dm-pcache: only hand out initialized cache segments (CVE-2026-80956) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-80956

dm-pcache: only hand out initialized cache segments

Answer in brief

CVE-2026-80956 records a Unknown severity vulnerability in dm-pcache: only hand out initialized cache segments. 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	>=1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 <83e3116283ed2c6a6a1fa662862a4b4d7d2701a2 \|\| >=1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 <692037ae1a7cfacc2f0c22c6e034c1dfee0e553f \|\| >=1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 <2df0fc042e299bae3c0f60ea5cd2af9285658e9f	83e3116283ed2c6a6a1fa662862a4b4d7d2701a2, 692037ae1a7cfacc2f0c22c6e034c1dfee0e553f, 2df0fc042e299bae3c0f60ea5cd2af9285658e9f
Linux/Linuxgeneric	6.18	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 83e3116283ed2c6a6a1fa662862a4b4d7d2701a2 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: dm-pcache: only hand out initialized cache segments get_cache_segment() scans the segment map up to cache->n_segs, the physical device segment count, but cache_segs_init() only initializes the first cache_info->n_segs segments. A crafted image with cache_info->n_segs smaller than the device count leaves the remaining pcache_cache_segment structs zeroed (segment.data == NULL), and the allocator can hand one to cache_kset_close(), which writes through the returned segment's data pointer with no NULL check. Bound the allocator's search to cache_info->n_segs so only initialized segments are ever returned. A conforming cache sets n_segs equal to the device segment count, so this rejects nothing legitimate.

Quoted source text, attributed separately from HOL analysis.