s390/dasd: Guard sysfs discipline callbacks against unallocated private data (CVE-2026-89457) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-89457

s390/dasd: Guard sysfs discipline callbacks against unallocated private data

Answer in brief

CVE-2026-89457 records a Unknown severity vulnerability in s390/dasd: Guard sysfs discipline callbacks against unallocated private data. 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 11, 2026Updated Sep 11, 2026Source checked Sep 11, 2026First seen by HOL Sep 11, 2026Material review Sep 11, 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	>=c729696bcf8b23450043dd9c9972c15e53419ae4 <536407b272402af679155910d7fdeeb4834eefb9 \|\| >=c729696bcf8b23450043dd9c9972c15e53419ae4 <6452c13646af7c13d7f6668b6690cfb2427e7f7b \|\| >=c729696bcf8b23450043dd9c9972c15e53419ae4 <449f3bada7a9fad8b8cdf4bb20baf27ee9ca56c5 \|\| >=c729696bcf8b23450043dd9c9972c15e53419ae4 <2a1780f9fc2493bd34c418a0be6fc58943afcecf	536407b272402af679155910d7fdeeb4834eefb9, 6452c13646af7c13d7f6668b6690cfb2427e7f7b, 449f3bada7a9fad8b8cdf4bb20baf27ee9ca56c5, 2a1780f9fc2493bd34c418a0be6fc58943afcecf
Linux/Linuxgeneric	5.3	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 536407b272402af679155910d7fdeeb4834eefb9 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 11, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: s390/dasd: Guard sysfs discipline callbacks against unallocated private data Several sysfs show/store handlers call a discipline callback that dereferences device->private, either directly or through the DASD_DEFINE_ATTR() macro. During dasd_generic_set_online() the discipline is assigned before check_device() allocates device->private, so an unprivileged read of one of these world-readable attributes in that window dereferences a NULL pointer and panics. Guard the dereference inside each callback that actually touches device->private.

Quoted source text, attributed separately from HOL analysis.