selinux lsm IB/core: Implement LSM notification system

Add a generic notificaiton mechanism in the LSM. Interested consumers
can register a callback with the LSM and security modules can produce
events.

Because access to Infiniband QPs are enforced in the setup phase of a
connection security should be enforced again if the policy changes.
Register infiniband devices for policy change notification and check all
QPs on that device when the notification is received.

Add a call to the notification mechanism from SELinux when the AVC
cache changes or setenforce is cleared.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 96e730cc9b81..631eaa9daf65 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -39,6 +39,8 @@
 #include <linux/init.h>
 #include <linux/mutex.h>
 #include <linux/netdevice.h>
+#include <linux/security.h>
+#include <linux/notifier.h>
 #include <rdma/rdma_netlink.h>
 #include <rdma/ib_addr.h>
 #include <rdma/ib_cache.h>
@@ -82,6 +84,14 @@ static LIST_HEAD(client_list);
 static DEFINE_MUTEX(device_mutex);
 static DECLARE_RWSEM(lists_rwsem);
 
+static int ib_security_change(struct notifier_block *nb, unsigned long event,
+			      void *lsm_data);
+static void ib_policy_change_task(struct work_struct *work);
+static DECLARE_WORK(ib_policy_change_work, ib_policy_change_task);
+
+static struct notifier_block ibdev_lsm_nb = {
+	.notifier_call = ib_security_change,
+};
 
 static int ib_device_check_mandatory(struct ib_device *device)
 {
@@ -349,6 +359,40 @@ static int setup_port_pkey_list(struct ib_device *device)
 	return 0;
 }
 
+static void ib_policy_change_task(struct work_struct *work)
+{
+	struct ib_device *dev;
+
+	down_read(&lists_rwsem);
+	list_for_each_entry(dev, &device_list, core_list) {
+		int i;
+
+		for (i = rdma_start_port(dev); i <= rdma_end_port(dev); i++) {
+			u64 sp;
+			int ret = ib_get_cached_subnet_prefix(dev,
+							      i,
+							      &sp);
+
+			WARN_ONCE(ret,
+				  "ib_get_cached_subnet_prefix err: %d, this should never happen here\n",
+				  ret);
+			ib_security_cache_change(dev, i, sp);
+		}
+	}
+	up_read(&lists_rwsem);
+}
+
+static int ib_security_change(struct notifier_block *nb, unsigned long event,
+			      void *lsm_data)
+{
+	if (event != LSM_POLICY_CHANGE)
+		return NOTIFY_DONE;
+
+	schedule_work(&ib_policy_change_work);
+
+	return NOTIFY_OK;
+}
+
 /**
  * ib_register_device - Register an IB device with IB core
  * @device:Device to register
@@ -1115,10 +1159,18 @@ static int __init ib_core_init(void)
 		goto err_sa;
 	}
 
+	ret = register_lsm_notifier(&ibdev_lsm_nb);
+	if (ret) {
+		pr_warn("Couldn't register LSM notifier. ret %d\n", ret);
+		goto err_ibnl_clients;
+	}
+
 	ib_cache_setup();
 
 	return 0;
 
+err_ibnl_clients:
+	ib_remove_ibnl_clients();
 err_sa:
 	ib_sa_cleanup();
 err_mad:
@@ -1138,6 +1190,7 @@ err:
 
 static void __exit ib_core_cleanup(void)
 {
+	unregister_lsm_notifier(&ibdev_lsm_nb);
 	ib_cache_cleanup();
 	ib_remove_ibnl_clients();
 	ib_sa_cleanup();