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Fencer Vulns
medium 5.5

CVE-2024-26696 json

nilfs2: fix hang in nilfs_lookup_dirty_data_buffers()

published 2024-04-03 2 y ago modified 2026-06-17 4 mo ago also EUVD-2024-23958

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 8%
public exploits
0
none known

Summary

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

nilfs2: fix hang in nilfs_lookup_dirty_data_buffers()

Syzbot reported a hang issue in migrate_pages_batch() called by mbind() and nilfs_lookup_dirty_data_buffers() called in the log writer of nilfs2.

While migrate_pages_batch() locks a folio and waits for the writeback to complete, the log writer thread that should bring the writeback to completion picks up the folio being written back in nilfs_lookup_dirty_data_buffers() that it calls for subsequent log creation and was trying to lock the folio. Thus causing a deadlock.

In the first place, it is unexpected that folios/pages in the middle of writeback will be updated and become dirty. Nilfs2 adds a checksum to verify the validity of the log being written and uses it for recovery at mount, so data changes during writeback are suppressed. Since this is broken, an unclean shutdown could potentially cause recovery to fail.

Investigation revealed that the root cause is that the wait for writeback completion in nilfs_page_mkwrite() is conditional, and if the backing device does not require stable writes, data may be modified without waiting.

Fix these issues by making nilfs_page_mkwrite() wait for writeback to finish regardless of the stable write requirement of the backing device.

Patch / fix

  • Linux Linux 4.19.307, 5.4.269, 5.10.210, 5.15.149, 6.1.79, 6.6.18, 6.7.6, 6.8
  • linux Debian 12 6.1.82-1
  • linux Debian 14, Debian 13 6.7.7-1

debian advisories DEBIAN-CVE-2024-26696

  • linux Ubuntu 20.04 LTS 5.4.0-181.201
  • linux Ubuntu 22.04 LTS 5.15.0-106.116
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1124.134
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1061.67
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1128.137
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1059.67
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1058.63
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1071.76

ubuntu advisories UBUNTU-CVE-2024-26696

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-azure SLE Module for Public Cloud 15 SP6, openSUSE Leap 15.6 6.4.0-150600.8.5.4
  • kernel-syms-azure SLE Module for Public Cloud 15 SP6, openSUSE Leap 15.6 6.4.0-150600.8.5.1
  • kernel-source-azure SLE Module for Public Cloud 15 SP6, openSUSE Leap 15.6 6.4.0-150600.8.5.4
  • kernel-rt SLE Micro 5.5, Real Time Module 15 SP5, openSUSE Leap 15.5 5.14.21-150500.13.52.1
  • kernel-syms-rt Real Time Module 15 SP5, openSUSE Leap 15.5 5.14.21-150500.13.52.1
  • kernel-rt_debug Real Time Module 15 SP5, openSUSE Leap 15.5 5.14.21-150500.13.52.1
  • kernel-source-rt SLE Micro 5.5, Real Time Module 15 SP5, openSUSE Leap 15.5 5.14.21-150500.13.52.1
  • dtb-aarch64 openSUSE Leap 15.5 5.14.21-150500.55.62.1

suse advisories SUSE-SU-2024:2135-1SUSE-SU-2024:1663-1SUSE-SU-2024:1659-1SUSE-SU-2024:1490-1

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-2024-26696 updated cvss 5.5

kernel: nilfs2: fix hang in nilfs_lookup_dirty_data_buffers()

  • 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 ICSA-25-226-15 updated

Siemens SINEC OS

  • Siemens RUGGEDCOM RST2428P (6GK6242-6PA00) Siemens SCALANCE XC-300/XR-300/XC-400/XR-500WG/XR-500 family Siemens SCALANCE XCM-/XRM-/XCH-/XRH-300 family
    not affected

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

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

Weakness
Technology feeds

References

Sources

Fencer Vulns 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.