log: handle integer overflow in timestamps

diff --git a/date.c b/date.c
index 1fdcf7c6eae0386552c5d7e069f5242fca3c2e0e..2dae471dd124006a66b7fcdab97e61fdc792a30e 100644 (file)
--- a/date.c
+++ b/date.c
@@ -624,7 +624,7 @@ static int match_object_header_date(const char *date, unsigned long *timestamp,
        unsigned long stamp;
        int ofs;
 
-       if (*date < '0' || '9' <= *date)
+       if (*date < '0' || '9' < *date)
                return -1;
        stamp = strtoul(date, &end, 10);
        if (*end != ' ' || stamp == ULONG_MAX || (end[1] != '+' && end[1] != '-'))
@@ -1085,3 +1085,20 @@ unsigned long approxidate_careful(const char *date, int *error_ret)
        gettimeofday(&tv, NULL);
        return approxidate_str(date, &tv, error_ret);
 }
+
+int date_overflows(unsigned long t)
+{
+       time_t sys;
+
+       /* If we overflowed our unsigned long, that's bad... */
+       if (t == ULONG_MAX)
+               return 1;
+
+       /*
+        * ...but we also are going to feed the result to system
+        * functions that expect time_t, which is often "signed long".
+        * Make sure that we fit into time_t, as well.
+        */
+       sys = t;
+       return t != sys || (t < 1) != (sys < 1);
+}