INFO: task syz.0.9082:26880 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.9082      state:D stack:25848 pid:26880 tgid:26879 ppid:5880   task_flags:0x480140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14bc/0x5000
 schedule+0x165/0x360
 blk_mq_freeze_queue_wait+0xf1/0x170
 queue_limits_commit_update_frozen+0x56/0xd0
 nbd_set_size+0x47e/0x6a0
 nbd_genl_size_set+0x2eb/0x3c0
 nbd_genl_reconfigure+0x414/0x1a50
 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+0x505/0x820
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3c5b78f7c9
RSP: 002b:00007f3c5c65e038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3c5b9e5fa0 RCX: 00007f3c5b78f7c9
RDX: 0000000000004000 RSI: 0000200000000200 RDI: 0000000000000004
RBP: 00007f3c5b7f297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3c5b9e6038 R14: 00007f3c5b9e5fa0 R15: 00007fff6d0b3bd8
 </TASK>
INFO: task syz.1.9084:26882 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.9084      state:D stack:27808 pid:26882 tgid:26881 ppid:5885   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14bc/0x5000
 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/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4eff79165c
RSP: 002b:00007f4f005a1ec0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f4f005a1fc0 RCX: 00007f4eff79165c
RDX: 0000000000000020 RSI: 00007f4f005a2010 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007f4f005a1f14 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000004
R13: 00007f4f005a1f68 R14: 00007f4f005a2010 R15: 0000000000000000
 </TASK>
INFO: task syz.2.9110:26939 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.9110      state:D stack:27856 pid:26939 tgid:26938 ppid:5888   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x14bc/0x5000
 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+0x505/0x820
 ___sys_sendmsg+0x21f/0x2a0
 __x64_sys_sendmsg+0x19b/0x260
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fac9598f7c9
RSP: 002b:00007fac96794038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fac95be5fa0 RCX: 00007fac9598f7c9
RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000000000000003
RBP: 00007fac959f297f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fac95be6038 R14: 00007fac95be5fa0 R15: 00007fff77d51d38
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5654:
 #0: ffff8881741af0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc9000356b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460
1 lock held by udevd/25026:
 #0: ffff888111779358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
6 locks held by syz.0.9082/26880:
 #0: ffffffff8f3774f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f377308 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
 #2: ffff888120a32a78 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_genl_reconfigure+0x375/0x1a50
 #3: ffff88816cf83ff0 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x292/0x6a0
 #4: ffff88816cf83990 (&q->q_usage_counter(io)#70){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x56/0xd0
 #5: ffff88816cf839c8 (&q->q_usage_counter(queue)#53){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x56/0xd0
2 locks held by syz.1.9084/26882:
 #0: ffffffff8f3774f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f377308 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz.2.9110/26939:
 #0: ffffffff8f3774f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f377308 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/26943:
 #0: ffffffff8f3774f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f377308 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/26944:
 #0: ffffffff8f3774f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f377308 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/26949:
 #0: ffffffff8f3774f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f377308 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/26978:
 #0: ffffffff8f3774f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f377308 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/26980:
 #0: ffffffff8f3774f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f377308 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/26982:
 #0: ffffffff8f3774f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f377308 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/27005:
 #0: ffffffff8f3774f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f377308 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/27007:
 #0: ffffffff8f3774f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f377308 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790
2 locks held by syz-executor/27009:
 #0: ffffffff8f3774f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8f377308 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10d/0x790

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 35 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
 sys_info+0x135/0x170
 watchdog+0xf95/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 20319 Comm: kworker/u8:6 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_dat_purge
RIP: 0010:rcu_is_watching+0x3a/0xb0
Code: e8 bb 83 b3 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd d0 fd 9a 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 8c 68 80 00 48 c7 c3 d8 96 7f 92 49 03 1e 48 89
RSP: 0018:ffffc90007687900 EFLAGS: 00000246
RAX: 1ffffffff1b35fbb RBX: 0000000000000001 RCX: 2e6399cc4d6cd900
RDX: 0000000000000000 RSI: ffffffff8bc07940 RDI: ffffffff8bc07900
RBP: ffffffff8b25ce49 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffffbfff1f03eef R12: 0000000000000000
R13: ffff888034614b58 R14: ffffffff8d9afdd8 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8882a9e3a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005565071c2598 CR3: 0000000175250000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 lock_acquire+0x5f/0x340
 _raw_spin_lock_bh+0x36/0x50
 batadv_dat_purge+0xe9/0x3c0
 process_scheduled_works+0xad1/0x1770
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 ret_from_fork_asm+0x1a/0x30
 </TASK>
