Subject: Re: kern/35278: veriexec sometimes feeds user va to log(9)
To: None <kern-bug-people@netbsd.org, gnats-admin@netbsd.org,>
From: Elad Efrat <elad@NetBSD.org>
List: netbsd-bugs
Date: 12/23/2006 16:45:02
The following reply was made to PR kern/35278; it has been noted by GNATS.

From: Elad Efrat <elad@NetBSD.org>
To: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
Cc: gnats-bugs@NetBSD.org
Subject: Re: kern/35278: veriexec sometimes feeds user va to log(9)
Date: Sat, 23 Dec 2006 18:42:01 +0200

 YAMAMOTO Takashi wrote:
 >>> after some more thoughts, i remembered that you can't abuse SAVENAME for
 >>> this purpose because filesystems have their own use of SAVENAME.
 >>> (it's what SAVENAME is for)
 >> why? check_exec() already uses it.
 > 
 > it's safe for plain LOOKUPs.
 > 
 >> what will happen if we use it in
 >> sys_unlink() and rename_files() too?
 > 
 > it ends up with double-free because filesystem can set
 > SAVENAME and free pnbuf by itself,
 > 
 >> (it's working okay here)
 > 
 > it can work for some filesystems like ufs.
 
 that sounds very ugly. what filesystems have these semantics?
 
 -e.