INFO: task systemd-udevd:20557 blocked for more than 143 seconds.
      Tainted: G        W         5.13.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:systemd-udevd   state:D stack:27784 pid:20557 ppid:  4862 flags:0x00004000
Call Trace:
 context_switch kernel/sched/core.c:4683 [inline]
 __schedule+0xc07/0x11f0 kernel/sched/core.c:5940
 schedule+0x14b/0x210 kernel/sched/core.c:6019
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078
 __mutex_lock_common+0x116f/0x3770 kernel/locking/mutex.c:1036
 __mutex_lock kernel/locking/mutex.c:1104 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119
 del_gendisk+0x86/0x610 block/genhd.c:587
 nbd_dev_remove drivers/block/nbd.c:224 [inline]
 nbd_put+0x8d/0x170 drivers/block/nbd.c:246
 blkdev_put_whole fs/block_dev.c:1277 [inline]
 blkdev_put+0x470/0x810 fs/block_dev.c:1574
 blkdev_close+0x7a/0xa0 fs/block_dev.c:1584
 __fput+0x352/0x7b0 fs/file_table.c:280
 task_work_run+0x146/0x1c0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x201/0x220 kernel/entry/common.c:209
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x26/0x60 kernel/entry/common.c:302
 do_syscall_64+0x4c/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fa2f799c270
RSP: 002b:00007ffc7c0434f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007fa2f799c270
RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 00007fa2f8856710 R08: 000000000000004a R09: 0000000000000008
R10: 000055c4900a7518 R11: 0000000000000246 R12: 0000000000000000
R13: 000055c4900a7bc0 R14: 0000000000000003 R15: 000000000000000e
INFO: task syz-executor.1:20570 blocked for more than 143 seconds.
      Tainted: G        W         5.13.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.1  state:D stack:25120 pid:20570 ppid:  8445 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4683 [inline]
 __schedule+0xc07/0x11f0 kernel/sched/core.c:5940
 schedule+0x14b/0x210 kernel/sched/core.c:6019
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6078
 __mutex_lock_common+0x116f/0x3770 kernel/locking/mutex.c:1036
 __mutex_lock kernel/locking/mutex.c:1104 [inline]
 mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1119
 nbd_genl_connect+0x24f/0x1aa0 drivers/block/nbd.c:1801
 genl_family_rcv_msg_doit net/netlink/genetlink.c:739 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
 genl_rcv_msg+0xfb4/0x13c0 net/netlink/genetlink.c:800
 netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2504
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
 netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
 netlink_unicast+0x7de/0x9b0 net/netlink/af_netlink.c:1340
 netlink_sendmsg+0xaa6/0xe90 net/netlink/af_netlink.c:1929
 sock_sendmsg_nosec net/socket.c:702 [inline]
 sock_sendmsg net/socket.c:722 [inline]
 ____sys_sendmsg+0x5a2/0x900 net/socket.c:2385
 ___sys_sendmsg net/socket.c:2439 [inline]
 __sys_sendmsg+0x319/0x400 net/socket.c:2468
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
RSP: 002b:00007f3dd490c188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000800 RSI: 0000000020000340 RDI: 0000000000000006
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffc52fe7e5f R14: 00007f3dd490c300 R15: 0000000000022000
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 PID: 1639 Comm: khungtaskd Tainted: G        W         5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack_lvl+0x1d3/0x29f lib/dump_stack.c:96
 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x191/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd06/0xd50 kernel/hung_task.c:294
 kthread+0x453/0x480 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 9007 Comm: kworker/1:4 Tainted: G        W         5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:lock_acquire+0x93/0x4a0 kernel/locking/lockdep.c:5593
Code: f2 4b 89 44 25 00 43 c7 44 25 09 f2 f2 f2 00 43 c7 44 25 11 f3 f3 f3 f3 66 43 c7 44 25 15 f3 f3 43 c6 44 25 17 f3 89 54 24 30 <89> 4c 24 18 4c 89 4c 24 28 ff 75 10 e8 fc 03 00 00 48 83 c4 08 48
RSP: 0018:ffffc90001fcf820 EFLAGS: 00000806
RAX: f2f2f200f1f1f1f1 RBX: ffff8880119b2e60 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880119b2e60
RBP: ffffc90001fcf968 R08: 0000000000000001 R09: 0000000000000000
R10: fffffbfff1c7320e R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff920003f9f0c R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f90c73c2018 CR3: 0000000028640000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xb3/0x100 kernel/locking/spinlock.c:159
 _extract_crng+0xf8/0x350 drivers/char/random.c:997
 extract_crng drivers/char/random.c:1016 [inline]
 _get_random_bytes+0x1b4/0x230 drivers/char/random.c:1538
 eth_random_addr include/linux/etherdevice.h:225 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:671 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:721 [inline]
 nsim_dev_trap_report_work+0x32b/0xb20 drivers/net/netdevsim/dev.c:762
 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276
 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422
 kthread+0x453/0x480 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295