selinux: Implement Infiniband PKey "Access" access vector

Add a type and access vector for PKeys. Implement the ib_pkey_access
hook to check that the caller has permission to access the PKey on the
given subnet prefix. Add an interface to get the PKey SID. Walk the PKey
ocontexts to find an entry for the given subnet prefix and pkey.

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

4 files changed, 66 insertions, 0 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 062b459b62bf..b59255f86274 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6148,6 +6148,27 @@ static int selinux_key_getsecurity(struct key *key, char **_buffer)
 #endif
 
 #ifdef CONFIG_SECURITY_INFINIBAND
+static int selinux_ib_pkey_access(void *ib_sec, u64 subnet_prefix, u16 pkey_val)
+{
+	struct common_audit_data ad;
+	int err;
+	u32 sid = 0;
+	struct ib_security_struct *sec = ib_sec;
+	struct lsm_ibpkey_audit ibpkey;
+
+	err = security_ib_pkey_sid(subnet_prefix, pkey_val, &sid);
+	if (err)
+		return err;
+
+	ad.type = LSM_AUDIT_DATA_IBPKEY;
+	ibpkey.subnet_prefix = subnet_prefix;
+	ibpkey.pkey = pkey_val;
+	ad.u.ibpkey = &ibpkey;
+	return avc_has_perm(sec->sid, sid,
+			    SECCLASS_INFINIBAND_PKEY,
+			    INFINIBAND_PKEY__ACCESS, &ad);
+}
+
 static int selinux_ib_alloc_security(void **ib_sec)
 {
 	struct ib_security_struct *sec;
@@ -6352,6 +6373,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(tun_dev_attach, selinux_tun_dev_attach),
 	LSM_HOOK_INIT(tun_dev_open, selinux_tun_dev_open),
 #ifdef CONFIG_SECURITY_INFINIBAND
+	LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access),
 	LSM_HOOK_INIT(ib_alloc_security, selinux_ib_alloc_security),
 	LSM_HOOK_INIT(ib_free_security, selinux_ib_free_security),
 #endif
diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h
index 3e49a78f1f46..0fec1c505f84 100644
--- a/security/selinux/include/classmap.h
+++ b/security/selinux/include/classmap.h
@@ -231,6 +231,8 @@ struct security_class_mapping secclass_map[] = {
 	  { COMMON_SOCK_PERMS, NULL } },
 	{ "smc_socket",
 	  { COMMON_SOCK_PERMS, NULL } },
+	{ "infiniband_pkey",
+	  { "access", NULL } },
 	{ NULL }
   };
 
diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h
index b48a462cf446..592c014e369c 100644
--- a/security/selinux/include/security.h
+++ b/security/selinux/include/security.h
@@ -181,6 +181,8 @@ int security_get_user_sids(u32 callsid, char *username,
 
 int security_port_sid(u8 protocol, u16 port, u32 *out_sid);
 
+int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid);
+
 int security_netif_sid(char *name, u32 *if_sid);
 
 int security_node_sid(u16 domain, void *addr, u32 addrlen,
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 2dccba4851f8..02257d90adc9 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -2233,6 +2233,46 @@ out:
 }
 
 /**
+ * security_pkey_sid - Obtain the SID for a pkey.
+ * @subnet_prefix: Subnet Prefix
+ * @pkey_num: pkey number
+ * @out_sid: security identifier
+ */
+int security_ib_pkey_sid(u64 subnet_prefix, u16 pkey_num, u32 *out_sid)
+{
+	struct ocontext *c;
+	int rc = 0;
+
+	read_lock(&policy_rwlock);
+
+	c = policydb.ocontexts[OCON_IBPKEY];
+	while (c) {
+		if (c->u.ibpkey.low_pkey <= pkey_num &&
+		    c->u.ibpkey.high_pkey >= pkey_num &&
+		    c->u.ibpkey.subnet_prefix == subnet_prefix)
+			break;
+
+		c = c->next;
+	}
+
+	if (c) {
+		if (!c->sid[0]) {
+			rc = sidtab_context_to_sid(&sidtab,
+						   &c->context[0],
+						   &c->sid[0]);
+			if (rc)
+				goto out;
+		}
+		*out_sid = c->sid[0];
+	} else
+		*out_sid = SECINITSID_UNLABELED;
+
+out:
+	read_unlock(&policy_rwlock);
+	return rc;
+}
+
+/**
  * security_netif_sid - Obtain the SID for a network interface.
  * @name: interface name
  * @if_sid: interface SID