Re: Serial Port COM1 under Linux on IBM ThinkPad 770X

Alan Cox (alan@lxorguk.ukuu.org.uk)
Fri, 2 Jul 1999 17:25:21 +0100 (BST)


> 0 crw-rw---- 1 root dialout 4, 64 Feb 23 04:42 /dev/ttyS0
> 0 crw-rw---- 1 root dialout 4, 65 Feb 23 04:42 /dev/ttyS1
> root@ibmtop:pts/0 ~ # cu -l /dev/ttyS0
> cu: open (/dev/ttyS0): Permission denied
> cu: /dev/ttyS0: Line in use
> zsh: 5731 exit 1 cu -l /dev/ttyS0
>
> >From strace cu:
> open("/dev/ttyS0", O_RDWR|O_NONBLOCK) = -1 EACCES (Permission denied)
>
> But this is as superuser (root). How is this possible at all?

cu is setuid to uucp on some systems. Unless you have a deep desire to
inflict cu on yourself in the name of tradition try playing with minicom.
If you want to suffer cu then chmod it so its not setuid uucp

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/