CVE-2026-80958

Received Received - Intake

dm-pcache Segment Data Region Read in Linux Kernel

Publication date: 2026-09-11

Last updated on: 2026-09-13

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: dm-pcache: clamp the tail kset read to the segment data region The tail-kset read in cache_replay(), the writeback worker and the GC worker bounds its length by PCACHE_SEG_SIZE - seg_off, the raw segment size rather than the data region. A tail near the segment end reads past the segment data into the following control area. Clamp the read to cache_seg_remain(), the data region.

CVSS Scores

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Meta Information

Published

2026-09-11

Last Modified

2026-09-13

Generated

2026-10-02

AI Q&A

2026-09-12

EPSS Evaluated

2026-10-01

NVD

CVE-2026-80958

EUVD

EUVD-2026-76281

Affected Vendors & Products

Vendor	Product	Version / Range
linux	linux_kernel	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-UNKNOWN

Attack-Flow Graph

Executive Summary

This vulnerability in the Linux kernel involves a bounds-checking issue in the dm-pcache (device-mapper persistent cache) component. The problem occurs in functions like cache_replay(), writeback worker, and GC worker where a read operation near the end of a segment incorrectly uses the full segment size instead of the actual data region size. This causes the read to extend past the intended data area into adjacent control structures, potentially corrupting or exposing unintended memory.

Detection Guidance

This vulnerability is specific to the Linux kernel's dm-pcache module. Detection requires checking kernel logs for errors related to dm-pcache or segment read issues. Commands like dmesg | grep dm-pcache or journalctl -k | grep dm-pcache may help identify related errors.

Impact Analysis

This vulnerability could lead to data corruption, system crashes, or privilege escalation if exploited. Attackers might read sensitive kernel memory or manipulate cache operations to cause instability. Systems using dm-pcache for storage caching are primarily affected, potentially impacting performance and reliability.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or other common standards and regulations. It is a low-level kernel memory access issue in the Linux dm-pcache subsystem that could lead to data corruption or crashes but does not involve unauthorized data exposure or privacy violations.

Mitigation Strategies

Update the Linux kernel to the latest patched version to resolve this issue. If immediate patching is not possible, disable the dm-pcache module using modprobe -r dm-pcache or ensure no systems rely on this feature until patched.

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