Security readout for executives and security teams
Plain-English summary
A race condition in Linux OCFS2 can corrupt filesystem metadata when hole punching overlaps asynchronous direct I/O. The filesystem may protect itself by becoming read-only, interrupting writes and requiring offline repair. Exploitation requires local, low-privileged access and a system using OCFS2.
Executive priority
Prioritize affected shared or business-critical OCFS2 systems because successful triggering can corrupt data and stop writes. Patch through normal emergency-change procedures after identifying exposure. Lower priority for systems that do not mount OCFS2 or lack relevant local workload access.
Technical view
Concurrent fallocate hole punching can remove an unwritten OCFS2 extent before the direct-I/O completion worker marks it written. The worker then cannot locate the extent, producing on-disk corruption and potentially forcing the filesystem read-only. The kernel fix waits for outstanding direct I/O before fallocate or hole-punch processing.
Likely exposure
Exposure is limited to Linux systems using OCFS2 on affected kernel versions, particularly where local users or workloads can perform concurrent asynchronous direct I/O and hole punching. Systems not using OCFS2 are not implicated by the supplied evidence.
Exploitation context
The CVSS 3.1 score is 7.8 with local access, low complexity, low privileges, and no user interaction. The supplied record is not in KEV and provides no evidence of active exploitation. Demonstrated impact comes from filesystem regression testing that produced corruption and read-only operation.
Researcher notes
The failure involves synchronization between extent removal and direct-I/O completion, specifically around ip_alloc_sem and inode locking. The supplied trace shows ocfs2_search_extent_list failing after ocfs2_remove_extent removed the target extent. No CWE classification or public exploitation evidence is supplied.
Mitigation direction
- Install a vendor-supported kernel containing the referenced OCFS2 fix.
- Consult the Linux distribution's advisory to map fixed packages to deployed kernels.
- Until patched, restrict untrusted local access to affected OCFS2 filesystems.
- Back up important OCFS2 data before maintenance or recovery operations.
Validation and detection
- Inventory running kernel versions and systems with mounted OCFS2 filesystems.
- Confirm the installed kernel includes the applicable referenced stable-kernel fix.
- Review kernel logs for OCFS2 corruption, missing extents, or read-only transitions.
- Run vendor-approved regression testing only on disposable, backed-up test filesystems.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
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ATT&CK lookup starting points
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CVE-2024-40943 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9LinuxVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/3c26b5d21b1239e9c7fd31ba7d9b2d7bdbaa68d9CVE reference, Linux
- https://git.kernel.org/stable/c/e8e2db1adac47970a6a9225f3858e9aa0e86287fCVE reference, Linux
- https://git.kernel.org/stable/c/050ce8af6838c71e872e982b50d3f1bec21da40eCVE reference, Linux
- https://git.kernel.org/stable/c/38825ff9da91d2854dcf6d9ac320a7e641e10f25CVE reference, Linux
- https://git.kernel.org/stable/c/ea042dc2bea19d72e37c298bf65a9c341ef3fff3CVE reference, Linux
- https://git.kernel.org/stable/c/3c361f313d696df72f9bccf058510e9ec737b9b1CVE reference, Linux
- https://git.kernel.org/stable/c/117b9c009b72a6c2ebfd23484354dfee2d9570d2CVE reference, Linux
- https://git.kernel.org/stable/c/952b023f06a24b2ad6ba67304c4c84d45bea2f18CVE reference, Linux
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.htmlCVE reference, CVE
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.