INFO: task syz-executor:14062 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-executor state:D stack:22288 pid:14062 tgid:14062 ppid:1 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7607 rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670 __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline] rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827 __rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline] __mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline] mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578 del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 kernfs_fop_write_iter+0x3a5/0x540 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61e/0xbb0 fs/read_write.c:687 ksys_write+0x156/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa9ab20e90e RSP: 002b:00007fffe24219b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000055556169e500 RCX: 00007fa9ab20e90e RDX: 0000000000000001 RSI: 00007fffe2421a40 RDI: 0000000000000005 RBP: 00007fa9ab2e58a7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fffe2421a40 R14: 00007fa9ac004620 R15: 0000000000000003 Showing all locks held in the system: 6 locks held by kworker/u8:0/12: 6 locks held by ksoftirqd/0/15: 6 locks held by ksoftirqd/1/30: 1 lock held by khungtaskd/37: #0: ffffffff8e1c3040 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1c3040 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e1c3040 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by dhcpcd/5244: #0: ffff88805efae928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe7/0xee0 net/netlink/af_netlink.c:2273 #1: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dump_ifinfo+0xa74/0x14b0 net/core/rtnetlink.c:2562 2 locks held by getty/5335: #0: ffff888034d350a0 (&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+0x460/0x1360 drivers/tty/n_tty.c:2211 2 locks held by kworker/u8:19/7875: #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000592fc40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000592fc40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 7 locks held by syz-executor/13976: #0: ffff8880366f6500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff8880366f6500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff88803768fc78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff8880298fba58 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff8880298fba58 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ee21598 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184 #4: ffff88802c417160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff88802c417160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1073 #5: ffff8880358fa310 (&devlink->lock_key#23){+.+.}-{4:4}, at: nsim_drv_probe+0xfc/0xc00 drivers/net/netdevsim/dev.c:1658 #6: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1058 [inline] #6: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: nsim_create+0x87f/0x1160 drivers/net/netdevsim/netdev.c:1152 4 locks held by syz-executor/14062: #0: ffff8880366f6500 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2733 [inline] #0: ffff8880366f6500 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #1: ffff88805f076078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 #2: ffff8880298fb968 (kn->active#51){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:73 [inline] #2: ffff8880298fb968 (kn->active#51){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22c/0x540 fs/kernfs/file.c:337 #3: ffffffff8ee21598 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234 3 locks held by kworker/u8:7/14460: #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90003f37c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90003f37c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 5 locks held by kworker/u8:11/14461: 1 lock held by syz-executor/14482: #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3442 1 lock held by syz-executor/14489: #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 1 lock held by syz-executor/14494: #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 1 lock held by syz-executor/14500: #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4158 1 lock held by syz-executor/14533: #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x767/0xc00 net/core/rtnetlink.c:7082 1 lock held by syz-executor/14580: #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5ac938 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 1 lock held by modprobe/14587: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 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+0xfd7/0x1030 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: 12 Comm: kworker/u8:0 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: netns cleanup_net RIP: 0010:get_dep_list kernel/locking/lockdep.c:1572 [inline] RIP: 0010:__bfs kernel/locking/lockdep.c:1814 [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+0x1873/0x2ce0 kernel/locking/lockdep.c:5237 Code: 90 4d 8b 6f 10 4c 8b 74 24 10 48 8b 34 24 48 89 df 49 8b 45 60 89 c3 83 e3 55 41 80 7f 2b 00 48 0f 44 d8 48 09 fb 49 8b 55 30 <49> 83 c5 30 48 89 df 4c 39 ea 0f 84 a4 fe ff ff 4c 89 7a 30 44 8b RSP: 0018:ffffc900001170e0 EFLAGS: 00000002 RAX: 0000000000000144 RBX: 00000000000003cd RCX: 0000000000000008 RDX: ffffffff963ff7b8 RSI: ffff88801ca80d70 RDI: 00000000000003cd RBP: 0fbdc59ced7fd5ed R08: ffffc900001170a8 R09: 0000000000000020 R10: 0000000000000000 R11: ffffffff81a1c840 R12: 000000000000024e R13: ffffffff934ed080 R14: ffff88801ca80000 R15: ffffffff9642d958 FS: 0000000000000000(0000) GS:ffff888125d3a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f936ba00440 CR3: 00000000384da000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 seqcount_lockdep_reader_access+0x55/0x100 include/linux/seqlock.h:73 ktime_get+0x45/0x220 kernel/time/timekeeping.c:971 clockevents_program_event+0x290/0x630 kernel/time/clockevents.c:363 hrtimer_rearm kernel/time/hrtimer.c:2141 [inline] __hrtimer_rearm_deferred+0x26f/0x430 kernel/time/hrtimer.c:2161 hrtimer_rearm_deferred_tif include/linux/hrtimer_rearm.h:53 [inline] hrtimer_rearm_deferred include/linux/hrtimer_rearm.h:62 [inline] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:505 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:542 [inline] irqentry_exit+0x8cc/0x910 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198 Code: f7 e8 cd 52 59 f6 f7 c3 00 02 00 00 74 05 e8 40 43 85 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 b4 6f 4b f6 65 8b 05 ad 9b 55 07 85 c0 74 18 5b 41 5e e9 51 3d RSP: 0018:ffffc90000117528 EFLAGS: 00000206 RAX: 0000000000000002 RBX: 0000000000000246 RCX: 0000000080000002 RDX: 0000000000000006 RSI: ffffffff8d884ffb RDI: 0000000000000001 RBP: ffffc900001175e8 R08: ffffffff8faf9337 R09: 1ffffffff1f5f266 R10: dffffc0000000000 R11: fffffbfff1f5f267 R12: 1ffff92000022eb1 R13: 0000000000000246 R14: ffff88806211f1e8 R15: ffffc90000117580 raw_spin_unlock_irqrestore_wake include/linux/sched/wake_q.h:97 [inline] rtlock_slowlock kernel/locking/rtmutex.c:1923 [inline] rtlock_lock kernel/locking/spinlock_rt.c:43 [inline] __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline] rt_spin_lock+0x17a/0x400 kernel/locking/spinlock_rt.c:57 spin_lock include/linux/spinlock_rt.h:45 [inline] fast_dput+0x29c/0x670 fs/dcache.c:947 dput+0x30/0x60 fs/dcache.c:1040 debugfs_remove+0x5b/0x70 fs/debugfs/inode.c:781 nsim_destroy+0x2d1/0x800 drivers/net/netdevsim/netdev.c:1199 __nsim_dev_port_del+0x14e/0x200 drivers/net/netdevsim/dev.c:1547 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1561 [inline] nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1785 nsim_dev_reload_down+0x8a/0xc0 drivers/net/netdevsim/dev.c:1038 devlink_reload+0x1c5/0x890 net/devlink/dev.c:462 devlink_pernet_pre_exit+0x1ff/0x420 net/devlink/core.c:560 ops_pre_exit_list net/core/net_namespace.c:161 [inline] ops_undo_list+0x17d/0x8d0 net/core/net_namespace.c:234 cleanup_net+0x575/0x810 net/core/net_namespace.c:702 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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