IB/core: Enforce security on management datagrams

Allocate and free a security context when creating and destroying a MAD
agent.  This context is used for controlling access to PKeys and sending
and receiving SMPs.

When sending or receiving a MAD check that the agent has permission to
access the PKey for the Subnet Prefix of the port.

During MAD and snoop agent registration for SMI QPs check that the
calling process has permission to access the manage the subnet  and
register a callback with the LSM to be notified of policy changes. When
notificaiton of a policy change occurs recheck permission and set a flag
indicating sending and receiving SMPs is allowed.

When sending and receiving MADs check that the agent has access to the
SMI if it's on an SMI QP.  Because security policy can change it's
possible permission was allowed when creating the agent, but no longer
is.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Acked-by: Doug Ledford <dledford@redhat.com>
[PM: remove the LSM hook init code]
Signed-off-by: Paul Moore <paul@paul-moore.com>

1 files changed, 92 insertions, 0 deletions

diff --git a/drivers/infiniband/core/security.c b/drivers/infiniband/core/security.c
index b2f170ddc062..3e8c38953912 100644
--- a/drivers/infiniband/core/security.c
+++ b/drivers/infiniband/core/security.c
@@ -39,6 +39,7 @@
 #include <rdma/ib_verbs.h>
 #include <rdma/ib_cache.h>
 #include "core_priv.h"
+#include "mad_priv.h"
 
 static struct pkey_index_qp_list *get_pkey_idx_qp_list(struct ib_port_pkey *pp)
 {
@@ -610,4 +611,95 @@ int ib_security_modify_qp(struct ib_qp *qp,
 }
 EXPORT_SYMBOL(ib_security_modify_qp);
 
+int ib_security_pkey_access(struct ib_device *dev,
+			    u8 port_num,
+			    u16 pkey_index,
+			    void *sec)
+{
+	u64 subnet_prefix;
+	u16 pkey;
+	int ret;
+
+	ret = ib_get_cached_pkey(dev, port_num, pkey_index, &pkey);
+	if (ret)
+		return ret;
+
+	ret = ib_get_cached_subnet_prefix(dev, port_num, &subnet_prefix);
+
+	if (ret)
+		return ret;
+
+	return security_ib_pkey_access(sec, subnet_prefix, pkey);
+}
+EXPORT_SYMBOL(ib_security_pkey_access);
+
+static int ib_mad_agent_security_change(struct notifier_block *nb,
+					unsigned long event,
+					void *data)
+{
+	struct ib_mad_agent *ag = container_of(nb, struct ib_mad_agent, lsm_nb);
+
+	if (event != LSM_POLICY_CHANGE)
+		return NOTIFY_DONE;
+
+	ag->smp_allowed = !security_ib_endport_manage_subnet(ag->security,
+							     ag->device->name,
+							     ag->port_num);
+
+	return NOTIFY_OK;
+}
+
+int ib_mad_agent_security_setup(struct ib_mad_agent *agent,
+				enum ib_qp_type qp_type)
+{
+	int ret;
+
+	ret = security_ib_alloc_security(&agent->security);
+	if (ret)
+		return ret;
+
+	if (qp_type != IB_QPT_SMI)
+		return 0;
+
+	ret = security_ib_endport_manage_subnet(agent->security,
+						agent->device->name,
+						agent->port_num);
+	if (ret)
+		return ret;
+
+	agent->lsm_nb.notifier_call = ib_mad_agent_security_change;
+	ret = register_lsm_notifier(&agent->lsm_nb);
+	if (ret)
+		return ret;
+
+	agent->smp_allowed = true;
+	agent->lsm_nb_reg = true;
+	return 0;
+}
+
+void ib_mad_agent_security_cleanup(struct ib_mad_agent *agent)
+{
+	security_ib_free_security(agent->security);
+	if (agent->lsm_nb_reg)
+		unregister_lsm_notifier(&agent->lsm_nb);
+}
+
+int ib_mad_enforce_security(struct ib_mad_agent_private *map, u16 pkey_index)
+{
+	int ret;
+
+	if (map->agent.qp->qp_type == IB_QPT_SMI && !map->agent.smp_allowed)
+		return -EACCES;
+
+	ret = ib_security_pkey_access(map->agent.device,
+				      map->agent.port_num,
+				      pkey_index,
+				      map->agent.security);
+
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
 #endif /* CONFIG_SECURITY_INFINIBAND */