From: dtucker <dtucker@openbsd.org>
Date: Fri, 11 Mar 2022 07:29:53 +0000 (+0000)
Subject: Check for underflow as well as overflow when scaling negative numbers.
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=39af7dcca31cab3059a865d66e9ca17a9a2563f7;p=openbsd

Check for underflow as well as overflow when scaling negative numbers.
ok millert@
---

diff --git a/lib/libutil/fmt_scaled.c b/lib/libutil/fmt_scaled.c
index f06c727be51..0b443d4d83a 100644
--- a/lib/libutil/fmt_scaled.c
+++ b/lib/libutil/fmt_scaled.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fmt_scaled.c,v 1.20 2021/06/20 14:08:42 tb Exp $	*/
+/*	$OpenBSD: fmt_scaled.c,v 1.21 2022/03/11 07:29:53 dtucker Exp $	*/
 
 /*
  * Copyright (c) 2001, 2002, 2003 Ian F. Darwin.  All rights reserved.
@@ -185,7 +185,8 @@ scan_scaled(char *scaled, long long *result)
 			/* truncate fpart so it does't overflow.
 			 * then scale fractional part.
 			 */
-			while (fpart >= LLONG_MAX / scale_fact) {
+			while (fpart >= LLONG_MAX / scale_fact ||
+			    fpart <= LLONG_MIN / scale_fact) {
 				fpart /= 10;
 				fract_digits--;
 			}
diff --git a/regress/lib/libutil/fmt_scaled/fmt_test.c b/regress/lib/libutil/fmt_scaled/fmt_test.c
index f35c4451407..308c2ce01fc 100644
--- a/regress/lib/libutil/fmt_scaled/fmt_test.c
+++ b/regress/lib/libutil/fmt_scaled/fmt_test.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: fmt_test.c,v 1.17 2021/06/20 14:09:59 tb Exp $ */
+/* $OpenBSD: fmt_test.c,v 1.18 2022/03/11 07:29:53 dtucker Exp $ */
 
 /*
  * Combined tests for fmt_scaled and scan_scaled.
@@ -188,6 +188,9 @@ struct {					/* the test cases */
 	{ "",		0, 0 },			/* boundary */
 	{ "--1", -1, EINVAL },
 	{ "++42", -1, EINVAL },
+	{ "-.060000000000000000E", -69175290276410818, 0 },
+	{ "-.600000000000000000E", -691752902764108185, 0 },
+	{ "-60000000000000000E", 0, ERANGE },
 	{ "SCALE_OVERFLOW", 0, ERANGE },
 	{ "SCALE_UNDERFLOW", 0, ERANGE },
 	{ "LLONG_MAX_K", (LLONG_MAX / 1024) * 1024, 0 },