INFO: task kworker/u4:4:473 blocked for more than 140 seconds. Not tainted 4.19.211-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:4 D25888 473 2 0x80000000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3619 __mutex_lock_common kernel/locking/mutex.c:1016 [inline] __mutex_lock+0x5f0/0x1190 kernel/locking/mutex.c:1078 f2fs_balance_fs+0x709/0xd80 fs/f2fs/segment.c:512 f2fs_write_inode+0x500/0x600 fs/f2fs/inode.c:630 write_inode fs/fs-writeback.c:1244 [inline] __writeback_single_inode+0x733/0x11d0 fs/fs-writeback.c:1442 writeback_sb_inodes+0x537/0xef0 fs/fs-writeback.c:1647 __writeback_inodes_wb+0xc6/0x280 fs/fs-writeback.c:1716 wb_writeback+0x841/0xcc0 fs/fs-writeback.c:1822 wb_check_old_data_flush fs/fs-writeback.c:1924 [inline] wb_do_writeback fs/fs-writeback.c:1977 [inline] wb_workfn+0x8ba/0x1250 fs/fs-writeback.c:2006 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Showing all locks held in the system: 4 locks held by kworker/u4:4/473: #0: 00000000f935aac2 ((wq_completion)"writeback"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2124 #1: 00000000c2ee76a0 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2128 #2: 0000000087a89b35 (&type->s_umount_key#51){++++}, at: trylock_super+0x1d/0x100 fs/super.c:412 #3: 00000000eb66924e (&sbi->gc_mutex){+.+.}, at: f2fs_balance_fs+0x709/0xd80 fs/f2fs/segment.c:512 1 lock held by khungtaskd/1559: #0: 000000008b8c3ee5 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441 1 lock held by in:imklog/7818: #0: 000000006d2c5b0a (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 2 locks held by syz-executor.0/10626: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1559 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4687 Comm: systemd-journal Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023 RIP: 0010:__orc_find+0xaf/0xf0 arch/x86/kernel/unwind_orc.c:56 Code: d8 48 39 c1 73 b0 4c 8d 63 fc 49 39 ec 73 b3 4d 29 ee 49 c1 fe 02 4b 8d 04 76 48 8d 04 46 48 83 c4 10 5b 5d 41 5c 41 5d 41 5e <41> 5f c3 48 83 c4 10 31 c0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 89 RSP: 0018:ffff8880a117f9b0 EFLAGS: 00000286 RAX: ffffffff8b8cd904 RBX: 1ffff1101422ff41 RCX: ffffffff81007718 RDX: 0000000000000000 RSI: ffffffff8b8cd904 RDI: ffffffff8b30530c RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8b8cd904 R10: ffff8880a117fb4f R11: 0000000000074071 R12: ffff8880a117fb38 R13: ffff8880a117fb25 R14: ffff8880a117faf0 R15: dffffc0000000000 FS: 00007f1a7080c8c0(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4918a4d718 CR3: 00000000a16c1000 CR4: 00000000003406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: orc_find arch/x86/kernel/unwind_orc.c:159 [inline] unwind_next_frame+0x339/0x1400 arch/x86/kernel/unwind_orc.c:422 __save_stack_trace+0x9f/0x190 arch/x86/kernel/stacktrace.c:44 save_stack mm/kasan/kasan.c:448 [inline] set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:553 slab_post_alloc_hook mm/slab.h:445 [inline] slab_alloc mm/slab.c:3397 [inline] kmem_cache_alloc+0x110/0x370 mm/slab.c:3557 getname_flags+0xce/0x590 fs/namei.c:140 do_sys_open+0x26c/0x520 fs/open.c:1079 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f1a6fd9b840 Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24 RSP: 002b:00007fffd38ce458 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fffd38ce760 RCX: 00007f1a6fd9b840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 0000560db9176700 RBP: 000000000000000d R08: 000000000000c0ff R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000560db9170040 R14: 00007fffd38ce720 R15: 0000560db9176750