[NetLabel]: correct improper handling of non-NetLabel peer contexts

Fix a problem where NetLabel would always set the value of 
sk_security_struct->peer_sid in selinux_netlbl_sock_graft() to the context of
the socket, causing problems when users would query the context of the
connection.  This patch fixes this so that the value in
sk_security_struct->peer_sid is only set when the connection is NetLabel based,
otherwise the value is untouched.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 1 deletions

diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 7eb69a602d8f..d67f7e658529 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -2502,14 +2502,24 @@ void selinux_netlbl_sock_graft(struct sock *sk, struct socket *sock)
 {
         struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
         struct sk_security_struct *sksec = sk->sk_security;
+        struct netlbl_lsm_secattr secattr;
+        u32 nlbl_peer_sid;
 
         sksec->sclass = isec->sclass;
 
         if (sk->sk_family != PF_INET)
                 return;
 
+        netlbl_secattr_init(&secattr);
+        if (netlbl_sock_getattr(sk, &secattr) == 0 &&
+            selinux_netlbl_secattr_to_sid(NULL,
+                                          &secattr,
+                                          sksec->sid,
+                                          &nlbl_peer_sid) == 0)
+                sksec->peer_sid = nlbl_peer_sid;
+        netlbl_secattr_destroy(&secattr, 0);
+
         sksec->nlbl_state = NLBL_REQUIRE;
-        sksec->peer_sid = sksec->sid;
 
         /* Try to set the NetLabel on the socket to save time later, if we fail
          * here we will pick up the pieces in later calls to