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().
https://git.kernel.org/stable/c/eff7cdf890b02596b8d73e910bdbdd489175dbdb
https://git.kernel.org/stable/c/eb85dace897c5986bc2f36b3c783c6abb8a4292e
https://git.kernel.org/stable/c/c516db6ab9eabbedbc430b4f93b0d8728e9b427f
https://git.kernel.org/stable/c/bc9cee50a4a4ca23bdc49f75ea8242d8a2193b3b
https://git.kernel.org/stable/c/a8799662fed1f8747edae87a1937549288baca6a
https://git.kernel.org/stable/c/911d38be151921a5d152bb55e81fd752384c6830
https://git.kernel.org/stable/c/6e5c8e8e024e147b834f56f2115aad241433679b
https://git.kernel.org/stable/c/1c3844c5f4eac043954ebf6403fa9fd1f0e9c1c0
https://git.kernel.org/stable/c/06afce714d87c7cd1dcfccbcd800c5c5d2cf1cfd