INFO: task syz-executor.2:20645 can't die for more than 143 seconds.
task:syz-executor.2  state:R  running task     stack:26544 pid:20645 ppid: 17581 flags:0x00004006
Call Trace:
 context_switch kernel/sched/core.c:4955 [inline]
 __schedule+0x940/0x26f0 kernel/sched/core.c:6236
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6408
 __cond_resched+0x13/0x20 kernel/sched/core.c:8121
 spin_lock include/linux/spinlock.h:368 [inline]
 nf_conntrack_lock net/netfilter/nf_conntrack_core.c:87 [inline]
 get_next_corpse net/netfilter/nf_conntrack_core.c:2230 [inline]
 nf_ct_iterate_cleanup+0x1c3/0x450 net/netfilter/nf_conntrack_core.c:2275
 nf_conntrack_cleanup_net_list+0x14c/0x4f0 net/netfilter/nf_conntrack_core.c:2469
 ops_exit_list+0x10d/0x160 net/core/net_namespace.c:171
 setup_net+0x639/0xa30 net/core/net_namespace.c:349
 copy_net_ns+0x319/0x760 net/core/net_namespace.c:470
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x445/0x920 kernel/fork.c:3128
 __do_sys_unshare kernel/fork.c:3199 [inline]
 __se_sys_unshare kernel/fork.c:3197 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3197
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fa2566d5739
RSP: 002b:00007fa253c4c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fa2567d9f80 RCX: 00007fa2566d5739
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000060000000
RBP: 00007fa25672fcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa2567d9f80
R13: 00007ffc48fc83cf R14: 00007fa253c4c300 R15: 0000000000022000
INFO: task syz-executor.1:20666 can't die for more than 143 seconds.
task:syz-executor.1  state:R  running task     stack:27176 pid:20666 ppid: 17668 flags:0x00004006
Call Trace:
 context_switch kernel/sched/core.c:4955 [inline]
 __schedule+0x940/0x26f0 kernel/sched/core.c:6236

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8b980960 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446
1 lock held by in:imklog/6242:
3 locks held by kworker/1:6/8518:
 #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
 #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline]
 #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline]
 #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2268
 #1: ffffc900171bfdb0 (fqdir_free_work){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2272
 #2: ffffffff8b989bf0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x44/0x440 kernel/rcu/tree.c:3985
4 locks held by kworker/u4:7/9559:
 #0: ffff88801204b138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff88801204b138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff88801204b138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline]
 #0: ffff88801204b138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline]
 #0: ffff88801204b138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline]
 #0: ffff88801204b138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2268
 #1: ffffc9000682fdb0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2272
 #2: ffffffff8d0d1290 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb00 net/core/net_namespace.c:555
 #3: ffffffff8b989bf0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x44/0x440 kernel/rcu/tree.c:3985
1 lock held by syz-executor.2/20645:
2 locks held by syz-executor.1/20666:
 #0: ffffffff8d0d1290 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x2f5/0x760 net/core/net_namespace.c:466
 #1: ffffffff8b989bf0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x44/0x440 kernel/rcu/tree.c:3985

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