vsock: prevent unnecessary refcnt inc for nonblocking connect

Currently vosck_connect() increments sock refcount for nonblocking
socket each time it's called, which can lead to memory leak if
it's called multiple times because connect timeout function decrements
sock refcount only once.

Fixes it by making vsock_connect() return -EALREADY immediately when
sock state is already SS_CONNECTING.

Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Eiichi Tsukata <eiichi.tsukata@nutanix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 7d851eb3a683074e078911e4771a8492ad4c1661..ed0df839c38ce68882047129d7514370b453f4c4 100644 (file)
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1322,6 +1322,8 @@ static int vsock_connect(struct socket *sock, struct sockaddr *addr,
                 * non-blocking call.
                 */
                err = -EALREADY;
+               if (flags & O_NONBLOCK)
+                       goto out;
                break;
        default:
                if ((sk->sk_state == TCP_LISTEN) ||