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CVE Record

CVE-2024-46686: smb/client: avoid dereferencing rdata=NULL in smb2_new_read_req()

In the Linux kernel, the following vulnerability has been resolved: smb/client: avoid dereferencing rdata=NULL in smb2_new_read_req() This happens when called from SMB2_read() while using rdma and reaching the rdma_readwrite_threshold.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel SMB client bug where a null pointer can be dereferenced during SMB2 reads over RDMA when a size threshold is reached. The public bundle does not provide CVSS, confirmed impact, or active exploitation evidence.

Executive priority

Handle through the normal kernel security patch process, with elevated attention for storage, virtualization, or HPC environments using SMB over RDMA. Do not treat as known exploited based on this bundle alone.

Technical view

The flaw is in smb2_new_read_req(), reachable from SMB2_read() while using RDMA at rdma_readwrite_threshold. The kernel fix avoids dereferencing rdata when it is NULL. The bundle lists Linux kernel versions, commits, and stable patches, but no complete distro fixed-version matrix.

Likely exposure

Relevant systems are Linux hosts acting as SMB/CIFS clients over RDMA. The bundle does not show general SMB servers or non-RDMA SMB clients as affected. Exact package exposure should be mapped through kernel and distro advisories.

Exploitation context

The bundle does not cite public exploitation, and KEV is false. The documented trigger condition is specific: SMB2 read path, RDMA enabled, and the RDMA read-write threshold reached. Practical exploitability is not established in the provided sources.

Researcher notes

Evidence is limited to the CVE description, Linux stable commit references, affected metadata, and a Debian LTS reference. No CVSS, CWE, proof of exploitation, or detailed impact statement is included, so confidence in severity is constrained.

Mitigation direction

  • Review kernel and distribution advisories for the listed stable fixes.
  • Prioritize Linux systems using SMB/CIFS mounts over RDMA.
  • Apply vendor-provided kernel updates when available for affected builds.
  • If patching is delayed, review whether SMB over RDMA is required.

Validation and detection

  • Inventory Linux hosts using SMB/CIFS client functionality.
  • Identify systems configured for SMB Direct or RDMA-backed SMB access.
  • Compare running kernel builds against vendor fixed-version guidance.
  • Confirm Debian LTS or other distro updates are applied where relevant.
Prepared
Confidence
medium
Sources
7

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.

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CVE-2024-46686 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
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
6Source links

SSVC decision data

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

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
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinuxedf38e9f4269591d26b3783c0b348c9345580c3c, a6559cc1d35d3eeafb0296aca347b2f745a28a74, a6559cc1d35d3eeafb0296aca347b2f745a28a74, a6559cc1d35d3eeafb0296aca347b2f745a28a74, 74ab77137c99438626f4eb8134d8e26204bb5b64, 6.1.16, 6.2.3unaffected
LinuxLinux6.3, 0, 6.1.108, 6.6.49, 6.10.8, 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.