  It is shown that the models of white hole interacting with external matter
can be made stable by introduction of a negative central mass. Similar results
are obtained for the models of white hole, interacting with null shells, with
radial flows of matter and with photon gas. In realistic models, a naked
timelike singularity corresponding to the negative mass is hidden under a coat
of positive mass, providing an extremely strong redshift for photons born in
the Planck neighborhood of the singularity and observed at infinity, thereby
realizing the principle of cosmic censorship in a relaxed form.
