ = 0; \
} while (0)
+/*
+ * Macros for range-checking float values before converting to integer.
+ * We must be careful here that the boundary values are expressed exactly
+ * in the float domain. PG_INTnn_MIN is an exact power of 2, so it will
+ * be represented exactly; but PG_INTnn_MAX isn't, and might get rounded
+ * off, so avoid using that.
+ * The input must be rounded to an integer beforehand, typically with rint(),
+ * else we might draw the wrong conclusion about close-to-the-limit values.
+ * These macros will do the right thing for Inf, but not necessarily for NaN,
+ * so check isnan(num) first if that's a possibility.
+ */
+#define FLOAT4_FITS_IN_INT16(num) \
+ ((num) >= (float4) PG_INT16_MIN && (num) < -((float4) PG_INT16_MIN))
+#define FLOAT4_FITS_IN_INT32(num) \
+ ((num) >= (float4) PG_INT32_MIN && (num) < -((float4) PG_INT32_MIN))
+#define FLOAT4_FITS_IN_INT64(num) \
+ ((num) >= (float4) PG_INT64_MIN && (num) < -((float4) PG_INT64_MIN))
+#define FLOAT8_FITS_IN_INT16(num) \
+ ((num) >= (float8) PG_INT16_MIN && (num) < -((float8) PG_INT16_MIN))
+#define FLOAT8_FITS_IN_INT32(num) \
+ ((num) >= (float8) PG_INT32_MIN && (num) < -((float8) PG_INT32_MIN))
+#define FLOAT8_FITS_IN_INT64(num) \
+ ((num) >= (float8) PG_INT64_MIN && (num) < -((float8) PG_INT64_MIN))
+
/* ----------------------------------------------------------------
* Section 8: random stuff
diff --git a/src/test/regress/expected/interval.out b/src/test/regress/expected/interval.out
index f88f34550ad..f772909e49c 100644
--- a/src/test/regress/expected/interval.out
+++ b/src/test/regress/expected/interval.out
@@ -232,6 +232,9 @@ INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483648 years');
ERROR: interval out of range
LINE 1: INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483648 years'...
^
+-- Test edge-case overflow detection in interval multiplication
+select extract(epoch from '256 microseconds'::interval * (2^55)::float8);
+ERROR: interval out of range
SELECT r1.*, r2.*
FROM INTERVAL_TBL_OF r1, INTERVAL_TBL_OF r2
WHERE r1.f1 > r2.f1
diff --git a/src/test/regress/sql/interval.sql b/src/test/regress/sql/interval.sql
index bc5537d1b9c..eb1e84f053e 100644
--- a/src/test/regress/sql/interval.sql
+++ b/src/test/regress/sql/interval.sql
@@ -73,6 +73,9 @@ INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483649 days');
INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('2147483647 years');
INSERT INTO INTERVAL_TBL_OF (f1) VALUES ('-2147483648 years');
+-- Test edge-case overflow detection in interval multiplication
+select extract(epoch from '256 microseconds'::interval * (2^55)::float8);
+
SELECT r1.*, r2.*
FROM INTERVAL_TBL_OF r1, INTERVAL_TBL_OF r2
WHERE r1.f1 > r2.f1
--
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