LiveActive security incident?Get immediate response
CVE Record

CVE-2024-42293: arm64: mm: Fix lockless walks with static and dynamic page-table folding

In the Linux kernel, the following vulnerability has been resolved: arm64: mm: Fix lockless walks with static and dynamic page-table folding Lina reports random oopsen originating from the fast GUP code when 16K pages are used with 4-level page-tables, the fourth level being folded at runtime due to lack of LPA2. In this configuration, the generic implementation of p4d_offset_lockless() will return a 'p4d_t *' corresponding to the 'pgd_t' allocated on the stack of the caller, gup_fast_pgd_range(). This is normally fine, but when the fourth level of page-table is folded at runtime, pud_offset_lockless() will offset from the address of the 'p4d_t' to calculate the address of the PUD in the same page-table page. This results in a stray stack read when the 'p4d_t' has been allocated on the stack and can send the walker into the weeds. Fix the problem by providing our own definition of p4d_offset_lockless() when CONFIG_PGTABLE_LEVELS <= 4 which returns the real page-table pointer rather than the address of the local stack variable.

HighCVSS 7.8Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A Linux arm64 memory-management flaw can misdirect a fast page-table walk into reading stray stack data, causing kernel crashes and potentially broader compromise. It affects a specific configuration involving 16K pages, four-level page tables, runtime folding, and no LPA2. The supplied CVSS rates confidentiality, integrity, and availability impacts as high, but exploitation requires local low-privileged access.

Executive priority

Treat as a high-priority local privilege-bound kernel issue on matching arm64 systems. Rapidly identify exposed configurations and patch them through supported vendor channels. Internet reachability alone does not create direct exposure, but multi-user hosts, containers sharing the host kernel, and systems running less-trusted local workloads deserve earlier attention.

Technical view

During fast GUP, generic p4d_offset_lockless() may return a pointer to a caller’s stack-allocated pgd_t. With runtime-folded fourth-level tables, pud_offset_lockless() calculates a PUD address from that pointer, producing a stray stack read and invalid page-table traversal. The fix adds an arm64-specific p4d_offset_lockless() returning the real page-table pointer when CONFIG_PGTABLE_LEVELS is at most four.

Likely exposure

Exposure is limited to arm64 Linux systems using 16K pages and four-level page tables where the fourth level folds dynamically because LPA2 is unavailable. The bundle lists affected version values including 6.9, 6.10.3, and 6.11, but does not clearly define their range relationships or downstream distribution mappings.

Exploitation context

The CVSS vector describes local, low-complexity exploitation requiring low privileges and no user interaction, with potentially high confidentiality, integrity, and availability impact. Reported evidence is random kernel oopses, not confirmed malicious exploitation. The CVE is not identified as being in CISA KEV, and the supplied sources do not claim active exploitation.

Researcher notes

The failure is configuration-dependent and originates from pointer handling across static and dynamic page-table folding. The supplied material documents crashes and a corrective implementation, but provides no proof of reliable privilege escalation, data disclosure, or active exploitation. Package-level affected and fixed versions require confirmation from downstream vendor advisories.

Mitigation direction

  • Apply a vendor-supported kernel containing the referenced upstream stable fix.
  • Request exact fixed-package guidance from the operating-system or appliance vendor.
  • Prioritize arm64 systems matching the 16K-page, runtime-folding configuration.
  • Reboot into the corrected kernel after installation, following operational change controls.

Validation and detection

  • Inventory arm64 kernel versions, page size, page-table levels, and LPA2 capability.
  • Confirm the running kernel includes either referenced fix or a documented downstream backport.
  • Verify the corrected kernel is active after reboot, not merely installed.
  • Review kernel logs for page-table-walk oopses associated with fast GUP.
Prepared
Confidence
high
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-2024-42293 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
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

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.

1CVSS vectors
3Timeline events
1ADP providers
3Source links

SSVC decision data

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

CVSS vector scores

1 official score

We 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.

ScoreVersionSeverityVectorExploitImpactSource
7.8CVSS 3.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9Linux

Vulnerability scoring details

Base CVSS 3.1 score

7.8High
CVSS 3.1 vector shape for CVE-2024-42293Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

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

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux0dd4f60a2c76938c2625f6c630c225699d97608b, 0dd4f60a2c76938c2625f6c630c225699d97608bunaffected
LinuxLinux6.9, 0, 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.