Security readout for executives and security teams
Plain-English summary
A flaw in the Linux kernel’s Btrfs write-error handling can leave a memory page unexpectedly unlocked, triggering a kernel assertion and system crash. Exploitation requires local, low-privileged access according to the supplied CVSS vector. The demonstrated impact is denial of service; broader confidentiality or integrity impact is not established by the technical description.
Executive priority
Treat as a high-priority availability issue on affected Btrfs systems, especially shared hosts permitting untrusted local activity. Patch through normal emergency kernel maintenance procedures. Internet exposure alone does not establish exploitability because the supplied vector requires local access, and active exploitation is not documented.
Technical view
During Btrfs buffered writes, cow_file_range_inline() could unlock a folio despite its caller expecting locked_page to remain locked. Subsequent __extent_writepage() processing could call btrfs_folio_end_all_writers() on that unlocked folio, causing an assertion failure and kernel panic. The cited kernel commits correct the error-path locking behavior.
Likely exposure
Exposure centers on Linux systems using affected 6.10-series kernel code with Btrfs, particularly where local users or workloads can exercise buffered writes and I/O-error paths. The supplied affected-version data is ambiguous at its boundaries, so kernel and distribution advisories should determine whether a specific build contains the fix.
Exploitation context
The supplied CVSS score is 7.8 with local access and low privileges required. The issue was reproduced through syzbot and repeated filesystem testing involving intentional I/O errors. CISA KEV status is false, and the supplied sources provide no evidence of active exploitation or a public weaponized exploit.
Researcher notes
The source narrative demonstrates an assertion-triggered kernel panic after a folio is unlocked on an error path. Although the CVSS vector assigns high confidentiality, integrity, and availability impacts, the supplied technical evidence directly establishes only availability loss. No CWE is supplied, and exact version boundaries should be verified against upstream or distribution records.
Mitigation direction
- Install a vendor-supported kernel containing either cited upstream fix.
- Prioritize systems using Btrfs and allowing untrusted local workloads.
- Consult the Linux distribution’s advisory for exact fixed package versions.
- Restrict unnecessary local access until affected systems are updated.
Validation and detection
- Record the running kernel version and distribution package release.
- Identify systems with mounted or configured Btrfs filesystems.
- Check vendor changelogs for CVE-2024-42266 or either cited fix commit.
- After updating and rebooting, confirm the patched kernel is running.
- Review kernel logs for Btrfs assertion failures, BUG messages, or unexpected panics.
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
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CVE-2024-42266 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/061e41581606000a83ce0f0f01d6ad338f3704e9CVE reference, Linux
- https://git.kernel.org/stable/c/478574370bef7951fbd9ef5155537d6cbed49472CVE reference, Linux
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.