LiveActive security incident?Get immediate response
CVE Record

CVE-2026-46017: mm: fix deferred split queue races during migration

In the Linux kernel, the following vulnerability has been resolved: mm: fix deferred split queue races during migration migrate_folio_move() records the deferred split queue state from src and replays it on dst. Replaying it after remove_migration_ptes(src, dst, 0) makes dst visible before it is requeued, so a concurrent rmap-removal path can mark dst partially mapped and trip the WARN in deferred_split_folio(). Move the requeue before remove_migration_ptes() so dst is back on the deferred split queue before it becomes visible again. Because migration still holds dst locked at that point, teach deferred_split_scan() to requeue a folio when folio_trylock() fails. Otherwise a fully mapped underused folio can be dequeued by the shrinker and silently lost from split_queue. [ziy@nvidia.com: move the comment]

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel memory-management race in folio migration. Under concurrent memory activity, a folio can become visible before it is properly returned to a deferred split queue, causing a kernel WARN or queue-tracking loss. The source bundle does not provide CVSS, impact severity, or exploitation evidence.

Executive priority

Treat this as a kernel maintenance item until more impact data appears. Patch affected Linux systems through normal kernel update channels, with higher priority for infrastructure where kernel instability would affect critical workloads.

Technical view

The flaw is in migrate_folio_move() handling of deferred split queue state. Requeueing after remove_migration_ptes() exposes the destination folio before queue restoration, allowing concurrent rmap-removal behavior to mark it partially mapped and trigger deferred_split_folio(). The fix reorders requeueing and adjusts deferred_split_scan() handling when folio_trylock() fails.

Likely exposure

Exposure appears limited to Linux systems running the affected kernel versions or vulnerable commits identified in the CVE data. The bundle lists Linux 7.0.4 and 7.1 as affected, but distribution backports may change practical exposure.

Exploitation context

The CVE is not marked KEV, and the provided sources do not claim active exploitation or public weaponization. Preconditions, attacker privileges, and real-world impact are not documented in the bundle, so exploitation assumptions should remain conservative.

Researcher notes

The public record describes a race and corrective patch behavior but lacks CVSS, CWE, exploitability, privilege requirements, and concrete impact beyond WARN/queue loss. Focus validation on vulnerable kernel lineage and vendor backport mapping rather than speculative exploit scenarios.

Mitigation direction

  • Check Linux stable commits and distribution advisories for the official fixed kernel package.
  • Prioritize updates for systems running affected Linux 7.0.4 or 7.1 kernels.
  • Confirm whether your distribution has backported the fix into differently numbered kernels.
  • Monitor kernel logs for related memory-management WARNs until patched.

Validation and detection

  • Inventory kernel versions across Linux servers, containers hosts, and appliances.
  • Compare running kernels against vendor advisories and the referenced stable commits.
  • Review kernel logs for deferred_split_folio or folio migration WARN messages.
  • Confirm patched kernels are booted, not merely installed.
Prepared
Confidence
medium
Sources
4

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.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2026-46017 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
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
0ADP providers
3Source links

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.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, 0unaffected
LinuxLinux7.0.4, 7.1affected
Weakness

CWE details

No CWE listed

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