pimreg: left allmulticast mode
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.5007/26413 is trying to acquire lock:
ffffffff91277460 (xps_map_mutex){+.+.}-{4:4}, at: netif_reset_xps_queues net/core/dev.c:2842 [inline]
ffffffff91277460 (xps_map_mutex){+.+.}-{4:4}, at: netif_reset_xps_queues_gt+0x6f/0xc0 net/core/dev.c:2855

but task is already holding lock:
ffffffff8fbe5af0 (cpu_hotplug_lock){++++}-{0:0}, at: netif_reset_xps_queues net/core/dev.c:2841 [inline]
ffffffff8fbe5af0 (cpu_hotplug_lock){++++}-{0:0}, at: netif_reset_xps_queues_gt+0x61/0xc0 net/core/dev.c:2855

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #8 (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+0x3d/0x160 kernel/cpu.c:490
       static_key_slow_inc+0x12/0x30 kernel/jump_label.c:190
       udp_tunnel_encap_enable include/net/udp_tunnel.h:234 [inline]
       setup_udp_tunnel_sock+0x2eb/0x4f0 net/ipv4/udp_tunnel_core.c:90
       l2tp_tunnel_register+0xe77/0x1570 net/l2tp/l2tp_core.c:1690
       pppol2tp_tunnel_get net/l2tp/l2tp_ppp.c:663 [inline]
       pppol2tp_connect+0x8e3/0x18b0 net/l2tp/l2tp_ppp.c:711
       connect_socket net/socket.c:2143 [inline]
       __sys_connect_file net/socket.c:2168 [inline]
       __sys_connect+0x316/0x450 net/socket.c:2185
       __do_sys_connect net/socket.c:2191 [inline]
       __se_sys_connect net/socket.c:2188 [inline]
       __x64_sys_connect+0x7a/0x90 net/socket.c:2188
       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

-> #7 (sk_lock-AF_INET){+.+.}-{0:0}:
       lock_sock_nested+0x41/0x100 net/core/sock.c:3908
       lock_sock include/net/sock.h:1717 [inline]
       inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:910
       nbd_mark_nsock_dead+0x2cb/0x550 drivers/block/nbd.c:319
       recv_work+0x1cee/0x1e10 drivers/block/nbd.c:1030
       process_one_work kernel/workqueue.c:3495 [inline]
       process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
       worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
       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

-> #6 (&nsock->tx_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x197/0x15a0 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:2130
       __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+0x167/0x2f0 block/blk-mq.c:2545
       process_one_work kernel/workqueue.c:3495 [inline]
       process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
       worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
       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

-> #5 (&cmd->lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x197/0x15a0 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:2130
       __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+0x167/0x2f0 block/blk-mq.c:2545
       process_one_work kernel/workqueue.c:3495 [inline]
       process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
       worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
       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 (set->srcu){.+.+}-{0:0}:
       srcu_lock_sync include/linux/srcu.h:225 [inline]
       __synchronize_srcu+0xca/0x2f0 kernel/rcu/srcutree.c:1662
       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+0x6b8/0xdb0 block/genhd.c:531
       add_disk_fwnode+0x100/0x3a0 block/genhd.c:600
       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:1362
       do_initcall_level+0x10a/0x1a0 init/main.c:1424
       do_initcalls+0x59/0xa0 init/main.c:1440
       kernel_init_freeable+0x29d/0x3e0 init/main.c:1675
       kernel_init+0x22/0x1d0 init/main.c:1565
       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 (&q->elevator_lock){+.+.}-{4:4}:
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x197/0x15a0 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:5113 [inline]
       __blk_mq_update_nr_hw_queues block/blk-mq.c:5158 [inline]
       blk_mq_update_nr_hw_queues+0x5ef/0x19f0 block/blk-mq.c:5223
       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:2576
       genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
       netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
       netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361
       netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920
       sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800
       __sock_sendmsg net/socket.c:818 [inline]
       ____sys_sendmsg+0x54e/0x850 net/socket.c:2715
       ___sys_sendmsg+0x2a5/0x360 net/socket.c:2769
       __sys_sendmsg net/socket.c:2801 [inline]
       __do_sys_sendmsg net/socket.c:2806 [inline]
       __se_sys_sendmsg net/socket.c:2804 [inline]
       __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804
       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

