From: Laura Abbott <labbott@redhat.com>

commit 08925c2f124f1bac6152a8b234268f9874fc70a5 upstream.

Currently, when updating section permissions to mark areas RO
or NX, the only mm updated is current->mm. This is working off
the assumption that there are no additional mm structures at
the time. This may not always hold true. (Example: calling
modprobe early will trigger a fork/exec). Ensure all mm structres
get updated with the new section information.