INFO: task syz.6.17263:14672 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.17263     state:D stack:26672 pid:14672 tgid:14671 ppid:11589  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7383
 __mutex_lock_common kernel/locking/mutex.c:726 [inline]
 __mutex_lock+0x7bf/0x1550 kernel/locking/mutex.c:821
 nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1814
 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
 genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x7bb/0x940 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_sendmsg+0x54e/0x850 net/socket.c:2684
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738
 __sys_sendmsg net/socket.c:2770 [inline]
 __do_sys_sendmsg net/socket.c:2775 [inline]
 __se_sys_sendmsg net/socket.c:2773 [inline]
 __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2773
 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: 0033:0x7fc5a1b9de99
RSP: 002b:00007fc5a2ad7028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc5a1e25fa0 RCX: 00007fc5a1b9de99
RDX: 0000000004008090 RSI: 0000200000000140 RDI: 0000000000000007
RBP: 00007fc5a1c33eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc5a1e26038 R14: 00007fc5a1e25fa0 R15: 00007ffcc200be58
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by klogd/4985:
 #0: ffff8880b873b160 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:667
2 locks held by getty/5385:
 #0: ffff8880365ff0a0 (&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+0x45a/0x1360 drivers/tty/n_tty.c:2211
2 locks held by syz-executor/5750:
2 locks held by syz.3.16108/10630:
 #0: ffffffff9009c8a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff8ee8e620 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x135/0x1750 fs/nfsd/nfsctl.c:1964
2 locks held by syz.6.17263/14672:
 #0: ffffffff9009c8a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff8ee8e620 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_set_doit+0xcd/0x7a0 fs/nfsd/nfsctl.c:1814
1 lock held by udevd/15002:
 #0: ffff88802230a350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:948
1 lock held by udevd/15364:
 #0: ffff8880227ce350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:948
2 locks held by syz.5.17661/15949:
 #0: ffffffff9009c8a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff8ee8e620 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x104/0x610 fs/nfsd/nfsctl.c:2114
1 lock held by udevd/16814:
 #0: ffff888020f52350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:948
4 locks held by syz.7.18663/19071:
 #0: ffff888076ef52c0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #0: ffff888076ef52c0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:709 [inline]
 #0: ffff888076ef52c0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x82/0x220 net/socket.c:1501
 #1: ffffffff9009a8c8 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:379
 #2: ffff8880367574d0 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nft_rcv_nl_event+0x148/0xe60 net/netfilter/nf_tables_api.c:12089
 #3: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
 #3: ffffffff8eb5ff68 (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: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
Call Trace:
 <TASK>
 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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64
Code: 5c 80 02 e9 13 05 03 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 53 3a 1a 00 fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc90000197e40 EFLAGS: 00000242
RAX: 00000000010e3a37 RBX: ffffffff819ab450 RCX: 0000000080000001
RDX: 0000000000000001 RSI: ffffffff8e22a902 RDI: ffffffff8c4bd380
RBP: ffffc90000197f10 R08: ffff8880b87338db R09: 1ffff110170e671b
R10: dffffc0000000000 R11: ffffed10170e671c R12: 0000000000000000
R13: 1ffff11003bdf000 R14: 1ffff92000032fd0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125057000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f646a3ef4b8 CR3: 000000007ac72000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/kernel/process.c:767 [inline]
 default_idle+0x9/0x20 arch/x86/kernel/process.c:768
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:199 [inline]
 do_idle+0x2e0/0x540 kernel/sched/idle.c:355
 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:454
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312
 common_startup_64+0x13e/0x157
 </TASK>