INFO: task syz.0.2575:14924 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2575      state:D stack:25696 pid:14924 tgid:14923 ppid:5846   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: 0033:0x7fd91d78eba9
RSP: 002b:00007fd91e5e3038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd91d9d5fa0 RCX: 00007fd91d78eba9
RDX: 0000000020000800 RSI: 0000200000000200 RDI: 000000000000000e
RBP: 00007fd91d811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd91d9d6038 R14: 00007fd91d9d5fa0 R15: 00007ffc325fcca8
 </TASK>
INFO: task syz.0.2575:14925 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2575      state:D stack:26088 pid:14925 tgid:14923 ppid:5846   task_flags:0x400040 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: 0033:0x7fd91d790a3c
RSP: 002b:00007fd91e5c0ec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fd91e5c0fc0 RCX: 00007fd91d790a3c
RDX: 0000000000000020 RSI: 00007fd91e5c1010 RDI: 000000000000000a
RBP: 0000000000000000 R08: 00007fd91e5c0f14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000000a
R13: 00007fd91e5c0f68 R14: 00007fd91e5c1010 R15: 0000000000000000
 </TASK>
INFO: task syz.4.2577:14934 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2577      state:D stack:28616 pid:14934 tgid:14933 ppid:11304  task_flags:0x400040 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: 0033:0x7f4d30390a3c
RSP: 002b:00007f4d312aaec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f4d312aafc0 RCX: 00007f4d30390a3c
RDX: 0000000000000020 RSI: 00007f4d312ab010 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007f4d312aaf14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 00007f4d312aaf68 R14: 00007f4d312ab010 R15: 0000000000000000
 </TASK>
INFO: task syz.4.2577:14936 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2577      state:D stack:28616 pid:14936 tgid:14933 ppid:11304  task_flags:0x400040 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: 0033:0x7f4d30390a3c
RSP: 002b:00007f4d31289ec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f4d31289fc0 RCX: 00007f4d30390a3c
RDX: 0000000000000020 RSI: 00007f4d3128a010 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007f4d31289f14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004
R13: 00007f4d31289f68 R14: 00007f4d3128a010 R15: 0000000000000000
 </TASK>
INFO: task syz.4.2577:14940 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2577      state:D stack:25896 pid:14940 tgid:14933 ppid:11304  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: 0033:0x7f4d30390a3c
RSP: 002b:00007f4d31268ec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f4d31268fc0 RCX: 00007f4d30390a3c
RDX: 0000000000000020 RSI: 00007f4d31269010 RDI: 000000000000000b
RBP: 0000000000000000 R08: 00007f4d31268f14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000000b
R13: 00007f4d31268f68 R14: 00007f4d31269010 R15: 0000000000000000
 </TASK>
INFO: task syz.3.2579:14939 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.2579      state:D stack:27880 pid:14939 tgid:14938 ppid:11302  task_flags:0x400040 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: 0033:0x7fa573790a3c
RSP: 002b:00007fa5745a7ec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fa5745a7fc0 RCX: 00007fa573790a3c
RDX: 0000000000000020 RSI: 00007fa5745a8010 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007fa5745a7f14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004
R13: 00007fa5745a7f68 R14: 00007fa5745a8010 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/u8:0/12:
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/5676:
 #0: ffff8880234d50a0 (&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
1 lock held by udevd/5843:
 #0: ffff88802173d358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by udevd/6147:
 #0: ffff8880216bd358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
3 locks held by kworker/u8:6/9578:
6 locks held by syz.0.2575/14924:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
 #2: ffff8880216e8a30 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_genl_reconfigure+0x36f/0x1870
 #3: ffff88802149df58 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x292/0x6a0
 #4: ffff88802149d8f8 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x5d/0x3e0
 #5: ffff88802149d930 (&q->q_usage_counter(queue)#33){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x5d/0x3e0
2 locks held by syz.0.2575/14925:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz.4.2577/14934:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz.4.2577/14936:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz.4.2577/14940:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz.3.2579/14939:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/14947:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/14949:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/14953:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/14974:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/14976:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/14978:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/15001:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/15003:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/15005:
 #0: ffffffff8f59e930 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59e748 (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: 12 Comm: kworker/u8:0 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+0x4d5/0xd20
Code: 00 00 00 0f 84 d7 04 00 00 44 3b bf e8 0a 00 00 0f 8d 04 01 00 00 49 63 df 48 8d 04 9b 4c 8d 3c c7 49 81 c7 10 0b 00 00 eb 1d <44> 89 e0 48 ff c3 48 63 8f e8 0a 00 00 49 83 c7 28 41 89 c4 48 39
RSP: 0018:ffffc900000f78f0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff934f1fd8
RDX: 0000000000000003 RSI: 0000000000000000 RDI: ffff88801c2f5640
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8b479342
R10: dffffc0000000000 R11: ffffffff8b479270 R12: 00000000ffffff05
R13: 0000000000000001 R14: ffff88801c2f6180 R15: ffff88801c2f6178
FS:  0000000000000000(0000) GS:ffff8880b8618000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b3948a52a8 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>
