netdevsim netdevsim2 eth3 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0
netdevsim netdevsim2 eth3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/u8:2/5636 is trying to acquire lock:
ffff8881012d4180 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x4e/0x140

but task is already holding lock:
ffff8881012d42a0 (&root->kernfs_supers_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3f/0x140

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #10 (&root->kernfs_supers_rwsem){++++}-{4:4}:
       down_read+0x4a/0x330
       kernfs_remove_by_name_ns+0x3f/0x140
       internal_create_group+0x58e/0x1180
       sysfs_update_groups+0x60/0x130
       pmu_dev_alloc+0x29b/0x300
       perf_event_sysfs_init+0x76/0x100
       do_one_initcall+0x250/0x870
       do_initcall_level+0x10a/0x1a0
       do_initcalls+0x59/0xa0
       kernel_init_freeable+0x29d/0x3e0
       kernel_init+0x22/0x1d0
       ret_from_fork+0x514/0xb70
       ret_from_fork_asm+0x1a/0x30

-> #9 (pmus_lock){+.+.}-{4:4}:
       __mutex_lock+0x19d/0x1550
       perf_event_init_cpu+0x1d1/0x7a0
       cpuhp_invoke_callback+0x434/0x810
       cpuhp_thread_fun+0x362/0x780
       smpboot_thread_fn+0x565/0xa70
       kthread+0x38b/0x480
       ret_from_fork+0x514/0xb70
       ret_from_fork_asm+0x1a/0x30

-> #8 (cpuhp_state-up){+.+.}-{0:0}:
       cpuhp_thread_fun+0x127/0x780
       smpboot_thread_fn+0x565/0xa70
       kthread+0x38b/0x480
       ret_from_fork+0x514/0xb70
       ret_from_fork_asm+0x1a/0x30

-> #7 (cpu_hotplug_lock){++++}-{0:0}:
       cpus_read_lock+0x42/0x160
       static_key_slow_inc+0x12/0x30
       nbd_genl_reconnect_sock_cb+0x69a/0xbb0
       nbd_genl_foreach_sock+0x265/0x450
       nbd_genl_reconfigure+0xbbb/0x1040
       genl_family_rcv_msg_doit+0x233/0x340
       genl_rcv_msg+0x614/0x7a0
       netlink_rcv_skb+0x226/0x4a0
       genl_rcv+0x28/0x40
       netlink_unicast+0x7bd/0x940
       netlink_sendmsg+0x813/0xb40
       sock_sendmsg_nosec+0x13a/0x180
       ____sys_sendmsg+0x54e/0x850
       ___sys_sendmsg+0x2a5/0x360
       __x64_sys_sendmsg+0x1b1/0x290
       do_syscall_64+0x166/0x520
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #6 (&nsock->tx_lock){+.+.}-{4:4}:
       __mutex_lock+0x19d/0x1550
       nbd_queue_rq+0x373/0xff0
       blk_mq_dispatch_rq_list+0x499/0x1990
       __blk_mq_sched_dispatch_requests+0xd36/0x1580
       blk_mq_sched_dispatch_requests+0xd7/0x190
       blk_mq_run_work_fn+0x16c/0x300
       process_scheduled_works+0xc3d/0x1630
       worker_thread+0xa47/0xfb0
       kthread+0x38b/0x480
       ret_from_fork+0x514/0xb70
       ret_from_fork_asm+0x1a/0x30

-> #5 (&cmd->lock){+.+.}-{4:4}:
       __mutex_lock+0x19d/0x1550
       nbd_queue_rq+0xc1/0xff0
       blk_mq_dispatch_rq_list+0x499/0x1990
       __blk_mq_sched_dispatch_requests+0xd36/0x1580
       blk_mq_sched_dispatch_requests+0xd7/0x190
       blk_mq_run_work_fn+0x16c/0x300
       process_scheduled_works+0xc3d/0x1630
       worker_thread+0xa47/0xfb0
       kthread+0x38b/0x480
       ret_from_fork+0x514/0xb70
       ret_from_fork_asm+0x1a/0x30

