INFO: task syz.3.3736:21053 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.3736      state:D stack:25896 pid:21053 tgid:21038 ppid:13085  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 genl_rcv_msg+0x10d/0x790
 netlink_rcv_skb+0x208/0x470
 genl_rcv+0x28/0x40
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 __sys_sendto+0x3bd/0x520
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f619d190a7c
RSP: 002b:00007f619df27ec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f619df27fc0 RCX: 00007f619d190a7c
RDX: 0000000000000020 RSI: 00007f619df28010 RDI: 0000000000000011
RBP: 0000000000000000 R08: 00007f619df27f14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000011
R13: 00007f619df27f68 R14: 00007f619df28010 R15: 0000000000000000
 </TASK>
INFO: task syz.2.3739:21049 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3739      state:D stack:25896 pid:21049 tgid:21048 ppid:5850   task_flags:0x480140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 blk_mq_freeze_queue_wait+0xf4/0x170
 queue_limits_commit_update_frozen+0x5d/0x3e0
 nbd_set_size+0x47e/0x6a0
 nbd_genl_size_set+0x2eb/0x3c0
 nbd_genl_reconfigure+0x409/0x1870
 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: 0033:0x7f7b7618ebe9
RSP: 002b:00007f7b76f4c038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f7b763c5fa0 RCX: 00007f7b7618ebe9
RDX: 0000000020000800 RSI: 0000200000000200 RDI: 0000000000000010
RBP: 00007f7b76211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7b763c6038 R14: 00007f7b763c5fa0 R15: 00007ffe333a0468
 </TASK>
INFO: task syz.2.3739:21050 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3739      state:D stack:27752 pid:21050 tgid:21048 ppid:5850   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 genl_rcv_msg+0x10d/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: 0033:0x7f7b7618ebe9
RSP: 002b:00007f7b76f2b038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f7b763c6090 RCX: 00007f7b7618ebe9
RDX: 0000000020000800 RSI: 0000200000000200 RDI: 0000000000000010
RBP: 00007f7b76211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7b763c6128 R14: 00007f7b763c6090 R15: 00007ffe333a0468
 </TASK>
INFO: task syz.4.3740:21058 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.3740      state:D stack:27880 pid:21058 tgid:21057 ppid:13128  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 genl_rcv_msg+0x10d/0x790
 netlink_rcv_skb+0x208/0x470
 genl_rcv+0x28/0x40
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 __sys_sendto+0x3bd/0x520
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe96a990a7c
RSP: 002b:00007fe96b834ec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fe96b834fc0 RCX: 00007fe96a990a7c
RDX: 0000000000000020 RSI: 00007fe96b835010 RDI: 0000000000000005
RBP: 0000000000000000 R08: 00007fe96b834f14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005
R13: 00007fe96b834f68 R14: 00007fe96b835010 R15: 0000000000000000
 </TASK>
INFO: task syz.4.3740:21059 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.3740      state:D stack:27016 pid:21059 tgid:21057 ppid:13128  task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e6/0x1350
 genl_rcv_msg+0x10d/0x790
 netlink_rcv_skb+0x208/0x470
 genl_rcv+0x28/0x40
 netlink_unicast+0x82f/0x9e0
 netlink_sendmsg+0x805/0xb30
 __sock_sendmsg+0x21c/0x270
 __sys_sendto+0x3bd/0x520
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe96a990a7c
RSP: 002b:00007fe96b813ec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fe96b813fc0 RCX: 00007fe96a990a7c
RDX: 0000000000000020 RSI: 00007fe96b814010 RDI: 0000000000000008
RBP: 0000000000000000 R08: 00007fe96b813f14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000008
R13: 00007fe96b813f68 R14: 00007fe96b814010 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by kworker/u8:1/13:
 #0: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
1 lock held by khungtaskd/34:
 #0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5671:
 #0: ffff88810c8400a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029032f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
1 lock held by udevd/5855:
 #0: ffff888022e7e358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
2 locks held by syz.3.3736/21053:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
6 locks held by syz.2.3739/21049:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
 #2: ffff88801af08a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_genl_reconfigure+0x36f/0x1870
 #3: ffff888106e15f58 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x292/0x6a0
 #4: ffff888106e158f8 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x5d/0x3e0
 #5: ffff888106e15930 (&q->q_usage_counter(queue)#33){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x5d/0x3e0
2 locks held by syz.2.3739/21050:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz.4.3740/21058:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz.4.3740/21059:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/21068:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/21070:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/21075:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/21099:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/21101:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/21102:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/21126:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/21136:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/21139:
 #0: ffffffff8f59ea90 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e8a8 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 34 Comm: khungtaskd Not tainted syzkaller #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+0xf93/0xfe0
 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: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__lock_acquire+0x50c/0xd20
Code: 49 83 c7 28 41 89 c4 48 39 cb 0f 8d d6 00 00 00 48 83 fb 31 0f 83 92 00 00 00 41 8b 07 25 ff 1f 00 00 48 0f a3 05 64 1d 0b 12 <73> 10 48 69 c0 c8 00 00 00 48 8d 88 10 83 49 93 eb 40 83 3d cb ac
RSP: 0018:ffffc900001078f0 EFLAGS: 00000003
RAX: 0000000000000785 RBX: 0000000000000001 RCX: 0000000000000002
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff88801c2f8000
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b4808d2
R10: dffffc0000000000 R11: ffffffff8b480800 R12: 00000000ffffff05
R13: 0000000000000001 R14: ffff88801c2f8b40 R15: ffff88801c2f8b38
FS:  0000000000000000(0000) GS:ffff8880b8614000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffff0000 CR3: 000000000df36000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x120/0x360
 batadv_nc_worker+0xef/0x610
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
