INFO: task syz.1.2176:13035 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2176      state:D stack:25568 pid:13035 tgid:13034 ppid:5606   task_flags:0x480140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 blk_mq_freeze_queue_wait+0x101/0x180
 queue_limits_commit_update_frozen+0x55/0xd0
 nbd_set_size+0x454/0x680
 nbd_genl_reconfigure+0x7f5/0x1ea0
 genl_family_rcv_msg_doit+0x22a/0x330
 genl_rcv_msg+0x61c/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x75c/0x8e0
 netlink_sendmsg+0x813/0xb40
 ____sys_sendmsg+0x972/0x9f0
 ___sys_sendmsg+0x2a5/0x360
 __x64_sys_sendmsg+0x1bd/0x2a0
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f066e39cdd9
RSP: 002b:00007f066f185028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f066e615fa0 RCX: 00007f066e39cdd9
RDX: 0000000000020000 RSI: 0000200000000280 RDI: 0000000000000008
RBP: 00007f066e432d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f066e616038 R14: 00007f066e615fa0 R15: 00007ffc643dadd8
 </TASK>
INFO: task syz.0.2177:13054 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.2177      state:D stack:25984 pid:13054 tgid:13052 ppid:5614   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7f7/0x1550
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x75c/0x8e0
 netlink_sendmsg+0x813/0xb40
 __sys_sendto+0x672/0x710
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2ea875d60e
RSP: 002b:00007f2ea9728e88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f2ea972a6c0 RCX: 00007f2ea875d60e
RDX: 0000000000000020 RSI: 00007f2ea9729000 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00007f2ea9728f04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 00007f2ea9728f58 R14: 00007f2ea9729000 R15: 0000000000000000
 </TASK>
INFO: task syz.2.2178:13055 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.2178      state:D stack:28528 pid:13055 tgid:13053 ppid:5612   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 __schedule+0x17b4/0x5680
 schedule+0x164/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7f7/0x1550
 genl_rcv_msg+0x10b/0x7a0
 netlink_rcv_skb+0x232/0x4b0
 genl_rcv+0x28/0x40
 netlink_unicast+0x75c/0x8e0
 netlink_sendmsg+0x813/0xb40
 __sys_sendto+0x672/0x710
 __x64_sys_sendto+0xde/0x100
 do_syscall_64+0x15f/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f921c95d60e
RSP: 002b:00007f921d79fe88 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f921d7a16c0 RCX: 00007f921c95d60e
RDX: 0000000000000020 RSI: 00007f921d7a0000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007f921d79ff04 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007f921d79ff58 R14: 00007f921d7a0000 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/35:
 #0: ffffffff8e95cd60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
2 locks held by getty/5435:
 #0: ffff88817124a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900023092e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0
1 lock held by udevd/5759:
 #0: ffff888103f64350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
1 lock held by udevd/6621:
 #0: ffff888104340350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30
6 locks held by syz.1.2176/13035:
 #0: ffffffff8fe3dd88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3dbc0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
 #2: ffff88810433ca60 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_genl_reconfigure+0x4c1/0x1ea0
 #3: ffff88810430be78 (&q->limits_lock){+.+.}-{4:4}, at: nbd_set_size+0x263/0x680
 #4: ffff88810430b840 (&q->q_usage_counter(io)#50){++++}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0
 #5: ffff88810430b878 (&q->q_usage_counter(queue)#34){+.+.}-{0:0}, at: queue_limits_commit_update_frozen+0x55/0xd0
2 locks held by syz.0.2177/13054:
 #0: ffffffff8fe3dd88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3dbc0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz.2.2178/13055:
 #0: ffffffff8fe3dd88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3dbc0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/13073:
 #0: ffffffff8fe3dd88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3dbc0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/13092:
 #0: ffffffff8fe3dd88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3dbc0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/13095:
 #0: ffffffff8fe3dd88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3dbc0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/13131:
 #0: ffffffff8fe3dd88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3dbc0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/13149:
 #0: ffffffff8fe3dd88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3dbc0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/13167:
 #0: ffffffff8fe3dd88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3dbc0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/13186:
 #0: ffffffff8fe3dd88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3dbc0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/13204:
 #0: ffffffff8fe3dd88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3dbc0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0
2 locks held by syz-executor/13222:
 #0: ffffffff8fe3dd88 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40
 #1: ffffffff8fe3dbc0 (genl_mutex){+.+.}-{4:4}, at: genl_rcv_msg+0x10b/0x7a0

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

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+0xe8/0x150
 nmi_cpu_backtrace+0x274/0x2d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 sys_info+0x135/0x170
 watchdog+0xfd3/0x1030
 kthread+0x388/0x470
 ret_from_fork+0x514/0xb70
 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: 0 Comm: swapper/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
RIP: 0010:pick_task_fair+0xdb/0x2a0
Code: ff e8 59 e2 01 00 0f 1f 44 00 00 31 ed 4c 89 ff be 01 00 00 00 e8 a5 f3 01 00 4c 8d 78 59 4c 89 f9 48 c1 e9 03 42 0f b6 0c 29 <84> c9 75 6b 41 80 3f 00 74 34 48 8b 7c 24 08 48 89 c6 ba 21 00 00
RSP: 0018:ffffc900001979a0 EFLAGS: 00000802
RAX: ffff888161aa1e00 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88823c63ba08 RSI: 0000000000000001 RDI: ffff88823c63af50
RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000032f68 R12: 0000000000000000
R13: dffffc0000000000 R14: 1ffff110478c75e2 R15: ffff888161aa1e59
FS:  0000000000000000(0000) GS:ffff8882a9293000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe7464edac CR3: 000000016f1d0000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 pick_next_task_fair+0x173/0x1ab0
 __pick_next_task+0xe6/0x480
 __schedule+0x974/0x5680
 schedule_idle+0x51/0x90
 do_idle+0x58a/0x5f0
 cpu_startup_entry+0x43/0x60
 start_secondary+0x101/0x110
 common_startup_64+0x13e/0x147
 </TASK>
