infiniband syz2: set down
infiniband syz2: added wg2
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.4.2307/14243 is trying to acquire lock:
ffffffff8ee8f980 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:316 [inline]
ffffffff8ee8f980 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4636 [inline]
ffffffff8ee8f980 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4974 [inline]
ffffffff8ee8f980 (fs_reclaim){+.+.}-{0:0}, at: __do_kmalloc_node mm/slub.c:5413 [inline]
ffffffff8ee8f980 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc_noprof+0xbc/0x720 mm/slub.c:5439

but task is already holding lock:
ffffffff8ebf9040 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0xa4f/0x1fe0 kernel/workqueue.c:5982

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #7 (wq_pool_mutex){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
       __alloc_workqueue+0xa4f/0x1fe0 kernel/workqueue.c:5982
       alloc_workqueue_va kernel/workqueue.c:6033 [inline]
       alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:6049
       padata_alloc+0xbe/0x360 kernel/padata.c:964
       pcrypt_init_padata+0x27/0x100 crypto/pcrypt.c:335
       pcrypt_init+0x60/0xc0 crypto/pcrypt.c:360
       do_one_initcall+0x250/0x870 init/main.c:1357
       do_initcall_level+0x10a/0x1a0 init/main.c:1419
       do_initcalls+0x59/0xa0 init/main.c:1435
       kernel_init_freeable+0x29d/0x3e0 init/main.c:1670
       kernel_init+0x22/0x1d0 init/main.c:1560
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #6 (cpu_hotplug_lock){++++}-{0:0}:
       percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
       percpu_down_read include/linux/percpu-rwsem.h:77 [inline]
       cpus_read_lock+0x42/0x160 kernel/cpu.c:490
       static_key_slow_inc+0x12/0x30 kernel/jump_label.c:190
       nbd_genl_reconnect_sock_cb+0x69a/0xbb0 drivers/block/nbd.c:1377
       nbd_genl_foreach_sock+0x265/0x450 drivers/block/nbd.c:2152
       nbd_genl_reconfigure+0xbbb/0x1040 drivers/block/nbd.c:2477
       genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
       genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
       genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
       netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
       netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
       netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1345
       netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
       sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
       __sock_sendmsg net/socket.c:815 [inline]
       ____sys_sendmsg+0x54e/0x850 net/socket.c:2713
       ___sys_sendmsg+0x2a5/0x360 net/socket.c:2767
       __sys_sendmsg net/socket.c:2799 [inline]
       __do_sys_sendmsg net/socket.c:2804 [inline]
       __se_sys_sendmsg net/socket.c:2802 [inline]
       __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #5 (&nsock->tx_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
       nbd_handle_cmd drivers/block/nbd.c:1143 [inline]
       nbd_queue_rq+0x373/0xff0 drivers/block/nbd.c:1207
       blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2117
       __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
       blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
       __blk_mq_sched_dispatch_requests+0xd36/0x1580 block/blk-mq-sched.c:307
       blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
       blk_mq_run_work_fn+0x16c/0x300 block/blk-mq.c:2532
       process_one_work kernel/workqueue.c:3396 [inline]
       process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
       worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
       kthread+0x38b/0x480 kernel/kthread.c:436
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #4 (&cmd->lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
       nbd_queue_rq+0xc1/0xff0 drivers/block/nbd.c:1199
       blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2117
       __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
       blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
       __blk_mq_sched_dispatch_requests+0xd36/0x1580 block/blk-mq-sched.c:307
       blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
       blk_mq_run_work_fn+0x16c/0x300 block/blk-mq.c:2532
       process_one_work kernel/workqueue.c:3396 [inline]
       process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
       worker_thread+0xa47/0xfb0 kernel/workqueue.c:3560
       kthread+0x38b/0x480 kernel/kthread.c:436
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #3 (set->srcu){.+.+}-{0:0}:
       srcu_lock_sync include/linux/srcu.h:210 [inline]
       __synchronize_srcu+0xc9/0x2f0 kernel/rcu/srcutree.c:1462
       elevator_switch+0x1e8/0x7b0 block/elevator.c:576
       elevator_change+0x2fa/0x480 block/elevator.c:681
       elevator_set_default+0x375/0x440 block/elevator.c:754
       blk_register_queue+0x3f3/0x4e0 block/blk-sysfs.c:992
