From: Seth Forshee sforshee@digitalocean.com
commit b9208492fcaecff8f43915529ae34b3bcb03877c upstream.
vsock_connect() expects that the socket could already be in the TCP_ESTABLISHED state when the connecting task wakes up with a signal pending. If this happens the socket will be in the connected table, and it is not removed when the socket state is reset. In this situation it's common for the process to retry connect(), and if the connection is successful the socket will be added to the connected table a second time, corrupting the list.
Prevent this by calling vsock_remove_connected() if a signal is received while waiting for a connection. This is harmless if the socket is not in the connected table, and if it is in the table then removing it will prevent list corruption from a double add.
Note for backporting: this patch requires d5afa82c977e ("vsock: correct removal of socket from the list"), which is in all current stable trees except 4.9.y.
Fixes: d021c344051a ("VSOCK: Introduce VM Sockets") Signed-off-by: Seth Forshee sforshee@digitalocean.com Reviewed-by: Stefano Garzarella sgarzare@redhat.com Link: https://lore.kernel.org/r/20220217141312.2297547-1-sforshee@digitalocean.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/vmw_vsock/af_vsock.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1400,6 +1400,7 @@ static int vsock_connect(struct socket * sk->sk_state = sk->sk_state == TCP_ESTABLISHED ? TCP_CLOSING : TCP_CLOSE; sock->state = SS_UNCONNECTED; vsock_transport_cancel_pkt(vsk); + vsock_remove_connected(vsk); goto out_wait; } else if (timeout == 0) { err = -ETIMEDOUT;