>From 4c8309661d861d838e42b2277e0d43b16d62e061 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Tue, 10 Mar 2015 09:37:50 -0700 Subject: [PROPOSED PATCH] Avoid integer overflow in mktime MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit * localtime.c (time2sub), NEWS: Avoid signed arithmetic overflow. (Problem reported by J��rg Richter.) --- NEWS | 5 +++++ localtime.c | 15 ++++----------- 2 files changed, 9 insertions(+), 11 deletions(-) diff --git a/NEWS b/NEWS index 5aca1f6..1e74bfd 100644 --- a/NEWS +++ b/NEWS @@ -29,6 +29,11 @@ Unreleased, experimental changes Correct the 1992-2010 DST abbreviation in Volgograd from "MSK" to "MSD". (Thanks to Hank W.) + Changes affecting code + + Fix integer overflow bug in reference 'mktime' implementation. + (Problem reported by J��rg Richter.) + Changes affecting commentary Cite the recent Mexican decree changing Quintana Roo's time zone. diff --git a/localtime.c b/localtime.c index f44390a..a2d9aa8 100644 --- a/localtime.c +++ b/localtime.c @@ -1783,10 +1783,10 @@ time2sub(struct tm *const tmp, register int dir; register int i, j; register int saved_seconds; - register int_fast32_t li; + register int_fast32_t li; register time_t lo; register time_t hi; - int_fast32_t y; + int_fast32_t y; time_t newt; time_t t; struct tm yourtm, mytm; @@ -1861,15 +1861,8 @@ time2sub(struct tm *const tmp, /* ** Do a binary search (this works whatever time_t's type is). */ - if (!TYPE_SIGNED(time_t)) { - lo = 0; - hi = lo - 1; - } else { - lo = 1; - for (i = 0; i < (int) TYPE_BIT(time_t) - 1; ++i) - lo *= 2; - hi = -(lo + 1); - } + lo = time_t_min; + hi = time_t_max; for ( ; ; ) { t = lo / 2 + hi / 2; if (t < lo) -- 2.1.0