INFO: task syz-executor:8055 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:21928 pid:8055 tgid:8055 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x1681/0x54c0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563 rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1662 __rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1779 [inline] rt_mutex_slowlock+0x2dc/0x780 kernel/locking/rtmutex.c:1819 __rt_mutex_lock kernel/locking/rtmutex.c:1834 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:553 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 jfs_umount+0x2fb/0x3d0 fs/jfs/jfs_umount.c:124 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 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+0xed/0x480 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:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe3b6a6e017 RSP: 002b:00007fff93134968 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fe3b6b02120 RCX: 00007fe3b6a6e017 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff93134a20 RBP: 00007fff93134a20 R08: 00007fff93135a20 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff93135ab0 R13: 00007fe3b6b02120 R14: 000000000005428e R15: 00007fff93135af0 INFO: task syz-executor:8133 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:22488 pid:8133 tgid:8133 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x1681/0x54c0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563 rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1662 __rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1779 [inline] rt_mutex_slowlock+0x2dc/0x780 kernel/locking/rtmutex.c:1819 __rt_mutex_lock kernel/locking/rtmutex.c:1834 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:553 lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 jfs_umount+0x2fb/0x3d0 fs/jfs/jfs_umount.c:124 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194 generic_shutdown_super+0x13d/0x2d0 fs/super.c:646 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+0xed/0x480 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:238 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f387b27e017 RSP: 002b:00007fff05e06978 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f387b27e017 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff05e06a30 RBP: 00007fff05e06a30 R08: 00007fff05e07a30 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff05e07b20 R13: 00007f387b312120 R14: 0000000000056390 R15: 00007fff05e08bf0 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: 3 locks held by rcuc/0/20: 1 lock held by khungtaskd/37: #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:3/55: #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc9000121fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc9000121fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8f347300 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 #3: ffff888058609878 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_destruct+0x116/0x310 drivers/net/wireguard/device.c:249 3 locks held by kworker/u8:11/1829: #0: ffff888032c65138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff888032c65138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90006effc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90006effc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4206 2 locks held by getty/5348: #0: ffff8880370e60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 6 locks held by kworker/0:5/5690: 3 locks held by kworker/0:7/5725: #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90005627c40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90005627c40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 2 locks held by syz-executor/7552: #0: ffff888064d200d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888064d200d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888064d200d0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e455fb8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 3 locks held by kworker/0:8/7597: #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801a037938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90005f6fc40 (rx_mode_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90005f6fc40 (rx_mode_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: netdev_rx_mode_work+0x1c/0x450 net/core/dev_addr_lists.c:1312 2 locks held by syz-executor/7991: #0: ffff8880296d00d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880296d00d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880296d00d0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e455fb8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 2 locks held by syz-executor/8055: #0: ffff8880594960d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880594960d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880594960d0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e455fb8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 2 locks held by syz-executor/8133: #0: ffff8880508e60d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880508e60d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880508e60d0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e455fb8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 2 locks held by syz-executor/8334: #0: ffff8880645b00d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880645b00d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880645b00d0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e455fb8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 2 locks held by syz-executor/9706: #0: ffff8880257320d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880257320d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff8880257320d0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e455fb8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 1 lock held by syz.9.429/10168: #0: ffff888064d200d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff888064d200d0 (&type->s_umount_key#71){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 2 locks held by syz-executor/10259: #0: ffff888037ef40d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff888037ef40d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline] #0: ffff888037ef40d0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508 #1: ffffffff8e455fb8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1441 1 lock held by syz.3.474/10313: #0: ffff8880296d00d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880296d00d0 (&type->s_umount_key#71){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.2.482/10382: #0: ffff8880594960d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880594960d0 (&type->s_umount_key#71){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.0.494/10740: #0: ffff8880508e60d0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880508e60d0 (&type->s_umount_key#71){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz-executor/10811: #0: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f356038 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5039 5 locks held by syz-executor/11025: 1 lock held by udevd/11031: 4 locks held by syz.4.534/11231: 2 locks held by syz.8.539/11284: 3 locks held by dhcpcd-run-hook/11298: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5690 Comm: kworker/0:5 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: events_power_efficient neigh_periodic_work RIP: 0010:mark_usage kernel/locking/lockdep.c:4620 [inline] RIP: 0010:__lock_acquire+0x5ed/0x2cf0 kernel/locking/lockdep.c:5191 Code: 3b 9e f0 0b 00 00 0f 8c 0b ff ff ff 44 89 e0 38 04 24 76 16 e8 34 a4 fd 02 85 c0 74 0d 83 3d 9d 9e e8 0d 00 0f 84 0a 08 00 00 <83> 7c 24 10 00 0f 84 a8 00 00 00 41 8b 45 20 66 85 c0 0f 88 8c 00 RSP: 0018:ffffc90004da7740 EFLAGS: 00000097 RAX: 0000000000000003 RBX: ffff88803d3868f8 RCX: 0000000000000004 RDX: 0000000000000003 RSI: 0000000000000003 RDI: 0000000000000000 RBP: ffff88803d3868d8 R08: ffffffff8b1e646f R09: ffffffff8f481bf8 R10: dffffc0000000000 R11: fffffbfff1f11a5f R12: 0000000000000003 R13: ffff88803d3868d8 R14: ffff88803d385c40 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff88812617c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000561e151a3950 CR3: 00000000382d0000 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 rt_mutex_slowunlock+0xbf/0x8b0 kernel/locking/rtmutex.c:1426 spin_unlock_bh include/linux/spinlock_rt.h:115 [inline] neigh_periodic_work+0xc25/0xe90 net/core/neighbour.c:1038 process_one_work kernel/workqueue.c:3302 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466 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