CVE-2026-80957

Received Received - Intake

dm-pcache Infinite Loop in Linux Kernel

Publication date: 2026-09-11

Last updated on: 2026-09-11

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: dm-pcache: detect a cycle in the last-kset chain during replay cache_replay() follows the on-media last-kset chain by next_cache_seg_id with no cond_resched(). A forged chain that points back into a segment it has already visited makes the replay loop follow it forever. Cap the last-kset hops at cache->n_segs; a valid chain visits each segment at most once.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-09-11

Last Modified

2026-09-11

Generated

2026-09-12

AI Q&A

2026-09-12

EPSS Evaluated

N/A

NVD

CVE-2026-80957

EUVD

EUVD-2026-76280

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 is in the Linux kernel's dm-pcache component. It involves a flaw in the cache_replay() function where a forged chain in the last-kset data structure can create an infinite loop. The function follows a chain without checking for cycles, causing it to revisit segments repeatedly if the chain points back to an already visited segment.

Detection Guidance

This vulnerability is specific to the Linux kernel's device-mapper cache target (dm-pcache). Detection requires checking kernel logs for hangs during device-mapper operations or monitoring for infinite loops in cache replay processes. No direct commands are provided in the context, but system monitoring tools like dmesg or journalctl may reveal kernel hangs related to dm-pcache.

Impact Analysis

This vulnerability could lead to a denial-of-service condition on systems using dm-pcache. An attacker could exploit it to cause the system to hang or become unresponsive by triggering the infinite loop, potentially disrupting services relying on the affected kernel component.

Mitigation Strategies

Apply the Linux kernel patch that caps the last-kset hops at cache->n_segs to prevent infinite loops. Update to a kernel version containing the fix (CVE-2026-80957). If immediate patching is not possible, disable the dm-pcache feature or restrict its use until the update is applied.

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