bonding: Display LACP info only to CAP_NET_ADMIN capable user

Actor and Partner details can be accessed via proc-fs, sys-fs
entries or netlink interface. These interfaces are world readable
at this moment. The earlier patch-series made the LACP communication
secure to avoid nuisance attack from within the same L2 domain but
it did not prevent "someone unprivileged" looking at that information
on host and perform the same act.

This patch essentially avoids spitting those entries if the user
in question does not have enough privileges.

Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Signed-off-by: Andy Gospodarek <gospo@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 53 insertions, 48 deletions

diff --git a/drivers/net/bonding/bond_procfs.c b/drivers/net/bonding/bond_procfs.c
index e7f3047a26df..f514fe5e80a5 100644
--- a/drivers/net/bonding/bond_procfs.c
+++ b/drivers/net/bonding/bond_procfs.c
@@ -135,27 +135,30 @@ static void bond_info_show_master(struct seq_file *seq)
 					  bond->params.ad_select);
 		seq_printf(seq, "Aggregator selection policy (ad_select): %s\n",
 			   optval->string);
-		seq_printf(seq, "System priority: %d\n",
-			   BOND_AD_INFO(bond).system.sys_priority);
-		seq_printf(seq, "System MAC address: %pM\n",
-			   &BOND_AD_INFO(bond).system.sys_mac_addr);
-
-		if (__bond_3ad_get_active_agg_info(bond, &ad_info)) {
-			seq_printf(seq, "bond %s has no active aggregator\n",
-				   bond->dev->name);
-		} else {
-			seq_printf(seq, "Active Aggregator Info:\n");
-
-			seq_printf(seq, "\tAggregator ID: %d\n",
-				   ad_info.aggregator_id);
-			seq_printf(seq, "\tNumber of ports: %d\n",
-				   ad_info.ports);
-			seq_printf(seq, "\tActor Key: %d\n",
-				   ad_info.actor_key);
-			seq_printf(seq, "\tPartner Key: %d\n",
-				   ad_info.partner_key);
-			seq_printf(seq, "\tPartner Mac Address: %pM\n",
-				   ad_info.partner_system);
+		if (capable(CAP_NET_ADMIN)) {
+			seq_printf(seq, "System priority: %d\n",
+				   BOND_AD_INFO(bond).system.sys_priority);
+			seq_printf(seq, "System MAC address: %pM\n",
+				   &BOND_AD_INFO(bond).system.sys_mac_addr);
+
+			if (__bond_3ad_get_active_agg_info(bond, &ad_info)) {
+				seq_printf(seq,
+					   "bond %s has no active aggregator\n",
+					   bond->dev->name);
+			} else {
+				seq_printf(seq, "Active Aggregator Info:\n");
+
+				seq_printf(seq, "\tAggregator ID: %d\n",
+					   ad_info.aggregator_id);
+				seq_printf(seq, "\tNumber of ports: %d\n",
+					   ad_info.ports);
+				seq_printf(seq, "\tActor Key: %d\n",
+					   ad_info.actor_key);
+				seq_printf(seq, "\tPartner Key: %d\n",
+					   ad_info.partner_key);
+				seq_printf(seq, "\tPartner Mac Address: %pM\n",
+					   ad_info.partner_system);
+			}
 		}
 	}
 }
@@ -199,33 +202,35 @@ static void bond_info_show_slave(struct seq_file *seq,
 			seq_printf(seq, "Partner Churned Count: %d\n",
 				   port->churn_partner_count);
 
-			seq_puts(seq, "details actor lacp pdu:\n");
-			seq_printf(seq, "    system priority: %d\n",
-				   port->actor_system_priority);
-			seq_printf(seq, "    system mac address: %pM\n",
-				   &port->actor_system);
-			seq_printf(seq, "    port key: %d\n",
-				   port->actor_oper_port_key);
-			seq_printf(seq, "    port priority: %d\n",
-				   port->actor_port_priority);
-			seq_printf(seq, "    port number: %d\n",
-				   port->actor_port_number);
-			seq_printf(seq, "    port state: %d\n",
-				   port->actor_oper_port_state);
-
-			seq_puts(seq, "details partner lacp pdu:\n");
-			seq_printf(seq, "    system priority: %d\n",
-				   port->partner_oper.system_priority);
-			seq_printf(seq, "    system mac address: %pM\n",
-				   &port->partner_oper.system);
-			seq_printf(seq, "    oper key: %d\n",
-				   port->partner_oper.key);
-			seq_printf(seq, "    port priority: %d\n",
-				   port->partner_oper.port_priority);
-			seq_printf(seq, "    port number: %d\n",
-				   port->partner_oper.port_number);
-			seq_printf(seq, "    port state: %d\n",
-				   port->partner_oper.port_state);
+			if (capable(CAP_NET_ADMIN)) {
+				seq_puts(seq, "details actor lacp pdu:\n");
+				seq_printf(seq, "    system priority: %d\n",
+					   port->actor_system_priority);
+				seq_printf(seq, "    system mac address: %pM\n",
+					   &port->actor_system);
+				seq_printf(seq, "    port key: %d\n",
+					   port->actor_oper_port_key);
+				seq_printf(seq, "    port priority: %d\n",
+					   port->actor_port_priority);
+				seq_printf(seq, "    port number: %d\n",
+					   port->actor_port_number);
+				seq_printf(seq, "    port state: %d\n",
+					   port->actor_oper_port_state);
+
+				seq_puts(seq, "details partner lacp pdu:\n");
+				seq_printf(seq, "    system priority: %d\n",
+					   port->partner_oper.system_priority);
+				seq_printf(seq, "    system mac address: %pM\n",
+					   &port->partner_oper.system);
+				seq_printf(seq, "    oper key: %d\n",
+					   port->partner_oper.key);
+				seq_printf(seq, "    port priority: %d\n",
+					   port->partner_oper.port_priority);
+				seq_printf(seq, "    port number: %d\n",
+					   port->partner_oper.port_number);
+				seq_printf(seq, "    port state: %d\n",
+					   port->partner_oper.port_state);
+			}
 		} else {
 			seq_puts(seq, "Aggregator ID: N/A\n");
 		}