INFO: task kworker/u4:4:1188 blocked for more than 143 seconds. Not tainted 5.15.138-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:4 state:D stack:19520 pid: 1188 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5026 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6372 schedule+0x11b/0x1f0 kernel/sched/core.c:6455 rwsem_down_write_slowpath+0xebb/0x15c0 kernel/locking/rwsem.c:1157 __down_write_common kernel/locking/rwsem.c:1284 [inline] __down_write kernel/locking/rwsem.c:1293 [inline] down_write+0x164/0x170 kernel/locking/rwsem.c:1542 f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:529 f2fs_write_inode+0x4c3/0x540 fs/f2fs/inode.c:727 write_inode fs/fs-writeback.c:1478 [inline] __writeback_single_inode+0x644/0xe30 fs/fs-writeback.c:1688 writeback_sb_inodes+0xbce/0x1a40 fs/fs-writeback.c:1913 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:1984 wb_writeback+0x465/0xc50 fs/fs-writeback.c:2089 wb_check_background_flush fs/fs-writeback.c:2155 [inline] wb_do_writeback fs/fs-writeback.c:2243 [inline] wb_workfn+0xd07/0x1130 fs/fs-writeback.c:2271 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c91f020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:4/1188: #0: ffff8881431ce938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283 #1: ffffc900054a7d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285 #2: ffff888078e600e0 (&type->s_umount_key#43){.+.+}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:418 #3: ffff888078561108 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x4d4/0x6a0 fs/f2fs/segment.c:529 2 locks held by getty/3261: #0: ffff888023c7f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900020a32e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158 4 locks held by syz-executor154/3523: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.138-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline] watchdog+0xe72/0xeb0 kernel/hung_task.c:295 kthread+0x3f6/0x4f0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3523 Comm: syz-executor154 Not tainted 5.15.138-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023 RIP: 0010:separate_irq_context kernel/locking/lockdep.c:4526 [inline] RIP: 0010:__lock_acquire+0xda4/0x1ff0 kernel/locking/lockdep.c:4995 Code: 89 d8 48 c1 e8 03 80 3c 38 00 74 12 48 89 df e8 12 48 67 00 48 bf 00 00 00 00 00 fc ff df 4c 89 3b 48 8b 44 24 40 0f b6 04 38 <84> c0 0f 85 54 0b 00 00 41 8b 5d 00 48 85 db 48 8b 0c 24 74 56 83 RSP: 0018:ffffc9000231ee00 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffff8880729c8b90 RCX: ffffffff81628f9f RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000 RBP: ffff8880729c8ae0 R08: dffffc0000000000 R09: fffffbfff1f79c3a R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000004 R13: ffff8880729c8ae8 R14: 1ffff1100e53915c R15: 4d5ea02f98a35e77 FS: 0000555555de2380(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffde4497338 CR3: 000000001ab22000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5622 down_read+0x45/0x2e0 kernel/locking/rwsem.c:1488 check_valid_map fs/f2fs/gc.c:881 [inline] gc_data_segment fs/f2fs/gc.c:1450 [inline] do_garbage_collect+0x20d8/0x7600 fs/f2fs/gc.c:1670 f2fs_gc+0x9e5/0x1ad0 fs/f2fs/gc.c:1764 f2fs_balance_fs+0x4e8/0x6a0 fs/f2fs/segment.c:530 f2fs_map_blocks+0x1989/0x28d0 fs/f2fs/data.c:1672 expand_inode_data+0x5ba/0x9d0 fs/f2fs/file.c:1697 f2fs_fallocate+0x35a/0x820 fs/f2fs/file.c:1787 vfs_fallocate+0x54a/0x6b0 fs/open.c:308 ksys_fallocate fs/open.c:331 [inline] __do_sys_fallocate fs/open.c:339 [inline] __se_sys_fallocate fs/open.c:337 [inline] __x64_sys_fallocate+0xb9/0x100 fs/open.c:337 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f467b501b59 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffdcde3ecd8 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f467b501b59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f467b57a5f0 R08: 0000555555de34c0 R09: 0000555555de34c0 R10: 0000000008800000 R11: 0000000000000246 R12: 00007ffdcde3ed00 R13: 00007ffdcde3ef28 R14: 431bde82d7b634db R15: 00007f467b54a03b INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.452 msecs