From de20b81a038fe1c2060ce28125eec3838de5bdc5 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Thu, 15 Nov 2018 22:59:33 +0100 Subject: mktime: fix EOVERFLOW bug [BZ#23789] * time/mktime.c [!_LIBC && !DEBUG_MKTIME]: Include libc-config.h, not config.h, for __set_errno. (guess_time_tm, __mktime_internal): Set errno to EOVERFLOW on overflow. --- time/mktime.c | 26 +++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) (limited to 'time') diff --git a/time/mktime.c b/time/mktime.c index 00f0dec6b4..106b4eac26 100644 --- a/time/mktime.c +++ b/time/mktime.c @@ -39,7 +39,7 @@ */ #if !defined _LIBC && !DEBUG_MKTIME -# include +# include #endif /* Assume that leap seconds are possible, unless told otherwise. @@ -51,6 +51,7 @@ #include +#include #include #include #include @@ -255,8 +256,9 @@ long_int_avg (long_int a, long_int b) If TP is null, return a value not equal to T; this avoids false matches. YEAR and YDAY must not be so large that multiplying them by three times the number of seconds in a year (or day, respectively) would overflow long_int. - If the returned value would be out of range, yield the minimal or - maximal in-range value, except do not yield a value equal to T. */ + If TP is non-null and the returned value would be out of range, set + errno to EOVERFLOW and yield a minimal or maximal in-range value + that is not equal to T. */ static long_int guess_time_tm (long_int year, long_int yday, int hour, int min, int sec, long_int t, const struct tm *tp) @@ -269,9 +271,10 @@ guess_time_tm (long_int year, long_int yday, int hour, int min, int sec, tp->tm_hour, tp->tm_min, tp->tm_sec); if (! INT_ADD_WRAPV (t, d, &result)) return result; + __set_errno (EOVERFLOW); } - /* Overflow occurred one way or another. Return the nearest result + /* An error occurred, probably overflow. Return the nearest result that is actually in range, except don't report a zero difference if the actual difference is nonzero, as that would cause a false match; and don't oscillate between two values, as that would @@ -344,6 +347,8 @@ ranged_convert (struct tm *(*convert) (const time_t *, struct tm *), Use *OFFSET to keep track of a guess at the offset of the result, compared to what the result would be for UTC without leap seconds. If *OFFSET's guess is correct, only one CONVERT call is needed. + If successful, set *TP to the canonicalized struct tm; + otherwise leave *TP alone, return ((time_t) -1) and set errno. This function is external because it is used also by timegm.c. */ time_t __mktime_internal (struct tm *tp, @@ -435,7 +440,10 @@ __mktime_internal (struct tm *tp, useful than returning -1. */ goto offset_found; else if (--remaining_probes == 0) - return -1; + { + __set_errno (EOVERFLOW); + return -1; + } /* We have a match. Check whether tm.tm_isdst has the requested value, if any. */ @@ -505,8 +513,12 @@ __mktime_internal (struct tm *tp, sec_adjustment -= sec; sec_adjustment += sec_requested; if (INT_ADD_WRAPV (t, sec_adjustment, &t) - || ! (mktime_min <= t && t <= mktime_max) - || ! convert_time (convert, t, &tm)) + || ! (mktime_min <= t && t <= mktime_max)) + { + __set_errno (EOVERFLOW); + return -1; + } + if (! convert_time (convert, t, &tm)) return -1; } -- cgit v1.2.3