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.
References
Configurations
Configuration 1 (hide)
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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 - Patch | |
References | () https://git.kernel.org/stable/c/19296737024cd220a1d6590bf4c092bca8c99497 - Patch | |
References | () https://git.kernel.org/stable/c/4d042811c72f71be7c14726db2c72b67025a7cb5 - Patch | |
References | () https://git.kernel.org/stable/c/557ccf5e49f1fb848a29698585bcab2e50a597ef - Patch | |
References | () https://git.kernel.org/stable/c/7d0544bacc11d6aa26ecd7debf9353193c7a3328 - Patch | |
References | () https://git.kernel.org/stable/c/ca76bb226bf47ff04c782cacbd299f12ddee1ec1 - Patch | |
References | () https://git.kernel.org/stable/c/f51ff43c4c5a6c8e72d0aca89e4d5e688938412f - Patch |
13 Mar 2025, 13:15
Type | Values Removed | Values Added |
---|---|---|
References |
|
|
Summary |
|
27 Feb 2025, 19:15
Type | Values Removed | Values Added |
---|---|---|
CWE | CWE-416 | |
CVSS |
v2 : v3 : |
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
Use After Free