INFO: task syz.2.4421:22159 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.4421 state:D stack:25904 pid:22159 tgid:22155 ppid:17761 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ea/0x5050 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 nfsd_nl_rpc_status_get_dumpit+0xdc/0x1410 fs/nfsd/nfsctl.c:1483 genl_dumpit+0x10b/0x1b0 net/netlink/genetlink.c:1027 netlink_dump+0x722/0xe80 net/netlink/af_netlink.c:2325 __netlink_dump_start+0x5cb/0x7e0 net/netlink/af_netlink.c:2440 genl_family_rcv_msg_dumpit+0x213/0x310 net/netlink/genetlink.c:1076 genl_family_rcv_msg net/netlink/genetlink.c:1192 [inline] genl_rcv_msg+0x5e8/0x7a0 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x232/0x4b0 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+0x80f/0x9b0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd6f999aeb9 RSP: 002b:00007fd6fa862028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fd6f9c15fa0 RCX: 00007fd6f999aeb9 RDX: 0000000000000800 RSI: 0000200000000180 RDI: 0000000000000003 RBP: 00007fd6f9a08c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd6f9c16038 R14: 00007fd6f9c15fa0 R15: 00007ffdc4850ab8 INFO: task syz.2.4421:22165 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.4421 state:D stack:23808 pid:22165 tgid:22155 ppid:17761 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x14ea/0x5050 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7021 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 netlink_dump+0xe4/0xe80 net/netlink/af_netlink.c:2267 netlink_recvmsg+0x690/0xa50 net/netlink/af_netlink.c:1976 sock_recvmsg_nosec net/socket.c:1078 [inline] sock_recvmsg+0x22c/0x270 net/socket.c:1100 __sys_recvfrom+0x240/0x3c0 net/socket.c:2256 __do_sys_recvfrom net/socket.c:2271 [inline] __se_sys_recvfrom net/socket.c:2267 [inline] __x64_sys_recvfrom+0xde/0x100 net/socket.c:2267 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd6f995b78e RSP: 002b:00007fd6fa83fe88 EFLAGS: 00000246 ORIG_RAX: 000000000000002d RAX: ffffffffffffffda RBX: 00007fd6fa8416c0 RCX: 00007fd6f995b78e RDX: 0000000000001000 RSI: 00007fd6fa840000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007fd6fa83ff58 R14: 00007fd6fa840000 R15: 0000000000000000 Showing all locks held in the system: 3 locks held by kworker/0:1/10: #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc900000f7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc900000f7bc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:956 1 lock held by khungtaskd/31: #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 5 locks held by kworker/1:1/39: #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc90000af7bc0 ((work_completion)(&rfkill->sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc90000af7bc0 ((work_completion)(&rfkill->sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8fcc2b28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_sync_work+0x2e/0x200 net/rfkill/core.c:1055 #3: ffff88805966cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x28/0xc0 net/bluetooth/hci_core.c:499 #4: ffff88805966c0c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5315 1 lock held by dhcpcd/5490: #0: ffffffff8f9ac0c8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f9ac0c8 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x32b/0x1b30 net/ipv4/devinet.c:1120 2 locks held by getty/5583: #0: ffff8880312aa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036c42f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:6/5910: #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc900048efbc0 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc900048efbc0 ((work_completion)(&rfkill_global_led_trigger_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8fcc2b28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_global_led_trigger_worker+0x27/0xd0 net/rfkill/core.c:182 3 locks held by kworker/0:6/5937: #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe55948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000496fbc0 ((work_completion)(&tn->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000496fbc0 ((work_completion)(&tn->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8f9ac0c8 (rtnl_mutex){+.+.