CVE-2026-80558
Received Received - Intake

Heap-based Buffer Overflow in Linux Kernel Ceph Client

Vulnerability report for CVE-2026-80558, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-08-26

Last updated on: 2026-08-26

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: libceph: Avoid using invalid osd indices from primary_temp A corrupted osdmap received from a Ceph monitor or OSD may contain osd indices in its pg_temp, primary_temp, pg_upmap, and pg_upmap_items parts that don't exist, i.e., that are greater than max_osd or smaller than CEPH_HOMELESS_OSD (-1). These indices are used to create the up and acting set in ceph_pg_to_up_acting_osds(), called from calc_target(). While most of these osd indices are checked, the one from primary_temp is not. Subsequently, this may lead to calc_target() returning this (potentially invalid) index as target osd for a (linger) request. Because the osd_state, osd_weight, and osd_addr arrays only contain max_osd entries (with indices 0 to max_osd -1), this leads to out-of-bounds accesses when trying to read values from these arrays. This patch fixes the issue by adding a check to get_temp_osds(), so that only valid osd indices from primary_temp are used, and it falls back to using the primary from pg_temp or the up set if it is invalid. [ idryomov: changelog ]

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Meta Information

Published
2026-08-26
Last Modified
2026-08-26
Generated
2026-08-26
AI Q&A
2026-08-26
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
ceph ceph *

Helpful Resources

Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves a flaw in the Ceph distributed storage system. A corrupted osdmap from a Ceph monitor or OSD may contain invalid osd indices in primary_temp that exceed the maximum allowed osd index or fall below the minimum. These invalid indices are used to determine the target OSD for requests, leading to out-of-bounds memory access when the system tries to read from arrays that only have valid osd entries.

Detection Guidance

This vulnerability involves invalid OSD indices in Ceph's osdmap. Detection requires checking Ceph cluster logs for corrupted osdmap entries or invalid OSD indices in pg_temp, primary_temp, pg_upmap, or pg_upmap_items. Monitor logs for out-of-bounds access errors or crashes in OSDs or monitors.

Impact Analysis

This vulnerability could cause system crashes or instability due to out-of-bounds memory access. It may also lead to data corruption or unauthorized access if an attacker manipulates the osdmap to include malicious indices. Systems relying on Ceph for storage could experience service disruptions or data loss.

Mitigation Strategies

Apply the Linux kernel patch that adds validation for primary_temp OSD indices. Update Ceph to the patched version. Monitor OSD logs for invalid index errors and restart affected OSDs if corruption is detected. Ensure osdmap corruption is not present in recent logs.

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