INFO: task syz.4.2216:13859 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2216 state:D stack:27080 pid:13859 tgid:13857 ppid:5824 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x1585/0x5340 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1683
genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x61c/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+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe1a499c629
RSP: 002b:00007fe1a5835028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fe1a4c15fa0 RCX: 00007fe1a499c629
RDX: 0000000024048000 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007fe1a4a32b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe1a4c16038 R14: 00007fe1a4c15fa0 R15: 00007fffca9c8858
Showing all locks held in the system:
5 locks held by ksoftirqd/1/23:
1 lock held by khungtaskd/30:
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by udevd/5191:
2 locks held by getty/5583:
#0: ffff8880372710a0 (&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+0x45c/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by kworker/u9:2/5829:
#0: ffff888026bb0148 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff888026bb0148 ((wq_completion)nbd1-recv){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc90003ff7c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90003ff7c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
2 locks held by kworker/0:4/5894:
#0: ffff88813fe0f548 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
#0: ffff88813fe0f548 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
#1: ffffc90004847c40 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#1: ffffc90004847c40 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
2 locks held by syz.3.793/8837:
#0: ffffffff8fc39470 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea86928 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x16c0 fs/nfsd/nfsctl.c:1893
2 locks held by syz.4.2216/13859:
#0: ffffffff8fc39470 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8ea86928 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1683
1 lock held by syz-executor/14819:
#0: ffffffff8fbcb808 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fbcb808 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
1 lock held by syz-executor/15801:
#0: ffffffff8fbcb808 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fbcb808 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
2 locks held by syz-executor/16483:
#0: ffffffff8fbcb808 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fbcb808 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
#1: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz-executor/17098:
#0: ffffffff8fbcb808 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fbcb808 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
5 locks held by syz-executor/20612:
#0: ffff888070170ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:500 [inline]
#0: ffff888070170ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5a0 net/bluetooth/hci_core.c:2716
#1: ffff8880701700c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x10e0 net/bluetooth/hci_sync.c:5346
#2: ffffffff8fd57ea8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2151 [inline]
#2: ffffffff8fd57ea8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2644
#3: ffff88802a9bfaf8 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5c0 net/bluetooth/l2cap_core.c:1755
#4: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#4: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 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: 1320 Comm: kworker/u8:8 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:check_preemption_disabled+0x1d/0xe0 lib/smp_processor_id.c:53
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 65 8b 05 57 73 6e 07 65 8b 0d 4c 73 6e 07 f7 c1 ff ff ff 7f 74 0c 5b <41> 5e 41 5f 5d c3 cc cc cc cc cc 9c 59 f7 c1 00 02 00 00 74 ea 65
RSP: 0018:ffffc90000a08678 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000202 RCX: 0000000080000302
RDX: 0000000000000100 RSI: ffffffff8df0b19b RDI: ffffffff8c27a480
RBP: ffffc90000a089b0 R08: ffff888079ec9303 R09: 1ffff1100f3d9260
R10: dffffc0000000000 R11: ffffed100f3d9261 R12: 1ffff92000141100
R13: ffffffff897bcea4 R14: ffffffff8e760340 R15: ffff8880293d3c80
FS: 0000000000000000(0000) GS:ffff888125566000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff82243f60 CR3: 000000003530e000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline]
lock_release+0xa1/0x3d0 kernel/locking/lockdep.c:5888
rcu_lock_release include/linux/rcupdate.h:322 [inline]
rcu_read_unlock_bh include/linux/rcupdate.h:921 [inline]
__dev_queue_xmit+0x1e5f/0x38a0 net/core/dev.c:4863
dev_queue_xmit include/linux/netdevice.h:3384 [inline]
can_send+0x921/0xd20 net/can/af_can.c:279
can_can_gw_rcv+0xcb0/0xf70 net/can/gw.c:569
deliver net/can/af_can.c:575 [inline]
can_rcv_filter+0x126/0x7d0 net/can/af_can.c:602
can_receive+0x2c6/0x440 net/can/af_can.c:674
can_rcv+0x1f9/0x330 net/can/af_can.c:699
__netif_receive_skb_one_core net/core/dev.c:6156 [inline]
__netif_receive_skb net/core/dev.c:6269 [inline]
process_backlog+0xc66/0x1950 net/core/dev.c:6621
__napi_poll+0xae/0x340 net/core/dev.c:7685
napi_poll net/core/dev.c:7748 [inline]
net_rx_action+0x627/0xf70 net/core/dev.c:7900
handle_softirqs+0x22a/0x870 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:395 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:891 [inline]
nsim_dev_trap_report_work+0x7c7/0xb80 drivers/net/netdevsim/dev.c:922
process_one_work kernel/workqueue.c:3275 [inline]
process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245