P2318R1 A Provenance-aware Memory Object Model for C (Jens Gustedt, Peter Sewell, Kayvan Memarian, Victor B. F. Gomes, Martin Uecker)

P2318 is an informational WG21 paper explaining the research performed and direction being pursued by WG14 for resolving the broad outstanding issue of pointer provenance (being published as a TS). The approach could presumably be adopted for C++, albeit with significantly different wording.
P2434 was written in response, proposing separate, small changes to C++ to better align with the effects of the C proposal. Its direction could also be adopted for C instead of the Provenance TS. In February 2024, SG22 reviewed the motivations for P2318 and then discussed P2434R0 with the authors of both papers present.
See minutes for details.

The strongest objection raised by the WG14 representatives was that angelic nondeterminism (which is already used in C++ and is further leveraged by P2434) renders it non-trivial to mathematically define which programs are valid (especially in the context of concurrency). It was considered unfortunate that the languages might diverge (with C instead giving pointers multiple provenances in corresponding cases), but there was no consensus to adopt either model for both.

Assigning to EWG to decide how to proceed.