====================================================== WARNING: possible circular locking dependency detected 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Not tainted ------------------------------------------------------ syz-executor.3/3071 is trying to acquire lock: ffff0000c96eca70 (&dat_lock_key){.+.+}-{3:3}, at: nilfs_count_free_blocks+0x2c/0x6c fs/nilfs2/the_nilfs.c:693 but task is already holding lock: ffff0001178b6090 (&nilfs->ns_sem){++++}-{3:3}, at: nilfs_sync_fs+0x74/0x354 fs/nilfs2/super.c:494 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&nilfs->ns_sem){++++}-{3:3}: down_write+0x5c/0xcc kernel/locking/rwsem.c:1552 nilfs_set_error fs/nilfs2/super.c:92 [inline] __nilfs_error+0xb4/0x284 fs/nilfs2/super.c:137 nilfs_bmap_convert_error fs/nilfs2/bmap.c:35 [inline] nilfs_bmap_lookup_contig+0x98/0xc0 fs/nilfs2/bmap.c:95 nilfs_get_block+0x7c/0x364 fs/nilfs2/inode.c:85 block_truncate_page+0x1b4/0xab4 fs/buffer.c:2583 nilfs_truncate+0xb8/0x178 fs/nilfs2/inode.c:857 nilfs_setattr+0xf8/0x164 fs/nilfs2/inode.c:955 notify_change+0x758/0x7f0 fs/attr.c:420 do_truncate+0x108/0x150 fs/open.c:65 vfs_truncate+0x1dc/0x24c fs/open.c:111 do_sys_truncate+0x94/0x140 fs/open.c:134 __do_sys_truncate fs/open.c:146 [inline] __se_sys_truncate fs/open.c:144 [inline] __arm64_sys_truncate+0x20/0x30 fs/open.c:144 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline] invoke_syscall arch/arm64/kernel/syscall.c:52 [inline] el0_svc_common+0x138/0x220 arch/arm64/kernel/syscall.c:142 do_el0_svc+0x48/0x164 arch/arm64/kernel/syscall.c:206 el0_svc+0x58/0x150 arch/arm64/kernel/entry-common.c:636 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 -> #0 (&dat_lock_key){.+.+}-{3:3}: check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 down_read+0x5c/0x78 kernel/locking/rwsem.c:1499 nilfs_count_free_blocks+0x2c/0x6c fs/nilfs2/the_nilfs.c:693 nilfs_set_log_cursor fs/nilfs2/super.c:236 [inline] nilfs_sync_fs+0x1a8/0x354 fs/nilfs2/super.c:498 sync_filesystem+0x68/0x134 fs/sync.c:56 generic_shutdown_super+0x38/0x190 fs/super.c:474 kill_block_super+0x30/0x78 fs/super.c:1427 deactivate_locked_super+0x70/0xe8 fs/super.c:332 deactivate_super+0xd0/0xd4 fs/super.c:363 cleanup_mnt+0x1f8/0x234 fs/namespace.c:1186 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193 task_work_run+0xc4/0x14c kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x174/0x1f0 arch/arm64/kernel/signal.c:1127 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&nilfs->ns_sem); lock(&dat_lock_key); lock(&nilfs->ns_sem); lock(&dat_lock_key); *** DEADLOCK *** 2 locks held by syz-executor.3/3071: #0: ffff000104d290e0 (&type->s_umount_key#61){+.+.}-{3:3}, at: deactivate_super+0xc8/0xd4 fs/super.c:362 #1: ffff0001178b6090 (&nilfs->ns_sem){++++}-{3:3}, at: nilfs_sync_fs+0x74/0x354 fs/nilfs2/super.c:494 stack backtrace: CPU: 1 PID: 3071 Comm: syz-executor.3 Not tainted 6.0.0-rc7-syzkaller-18095-gbbed346d5a96 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/30/2022 Call trace: dump_backtrace+0x1c4/0x1f0 arch/arm64/kernel/stacktrace.c:156 show_stack+0x2c/0x54 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x104/0x16c lib/dump_stack.c:106 dump_stack+0x1c/0x58 lib/dump_stack.c:113 print_circular_bug+0x2c4/0x2c8 kernel/locking/lockdep.c:2053 check_noncircular+0x14c/0x154 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3095 [inline] check_prevs_add kernel/locking/lockdep.c:3214 [inline] validate_chain kernel/locking/lockdep.c:3829 [inline] __lock_acquire+0x1530/0x30a4 kernel/locking/lockdep.c:5053 lock_acquire+0x100/0x1f8 kernel/locking/lockdep.c:5666 down_read+0x5c/0x78 kernel/locking/rwsem.c:1499 nilfs_count_free_blocks+0x2c/0x6c fs/nilfs2/the_nilfs.c:693 nilfs_set_log_cursor fs/nilfs2/super.c:236 [inline] nilfs_sync_fs+0x1a8/0x354 fs/nilfs2/super.c:498 sync_filesystem+0x68/0x134 fs/sync.c:56 generic_shutdown_super+0x38/0x190 fs/super.c:474 kill_block_super+0x30/0x78 fs/super.c:1427 deactivate_locked_super+0x70/0xe8 fs/super.c:332 deactivate_super+0xd0/0xd4 fs/super.c:363 cleanup_mnt+0x1f8/0x234 fs/namespace.c:1186 __cleanup_mnt+0x20/0x30 fs/namespace.c:1193 task_work_run+0xc4/0x14c kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] do_notify_resume+0x174/0x1f0 arch/arm64/kernel/signal.c:1127 prepare_exit_to_user_mode arch/arm64/kernel/entry-common.c:137 [inline] exit_to_user_mode arch/arm64/kernel/entry-common.c:142 [inline] el0_svc+0x9c/0x150 arch/arm64/kernel/entry-common.c:637 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:654 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581