INFO: task syz-executor398:5001 blocked for more than 143 seconds. Not tainted 6.4.0-rc2-next-20230515-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor398 state:D stack:24808 pid:5001 ppid:4998 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x1d15/0x5790 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 wb_wait_for_completion+0x182/0x240 fs/fs-writeback.c:192 sync_inodes_sb+0x1aa/0xa60 fs/fs-writeback.c:2736 sync_filesystem.part.0+0xe6/0x1d0 fs/sync.c:64 sync_filesystem+0x8f/0xc0 fs/sync.c:43 generic_shutdown_super+0x74/0x480 fs/super.c:473 kill_block_super+0xa1/0x100 fs/super.c:1407 deactivate_locked_super+0x98/0x160 fs/super.c:331 deactivate_super+0xb1/0xd0 fs/super.c:362 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1177 task_work_run+0x16f/0x270 kernel/task_work.c:179 ptrace_notify+0x118/0x140 kernel/signal.c:2369 ptrace_report_syscall include/linux/ptrace.h:411 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:473 [inline] syscall_exit_work kernel/entry/common.c:252 [inline] syscall_exit_to_user_mode_prepare+0x129/0x220 kernel/entry/common.c:279 __syscall_exit_to_user_mode_work kernel/entry/common.c:284 [inline] syscall_exit_to_user_mode+0xd/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fe659309c97 RSP: 002b:00007ffeab64cbb8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fe659309c97 RDX: 00007ffeab64cc79 RSI: 000000000000000a RDI: 00007ffeab64cc70 RBP: 00007ffeab64cc70 R08: 00000000ffffffff R09: 00007ffeab64ca50 R10: 00005555563d4653 R11: 0000000000000206 R12: 00007ffeab64dcd0 R13: 00005555563d45f0 R14: 00007ffeab64cbe0 R15: 0000000000000001 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c798530 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:522 1 lock held by rcu_tasks_trace/14: #0: ffffffff8c798230 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:522 1 lock held by khungtaskd/28: #0: ffffffff8c799140 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x390 kernel/locking/lockdep.c:6559 2 locks held by kworker/u4:3/51: 2 locks held by getty/4756: #0: ffff88802c662098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015902f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2176 2 locks held by syz-executor398/5001: #0: ffff88807a3000e0 (&type->s_umount_key#42){+.+.}-{3:3}, at: deactivate_super+0xa9/0xd0 fs/super.c:361 #1: ffff88801eadc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff88801eadc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x190/0xa60 fs/fs-writeback.c:2734 1 lock held by segctord/5004: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc2-next-20230515-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xe16/0x1090 kernel/hung_task.c:379 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5004 Comm: segctord Not tainted 6.4.0-rc2-next-20230515-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x8/0x20 kernel/kcov.c:304 Code: 00 00 f3 0f 1e fa 48 8b 0c 24 0f b7 d6 0f b7 f7 bf 03 00 00 00 e9 b8 fe ff ff 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 48 8b 0c 24 <89> f2 89 fe bf 05 00 00 00 e9 9a fe ff ff 66 2e 0f 1f 84 00 00 00 RSP: 0018:ffffc900038ff4a8 EFLAGS: 00000246 RAX: 0000000000000007 RBX: ffffea0001e9f274 RCX: ffffffff832d7cb1 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000 RBP: ffff8880739cf2b8 R08: 0000000000000000 R09: fffff940003d3e4e R10: ffffea0001e9f277 R11: 0000000000094001 R12: ffffea0001e9f240 R13: 0000000000000003 R14: 0000000000000002 R15: 00000000ffffffef FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000558e5e8f9600 CR3: 000000000c571000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: put_page_testzero include/linux/mm.h:1009 [inline] folio_put_testzero include/linux/mm.h:1015 [inline] folio_put include/linux/mm.h:1442 [inline] put_page include/linux/mm.h:1512 [inline] nilfs_mdt_submit_block+0x4d1/0x9d0 fs/nilfs2/mdt.c:162 nilfs_mdt_read_block+0x92/0x3c0 fs/nilfs2/mdt.c:176 nilfs_mdt_get_block+0xe5/0xcf0 fs/nilfs2/mdt.c:251 nilfs_palloc_get_block+0xc4/0x2b0 fs/nilfs2/alloc.c:216 nilfs_palloc_get_entry_block+0x16b/0x1d0 fs/nilfs2/alloc.c:318 nilfs_dat_prepare_entry fs/nilfs2/dat.c:45 [inline] nilfs_dat_mark_dirty+0x7c/0x140 fs/nilfs2/dat.c:293 nilfs_direct_propagate fs/nilfs2/direct.c:282 [inline] nilfs_direct_propagate+0x14e/0x320 fs/nilfs2/direct.c:256 nilfs_bmap_propagate+0x77/0x170 fs/nilfs2/bmap.c:345 nilfs_collect_file_data+0x49/0xd0 fs/nilfs2/segment.c:587 nilfs_segctor_apply_buffers+0x14a/0x470 fs/nilfs2/segment.c:1039 nilfs_segctor_scan_file+0x3f4/0x6f0 fs/nilfs2/segment.c:1088 nilfs_segctor_collect_blocks fs/nilfs2/segment.c:1197 [inline] nilfs_segctor_collect fs/nilfs2/segment.c:1524 [inline] nilfs_segctor_do_construct+0x267f/0x7200 fs/nilfs2/segment.c:2070 nilfs_segctor_construct+0x8e3/0xb30 fs/nilfs2/segment.c:2404 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2512 [inline] nilfs_segctor_thread+0x3c7/0xf30 fs/nilfs2/segment.c:2595 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.611 msecs