-> #2 (&q->q_usage_counter(io)#50){++++}-{0:0}:
       blk_alloc_queue+0x544/0x690 block/blk-core.c:504
       blk_mq_alloc_queue block/blk-mq.c:4431 [inline]
       __blk_mq_alloc_disk+0x194/0x390 block/blk-mq.c:4478
       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:1362
       do_initcall_level+0x10a/0x1a0 init/main.c:1424
       do_initcalls+0x59/0xa0 init/main.c:1440
       kernel_init_freeable+0x29d/0x3e0 init/main.c:1675
       kernel_init+0x22/0x1d0 init/main.c:1565
       ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #1 (fs_reclaim){+.+.}-{0:0}:
       __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/0x710 mm/slub.c:5439
       _kmalloc_noprof include/linux/slab.h:995 [inline]
       _kzalloc_noprof include/linux/slab.h:1312 [inline]
       __netif_set_xps_queue+0x509/0x1e50 net/core/dev.c:2975
       virtnet_set_affinity+0x586/0x6c0 drivers/net/virtio_net.c:4037
       init_vqs+0x1085/0x11c0 drivers/net/virtio_net.c:6603
       virtnet_probe+0x219b/0x4840 drivers/net/virtio_net.c:7004
       virtio_dev_probe+0xdec/0x10b0 drivers/virtio/virtio.c:347
       call_driver_probe drivers/base/dd.c:-1 [inline]
       really_probe+0x254/0xae0 drivers/base/dd.c:706
       __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
       driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
       __driver_attach+0x339/0x600 drivers/base/dd.c:1292
       bus_for_each_dev+0x23b/0x2c0 drivers/base/bus.c:386
       bus_add_driver+0x38f/0x6e0 drivers/base/bus.c:771
       driver_register+0x23a/0x320 drivers/base/driver.c:174
       virtio_net_driver_init+0x71/0xa0 drivers/net/virtio_net.c:7328
       do_one_initcall+0x250/0x870 init/main.c:1362
       do_initcall_level+0x10a/0x1a0 init/main.c:1424
       do_initcalls+0x59/0xa0 init/main.c:1440
       kernel_init_freeable+0x29d/0x3e0 init/main.c:1675
       kernel_init+0x22/0x1d0 init/main.c:1565
       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 (xps_map_mutex){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3209 [inline]
       check_prevs_add kernel/locking/lockdep.c:3328 [inline]
       validate_chain kernel/locking/lockdep.c:3952 [inline]
       __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
       lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
       __mutex_lock_common kernel/locking/mutex.c:646 [inline]
       __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821
       netif_reset_xps_queues net/core/dev.c:2842 [inline]
       netif_reset_xps_queues_gt+0x6f/0xc0 net/core/dev.c:2855
       unregister_netdevice_many_notify+0x1824/0x1d80 net/core/dev.c:12733
       mrtsock_destruct+0x2ce/0x320 net/ipv4/ipmr.c:1405
       ip_ra_control+0x492/0x530 net/ipv4/ip_sockglue.c:374
       raw_close+0x19/0x30 net/ipv4/raw.c:695
       inet_release+0x143/0x190 net/ipv4/af_inet.c:442
       __sock_release+0xa0/0x1f0 net/socket.c:735
       sock_close+0x1c/0x30 net/socket.c:1529
       __fput+0x408/0xa40 fs/file_table.c:512
       fput_close_sync+0x11f/0x240 fs/file_table.c:618
       filp_close_sync fs/open.c:1573 [inline]
       __do_sys_close fs/open.c:1596 [inline]
       __se_sys_close+0xa2/0x160 fs/open.c:1583
       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:
  xps_map_mutex --> sk_lock-AF_INET --> cpu_hotplug_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(cpu_hotplug_lock);
                               lock(sk_lock-AF_INET);
                               lock(cpu_hotplug_lock);
  lock(xps_map_mutex);

 *** DEADLOCK ***

locks held by syz.1.5007/26413: 3, last CPU#1:
 #0: ffff888067ea52c0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1024 [inline]
 #0: ffff888067ea52c0 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release+0x7a/0x1f0 net/socket.c:734
 #1: ffffffff91281be0 (rtnl_mutex){+.+.}-{4:4}, at: mrtsock_destruct+0xeb/0x320 net/ipv4/ipmr.c:1390
 #2: ffffffff8fbe5af0 (cpu_hotplug_lock){++++}-{0:0}, at: netif_reset_xps_queues net/core/dev.c:2841 [inline]
 #2: ffffffff8fbe5af0 (cpu_hotplug_lock){++++}-{0:0}, at: netif_reset_xps_queues_gt+0x61/0xc0 net/core/dev.c:2855

stack backtrace:
CPU: 1 UID: 0 PID: 26413 Comm: syz.1.5007 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087
 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219
 check_prev_add kernel/locking/lockdep.c:3209 [inline]
 check_prevs_add kernel/locking/lockdep.c:3328 [inline]
 validate_chain kernel/locking/lockdep.c:3952 [inline]
 __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288
 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942
 __mutex_lock_common kernel/locking/mutex.c:646 [inline]
 __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821
 netif_reset_xps_queues net/core/dev.c:2842 [inline]
 netif_reset_xps_queues_gt+0x6f/0xc0 net/core/dev.c:2855
 unregister_netdevice_many_notify+0x1824/0x1d80 net/core/dev.c:12733
 mrtsock_destruct+0x2ce/0x320 net/ipv4/ipmr.c:1405
 ip_ra_control+0x492/0x530 net/ipv4/ip_sockglue.c:374
 raw_close+0x19/0x30 net/ipv4/raw.c:695
 inet_release+0x143/0x190 net/ipv4/af_inet.c:442
 __sock_release+0xa0/0x1f0 net/socket.c:735
 sock_close+0x1c/0x30 net/socket.c:1529
 __fput+0x408/0xa40 fs/file_table.c:512
 fput_close_sync+0x11f/0x240 fs/file_table.c:618
 filp_close_sync fs/open.c:1573 [inline]
 __do_sys_close fs/open.c:1596 [inline]
 __se_sys_close+0xa2/0x160 fs/open.c:1583
 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: 0033:0x7f4fae79f559
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:00007f4faf5ef028 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007f4faea26090 RCX: 00007f4fae79f559
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f4fae836b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4faea26128 R14: 00007f4faea26090 R15: 00007fff1fe21df8
 </TASK>