From f9ec64df8f25ecf69f870682abc6ff0950641610 Mon Sep 17 00:00:00 2001 From: Tom Lane <tgl@sss.pgh.pa.us> Date: Sun, 10 Mar 2019 12:58:52 -0400 Subject: [PATCH] Disallow NaN as a value for floating-point GUCs. None of the code that uses GUC values is really prepared for them to hold NaN, but parse_real() didn't have any defense against accepting such a value. Treat it the same as a syntax error. I haven't attempted to analyze the exact consequences of setting any of the float GUCs to NaN, but since they're quite unlikely to be good, this seems like a back-patchable bug fix. Note: we don't need an explicit test for +-Infinity because those will be rejected by existing range checks. I added a regression test for that in HEAD, but not older branches because the spelling of the value in the error message will be platform-dependent in branches where we don't always use port/snprintf.c. Discussion: https://postgr.es/m/1798.1552165479@sss.pgh.pa.us --- src/backend/utils/misc/guc.c | 4 ++++ src/test/regress/expected/guc.out | 5 +++++ src/test/regress/sql/guc.sql | 4 ++++ 3 files changed, 13 insertions(+) diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index 4298a0dde23..628cc681dc4 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -5613,6 +5613,10 @@ parse_real(const char *value, double *result) if (endptr == value || errno == ERANGE) return false; + /* reject NaN (infinities will fail range checks later) */ + if (isnan(val)) + return false; + /* allow whitespace after number */ while (isspace((unsigned char) *endptr)) endptr++; diff --git a/src/test/regress/expected/guc.out b/src/test/regress/expected/guc.out index 43ac5f5f11c..4afbd3c4dca 100644 --- a/src/test/regress/expected/guc.out +++ b/src/test/regress/expected/guc.out @@ -506,6 +506,11 @@ SELECT '2006-08-13 12:34:56'::timestamptz; Sun Aug 13 12:34:56 2006 PDT (1 row) +-- Test some simple error cases +SET seq_page_cost TO 'NaN'; +ERROR: parameter "seq_page_cost" requires a numeric value +SET vacuum_cost_delay TO '10s'; +ERROR: 10000 is outside the valid range for parameter "vacuum_cost_delay" (0 .. 100) -- -- Test DISCARD TEMP -- diff --git a/src/test/regress/sql/guc.sql b/src/test/regress/sql/guc.sql index 23e50297800..fa6a9d6c340 100644 --- a/src/test/regress/sql/guc.sql +++ b/src/test/regress/sql/guc.sql @@ -144,6 +144,10 @@ RESET datestyle; SHOW datestyle; SELECT '2006-08-13 12:34:56'::timestamptz; +-- Test some simple error cases +SET seq_page_cost TO 'NaN'; +SET vacuum_cost_delay TO '10s'; + -- -- Test DISCARD TEMP --