INFO: task syz.0.541:12843 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.541 state:D stack:24328 pid:12843 tgid:12842 ppid:11946 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 kernel/locking/rtmutex.c:1670 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline] __rt_mutex_slowlock_locked+0x1f84/0x25b0 kernel/locking/rtmutex.c:1787 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1502 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1576 __super_lock fs/super.c:60 [inline] super_lock+0x2d6/0x3d0 fs/super.c:122 __iterate_supers+0x120/0x240 fs/super.c:866 ksys_sync fs/sync.c:102 [inline] __ia32_sys_sync+0xa0/0x120 fs/sync.c:111 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: 0033:0x7fb9a71fce59 RSP: 002b:00007fb9a544e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007fb9a7475fa0 RCX: 00007fb9a71fce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fb9a7475fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb9a7476038 R14: 00007fb9a7475fa0 R15: 00007ffe26912718 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8dfc2fc0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 6 locks held by kworker/u8:6/108: #0: ffff88801b2a0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801b2a0938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000152fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000152fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f360860 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810 net/core/net_namespace.c:673 #3: ffff888029c00160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1102 [inline] #3: ffff888029c00160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline] #3: ffff888029c00160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:557 #4: ffff88803360a310 (&devlink->lock_key#43){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline] #4: ffff88803360a310 (&devlink->lock_key#43){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline] #4: ffff88803360a310 (&devlink->lock_key#43){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:557 #5: ffffffff8f36f6f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #5: ffffffff8f36f6f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2163 2 locks held by kworker/u8:7/155: #0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801a084138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90003927c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90003927c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 3 locks held by kworker/u8:10/1261: #0: ffff8880320d0938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff8880320d0938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc900062bfc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc900062bfc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f36f6f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f36f6f8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x123/0x16e0 net/ipv6/addrconf.c:4223 2 locks held by dhcpcd/5257: #0: ffff88805601a928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xe7/0xee0 net/netlink/af_netlink.c:2273 #1: ffffffff8f36f6f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f36f6f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dump_ifinfo+0xa74/0x14b0 net/core/rtnetlink.c:2554 2 locks held by getty/5353: #0: ffff888035d650a0 (&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 4 locks held by kworker/1:7/7726: 3 locks held by kworker/1:8/7754: #0: ffff88801a043938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801a043938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90004087c40 (rx_mode_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90004087c40 (rx_mode_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f36f6f8 (rtnl_mutex){+.+.}-{4:4}, at: netdev_rx_mode_work+0x19/0x450 net/core/dev_addr_lists.c:1346 3 locks held by syz-executor/10768: 1 lock held by syz.0.541/12843: #0: ffff8880296420d0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880296420d0 (&type->s_umount_key#69){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by udevd/13183: 1 lock held by syz.5.419/13217: #0: ffff8880296420d0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880296420d0 (&type->s_umount_key#69){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.5.419/13224: #0: ffff8880296420d0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880296420d0 (&type->s_umount_key#69){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.8.560/13421: #0: ffff8880296420d0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880296420d0 (&type->s_umount_key#69){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 1 lock held by syz.2.581/13693: #0: ffff8880296420d0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:60 [inline] #0: ffff8880296420d0 (&type->s_umount_key#69){++++}-{4:4}, at: super_lock+0x2d6/0x3d0 fs/super.c:122 5 locks held by syz-executor/14022: 1 lock held by syz-executor/14322: #0: ffffffff8f36f6f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f36f6f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f36f6f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a3/0x1bd0 net/core/rtnetlink.c:4150 3 locks held by syz.6.645/14490: 7 locks held by syz.6.645/14491: 3 locks held by syz.3.647/14536: 3 locks held by modprobe/14537: ============================================= 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 05/09/2026 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: 7726 Comm: kworker/1:7 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events_power_efficient wg_ratelimiter_gc_entries RIP: 0010:__rt_spin_lock kernel/locking/spinlock_rt.c:48 [inline] RIP: 0010:rt_spin_lock+0xa3/0x400 kernel/locking/spinlock_rt.c:57 Code: 31 c9 ff 75 08 e8 1d 3e 78 f6 48 83 c4 08 65 4c 8b 25 59 08 48 07 4d 8d bc 24 c4 04 00 00 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 <84> c0 0f 85 89 02 00 00 41 8b 17 c1 e2 08 48 c7 c7 e0 22 4d 8b be RSP: 0000:ffffc90003f179e0 EFLAGS: 00000a03 RAX: 0000000000000000 RBX: 1ffff920007e2f40 RCX: 0000000000000046 RDX: 00000000d0a61ec4 RSI: ffffffff8d8a1801 RDI: ffffffff8ba92a80 RBP: ffffc90003f17a98 R08: ffffffff85f834cd R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eab0a38 R12: ffff88802f39dd00 R13: dffffc0000000000 R14: ffffffff8eab09e0 R15: ffff88802f39e1c4 FS: 0000000000000000(0000) GS:ffff88812621a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4e85908068 CR3: 0000000025654000 CR4: 00000000003526f0 Call Trace: spin_lock include/linux/spinlock_rt.h:45 [inline] wg_ratelimiter_gc_entries+0x5d/0x470 drivers/net/wireguard/ratelimiter.c:63 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