INFO: task syz.3.1409:11478 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.1409      state:D stack:27224 pid:11478 tgid:11476 ppid:5632   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 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_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1948
 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:2556
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
 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+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f581659ce59
RSP: 002b:00007f58173a9028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f5816815fa0 RCX: 00007f581659ce59
RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000000000000006
RBP: 00007f5816632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5816816038 R14: 00007f5816815fa0 R15: 00007ffc3dca5e68
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:2/36:
 #0: ffff8880b863aee0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:652
 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
 #2: ffff8880371aa1d8 (&hard_iface->bat_iv.ogm_buff_mutex){+.+.}-{4:4}, at: batadv_iv_ogm_schedule+0xe8/0xf80 net/batman-adv/bat_iv_ogm.c:908
 #3: ffff8880b8626118 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x8ee/0xf30 kernel/time/timer.c:1117
2 locks held by getty/5384:
 #0: ffff888036f8d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
2 locks held by syz.2.1207/10683:
 #0: ffffffff8fe393a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff8ec8b1c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_threads_set_doit+0x2b9/0xc20 fs/nfsd/nfsctl.c:1644
2 locks held by syz.3.1409/11478:
 #0: ffffffff8fe393a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff8ec8b1c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1948
2 locks held by syz.4.1697/12582:
 #0: ffffffff8fe393a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff8ec8b1c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x1670 fs/nfsd/nfsctl.c:1948
2 locks held by syz.6.1823/13036:
 #0: ffffffff8fe393a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
 #1: ffffffff8ec8b1c0 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x181/0xcd0 fs/nfsd/nfsctl.c:1873
2 locks held by syz.5.1981/13695:
 #0: ffffffff8fdba228 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8e962e78 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz.1.2004/13778:
 #0: ffff8880559e1f00 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff8880559e1f00 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:721 [inline]
 #0: ffff8880559e1f00 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1514
4 locks held by syz.8.2007/13784:
 #0: ffff888039afb600 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
 #0: ffff888039afb600 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:721 [inline]
 #0: ffff888039afb600 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1514
 #1: ffffffff8fe37408 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x54/0x90 kernel/notifier.c:379
 #2: ffff88805577d0d0 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nft_rcv_nl_event+0x13d/0xe00 net/netfilter/nf_tables_api.c:12068
 #3: ffffffff8e962fa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #3: ffffffff8e962fa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz.0.2006/13787:
2 locks held by syz.7.2008/13788:
 #0: ffffffff8fdc8f40 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:641 [inline]
 #0: ffffffff8fdc8f40 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3505
 #1: ffffffff8e962fa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
 #1: ffffffff8e962fa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961

=============================================

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 05/09/2026
Call Trace:
 <TASK>
 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+0x389/0x470 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 13785 Comm: syz.8.2007 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__read_once_word_nocheck+0x3/0x10 include/asm-generic/rwonce.h:67
Code: 00 48 ba 00 00 00 00 00 fc ff df e9 88 fc ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 07 <e9> 08 27 35 0a cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000517f290 EFLAGS: 00000202
RAX: ffffffff821b09d2 RBX: ffffc9000517f7d8 RCX: 1ffff92000a2fe01
RDX: ffffffff90d220de RSI: 0000000000000002 RDI: ffffc9000517f7d8
RBP: 1ffff92000a2fe6e R08: 0000000000000001 R09: ffffffff8e95cca0
R10: ffffc9000517f3b8 R11: ffffffff81b0e0e0 R12: ffffc90005180000
R13: 1ffff92000a2fe6f R14: ffffc9000517f368 R15: ffffc90005178000
FS:  0000000000000000(0000) GS:ffff88812528a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1ab1bea2f8 CR3: 000000004ea98000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 deref_stack_reg arch/x86/kernel/unwind_orc.c:422 [inline]
 unwind_next_frame+0xed7/0x2550 arch/x86/kernel/unwind_orc.c:614
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x31c/0x660 mm/slub.c:5420
 kmalloc_noprof include/linux/slab.h:950 [inline]
 slab_free_hook mm/slub.c:2641 [inline]
 slab_free mm/slub.c:6251 [inline]
 kmem_cache_free+0x156/0x650 mm/slub.c:6378
 tear_down_vmas+0x312/0x520 mm/mmap.c:1262
 exit_mmap+0x4b6/0x9e0 mm/mmap.c:1320
 __mmput+0x118/0x430 kernel/fork.c:1178
 exit_mm+0x1f6/0x2d0 kernel/exit.c:582
 do_exit+0x6a2/0x22c0 kernel/exit.c:964
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1119
 get_signal+0x1284/0x1330 kernel/signal.c:3037
 arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0xa9/0x680 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f449d99ce59
Code: Unable to access opcode bytes at 0x7f449d99ce2f.
RSP: 002b:00007f449e7e70e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f449dc15fa8 RCX: 00007f449d99ce59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f449dc15fa8
RBP: 00007f449dc15fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f449dc16038 R14: 00007ffcb4f5d340 R15: 00007ffcb4f5d428
 </TASK>