LiveActive security incident?Get immediate response
CVE Record

CVE-2026-46164: btrfs: fix double free in create_space_info_sub_group() error path

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix double free in create_space_info_sub_group() error path When kobject_init_and_add() fails, the call chain is: create_space_info_sub_group() -> btrfs_sysfs_add_space_info_type() -> kobject_init_and_add() -> failure -> kobject_put(&sub_group->kobj) -> space_info_release() -> kfree(sub_group) Then control returns to create_space_info_sub_group(), where: btrfs_sysfs_add_space_info_type() returns error -> kfree(sub_group) Thus, sub_group is freed twice. Keep parent->sub_group[index] = NULL for the failure path, but after btrfs_sysfs_add_space_info_type() has called kobject_put(), let the kobject release callback handle the cleanup.

HighCVSS 7Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysishigh

Security readout for executives and security teams

Plain-English summary

A Linux Btrfs error-handling flaw can free the same kernel object twice when creation of a sysfs space-information subgroup fails. This memory corruption may affect confidentiality, integrity, and availability, but exploitation requires local, complex conditions and user interaction according to the supplied CVSS vector.

Executive priority

Treat this as a high-priority kernel maintenance issue on Btrfs systems, especially critical infrastructure. It is not currently supported as an emergency internet-wide threat: the vector is local and complex, and no active exploitation evidence is supplied. Accelerate verified vendor updates while avoiding assumptions from the ambiguous version list.

Technical view

When kobject_init_and_add() fails, btrfs_sysfs_add_space_info_type() calls kobject_put(), whose release callback frees sub_group. create_space_info_sub_group() then frees sub_group again. The kernel fix leaves the failed parent entry null and relies on the kobject release callback for cleanup.

Likely exposure

Exposure is limited to Linux systems running an affected kernel and exercising the relevant Btrfs sysfs failure path. The supplied version data is unusual and includes commit identifiers, overlapping-looking releases, and an affected entry named "0"; validate exact vendor or distribution builds rather than relying on version comparison alone.

Exploitation context

The supplied CVSS is 7.0 with local access, high attack complexity, no privileges, and required user interaction. CISA KEV status is false, and the source bundle provides no evidence of active exploitation or a public exploit. Exact conditions needed to trigger the initiating kobject failure are not documented here.

Researcher notes

The flaw is a double free in a failure-only ownership path. Analysis should focus on reachability of kobject_init_and_add() failure during Btrfs space-info subgroup creation and whether downstream kernels contain an applicable stable commit. The sources do not establish practical exploitability, trigger reliability, affected distributions, or observed attack activity.

Mitigation direction

  • Identify systems using Btrfs and record their exact kernel package and build.
  • Apply a vendor kernel update containing the applicable referenced stable fix.
  • Prioritize Btrfs hosts where kernel compromise or outages would have high business impact.
  • Consult distribution guidance when the supplied upstream version mapping does not clearly match packaged kernels.

Validation and detection

  • Confirm whether Btrfs is enabled or mounted on each potentially affected system.
  • Map the installed kernel build against vendor advisories and the CVE record.
  • Verify the applicable stable fix commit is present in the deployed kernel source or package.
  • After updating, confirm systems boot normally and run the intended vendor kernel.
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

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2026-46164 mapping review

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

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
High
CVSS
7 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/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
0ADP providers
7Source links

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
7CVSS 3.1HighCVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H15.9Linux

Vulnerability scoring details

Base CVSS 3.1 score

7High
CVSS 3.1 vector shape for CVE-2026-46164Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/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.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux64c7ddda83acfbaa0efb381a1928ce908c584607, 0bd151ce4200ca847990e05cca29a76456982ca5, 190d5a7c4fe42b8c9aa46e3336389e7cb10395bb, f92ee31e031c7819126d2febdda0c3e91f5d2eb9, f92ee31e031c7819126d2febdda0c3e91f5d2eb9, f92ee31e031c7819126d2febdda0c3e91f5d2eb9, 6.1.162, 6.6.122, 6.12.67unaffected
LinuxLinux6.16, 0, 6.1.176, 6.6.141, 6.12.90, 6.18.32, 7.0.7, 7.1affected
Weakness

CWE details

No CWE listed

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