kern/43615: kauth usage in tmpfs_lookup less than clear

[pooka%iki.fi@localhost]

>Number:         43615
>Category:       kern
>Synopsis:       kauth usage in tmpfs_lookup less than clear
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Jul 14 15:15:00 +0000 2010
>Originator:     Antti Kantee
>Release:        
>Organization:
>Environment:
>Description:
kauth_authorize_vnode() uses *vpp before tmpfs_alloc_vp()
in tmpfs_lookup().

I'm also unsure why the distinction between dvp and vp
is irrelevant to kauth_authorize_vnode() (cf. VOP_ACCESS)
and why DELETE/RENAME branches should care about the
distinction enough to do it both ways.
>How-To-Repeat:
Go into fnord?-mode when reading tmpfs_lookup.  When it starts making
sense (???), notice a lot of weird things.
>Fix: