INFO: task syz.2.3894:20660 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3894 state:D stack:25208 pid:20660 tgid:20659 ppid:17952 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x17b4/0x5680 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
__mutex_lock_common kernel/locking/mutex.c:726 [inline]
__mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820
nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1728
genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
__sys_sendmsg net/socket.c:2784 [inline]
__do_sys_sendmsg net/socket.c:2789 [inline]
__se_sys_sendmsg net/socket.c:2787 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9c1e59cdd9
RSP: 002b:00007f9c1f40f028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f9c1e815fa0 RCX: 00007f9c1e59cdd9
RDX: 0000000020000000 RSI: 0000200000000140 RDI: 0000000000000008
RBP: 00007f9c1e632d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9c1e816038 R14: 00007f9c1e815fa0 R15: 00007ffc1a71bb28
Showing all locks held in the system:
1 lock held by khungtaskd/30:
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5382:
#0: ffff8880361fe0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
5 locks held by kworker/u9:6/5640:
2 locks held by syz.1.2161/13844:
#0: ffffffff8fe3f0e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1938
1 lock held by udevd/19141:
#0: ffff8880274d0350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:953
2 locks held by syz.2.3894/20660:
#0: ffffffff8fe3f0e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_get_doit+0x1c0/0x790 fs/nfsd/nfsctl.c:1728
2 locks held by syz.3.4316/22190:
#0: ffffffff8fe3f0e8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8ec8aca0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1938
2 locks held by syz-executor/27313:
#0: ffffffff8fdc0c28 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8fdcf900 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d7/0x840 net/ipv4/ip_tunnel.c:1146
1 lock held by syz.6.5696/27435:
#0: ffffffff8fdcf900 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fdcf900 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3438
2 locks held by syz.5.5701/27458:
#0: ffffffff8fdcf900 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fdcf900 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3438
#1: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#1: ffffffff8e963068 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz.7.5705/27490:
#0: ffffffff8fdcf900 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bc/0x1e10 drivers/net/tun.c:3080
1 lock held by syz.7.5705/27492:
#0: ffffffff8fdcf900 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bc/0x1e10 drivers/net/tun.c:3080
1 lock held by syz.7.5705/27494:
#0: ffffffff8fdcf900 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8fdcf900 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x722/0xbe0 net/core/rtnetlink.c:7002
1 lock held by syz.7.5705/27496:
=============================================
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 04/18/2026
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: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+0xfd3/0x1030 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: 14712 Comm: kworker/u8:17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:__rcu_read_unlock+0xa/0xe0 kernel/rcu/tree_plugin.h:431
Code: dc 48 89 df e8 07 6e 85 00 eb d2 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 41 55 <41> 54 53 49 bf 00 00 00 00 00 fc ff df 65 48 8b 3d 29 83 8d 11 48
RSP: 0018:ffffc9001b737740 EFLAGS: 00000286
RAX: ba94c6a409639a00 RBX: 0000000000000001 RCX: 0000000000000046
RDX: 0000000000000005 RSI: ffffffff8e219b9d RDI: ffffffff8c28ade0
RBP: ffffc9001b737870 R08: ffff88813fe78603 R09: 1ffff11027fcf0c0
R10: dffffc0000000000 R11: ffffed1027fcf0c1 R12: dffffc0000000000
R13: ffff88813fe79558 R14: 0000000000000200 R15: ffffffff8225964e
FS: 0000000000000000(0000) GS:ffff88812538f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f08a7dea4c0 CR3: 000000000e74a000 CR4: 00000000003526f0
Call Trace:
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
pte_unmap include/linux/pgtable.h:117 [inline]
__text_poke+0x84b/0x9a0 arch/x86/kernel/alternative.c:2648
text_poke arch/x86/kernel/alternative.c:2672 [inline]
smp_text_poke_batch_finish+0xd36/0x1160 arch/x86/kernel/alternative.c:3061
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:906
process_one_work kernel/workqueue.c:3302 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3385
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3466
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