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 <[e-mail]>
Acked-by: Doug Ledford <[e-mail]>
[PM: remove the LSM hook init code]
Signed-off-by: Paul Moore <[e-mail]>

drivers/infiniband/core/core_priv.h

···
 #include <linux/cgroup_rdma.h>
 
 #include <rdma/ib_verbs.h>
+#include <rdma/ib_mad.h>
+#include "mad_priv.h"
 
 struct pkey_index_qp_list {
 	struct list_head    pkey_index_list;
···
 				u64              *sn_pfx);
 
 #ifdef CONFIG_SECURITY_INFINIBAND
+int ib_security_pkey_access(struct ib_device *dev,
+			    u8 port_num,
+			    u16 pkey_index,
+			    void *sec);
+
 void ib_security_destroy_port_pkey_list(struct ib_device *device);
 
 void ib_security_cache_change(struct ib_device *device,
···
 void ib_destroy_qp_security_end(struct ib_qp_security *sec);
 int ib_open_shared_qp_security(struct ib_qp *qp, struct ib_device *dev);
 void ib_close_shared_qp_security(struct ib_qp_security *sec);
+int ib_mad_agent_security_setup(struct ib_mad_agent *agent,
+				enum ib_qp_type qp_type);
+void ib_mad_agent_security_cleanup(struct ib_mad_agent *agent);
+int ib_mad_enforce_security(struct ib_mad_agent_private *map, u16 pkey_index);
 #else
+static inline int ib_security_pkey_access(struct ib_device *dev,
+					  u8 port_num,
+					  u16 pkey_index,
+					  void *sec)
+{
+	return 0;
+}
+
 static inline void ib_security_destroy_port_pkey_list(struct ib_device *device)
 {
 }
···
 
 static inline void ib_close_shared_qp_security(struct ib_qp_security *sec)
 {
+}
+
+static inline int ib_mad_agent_security_setup(struct ib_mad_agent *agent,
+					      enum ib_qp_type qp_type)
+{
+	return 0;
+}
+
+static inline void ib_mad_agent_security_cleanup(struct ib_mad_agent *agent)
+{
+}
+
+static inline int ib_mad_enforce_security(struct ib_mad_agent_private *map,
+					  u16 pkey_index)
+{
+	return 0;
 }
 #endif
 #endif /* _CORE_PRIV_H */

drivers/infiniband/core/mad.c

···
 #include <linux/dma-mapping.h>
 #include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/security.h>
 #include <rdma/ib_cache.h>
 
 #include "mad_priv.h"
+#include "core_priv.h"
 #include "mad_rmpp.h"
 #include "smi.h"
 #include "opa_smi.h"
···
 	atomic_set(&mad_agent_priv->refcount, 1);
 	init_completion(&mad_agent_priv->comp);
 
+	ret2 = ib_mad_agent_security_setup(&mad_agent_priv->agent, qp_type);
+	if (ret2) {
+		ret = ERR_PTR(ret2);
+		goto error4;
+	}
+
 	spin_lock_irqsave(&port_priv->reg_lock, flags);
 	mad_agent_priv->agent.hi_tid = ++ib_mad_client_id;
 
···
 				if (method) {
 					if (method_in_use(&method,
 							   mad_reg_req))
-						goto error4;
+						goto error5;
 				}
 			}
 			ret2 = add_nonoui_reg_req(mad_reg_req, mad_agent_priv,
···
 					if (is_vendor_method_in_use(
 							vendor_class,
 							mad_reg_req))
-						goto error4;
+						goto error5;
 				}
 			}
 			ret2 = add_oui_reg_req(mad_reg_req, mad_agent_priv);
 		}
 		if (ret2) {
 			ret = ERR_PTR(ret2);
-			goto error4;
+			goto error5;
 		}
 	}
 
···
 	spin_unlock_irqrestore(&port_priv->reg_lock, flags);
 
 	return &mad_agent_priv->agent;
-
-error4:
+error5:
 	spin_unlock_irqrestore(&port_priv->reg_lock, flags);
+	ib_mad_agent_security_cleanup(&mad_agent_priv->agent);
+error4:
 	kfree(reg_req);
 error3:
 	kfree(mad_agent_priv);
···
 	struct ib_mad_agent *ret;
 	struct ib_mad_snoop_private *mad_snoop_priv;
 	int qpn;
+	int err;
 
 	/* Validate parameters */
 	if ((is_snooping_sends(mad_snoop_flags) && !snoop_handler) ||
···
 	mad_snoop_priv->agent.port_num = port_num;
 	mad_snoop_priv->mad_snoop_flags = mad_snoop_flags;
 	init_completion(&mad_snoop_priv->comp);
+
+	err = ib_mad_agent_security_setup(&mad_snoop_priv->agent, qp_type);
+	if (err) {
+		ret = ERR_PTR(err);
+		goto error2;
+	}
+
 	mad_snoop_priv->snoop_index = register_snoop_agent(
 						&port_priv->qp_info[qpn],
 						mad_snoop_priv);
 	if (mad_snoop_priv->snoop_index < 0) {
 		ret = ERR_PTR(mad_snoop_priv->snoop_index);
-		goto error2;
+		goto error3;
 	}
 
 	atomic_set(&mad_snoop_priv->refcount, 1);
 	return &mad_snoop_priv->agent;
-
+error3:
+	ib_mad_agent_security_cleanup(&mad_snoop_priv->agent);
 error2:
 	kfree(mad_snoop_priv);
 error1:
···
 	deref_mad_agent(mad_agent_priv);
 	wait_for_completion(&mad_agent_priv->comp);
 
