INFO: task syz.3.800:9957 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.800 state:D stack:28568 pid:9957 tgid:9956 ppid:9508 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7020 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 sync_bdevs+0x27e/0x470 block/bdev.c:1305 ksys_sync+0xb9/0x150 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6cd5b8f749 RSP: 002b:00007f6cd6a9c038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f6cd5de5fa0 RCX: 00007f6cd5b8f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f6cd5de5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6cd5de6038 R14: 00007f6cd5de5fa0 R15: 00007ffdf555a518 INFO: task syz.3.800:9959 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.800 state:D stack:28568 pid:9959 tgid:9956 ppid:9508 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7020 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 sync_bdevs+0x27e/0x470 block/bdev.c:1305 ksys_sync+0xb9/0x150 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6cd5b8f749 RSP: 002b:00007f6cd6a7b038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f6cd5de6090 RCX: 00007f6cd5b8f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f6cd5de6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6cd5de6128 R14: 00007f6cd5de6090 R15: 00007ffdf555a518 INFO: task syz.3.800:9961 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.800 state:D stack:27448 pid:9961 tgid:9956 ppid:9508 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5258 [inline] __schedule+0x150e/0x5070 kernel/sched/core.c:6866 __schedule_loop kernel/sched/core.c:6948 [inline] schedule+0x165/0x360 kernel/sched/core.c:6963 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7020 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 sync_bdevs+0x27e/0x470 block/bdev.c:1305 ksys_sync+0xb9/0x150 fs/sync.c:105 __ia32_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6cd5b8f749 RSP: 002b:00007f6cd6a5a038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f6cd5de6180 RCX: 00007f6cd5b8f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f6cd5de6180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6cd5de6218 R14: 00007f6cd5de6180 R15: 00007ffdf555a518 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e13f2e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:4/60: #0: ffff88801baa7148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc9000211fb80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffffffff8f504e10 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7a0 net/core/net_namespace.c:670 #3: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: wiphy_unregister+0x244/0xab0 net/wireless/core.c:1180 2 locks held by getty/5580: #0: ffff88803049e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211 1 lock held by udevd/5822: #0: ffff88814231a358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:962 3 locks held by kworker/1:4/5881: #0: ffff88813fe15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc9000459fb80 ((work_completion)(&tn->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: tipc_net_finalize_work+0x1e/0x90 net/tipc/net.c:148 3 locks held by kworker/u8:14/6019: #0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3254 #1: ffffc90004eafb80 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3255 #2: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 1 lock held by syz.3.800/9957: #0: ffff88814231a358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1305 1 lock held by syz.3.800/9959: #0: ffff88814231a358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1305 1 lock held by syz.3.800/9961: #0: ffff88814231a358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0x27e/0x470 block/bdev.c:1305 2 locks held by syz.6.1268/12221: #0: ffffffff8f504e10 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577 #1: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: cangw_pernet_exit_batch+0x20/0x90 net/can/gw.c:1288 6 locks held by syz.2.1269/12239: #0: ffffffff8f57a0f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffff8880622620e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #1: ffff8880622620e8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #1: ffff8880622620e8 (&dev->mutex){....}-{4:4}, at: devlink_get_from_attrs_lock+0x240/0x3a0 net/devlink/netlink.c:198 #2: ffff888062261250 (&devlink->lock_key#14){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #2: ffff888062261250 (&devlink->lock_key#14){+.+.