---
id: CVE-2021-3739
title: >-
  A NULL pointer dereference flaw was found in the btrfs_rm_device function in
  fs/btrfs/volumes.c in the Linux Kernel, where triggering the bug requires
  ‘CAP_SYS_ADMIN’
summary: >-
  A NULL pointer dereference flaw was found in the btrfs_rm_device function in
  fs/btrfs/volumes.c in the Linux Kernel, where triggering the bug requires
  ‘CAP_SYS_ADMIN’. This flaw allows a local attacker to crash the system or leak
  kernel …
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'
cwe:
  - CWE-476
  - CWE-476
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 4.20, < 5.4.144'
  - 'linux_kernel >= 5.5, < 5.10.62'
  - 'linux_kernel >= 5.11, < 5.13.14'
  - 'linux_kernel >= 5.14, < 5.14.1'
  - fedora = 34
  - h300s_firmware
  - h500s_firmware
  - h700s_firmware
  - h300e_firmware
  - h500e_firmware
  - h700e_firmware
  - h410s_firmware
  - h410c_firmware
patched:
  - linux_kernel 5.14.1
published: '2022-03-10'
updated: '2026-09-01'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-3739'
references:
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=1997958'
    label: secalert@redhat.com
  - url: >-
      https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e4571b8c5e9ffa1e85c0c671995bd4dcc5c75091
    label: secalert@redhat.com
  - url: >-
      https://github.com/torvalds/linux/commit/e4571b8c5e9ffa1e85c0c671995bd4dcc5c75091
    label: secalert@redhat.com
  - url: 'https://security.netapp.com/advisory/ntap-20220407-0006/'
    label: secalert@redhat.com
  - url: 'https://ubuntu.com/security/CVE-2021-3739'
    label: secalert@redhat.com
  - url: 'https://www.openwall.com/lists/oss-security/2021/08/25/3'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=1997958'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e4571b8c5e9ffa1e85c0c671995bd4dcc5c75091
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://github.com/torvalds/linux/commit/e4571b8c5e9ffa1e85c0c671995bd4dcc5c75091
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20220407-0006/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://ubuntu.com/security/CVE-2021-3739'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.openwall.com/lists/oss-security/2021/08/25/3'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00616
epssPercentile: 0.47829
ingestedAt: '2026-09-01T18:30:36.501Z'
---

## Overview

A NULL pointer dereference flaw was found in the btrfs_rm_device function in fs/btrfs/volumes.c in the Linux Kernel, where triggering the bug requires ‘CAP_SYS_ADMIN’. This flaw allows a local attacker to crash the system or leak kernel internal information. The highest threat from this vulnerability is to system availability.

## Affected

- `linux_kernel >= 4.20, < 5.4.144`
- `linux_kernel >= 5.5, < 5.10.62`
- `linux_kernel >= 5.11, < 5.13.14`
- `linux_kernel >= 5.14, < 5.14.1`
- `fedora = 34`
- `h300s_firmware`
- `h500s_firmware`
- `h700s_firmware`
- `h300e_firmware`
- `h500e_firmware`
- `h700e_firmware`
- `h410s_firmware`
- `h410c_firmware`

## Remediation

Upgrade past the affected range:

- `linux_kernel 5.14.1`