+	ib_mad_agent_security_cleanup(&mad_agent_priv->agent);
+
 	kfree(mad_agent_priv->reg_req);
 	kfree(mad_agent_priv);
 }
···
 
 	deref_snoop_agent(mad_snoop_priv);
 	wait_for_completion(&mad_snoop_priv->comp);
+
+	ib_mad_agent_security_cleanup(&mad_snoop_priv->agent);
 
 	kfree(mad_snoop_priv);
 }
···
 
 	/* Walk list of send WRs and post each on send list */
 	for (; send_buf; send_buf = next_send_buf) {
-
 		mad_send_wr = container_of(send_buf,
 					   struct ib_mad_send_wr_private,
 					   send_buf);
 		mad_agent_priv = mad_send_wr->mad_agent_priv;
+
+		ret = ib_mad_enforce_security(mad_agent_priv,
+					      mad_send_wr->send_wr.pkey_index);
+		if (ret)
+			goto error;
 
 		if (!send_buf->mad_agent->send_handler ||
 		    (send_buf->timeout_ms &&
···
 	struct ib_mad_send_wr_private *mad_send_wr;
 	struct ib_mad_send_wc mad_send_wc;
 	unsigned long flags;
+	int ret;
+
+	ret = ib_mad_enforce_security(mad_agent_priv,
+				      mad_recv_wc->wc->pkey_index);
+	if (ret) {
+		ib_free_recv_mad(mad_recv_wc);
+		deref_mad_agent(mad_agent_priv);
+	}
 
 	INIT_LIST_HEAD(&mad_recv_wc->rmpp_list);
 	list_add(&mad_recv_wc->recv_buf.list, &mad_recv_wc->rmpp_list);
···
 						   mad_recv_wc);
 		deref_mad_agent(mad_agent_priv);
 	}
+
+	return;
 }
 
 static enum smi_action handle_ib_smi(const struct ib_mad_port_private *port_priv,

drivers/infiniband/core/security.c

···
 #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)
 {
···
 	return ret;
 }
 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 */

include/linux/lsm_hooks.h

···
  *	@subnet_prefix the subnet prefix of the port being used.
  *	@pkey the pkey to be accessed.
  *	@sec pointer to a security structure.
+ * @ib_endport_manage_subnet:
+ *	Check permissions to send and receive SMPs on a end port.
+ *	@dev_name the IB device name (i.e. mlx4_0).
+ *	@port_num the port number.
+ *	@sec pointer to a security structure.
  * @ib_alloc_security:
  *	Allocate a security structure for Infiniband objects.
  *	@sec pointer to a security structure pointer.
···
 
 #ifdef CONFIG_SECURITY_INFINIBAND
 	int (*ib_pkey_access)(void *sec, u64 subnet_prefix, u16 pkey);
+	int (*ib_endport_manage_subnet)(void *sec, const char *dev_name,
+					u8 port_num);
 	int (*ib_alloc_security)(void **sec);
 	void (*ib_free_security)(void *sec);
 #endif	/* CONFIG_SECURITY_INFINIBAND */
···
 #endif	/* CONFIG_SECURITY_NETWORK */
 #ifdef CONFIG_SECURITY_INFINIBAND
 	struct list_head ib_pkey_access;
+	struct list_head ib_endport_manage_subnet;
 	struct list_head ib_alloc_security;
 	struct list_head ib_free_security;
 #endif	/* CONFIG_SECURITY_INFINIBAND */

include/linux/security.h

···
 
 #ifdef CONFIG_SECURITY_INFINIBAND
 int security_ib_pkey_access(void *sec, u64 subnet_prefix, u16 pkey);
+int security_ib_endport_manage_subnet(void *sec, const char *name, u8 port_num);
 int security_ib_alloc_security(void **sec);
 void security_ib_free_security(void *sec);
 #else	/* CONFIG_SECURITY_INFINIBAND */
 static inline int security_ib_pkey_access(void *sec, u64 subnet_prefix, u16 pkey)
+{
+	return 0;
+}
+
+static inline int security_ib_endport_manage_subnet(void *sec, const char *dev_name, u8 port_num)
 {
 	return 0;
 }

include/rdma/ib_mad.h

···
 	u32			flags;
 	u8			port_num;
 	u8			rmpp_version;
+	void			*security;
+	bool			smp_allowed;
+	bool			lsm_nb_reg;
+	struct notifier_block   lsm_nb;
 };
 
 /**

security/security.c

···
 }
 EXPORT_SYMBOL(security_ib_pkey_access);
 
+int security_ib_endport_manage_subnet(void *sec, const char *dev_name, u8 port_num)
+{
+	return call_int_hook(ib_endport_manage_subnet, 0, sec, dev_name, port_num);
+}
+EXPORT_SYMBOL(security_ib_endport_manage_subnet);
+
 int security_ib_alloc_security(void **sec)
 {
 	return call_int_hook(ib_alloc_security, 0, sec);