INFO: task syz.0.1069:8320 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc7-syzkaller-01630-g8b5a19b4ff6a-dirty #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.1069      state:D stack:24952 pid:8320  tgid:8319  ppid:5827   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x16fd/0x4cf0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x724/0xe80
 nfsd_nl_listener_get_doit+0x10a/0x5e0
 genl_family_rcv_msg_doit+0x215/0x300
 genl_rcv_msg+0x60e/0x790
 netlink_rcv_skb+0x208/0x470
 genl_rcv+0x28/0x40
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 ____sys_sendmsg+0x505/0x830
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1871f8e9a9
RSP: 002b:00007f1872daa038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f18721b5fa0 RCX: 00007f1871f8e9a9
RDX: 0000000000000010 RSI: 0000200000001540 RDI: 0000000000000003
RBP: 00007f1872010d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f18721b5fa0 R15: 00007ffcb9a1d9b8
 </TASK>

Showing all locks held in the system:
2 locks held by ksoftirqd/0/15:
 #0: ffff88804b039f58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff88804b023f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39a/0x6d0
1 lock held by khungtaskd/34:
 #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5658:
 #0: ffff88810e4910a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
3 locks held by kworker/1:5/5890:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc9000449fbc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
2 locks held by syz.2.1045/8269:
 #0: ffffffff8f584570 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e41bd68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690
2 locks held by syz.0.1069/8320:
 #0: ffffffff8f584570 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e41bd68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_get_doit+0x10a/0x5e0
2 locks held by syz.4.1848/10083:
 #0: ffffffff8f584570 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e41bd68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690
2 locks held by syz.5.3135/13057:
 #0: ffffffff8f584570 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e41bd68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690
2 locks held by syz.1.4964/17117:
 #0: ffffffff8f584570 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8e41bd68 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1690
1 lock held by syz.3.5499/18308:
1 lock held by syz.6.5511/18337:
1 lock held by syz.7.5512/18334:
 #0: ffffffff8e144bf8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-01630-g8b5a19b4ff6a-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xfee/0x1030
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18334 Comm: syz.7.5512 Not tainted 6.16.0-rc7-syzkaller-01630-g8b5a19b4ff6a-dirty #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:debug_check_no_obj_freed+0x212/0x470
Code: c0 0f 84 45 02 00 00 4d 89 fe 49 c1 ee 03 48 b8 00 00 00 00 00 fc ff df 41 80 3c 06 00 74 08 4c 89 ff e8 41 90 5b fd 49 8b 07 <48> 89 44 24 18 4d 8d 67 18 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00
RSP: 0018:ffffc90002bdf800 EFLAGS: 00000046
RAX: ffff88801a455508 RBX: 0000000000000002 RCX: dffffc0000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90002bdf6e0
RBP: ffff888136636dd0 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200057bedc R12: ffff8881067da670
R13: ffff888028fbc000 R14: 1ffff11020cfb4d2 R15: ffff8881067da690
FS:  0000555557527500(0000) GS:ffff8880b8626000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f91c7a34d58 CR3: 0000000026324000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __free_frozen_pages+0x509/0xe70
 vfree+0x25a/0x400
 kcov_close+0x28/0x50
 __fput+0x44c/0xa70
 task_work_run+0x1d4/0x260
 do_exit+0x6b5/0x22e0
 do_group_exit+0x21c/0x2d0
 get_signal+0x1286/0x1340
 arch_do_signal_or_restart+0x9a/0x750
 exit_to_user_mode_loop+0x75/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd74db8e9a9
Code: Unable to access opcode bytes at 0x7fd74db8e97f.
RSP: 002b:00007ffff794bb28 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000036e97 RCX: 00007fd74db8e9a9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fd74ddb7ba0 R08: 0000000000000001 R09: 0000001df794be1f
R10: 00007fd74da00000 R11: 0000000000000246 R12: 00007fd74ddb5fac
R13: 00007fd74ddb5fa0 R14: ffffffffffffffff R15: 00007ffff794bc40
 </TASK>
