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>

drivers/net/bonding/bond_netlink.c

@@ -601,6 +601,7 @@ static int bond_fill_info(struct sk_buff *skb,
 	if (BOND_MODE(bond) == BOND_MODE_8023AD) {
 		struct ad_info info;
 
+		if (capable(CAP_NET_ADMIN)) {
 			if (nla_put_u16(skb, IFLA_BOND_AD_ACTOR_SYS_PRIO,
 					bond->params.ad_actor_sys_prio))
 				goto nla_put_failure;
@@ -613,7 +614,7 @@ static int bond_fill_info(struct sk_buff *skb,
 				    sizeof(bond->params.ad_actor_system),
 				    &bond->params.ad_actor_system))
 				goto nla_put_failure;
-
+		}
 		if (!bond_3ad_get_active_agg_info(bond, &info)) {
 			struct nlattr *nest;
 

drivers/net/bonding/bond_procfs.c

@@ -135,13 +135,15 @@ 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);
+		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",
+				seq_printf(seq,
+					   "bond %s has no active aggregator\n",
 					   bond->dev->name);
 			} else {
 				seq_printf(seq, "Active Aggregator Info:\n");
@@ -158,6 +160,7 @@ static void bond_info_show_master(struct seq_file *seq)
 					   ad_info.partner_system);
 			}
 		}
+	}
 }
 
 static void bond_info_show_slave(struct seq_file *seq,
@@ -199,6 +202,7 @@ static void bond_info_show_slave(struct seq_file *seq,
 			seq_printf(seq, "Partner Churned Count: %d\n",
 				   port->churn_partner_count);
 
+			if (capable(CAP_NET_ADMIN)) {
 				seq_puts(seq, "details actor lacp pdu:\n");
 				seq_printf(seq, "    system priority: %d\n",
 					   port->actor_system_priority);
@@ -226,6 +230,7 @@ static void bond_info_show_slave(struct seq_file *seq,
 					   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");
 		}

drivers/net/bonding/bond_sysfs.c

@@ -549,7 +549,7 @@ static ssize_t bonding_show_ad_actor_key(struct device *d,
 	int count = 0;
 	struct bonding *bond = to_bond(d);
 
-	if (BOND_MODE(bond) == BOND_MODE_8023AD) {
+	if (BOND_MODE(bond) == BOND_MODE_8023AD && capable(CAP_NET_ADMIN)) {
 		struct ad_info ad_info;
 		count = sprintf(buf, "%d\n",
 				bond_3ad_get_active_agg_info(bond, &ad_info)
@@ -569,7 +569,7 @@ static ssize_t bonding_show_ad_partner_key(struct device *d,
 	int count = 0;
 	struct bonding *bond = to_bond(d);
 
-	if (BOND_MODE(bond) == BOND_MODE_8023AD) {
+	if (BOND_MODE(bond) == BOND_MODE_8023AD && capable(CAP_NET_ADMIN)) {
 		struct ad_info ad_info;
 		count = sprintf(buf, "%d\n",
 				bond_3ad_get_active_agg_info(bond, &ad_info)
@@ -589,7 +589,7 @@ static ssize_t bonding_show_ad_partner_mac(struct device *d,
 	int count = 0;
 	struct bonding *bond = to_bond(d);
 
-	if (BOND_MODE(bond) == BOND_MODE_8023AD) {
+	if (BOND_MODE(bond) == BOND_MODE_8023AD && capable(CAP_NET_ADMIN)) {
 		struct ad_info ad_info;
 		if (!bond_3ad_get_active_agg_info(bond, &ad_info))
 			count = sprintf(buf, "%pM\n", ad_info.partner_system);
@@ -698,7 +698,7 @@ static ssize_t bonding_show_ad_actor_sys_prio(struct device *d,
 {
 	struct bonding *bond = to_bond(d);
 
-	if (BOND_MODE(bond) == BOND_MODE_8023AD)
+	if (BOND_MODE(bond) == BOND_MODE_8023AD && capable(CAP_NET_ADMIN))
 		return sprintf(buf, "%hu\n", bond->params.ad_actor_sys_prio);
 
 	return 0;
@@ -712,7 +712,7 @@ static ssize_t bonding_show_ad_actor_system(struct device *d,
 {
 	struct bonding *bond = to_bond(d);
 
-	if (BOND_MODE(bond) == BOND_MODE_8023AD)
+	if (BOND_MODE(bond) == BOND_MODE_8023AD && capable(CAP_NET_ADMIN))
 		return sprintf(buf, "%pM\n", bond->params.ad_actor_system);
 
 	return 0;
@@ -727,7 +727,7 @@ static ssize_t bonding_show_ad_user_port_key(struct device *d,
 {
 	struct bonding *bond = to_bond(d);
 
-	if (BOND_MODE(bond) == BOND_MODE_8023AD)
+	if (BOND_MODE(bond) == BOND_MODE_8023AD && capable(CAP_NET_ADMIN))
 		return sprintf(buf, "%hu\n", bond->params.ad_user_port_key);
 
 	return 0;