Fix off-by-one on specially crafted /etc/shells file.

ok gilles@, millert@

diff --git a/lib/libc/gen/getusershell.c b/lib/libc/gen/getusershell.c
index a46fd02..36af0ee 100644 (file)
--- a/lib/libc/gen/getusershell.c
+++ b/lib/libc/gen/getusershell.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: getusershell.c,v 1.11 2013/11/24 23:51:29 deraadt Exp $ */
+/*     $OpenBSD: getusershell.c,v 1.12 2014/01/17 20:51:54 tobias Exp $ */
 /*
  * Copyright (c) 1985, 1993
  *     The Regents of the University of California.  All rights reserved.
@@ -109,7 +109,7 @@ initshells(void)
                (void)fclose(fp);
                return (okshells);
        }
-       shells = calloc((size_t)(statb.st_size / 3), sizeof (char *));
+       shells = calloc((size_t)(statb.st_size / 3 + 1), sizeof (char *));
        if (shells == NULL) {
                (void)fclose(fp);
                free(strings);