INFO: task syz-executor.1:3875 blocked for more than 143 seconds.
      Not tainted 5.9.0-rc1-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.1  state:D stack:29104 pid: 3875 ppid:   361 flags:0x80004006
Call Trace:
 context_switch kernel/sched/core.c:3778 [inline]
 __schedule+0x889/0x1f70 kernel/sched/core.c:4527
 schedule+0xcd/0x2b0 kernel/sched/core.c:4602
 wdm_flush+0x2e9/0x3c0 drivers/usb/class/cdc-wdm.c:590
 filp_close+0xb4/0x170 fs/open.c:1276
 close_files fs/file.c:401 [inline]
 put_files_struct fs/file.c:429 [inline]
 put_files_struct+0x1d0/0x350 fs/file.c:426
 exit_files+0x7e/0xa0 fs/file.c:458
 do_exit+0xb75/0x2890 kernel/exit.c:801
 do_group_exit+0x125/0x310 kernel/exit.c:903
 get_signal+0x42d/0x1f10 kernel/signal.c:2757
 arch_do_signal+0x88/0x1a00 arch/x86/kernel/signal.c:811
 exit_to_user_mode_loop kernel/entry/common.c:135 [inline]
 exit_to_user_mode_prepare+0xf9/0x150 kernel/entry/common.c:166
 syscall_exit_to_user_mode+0x36/0x260 kernel/entry/common.c:241
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d5b9
Code: Bad RIP value.
RSP: 002b:00007f71ac74bcf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000118d128 RCX: 000000000045d5b9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000118d128
RBP: 000000000118d120 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118d12c
R13: 00007ffd80e95dbf R14: 00007f71ac74c9c0 R15: 000000000118d12c

Showing all locks held in the system:
5 locks held by kworker/1:1/22:
1 lock held by khungtaskd/23:
 #0: ffffffff87313620 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x264 kernel/locking/lockdep.c:5825
1 lock held by in:imklog/231:

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

NMI backtrace for cpu 1
CPU: 1 PID: 23 Comm: khungtaskd Not tainted 5.9.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xf6/0x16e lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x74/0xb6 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1da/0x1f4 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+0xd6a/0xfd0 kernel/hung_task.c:295
 kthread+0x392/0x470 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3566 Comm: kworker/0:5 Not tainted 5.9.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_power_efficient gc_worker
RIP: 0010:debug_lockdep_rcu_enabled+0x23/0x30 kernel/rcu/update.c:291
Code: cc cc cc cc cc cc cc 8b 05 96 47 57 02 85 c0 74 21 8b 05 5c 56 57 02 85 c0 74 17 65 48 8b 04 25 40 ef 01 00 8b 80 9c 08 00 00 <85> c0 0f 94 c0 0f b6 c0 c3 cc cc cc cc 48 c7 c2 40 38 03 00 65 48
RSP: 0018:ffff8881aac57bc0 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff8126c657
RDX: fffffbfff10166b2 RSI: 0000000000000008 RDI: ffffffff880b3588
RBP: 1ffff1103558af7b R08: 0000000000000000 R09: ffffffff880b358f
R10: fffffbfff10166b1 R11: 00000000fa83b2da R12: ffffffff880b7148
R13: ffffffff811abefc R14: 0000000000000000 R15: 0000000000000200
FS:  0000000000000000(0000) GS:ffff8881db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2d12b0b000 CR3: 00000001d265c000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 trace_lock_release include/trace/events/lock.h:58 [inline]
 lock_release+0x55d/0x7f0 kernel/locking/lockdep.c:5022
 seqcount_lockdep_reader_access include/linux/seqlock.h:103 [inline]
 read_seqcount_t_begin include/linux/seqlock.h:311 [inline]
 nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:312 [inline]
 gc_worker+0x1b7/0xc20 net/netfilter/nf_conntrack_core.c:1373
 process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x392/0x470 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294