Description

In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix potential hang in nilfs_detach_log_writer() Syzbot has reported a potential hang in nilfs_detach_log_writer() called during nilfs2 unmount. Analysis revealed that this is because nilfs_segctor_sync(), which synchronizes with the log writer thread, can be called after nilfs_segctor_destroy() terminates that thread, as shown in the call trace below: nilfs_detach_log_writer nilfs_segctor_destroy nilfs_segctor_kill_thread --> Shut down log writer thread flush_work nilfs_iput_work_func nilfs_dispose_list iput nilfs_evict_inode nilfs_transaction_commit nilfs_construct_segment (if inode needs sync) nilfs_segctor_sync --> Attempt to synchronize with log writer thread *** DEADLOCK *** Fix this issue by changing nilfs_segctor_sync() so that the log writer thread returns normally without synchronizing after it terminates, and by forcing tasks that are already waiting to complete once after the thread terminates. The skipped inode metadata flushout will then be processed together in the subsequent cleanup work in nilfs_segctor_destroy().

Severity MEDIUM

CVSS Score 5.3

CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CWE CWE-667

Public Exploit ✅ No

Source NVD

Published 2024-06-19

Updated 2026-06-02

Modified 2025-11-04

Fix URL https://git.kernel.org/stable/c/06afce714d87c7cd1dcfccbcd800c5c5d2cf1cfd

Software	From version	Fixed in
linux-kernel	6.9	6.9.3