Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Tom Deseyn <tdeseyn@redhat.com>,
        Paolo Abeni <pabeni@redhat.com>,
        Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>,
        "David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.19 099/113] selinux: do not report error on connect(AF_UNSPEC)
Date:   Wed, 15 May 2019 12:56:30 +0200
Message-Id: <20190515090701.140481639@linuxfoundation.org>
In-Reply-To: <20190515090652.640988966@linuxfoundation.org>
References: <20190515090652.640988966@linuxfoundation.org>
User-Agent: quilt/0.66
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

From: Paolo Abeni <pabeni@redhat.com>

[ 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>
---
 security/selinux/hooks.c |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4800,7 +4800,7 @@ static int selinux_socket_connect_helper
 		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
 			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);