In the Linux kernel, the following vulnerability has been resolved: nilfs2: fix use-after-free of timer for log writer thread Patch series "nilfs2: fix log writer related issues". This bug fix series covers three nilfs2 log writer-related issues, including a timer use-after-free issue and potential deadlock issue on unmount, and a potential freeze issue in event synchronization found during their analysis. Details are described in each commit log. This patch (of 3): A use-after-free issue has been reported regarding the timer sctimer on the nilfsscinfo structure. The problem is that even though it is used to wake up a sleeping log writer thread, sctimer is not shut down until the nilfsscinfo structure is about to be freed, and is used regardless of the thread's lifetime. Fix this issue by limiting the use of sc_timer only while the log writer thread is alive.