From: J William Piggott <elseifthen@gmx.com>
Date: Tue, 26 Sep 2017 00:56:06 +0000 (-0400)
Subject: lib/timeutils: ISO_8601_BUFSIZ too small
X-Git-Tag: v2.31.1~34
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=a62e5dacff4fa8c9f634680e6989a2fde31b71db;p=thirdparty%2Futil-linux.git

lib/timeutils: ISO_8601_BUFSIZ too small

Although iso-8601 specifies years as 4 digits, it allows
them to be wider.

The current POSIX year width is limited by 'int tm_year'
at 10 digits plus a negative sign.

That, and the possibility of nanosecond time makes the
widest POSIX iso-8601 time 41 characters. Plus the \0
string terminator yields a buffer size of 42.

Before truncated output:
/sbin/hwclock --utc --noadjfile --predict --date '-2147483765 years'
-2147481748-09-25 20:29:45.0000

Patched:
./hwclock --utc --noadjfile --predict --date '-2147483765 years'
-2147481748-09-25 20:17:21.000000-0456

./hwclock --utc --noadjfile --predict --date '-2147483766 years'
hwclock: invalid date '-2147483766 years'

Comparable to coreutils 'date' command:
date -Ins --date '-2147483765 years'
-2147481748-09-25T19:49:31,578899297-0456

date -Ins --date '-2147483766 years'
date: invalid date '-2147483766 years'

The 'date' output illustrates the full 41 character POSIX iso-8601

Signed-off-by: J William Piggott <elseifthen@gmx.com>
---

diff --git a/include/timeutils.h b/include/timeutils.h
index 874f853b76..edd42f7fe8 100644
--- a/include/timeutils.h
+++ b/include/timeutils.h
@@ -65,7 +65,7 @@ enum {
 	ISO_8601_GMTIME		= (1 << 7)
 };
 
-#define ISO_8601_BUFSIZ	32
+#define ISO_8601_BUFSIZ	42
 
 int strtimeval_iso(struct timeval *tv, int flags, char *buf, size_t bufsz);
 int strtm_iso(struct tm *tm, int flags, char *buf, size_t bufsz);