       __add_disk+0x6cb/0xe30 block/genhd.c:524
       add_disk_fwnode+0x100/0x3a0 block/genhd.c:593
       add_disk include/linux/blkdev.h:798 [inline]
       nbd_dev_add+0x733/0xb60 drivers/block/nbd.c:2026
       nbd_init+0x168/0x1f0 drivers/block/nbd.c:2743
       do_one_initcall+0x250/0x870 init/main.c:1357
       do_initcall_level+0x10a/0x1a0 init/main.c:1419
       do_initcalls+0x59/0xa0 init/main.c:1435
       kernel_init_freeable+0x29d/0x3e0 init/main.c:1670
       kernel_init+0x22/0x1d0 init/main.c:1560
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #2 (&q->elevator_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x19d/0x1550 kernel/locking/mutex.c:821
       elevator_change+0x1af/0x480 block/elevator.c:679
       elevator_set_none+0xb5/0x140 block/elevator.c:769
       blk_mq_elv_switch_none block/blk-mq.c:5102 [inline]
       __blk_mq_update_nr_hw_queues block/blk-mq.c:5147 [inline]
       blk_mq_update_nr_hw_queues+0x5ef/0x19f0 block/blk-mq.c:5212
       nbd_start_device+0x189/0xb30 drivers/block/nbd.c:1530
       nbd_genl_connect+0x167d/0x1cd0 drivers/block/nbd.c:2310
       genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
       genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
       genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
       netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
       netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
       netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1345
       netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
       sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
       __sock_sendmsg net/socket.c:815 [inline]
       ____sys_sendmsg+0x54e/0x850 net/socket.c:2713
       ___sys_sendmsg+0x2a5/0x360 net/socket.c:2767
       __sys_sendmsg net/socket.c:2799 [inline]
       __do_sys_sendmsg net/socket.c:2804 [inline]
       __se_sys_sendmsg net/socket.c:2802 [inline]
       __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (&q->q_usage_counter(io)#49){++++}-{0:0}:
       blk_alloc_queue+0x544/0x690 block/blk-core.c:504
       blk_mq_alloc_queue block/blk-mq.c:4420 [inline]
       __blk_mq_alloc_disk+0x194/0x390 block/blk-mq.c:4467
       nbd_dev_add+0x494/0xb60 drivers/block/nbd.c:1996
       nbd_init+0x168/0x1f0 drivers/block/nbd.c:2743
       do_one_initcall+0x250/0x870 init/main.c:1357
       do_initcall_level+0x10a/0x1a0 init/main.c:1419
       do_initcalls+0x59/0xa0 init/main.c:1435
       kernel_init_freeable+0x29d/0x3e0 init/main.c:1670
       kernel_init+0x22/0x1d0 init/main.c:1560
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #0 (fs_reclaim){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3181 [inline]
       check_prevs_add kernel/locking/lockdep.c:3300 [inline]
       validate_chain kernel/locking/lockdep.c:3924 [inline]
       __lock_acquire+0x15ff/0x2e50 kernel/locking/lockdep.c:5254
       lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908
       __fs_reclaim_acquire mm/page_alloc.c:4375 [inline]
       fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4389
       might_alloc include/linux/sched/mm.h:316 [inline]
       slab_pre_alloc_hook mm/slub.c:4636 [inline]
       slab_alloc_node mm/slub.c:4974 [inline]
       __do_kmalloc_node mm/slub.c:5413 [inline]
       __kmalloc_noprof+0xbc/0x720 mm/slub.c:5439
       _kmalloc_noprof include/linux/slab.h:995 [inline]
       _kzalloc_noprof include/linux/slab.h:1312 [inline]
       apply_wqattrs_prepare+0xee/0xdc0 kernel/workqueue.c:5498
       apply_workqueue_attrs_locked kernel/workqueue.c:5584 [inline]
       alloc_and_link_pwqs kernel/workqueue.c:5731 [inline]
       __alloc_workqueue+0x11be/0x1fe0 kernel/workqueue.c:5984
       alloc_workqueue_va kernel/workqueue.c:6033 [inline]
       alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:6049
       ib_mad_port_open drivers/infiniband/core/mad.c:3282 [inline]
       ib_mad_init_device+0x993/0x2150 drivers/infiniband/core/mad.c:3369
       add_client_context+0x37c/0x7b0 drivers/infiniband/core/device.c:755
       enable_device_and_get+0x19c/0x3e0 drivers/infiniband/core/device.c:1375
       ib_register_device+0xdc8/0x1080 drivers/infiniband/core/device.c:1503
       rxe_register_device+0x1e3/0x350 drivers/infiniband/sw/rxe/rxe_verbs.c:1548
       rxe_net_add+0x81/0x110 drivers/infiniband/sw/rxe/rxe_net.c:625
       rxe_newlink+0xf4/0x1c0 drivers/infiniband/sw/rxe/rxe.c:243
       nldev_newlink+0x5be/0x650 drivers/infiniband/core/nldev.c:1858
       rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline]
       rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
       rdma_nl_rcv+0x6ef/0xa40 drivers/infiniband/core/netlink.c:259
       netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
       netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1345
       netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
       sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
       __sock_sendmsg net/socket.c:815 [inline]
       ____sys_sendmsg+0x54e/0x850 net/socket.c:2713
       ___sys_sendmsg+0x2a5/0x360 net/socket.c:2767
       __sys_sendmsg net/socket.c:2799 [inline]
       __do_sys_sendmsg net/socket.c:2804 [inline]
       __se_sys_sendmsg net/socket.c:2802 [inline]
       __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802
       do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
       do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
       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.4.2307/14243: 6, last CPU#0:
 #0: ffffffff9ad80a28 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:164 [inline]
 #0: ffffffff9ad80a28 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
 #0: ffffffff9ad80a28 (&rdma_nl_types[idx].sem){.+.+}-{4:4}, at: rdma_nl_rcv+0x33d/0xa40 drivers/infiniband/core/netlink.c:259
 #1: ffffffff8ffaca48 (link_ops_rwsem){++++}-{4:4}, at: nldev_newlink+0x42b/0x650 drivers/infiniband/core/nldev.c:1848
 #2: ffffffff8ff9db68 (devices_rwsem){++++}-{4:4}, at: enable_device_and_get+0xff/0x3e0 drivers/infiniband/core/device.c:1365
 #3: ffffffff8ff9de68 (clients_rwsem){++++}-{4:4}, at: enable_device_and_get+0x165/0x3e0 drivers/infiniband/core/device.c:1373
 #4: ffff888056f38658 (&device->client_data_rwsem){++++}-{4:4}, at: add_client_context+0x33e/0x7b0 drivers/infiniband/core/device.c:753
 #5: ffffffff8ebf9040 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0xa4f/0x1fe0 kernel/workqueue.c:5982

stack backtrace:
CPU: 0 UID: 0 PID: 14243 Comm: syz.4.2307 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2059
 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2191
 check_prev_add kernel/locking/lockdep.c:3181 [inline]
 check_prevs_add kernel/locking/lockdep.c:3300 [inline]
 validate_chain kernel/locking/lockdep.c:3924 [inline]
 __lock_acquire+0x15ff/0x2e50 kernel/locking/lockdep.c:5254
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5908
 __fs_reclaim_acquire mm/page_alloc.c:4375 [inline]
 fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4389
 might_alloc include/linux/sched/mm.h:316 [inline]
 slab_pre_alloc_hook mm/slub.c:4636 [inline]
 slab_alloc_node mm/slub.c:4974 [inline]
 __do_kmalloc_node mm/slub.c:5413 [inline]
 __kmalloc_noprof+0xbc/0x720 mm/slub.c:5439
 _kmalloc_noprof include/linux/slab.h:995 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 apply_wqattrs_prepare+0xee/0xdc0 kernel/workqueue.c:5498
 apply_workqueue_attrs_locked kernel/workqueue.c:5584 [inline]
 alloc_and_link_pwqs kernel/workqueue.c:5731 [inline]
 __alloc_workqueue+0x11be/0x1fe0 kernel/workqueue.c:5984
 alloc_workqueue_va kernel/workqueue.c:6033 [inline]
 alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:6049
 ib_mad_port_open drivers/infiniband/core/mad.c:3282 [inline]
 ib_mad_init_device+0x993/0x2150 drivers/infiniband/core/mad.c:3369
 add_client_context+0x37c/0x7b0 drivers/infiniband/core/device.c:755
 enable_device_and_get+0x19c/0x3e0 drivers/infiniband/core/device.c:1375
 ib_register_device+0xdc8/0x1080 drivers/infiniband/core/device.c:1503
 rxe_register_device+0x1e3/0x350 drivers/infiniband/sw/rxe/rxe_verbs.c:1548
 rxe_net_add+0x81/0x110 drivers/infiniband/sw/rxe/rxe_net.c:625
 rxe_newlink+0xf4/0x1c0 drivers/infiniband/sw/rxe/rxe.c:243
 nldev_newlink+0x5be/0x650 drivers/infiniband/core/nldev.c:1858
 rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline]
 rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
 rdma_nl_rcv+0x6ef/0xa40 drivers/infiniband/core/netlink.c:259
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800
 __sock_sendmsg net/socket.c:815 [inline]
 ____sys_sendmsg+0x54e/0x850 net/socket.c:2713
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2767
 __sys_sendmsg net/socket.c:2799 [inline]
 __do_sys_sendmsg net/socket.c:2804 [inline]
 __se_sys_sendmsg net/socket.c:2802 [inline]
 __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2802
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feedaf9e159
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:00007feedbdc1028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007feedb225fa0 RCX: 00007feedaf9e159
RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000005
RBP: 00007feedb03503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feedb226038 R14: 00007feedb225fa0 R15: 00007ffce4229458
 </TASK>
smbdirect: ib_dev[syz2]: 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[syz2]: 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[syz2]PORT[1]: iwarp=0 ib=0 roce=1 v1=0 v2=1 core_cap_flags=0x803005
RDS/IB: syz2: added
smc: adding ib device syz2 with port count 1
smc:    ib device syz2 port 1 has no pnetid
wg2 speed is unknown, defaulting to 1000
wg2 speed is unknown, defaulting to 1000
wg2 speed is unknown, defaulting to 1000
wg2 speed is unknown, defaulting to 1000
wg2 speed is unknown, defaulting to 1000