A crazy thought [LWN.net]

A crazy thought

Posted Jan 20, 2026 19:00 UTC (Tue) by Cyberax (✭ supporter ✭, #52523)
In reply to: A crazy thought by mathstuf
Parent article: Task-level io_uring restrictions

Why would you? SPECTRE is not a major issue in userspace that WASM needs to take care of. Browsers prevent timing attacks by isolating different trust domains into different processes.

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A crazy thought

Posted Jan 20, 2026 21:27 UTC (Tue) by mathstuf (subscriber, #69389) [Link] (1 responses)

I'm talking about the wider WASM-over-BPF commentary.

A crazy thought

Posted Jan 20, 2026 22:36 UTC (Tue) by Cyberax (✭ supporter ✭, #52523) [Link]

I understand. My point is that no WASM runtime right now _needs_ to have SPECTRE mitigations due to the way browsers work. So nobody is working on them.

And yes, I looked at the eBPF JIT and Wasmtime and Cranelift, so I roughly understand the scope of work. It's a fair amount, but nothing extraordinary.

Also I have a deep suspicion that with all the kfuncs available to eBPF, you can find enough speculation gadgets there.