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CVE Record

CVE-2025-71082: Bluetooth: btusb: revert use of devm_kzalloc in btusb

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: btusb: revert use of devm_kzalloc in btusb This reverts commit 98921dbd00c4e ("Bluetooth: Use devm_kzalloc in btusb.c file"). In btusb_probe(), we use devm_kzalloc() to allocate the btusb data. This ties the lifetime of all the btusb data to the binding of a driver to one interface, INTF. In a driver that binds to other interfaces, ISOC and DIAG, this is an accident waiting to happen. The issue is revealed in btusb_disconnect(), where calling usb_driver_release_interface(&btusb_driver, data->intf) will have devm free the data that is also being used by the other interfaces of the driver that may not be released yet. To fix this, revert the use of devm and go back to freeing memory explicitly.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2025-71082 is a Linux kernel Bluetooth USB driver memory-lifetime bug. The driver could free shared btusb data while other related USB interfaces still use it. Business urgency depends on whether affected Linux kernels with USB Bluetooth support are deployed. No public source in the bundle confirms active exploitation.

Executive priority

Treat as a kernel maintenance priority, not an emergency, unless critical systems depend on USB Bluetooth and cannot be patched. The absence of CVSS and exploitation evidence lowers urgency, but kernel memory bugs should be addressed through normal accelerated patch cycles.

Technical view

The Linux btusb driver used devm_kzalloc in btusb_probe, tying btusb data lifetime to one interface binding. During btusb_disconnect, usb_driver_release_interface could trigger devm cleanup while ISOC or DIAG interfaces still referenced the same data. Kernel stable fixes revert that allocation change and return to explicit memory freeing.

Likely exposure

Exposure is most relevant to Linux systems running affected kernel builds with the btusb Bluetooth USB driver. The CVE data lists Linux as affected and links multiple stable kernel fixes. Distribution kernels may backport fixes, so version strings alone may be insufficient.

Exploitation context

The provided sources describe a kernel driver memory-use condition during USB Bluetooth interface disconnect handling. They do not provide an attacker model, exploitability assessment, CVSS score, or evidence of exploitation. CISA KEV status in the bundle is false.

Researcher notes

Key evidence is the upstream fix rationale, not a detailed security analysis. The record lacks CVSS, CWE, attacker prerequisites, and impact details. Focus validation on whether the revert commits are present in the running kernel source or vendor backport.

Mitigation direction

  • Update to a vendor kernel incorporating the linked Linux stable fixes.
  • Prioritize systems using USB Bluetooth or loading the btusb driver.
  • If patch timing is unclear, check Linux distribution advisories for backport status.
  • Avoid relying on upstream version numbers without confirming distribution patch backports.

Validation and detection

  • Inventory Linux kernel versions across fleets.
  • Check whether btusb is present or loaded on relevant systems.
  • Confirm vendor kernel changelogs include the CVE or linked stable commits.
  • Verify patched test systems still support required Bluetooth hardware.
Prepared
Confidence
medium
Sources
8

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-2025-71082 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
1ADP providers
7Source links

SSVC decision data

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

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

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux98921dbd00c4e2e4bdd56423cb5edf98d57b45f7, 98921dbd00c4e2e4bdd56423cb5edf98d57b45f7, 98921dbd00c4e2e4bdd56423cb5edf98d57b45f7, 98921dbd00c4e2e4bdd56423cb5edf98d57b45f7, 98921dbd00c4e2e4bdd56423cb5edf98d57b45f7, 98921dbd00c4e2e4bdd56423cb5edf98d57b45f7unaffected
LinuxLinux3.7, 0, 5.15.198, 6.1.160, 6.6.120, 6.12.64, 6.18.4, 6.19affected
Weakness

CWE details

No CWE listed

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