UBUNTU: SAUCE: (efi-lockdown) Prohibit PCMCIA CIS storage when the kernel is locked down

BugLink: https://bugs.launchpad.net/bugs/1884159

Prohibit replacement of the PCMCIA Card Information Structure when the
kernel is locked down.
Suggested-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-pcmcia@lists.infradead.org
(backported from commit c5fe6d4762b16204e218f5299d232b9953c4caaa
 git://git.kernel.org/pub/scm/linux/kernel/git/jwboyer/fedora.git)
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/pcmcia/cistpl.c

@@ -1578,6 +1578,9 @@ static ssize_t pccard_store_cis(struct file *filp, struct kobject *kobj,
 	struct pcmcia_socket *s;
 	int error;
 
+	if (secure_modules())
+		return -EPERM;
+
 	s = to_socket(container_of(kobj, struct device, kobj));
 
 	if (off)