-> #4 (set->srcu){.+.+}-{0:0}:
       __synchronize_srcu+0xc9/0x2f0
       elevator_switch+0x1e8/0x7b0
       elevator_change+0x2fa/0x480
       elevator_set_default+0x375/0x440
       blk_register_queue+0x3f3/0x4e0
       __add_disk+0x6b8/0xdb0
       add_disk_fwnode+0x100/0x3a0
       nbd_dev_add+0x733/0xb60
       nbd_init+0x168/0x1f0
       do_one_initcall+0x250/0x870
       do_initcall_level+0x10a/0x1a0
       do_initcalls+0x59/0xa0
       kernel_init_freeable+0x29d/0x3e0
       kernel_init+0x22/0x1d0
       ret_from_fork+0x514/0xb70
       ret_from_fork_asm+0x1a/0x30

-> #3 (&q->elevator_lock){+.+.}-{4:4}:
       __mutex_lock+0x19d/0x1550
       elevator_change+0x1af/0x480
       elevator_set_none+0xb5/0x140
       blk_mq_update_nr_hw_queues+0x5ef/0x19f0
       nbd_start_device+0x189/0xb30
       nbd_genl_connect+0x167d/0x1cd0
       genl_family_rcv_msg_doit+0x233/0x340
       genl_rcv_msg+0x614/0x7a0
       netlink_rcv_skb+0x226/0x4a0
       genl_rcv+0x28/0x40
       netlink_unicast+0x7bd/0x940
       netlink_sendmsg+0x813/0xb40
       sock_sendmsg_nosec+0x13a/0x180
       ____sys_sendmsg+0x54e/0x850
       ___sys_sendmsg+0x2a5/0x360
       __x64_sys_sendmsg+0x1b1/0x290
       do_syscall_64+0x166/0x520
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&q->q_usage_counter(io)#52){++++}-{0:0}:
       blk_alloc_queue+0x544/0x690
       __blk_mq_alloc_disk+0x194/0x390
       nbd_dev_add+0x494/0xb60
       nbd_init+0x168/0x1f0
       do_one_initcall+0x250/0x870
       do_initcall_level+0x10a/0x1a0
       do_initcalls+0x59/0xa0
       kernel_init_freeable+0x29d/0x3e0
       kernel_init+0x22/0x1d0
       ret_from_fork+0x514/0xb70
       ret_from_fork_asm+0x1a/0x30

-> #1 (fs_reclaim){+.+.}-{0:0}:
       fs_reclaim_acquire+0x71/0x100
       kmem_cache_alloc_lru_noprof+0x65/0x5f0
       alloc_inode+0xb8/0x1b0
       iget_locked+0x131/0x6a0
       kernfs_get_inode+0x4f/0x770
       kernfs_get_tree+0x5cd/0x980
       vfs_get_tree+0x92/0x2a0
       do_new_mount+0x319/0xdc0
       __se_sys_mount+0x31d/0x420
       do_syscall_64+0x166/0x520
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&root->kernfs_rwsem){++++}-{4:4}:
       __lock_acquire+0x164c/0x2de0
       lock_acquire+0x115/0x350
       down_write+0x96/0x200
       kernfs_remove_by_name_ns+0x4e/0x140
       sysfs_remove_group+0x101/0x2e0
       sysfs_remove_groups+0x54/0xb0
       net_rx_queue_update_kobjects+0x6b7/0x780
       netdev_unregister_kobject+0xff/0x450
       unregister_netdevice_many_notify+0x1be1/0x2140
       unregister_netdevice_queue+0x2f5/0x340
       nsim_destroy+0x275/0x800
       __nsim_dev_port_del+0x14e/0x200
       nsim_dev_reload_destroy+0x288/0x490
       nsim_dev_reload_down+0x8a/0xc0
       devlink_reload+0x1c5/0x890
       devlink_pernet_pre_exit+0x1ff/0x420
       ops_undo_list+0x17d/0x8d0
       cleanup_net+0x572/0x810
       process_scheduled_works+0xc3d/0x1630
       worker_thread+0xa47/0xfb0
       kthread+0x38b/0x480
       ret_from_fork+0x514/0xb70
       ret_from_fork_asm+0x1a/0x30

other info that might help us debug this:

Chain exists of:
  &root->kernfs_rwsem --> pmus_lock --> &root->kernfs_supers_rwsem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(&root->kernfs_supers_rwsem);
                               lock(pmus_lock);
                               lock(&root->kernfs_supers_rwsem);
  lock(&root->kernfs_rwsem);

