dbcve.org
Linux KernelOperating system · Linux

CVE-2024-23850

MEDIUM · 5.5 CVSS v3.1 Published 2024-01-23
Fix available
A fix is available. Upgrade to after 6.7.1 or later.
See remediation →
57/100
Remediation priority · Elevated
Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In btrfs_get_root_ref in fs/btrfs/disk-io.c in the Linux kernel through 6.7.1, there can be an assertion failure and crash because a subvolume can be read out too soon after its root item is inserted upon subvolume creation.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A race condition in btrfs_get_root_ref in Linux kernel versions through 6.7.1 allows a subvolume to be accessed before its root item is fully initialized during creation. This triggers an assertion failure and kernel crash (likely a panic). The vulnerability exists in the BTRFS filesystem's disk I/O path, specifically in the subvolume creation sequence where insufficient synchronization permits premature access.

MitigationUpgrade the Linux kernel to a version past 6.7.1 that contains the fix for this race condition. If immediate upgrade is not feasible, avoid creating new BTRFS subvolumes on affected systems until the kernel can be patched, as the vulnerability is triggered during subvolume creation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Linux KernelOperating system
Affected:<= 6.7.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check the running Linux kernel version
    Run `uname -r` or `cat /proc/version` to obtain the kernel version string
    Affected if The kernel version is 6.7.1 or earlier (versions 6.7.1 and below are affected)
  2. Verify BTRFS filesystem is in use
    Run `mount | grep -i btrfs` or check `df -T` output to see if any mounted filesystems are BTRFS type
    Affected if Any BTRFS filesystem is mounted on the system
  3. Confirm BTRFS kernel module is loaded
    Run `lsmod | grep btrfs` or check `cat /proc/filesystems` for btrfs entry
    Affected if The btrfs module is loaded or available (required for the vulnerability to be triggerable)
  4. Identify BTRFS subvolume usage
    Run `btrfs subvolume list /mountpoint` for each BTRFS mount point to list existing subvolumes
    Affected if BTRFS subvolumes exist, indicating the system uses subvolume functionality and could trigger the flaw during new subvolume creation

A system is affected if it runs a Linux kernel at version 6.7.1 or earlier, uses BTRFS filesystems, and creates new subvolumes triggers the race condition in btrfs_get_root_ref.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 6.7.1
Interim mitigation

Upgrade the Linux kernel to a version past 6.7.1 that contains the fix for this race condition. If immediate upgrade is not feasible, avoid creating new BTRFS subvolumes on affected systems until the kernel can be patched, as the vulnerability is triggered during subvolume creation.

Recommended fix Moderate confidence

Linux Kernel 6.7.2 or later (or distribution-specific kernel update containing the CVE-2024-23850 fix)

  1. Upgrade Linux kernel to version 6.7.2 or later, which contains the fix for the btrfs subvolume assertion failure vulnerability
  2. If using a distribution-specific kernel, apply the distribution's security update that addresses CVE-2024-23850
  3. After kernel update, reboot the system to load the patched kernel
  4. Verify the running kernel version with 'uname -r' to confirm the fix is applied
Caveat Kernel upgrades may require system reboot and could introduce compatibility issues with out-of-tree kernel modules or older system utilities

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Linux Kernel Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA6.0 h
30.0 hours of engineering $5,120
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-23850 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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