CVE-2025-21722

In the Linux kernel, the following vulnerability has been resolved: nilfs2: do not force clear folio if buffer is referenced Patch series "nilfs2: protect busy buffer heads from being force-cleared". This series fixes the buffer head state inconsistency issues reported by syzbot that occurs when the filesystem is corrupted and falls back to read-only, and the associated buffer head use-after-free issue. This patch (of 2): Syzbot has reported that after nilfs2 detects filesystem corruption and falls back to read-only, inconsistencies in the buffer state may occur. One of the inconsistencies is that when nilfs2 calls mark_buffer_dirty() to set a data or metadata buffer as dirty, but it detects that the buffer is not in the uptodate state: WARNING: CPU: 0 PID: 6049 at fs/buffer.c:1177 mark_buffer_dirty+0x2e5/0x520 fs/buffer.c:1177 ... Call Trace: <TASK> nilfs_palloc_commit_alloc_entry+0x4b/0x160 fs/nilfs2/alloc.c:598 nilfs_ifile_create_inode+0x1dd/0x3a0 fs/nilfs2/ifile.c:73 nilfs_new_inode+0x254/0x830 fs/nilfs2/inode.c:344 nilfs_mkdir+0x10d/0x340 fs/nilfs2/namei.c:218 vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257 do_mkdirat+0x264/0x3a0 fs/namei.c:4280 __do_sys_mkdirat fs/namei.c:4295 [inline] __se_sys_mkdirat fs/namei.c:4293 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The other is when nilfs_btree_propagate(), which propagates the dirty state to the ancestor nodes of a b-tree that point to a dirty buffer, detects that the origin buffer is not dirty, even though it should be: WARNING: CPU: 0 PID: 5245 at fs/nilfs2/btree.c:2089 nilfs_btree_propagate+0xc79/0xdf0 fs/nilfs2/btree.c:2089 ... Call Trace: <TASK> nilfs_bmap_propagate+0x75/0x120 fs/nilfs2/bmap.c:345 nilfs_collect_file_data+0x4d/0xd0 fs/nilfs2/segment.c:587 nilfs_segctor_apply_buffers+0x184/0x340 fs/nilfs2/segment.c:1006 nilfs_segctor_scan_file+0x28c/0xa50 fs/nilfs2/segment.c:1045 nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1216 [inline] nilfs_segctor_collect fs/nilfs2/segment.c:1540 [inline] nilfs_segctor_do_construct+0x1c28/0x6b90 fs/nilfs2/segment.c:2115 nilfs_segctor_construct+0x181/0x6b0 fs/nilfs2/segment.c:2479 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2587 [inline] nilfs_segctor_thread+0x69e/0xe80 fs/nilfs2/segment.c:2701 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Both of these issues are caused by the callbacks that handle the page/folio write requests, forcibly clear various states, including the working state of the buffers they hold, at unexpected times when they detect read-only fallback. Fix these issues by checking if the buffer is referenced before clearing the page/folio state, and skipping the clear if it is.
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:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

History

24 Mar 2025, 18:27

Type Values Removed Values Added
First Time Linux linux Kernel
Linux
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
References () https://git.kernel.org/stable/c/1098bb8d52419d262a3358d099a1598a920b730f - () https://git.kernel.org/stable/c/1098bb8d52419d262a3358d099a1598a920b730f - Patch
References () https://git.kernel.org/stable/c/19296737024cd220a1d6590bf4c092bca8c99497 - () https://git.kernel.org/stable/c/19296737024cd220a1d6590bf4c092bca8c99497 - Patch
References () https://git.kernel.org/stable/c/4d042811c72f71be7c14726db2c72b67025a7cb5 - () https://git.kernel.org/stable/c/4d042811c72f71be7c14726db2c72b67025a7cb5 - Patch
References () https://git.kernel.org/stable/c/557ccf5e49f1fb848a29698585bcab2e50a597ef - () https://git.kernel.org/stable/c/557ccf5e49f1fb848a29698585bcab2e50a597ef - Patch
References () https://git.kernel.org/stable/c/7d0544bacc11d6aa26ecd7debf9353193c7a3328 - () https://git.kernel.org/stable/c/7d0544bacc11d6aa26ecd7debf9353193c7a3328 - Patch
References () https://git.kernel.org/stable/c/ca76bb226bf47ff04c782cacbd299f12ddee1ec1 - () https://git.kernel.org/stable/c/ca76bb226bf47ff04c782cacbd299f12ddee1ec1 - Patch
References () https://git.kernel.org/stable/c/f51ff43c4c5a6c8e72d0aca89e4d5e688938412f - () https://git.kernel.org/stable/c/f51ff43c4c5a6c8e72d0aca89e4d5e688938412f - Patch