 *** DEADLOCK ***

locks held by kworker/u8:2/5636: 7, last CPU#0:
 #0: ffff8881012d5940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #1: ffffc90004f77c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630
 #2: ffffffff90244b48 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf5/0x810
 #3: ffff888021833128 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420
 #4: ffff888021831258 (&devlink->lock_key){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420
 #5: ffffffff902533a0 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0x173/0x800
 #6: ffff8881012d42a0 (&root->kernfs_supers_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3f/0x140

stack backtrace:
CPU: 0 UID: 0 PID: 5636 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_circular_bug+0x2e2/0x300
 check_noncircular+0x12f/0x150
 __lock_acquire+0x164c/0x2de0
 lock_acquire+0x115/0x350
 down_write+0x96/0x200
 kernfs_remove_by_name_ns+0x4e/0x140
 sysfs_remove_group+0x101/0x2e0
 sysfs_remove_groups+0x54/0xb0
 net_rx_queue_update_kobjects+0x6b7/0x780
 netdev_unregister_kobject+0xff/0x450
 unregister_netdevice_many_notify+0x1be1/0x2140
 unregister_netdevice_queue+0x2f5/0x340
 nsim_destroy+0x275/0x800
 __nsim_dev_port_del+0x14e/0x200
 nsim_dev_reload_destroy+0x288/0x490
 nsim_dev_reload_down+0x8a/0xc0
 devlink_reload+0x1c5/0x890
 devlink_pernet_pre_exit+0x1ff/0x420
 ops_undo_list+0x17d/0x8d0
 cleanup_net+0x572/0x810
 process_scheduled_works+0xc3d/0x1630
 worker_thread+0xa47/0xfb0
 kthread+0x38b/0x480
 ret_from_fork+0x514/0xb70
 ret_from_fork_asm+0x1a/0x30
 </TASK>
netdevsim netdevsim2 eth2 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0
netdevsim netdevsim2 eth2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim2 eth1 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0
netdevsim netdevsim2 eth1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim2 eth0 (unregistering): unset [0, 0] type 1 family 0 port 8472 - 0
netdevsim netdevsim2 eth0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
batman_adv: batadv0: Interface deactivated: ip6gretap5
batman_adv: batadv0: Interface deactivated: gretap5
bond1 (unregistering): (slave ip6gretap1): Releasing active interface
bond2 (unregistering): (slave ip6gretap2): Releasing backup interface
bond21 (unregistering): (slave ip6gre8): Releasing backup interface
batman_adv: batadv0: Removing interface: ip6gretap5
batman_adv: batadv0: Removing interface: ip6gretap7
bond3 (unregistering): (slave erspan1): Releasing active interface
bond23 (unregistering): (slave gretap6): Releasing active interface
batman_adv: batadv0: Removing interface: gretap5
bond43 (unregistering): (slave gretap7): Releasing active interface
bond0 (unregistering): left promiscuous mode
bond0 (unregistering): Released all slaves
bond1 (unregistering): Released all slaves
bond2 (unregistering): Released all slaves
bond3 (unregistering): Released all slaves
bond4 (unregistering): Released all slaves
bond5 (unregistering): Released all slaves
bond6 (unregistering): Released all slaves
bond7 (unregistering): Released all slaves
bond8 (unregistering): Released all slaves
bond9 (unregistering): Released all slaves
bond10 (unregistering): Released all slaves
bond11 (unregistering): Released all slaves
bond12 (unregistering): Released all slaves
bond13 (unregistering): Released all slaves
bond14 (unregistering): left promiscuous mode
macvlan2 (unregistering): left promiscuous mode
team0: Port device macvlan2 removed
bond14 (unregistering): Released all slaves
bond15 (unregistering): Released all slaves
bond16 (unregistering): Released all slaves
bond17 (unregistering): Released all slaves
bond18 (unregistering): Released all slaves
bond20 (unregistering): Released all slaves
bond21 (unregistering): Released all slaves
bond22 (unregistering): Released all slaves
bond23 (unregistering): Released all slaves
bond24 (unregistering): Released all slaves
bond25 (unregistering): Released all slaves
bond26 (unregistering): Released all slaves
bond27 (unregistering): Released all slaves
bond28 (unregistering): Released all slaves
bond29 (unregistering): Released all slaves
bond30 (unregistering): Released all slaves
bond31 (unregistering): Released all slaves
