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NVD / CVE Program· CNA Linux

CVE-2024-50273: btrfs: reinitialize delayed ref list after deleting it from the list

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: 0.29% (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 2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6, 2fd0948a483e9cb2d669c7199bc620a21c97673d, 50a3933760b427759afdd23156a7280a19357a92; azl3 kernel 6.6.57.1-7 on Azure Linux 3.0 6.6.64.2-1; azl3 kernel 6.6.64.2-1 on Azure Linux 3.0 6.6.64.2-1.
  • Severity is disputed: the assigning authority (CNA) scores it 7.8, NVD 5.5.

Low priority for now. Upgrade to Linux Linux 2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6, 2fd0948a483e9cb2d669c7199bc620a21c97673d, 50a3933760b427759afdd23156a7280a19357a92; azl3 kernel 6.6.57.1-7 on Azure Linux 3.0 6.6.64.2-1; azl3 kernel 6.6.64.2-1 on Azure Linux 3.0 6.6.64.2-1 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: reinitialize delayed ref list after deleting it from the list At insert_delayed_ref() if we need to update the action of an existing ref to BTRFS_DROP_DELAYED_REF, we delete the ref from its ref head's ref_add_list using list_del(), which leaves the ref's add_list member not reinitialized, as list_del() sets the next and prev members of the list to LIST_POISON1 and LIST_POISON2, respectively. If later we end up calling drop_delayed_ref() against the ref, which can happen during merging or when destroying delayed refs due to a transaction abort, we can trigger a crash since at drop_delayed_ref() we call list_empty() against the ref's add_list, which returns false since the list was not reinitialized after the list_del() and as a consequence we call list_del() again at drop_delayed_ref(). This results in an invalid list access since the next and prev members are set to poison pointers, resulting in a splat if CONFIG_LIST_HARDENED and CONFIG_DEBUG_LIST are set or invalid poison pointer dereferences otherwise. So fix this by deleting from the list with list_del_init() instead.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Nov 18, 2024
Updated
Aug 5, 2026
EPSS
0.2% · 21th percentile

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.

CNA vs NVD score

NVD
5.5
CNA · Linux
7.8
2.3 point gap

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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.

Follow CVE-2024-50273

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 kernel4.10 and later · before 4.19.324
  • linux linux kernel4.20 and later · before 5.4.286
  • linux linux kernel5.5 and later · before 5.10.230
  • linux linux kernel5.11 and later · before 5.15.172
  • linux linux kernel5.16 and later · before 6.1.117
  • linux linux kernel6.2 and later · before 6.6.61
  • linux linux kernel6.7 and later · before 6.11.8
  • linux linux kernel6.12

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

    • 4.10affected
    • 1d57ee941692d0cc928526e21a1557b2ae3e11db and later · before 2fd0948a483e9cb2d669c7199bc620a21c97673daffected · git
    • 1d57ee941692d0cc928526e21a1557b2ae3e11db and later · before 93c5b8decc0ef39ba84f4211d2db6da0a4aefbebaffected · git
    • 1d57ee941692d0cc928526e21a1557b2ae3e11db and later · before bf0b0c6d159767c0d1c21f793950d78486690ee0affected · git
    • 1d57ee941692d0cc928526e21a1557b2ae3e11db and later · before c24fa427fc0ae827b2a3a07f13738cbf82c3f851affected · git
    • 1d57ee941692d0cc928526e21a1557b2ae3e11db and later · before 2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6affected · git
    • 1d57ee941692d0cc928526e21a1557b2ae3e11db and later · before f04be6d68f715c1473a8422fc0460f57b5e99931affected · git
    • 1d57ee941692d0cc928526e21a1557b2ae3e11db and later · before 50a3933760b427759afdd23156a7280a19357a92affected · git
    • 1d57ee941692d0cc928526e21a1557b2ae3e11db and later · before c9a75ec45f1111ef530ab186c2a7684d0a0c9245affected · git
    • before 4.10not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.119-16.1.119-1
Debian:13linuxbefore 6.11.9-16.11.9-1

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-2024-50271Nov 18, 2024 · signal: restore the override_rlimit logic
    22Monitor
  • ← EarlierCVE-2024-50272Nov 18, 2024 · filemap: Fix bounds checking in filemap_read()
    22Monitor
  • Later →CVE-2024-50274Nov 18, 2024 · idpf: avoid vport access in idpf_get_link_ksettings
    31Monitor

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 Linux2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6Vendor (CNA)
Linux Linux2fd0948a483e9cb2d669c7199bc620a21c97673dVendor (CNA)
Linux Linux50a3933760b427759afdd23156a7280a19357a92Vendor (CNA)
Linux Linux93c5b8decc0ef39ba84f4211d2db6da0a4aefbebVendor (CNA)
Linux Linuxbf0b0c6d159767c0d1c21f793950d78486690ee0Vendor (CNA)
Linux Linuxc24fa427fc0ae827b2a3a07f13738cbf82c3f851Vendor (CNA)
Linux Linuxc9a75ec45f1111ef530ab186c2a7684d0a0c9245Vendor (CNA)
Linux Linuxf04be6d68f715c1473a8422fc0460f57b5e99931Vendor (CNA)
azl3 kernel 6.6.57.1-7 on Azure Linux 3.06.6.64.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.64.2-1 on Azure Linux 3.06.6.64.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.167.1-2 on CBL Mariner 2.05.15.173.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.167.1-2 on CBL-Mariner 2.05.15.173.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
cbl2 kernel 5.15.173.1-1 on CBL Mariner 2.05.15.173.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.119-1 · 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.

  • CVE-2024-503021 days apartHID: core: zero-initialize the report bufferKEV
    52Plan
  • CVE-2024-4768528 days apartnetfilter: nf_reject_ipv6: fix nf_reject_ip6_tcphdr_put()
    36Monitor
  • CVE-2026-43139534 days apartxfrm6: fix uninitialized saddr in xfrm6_get_saddr()
    34Monitor
  • CVE-2026-43291536 days apartnet: nfc: nci: Fix parameter validation for packet data
    33Monitor
  • CVE-2024-5014311 days apartudf: fix uninit-value use in udf_get_fileshortad
    31Monitor
  • CVE-2024-36898172 days apartgpiolib: cdev: fix uninitialised kfifo
    31Monitor

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).

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)

CWE-908 · Use of Uninitialized Resource

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