selinux: do not report error on connect(AF_UNSPEC)

[ Upstream commit c7e0d6cca86581092cbbf2cd868b3601495554cf ]

calling connect(AF_UNSPEC) on an already connected TCP socket is an
established way to disconnect() such socket. After commit 68741a8adab9
("selinux: Fix ltp test connect-syscall failure") it no longer works
and, in the above scenario connect() fails with EAFNOSUPPORT.

Fix the above falling back to the generic/old code when the address family
is not AF_INET{4,6}, but leave the SCTP code path untouched, as it has
specific constraints.

Fixes: 68741a8adab9 ("selinux: Fix ltp test connect-syscall failure")
Reported-by: Tom Deseyn <tdeseyn@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index cba19b8..70bad15 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4800,7 +4800,7 @@ static int selinux_socket_connect_helper(struct socket *sock,
                struct lsm_network_audit net = {0,};
                struct sockaddr_in *addr4 = NULL;
                struct sockaddr_in6 *addr6 = NULL;
-               unsigned short snum;
+               unsigned short snum = 0;
                u32 sid, perm;
 
                /* sctp_connectx(3) calls via selinux_sctp_bind_connect()
@@ -4823,12 +4823,12 @@ static int selinux_socket_connect_helper(struct socket *sock,
                        break;
                default:
                        /* Note that SCTP services expect -EINVAL, whereas
-                        * others expect -EAFNOSUPPORT.
+                        * others must handle this at the protocol level:
+                        * connect(AF_UNSPEC) on a connected socket is
+                        * a documented way disconnect the socket.
                         */
                        if (sksec->sclass == SECCLASS_SCTP_SOCKET)
                                return -EINVAL;
-                       else
-                               return -EAFNOSUPPORT;
                }
 
                err = sel_netport_sid(sk->sk_protocol, snum, &sid);