selinux: make the netif cache namespace aware

While SELinux largely ignores namespaces, for good reason, there are
some places where it needs to at least be aware of namespaces in order
to function correctly.  Network namespaces are one example.  Basic
awareness of network namespaces are necessary in order to match a
network interface's index number to an actual network device.

This patch corrects a problem with network interfaces added to a
non-init namespace, and can be reproduced with the following commands:

 [NOTE: the NetLabel configuration is here only to active the dynamic
        networking controls ]

 # netlabelctl unlbl add default address:0.0.0.0/0 \
   label:system_u:object_r:unlabeled_t:s0
 # netlabelctl unlbl add default address:::/0 \
   label:system_u:object_r:unlabeled_t:s0
 # netlabelctl cipsov4 add pass doi:100 tags:1
 # netlabelctl map add domain:lspp_test_netlabel_t \
   protocol:cipsov4,100

 # ip link add type veth
 # ip netns add myns
 # ip link set veth1 netns myns
 # ip a add dev veth0 10.250.13.100/24
 # ip netns exec myns ip a add dev veth1 10.250.13.101/24
 # ip l set veth0 up
 # ip netns exec myns ip l set veth1 up

 # ping -c 1 10.250.13.101
 # ip netns exec myns ping -c 1 10.250.13.100

Reported-by: Jiri Jaburek <jjaburek@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>

1 files changed, 18 insertions, 15 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 50978d3183ea..5eb512b7ac31 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4307,15 +4307,15 @@ static int selinux_socket_unix_may_send(struct socket *sock,
                             &ad);
 }
 
-static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
-                                    u32 peer_sid,
+static int selinux_inet_sys_rcv_skb(struct net *ns, int ifindex,
+                                    char *addrp, u16 family, u32 peer_sid,
                                     struct common_audit_data *ad)
 {
         int err;
         u32 if_sid;
         u32 node_sid;
 
-        err = sel_netif_sid(ifindex, &if_sid);
+        err = sel_netif_sid(ns, ifindex, &if_sid);
         if (err)
                 return err;
         err = avc_has_perm(peer_sid, if_sid,
@@ -4408,8 +4408,8 @@ static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
                 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
                 if (err)
                         return err;
-                err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
-                                               peer_sid, &ad);
+                err = selinux_inet_sys_rcv_skb(sock_net(sk), skb->skb_iif,
+                                               addrp, family, peer_sid, &ad);
                 if (err) {
                         selinux_netlbl_err(skb, err, 0);
                         return err;
@@ -4748,7 +4748,8 @@ out:
 
 #ifdef CONFIG_NETFILTER
 
-static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
+static unsigned int selinux_ip_forward(struct sk_buff *skb,
+                                       const struct net_device *indev,
                                        u16 family)
 {
         int err;
@@ -4774,14 +4775,14 @@ static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
 
         ad.type = LSM_AUDIT_DATA_NET;
         ad.u.net = &net;
-        ad.u.net->netif = ifindex;
+        ad.u.net->netif = indev->ifindex;
         ad.u.net->family = family;
         if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
                 return NF_DROP;
 
         if (peerlbl_active) {
-                err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
-                                               peer_sid, &ad);
+                err = selinux_inet_sys_rcv_skb(dev_net(indev), indev->ifindex,
+                                               addrp, family, peer_sid, &ad);
                 if (err) {
                         selinux_netlbl_err(skb, err, 1);
                         return NF_DROP;
@@ -4810,7 +4811,7 @@ static unsigned int selinux_ipv4_forward(const struct nf_hook_ops *ops,
                                          const struct net_device *out,
                                          int (*okfn)(struct sk_buff *))
 {
-        return selinux_ip_forward(skb, in->ifindex, PF_INET);
+        return selinux_ip_forward(skb, in, PF_INET);
 }
 
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
@@ -4820,7 +4821,7 @@ static unsigned int selinux_ipv6_forward(const struct nf_hook_ops *ops,
                                          const struct net_device *out,
                                          int (*okfn)(struct sk_buff *))
 {
-        return selinux_ip_forward(skb, in->ifindex, PF_INET6);
+        return selinux_ip_forward(skb, in, PF_INET6);
 }
 #endif  /* IPV6 */
 
@@ -4908,11 +4909,13 @@ static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
         return NF_ACCEPT;
 }
 
-static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
+static unsigned int selinux_ip_postroute(struct sk_buff *skb,
+                                         const struct net_device *outdev,
                                          u16 family)
 {
         u32 secmark_perm;
         u32 peer_sid;
+        int ifindex = outdev->ifindex;
         struct sock *sk;
         struct common_audit_data ad;
         struct lsm_network_audit net = {0,};
@@ -5025,7 +5028,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
                 u32 if_sid;
                 u32 node_sid;
 
-                if (sel_netif_sid(ifindex, &if_sid))
+                if (sel_netif_sid(dev_net(outdev), ifindex, &if_sid))
                         return NF_DROP;
                 if (avc_has_perm(peer_sid, if_sid,
                                  SECCLASS_NETIF, NETIF__EGRESS, &ad))
@@ -5047,7 +5050,7 @@ static unsigned int selinux_ipv4_postroute(const struct nf_hook_ops *ops,
                                            const struct net_device *out,
                                            int (*okfn)(struct sk_buff *))
 {
-        return selinux_ip_postroute(skb, out->ifindex, PF_INET);
+        return selinux_ip_postroute(skb, out, PF_INET);
 }
 
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
@@ -5057,7 +5060,7 @@ static unsigned int selinux_ipv6_postroute(const struct nf_hook_ops *ops,
                                            const struct net_device *out,
                                            int (*okfn)(struct sk_buff *))
 {
-        return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
+        return selinux_ip_postroute(skb, out, PF_INET6);
 }
 #endif  /* IPV6 */