[src/trunk]: src/lib/libukfs Give rump_sys_unmount() in ukfs_release() a curl...

[pooka <pooka%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/f30e9042a2eb
branches:  trunk
changeset: 747721:f30e9042a2eb
user:      pooka <pooka%NetBSD.org@localhost>
date:      Tue Sep 29 11:17:00 2009 +0000

description:
Give rump_sys_unmount() in ukfs_release() a curlwp context.  This
prevents use-after-free and should fix crashy cases reported by
Arnaud Ysmal.

diffstat:

 lib/libukfs/ukfs.c |  4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diffs (19 lines):

diff -r 1e53e82e1b36 -r f30e9042a2eb lib/libukfs/ukfs.c
--- a/lib/libukfs/ukfs.c        Tue Sep 29 11:01:39 2009 +0000
+++ b/lib/libukfs/ukfs.c        Tue Sep 29 11:17:00 2009 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ukfs.c,v 1.35 2009/08/04 12:37:14 pooka Exp $  */
+/*     $NetBSD: ukfs.c,v 1.36 2009/09/29 11:17:00 pooka Exp $  */
 
 /*
  * Copyright (c) 2007, 2008  Antti Kantee.  All Rights Reserved.
@@ -308,7 +308,9 @@
                mntflag = 0;
                if (flags & UKFS_RELFLAG_FORCE)
                        mntflag = MNT_FORCE;
+               rump_setup_curlwp(nextpid(fs), 1, 1);
                rv = rump_sys_unmount(fs->ukfs_mountpath, mntflag);
+               rump_clear_curlwp();
                if (rv) {
                        ukfs_chdir(fs, fs->ukfs_mountpath);
                        errno = rv;