CVE-2021-28692
Description
inappropriate x86 IOMMU timeout detection / handling IOMMUs process commands issued to them in parallel with the operation of the CPU(s) issuing such commands. In the current implementation in Xen, asynchronous notification of the completion of such commands is not used. Instead, the issuing CPU spin-waits for the completion of the most recently issued command(s). Some of these waiting loops try to apply a timeout to fail overly-slow commands. The course of action upon a perceived timeout actually being detected is inappropriate: - on Intel hardware guests which did not originally cause the timeout may be marked as crashed, - on AMD hardware higher layer callers would not be notified of the issue, making them continue as if the IOMMU operation succeeded.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Fixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Fixed | 4.14.2+25-gb6a8c4f72d-1 |
| sid | Fixed | 4.14.2+25-gb6a8c4f72d-1 |
| forky | Fixed | 4.14.2+25-gb6a8c4f72d-1 |
| bullseye | Fixed | 4.14.2+25-gb6a8c4f72d-1 |
| bookworm | Fixed | 4.14.2+25-gb6a8c4f72d-1 |
References
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.