INFO: task kworker/u8:8:1060 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:8 state:D stack:20336 pid:1060 tgid:1060 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-7:3) Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x16ec/0x5620 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 io_schedule+0x7f/0xd0 kernel/sched/core.c:8110 TXN_SLEEP_DROP_LOCK fs/jfs/jfs_txnmgr.c:125 [inline] txBegin+0x27d/0xc00 fs/jfs/jfs_txnmgr.c:376 jfs_commit_inode+0x1b3/0x530 fs/jfs/inode.c:107 jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138 write_inode fs/fs-writeback.c:1584 [inline] __writeback_single_inode+0x75d/0x10e0 fs/fs-writeback.c:1827 writeback_sb_inodes+0x97f/0x1980 fs/fs-writeback.c:2056 wb_writeback+0x445/0xb00 fs/fs-writeback.c:2241 wb_do_writeback fs/fs-writeback.c:2388 [inline] wb_workfn+0x3fd/0xf20 fs/fs-writeback.c:2428 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz-executor:16962 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22344 pid:16962 tgid:16962 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x16ec/0x5620 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227 wb_wait_for_completion+0x3e8/0x790 fs/fs-writeback.c:227 __writeback_inodes_sb_nr+0x24c/0x2d0 fs/fs-writeback.c:2847 sync_filesystem+0xa2/0x250 fs/sync.c:54 generic_shutdown_super+0x77/0x2d0 fs/super.c:625 kill_block_super+0x44/0x90 fs/super.c:1725 deactivate_locked_super+0xbc/0x130 fs/super.c:476 cleanup_mnt+0x437/0x4d0 fs/namespace.c:1312 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0x193/0x680 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f40025de097 RSP: 002b:00007ffe786c0648 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f40026721ca RCX: 00007f40025de097 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe786c0700 RBP: 00007ffe786c0700 R08: 00007ffe786c1700 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe786c1790 R13: 00007f40026721ca R14: 0000000000114d08 R15: 00007ffe786c17d0 Showing all locks held in the system: 1 lock held by khungtaskd/39: #0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8100 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 7 locks held by kworker/u8:3/56: 2 locks held by kworker/u8:8/1060: #0: ffff88801f2af138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801f2af138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc900057b7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc900057b7c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 2 locks held by getty/5355: #0: ffff888036e540a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 5 locks held by kworker/u8:11/8273: 9 locks held by kworker/1:8/13266: 1 lock held by syz-executor/16962: #0: ffff8880568740d0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880568740d0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880568740d0 (&type->s_umount_key#53){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 1 lock held by udevd/17269: #0: ffff888037994480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 1 lock held by syz.0.1064/17979: #0: ffff8880568740d0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880568740d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.7.1099/18331: #0: ffff8880568740d0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880568740d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 4 locks held by syz-executor/18489: 1 lock held by syz.9.1105/18962: #0: ffff8880568740d0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880568740d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 9 locks held by syz-executor/19183: 1 lock held by syz.6.1119/19268: #0: ffff8880568740d0 (&type->s_umount_key#53){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880568740d0 (&type->s_umount_key#53){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 3 locks held by syz.8.1124/19311: 2 locks held by syz.5.1123/19316: 1 lock held by dhcpcd-run-hook/19319: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 13266 Comm: kworker/1:8 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: wg-crypt-wg2 wg_packet_tx_worker RIP: 0010:__bfs kernel/locking/lockdep.c:1753 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3908 [inline] RIP: 0010:__lock_acquire+0x1821/0x2cf0 kernel/locking/lockdep.c:5237 Code: 00 0f 83 8a 01 00 00 4e 8b 24 fd 00 d8 71 95 ff c0 25 ff 0f 00 00 89 05 cd 06 d2 13 4d 85 e4 0f 84 b2 01 00 00 49 8b 44 24 10 <48> 85 c0 0f 84 1c 0d 00 00 8b 0d b8 06 d2 13 39 48 5c 0f 84 67 ff RSP: 0000:ffffc90004dbe930 EFLAGS: 00000082 RAX: ffffffff931b9e18 RBX: 00000000000003cd RCX: ffffffff96267fa8 RDX: ffffffff96265458 RSI: ffff88802f34ac20 RDI: 00000000000003cd RBP: c40e5766fe8edfb2 R08: ffffc90004dbe8f8 R09: 0000000000000020 R10: dffffc0000000000 R11: ffffffff81a0a390 R12: ffffffff96267fa8 R13: ffff88802f34ac20 R14: ffff88802f349ec0 R15: 000000000000015c FS: 0000000000000000(0000) GS:ffff888126287000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa381b80000 CR3: 0000000093f86000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline] _raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166 lock_hrtimer_base kernel/time/hrtimer.c:191 [inline] hrtimer_start_range_ns+0xc3/0xef0 kernel/time/hrtimer.c:1489 enqueue_task+0x75/0x410 kernel/sched/core.c:2165 sched_change_end+0x22b/0x5f0 kernel/sched/core.c:11207 migrate_disable_switch kernel/sched/core.c:2425 [inline] __schedule+0x1889/0x5620 kernel/sched/core.c:7045 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8b0 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:queue_work_on+0x162/0x1d0 kernel/workqueue.c:2449 Code: 00 4d 85 ed 75 16 e8 7d 69 37 00 eb 15 e8 76 69 37 00 e8 31 92 8e 09 4d 85 ed 74 ea e8 67 69 37 00 fb 65 48 8b 05 ee 8c dc 10 <48> 3b 44 24 18 75 56 89 d8 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f RSP: 0000:ffffc90004dbefc8 EFLAGS: 00000246 RAX: cf09ec609975db00 RBX: ffffe8ffffc43c01 RCX: ffff88802f349ec0 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000100 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000100 R10: dffffc0000000000 R11: fffffbfff1f10e1f R12: 0000000000000000 R13: 0000000000000200 R14: 0000000000000000 R15: 0000000000800001 wg_queue_enqueue_per_device_and_peer drivers/net/wireguard/queueing.h:171 [inline] wg_packet_consume_data drivers/net/wireguard/receive.c:526 [inline] wg_packet_receive+0x17e3/0x2420 drivers/net/wireguard/receive.c:576 wg_receive+0x75/0xa0 drivers/net/wireguard/socket.c:325 udpv6_queue_rcv_one_skb+0xe85/0xfa0 net/ipv6/udp.c:842 udp6_unicast_rcv_skb+0x1ec/0x320 net/ipv6/udp.c:1027 ip6_protocol_deliver_rcu+0xdf8/0x1740 net/ipv6/ip6_input.c:479 ip6_input_finish+0x191/0x370 net/ipv6/ip6_input.c:534 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:545 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6202 [inline] __netif_receive_skb net/core/dev.c:6315 [inline] process_backlog+0x3ce/0xc60 net/core/dev.c:6666 __napi_poll+0xab/0x550 net/core/dev.c:7733 napi_poll net/core/dev.c:7796 [inline] net_rx_action+0x696/0xe00 net/core/dev.c:7953 handle_softirqs+0x1de/0x6d0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] __local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302 local_bh_enable include/linux/bottom_half.h:33 [inline] read_unlock_bh include/linux/rwlock_rt.h:73 [inline] wg_socket_send_skb_to_peer+0x199/0x200 drivers/net/wireguard/socket.c:183 wg_packet_create_data_done drivers/net/wireguard/send.c:251 [inline] wg_packet_tx_worker+0x1c8/0x7c0 drivers/net/wireguard/send.c:276 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245