INFO: task kworker/u8:4:62 blocked for more than 143 seconds. Not tainted 6.14.0-rc1-syzkaller-00028-g5c8c229261f1 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:4 state:D stack:20312 pid:62 tgid:62 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:9) Call Trace: context_switch kernel/sched/core.c:5377 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6764 __schedule_loop kernel/sched/core.c:6841 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6856 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6913 rwsem_down_write_slowpath+0xeee/0x13b0 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1d7/0x220 kernel/locking/rwsem.c:1578 f2fs_down_write fs/f2fs/f2fs.h:2191 [inline] f2fs_balance_fs+0x5a9/0x810 fs/f2fs/segment.c:454 f2fs_write_inode+0x3a7/0x540 fs/f2fs/inode.c:803 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x708/0x10d0 fs/fs-writeback.c:1745 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047 wb_writeback+0x427/0xb80 fs/fs-writeback.c:2158 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline] wb_do_writeback fs/fs-writeback.c:2315 [inline] wb_workfn+0xb94/0x1080 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e9387e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 4 locks held by kworker/u8:4/62: #0: ffff888020aba148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff888020aba148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc9000213fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000213fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 #2: ffff8880636d60e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff88807cbf5350 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2191 [inline] #3: ffff88807cbf5350 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_balance_fs+0x5a9/0x810 fs/f2fs/segment.c:454 2 locks held by kworker/u8:5/191: 3 locks held by kworker/0:2/975: #0: ffff88801ac80d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801ac80d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3317 #1: ffffc900038dfc60 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc900038dfc60 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3317 #2: ffffffff8e93dcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:302 [inline] #2: ffffffff8e93dcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:996 2 locks held by udevd/5199: 2 locks held by getty/5586: #0: ffff88814f3280a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:4/5873: 4 locks held by syz.9.521/9068: 5 locks held by kworker/u8:8/9667: 2 locks held by syz.5.765/10490: #0: ffff8880636d60e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880636d60e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880252947d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880252947d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.5.765/10491: #0: ffff8880636d60e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880636d60e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880252947d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880252947d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.5.765/10496: #0: ffff8880636d60e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880636d60e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880252947d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880252947d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.7.809/10736: #0: ffff8880636d60e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880636d60e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880252947d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880252947d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 3 locks held by syz-executor/10766: #0: ffff88806c92cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:480 [inline] #0: ffff88806c92cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2677 #1: ffff88806c92c078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x5c8/0x11c0 net/bluetooth/hci_sync.c:5185 #2: ffffffff8e93dcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline] #2: ffffffff8e93dcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:996 2 locks held by syz-executor/10791: #0: ffff8880304fcd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:480 [inline] #0: ffff8880304fcd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2677 #1: ffff8880304fc078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x5c8/0x11c0 net/bluetooth/hci_sync.c:5185 2 locks held by syz.2.822/10836: #0: ffffffff8f050aa8 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline] #0: ffffffff8f050aa8 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x42f/0x650 block/bio.c:1662 #1: ffffffff8e93db80 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3741 2 locks held by syz.9.823/10838: #0: ffff888027c20d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:480 [inline] #0: ffff888027c20d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2677 #1: ffff888027c20078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x5c8/0x11c0 net/bluetooth/hci_sync.c:5185 2 locks held by syz.0.819/10851: #0: ffff88805ccc4d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:480 [inline] #0: ffff88805ccc4d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x203/0x510 net/bluetooth/hci_core.c:2677 #1: ffff88805ccc4078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x5c8/0x11c0 net/bluetooth/hci_sync.c:5185 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc1-syzkaller-00028-g5c8c229261f1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5199 Comm: udevd Not tainted 6.14.0-rc1-syzkaller-00028-g5c8c229261f1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:202 [inline] RIP: 0010:unwind_next_frame+0x13f/0x22d0 arch/x86/kernel/unwind_orc.c:494 Code: 20 84 c0 0f 85 b8 19 00 00 4c 0f be 7d 00 48 8b 44 24 30 42 80 3c 20 00 48 8b 5c 24 18 74 08 48 89 df e8 74 ba b7 00 4c 03 3b <49> ff cf 4c 89 6c 24 08 4c 89 74 24 68 48 89 2c 24 0f 84 0c 01 00 RSP: 0018:ffffc900032a79b0 EFLAGS: 00000286 RAX: 1ffff92000654f59 RBX: ffffc900032a7ac8 RCX: ffffffff8bf0e100 RDX: dffffc0000000000 RSI: ffffffff81000130 RDI: ffffffff816bb3f0 RBP: ffffc900032a7ab5 R08: 0000000000000006 R09: ffffc900032a7b70 R10: ffffc900032a7ad0 R11: ffffffff81ab1d60 R12: dffffc0000000000 R13: ffffc900032a7a80 R14: ffffffff81000130 R15: ffffffff81000130 FS: 00007fcf3bd73c80(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555c960808 CR3: 000000007c1c0000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4171 getname_flags+0xb7/0x540 fs/namei.c:139 getname fs/namei.c:223 [inline] __do_sys_unlink fs/namei.c:4637 [inline] __se_sys_unlink fs/namei.c:4635 [inline] __x64_sys_unlink+0x3a/0x50 fs/namei.c:4635 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcf3b917da7 Code: f0 ff ff 73 01 c3 48 8b 0d 7e 90 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 57 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 51 90 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007ffc82a1cdf8 EFLAGS: 00000202 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcf3b917da7 RDX: 0000000000000000 RSI: 000000001e19b040 RDI: 0000563d3a58d0d8 RBP: 0000563d3ac810c0 R08: 000000001e1a10ea R09: 7fffffffffffffff R10: 00007fcf3be7a038 R11: 0000000000000202 R12: 0000000000000bb8 R13: 0000563d3ac838f0 R14: 0000000000000000 R15: 0000000000000000