}-{4:4}, at: devlink_get_from_attrs_lock+0x24f/0x3a0 net/devlink/netlink.c:198 #3: ffffffff8f512448 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1175 #4: ffff888034840d48 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2786 [inline] #4: ffff888034840d48 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline] #4: ffff888034840d48 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1198/0x2340 net/core/dev.c:12387 #5: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #5: ffffffff8e144e38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:956 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [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:363 [inline] watchdog+0xe40/0xe90 kernel/hung_task.c:557 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12239 Comm: syz.2.1269 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:240 [inline] RIP: 0010:rb_erase+0xeb/0xe60 lib/rbtree.c:443 Code: 89 e7 49 89 c4 48 8d 58 10 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 d3 48 89 df e8 57 6a cf f6 eb c9 <4c> 89 e8 48 c1 e8 03 48 bd 00 00 00 00 00 fc ff df 80 3c 28 00 74 RSP: 0018:ffffc90000007ca8 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff8880b8628310 RCX: dffffc0000000000 RDX: 0000000000010000 RSI: ffff8880b8628310 RDI: ffffc9000409fd48 RBP: 1ffff92000813faa R08: ffffffff8fa22f77 R09: 1ffffffff1f445ee R10: dffffc0000000000 R11: fffffbfff1f445ef R12: 0000000000000000 R13: ffffc9000409fd40 R14: ffffc9000409fd50 R15: 0000000000000000 FS: 00007ff8a918f6c0(0000) GS:ffff888125c25000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555769fe5c8 CR3: 0000000025bce000 CR4: 00000000003526f0 Call Trace: rb_erase_cached include/linux/rbtree.h:154 [inline] timerqueue_del+0xae/0x100 lib/timerqueue.c:57 __remove_hrtimer kernel/time/hrtimer.c:1114 [inline] __run_hrtimer kernel/time/hrtimer.c:1757 [inline] __hrtimer_run_queues+0x364/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2037 [inline] RIP: 0010:vprintk_emit+0x4d0/0x5f0 kernel/printk/printk.c:2425 Code: 0f 84 34 ff ff ff e8 4f 71 20 00 fb eb 44 e8 47 71 20 00 e8 f2 6a bc 09 4d 85 f6 74 94 e8 38 71 20 00 fb 48 c7 c7 e0 31 13 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 28 26 RSP: 0018:ffffc90004d7e5e0 EFLAGS: 00000287 RAX: ffffffff81a14728 RBX: ffffffff81a14581 RCX: 0000000000080000 RDX: ffffc90010fa3000 RSI: 000000000003de80 RDI: ffffffff8e1331e0 RBP: ffffc90004d7e6f0 R08: ffffffff8fa22f77 R09: 1ffffffff1f445ee R10: dffffc0000000000 R11: fffffbfff1f445ef R12: 0000000000000000 R13: 000000000000005b R14: 0000000000000200 R15: 1ffff920009afcc0 dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4914 dev_printk_emit+0xe0/0x130 drivers/base/core.c:4925 __netdev_printk+0x3e1/0x480 net/core/dev.c:12920 netdev_info+0x10a/0x160 net/core/dev.c:12975 nsim_udp_tunnel_unset_port+0x2d0/0x530 drivers/net/netdevsim/udp_tunnels.c:59 udp_tunnel_nic_device_sync_one net/ipv4/udp_tunnel_nic.c:-1 [inline] udp_tunnel_nic_device_sync_by_port net/ipv4/udp_tunnel_nic.c:249 [inline] __udp_tunnel_nic_device_sync+0xb0f/0x14d0 net/ipv4/udp_tunnel_nic.c:292 udp_tunnel_nic_flush+0x2cc/0x670 net/ipv4/udp_tunnel_nic.c:694 udp_tunnel_nic_unregister net/ipv4/udp_tunnel_nic.c:901 [inline] udp_tunnel_nic_netdevice_event+0xfbf/0x17e0 net/ipv4/udp_tunnel_nic.c:942 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2269 [inline] call_netdevice_notifiers net/core/dev.c:2283 [inline] unregister_netdevice_many_notify+0x1867/0x2340 net/core/dev.c:12400 unregister_netdevice_many net/core/dev.c:12463 [inline] unregister_netdevice_queue+0x317/0x350 net/core/dev.c:12277 unregister_netdevice include/linux/netdevice.h:3411 [inline] nsim_destroy+0x1e5/0x680 drivers/net/netdevsim/netdev.c:1180 __nsim_dev_port_del+0x14d/0x1b0 drivers/net/netdevsim/dev.c:1529 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1541 [inline] nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1764 nsim_dev_reload_down+0x8a/0xc0 drivers/net/netdevsim/dev.c:1039 devlink_reload+0x1b6/0x8d0 net/devlink/dev.c:461 devlink_nl_reload_doit+0xa8d/0xc60 net/devlink/dev.c:584 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737 __sock_sendmsg net/socket.c:752 [inline] ____sys_sendmsg+0x577/0x880 net/socket.c:2610 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2664 __sys_sendmsg net/socket.c:2696 [inline] __do_sys_sendmsg net/socket.c:2701 [inline] __se_sys_sendmsg net/socket.c:2699 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2699 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff8a838f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff8a918f038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007ff8a85e5fa0 RCX: 00007ff8a838f749 RDX: 0000000000000000 RSI: 0000200000000080 RDI: 0000000000000006 RBP: 00007ff8a8413f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff8a85e6038 R14: 00007ff8a85e5fa0 R15: 00007ffcbe9cdc18