CVE-2026-72160
Received Received - Intake

OCFS2 Inode Validation Flaw Allows Metadata Forgery

Vulnerability report for CVE-2026-72160, 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 dinodes with non-canonical i_mode type Patch series "ocfs2: harden inode validators against forged metadata", v2. This series adds three structural checks to OCFS2 dinode validation so malformed on-disk fields are rejected before ocfs2_populate_inode() copies them into the in-core inode. The checks cover: - i_mode values whose type bits do not name a canonical POSIX file type; - non-device dinodes whose id1.dev1.i_rdev field is non-zero; and - non-inline dinodes that claim non-zero i_size while i_clusters is zero, covering directories unconditionally and regular files on non-sparse volumes. The normal read path reports these through ocfs2_error(), matching the existing suballoc-slot, inline-data, chain-list, and refcount checks. The online filecheck path uses the same structural predicates but keeps its own reporting contract, returning OCFS2_FILECHECK_ERR_INVALIDINO instead of calling ocfs2_error(). This patch (of 3): ocfs2_validate_inode_block() currently accepts any non-zero i_mode value. ocfs2_populate_inode() then copies that mode verbatim into inode->i_mode and dispatches on i_mode & S_IFMT to the file/dir/symlink/special_file iops; an unrecognised type falls through to ocfs2_special_file_iops and init_special_inode(). Reject dinodes whose type bits do not name one of the seven canonical POSIX file types. Use fs_umode_to_ftype(), the same generic file-type conversion helper OCFS2 already uses for directory entries, so the accepted inode type set matches the kernel file-type vocabulary instead of open-coding a local switch. Apply the same structural check to the online filecheck read path. filecheck keeps its own error namespace, so it reports malformed i_mode through the filecheck logger and OCFS2_FILECHECK_ERR_INVALIDINO instead of calling ocfs2_error(), but it must not allow a malformed dinode to 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 OCFS2 (Oracle Cluster File System) where malformed on-disk fields in dinodes (disk inodes) are not properly validated. Specifically, it rejects dinodes with non-canonical i_mode types, meaning file types that do not match standard POSIX file types. This prevents forged metadata from being copied into the in-core inode, which could otherwise lead to incorrect file handling or security issues.

Detection Guidance

This vulnerability affects the OCFS2 filesystem in the Linux kernel and is related to malformed inode metadata. Detection requires checking for filesystem corruption or invalid inode modes on OCFS2 volumes. Use fsck.ocfs2 with the -n option for a dry run to check for errors without fixing them. Also, monitor kernel logs for ocfs2_error messages indicating invalid inode types.

Impact Analysis

If exploited, this vulnerability could allow an attacker to manipulate file metadata in OCFS2, potentially causing system instability, unauthorized file access, or privilege escalation. It may also lead to data corruption or denial-of-service conditions if malformed dinodes are processed by the kernel.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. The issue is specific to the Linux kernel's OCFS2 filesystem, where malformed inode metadata could lead to filesystem corruption or errors. Compliance impacts would only occur if such corruption disrupted data integrity or availability in systems handling regulated data.

Mitigation Strategies

Apply the kernel patch that adds validation for i_mode values in OCFS2 dinodes. Ensure your system runs a kernel version with the fix. If using OCFS2, run fsck.ocfs2 to repair any corrupted inodes. Avoid mounting untrusted OCFS2 volumes until patched.

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