CVE-2025-38220
Vulnerability Summary
Timeline
Description
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.
CVSS Metrics
- v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS Trends
Current EPSS score: 0.14%• Percentile: 4%
Techniques & Countermeasures
- CWE-476•NULL Pointer Dereference
The product dereferences a pointer that it expects to be valid but is NULL.
Affected Systems
- debian•linux
< 6.12.35-1 | < 6.12.35-1
- ubuntu•linux
< 6.8.0-100.100
- ubuntu•linux-allwinner-5.19
all
- ubuntu•linux-aws
< 6.8.0-1046.49
- ubuntu•linux-aws-5.0
all
- ubuntu•linux-aws-5.11
all
- ubuntu•linux-aws-5.13
all
- ubuntu•linux-aws-5.19
all
- ubuntu•linux-aws-5.3
all
- ubuntu•linux-aws-5.8
all
- ubuntu•linux-aws-6.14
< 6.14.0-1015.15~24.04.1
- ubuntu•linux-aws-6.2
all
- ubuntu•linux-aws-6.5
all
- ubuntu•linux-aws-6.8
< 6.8.0-1046.49~22.04.1
- ubuntu•linux-aws-fips
< 6.8.0-1046.49+fips1
- ubuntu•linux-azure
all | < 6.8.0-1046.52
- ubuntu•linux-azure-5.11
all
- ubuntu•linux-azure-5.13
all
- ubuntu•linux-azure-5.19
all
- ubuntu•linux-azure-5.3
all
- ubuntu•linux-azure-5.8
all
- ubuntu•linux-azure-6.11
all
- ubuntu•linux-azure-6.14
< 6.14.0-1014.14~24.04.1
- ubuntu•linux-azure-6.2
all
- ubuntu•linux-azure-6.5
all
- ubuntu•linux-azure-6.8
< 6.8.0-1051.57~22.04.1
- ubuntu•linux-azure-edge
all
- ubuntu•linux-azure-fde
all | all | all
- ubuntu•linux-azure-fde-5.19
all
- ubuntu•linux-azure-fde-6.2
all
- ubuntu•linux-azure-fde-6.8
all
- ubuntu•linux-azure-fips
< 6.8.0-1046.52+fips1
- ubuntu•linux-azure-nvidia
all
- ubuntu•linux-azure-nvidia-6.14
< 6.14.0-1007.7
- ubuntu•linux-bluefield
all | < 6.8.0-1016.20
- ubuntu•linux-fips
< 6.8.0-100.100+fips1
- ubuntu•linux-gcp
all | < 6.8.0-1047.50
- ubuntu•linux-gcp-5.11
all
- ubuntu•linux-gcp-5.13
all
- ubuntu•linux-gcp-5.19
all
- ubuntu•linux-gcp-5.3
all
- ubuntu•linux-gcp-5.8
all
- ubuntu•linux-gcp-6.11
all
- ubuntu•linux-gcp-6.14
< 6.14.0-1018.19~24.04.1
- ubuntu•linux-gcp-6.2
all
- ubuntu•linux-gcp-6.5
all
- ubuntu•linux-gcp-6.8
< 6.8.0-1047.50~22.04.2
- ubuntu•linux-gcp-fips
< 6.8.0-1047.50+fips1
- ubuntu•linux-gke
all | < 6.8.0-1043.48
- ubuntu•linux-gke-4.15
all
Showing first 50 affected entries in server-rendered view.
References (30)
- https://git.kernel.org/stable/c/cf6a4c4ac7b6e3214f25df594c9689a62f1bb456
- https://git.kernel.org/stable/c/be5f3061a6f904e3674257879e71881ceee5b673
- https://git.kernel.org/stable/c/d7af6eee8cd60f55aa8c5fe2b91f11ec0c9a0f27
- https://git.kernel.org/stable/c/e26268ff1dcae5662c1b96c35f18cfa6ab73d9de
- https://ubuntu.com/security/CVE-2025-38220
- https://www.cve.org/CVERecord?id=CVE-2025-38220
- https://git.kernel.org/linus/e26268ff1dcae5662c1b96c35f18cfa6ab73d9de
- https://ubuntu.com/security/notices/USN-7833-1
- https://ubuntu.com/security/notices/USN-7834-1
- https://ubuntu.com/security/notices/USN-7833-2
- https://ubuntu.com/security/notices/USN-7833-3
- https://ubuntu.com/security/notices/USN-7833-4
- https://ubuntu.com/security/notices/USN-7856-1
- https://ubuntu.com/security/notices/USN-8028-1
- https://ubuntu.com/security/notices/USN-8028-2
- https://ubuntu.com/security/notices/USN-8031-1
- https://ubuntu.com/security/notices/USN-8028-3
- https://ubuntu.com/security/notices/USN-8028-4
- https://ubuntu.com/security/notices/USN-8028-5
- https://ubuntu.com/security/notices/USN-8031-2
- https://ubuntu.com/security/notices/USN-8028-6
- https://ubuntu.com/security/notices/USN-8031-3
- https://ubuntu.com/security/notices/USN-8052-1
- https://ubuntu.com/security/notices/USN-8028-7
- https://ubuntu.com/security/notices/USN-8028-8
- https://ubuntu.com/security/notices/USN-8052-2
- https://ubuntu.com/security/notices/USN-8074-1
- https://ubuntu.com/security/notices/USN-8074-2
- https://ubuntu.com/security/notices/USN-8126-1
- https://security-tracker.debian.org/tracker/CVE-2025-38220