Answer in brief
CVE-2026-89917 records a Unknown severity vulnerability in KVM: arm64: Handle VNCR TLB invalidation race with vcpu_put() VNCR unmapping. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=7270cc9157f474dfc46750a34c9d7defc686b2eb <5cbd8761d001c11ada73b1753d772c4745a70e72 || >=7270cc9157f474dfc46750a34c9d7defc686b2eb <9065c1261f8a05c6a7a2d90048c7c0665ab2896d || >=7270cc9157f474dfc46750a34c9d7defc686b2eb <38640bc32be3fcf9526d477155bc19d3f146231f | 5cbd8761d001c11ada73b1753d772c4745a70e72, 9065c1261f8a05c6a7a2d90048c7c0665ab2896d, 38640bc32be3fcf9526d477155bc19d3f146231f |
| Linux/Linuxgeneric | 6.16 | Not reported |
Published upstream
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 16, 2026
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Handle VNCR TLB invalidation race with vcpu_put() VNCR unmapping While VNCR TLB invalidation always occurs under the MMU lock, vcpu_put() doesn't, while it unmaps the VNCR page. The problem is that the invalidation evaluates vncr_tlb::cpu to decide whether an unmapping needs to take place (cpu != -1) before performing it. On the other hand, this_cpu_reset_vncr_fixmap() unconditionally unmaps if L1_VNCR_MAPPED is set. These two obviously can race, with a TOCTOU pattern on the TLBI path, and a BUG_ON() on the vcpu_put() path. And the two can end-up calling vncr_fixmap(-1), with extra lethal effects. Move the reset of vncr_tlb::cpu to -1 to a common function, and make this update atomic so that only a single thread can reset the field and perform the corresponding unmap. The vcpu_put() still need to unconditionally unmap the current VNCR to close another ugly race. Finally, the assignment of vncr_tlb::cpu is moved to be kept in sync with the actual mapping, similar to L1_VNCR_MAPPED being set.
Quoted source text, attributed separately from HOL analysis.