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CVE Record

CVE-2025-40036: misc: fastrpc: fix possible map leak in fastrpc_put_args

In the Linux kernel, the following vulnerability has been resolved: misc: fastrpc: fix possible map leak in fastrpc_put_args copy_to_user() failure would cause an early return without cleaning up the fdlist, which has been updated by the DSP. This could lead to map leak. Fix this by redirecting to a cleanup path on failure, ensuring that all mapped buffers are properly released before returning.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

CVE-2025-40036 is a Linux kernel FastRPC cleanup flaw. If copying results back to user space fails, mapped buffers may not be released, causing a map leak. The available sources do not provide CVSS, confirmed impact scope, or active exploitation evidence.

Executive priority

Treat as a kernel maintenance item until severity is clarified. Prioritize patch validation on systems that use FastRPC, embedded Linux, or DSP-related functionality, but do not escalate as actively exploited based on current sources.

Technical view

The flaw is in fastrpc_put_args. A copy_to_user failure could return early after the DSP updated fdlist state, bypassing cleanup for mapped buffers. Linux stable commits fix this by routing failure handling through a cleanup path before returning.

Likely exposure

Exposure appears limited to Linux systems using affected kernel builds where the misc FastRPC driver is present and reachable. The bundle lists Linux as affected, but does not provide complete, plain-language version ranges or distribution advisories.

Exploitation context

The source bundle shows no KEV listing and no cited evidence of exploitation in the wild. It describes a cleanup failure leading to a map leak, not a complete exploit chain or remotely exploitable condition.

Researcher notes

Key evidence is narrow: a copy_to_user error path skipped fdlist cleanup after DSP interaction. The public bundle lacks CVSS, CWE, exploitability analysis, and distribution-specific affected ranges, so impact assessment requires vendor kernel mapping.

Mitigation direction

  • Review Linux vendor or distribution advisories for CVE-2025-40036 applicability.
  • Update to a kernel build containing the referenced stable fixes.
  • Prioritize systems using FastRPC or DSP-related workloads.
  • If updates are unavailable, follow vendor guidance for limiting affected driver exposure.

Validation and detection

  • Inventory running kernel versions across Linux assets.
  • Check whether FastRPC support is enabled or loaded on relevant systems.
  • Compare installed kernels against vendor advisories and stable fix commits.
  • Confirm patched kernels include the fastrpc_put_args cleanup change.
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

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CVE-2025-40036 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
6Source 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
LinuxLinuxc68cfb718c8f97b7f7a50ed66be5feb42d0c8988, c68cfb718c8f97b7f7a50ed66be5feb42d0c8988, c68cfb718c8f97b7f7a50ed66be5feb42d0c8988, c68cfb718c8f97b7f7a50ed66be5feb42d0c8988, c68cfb718c8f97b7f7a50ed66be5feb42d0c8988unaffected
LinuxLinux5.1, 0, 6.1.156, 6.6.112, 6.12.53, 6.17.3, 6.18affected
Weakness

CWE details

No CWE listed

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