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🛡️ CVE-2025-38220 — kernel

🟡 CVSS 5.5 — Medium ✅ No Known Exploit NVD
5.5
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

ext4: only dirty folios when data journaling regular files

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.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.

Affected software

CVE-2025-38220 is recorded against 2 packages.

  • kernel (from 6.13.0 up to 6.15.4)
  • linux-kernel (from 6.13 up to 6.15.4)

Timeline and source

Published on 4 July 2025 and last revised on 12 August 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
github.com (Advisory)
nvd.nist.gov (Advisory)
git.kernel.org (Package)

CVE-2025-38220 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity Medium
CVSS Score 5.5
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE N/A
Public Exploit ✅ No
Source NVD
Published 2025-07-04
Updated 2026-08-20
Modified 2026-08-12

Affected Packages

Software From version Fixed in
kernel 6.13.0 6.15.4
linux-kernel 6.13 6.15.4

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