INFO: task syz.1.255:8330 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.255 state:D stack:27776 pid:8330 tgid:8294 ppid:7281 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0x164/0x360 kernel/sched/core.c:7005 jfs_flush_journal+0x729/0xef0 fs/jfs/jfs_logmgr.c:1563 jfs_sync_fs+0x7d/0xa0 fs/jfs/super.c:649 sync_filesystem+0x1ce/0x250 fs/sync.c:66 jfs_reconfigure+0xc6/0xa00 fs/jfs/super.c:370 reconfigure_super+0x227/0x8a0 fs/super.c:1080 vfs_cmd_reconfigure fs/fsopen.c:268 [inline] vfs_fsconfig_locked+0x171/0x320 fs/fsopen.c:297 __do_sys_fsconfig fs/fsopen.c:463 [inline] __se_sys_fsconfig+0x6cf/0x820 fs/fsopen.c:350 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: 0033:0x7f835c58c799 RSP: 002b:00007f835a7c5028 EFLAGS: 00000246 ORIG_RAX: 00000000000001af RAX: ffffffffffffffda RBX: 00007f835c806090 RCX: 00007f835c58c799 RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000008 RBP: 00007f835c622bd9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f835c806128 R14: 00007f835c806090 R15: 00007ffdc6fd4708 Showing all locks held in the system: 1 lock held by khungtaskd/37: #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcd780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5551: #0: ffff888036e0f0a0 (&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 2 locks held by syz.1.255/8330: #0: ffff888031866a60 (&fc->uapi_mutex){+.+.}-{4:4}, at: __do_sys_fsconfig fs/fsopen.c:461 [inline] #0: ffff888031866a60 (&fc->uapi_mutex){+.+.}-{4:4}, at: __se_sys_fsconfig+0x6a3/0x820 fs/fsopen.c:350 #1: ffff888041b1c0d0 (&type->s_umount_key#80){++++}-{4:4}, at: vfs_cmd_reconfigure fs/fsopen.c:267 [inline] #1: ffff888041b1c0d0 (&type->s_umount_key#80){++++}-{4:4}, at: vfs_fsconfig_locked+0x169/0x320 fs/fsopen.c:297 2 locks held by syz-executor/9022: #0: ffff8880628ec0d0 (&type->s_umount_key#80){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880628ec0d0 (&type->s_umount_key#80){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880628ec0d0 (&type->s_umount_key#80){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e24f418 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443 2 locks held by udevd/9202: 1 lock held by udevd/9371: #0: ffff888022596ea8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1043 [inline] #0: ffff888022596ea8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:854 1 lock held by syz.1.384/9378: #0: ffff888041b1c0d0 (&type->s_umount_key#80){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888041b1c0d0 (&type->s_umount_key#80){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 3 locks held by udevd/9495: 12 locks held by syz-executor/10384: 2 locks held by syz.3.556/10601: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 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: 10384 Comm: syz-executor 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 78 56 95 ff c0 25 ff 0f 00 00 89 05 bd cd 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 a8 cd b6 13 39 48 5c 0f 84 67 ff RSP: 0018:ffffc900061fed88 EFLAGS: 00000086 RAX: ffffffff92f8eef8 RBX: 00000000000003cd RCX: ffffffff9605e148 RDX: ffffffff95e6a2e8 RSI: ffff88802ddde918 RDI: 00000000000003cd RBP: 1fbcf36ee2ccb78a R08: ffffc900061fed50 R09: 0000000000000020 R10: dffffc0000000000 R11: ffffffff81a07d70 R12: ffffffff9605e148 R13: ffff88802ddde918 R14: ffff88802ddddb80 R15: 0000000000000647 FS: 0000555578f05500(0000) GS:ffff88812643d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc491b0dc00 CR3: 0000000032baa000 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:6792 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7092 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 class_preempt_destructor include/linux/preempt.h:468 [inline] raw_spin_unlock_irqrestore_wake include/linux/sched/wake_q.h:102 [inline] rtlock_slowlock kernel/locking/rtmutex.c:1896 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x316/0x400 kernel/locking/spinlock_rt.c:57 spin_lock_bh include/linux/spinlock_rt.h:90 [inline] addrconf_ifdown+0x3b6/0x1aa0 net/ipv6/addrconf.c:3895 addrconf_notify+0x1bc/0x1050 net/ipv6/addrconf.c:-1 notifier_call_chain+0x1be/0x400 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] netif_close_many+0x2ae/0x420 net/core/dev.c:1804 netif_close_many_and_unlock net/core/dev.c:12314 [inline] unregister_netdevice_many_notify+0x81f/0x2360 net/core/dev.c:12378 unregister_netdevice_many net/core/dev.c:12477 [inline] unregister_netdevice_queue+0x31f/0x360 net/core/dev.c:12291 unregister_netdevice include/linux/netdevice.h:3408 [inline] nsim_destroy+0x1e5/0x680 drivers/net/netdevsim/netdev.c:1182 __nsim_dev_port_del+0x14d/0x1b0 drivers/net/netdevsim/dev.c:1528 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1540 [inline] nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1764 nsim_drv_remove+0x58/0x160 drivers/net/netdevsim/dev.c:1779 device_remove drivers/base/dd.c:571 [inline] __device_release_driver drivers/base/dd.c:1284 [inline] device_release_driver_internal+0x46f/0x870 drivers/base/dd.c:1307 bus_remove_device+0x352/0x440 drivers/base/bus.c:616 device_del+0x52b/0x900 drivers/base/core.c:3878 device_unregister+0x21/0xf0 drivers/base/core.c:3919 nsim_bus_dev_del drivers/net/netdevsim/bus.c:491 [inline] del_device_store+0x2b0/0x370 drivers/net/netdevsim/bus.c:244 kernfs_fop_write_iter+0x3b0/0x540 fs/kernfs/file.c:352 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x629/0xba0 fs/read_write.c:688 ksys_write+0x156/0x270 fs/read_write.c:740 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: 0033:0x7f686069cfce Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007ffc5e153a78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000555578f05500 RCX: 00007f686069cfce RDX: 0000000000000001 RSI: 00007ffc5e153b00 RDI: 0000000000000005 RBP: 00007f686077345c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffc5e153b00 R14: 00007f6861484620 R15: 0000000000000003