On 2021/11/4 16:22, Dongliang Mu wrote:
if2fs_fill_super -> f2fs_build_segment_manager -> create_discard_cmd_control -> f2fs_start_discard_threadIt invokes kthread_run to create a thread and run issue_discard_thread. However, if f2fs_build_node_manager fails, the control flow goes to free_nm and calls f2fs_destroy_node_manager. This function will free sbi->nm_info. However, if issue_discard_thread accesses sbi->nm_info after the deallocation, but before the f2fs_stop_discard_thread, it will cause UAF(Use-after-free). -> f2fs_destroy_segment_manager -> destroy_discard_cmd_control -> f2fs_stop_discard_thread Fix this by stopping discard thread before f2fs_destroy_node_manager. Note that, the commit d6d2b491a82e1 introduces the call of f2fs_available_free_memory into issue_discard_thread. Fixes: d6d2b491a82e ("f2fs: allow to change discard policy based on cached discard cmds") Signed-off-by: Dongliang Mu <mudonglianga...@gmail.com>
Reviewed-by: Chao Yu <c...@kernel.org> Thanks, _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
