In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix use-after-free of nilfs_root in dirtying inodes via iput
During unmount process of nilfs2, nothing holds nilfs_root structure after
nilfs2 detaches its writer in nilfs_detach_log_writer(). Previously,
nilfs_evict_inode() could cause use-after-free read for nilfs_root if
inodes are left in "garbage_list" and released by nilfs_dispose_list at
the end of nilfs_detach_log_writer(), and this bug was fixed by commit
9b5a04ac3ad9 ("nilfs2: fix use-after-free bug of nilfs_root in
nilfs_evict_inode()").
However, it turned out that there is another possibility of UAF in the
call path where mark_inode_dirty_sync() is called from iput():
nilfs_detach_log_writer()
nilfs_dispose_list()
iput()
mark_inode_dirty_sync()
__mark_inode_dirty()
nilfs_dirty_inode()
__nilfs_mark_inode_dirty()
nilfs_load_inode_block() --> causes UAF of nilfs_root struct
This can happen after commit 0ae45f63d4ef ("vfs: add support for a
lazytime mount option"), which changed iput() to call
mark_inode_dirty_sync() on its final reference if i_state has I_DIRTY_TIME
flag and i_nlink is non-zero.
This issue appears after commit 28a65b49eb53 ("nilfs2: do not write dirty
data after degenerating to read-only") when using the syzbot reproducer,
but the issue has potentially existed before.
Fix this issue by adding a "purging flag" to the nilfs structure, setting
that flag while disposing the "garbage_list" and checking it in
__nilfs_mark_inode_dirty().
Unlike commit 9b5a04ac3ad9 ("nilfs2: fix use-after-free bug of nilfs_root
in nilfs_evict_inode()"), this patch does not rely on ns_writer to
determine whether to skip operations, so as not to break recovery on
mount. The nilfs_salvage_orphan_logs routine dirties the buffer of
salvaged data before attaching the log writer, so changing
__nilfs_mark_inode_dirty() to skip the operation when ns_writer is NULL
will cause recovery write to fail. The purpose of using the cleanup-only
flag is to allow for narrowing of such conditions.
References
Configurations
Configuration 1 (hide)
|
History
01 Dec 2025, 21:47
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:o:linux:linux_kernel:6.5:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.5:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.5:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.5:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.5:rc1:*:*:*:*:*:* |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.8 |
| First Time |
Linux linux Kernel
Linux |
|
| References | () https://git.kernel.org/stable/c/11afd67f1b3c28eb216e50a3ca8dbcb69bb71793 - Patch | |
| References | () https://git.kernel.org/stable/c/3645510cf926e6af2f4d44899370d7e5331c93bd - Patch | |
| References | () https://git.kernel.org/stable/c/37207240872456fbab44a110bde6640445233963 - Patch | |
| References | () https://git.kernel.org/stable/c/5828d5f5dc877dcfdd7b23102e978e2ecfd86d82 - Patch | |
| References | () https://git.kernel.org/stable/c/7532ff6edbf5242376b24a95a2fefb59bb653e5a - Patch | |
| References | () https://git.kernel.org/stable/c/a3c3b4cbf9b8554120fb230e6516e980c6277487 - Patch | |
| References | () https://git.kernel.org/stable/c/d2c539c216cce74837a9cf5804eb205939b82227 - Patch | |
| References | () https://git.kernel.org/stable/c/f8654743a0e6909dc634cbfad6db6816f10f3399 - Patch | |
| CWE | CWE-416 |
Information
Published : 2025-09-16 17:15
Updated : 2025-12-01 21:47
NVD link : CVE-2023-53311
Mitre link : CVE-2023-53311
CVE.ORG link : CVE-2023-53311
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-416
Use After Free