CVE-2025-38220

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2025-38220
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.

5.5 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/be5f3061a6f904e3674257879e71881ceee5b673 Patch
https://git.kernel.org/stable/c/cf6a4c4ac7b6e3214f25df594c9689a62f1bb456 Patch
https://git.kernel.org/stable/c/d7af6eee8cd60f55aa8c5fe2b91f11ec0c9a0f27 Patch
https://git.kernel.org/stable/c/e26268ff1dcae5662c1b96c35f18cfa6ab73d9de Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
History

18 Nov 2025, 15:17

Type Values Removed Values Added
CWE CWE-476
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.5
First Time Linux
Linux linux Kernel
References () https://git.kernel.org/stable/c/be5f3061a6f904e3674257879e71881ceee5b673 - () https://git.kernel.org/stable/c/be5f3061a6f904e3674257879e71881ceee5b673 - Patch
References () https://git.kernel.org/stable/c/cf6a4c4ac7b6e3214f25df594c9689a62f1bb456 - () https://git.kernel.org/stable/c/cf6a4c4ac7b6e3214f25df594c9689a62f1bb456 - Patch
References () https://git.kernel.org/stable/c/d7af6eee8cd60f55aa8c5fe2b91f11ec0c9a0f27 - () https://git.kernel.org/stable/c/d7af6eee8cd60f55aa8c5fe2b91f11ec0c9a0f27 - Patch
References () https://git.kernel.org/stable/c/e26268ff1dcae5662c1b96c35f18cfa6ab73d9de - () https://git.kernel.org/stable/c/e26268ff1dcae5662c1b96c35f18cfa6ab73d9de - Patch

08 Jul 2025, 16:18

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ext4: solo folios sucios cuando se registran datos de archivos normales fstest generic/388 ocasionalmente reproduce un fallo que se parece a lo siguiente: ERROR: desreferencia de puntero NULL del kernel, dirección: 0000000000000000 ... Seguimiento de llamadas: 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 ... Esto ocurre al procesar un inodo de enlace simbólico de la lista de huérfanos. El código de puesta a cero parcial de bloques en la ruta de truncamiento llama a ext4_dirty_journalled_data() -&gt; folio_mark_dirty(). Este último llama a mapping-&gt;a_ops-&gt;dirty_folio(), pero los inodos de enlace simbólico no tienen asignado un vector a_ops en ext4, lo que explica el fallo. Para evitar este problema, actualice el asistente ext4_dirty_journalled_data() para que solo marque el folio como sucio en archivos normales (para los que se asigna a_ops). Esto también coincide con la lógica de registro en la ruta de creación de ext4_symlink(), donde se llama directamente a ext4_handle_dirty_metadata().

04 Jul 2025, 14:15

Type Values Removed Values Added
New CVE
Information

Published : 2025-07-04 14:15

Updated : 2025-11-18 15:17

NVD link : CVE-2025-38220

Mitre link : CVE-2025-38220

CVE.ORG link : CVE-2025-38220

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-476

NULL Pointer Dereference