[PATCH] chdir(".") can raise SIGSEGV

[Ognyan Kulev]

Hi,

`_hurd_change_directory_port_from_name' in `libc/hurd/hurdchdir.c' tests 
if the given name ends with `/.'.  But with the current code if "." is 
given and this string starts exactly at page boundary and the previous 
page is not vm_allocated then SIGSEGV will be raised.

Regards
--
Ognyan Kulev <ogi@fmi.uni-sofia.bg>, "\"Programmer\""

2002-03-25  Ognyan Kulev <ogi@fmi.uni-sofia.bg>

         * hurdchdir.c (_hurd_change_directory_port_from_name): Don't
         test if NAME ends with "/." if strlen(NAME) < 2.

--- hurdchdir.c.orig    Sun Apr  1 08:04:05 2001
+++ hurdchdir.c Mon Mar 25 15:46:53 2002
@@ -36,7 +36,7 @@ _hurd_change_directory_port_from_name (s
   /* Append trailing "/." to directory name to force ENOTDIR if it's not a
      directory and EACCES if we don't have search permission.  */
   len = strlen (name);
-  if (name[len - 2] == '/' && name[len - 1] == '.')
+  if (len >= 2 && name[len - 2] == '/' && name[len - 1] == '.')
     lookup = name;
   else
     {