I don't think there is a one size fits all socialist policy on drugs. The British empire used the distribution of drugs as a weapon of oppression and colonization against China and as such socialism there entailed strict drug laws to ensure such a thing could never happen again. I don't necessarily agree such strict laws are still necessary, but I don't live in China so my opinion on that is irrelevant.

I can however talk about drug policies in the imperial core where the situation is reversed relative to China. Here strict drug laws are used to oppress and enslave racial minorities, and so I think any sort of progress here must involve complete decriminalization at the bare minimum. No one should be in prison for drug use.

Going beyond the bare minimum, I think full legalization is necessary as a strong harm reduction policy. That said, no one should be allowed to profit of off the legalization of addictive substances. Distribution of hard drugs should be handled by a government program.

One of the biggest reasons harder drugs are so dangerous is because criminalization has created a black market where regulation does not exist and you have no legal recourse if your dealer poisons you. This is why we need to ensure a clean supply of these drugs exists and is freely available to those who can demonstrate a history of prior use. Doing this would drastically cut down on overdoses and organized crime.