INFO: task syz.6.1908:22200 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.1908 state:D stack:25664 pid:22200 tgid:22199 ppid:13352 task_flags:0x400140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2cc/0x5e0 kernel/sched/completion.c:153 kthread_flush_worker+0x138/0x1a0 kernel/kthread.c:1579 __alloc_workqueue+0xfed/0x1e90 kernel/workqueue.c:5861 alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:5884 btrfs_alloc_workqueue+0x1ec/0x2d0 fs/btrfs/async-thread.c:112 btrfs_init_workqueues+0xb0/0x680 fs/btrfs/disk-io.c:1920 open_ctree+0x1598/0x4220 fs/btrfs/disk-io.c:3447 btrfs_fill_super fs/btrfs/super.c:981 [inline] btrfs_get_tree_super fs/btrfs/super.c:1944 [inline] btrfs_get_tree_subvol fs/btrfs/super.c:2087 [inline] btrfs_get_tree+0x1061/0x1930 fs/btrfs/super.c:2121 vfs_get_tree+0x92/0x2a0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline] do_new_mount_fc fs/namespace.c:3763 [inline] do_new_mount+0x341/0xd30 fs/namespace.c:3839 do_mount fs/namespace.c:4172 [inline] __do_sys_mount fs/namespace.c:4361 [inline] __se_sys_mount+0x31d/0x420 fs/namespace.c:4338 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f91b102da0a RSP: 002b:00007f91af285e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f91af285ee0 RCX: 00007f91b102da0a RDX: 0000200000005100 RSI: 0000200000000040 RDI: 00007f91af285ea0 RBP: 0000200000005100 R08: 00007f91af285ee0 R09: 0000000000800810 R10: 0000000000800810 R11: 0000000000000246 R12: 0000200000000040 R13: 00007f91af285ea0 R14: 000000000000510a R15: 0000200000000140 Showing all locks held in the system: 4 locks held by pr/legacy/17: 1 lock held by khungtaskd/38: #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5550: #0: ffff888036ea70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by udevd/6562: #0: ffff8880227ca228 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff8880227ca228 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:854 2 locks held by udevd/8732: 1 lock held by udevd/10082: 2 locks held by kworker/u8:13/11717: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90006767c40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90006767c40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 5 locks held by napi/wg1-0/13728: 1 lock held by syz-executor/15312: 2 locks held by kworker/u8:2/21361: #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90011b7fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90011b7fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 1 lock held by syz.6.1908/22200: #0: ffff88807a2d40d0 (&type->s_umount_key#60/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 8 locks held by syz-executor/24428: #0: ffff8880114f4480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff8880114f4480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684 #1: ffff88803c20e078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343 #2: ffff88802902ba58 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88802902ba58 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344 #3: ffffffff8e9c85f8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff88803ba6d0d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88803ba6d0d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline] #4: ffff88803ba6d0d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1304 #5: ffff88803d158300 (&devlink->lock_key#16){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1778 #6: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1177 #7: ffff888036570ea0 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2784 [inline] #7: ffff888036570ea0 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x583/0x2360 net/core/dev.c:12374 1 lock held by syz.4.2112/24560: 2 locks held by syz.9.2111/24569: #0: ffff88803fcb40d0 (&type->s_umount_key#54/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xac0 fs/super.c:345 #1: ffffffff8dc6bab8 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5279 [inline] #1: ffffffff8dc6bab8 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0x9ef/0x1e90 kernel/workqueue.c:5832 1 lock held by rm/24592: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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:161 [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:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 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: 13728 Comm: napi/wg1-0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 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 c0 88 56 95 ff c0 25 ff 0f 00 00 89 05 6d b7 b6 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 58 b7 b6 13 39 48 5c 0f 84 67 ff RSP: 0018:ffffc90003c572c8 EFLAGS: 00000086 RAX: ffffffff92fea6a0 RBX: 00000000000003cd RCX: ffffffff9601d9e8 RDX: ffffffff95e5fff8 RSI: ffff88801e7c8c80 RDI: 00000000000003cd RBP: bc3f9163dc441ef4 R08: ffffc90003c57290 R09: 0000000000000020 R10: dffffc0000000000 R11: ffffffff81a0a3c0 R12: ffffffff9601d9e8 R13: ffff88801e7c8c80 R14: ffff88801e7c8000 R15: 00000000000000b4 FS: 0000000000000000(0000) GS:ffff88812643c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f78116a1000 CR3: 000000006bb6a000 CR4: 00000000003526f0 Call Trace: lock_acquire+0xf0/0x2e0 kernel/locking/lockdep.c:5868 _raw_spin_lock_nested+0x32/0x50 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 raw_spin_rq_lock kernel/sched/sched.h:1615 [inline] _task_rq_lock+0xbc/0x470 kernel/sched/core.c:747 class_task_rq_lock_constructor kernel/sched/sched.h:1917 [inline] migrate_disable_switch kernel/sched/core.c:2366 [inline] __schedule+0x16d3/0x5240 kernel/sched/core.c:6795 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7238 irqentry_exit+0x599/0x620 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2d7/0x3d0 kernel/locking/lockdep.c:5893 Code: 1d ae 10 00 00 00 00 eb b5 e8 a5 79 82 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 15 d7 ad 10 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 72 fb cc RSP: 0018:ffffc90003c57870 EFLAGS: 00000282 RAX: ec45087a6ccc9d00 RBX: 0000000000000206 RCX: 0000000000000046 RDX: 000000001538c6fc RSI: ffffffff8d7bd735 RDI: ffffffff8ba66b00 RBP: ffff88801e7c8c30 R08: ffffffff8b2531d0 R09: ffffffff8ddcb980 R10: 0000000000000000 R11: ffffed100661f824 R12: 0000000000000004 R13: 0000000000000004 R14: ffff8880330fc0e8 R15: ffff88801e7c8000 rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80 spin_unlock_bh include/linux/spinlock_rt.h:115 [inline] counter_validate drivers/net/wireguard/receive.c:329 [inline] wg_packet_rx_poll+0x61c/0x24e0 drivers/net/wireguard/receive.c:461 __napi_poll+0xaf/0x580 net/core/dev.c:7692 napi_threaded_poll_loop+0x3b2/0x6f0 net/core/dev.c:7812 napi_threaded_poll+0x335/0x490 net/core/dev.c:7867 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245