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CVE Record

CVE-2025-38071: x86/mm: Check return value from memblock_phys_alloc_range()

In the Linux kernel, the following vulnerability has been resolved: x86/mm: Check return value from memblock_phys_alloc_range() At least with CONFIG_PHYSICAL_START=0x100000, if there is < 4 MiB of contiguous free memory available at this point, the kernel will crash and burn because memblock_phys_alloc_range() returns 0 on failure, which leads memblock_phys_free() to throw the first 4 MiB of physical memory to the wolves. At a minimum it should fail gracefully with a meaningful diagnostic, but in fact everything seems to work fine without the weird reserve allocation.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2025-38071 is a Linux kernel x86 memory-management flaw that can cause a kernel crash during early memory setup under constrained contiguous-memory conditions. The public record does not provide CVSS, CWE, or evidence of active exploitation.

Executive priority

Treat as an operational reliability issue until vendor severity is clearer. Prioritize patching for embedded, appliance, industrial, or custom-kernel systems where boot failure has high business impact.

Technical view

The issue is an unchecked failure return from memblock_phys_alloc_range(). When allocation returns 0, later cleanup can incorrectly free the first 4 MiB of physical memory, causing a crash instead of graceful failure. The source notes CONFIG_PHYSICAL_START=0x100000 as one triggering context.

Likely exposure

Exposure is most relevant to x86 Linux systems running affected kernel versions or downstream products that include them. The bundle lists Linux 5.15, 6.1.141, 6.6.93, 6.12.31, 6.14.9, and 6.15 as affected, with Debian and Siemens references indicating downstream tracking.

Exploitation context

No source in the bundle states active exploitation, and KEV status is false. The described failure depends on a specific early-boot memory condition: less than 4 MiB of contiguous free memory at that allocation point.

Researcher notes

The evidence describes a kernel boot-time crash path, not privilege escalation or remote compromise. Severity, exploitability, and exact fixed release mapping are incomplete in the provided bundle, so validation should rely on vendor backport metadata.

Mitigation direction

  • Review vendor kernel advisories for fixed package versions.
  • Apply applicable Linux stable or distribution kernel updates.
  • Prioritize systems using custom x86 boot configurations or constrained memory layouts.
  • Track Debian and Siemens advisories if those ecosystems are in scope.

Validation and detection

  • Inventory Linux kernel versions across x86 assets.
  • Check whether affected versions listed in the CVE bundle are present.
  • Confirm installed kernels include the referenced stable fixes or vendor backports.
  • Review boot failure reports from constrained-memory or embedded deployments.
Prepared
Confidence
medium
Sources
9

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

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CVE-2025-38071 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
8Source 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.

ADP provider summaries

CVECVE Program Container
siemens-SADPADP container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxa7259df7670240ee03b0cfce8a3e5d3773911e24, a7259df7670240ee03b0cfce8a3e5d3773911e24, a7259df7670240ee03b0cfce8a3e5d3773911e24, a7259df7670240ee03b0cfce8a3e5d3773911e24, a7259df7670240ee03b0cfce8a3e5d3773911e24unaffected
LinuxLinux5.15, 0, 6.1.141, 6.6.93, 6.12.31, 6.14.9, 6.15affected
Weakness

CWE details

No CWE listed

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