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CVE Record

CVE-2024-56756: nvme-pci: fix freeing of the HMB descriptor table

In the Linux kernel, the following vulnerability has been resolved: nvme-pci: fix freeing of the HMB descriptor table The HMB descriptor table is sized to the maximum number of descriptors that could be used for a given device, but __nvme_alloc_host_mem could break out of the loop earlier on memory allocation failure and end up using less descriptors than planned for, which leads to an incorrect size passed to dma_free_coherent. In practice this was not showing up because the number of descriptors tends to be low and the dma coherent allocator always allocates and frees at least a page.

MediumCVSS 5.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2024-56756 is a Linux kernel nvme-pci flaw that can cause availability impact when host memory buffer allocation fails partway through. It is local, not remote, and requires a low-privileged local context. The practical impact is likely system instability or crash, not data theft or tampering.

Executive priority

Schedule remediation in the normal kernel patch cycle, with faster handling for shared servers, virtualization hosts, and storage-heavy systems. This is not presented as actively exploited, but availability impact can still affect business continuity.

Technical view

The nvme-pci driver can allocate fewer HMB descriptors than planned, then pass an incorrect size to dma_free_coherent when freeing the HMB descriptor table. The CVSS vector is local, low complexity, low privileges, no user interaction, and high availability impact. The source notes this rarely appeared in practice because allocations typically round to at least a page.

Likely exposure

Exposure is most relevant to Linux systems using NVMe PCI storage where affected kernel versions or unpatched vendor kernels are deployed. The source bundle lists Linux as affected and references upstream stable commits plus Debian LTS advisories. Confirm exact exposure through your distribution’s kernel package status.

Exploitation context

The source bundle does not show KEV listing or active exploitation. The CVSS vector indicates local access with low privileges is required. Available evidence supports treating this as a local availability issue rather than a remote compromise path.

Researcher notes

Focus analysis on nvme-pci HMB allocation and cleanup paths. The key condition is early allocation-loop exit leading to mismatched size during dma_free_coherent. Public evidence is limited to the CVE record, upstream stable fixes, and Debian LTS references.

Mitigation direction

  • Apply the relevant Linux kernel update from your OS vendor.
  • Use upstream stable kernel commits only through normal kernel maintenance processes.
  • Review Debian LTS advisories if running affected Debian LTS systems.
  • Prioritize patching multi-tenant Linux hosts with NVMe storage.
  • If patch status is unclear, check vendor guidance before applying workarounds.

Validation and detection

  • Inventory Linux hosts and record running kernel versions.
  • Compare kernel packages against vendor advisories for CVE-2024-56756.
  • Identify systems using NVMe PCI storage drivers.
  • Confirm whether vendor kernels include the referenced stable fixes.
  • Monitor local crash, kernel, and storage-driver logs for instability.
Prepared
Confidence
high
Sources
12

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-2024-56756 mapping review

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

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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
2ADP providers
11Source 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
5.5CVSS 3.1MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

5.5Medium
CVSS 3.1 vector shape for CVE-2024-56756Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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
cvssV3_1other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux87ad72a59a38d1df217cfd95bc222a2edfe5d399, 87ad72a59a38d1df217cfd95bc222a2edfe5d399, 87ad72a59a38d1df217cfd95bc222a2edfe5d399, 87ad72a59a38d1df217cfd95bc222a2edfe5d399, 87ad72a59a38d1df217cfd95bc222a2edfe5d399, 87ad72a59a38d1df217cfd95bc222a2edfe5d399, 87ad72a59a38d1df217cfd95bc222a2edfe5d399, 87ad72a59a38d1df217cfd95bc222a2edfe5d399unaffected
LinuxLinux4.13, 0, 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.64, 6.11.11, 6.12.2, 6.13affected
Weakness

CWE details

No CWE listed

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