# \[PATCH 18/27\] Prohibit PCMCIA CIS storage when the kernel is locked down

- From: Matthew Garrett \<hidden\>
- Date: 2019-03-07 00:00:17 
- List: linux-security-module
- Page: https://ratatoskr.run/linux-security-module/2019/03/5532070
- Thread: https://ratatoskr.run/linux-security-module/2019/03/5532057/t.md

```text
From: David Howells <dhowells@redhat.com>

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: <redacted>
Signed-off-by: Matthew Garrett <redacted>
---
 drivers/pcmcia/cistpl.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/pcmcia/cistpl.c b/drivers/pcmcia/cistpl.c
index ac0672b8dfca..8adf092d0e18 100644
--- a/drivers/pcmcia/cistpl.c
+++ b/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 (kernel_is_locked_down("Direct PCMCIA CIS storage"))
+		return -EPERM;
+
 	s = to_socket(container_of(kobj, struct device, kobj));
 
 	if (off)
-- 
2.21.0.352.gf09ad66450-goog

```