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CVE Record

CVE-2023-53496: x86/platform/uv: Use alternate source for socket to node data

In the Linux kernel, the following vulnerability has been resolved: x86/platform/uv: Use alternate source for socket to node data The UV code attempts to build a set of tables to allow it to do bidirectional socket<=>node lookups. But when nr_cpus is set to a smaller number than actually present, the cpu_to_node() mapping information for unused CPUs is not available to build_socket_tables(). This results in skipping some nodes or sockets when creating the tables and leaving some -1's for later code to trip. over, causing oopses. The problem is that the socket<=>node lookups are created by doing a loop over all CPUs, then looking up the CPU's APICID and socket. But if a CPU is not present, there is no way to start this lookup. Instead of looping over all CPUs, take CPUs out of the equation entirely. Loop over all APICIDs which are mapped to a valid NUMA node. Then just extract the socket-id from the APICID. This avoid tripping over disabled CPUs.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue can crash affected systems when the kernel’s UV platform code builds CPU socket and NUMA node lookup tables while some CPUs are disabled by configuration. The public record does not provide CVSS, CWE, or active exploitation evidence, so urgency depends on whether your Linux estate uses this specific platform path.

Executive priority

Treat this as a targeted infrastructure stability issue. Prioritize validation on specialized Linux hosts using the UV platform path, then patch through normal kernel maintenance unless local evidence shows crashes or critical workload impact.

Technical view

The UV x86 platform code built socket-to-node and node-to-socket tables by iterating CPUs. If nr_cpus is lower than physically present CPUs, mapping data for unused CPUs is unavailable, leaving -1 entries that later cause kernel oopses. The fix derives socket data from APIC IDs mapped to valid NUMA nodes instead.

Likely exposure

Likely exposure is limited to Linux kernels using x86/platform/uv code, especially affected kernel versions listed around 6.5 through 6.5.5 and 6.6, with nr_cpus set below the actual CPU count. The source bundle does not identify broader products or distributions.

Exploitation context

The CVE is not marked KEV, and the provided sources do not claim active exploitation or public exploit availability. The described failure mode is a kernel oops caused by specific CPU enumeration conditions, suggesting operational availability risk rather than proven remote compromise.

Researcher notes

Evidence is limited to the CVE description and two Linux stable commits. No CVSS, CWE, exploit status, or distribution-specific package mapping is provided. Validate exposure by kernel code path, version, and nr_cpus configuration rather than assuming all Linux systems are affected.

Mitigation direction

  • Check vendor or distribution kernel advisories for fixed packages referencing this CVE.
  • Update affected Linux kernels to versions containing the stable fixes.
  • Review systems using x86/platform/uv before prioritizing emergency remediation.
  • Avoid nr_cpus values below installed CPU count where operationally feasible until patched.

Validation and detection

  • Inventory Linux kernel versions across relevant x86 infrastructure.
  • Identify systems that load or depend on x86/platform/uv code.
  • Check boot parameters for nr_cpus limiting CPUs below hardware count.
  • Confirm installed kernels include the referenced stable commits or vendor backports.
  • Review kernel logs for related oops events on affected systems.
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

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CVE-2023-53496 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
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
LinuxLinux8a50c58519271dd24ba760bb282875f6ad66ee71, 8a50c58519271dd24ba760bb282875f6ad66ee71unaffected
LinuxLinux6.5, 0, 6.5.5, 6.6affected
Weakness

CWE details

No CWE listed

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