Stabilize MemorySanitizer and ThreadSanitizer Support

[nikomatsakis]

Metadata
Point of contact	@jakos-sec
Team(s)	bootstrap, compiler, infra, project-exploit-mitigations
Goal document	2026/stabilization-of-sanitizer-support

Summary

Stabilize the MemorySanitizer and ThreadSanitizer support. This includes fixing open bugs for the sanitizers to open a path for stabilization and the necessary infrastructure changes to provide precompiled and instrumented standard libraries for the sanitizers.

Tasks and status

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Note: we have updated the body to match the 2026 goal. Your original text is preserved below.

Details

Metadata
Point of contact	@jakos-sec
Team(s)	bootstrap, compiler, infra, project-exploit-mitigations
Goal document	2025h2/stabilization-of-sanitizer-support

Summary

Stabilize the MemorySanitizer and ThreadSanitizer support. This includes fixing open bugs for the sanitizers to open a path for stabilization and the necessary infrastructure changes to provide precompiled and instrumented standard libraries for the sanitizers.

Tasks and status

• Discussion and moral support (compiler, infra )
• Implementation (@jakos-sec, @1c3t3a)
• Stabilization decision (compiler )
• Standard reviews (compiler )
• Dedicated reviewer (bootstrap, project-exploit-mitigations )

[nikomatsakis]

This issue is intended for status updates only.

For general questions or comments, please contact the owner(s) directly.

[jakos-sec]

We've had a bunch of discussions and I opened a MCP (link, zulip).

I think the final sentiment was creating new targets for the few sanitizers and platforms that are critical. I'm in the process of prototyping something to get new feedback on it.

[jakos-sec]

Based on the gathered feedback I opened a new MCP for the proposed new Tier 2 targets with sanitizers enabled. (rust-lang/compiler-team#951)

[jakos-sec]

The MCP (rust-lang/compiler-team#951) has been seconded and is still waiting 3 days to be approved. Once that is done, we can proceed with merging the Tier 2 target.

[jakos-sec]

Both the MCP and the PR for the AddressSanitizer target have been merged (rust-lang/compiler-team#951, rust-lang/rust#149644). Next up I should prepare the MCP for the Memory- and ThreadSanitizer targets, hopefully sending out soon.

[jakos-sec]

The targets for MSan and TSan are merged now: rust-lang/rust#152757.

Next, I'll be working on stabilizing those two, now that we have a way to use it without other unstable features (build-std).