infiniband syz0: set down
infiniband syz0: added ipvlan1
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.1345/11227 is trying to acquire lock:
ffffffff8ee8f980 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc_noprof+0xbc/0x720

but task is already holding lock:
ffffffff8ebf9040 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0xa4f/0x1fe0

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #7 (wq_pool_mutex){+.+.}-{4:4}:
       __mutex_lock+0x19d/0x1550
       __alloc_workqueue+0xa4f/0x1fe0
       alloc_workqueue_noprof+0xe3/0x210
       padata_alloc+0xbe/0x360
       pcrypt_init_padata+0x27/0x100
       pcrypt_init+0x60/0xc0
       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

-> #6 (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

-> #5 (&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

-> #4 (&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

-> #3 (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+0x6cb/0xe30
       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

-> #2 (&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

-> #1 (&q->q_usage_counter(io)#49){++++}-{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

-> #0 (fs_reclaim){+.+.}-{0:0}:
       __lock_acquire+0x15ff/0x2e50
       lock_acquire+0x115/0x350
       fs_reclaim_acquire+0x71/0x100
       __kmalloc_noprof+0xbc/0x720
       apply_wqattrs_prepare+0xee/0xdc0
       __alloc_workqueue+0x11be/0x1fe0
       alloc_workqueue_noprof+0xe3/0x210
       ib_mad_init_device+0x993/0x2150
       add_client_context+0x37c/0x7b0
       enable_device_and_get+0x19c/0x3e0
       ib_register_device+0xdc8/0x1080
       rxe_register_device+0x1e3/0x350
       rxe_net_add+0x81/0x110
       rxe_newlink+0xf4/0x1c0
       nldev_newlink+0x5be/0x650
       rdma_nl_rcv+0x6ef/0xa40
       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

other info that might help us debug this:

Chain exists of:
  fs_reclaim --> cpu_hotplug_lock --> wq_pool_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(wq_pool_mutex);
                               lock(cpu_hotplug_lock);
                               lock(wq_pool_mutex);
  lock(fs_reclaim);

 *** DEADLOCK ***

locks held by syz.0.1345/11227: 6, last CPU#1:
 #0: ffffffff9ad81a28 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x33d/0xa40
 #1: ffffffff8ffac8e8 (link_ops_rwsem){++++}-{4:4}, at: nldev_newlink+0x42b/0x650
 #2: ffffffff8ff9da08 (devices_rwsem){++++}-{4:4}, at: enable_device_and_get+0xff/0x3e0
 #3: ffffffff8ff9dd08 (clients_rwsem){++++}-{4:4}, at: enable_device_and_get+0x165/0x3e0
 #4: ffff88811d5f8658 (&device->client_data_rwsem){++++}-{4:4}, at: add_client_context+0x33e/0x7b0
 #5: ffffffff8ebf9040 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0xa4f/0x1fe0

stack backtrace:
CPU: 1 UID: 0 PID: 11227 Comm: syz.0.1345 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
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_circular_bug+0x2e2/0x300
 check_noncircular+0x12f/0x150
 __lock_acquire+0x15ff/0x2e50
 lock_acquire+0x115/0x350
 fs_reclaim_acquire+0x71/0x100
 __kmalloc_noprof+0xbc/0x720
 apply_wqattrs_prepare+0xee/0xdc0
 __alloc_workqueue+0x11be/0x1fe0
 alloc_workqueue_noprof+0xe3/0x210
 ib_mad_init_device+0x993/0x2150
 add_client_context+0x37c/0x7b0
 enable_device_and_get+0x19c/0x3e0
 ib_register_device+0xdc8/0x1080
 rxe_register_device+0x1e3/0x350
 rxe_net_add+0x81/0x110
 rxe_newlink+0xf4/0x1c0
 nldev_newlink+0x5be/0x650
 rdma_nl_rcv+0x6ef/0xa40
 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
RIP: 0033:0x7f1f6c99e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1f6d896028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f1f6cc25fa0 RCX: 00007f1f6c99e159
RDX: 000000002400c000 RSI: 00002000000000c0 RDI: 0000000000000006
RBP: 00007f1f6ca35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1f6cc26038 R14: 00007f1f6cc25fa0 R15: 00007ffe9cbda3b8
 </TASK>
smbdirect: ib_dev[syz0]: added: IB_CA max_fast_reg_page_list_len=512 device_cap_flags=0x1c001223c76 kernel_cap_flags=0x14 page_size_cap=0xfffff000
smbdirect: ib_dev[syz0]: num_ports=1 max_qp_rd_atom=128 max_qp_init_rd_atom=128 max_sgl_rd=0 max_sge_rd=32 max_cqe=32767 max_qp_wr=1048576 max_send_sge=32 max_recv_sge=32
smbdirect: ib_dev[syz0]PORT[1]: iwarp=0 ib=0 roce=1 v1=0 v2=1 core_cap_flags=0x803005
RDS/IB: syz0: added
smc: adding ib device syz0 with port count 1
smc:    ib device syz0 port 1 has no pnetid
