Comment by imtringued

DMA being a problem appears to be mostly a problem with a lack of identification of the data. If the shape of the data could be verified by the language runtime, instead of being an arbitrary stream of bytes whose meaning must be known by the recipient without any negotiation, this form of unsafety would disappear, since the receiving code simply needs to assert the schema, which could be as simple as checking a 32 bit integer.

Then all you need to do is also verify that the sending code adheres to the schema it specified.

This has very little to do with borrow checking. From the perspective of the borrow checker, a DMA call is no different from RPC or writing to a very wide pointer.