From: Stefano Garzarella sgarzare@redhat.com
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: d021c344051a ("VSOCK: Introduce VM Sockets") Signed-off-by: Stefano Garzarella sgarzare@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/vmw_vsock/af_vsock.c | 8 +++++--- net/vmw_vsock/hyperv_transport.c | 4 ---- 2 files changed, 5 insertions(+), 7 deletions(-)
--- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -926,10 +926,12 @@ static int vsock_shutdown(struct socket */
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; @@ -938,10 +940,8 @@ static int vsock_shutdown(struct socket /* 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); @@ -949,6 +949,8 @@ static int vsock_shutdown(struct socket } }
+out: + release_sock(sk); return err; }
--- a/net/vmw_vsock/hyperv_transport.c +++ b/net/vmw_vsock/hyperv_transport.c @@ -474,14 +474,10 @@ static void hvs_shutdown_lock_held(struc
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; }