Fix bug #10229 - No access check verification on stream files.

https://bugzilla.samba.org/show_bug.cgi?id=10229

We need to check if the requested access mask
could be used to open the underlying file (if
it existed), as we're passing in zero for the
access mask to the base filename.

Signed-off-by: Jeremy Allison <jra@samba.org>

Fix Bug #10235 - CVE-2013-4475: No access check verification on stream files.
https://bugzilla.samba.org/show_bug.cgi?id=10235
WHATSNEW: Add release notes for Samba 3.6.20.

Bug 10235 - CVE-2013-4475: No access check verification on stream files.

Signed-off-by: Karolin Seeger <kseeger@samba.org>
VERSION: Bump version up to 3.6.21.

Signed-off-by: Karolin Seeger <kseeger@samba.org>
(cherry picked from commit c2287276eb6533586ca1eac8b445ac1f93bcee98)