KVM: arm64: Correctly handle end of VA space TLBI invalidation
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Correctly handle end of VA space TLBI invalidation Our TLB invalidation by VA code is based on comparing two ranges, one defined by the TLB, and one defined by the TLBI instruction. Each range is defined by a start and a size. However, the way the comparison is done doesn't account for address rollover, as it compares an address with (base + size). This works nicely until this expression represent the last page/block in the TTBR1 VA space, as the result is a big fat 0. And a failed TLB invalidation. Rewrite the comparison in a way that is immune to the address rollover (making the end address inclusive instead of exclusive), and move this into a common helper that is used by both VA and IPA invalidations, as suggested by Hyunwoo Kim (although the IPA version didn't suffer from this particular problem, obviously).
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.18.51, 7.2.5, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
Not affected: 6 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
- Red Hat OpenShift Container Platform 4
- Red Hat OpenShift Container Platform 5
Timeline
- 2026-10-02 Threatist record created from CVE-2026-89918
- 2026-10-03 Alias added: GHSA-hcq6-hvjh-vf66
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-11-04 Affected versions changed · Red Hat
- 2026-11-04 CVSS score added · Red Hat
References
More Linux vulnerabilities
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- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2021-02452 Incorrect authorization in Ubuntu linux kernel KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
Sources
- CVE-2026-89918 · CVE Program
- CVE-2026-89918 · NVD
- FIRST EPSS
- GHSA-hcq6-hvjh-vf66 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-89918 · Red Hat security data · CC BY 4.0
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