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CVE Record

CVE-2024-43832: s390/uv: Don't call folio_wait_writeback() without a folio reference

In the Linux kernel, the following vulnerability has been resolved: s390/uv: Don't call folio_wait_writeback() without a folio reference folio_wait_writeback() requires that no spinlocks are held and that a folio reference is held, as documented. After we dropped the PTL, the folio could get freed concurrently. So grab a temporary reference.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel issue in IBM s390 Ultravisor-related code. The kernel could wait on memory writeback after dropping a lock without holding the required memory-page reference, allowing concurrent freeing. Business urgency is unclear because the source bundle gives no CVSS score, no CWE, and no evidence of active exploitation.

Executive priority

Track and remediate through normal kernel patch management, with priority for s390 infrastructure. Escalate only if vendor guidance identifies exploitable local impact in your environment.

Technical view

The flaw is in Linux s390/uv handling around folio_wait_writeback(). Kernel documentation requires no spinlocks held and a valid folio reference. The CVE states the page table lock was dropped, so the folio could be freed concurrently. Stable commits fix this by taking a temporary folio reference.

Likely exposure

Exposure appears limited to Linux systems using affected kernel builds on s390 architecture paths involving s390/uv. The bundle lists Linux as affected but does not provide a complete, normalized version range or distribution matrix.

Exploitation context

The bundle says KEV is false and provides no cited evidence of active exploitation, public exploit availability, or real-world attacks. Treat exploitation status as unconfirmed.

Researcher notes

The available evidence supports a concurrency lifetime bug in s390/uv memory handling. The likely class is use-after-free risk, but the bundle does not assign CWE, CVSS, attack vector, privileges required, or impact. Avoid overstating exploitability.

Mitigation direction

  • Apply kernel updates containing the referenced stable fixes.
  • Check distribution advisories, including Debian LTS, for packaged kernel updates.
  • Prioritize s390 Linux hosts and virtualized environments using s390/uv functionality.
  • Do not assume non-s390 systems are exposed without vendor confirmation.

Validation and detection

  • Inventory Linux kernel versions on s390 systems.
  • Map installed kernels against vendor advisories and stable fix commits.
  • Confirm patched kernels include the referenced s390/uv folio reference fix.
  • Review Debian LTS applicability if using Debian-based s390 systems.
Prepared
Confidence
medium
Sources
7

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

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.

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CVE-2024-43832 mapping review

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
3Timeline events
2ADP providers
6Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux214d9bbcd3a67230b932f6cea83c078ab34d9e70, 214d9bbcd3a67230b932f6cea83c078ab34d9e70, 214d9bbcd3a67230b932f6cea83c078ab34d9e70, 214d9bbcd3a67230b932f6cea83c078ab34d9e70unaffected
LinuxLinux5.7, 0, 6.1.103, 6.6.44, 6.10.3, 6.11affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.