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Commit b3c91763 authored by Stefano Garzarella's avatar Stefano Garzarella Committed by Greg Kroah-Hartman
Browse files

vsock: fix locking in vsock_shutdown() 



commit 1c5fae9c9a092574398a17facc31c533791ef232 upstream.

In vsock_shutdown() we touched some socket fields without holding the
socket lock, such as 'state' and 'sk_flags'.

Also, after the introduction of multi-transport, we are accessing
'vsk->transport' in vsock_send_shutdown() without holding the lock
and this call can be made while the connection is in progress, so
the transport can change in the meantime.

To avoid issues, we hold the socket lock when we enter in
vsock_shutdown() and release it when we leave.

Among the transports that implement the 'shutdown' callback, only
hyperv_transport acquired the lock. Since the caller now holds it,
we no longer take it.

Fixes: d021c344 ("VSOCK: Introduce VM Sockets")
Signed-off-by: default avatarStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent afb1f8a1

net/vmw_vsock/af_vsock.c

+5 −3
Original line number Diff line number Diff line
@@ -816,10 +816,12 @@ static int vsock_shutdown(struct socket *sock, int mode) 
	 */



	sk = sock->sk;



	lock_sock(sk);

	if (sock->state == SS_UNCONNECTED) {

		err = -ENOTCONN;

		if (sk->sk_type == SOCK_STREAM)

			return err;

			goto out;

	} else {

		sock->state = SS_DISCONNECTING;

		err = 0;
@@ -828,10 +830,8 @@ static int vsock_shutdown(struct socket *sock, int mode) 
	/* Receive and send shutdowns are treated alike. */

	mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);

	if (mode) {

		lock_sock(sk);

		sk->sk_shutdown |= mode;

		sk->sk_state_change(sk);

		release_sock(sk);



		if (sk->sk_type == SOCK_STREAM) {

			sock_reset_flag(sk, SOCK_DONE);
@@ -839,6 +839,8 @@ static int vsock_shutdown(struct socket *sock, int mode) 
		}

	}



out:

	release_sock(sk);

	return err;

}

net/vmw_vsock/hyperv_transport.c

+0 −4
Original line number Diff line number Diff line
@@ -443,14 +443,10 @@ static void hvs_shutdown_lock_held(struct hvsock *hvs, int mode) 


static int hvs_shutdown(struct vsock_sock *vsk, int mode)

{

	struct sock *sk = sk_vsock(vsk);



	if (!(mode & SEND_SHUTDOWN))

		return 0;



	lock_sock(sk);

	hvs_shutdown_lock_held(vsk->trans, mode);

	release_sock(sk);

	return 0;

}