CVE-2026-89915
CVE.org · Published
- Record status
- Published
- Identifier year (not publication year)
- 2026
- Source publication
- Source updated
- Imported by cveboard
- Source snapshot
- cve_2026-10-24_midnight_baseline ·
CNA source text (English)
KVM: arm64: Remove VM-wide VNCR mapping counter
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Remove VM-wide VNCR mapping counter The global VNCR mapping counter is used to decide whether an L1 provided VNCR page is mapped in L0 on any CPU at the point of dealing with a TLB invalidation. It is incremented when a mapping is made in the fixmap, and decremented when unmapped. As it turns out, this tracking has several flaws: - we are trying to invalidate TLBs, and the mapping is only an opportunistic consequence of the TLB. Checking this counter to decide whether a TLB needs to be invalidated may result in missed invalidations. - an L1 vcpu invalidating its own TLB (a very likely case) will not succeed in invalidating the VNCR pseudo TLB because that page is not mapped in L0 at this stage. Given that this tracking fails at delivering the minimum guarantees that are required and is only a performance optimisation, remove it completely.
Scoped product and version facts
Fix information unknown; no fixed version is derived here. Missing information does not prove that no fix exists.
Exploitation unknown; this catalogue does not assess exploitation.
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
unaffected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 4ffa72ad8f37e73bbb6c0baa88557bcb4fd39929 | affected | git | 5453b85c7ebb605febac3df42021f9471663f051 | Unavailable | None listed |
| 4ffa72ad8f37e73bbb6c0baa88557bcb4fd39929 | affected | git | 87c2bbf189829dce4aaada8f82e3d54ccc037976 | Unavailable | None listed |
| 4ffa72ad8f37e73bbb6c0baa88557bcb4fd39929 | affected | git | c55bc773b6e814406658fae7dc5c15f639ed816e | Unavailable | None listed |
Linux
- Vendor
- Linux
- Product
- Linux
- Platforms
- Unknown
- Default status
affected
| Version (version) | Status (status) | Version scheme (versionType) | Exclusive end (lessThan) | Inclusive end (lessThanOrEqual) | Status changes (at → status) |
|---|---|---|---|---|---|
| 6.16 | affected | Unavailable | Unavailable | Unavailable | None listed |
| 0 | unaffected | semver | 6.16 | Unavailable | None listed |
| 6.18.52 | unaffected | semver | Unavailable | 6.18.* | None listed |
| 7.2.5 | unaffected | semver | Unavailable | 7.2.* | None listed |
| 7.3 | unaffected | original_commit_for_fix | Unavailable | * | None listed |