13 Mar 2025, 13:15

Type Values Removed Values Added
References
  • () https://git.kernel.org/stable/c/4d042811c72f71be7c14726db2c72b67025a7cb5 -
  • () https://git.kernel.org/stable/c/7d0544bacc11d6aa26ecd7debf9353193c7a3328 -
  • () https://git.kernel.org/stable/c/f51ff43c4c5a6c8e72d0aca89e4d5e688938412f -
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: nilfs2: no fuerza la depuración del folio si se hace referencia al búfer Serie de parches "nilfs2: protege los cabezales de búfer ocupados de ser borrados a la fuerza". Esta serie corrige los problemas de inconsistencia del estado del cabezal de búfer informados por syzbot que ocurren cuando el sistema de archivos está dañado y vuelve a solo lectura, y el problema asociado de uso del cabezal de búfer después de la liberación. Este parche (de 2): Syzbot ha informado que después de que nilfs2 detecta la corrupción del sistema de archivos y vuelve a solo lectura, pueden ocurrir inconsistencias en el estado del búfer. Una de las inconsistencias es que cuando nilfs2 llama a mark_buffer_dirty() para establecer un búfer de datos o metadatos como sucio, pero detecta que el búfer no está en el estado actualizado: ADVERTENCIA: CPU: 0 PID: 6049 at fs/buffer.c:1177 mark_buffer_dirty+0x2e5/0x520 fs/buffer.c:1177 ... Call Trace: nilfs_palloc_commit_alloc_entry+0x4b/0x160 fs/nilfs2/alloc.c:598 nilfs_ifile_create_inode+0x1dd/0x3a0 fs/nilfs2/ifile.c:73 nilfs_new_inode+0x254/0x830 fs/nilfs2/inode.c:344 nilfs_mkdir+0x10d/0x340 fs/nilfs2/namei.c:218 vfs_mkdir+0x2f9/0x4f0 fs/namei.c:4257 do_mkdirat+0x264/0x3a0 fs/namei.c:4280 __do_sys_mkdirat fs/namei.c:4295 [inline] __se_sys_mkdirat fs/namei.c:4293 [inline] __x64_sys_mkdirat+0x87/0xa0 fs/namei.c:4293 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The other is when nilfs_btree_propagate(), which propagates the dirty state to the ancestor nodes of a b-tree that point to a dirty buffer, detects that the origin buffer is not dirty, even though it should be: WARNING: CPU: 0 PID: 5245 at fs/nilfs2/btree.c:2089 nilfs_btree_propagate+0xc79/0xdf0 fs/nilfs2/btree.c:2089 ... Call Trace: nilfs_bmap_propagate+0x75/0x120 fs/nilfs2/bmap.c:345 nilfs_collect_file_data+0x4d/0xd0 fs/nilfs2/segment.c:587 nilfs_segctor_apply_buffers+0x184/0x340 fs/nilfs2/segment.c:1006 nilfs_segctor_scan_file+0x28c/0xa50 fs/nilfs2/segment.c:1045 nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1216 [inline] nilfs_segctor_collect fs/nilfs2/segment.c:1540 [inline] nilfs_segctor_do_construct+0x1c28/0x6b90 fs/nilfs2/segment.c:2115 nilfs_segctor_construct+0x181/0x6b0 fs/nilfs2/segment.c:2479 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2587 [inline] nilfs_segctor_thread+0x69e/0xe80 fs/nilfs2/segment.c:2701 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Ambos problemas son causados por las devoluciones de llamadas que manejan las solicitudes de escritura de página/folio, borran a la fuerza varios estados, incluido el estado de trabajo de los búferes que contienen, en momentos inesperados cuando detectan una reserva de solo lectura. Solucione estos problemas verificando si se hace referencia al búfer antes de borrar el estado de la página/folio y omitiendo la limpieza si es así.

27 Feb 2025, 19:15

Type Values Removed Values Added
CWE CWE-416
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 7.8

27 Feb 2025, 02:15

Type Values Removed Values Added
New CVE

Information

Published : 2025-02-27 02:15

Updated : 2025-03-24 18:27


NVD link : CVE-2025-21722

Mitre link : CVE-2025-21722

CVE.ORG link : CVE-2025-21722


JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-416

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