INFO: task syz-executor:10247 blocked for more than 146 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:26232 pid:10247 tgid:10247 ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340
 rwsem_down_write_slowpath+0x883/0x1080 kernel/locking/rwsem.c:1215
 __down_write_common kernel/locking/rwsem.c:1347 [inline]
 __down_write kernel/locking/rwsem.c:1356 [inline]
 down_write+0x1bc/0x200 kernel/locking/rwsem.c:1626
 rdma_dev_exit_net+0x92/0x350 drivers/infiniband/core/device.c:1132
 ops_exit_list net/core/net_namespace.c:199 [inline]
 ops_undo_list+0x49f/0x940 net/core/net_namespace.c:252
 setup_net+0x2f0/0x340 net/core/net_namespace.c:462
 copy_net_ns+0x50e/0x730 net/core/net_namespace.c:579
 create_new_namespaces+0x3e7/0x6a0 kernel/nsproxy.c:132
 unshare_nsproxy_namespaces+0x149/0x190 kernel/nsproxy.c:234
 ksys_unshare+0x57d/0x9f0 kernel/fork.c:3242
 __do_sys_unshare kernel/fork.c:3316 [inline]
 __se_sys_unshare kernel/fork.c:3314 [inline]
 __x64_sys_unshare+0x38/0x50 kernel/fork.c:3314
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3178f9e127
RSP: 002b:00007ffc8beb8628 EFLAGS: 00000202 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f3179215f40 RCX: 00007f3178f9e127
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000000
RBP: 00007f31792167b8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000008
R13: 0000000000000003 R14: 00007ffc8beb8868 R15: 0000000000000000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:2/35:
 #0: ffff88803204e940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88803204e940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90000ab7c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90000ab7c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffffffff8fdc7e00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8fdc7e00 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4746
1 lock held by dhcpcd/5294:
 #0: ffffffff8fdc7e00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8fdc7e00 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x32b/0x1b30 net/ipv4/devinet.c:1120
2 locks held by getty/5386:
 #0: ffff8880369770a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
4 locks held by kworker/1:6/5781:
 #0: ffff88801b7be940 ((wq_completion)infiniband){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801b7be940 ((wq_completion)infiniband){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90004d3fc40 ((work_completion)(&work->work)#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90004d3fc40 ((work_completion)(&work->work)#2){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffff888035c152d0 (&rxe->usdev_lock){+.+.}-{4:4}, at: rxe_query_port+0x7e/0x3d0 drivers/infiniband/sw/rxe/rxe_verbs.c:61
 #3: ffffffff8fdc7e00 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x173/0x7f0 drivers/infiniband/core/verbs.c:2054
10 locks held by kworker/u8:14/9650: