INFO: task syz-executor.0:24011 blocked for more than 143 seconds.
      Not tainted 5.7.0-rc1-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D26672 24011   7184 0x80004006
Call Trace:
 context_switch kernel/sched/core.c:3372 [inline]
 __schedule+0x805/0xc90 kernel/sched/core.c:4088
 schedule+0x188/0x220 kernel/sched/core.c:4163
 rwsem_down_write_slowpath+0x7d0/0xd60 kernel/locking/rwsem.c:1235
 __down_write kernel/locking/rwsem.c:1389 [inline]
 down_write+0x125/0x130 kernel/locking/rwsem.c:1532
 unregister_netdevice_notifier+0x30/0x380 net/core/dev.c:1776
 inode_lock include/linux/fs.h:797 [inline]
 __sock_release net/socket.c:604 [inline]
 sock_close+0x94/0x260 net/socket.c:1283
 bcm_release+0x77/0x800 net/can/bcm.c:1474
 atomic64_set include/asm-generic/atomic-instrumented.h:854 [inline]
 atomic_long_set include/asm-generic/atomic-long.h:40 [inline]
 rwsem_set_owner kernel/locking/rwsem.c:176 [inline]
 __down_write kernel/locking/rwsem.c:1391 [inline]
 down_write+0xcd/0x130 kernel/locking/rwsem.c:1532
 __sock_release net/socket.c:605 [inline]
 sock_close+0xd8/0x260 net/socket.c:1283
 sock_mmap+0x90/0x90 net/socket.c:1278
 __fput+0x2ed/0x750 fs/file_table.c:280
 task_work_run+0x147/0x1d0 kernel/task_work.c:123
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x5ef/0x1f80 kernel/exit.c:795
 do_group_exit+0x15e/0x2c0 kernel/exit.c:893
 get_signal+0x13cf/0x1d60 kernel/signal.c:2739
 do_signal+0x33/0x610 arch/x86/kernel/signal.c:784
 rcu_read_unlock_sched include/linux/rcupdate.h:732 [inline]
 __fd_install+0x251/0x490 fs/file.c:613
 exit_to_usermode_loop arch/x86/entry/common.c:148 [inline]
 prepare_exit_to_usermode+0x280/0x600 arch/x86/entry/common.c:196
 exit_to_usermode_loop arch/x86/entry/common.c:161 [inline]
 prepare_exit_to_usermode+0x32a/0x600 arch/x86/entry/common.c:196
 syscall_return_slowpath+0xf9/0x420 arch/x86/entry/common.c:278
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Showing all locks held in the system:
3 locks held by kworker/u4:2/93:
 #0: ffff8880a9bb4938 ((wq_completion)netns){+.+.}-{0:0}, at: spin_unlock_irq include/linux/spinlock.h:403 [inline]
 #0: ffff8880a9bb4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x6df/0xfd0 kernel/workqueue.c:2241
 #1: ffffc90000e87d80 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x71e/0xfd0 kernel/workqueue.c:2243
 #2: ffffffff895ac1f0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xac/0xb80 net/core/net_namespace.c:565
1 lock held by khungtaskd/1129:
 #0: ffffffff892e8590 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 net/mptcp/pm_netlink.c:858
1 lock held by in:imklog/6846:
 #0: ffff8880a88d5df0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x25d/0x2f0 fs/file.c:826
2 locks held by syz-executor.0/24011:
 #0: ffff888025b69750 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:797 [inline]
 #0: ffff888025b69750 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: __sock_release net/socket.c:604 [inline]
 #0: ffff888025b69750 (&sb->s_type->i_mutex_key#14){+.+.}-{3:3}, at: sock_close+0x94/0x260 net/socket.c:1283
 #1: ffffffff895ac1f0 (pernet_ops_rwsem){++++}-{3:3}, at: unregister_netdevice_notifier+0x30/0x380 net/core/dev.c:1776

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

NMI backtrace for cpu 1
CPU: 1 PID: 1129 Comm: khungtaskd Not tainted 5.7.0-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+0x1e9/0x30e lib/dump_stack.c:118
 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101
 arch_trigger_cpumask_backtrace+0x10/0x10 arch/x86/kernel/apic/hw_nmi.c:38
 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62
 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline]
 watchdog+0xd2a/0xd40 kernel/hung_task.c:289
 kthread+0x353/0x380 kernel/kthread.c:268
 hungtask_pm_notify+0x50/0x50 kernel/hung_task.c:265
 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60