Date: Sat, 3 Apr 2010 06:03:55 GMT From: NARUSE@FreeBSD.org, Yui <naruse@airemix.jp> To: freebsd-gnats-submit@FreeBSD.org Subject: misc/145341: localtime doesn't handle overflow Message-ID: <201004030603.o3363tYR040535@www.freebsd.org> Resent-Message-ID: <201004030747.o337l9l0097893@freefall.freebsd.org>
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>Number: 145341 >Category: misc >Synopsis: localtime doesn't handle overflow >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Sat Apr 03 07:47:08 UTC 2010 >Closed-Date: >Last-Modified: >Originator: NARUSE, Yui >Release: FreeBSD 8.0-STABLE amd64 >Organization: >Environment: FreeBSD windy.airemix.net 8.0-STABLE FreeBSD 8.0-STABLE #9: Fri Feb 26 20:47:20 JST 2010 root@windy.airemix.net:/usr/obj/usr/src/sys/GENERIC amd64 >Description: gmtime, gmtime_r, localtime and localtime_r may overflow when the value of year is beyond signed int: year 2147481747 problem. POSIX says, on such overflow gmtime() shall return NULL and set errnor as EOVERFLOW, but FreeBSD 8 doesn't. http://www.opengroup.org/onlinepubs/9699919799/functions/gmtime.html >How-To-Repeat: Run following code: ---------- #include <stdio.h> #include <time.h> #include <errno.h> void t_inspect(time_t t) { struct tm *tp; errno = 0; tp = gmtime(&t); printf("t:%ld, tp: %p errno:%d\n",t,tp,errno); if (tp) printf("sec: %d, min:%d, hour:%d, mday:%d, mon:%d, year:%d,\n" \ "wday:%d, yday:%d, isdst:%d, gmtoff: %ld, zone: %s\n", tp->tm_sec, tp->tm_min, tp->tm_hour, tp->tm_mday, tp->tm_mon, tp->tm_year, tp->tm_wday, tp->tm_yday, tp->tm_isdst, tp->tm_gmtoff, tp->tm_zone); } int main(void) { time_t t = 67767976233532799; t_inspect(t-1); t_inspect(t); t_inspect(t+1); return 0; } ---------- and got following result; second and third output equal. ---------- t:67767976233532798, tp: 0x80099c900 errno:2 sec: 58, min:59, hour:23, mday:31, mon:11, year:2147481747, wday:2, yday:364, isdst:0, gmtoff: 0, zone: UTC t:67767976233532799, tp: 0x80099c900 errno:0 sec: 59, min:59, hour:23, mday:31, mon:11, year:2147481747, wday:2, yday:364, isdst:0, gmtoff: 0, zone: UTC t:67767976233532800, tp: 0x80099c900 errno:0 sec: 59, min:59, hour:23, mday:31, mon:11, year:2147481747, wday:2, yday:364, isdst:0, gmtoff: 0, zone: UTC >Fix: >Release-Note: >Audit-Trail: >Unformatted:
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