KVM: s390: Fix length check __import_wp_info()

Answer in brief

CVE-2026-89926 records a Unknown severity vulnerability in KVM: s390: Fix length check __import_wp_info(). 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.

Published Sep 16, 2026Updated Sep 16, 2026Source checked Sep 16, 2026First seen by HOL Sep 16, 2026Material review Sep 16, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

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.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=27291e2165b6de70c476b7b675308113edd69a60 <aef540194effd768bed0bd2e6a74fe135a3d7c3a \|\| >=27291e2165b6de70c476b7b675308113edd69a60 <71153d3262517e1c02c3a66aa5094f279b2d1454 \|\| >=27291e2165b6de70c476b7b675308113edd69a60 <fec89d327d9b2b669b5bbdac209386c6317c3722 \|\| >=27291e2165b6de70c476b7b675308113edd69a60 <b94ab9caa5d72c78226121cccff5e33f946da900 \|\| >=27291e2165b6de70c476b7b675308113edd69a60 <beb9c55af609c4c7308259d7191688c75a4e3d4a \|\| >=27291e2165b6de70c476b7b675308113edd69a60 <3fe801db90bdeefb0bbdda42d832846b53f64f8a \|\| >=27291e2165b6de70c476b7b675308113edd69a60 <4c07680a467e2f7697245bcd11691bffb2a6f0ed	aef540194effd768bed0bd2e6a74fe135a3d7c3a, 71153d3262517e1c02c3a66aa5094f279b2d1454, fec89d327d9b2b669b5bbdac209386c6317c3722, b94ab9caa5d72c78226121cccff5e33f946da900, beb9c55af609c4c7308259d7191688c75a4e3d4a, 3fe801db90bdeefb0bbdda42d832846b53f64f8a, 4c07680a467e2f7697245bcd11691bffb2a6f0ed
Linux/Linuxgeneric	3.16	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to aef540194effd768bed0bd2e6a74fe135a3d7c3a if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 16, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Fix length check __import_wp_info() struct kvm_hw_breakpoint::len is a __u64 that is fully controlled by user space. This is then assigned to wp_info->len, which is an int. The bounds check is done on the truncated value while the allocation uses the untruncated one: wp_info->len = bp_data->len; [...] if (wp_info->len < 0 || wp_info->len > MAX_WP_SIZE) return -EINVAL; wp_info->old_data = kmalloc(bp_data->len, GFP_KERNEL_ACCOUNT); Use the validated value for the allocation as intended. Without this fix userspace can trigger >4GB allocations which will fail and result in a WARN due to MAX_PAGE_ORDER.

Quoted source text, attributed separately from HOL analysis.