INFO: task syz-executor:9363 blocked for more than 146 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:25800 pid:9363 tgid:9363 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 rtnl_net_lock include/linux/rtnetlink.h:130 [inline] inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7076 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7f5/0x990 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] __sys_sendto+0x41e/0x5d0 net/socket.c:2252 __do_sys_sendto net/socket.c:2259 [inline] __se_sys_sendto net/socket.c:2255 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2255 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: 0033:0x7ff56ae8e68e RSP: 002b:00007ffd52c046f8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055556099f500 RCX: 00007ff56ae8e68e RDX: 0000000000000028 RSI: 00007ff56bc84670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffd52c04774 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00007ff56bc84670 R15: 0000000000000000 INFO: task syz-executor:9369 blocked for more than 146 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:25800 pid:9369 tgid:9369 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 rtnl_net_lock include/linux/rtnetlink.h:130 [inline] inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7076 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x7f5/0x990 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] __sys_sendto+0x41e/0x5d0 net/socket.c:2252 __do_sys_sendto net/socket.c:2259 [inline] __se_sys_sendto net/socket.c:2255 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2255 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: 0033:0x7f3fd0e8e68e RSP: 002b:00007ffd31ad2db8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000555576a61500 RCX: 00007f3fd0e8e68e RDX: 0000000000000028 RSI: 00007f3fd1c84670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffd31ad2e34 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f3fd1c84670 R15: 0000000000000000 Showing all locks held in the system: 4 locks held by ktimers/0/16: 5 locks held by ktimers/1/29: 1 lock held by khungtaskd/37: #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:5/68: #0: ffff88803228f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88803228f938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000153fc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000153fc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4769 7 locks held by kworker/u8:7/1033: 5 locks held by kworker/u8:12/1431: 1 lock held by dhcpcd/5258: #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x2fb/0x1c50 net/ipv4/devinet.c:1120 2 locks held by getty/5349: #0: ffff8880328a20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:4/5714: 4 locks held by kworker/u8:17/8964: 4 locks held by kworker/u8:19/8987: 3 locks held by kworker/u9:3/9247: #0: ffff888036dc5938 ((wq_completion)hci8){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff888036dc5938 ((wq_completion)hci8){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000483fc40 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000483fc40 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff88803db50f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_open net/bluetooth/hci_core.c:426 [inline] #2: ffff88803db50f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_power_on+0x1a2/0x750 net/bluetooth/hci_core.c:920 3 locks held by kworker/u8:14/9298: #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: ffffc90003b8fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90003b8fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 1 lock held by syz-executor/9363: #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 1 lock held by syz-executor/9369: #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 1 lock held by syz-executor/9373: #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 2 locks held by kworker/0:2/9406: 1 lock held by syz-executor/9420: #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 1 lock held by syz-executor/9429: #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 1 lock held by syz-executor/9440: #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 1 lock held by syz-executor/9442: #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 1 lock held by syz-executor/9444: #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f5b0578 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978 3 locks held by kworker/u9:5/9451: #0: ffff88804c0f5138 ((wq_completion)hci9){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88804c0f5138 ((wq_completion)hci9){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90003d5fc40 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90003d5fc40 ((work_completion)(&hdev->power_on)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff888062178f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_open net/bluetooth/hci_core.c:426 [inline] #2: ffff888062178f80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_power_on+0x1a2/0x750 net/bluetooth/hci_core.c:920 ============================================= 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 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: 29 Comm: ktimers/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:rt_spin_lock+0xa/0x400 kernel/locking/spinlock_rt.c:55 Code: 0b 90 e9 fc fe ff ff cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 48 89 e5 41 57 <41> 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 80 00 00 00 49 89 fe 65 RSP: 0018:ffffc90000a3fc88 EFLAGS: 00000246 RAX: 1ffffffff1b66efb RBX: ffffffff8db377d8 RCX: ffff88801d2ebe00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8880b87284a0 RBP: ffffc90000a3fc90 R08: 0000000000000000 R09: 0000000000000100 R10: dffffc0000000000 R11: ffffffff81b1fbc0 R12: ffff888125d4c000 R13: 0000000000000008 R14: ffff8880b8728440 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888125d4c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055670cb68568 CR3: 00000000371b0000 CR4: 00000000003526f0 Call Trace: spin_lock include/linux/spinlock_rt.h:45 [inline] hrtimer_cpu_base_lock_expiry kernel/time/hrtimer.c:1650 [inline] hrtimer_run_softirq+0x7f/0x260 kernel/time/hrtimer.c:2109 handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] run_ktimerd+0x69/0x100 kernel/softirq.c:1151 smpboot_thread_fn+0x57c/0xa80 kernel/smpboot.c:160 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