kern/39329: [mount] '..' at mountpoint is subject to the permissions of the shadowed dir

[Serge van den Boom]

On Mon, 16 Aug 2010, arundel at FreeBSD.org wrote:
> Synopsis: [mount] '..' at mountpoint is subject to the permissions of
> the shadowed dir
> 
> State-Changed-From-To: open->feedback
> State-Changed-By: arundel
> State-Changed-When: Mon Aug 16 19:09:35 UTC 2010
> State-Changed-Why: 
> Does this issue still exist? I wasn't able to reproduce the problem
> running a recent HEAD checkout (r211163):
> 
> # mkdir /mnt/tmp
> # chown root:wheel /mnt/tmp
> # chmod 700 /mnt/tmp
> # mount -t msdosfs /dev/da0 /mnt/tmp
> # chmod 755 /mnt/tmp
> # ls -lad /mnt/tmp/.*
> drwx------  1 root  wheel  4096 Jan  1  1980 /mnt/tmp/.
> drwxr-xr-x  5 root  wheel   512 Aug 16 21:05 /mnt/tmp/..
> $ ls -lad /mnt/tmp/.*
> ls: /mnt/tmp/.*: Permission denied
> 
> http://www.freebsd.org/cgi/query-pr.cgi?pr=39329

The most recent FreeBSD system I have root access to at the moment has
a FreeBSD 8.0-RELEASE kernel. After asking around, though, it appears
that the original issue still exists on at least r210462.

However, when I use an msdosfs file system, I get the same behaviour as
you did. I can reproduce the original issue using a file system created
like this:
	# dd if=/dev/zero of=/tmp/foo bs=1024 count=1024
	# mdconfig -a -t vnode -f /tmp/foo
	# newfs /dev/md0

Regards,

Serge