(main): Check for overflow in tabstop values

specified via the obsolete form.  E.g., now this command fails:
_POSIX2_VERSION=1 ./expand -$(echo '2^64+1'|bc)
Before it would act like `_POSIX2_VERSION=1 ./expand -1'.

diff --git a/src/expand.c b/src/expand.c
index e3584601a3736528324420eefe2587471ee14cf9..5ea16c07e875dcdae4885b712057579c92377564 100644 (file)
--- a/src/expand.c
+++ b/src/expand.c
@@ -1,5 +1,5 @@
 /* expand - convert tabs to spaces
-   Copyright (C) 89, 91, 1995-2004 Free Software Foundation, Inc.
+   Copyright (C) 89, 91, 1995-2005 Free Software Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -420,7 +420,12 @@ main (int argc, char **argv)
              tabval = 0;
              have_tabval = true;
            }
-         tabval = tabval * 10 + c - '0';
+         {
+           uintmax_t new_t = tabval * 10 + c - '0';
+           if (UINTMAX_MAX / 10 < tabval || new_t < tabval * 10)
+             error (EXIT_FAILURE, 0, _("tab stop value is too large"));
+           tabval = new_t;
+         }
          obsolete_tablist = true;
          break;
        }