LiveActive security incident?Get immediate response
CVE Record

CVE-2025-71269: btrfs: do not free data reservation in fallback from inline due to -ENOSPC

In the Linux kernel, the following vulnerability has been resolved: btrfs: do not free data reservation in fallback from inline due to -ENOSPC If we fail to create an inline extent due to -ENOSPC, we will attempt to go through the normal COW path, reserve an extent, create an ordered extent, etc. However we were always freeing the reserved qgroup data, which is wrong since we will use data. Fix this by freeing the reserved qgroup data in __cow_file_range_inline() only if we are not doing the fallback (ret is <= 0).

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel btrfs bug involving storage accounting during a low-space fallback path. The public record describes a kernel fix but does not provide CVSS, impact class, or real-world exploitation evidence. Treat it as an exposure-management item for Linux systems using btrfs, especially where quota groups may be relevant.

Executive priority

Monitor and patch through normal kernel maintenance unless your environment relies heavily on btrfs. There is insufficient public evidence to rank this as emergency work, but kernel filesystem defects deserve timely remediation because impact details may be clarified later.

Technical view

When btrfs cannot create an inline extent because of ENOSPC, it falls back to the normal copy-on-write path. The vulnerable logic still freed reserved qgroup data even though the fallback would use data. The fix changes reservation freeing so it does not occur during that fallback. The source does not state concrete security impact.

Likely exposure

Potential exposure is limited to Linux kernels in the affected version data and systems using btrfs paths implicated by qgroup data reservation. The bundle lists Linux kernel versions but gives incomplete product detail and no distro mapping, so validate against vendor kernel packages.

Exploitation context

The source bundle does not report active exploitation, and KEV is false. It also does not provide exploitability details, required privileges, attack surface, or attacker workflow. Do not assume remote exploitation or confirmed abuse from the available evidence.

Researcher notes

The record is source-code focused and lacks CVSS, CWE, impact statement, exploit requirements, and distro package mapping. Analysis should center on the btrfs inline extent ENOSPC fallback and qgroup reservation handling. Avoid extrapolating beyond the stated reservation-freeing bug and stable fix references.

Mitigation direction

  • Check Linux distribution advisories for CVE-2025-71269 package status.
  • Update affected Linux kernels when vendor-supported fixes are available.
  • Prioritize hosts using btrfs or btrfs quota-group features.
  • Track the linked stable kernel commits for backport confirmation.
  • If no vendor fix exists, follow vendor guidance rather than improvising workarounds.

Validation and detection

  • Inventory Linux kernel versions across btrfs-capable systems.
  • Identify systems actively using btrfs filesystems.
  • Check whether btrfs quota groups are enabled where applicable.
  • Compare deployed vendor kernels with fixed stable commit references.
  • Confirm scanner findings against distro advisories and package changelogs.
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.

cve · low confidence lookup

CVE-2025-71269 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
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
LinuxLinux94ed938aba557aa798acf496f09afb289b619fcd, 94ed938aba557aa798acf496f09afb289b619fcd, 94ed938aba557aa798acf496f09afb289b619fcd, 94ed938aba557aa798acf496f09afb289b619fcd, 94ed938aba557aa798acf496f09afb289b619fcdunaffected
LinuxLinux4.4, 0, 6.1.168, 6.6.134, 6.12.81, 6.18.10, 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.