Skip to content
Fencer Intel
medium 5.5

CVE-2024-44963 json

btrfs: do not BUG_ON() when freeing tree block after error

published 2y ago modified 12d ago also EUVD-2024-41166

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

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

btrfs: do not BUG_ON() when freeing tree block after error

When freeing a tree block, at btrfs_free_tree_block(), if we fail to create a delayed reference we don't deal with the error and just do a BUG_ON(). The error most likely to happen is -ENOMEM, and we have a comment mentioning that only -ENOMEM can happen, but that is not true, because in case qgroups are enabled any error returned from btrfs_qgroup_trace_extent_post() (can be -EUCLEAN or anything returned from btrfs_search_slot() for example) can be propagated back to btrfs_free_tree_block().

So stop doing a BUG_ON() and return the error to the callers and make them abort the transaction to prevent leaking space. Syzbot was triggering this, likely due to memory allocation failure injection.

Patch / fix

  • Linux Linux 6.1.191, 6.6.64, 6.10.5, 6.11
  • linux Debian 14, Debian 13 6.10.6-1

debian advisories DEBIAN-CVE-2024-44963

  • linux Ubuntu 24.04 LTS 6.8.0-50.51
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1020.22
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1019.21
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1015.19
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1017.17
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1020.23
  • linux-gkeop Ubuntu 24.04 LTS 6.8.0-1002.4
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1016.18

ubuntu advisories UBUNTU-CVE-2024-44963

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.49.1
  • kernel-syms-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.49.1
  • kernel-rt_debug Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.49.1
  • kernel-source-rt Real Time Module 15 SP6, openSUSE Leap 15.6 6.4.0-150600.10.49.1
  • kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.11.1
  • kernel-syms-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.11.1
  • kernel-source-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.20.11.1
  • kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.11.1

suse advisories SUSE-SU-2025:03023-1SUSE-SU-2025:03011-1SUSE-SU-2025:02997-1SUSE-SU-2025:02996-1SUSE-SU-2025:20586-1SUSE-SU-2025:20602-1

  • kernel Azure Linux 3.0 6.6.64.2-9

azure linux advisories AZL-49924

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Is CVE-2024-44963 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-44963 updated cvss 5.5

kernel: btrfs: do not BUG_ON() when freeing tree block after error

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2y ago

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.