---
id: CVE-2026-97415
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  btrfs: tree-checker: validate names in ROOT_REF and ROOT_BACKREF

  ROOT_REF and ROOT_BACKREF items contain a struct btrfs_root_ref followed
  by the subvolume name
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  btrfs: tree-checker: validate names in ROOT_REF and ROOT_BACKREF

  ROOT_REF and ROOT_BACKREF items contain a struct btrfs_root_ref followed
  by the subvolume name. Severa…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= b64ec075bded2b30bcd90af5aa5256d2237c885d <
    1370badf6b823ce3cde39a65f46f9e5dc7b4bf43
  - >-
    Linux >= b64ec075bded2b30bcd90af5aa5256d2237c885d <
    ba6c4fc662853f6662e4db060cf88ee994053e21
  - >-
    Linux >= b64ec075bded2b30bcd90af5aa5256d2237c885d <
    9154542070ca7eadb3c764a882f39a127677854b
  - >-
    Linux >= b64ec075bded2b30bcd90af5aa5256d2237c885d <
    74f577c722c99248d804eca18e7de7c5e47549d7
  - >-
    Linux >= b64ec075bded2b30bcd90af5aa5256d2237c885d <
    0af37c217edf15fa21dac1c40822086df356c6bb
  - Linux 4.18
published: '2026-09-24'
updated: '2026-10-03'
sourceUpdated: '2026-10-03T11:17:53.457'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97415'
references:
  - url: 'https://git.kernel.org/stable/c/0af37c217edf15fa21dac1c40822086df356c6bb'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1370badf6b823ce3cde39a65f46f9e5dc7b4bf43'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/74f577c722c99248d804eca18e7de7c5e47549d7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9154542070ca7eadb3c764a882f39a127677854b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ba6c4fc662853f6662e4db060cf88ee994053e21'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
epss: 0.00131
epssPercentile: 0.02702
ingestedAt: '2026-09-24T16:47:15.886Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

btrfs: tree-checker: validate names in ROOT_REF and ROOT_BACKREF

ROOT_REF and ROOT_BACKREF items contain a struct btrfs_root_ref followed
by the subvolume name. Several readers assume that this layout is already
valid and then use the on-disk name length directly. A corrupted item can
therefore make those readers address bytes outside the item, and
BTRFS_IOC_GET_SUBVOL_INFO can copy too many bytes into its fixed-size UAPI
name buffer.

Validate ROOT_REF and ROOT_BACKREF items in tree-checker before any reader
uses them. Reject records that do not contain a non-empty name, whose
name_len does not exactly describe the remaining item payload, or whose
name exceeds BTRFS_NAME_LEN.

For BTRFS_IOC_GET_SUBVOL_INFO, copy only the validated on-disk name_len
instead of deriving the copy length from the item size. The ioctl result is
zeroed when allocated. That leaves the existing trailing zero byte
untouched.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.