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Fencer Vulns
medium 5.5

CVE-2025-38220 json

ext4: only dirty folios when data journaling regular files

published 2025-07-04 16 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-20036

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 6%
public exploits
0
none known

Summary

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

ext4: only dirty folios when data journaling regular files

fstest generic/388 occasionally reproduces a crash that looks as follows:

BUG: kernel NULL pointer dereference, address: 0000000000000000 ... Call Trace: <TASK> ext4_block_zero_page_range+0x30c/0x380 [ext4] ext4_truncate+0x436/0x440 [ext4] ext4_process_orphan+0x5d/0x110 [ext4] ext4_orphan_cleanup+0x124/0x4f0 [ext4] ext4_fill_super+0x262d/0x3110 [ext4] get_tree_bdev_flags+0x132/0x1d0 vfs_get_tree+0x26/0xd0 vfs_cmd_create+0x59/0xe0 __do_sys_fsconfig+0x4ed/0x6b0 do_syscall_64+0x82/0x170 ...

This occurs when processing a symlink inode from the orphan list. The partial block zeroing code in the truncate path calls ext4_dirty_journalled_data() -> folio_mark_dirty(). The latter calls mapping->a_ops->dirty_folio(), but symlink inodes are not assigned an a_ops vector in ext4, hence the crash.

To avoid this problem, update the ext4_dirty_journalled_data() helper to only mark the folio dirty on regular files (for which a_ops is assigned). This also matches the journaling logic in the ext4_symlink() creation path, where ext4_handle_dirty_metadata() is called directly.

Patch / fix

  • Linux Linux 6.6.95, 6.12.35, 6.15.4, 6.16
  • linux Debian 14, Debian 13 6.12.35-1

debian advisories DEBIAN-CVE-2025-38220

  • linux Ubuntu 24.04 LTS 6.8.0-100.100
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1046.49
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1047.50
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1043.48
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1044.44
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1046.52
  • linux-gkeop Ubuntu 24.04 LTS 6.8.0-1030.33
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1047.51

ubuntu advisories UBUNTU-CVE-2025-38220

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 RHEL 10.1 6.12.0-124.8.1.el10_1
  • rv RHEL 10.1 6.12.0-124.8.1.el10_1
  • perf RHEL 10.1 6.12.0-124.8.1.el10_1
  • rtla RHEL 10.1 6.12.0-124.8.1.el10_1
  • libperf RHEL 10.1 6.12.0-124.8.1.el10_1
  • kernel-rt RHEL 10.1 6.12.0-124.8.1.el10_1
  • kernel-64k RHEL 10.1 6.12.0-124.8.1.el10_1
  • kernel-core RHEL 10.1 6.12.0-124.8.1.el10_1

red hat advisories RHSA-2025:20095RHSA-2025:15005

  • kernel-rt Linux Micro 6.2 6.12.0-160000.6.1
  • kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.6.1
  • kernel-source SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.6.1
  • kernel-default SLES 16.0, SLE High Availability Extension 16.0, Linux Micro 6.2 +1 more 6.12.0-160000.6.1
  • kernel-default-base SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.6.1.160000.2.4
  • kernel-syms SLES 16.0, Linux Micro Extras 6.2, SLES for SAP applications 16.0 6.12.0-160000.6.1
  • kernel-obs-qa SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.6.1
  • kernel-kvmsmall SLES for SAP applications 16.0, SLES 16.0 6.12.0-160000.6.1

suse advisories SUSE-SU-2025:21074-1SUSE-SU-2025:21139-1SUSE-SU-2026:20560-1SUSE-SU-2025:21179-1SUSE-SU-2025:03023-1SUSE-SU-2025:03011-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.6.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.6.1
  • kernel-kvmsmall openSUSE Leap 16.0 6.12.0-160000.6.1

opensuse advisories openSUSE-SU-2025:20081-1

  • kernel-abi-stablelists AlmaLinux 10 6.12.0-55.30.1.el10_0

almalinux advisories ALSA-2025:15005

  • kernel Rocky Linux 10 6.12.0-55.30.1.el10_0

rocky linux advisories RLSA-2025:15005

  • kernel Azure Linux 3.0 6.6.96.1-1

azure linux advisories AZL-64767

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

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-2025-38220 updated cvss 7.0

kernel: ext4: only dirty folios when data journaling regular files

  • Red Hat Enterprise Linux AppStream (v. 10) rv 6.12.0-124.8.1.el10_1, rv 6.12.0-55.30.1.el10_0, perf 6.12.0-124.8.1.el10_1, perf 6.12.0-55.30.1.el10_0, rtla 6.12.0-124.8.1.el10_1, rtla 6.12.0-55.30.1.el10_0, +20 more Red Hat Enterprise Linux BaseOS (v. 10) kernel 6.12.0-124.8.1.el10_1, kernel 6.12.0-55.30.1.el10_0, kernel-64k 6.12.0-124.8.1.el10_1, kernel-64k 6.12.0-55.30.1.el10_0, kernel-core 6.12.0-124.8.1.el10_1, kernel-core 6.12.0-55.30.1.el10_0, +61 more Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) libperf 6.12.0-124.8.1.el10_1, libperf 6.12.0-55.30.1.el10_0, kernel-debuginfo-common-s390x 6.12.0-124.8.1.el10_1, kernel-debuginfo-common-s390x 6.12.0-55.30.1.el10_0, kernel-debuginfo-common-x86_64 6.12.0-124.8.1.el10_1, kernel-debuginfo-common-x86_64 6.12.0-55.30.1.el10_0, +4 more Red Hat Enterprise Linux Real Time (v. 10) kernel-rt 6.12.0-124.8.1.el10_1, kernel-rt 6.12.0-55.30.1.el10_0, kernel-rt-64k 6.12.0-124.8.1.el10_1, kernel-rt-64k 6.12.0-55.30.1.el10_0, kernel-rt-core 6.12.0-124.8.1.el10_1, kernel-rt-core 6.12.0-55.30.1.el10_0, +34 more Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt 6.12.0-124.8.1.el10_1, kernel-rt 6.12.0-55.30.1.el10_0, kernel-rt-kvm 6.12.0-55.30.1.el10_0, kernel-rt-core 6.12.0-124.8.1.el10_1, kernel-rt-core 6.12.0-55.30.1.el10_0, kernel-rt-modules 6.12.0-124.8.1.el10_1, +16 more
    fixed: vendor fix RHSA-2025:15005
  • 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 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

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% 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.