net: add skb_to_full_sk() helper and use it in selinux_netlbl_skbuff_setsid()

Generalize selinux_skb_sk() added in commit 212cd0895330
("selinux: fix random read in selinux_ip_postroute_compat()")
so that we can use it other contexts.

Use it right away in selinux_netlbl_skbuff_setsid()

Fixes: ca6fb0651883 ("tcp: attach SYNACK messages to request sockets instead of listener")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
index f5bf7310e3343468bddf7e51940a77ed497ad7f1..2134e6d815bcb0611a2f65cd7b4da44cb7762b8c 100644 (file)
--- a/include/net/inet_sock.h
+++ b/include/net/inet_sock.h
@@ -210,6 +210,18 @@ struct inet_sock {
 #define IP_CMSG_ORIGDSTADDR    BIT(6)
 #define IP_CMSG_CHECKSUM       BIT(7)
 
+/* SYNACK messages might be attached to request sockets.
+ * Some places want to reach the listener in this case.
+ */
+static inline struct sock *skb_to_full_sk(const struct sk_buff *skb)
+{
+       struct sock *sk = skb->sk;
+
+       if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
+               sk = inet_reqsk(sk)->rsk_listener;
+       return sk;
+}
+
 static inline struct inet_sock *inet_sk(const struct sock *sk)
 {
        return (struct inet_sock *)sk;

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index c9b2d546747787d1464ff1185d3b853ad459979c..23307da15f1db7f7cd6612805e11c0efa916550a 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4931,23 +4931,11 @@ static unsigned int selinux_ipv4_output(void *priv,
        return selinux_ip_output(skb, PF_INET);
 }
 
-/* SYNACK messages might be attached to request sockets.
- * To get back to sk_security, we need to look at the listener.
- */
-static struct sock *selinux_skb_sk(const struct sk_buff *skb)
-{
-       struct sock *sk = skb->sk;
-
-       if (sk && sk->sk_state == TCP_NEW_SYN_RECV)
-               sk = inet_reqsk(sk)->rsk_listener;
-       return sk;
-}
-
 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
                                                int ifindex,
                                                u16 family)
 {
-       struct sock *sk = selinux_skb_sk(skb);
+       struct sock *sk = skb_to_full_sk(skb);
        struct sk_security_struct *sksec;
        struct common_audit_data ad;
        struct lsm_network_audit net = {0,};
@@ -5002,7 +4990,7 @@ static unsigned int selinux_ip_postroute(struct sk_buff *skb,
        if (!secmark_active && !peerlbl_active)
                return NF_ACCEPT;
 
-       sk = selinux_skb_sk(skb);
+       sk = skb_to_full_sk(skb);
 
 #ifdef CONFIG_XFRM
        /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec

diff --git a/security/selinux/netlabel.c b/security/selinux/netlabel.c
index 0364120d1ec8705da7e8c1636f645d0885731509..1f989a539fd4abe08e3797b5d49f7b26ded4fe41 100644 (file)
--- a/security/selinux/netlabel.c
+++ b/security/selinux/netlabel.c
@@ -245,7 +245,7 @@ int selinux_netlbl_skbuff_setsid(struct sk_buff *skb,
 
        /* if this is a locally generated packet check to see if it is already
         * being labeled by it's parent socket, if it is just exit */
-       sk = skb->sk;
+       sk = skb_to_full_sk(skb);
        if (sk != NULL) {
                struct sk_security_struct *sksec = sk->sk_security;
                if (sksec->nlbl_state != NLBL_REQSKB)