bond32 (unregistering): Released all slaves
bond33 (unregistering): Released all slaves
bond34 (unregistering): Released all slaves
bond35 (unregistering): Released all slaves
bond36 (unregistering): Released all slaves
bond19 (unregistering): Released all slaves
bond37 (unregistering): Released all slaves
bond38 (unregistering): Released all slaves
bond39 (unregistering): Released all slaves
bond40 (unregistering): Released all slaves
bond41 (unregistering): Released all slaves
bond42 (unregistering): Released all slaves
bond43 (unregistering): Released all slaves
bond44 (unregistering): Released all slaves
bond45 (unregistering): Released all slaves
bond46 (unregistering): Released all slaves
bond47 (unregistering): Released all slaves
bond48 (unregistering): Released all slaves
bond49 (unregistering): Released all slaves
bond50 (unregistering): Released all slaves
bond51 (unregistering): Released all slaves
bond52 (unregistering): Released all slaves
bond53 (unregistering): Released all slaves
bond54 (unregistering): Released all slaves
bond55 (unregistering): Released all slaves
team0: Port device macvlan3 removed
bond56 (unregistering): Released all slaves
bond57 (unregistering): Released all slaves
bond58 (unregistering): Released all slaves
bond59 (unregistering): Released all slaves
bond60 (unregistering): Released all slaves
bond61 (unregistering): Released all slaves
: left promiscuous mode
tipc: Disabling bearer <ib:veth1_to_team>
tipc: Disabling bearer <eth:syzkaller0>
tipc: Disabling bearer <udp:syz2>
tipc: Left network mode
IPVS: stopping backup sync thread 18516 ...
batman_adv: batadv0: Interface deactivated: syzkaller0
batman_adv: batadv0: Removing interface: syzkaller0
team0: left promiscuous mode
hsr_slave_0: left promiscuous mode
hsr_slave_1: left promiscuous mode
veth1_vlan: left promiscuous mode
veth0_vlan: left promiscuous mode
IPVS: stop unused estimator thread 0...
netdevsim netdevsim7 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim7 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim7 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim7 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim8 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim8 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim8 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
netdevsim netdevsim8 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0
bridge_slave_1: left allmulticast mode
bridge_slave_1: left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
bridge_slave_0: left allmulticast mode
bridge_slave_0: left promiscuous mode
bridge0: port 1(bridge_slave_0) entered disabled state
bridge_slave_1: left allmulticast mode
bridge_slave_1: left promiscuous mode
bridge0: port 2(bridge_slave_1) entered disabled state
bridge_slave_0: left allmulticast mode
bridge_slave_0: left promiscuous mode
bridge0: port 1(bridge_slave_0) entered disabled state
bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
bond0 (unregistering): Released all slaves
bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
bond0 (unregistering): Released all slaves
hsr_slave_0: left promiscuous mode
hsr_slave_1: left promiscuous mode
batman_adv: batadv0: Interface deactivated: batadv_slave_0
batman_adv: batadv0: Removing interface: batadv_slave_0
batman_adv: batadv0: Interface deactivated: batadv_slave_1
batman_adv: batadv0: Removing interface: batadv_slave_1
hsr_slave_0: left promiscuous mode
hsr_slave_1: left promiscuous mode
batman_adv: batadv0: Interface deactivated: batadv_slave_0
batman_adv: batadv0: Removing interface: batadv_slave_0
batman_adv: batadv0: Interface deactivated: batadv_slave_1
batman_adv: batadv0: Removing interface: batadv_slave_1
veth1_macvtap: left promiscuous mode
veth0_macvtap: left promiscuous mode
veth1_vlan: left promiscuous mode
veth0_vlan: left promiscuous mode
veth1_macvtap: left promiscuous mode
veth0_macvtap: left promiscuous mode
veth1_vlan: left promiscuous mode
veth0_vlan: left promiscuous mode
team0 (unregistering): Port device team_slave_1 removed
team0 (unregistering): Port device team_slave_0 removed
team0 (unregistering): Port device team_slave_1 removed
team0 (unregistering): Port device team_slave_0 removed
