Subject: bin/7713: you can wall while mesg n
To: None <>
From: David Holland <>
List: netbsd-bugs
Date: 06/05/1999 14:27:27
>Number:         7713
>Category:       bin
>Synopsis:       you can wall while you have mesg n
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people (Utility Bug People)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Jun  5 14:20:00 1999
>Originator:     David A. Holland <>
   - David A. Holland             |    VINO project home page:    |
>Release:        NetBSD 1.4

System: NetBSD bordeaux 1.4 NetBSD 1.4 (GENERIC) #0: Fri May 7 12:27:31 PDT 1999 i386

It does not appear to be any different in today's (6/5) current.

	If you mesg n, you can still wall, because wall seems to be
	lacking a check for this. 

	Since you will see your own walls anyway (because your ttys
	are owned by you and thus writable by your wall process), this
	could lead to a good bit of confusion. It is also inconsistent
	with write(1).

	mesg n

	Add check for your own tty being group writable, unless you're
	root (in which case issuing a warning might be useful.) Using
	stderr to get the tty is probably advisable, and if there
	doesn't seem to be a tty it's probably better to let the wall
	go through...

	Will do patch if you like; let me know.