Processor vulnerability
CVE-2021-46778
On Zen to Zen 4 cores with SMT, measuring the contention level on the scheduler queues can leak sensitive information from the other thread.
- Name
- Execution Unit Scheduler Contention
- Also known as
- SQUIP
- Kind
- Side channel
- CVE published
- 2022-08-09 CVE record
- Advisories
- AMD-SB-1039
Researchers at Graz University of Technology and Georgia Tech showed
that by measuring the contention level on the scheduler queues of a
Zen core, one thread can leak sensitive information from the other.
It needs SMT; AMD lists Zen to Zen 4 processors and leaves the fix
to constant-time code.What the sources say of each microarchitecture.
Affected processors
5 of the 5 microarchitectures listed are affected in all or some of their models.
| Microarchitecture | Status | Detail | Source |
|---|---|---|---|
| Zen | Some models | 1st Gen EPYC (7001); Ryzen 2000 and Athlon 3000 mobile | amd.com |
| Zen+ | Some models | Ryzen 2000 desktop; Threadripper 2000 | amd.com |
| Zen 2 | Some models | 2nd Gen EPYC (7002); Ryzen 3000 desktop and 4000; Threadripper 3000 and PRO 3000 | amd.com |
| Zen 3 | Some models | 3rd Gen EPYC (7003); Ryzen 5000 and 6000; Threadripper PRO 5000 | amd.com |
| Zen 4 | Some models | 4th Gen EPYC; Ryzen 7000 desktop; Threadripper 7000 and PRO 7000 | amd.com |
Mitigations
- Programs: Constant-time algorithms and no secret-dependent control flow in the code to be protected. Source.