Detect range errors when using the %s specifier. Previously, LONG_MAX

was rejected as a range error, while any values less than LONG_MIN
were silently substituted with LONG_MIN.  Furthermore, on some
platforms `time_t' has less range than `long' (e.g. alpha), which may
give incorrect results when parsing some strings.

1 files changed, 10 insertions, 3 deletions

diff --git a/lib/libc/stdtime/strptime.c b/lib/libc/stdtime/strptime.c
index f69847a..ddf6b57 100644
--- a/lib/libc/stdtime/strptime.c
+++ b/lib/libc/stdtime/strptime.c
@@ -64,7 +64,7 @@ __FBSDID("$FreeBSD$");
 #include "namespace.h"
 #include <time.h>
 #include <ctype.h>
-#include <limits.h>
+#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <pthread.h>
@@ -444,11 +444,18 @@ label:
 		case 's':
 			{
 			char *cp;
+			int sverrno;
+			long n;
 			time_t t;
 
-			t = strtol(buf, &cp, 10);
-			if (t == LONG_MAX)
+			sverrno = errno;
+			errno = 0;
+			n = strtol(buf, &cp, 10);
+			if (errno == ERANGE || (long)(t = n) != n) {
+				errno = sverrno;
 				return 0;
+			}
+			errno = sverrno;
 			buf = cp;
 			gmtime_r(&t, tm);
 			*GMTp = 1;