The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 05174c95b83f8aca0c47b87115abb7a6387aafa5 Mon Sep 17 00:00:00 2001
From: Paolo Abeni pabeni@redhat.com Date: Fri, 10 May 2019 19:12:33 +0200 Subject: [PATCH] selinux: do not report error on connect(AF_UNSPEC)
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 explicitly early checking for AF_UNSPEC family, and returning success in that case.
Reported-by: Tom Deseyn tdeseyn@redhat.com Cc: stable@vger.kernel.org Fixes: 68741a8adab9 ("selinux: Fix ltp test connect-syscall failure") Suggested-by: Paul Moore paul@paul-moore.com Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Paul Moore paul@paul-moore.com
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index c61787b15f27..3ec702cf46ca 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4637,6 +4637,14 @@ static int selinux_socket_connect_helper(struct socket *sock, err = sock_has_perm(sk, SOCKET__CONNECT); if (err) return err; + if (addrlen < offsetofend(struct sockaddr, sa_family)) + return -EINVAL; + + /* connect(AF_UNSPEC) has special handling, as it is a documented + * way to disconnect the socket + */ + if (address->sa_family == AF_UNSPEC) + return 0;
/* * If a TCP, DCCP or SCTP socket, check name_connect permission @@ -4657,8 +4665,6 @@ static int selinux_socket_connect_helper(struct socket *sock, * need to check address->sa_family as it is possible to have * sk->sk_family = PF_INET6 with addr->sa_family = AF_INET. */ - if (addrlen < offsetofend(struct sockaddr, sa_family)) - return -EINVAL; switch (address->sa_family) { case AF_INET: addr4 = (struct sockaddr_in *)address;