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  4. CVE 2025 21879 btrfs fix use after free on inode when scanning
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Back to active CVEs
High · CVSS 7.8CVE-2025-21879

btrfs: fix use-after-free on inode when scanning root during em shrinkingCVE-2025-21879

Answer in brief

CVE-2025-21879 records a High severity (CVSS 7.8) vulnerability in btrfs: fix use-after-free on inode when scanning root during em shrinking. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Mar 27, 2025Updated Aug 5, 2026Source checked Nov 3, 2026First seen by HOL Aug 5, 2026Material review Aug 5, 2026
Upstream Advisory

Key facts

Risk
High · CVSS 7.8
Exploitation
Not marked as known exploited
Affected software
2 mapped packages or products
Fix availability
Available

Why this deserves its current priority

CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
PackageAffected rangeFixed version
Linux/Linuxgeneric>=fef55c4d9c9c22264d2b2ceae1e26922cb6129a5 <07836bc18f4ae42da4e922244f4685561c18755e || >=1020443840569535f6025a855958f07ea3eebf71 <5e79d26014f9386387575b9ed60d342057cee49b || >=1020443840569535f6025a855958f07ea3eebf71 <59f37036bb7ab3d554c24abc856aabca0112641407836bc18f4ae42da4e922244f4685561c18755e, 5e79d26014f9386387575b9ed60d342057cee49b, 59f37036bb7ab3d554c24abc856aabca01126414
Linux/Linuxgeneric6.13Not reported

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
  2. 2Review the reported fix. Update Linux/Linux to 07836bc18f4ae42da4e922244f4685561c18755e if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

  1. Published upstream

    Mar 27, 2025

    Evidence: source:cvelist:source_dates:source-dates:record

  2. Source modified

    Aug 5, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  3. First seen by HOL

    Aug 5, 2026

Sources and claim methodology

  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
  • Source referencegit.kernel.org
Upstream source description

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix use-after-free on inode when scanning root during em shrinking At btrfs_scan_root() we are accessing the inode's root (and fs_info) in a call to btrfs_fs_closing() after we have scheduled the inode for a delayed iput, and that can result in a use-after-free on the inode in case the cleaner kthread does the iput before we dereference the inode in the call to btrfs_fs_closing(). Fix this by using the fs_info stored already in a local variable instead of doing inode->root->fs_info.

Quoted source text, attributed separately from HOL analysis.

Related CVEs

  • Use-after-free vulnerability in GitHub Enterprise Server allowed remote code execution in the Git serviceAlso CWE-416

Record context

Vulnerability class
Memory Corruption
EPSS
Not reported
CWE IDs
CWE-416
Source
CVE List V5
Source checked
Nov 3, 2026
References
3 linked sources
Open source record