CVE-2026-72159
Received Received - Intake

OCFS2 Inode Validation Flaw Allows Malformed File Structures

Vulnerability report for CVE-2026-72159, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-08-15

Last updated on: 2026-08-17

Assigner: kernel.org

Description

In the Linux kernel, the following vulnerability has been resolved: ocfs2: reject non-inline dinodes with i_size and zero i_clusters On a volume mounted without OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC, a non-inline regular file with non-zero i_size and zero i_clusters is structurally malformed: the extent map declares no allocated clusters yet the size header claims content exists. Keep rejecting that shape, but express it through a shared predicate so the same invariant is available to normal inode reads and online filecheck. The same zero-cluster shape is also malformed for non-inline directories. ocfs2 directory growth allocates backing storage before advancing i_size, and ocfs2_dir_foreach_blk_el() later walks until ctx->pos reaches i_size_read(inode). A forged directory dinode with a huge i_size and no clusters would repeatedly fail on holes while advancing through the claimed size. Sparse regular files remain exempt: on sparse-alloc volumes, truncate can legitimately grow i_size without allocating clusters. System inodes and inline-data dinodes also retain their separate storage rules. Mirror the check in ocfs2_filecheck_validate_inode_block() as well. filecheck reports through its own error namespace, so malformed size/cluster state is logged as a filecheck invalid-inode result rather than via ocfs2_error(), but it must not proceed into ocfs2_populate_inode().

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Meta Information

Published
2026-08-15
Last Modified
2026-08-17
Generated
2026-09-04
AI Q&A
2026-08-15
EPSS Evaluated
2026-09-03
NVD
EUVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
oracle ocfs2 *

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 structural flaw in the OCFS2 file system. It occurs when non-inline dinodes (disk inodes) have a non-zero file size but zero allocated clusters. This malformed state can lead to issues where the file system incorrectly reports file content that doesn't exist in storage.

Detection Guidance

This vulnerability is specific to the OCFS2 filesystem in the Linux kernel and requires manual inspection of filesystem metadata. No direct network detection commands are available. Check OCFS2 volumes for malformed inodes using fsck.ocfs2 or mount-time checks. Review kernel logs for ocfs2 errors indicating invalid inode states.

Impact Analysis

This vulnerability could cause file system corruption or crashes when accessing malformed files or directories. It may lead to data loss or system instability if exploited by an attacker to create specially crafted files that trigger the issue.

Compliance Impact

This vulnerability does not directly affect compliance with standards like GDPR or HIPAA. It is a structural integrity issue in the OCFS2 filesystem that could lead to data corruption or filesystem errors, but no evidence suggests it impacts data privacy or security controls required by these regulations.

Mitigation Strategies

Apply the latest Linux kernel patches addressing this OCFS2 issue. Ensure OCFS2 volumes are mounted with valid features. Regularly run fsck.ocfs2 to detect and repair malformed inodes. Avoid using OCFS2_FEATURE_INCOMPAT_SPARSE_ALLOC unless necessary.

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