From a898b409f66f956e99694710f537829db02652c0 Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Tue, 29 Mar 2016 17:21:12 -0400 Subject: [PATCH] Fix interval_mul() to not produce insane results. interval_mul() attempts to prevent its calculations from producing silly results, but it forgot that zero times infinity yields NaN in IEEE arithmetic. Hence, a case like '1 second'::interval * 'infinity'::float8 produced a NaN for the months product, which didn't trigger the range check, resulting in bogus and possibly platform-dependent output. This isn't terribly obvious to the naked eye because if you try that exact case, you get "interval out of range" which is what you expect --- but if you look closer, the error is coming from interval_out not interval_mul. interval_mul has allowed a bogus value into the system. Fix by adding isnan tests. Noted while testing Vitaly Burovoy's fix for infinity input to to_timestamp(). Given the lack of field complaints, I doubt this is worth a back-patch. --- src/backend/utils/adt/timestamp.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c index b9c26b6854..7456808a42 100644 --- a/src/backend/utils/adt/timestamp.c +++ b/src/backend/utils/adt/timestamp.c @@ -3351,14 +3351,16 @@ interval_mul(PG_FUNCTION_ARGS) result = (Interval *) palloc(sizeof(Interval)); result_double = span->month * factor; - if (result_double > INT_MAX || result_double < INT_MIN) + if (isnan(result_double) || + result_double > INT_MAX || result_double < INT_MIN) ereport(ERROR, (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE), errmsg("interval out of range"))); result->month = (int32) result_double; result_double = span->day * factor; - if (result_double > INT_MAX || result_double < INT_MIN) + if (isnan(result_double) || + result_double > INT_MAX || result_double < INT_MIN) ereport(ERROR, (errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE), errmsg("interval out of range")));