INFO: task syz.1.87:6230 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.87        state:D stack:25800 pid:6230  tgid:6227  ppid:5843   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: 0033:0x7ff95678eba9
RSP: 002b:00007ff9576a3038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff9569d5fa0 RCX: 00007ff95678eba9
RDX: 0000000020000800 RSI: 0000200000000200 RDI: 000000000000000a
RBP: 00007ff956811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff9569d6038 R14: 00007ff9569d5fa0 R15: 00007fff9ca71548
 </TASK>
INFO: task syz.1.87:6234 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.87        state:D stack:20968 pid:6234  tgid:6227  ppid:5843   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: 0033:0x7ff95678eba9
RSP: 002b:00007ff957682038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff9569d6090 RCX: 00007ff95678eba9
RDX: 0000000020000800 RSI: 0000200000000200 RDI: 000000000000000a
RBP: 00007ff956811e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff9569d6128 R14: 00007ff9569d6090 R15: 00007fff9ca71548
 </TASK>
INFO: task syz.1.87:6241 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.87        state:D stack:26568 pid:6241  tgid:6227  ppid:5843   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: 0033:0x7ff956790a3c
RSP: 002b:00007ff95765fec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007ff95765ffc0 RCX: 00007ff956790a3c
RDX: 0000000000000028 RSI: 00007ff957660010 RDI: 0000000000000006
RBP: 0000000000000000 R08: 00007ff95765ff14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000006
R13: 00007ff95765ff68 R14: 00007ff957660010 R15: 0000000000000000
 </TASK>
INFO: task syz.0.91:6249 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.91        state:D stack:28328 pid:6249  tgid:6247  ppid:5839   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: 0033:0x7fbfe4d90a3c
RSP: 002b:00007fbfe5b2dec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fbfe5b2dfc0 RCX: 00007fbfe4d90a3c
RDX: 0000000000000028 RSI: 00007fbfe5b2e010 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007fbfe5b2df14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004
R13: 00007fbfe5b2df68 R14: 00007fbfe5b2e010 R15: 0000000000000000
 </TASK>
INFO: task syz.2.93:6255 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.93        state:D stack:28328 pid:6255  tgid:6254  ppid:5844   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: 0033:0x7fc0e0f90a3c
RSP: 002b:00007fc0e1e5aec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007fc0e1e5afc0 RCX: 00007fc0e0f90a3c
RDX: 0000000000000028 RSI: 00007fc0e1e5b010 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007fc0e1e5af14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004
R13: 00007fc0e1e5af68 R14: 00007fc0e1e5b010 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
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/5670:
 #0: ffff888025b310a0 (&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/5840:
 #0: ffff88810a080358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
2 locks held by kworker/u8:4/5871:
 #0: ffff88804b039f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140
 #1: ffff88804b024008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880
6 locks held by syz.1.87/6230:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
 #2: ffff88810a040230 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_genl_reconfigure+0x36f/0x1870
 #3: ffff888109f65f58 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x292/0x6a0
 #4: ffff888109f658f8 (&q->q_usage_counter(io)#49){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x5d/0x3e0
 #5: ffff888109f65930 (&q->q_usage_counter(queue)#33){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x5d/0x3e0
2 locks held by syz.1.87/6234:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz.1.87/6241:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz.0.91/6249:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz.2.93/6255:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/6262:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/6272:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/6274:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/6295:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/6305:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/6307:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/6322:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/6332:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/6334:
 #0: ffffffff8f59ed50 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f59eb68 (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: 5871 Comm: kworker/u8:4 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:  0x0 (bat_events)
RIP: 0010:__list_del_entry_valid_or_report+0x0/0x190
Code: 8b 48 89 de 4c 89 f1 e8 ae 52 57 fc 90 0f 0b 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 41 57 41 56 41 55 41 54 53 48 89 fb 49 bd 00 00 00 00
RSP: 0018:ffffc9000334f900 EFLAGS: 00000046
RAX: 1ffff110252692fd RBX: ffff88801a4a0050 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffffffff8be33860 RDI: ffff8881293497e8
RBP: ffff8881293497e8 R08: ffffffff8fa38f37 R09: 1ffffffff1f471e6
R10: dffffc0000000000 R11: fffffbfff1f471e7 R12: ffff8880294f97e8
R13: ffff8881293497e0 R14: dffffc0000000000 R15: ffff88801a4a0068
FS:  0000000000000000(0000) GS:ffff8880b8614000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558e02899e68 CR3: 0000000028420000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __pwq_activate_work+0x181/0x340
 pwq_dec_nr_in_flight+0x750/0xf30
 process_scheduled_works+0x100d/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
