Bug 2420262 (CVE-2023-53804)

Summary: CVE-2023-53804 kernel: nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2025-12-09 01:04:09 UTC 
In the Linux kernel, the following vulnerability has been resolved:

nilfs2: fix use-after-free bug of nilfs_root in nilfs_evict_inode()

During unmount process of nilfs2, nothing holds nilfs_root structure after
nilfs2 detaches its writer in nilfs_detach_log_writer().  However, since
nilfs_evict_inode() uses nilfs_root for some cleanup operations, it may
cause use-after-free read if inodes are left in "garbage_list" and
released by nilfs_dispose_list() at the end of nilfs_detach_log_writer().

Fix this issue by modifying nilfs_evict_inode() to only clear inode
without additional metadata changes that use nilfs_root if the file system
is degraded to read-only or the writer is detached.
Comment 1 Alexander B 2025-12-10 06:26:48 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025120943-CVE-2023-53804-3c10@gregkh/T