Re: 2.6.10 breaks xconsole

[Lars <lhofhansl@yahoo.com>]

Lars wrote:
> Running kernel 2.6.10, xconsole always displays: Couldn't open console.
> xconsole works fine in the identical setup with 2.6.9 and 2.4.28.
> 
> The permissions are set correctly:
> crw-rw-r--  1 lars tty 5, 1 2004-12-25 13:17 /dev/console
> 
> xconsole won't work when run as either lars, a tty member, and even 
> root. In all cases the message above is shown.
> 
> If I change permission to:
> crw-rw-r--  1 root tty 5, 1 2004-12-25 13:17 /dev/console
> 
> xconsole can at least be run as root.
> 
> I guess this is related to this patch:
> <od@suse.de>
>     [PATCH] TIOCCONS security
> 
> Forcing xconsole to be run as root is not a good idea, IMHO.
> 
> -- Lars
> 
> ps. Please CC me directly as I'm not subscribed to the list.
> 

Fixed it by reversion this portion of the 2.6.10 patch to 
drivers/char/tty_io.c

@@ -1981,10 +2012,10 @@

  static int tioccons(struct file *file)
  {
+       if (!capable(CAP_SYS_ADMIN))
+               return -EPERM;
         if (file->f_op->write == redirected_tty_write) {
                 struct file *f;
-               if (!capable(CAP_SYS_ADMIN))
-                       return -EPERM;
                 spin_lock(&redirect_lock);
                 f = redirect;
                 redirect = NULL;


-- Lars