Re: [PATCH v3 1/2] net: tap: check if the file descriptor is valid before using it

[Jason Wang]

On 2020/7/2 上午3:39, Laurent Vivier wrote:

+void qemu_set_nonblock(int fd)
+{
+    int f;
+    f = qemu_try_set_nonblock(fd);
+    assert(f == 0);
  }

So we keep this assert which means it can still be triggered from monitor?

I don't check all the callers, but I got:

in tap_init_one() we had:

        if (vhostfdname) {
            vhostfd = monitor_fd_param(cur_mon, vhostfdname, &err);
            if (vhostfd == -1) {
                if (tap->has_vhostforce && tap->vhostforce) {
                    error_propagate(errp, err);
                } else {
                    warn_report_err(err);
                }
                return;
            }
            qemu_set_nonblock(vhostfd);
        } else {

and in net_init_socket() we had:

    if (sock->has_fd) {
        int fd;

        fd = monitor_fd_param(cur_mon, sock->fd, errp);
        if (fd == -1) {
            return -1;
        }
        qemu_set_nonblock(fd);
        if (!net_socket_fd_init(peer, "socket", name, fd, 1, sock->mcast,
                                errp)) {
            return -1;
        }
        return 0;
    }

Thanks