[GIT PULL] namespace fixes for v4.20-rc2

[Eric W. Biederman]

Linus,

Please pull the for-linus branch from the git tree:

   git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace.git for-linus

   HEAD: 9c8e0a1b683525464a2abe9fb4b54404a50ed2b4 mount: Prevent MNT_DETACH from disconnecting locked mounts

I believe all of these are simple obviously correct bug fixes.  These
fall into two groups.  Fixing the implementation of MNT_LOCKED which
prevents lesser privileged users from seeing unders mounts created by
more privileged users.  Fixing the extended uid and group mapping in
user namespaces.

As well as ensuring the code looks correct I have spot tested these
changes as well and in my testing the fixes are working.

I have let these changes sit on my branch for a few days as well and
none of the automated testing has found any problems either.

Eric W. Biederman (3):
      mount: Retest MNT_LOCKED in do_umount
      mount: Don't allow copying MNT_UNBINDABLE|MNT_LOCKED mounts
      mount: Prevent MNT_DETACH from disconnecting locked mounts

Jann Horn (1):
      userns: also map extents in the reverse map to kernel IDs

 fs/namespace.c          | 22 +++++++++++++++++-----
 kernel/user_namespace.c | 12 ++++++++----
 2 files changed, 25 insertions(+), 9 deletions(-)

Eric