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NVD / CVE Program· CNA Linux

CVE-2024-46840: btrfs: clean up our handling of refs == 0 in snapshot delete

Noroxi assessment

Priority: Monitor (action score 22/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.26% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 03804641ec2d0da4fa088ad21c88e703d151ce16, 71291aa7246645ef622621934d2067400380645e, 728d4d045b628e006b48a448f3326a7194c88d32; Azure Linux 3.0 ARM 6.6.51.1-5; Azure Linux 3.0 x64 6.6.51.1-5.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 03804641ec2d0da4fa088ad21c88e703d151ce16, 71291aa7246645ef622621934d2067400380645e, 728d4d045b628e006b48a448f3326a7194c88d32; Azure Linux 3.0 ARM 6.6.51.1-5; Azure Linux 3.0 x64 6.6.51.1-5 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: btrfs: clean up our handling of refs == 0 in snapshot delete In reada we BUG_ON(refs == 0), which could be unkind since we aren't holding a lock on the extent leaf and thus could get a transient incorrect answer. In walk_down_proc we also BUG_ON(refs == 0), which could happen if we have extent tree corruption. Change that to return -EUCLEAN. In do_walk_down() we catch this case and handle it correctly, however we return -EIO, which -EUCLEAN is a more appropriate error code. Finally in walk_up_proc we have the same BUG_ON(refs == 0), so convert that to proper error handling. Also adjust the error message so we can actually do something with the information.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Sep 27, 2024
Updated
Jun 17, 2026
EPSS
0.2% · 17th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernelbefore 4.19.322
  • linux linux kernel4.20 and later · before 5.4.284
  • linux linux kernel5.5 and later · before 5.10.226
  • linux linux kernel5.11 and later · before 5.15.167
  • linux linux kernel5.16 and later · before 6.1.110
  • linux linux kernel6.2 and later · before 6.6.51
  • linux linux kernel6.7 and later · before 6.10.10

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 2.6.31affected
    • 2c47e605a91dde6b0514f689645e7ab336c8592a and later · before c847b28a799733b04574060ab9d00f215970627daffected · git
    • 2c47e605a91dde6b0514f689645e7ab336c8592a and later · before 71291aa7246645ef622621934d2067400380645eaffected · git
    • 2c47e605a91dde6b0514f689645e7ab336c8592a and later · before c60676b81fab456b672796830f6d8057058f029caffected · git
    • 2c47e605a91dde6b0514f689645e7ab336c8592a and later · before 728d4d045b628e006b48a448f3326a7194c88d32affected · git
    • 2c47e605a91dde6b0514f689645e7ab336c8592a and later · before 9cc887ac24b7a0598f4042ae9af6b9a33072f75baffected · git
    • 2c47e605a91dde6b0514f689645e7ab336c8592a and later · before 7d1df13bf078ffebfedd361d714ff6cee1ff01b9affected · git
    • 2c47e605a91dde6b0514f689645e7ab336c8592a and later · before 03804641ec2d0da4fa088ad21c88e703d151ce16affected · git
    • 2c47e605a91dde6b0514f689645e7ab336c8592a and later · before b8ccef048354074a548f108e51d0557d6adfd3a3affected · git
    • before 2.6.31not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.112-16.1.112-1
Debian:13linuxbefore 6.10.11-16.10.11-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2024-46837Sep 27, 2024 · drm/panthor: Restrict high priorities on group_create
    22Monitor
  • ← EarlierCVE-2024-46838Sep 27, 2024 · userfaultfd: don't BUG_ON() if khugepaged yanks our page table
    22Monitor
  • Later →CVE-2024-46841Sep 27, 2024 · btrfs: don't BUG_ON on ENOMEM from btrfs_lookup_extent_info() in walk_down_proc()
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux03804641ec2d0da4fa088ad21c88e703d151ce16Vendor (CNA)
Linux Linux71291aa7246645ef622621934d2067400380645eVendor (CNA)
Linux Linux728d4d045b628e006b48a448f3326a7194c88d32Vendor (CNA)
Linux Linux7d1df13bf078ffebfedd361d714ff6cee1ff01b9Vendor (CNA)
Linux Linux9cc887ac24b7a0598f4042ae9af6b9a33072f75bVendor (CNA)
Linux Linuxb8ccef048354074a548f108e51d0557d6adfd3a3Vendor (CNA)
Linux Linuxc60676b81fab456b672796830f6d8057058f029cVendor (CNA)
Linux Linuxc847b28a799733b04574060ab9d00f215970627dVendor (CNA)
Azure Linux 3.0 ARM6.6.51.1-5 · kernelMicrosoft (MSRC)
Azure Linux 3.0 x646.6.51.1-5 · kernelMicrosoft (MSRC)
CBL Mariner 2.0 ARM5.15.167.1-1 · kernelMicrosoft (MSRC)
CBL Mariner 2.0 x645.15.167.1-1 · kernelMicrosoft (MSRC)
debian:linux6.1.112-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

—

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (9 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records