}-{4:4}, at: tipc_net_finalize_work+0x1e/0x90 net/tipc/net.c:148 2 locks held by syz.0.3935/20365: #0: ffffffff8fa1a170 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e879368 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x16c0 fs/nfsd/nfsctl.c:1886 3 locks held by syz.2.4421/22159: #0: ffffffff8fa1a170 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffff88807db366f0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404 #2: ffffffff8e879368 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_rpc_status_get_dumpit+0xdc/0x1410 fs/nfsd/nfsctl.c:1483 1 lock held by syz.2.4421/22165: #0: ffff88807db366f0 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: netlink_dump+0xe4/0xe80 net/netlink/af_netlink.c:2267 2 locks held by syz.1.5277/25161: #0: ffffffff8fa1a170 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e879368 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x10a/0x5e0 fs/nfsd/nfsctl.c:2036 1 lock held by syz-executor/25581: #0: ffffffff8fcc2b28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 1 lock held by syz-executor/27206: #0: ffffffff8fcc2b28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 4 locks held by kworker/u8:26/27839: #0: ffff88801b2df148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88801b2df148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000bc87bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000bc87bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8f99d7d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xfe/0x7b0 net/core/net_namespace.c:670 #3: ffffffff8fcc2b28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 3 locks held by kworker/u8:27/27841: #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340 #1: ffffc9000bca7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc9000bca7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340 #2: ffffffff8f9ac0c8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 2 locks held by syz.6.6044/28048: #0: ffffffff8fa1a170 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e879368 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x17c/0xc40 fs/nfsd/nfsctl.c:1811 1 lock held by syz-executor/28717: #0: ffffffff8fcc2b28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 1 lock held by syz-executor/28719: #0: ffff88805966cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] #0: ffff88805966cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0 net/bluetooth/hci_core.c:2715 1 lock held by syz.5.6237/28809: #0: ffffffff8fcc2b28 (rfkill_global_mutex){+.+.}-{4:4}, at: rfkill_unregister+0xc8/0x220 net/rfkill/core.c:1145 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:161 [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:346 [inline] watchdog+0xf90/0xfe0 kernel/hung_task.c:515 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 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: 28829 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x82/0x90 kernel/kcov.c:316 Code: 8d 52 28 4d 39 ca 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 05 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 49 67 d5 09 cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 RSP: 0000:ffffc9000e0e7a58 EFLAGS: 00000293 RAX: ffffffff8212db07 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff888088749e80 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000e0e7c10 R08: ffff88803425f303 R09: 1ffff1100684be60 R10: dffffc0000000000 R11: ffffed100684be61 R12: ffffea0001ac04c0 R13: dffffc0000000000 R14: ffffc9000e0e7db0 R15: 1ffff92001c1cfb6 FS: 00007fcd6b153c80(0000) GS:ffff8881256f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcd6b4bd250 CR3: 0000000054968000 CR4: 00000000003526f0 Call Trace: rcu_read_unlock include/linux/rcupdate.h:895 [inline] pte_unmap include/linux/pgtable.h:136 [inline] wp_page_copy mm/memory.c:3823 [inline] do_wp_page+0x4217/0x5990 mm/memory.c:4183 handle_pte_fault mm/memory.c:6292 [inline] __handle_mm_fault mm/memory.c:6414 [inline] handle_mm_fault+0x1520/0x32a0 mm/memory.c:6583 do_user_addr_fault+0xa73/0x1360 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7fcd6b43f5c6 Code: b0 dc 07 00 48 8b 7d 70 48 85 ff 74 05 e8 49 ff ff ff 48 83 7b 28 00 74 0b e8 82 fe ff ff 48 8b 7d 70 eb e9 48 8b 03 48 89 df <48> 89 05 83 dc 07 00 e8 2e e3 fc ff 5a 5b 5d e9 25 fd ff ff 58 5b RSP: 002b:00007fff318be650 EFLAGS: 00010246 RAX: 00007fcd6b4bd3c8 RBX: 000055dc67173760 RCX: 000000055dc67178 RDX: 000055dc67171010 RSI: 0000000000000000 RDI: 000055dc67173760 RBP: 000055dc67173760 R08: 0000000000000410 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055dc67171910 R13: 000055dc67171c30 R14: 0000000000000000 R15: 00007fcd6b4bd460