====================================================== WARNING: possible circular locking dependency detected 4.19.211-syzkaller #0 Not tainted ------------------------------------------------------ systemd-udevd/17626 is trying to acquire lock: 00000000314f4f9c ((wq_completion)"knbd%d-recv"nbd->index){+.+.}, at: flush_workqueue+0xe8/0x13e0 kernel/workqueue.c:2658 but task is already holding lock: 000000003289c8bf (&nbd->config_lock){+.+.}, at: refcount_dec_and_mutex_lock lib/refcount.c:311 [inline] 000000003289c8bf (&nbd->config_lock){+.+.}, at: refcount_dec_and_mutex_lock+0x4a/0x80 lib/refcount.c:306 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #8 (&nbd->config_lock){+.+.}: nbd_open+0x2e2/0x6f0 drivers/block/nbd.c:1428 __blkdev_get+0x372/0x1480 fs/block_dev.c:1494 blkdev_get+0xb0/0x940 fs/block_dev.c:1627 blkdev_open+0x202/0x290 fs/block_dev.c:1788 do_dentry_open+0x4aa/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x793/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #7 (nbd_index_mutex){+.+.}: nbd_open+0x73/0x6f0 drivers/block/nbd.c:1415 __blkdev_get+0x372/0x1480 fs/block_dev.c:1494 blkdev_get+0xb0/0x940 fs/block_dev.c:1627 blkdev_open+0x202/0x290 fs/block_dev.c:1788 do_dentry_open+0x4aa/0x1160 fs/open.c:796 do_last fs/namei.c:3421 [inline] path_openat+0x793/0x2df0 fs/namei.c:3537 do_filp_open+0x18c/0x3f0 fs/namei.c:3567 do_sys_open+0x3b3/0x520 fs/open.c:1085 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #6 (&bdev->bd_mutex){+.+.}: blkdev_put+0x30/0x520 fs/block_dev.c:1839 btrfs_close_bdev fs/btrfs/volumes.c:1033 [inline] btrfs_close_one_device fs/btrfs/volumes.c:1057 [inline] close_fs_devices.part.0+0x24d/0x8e0 fs/btrfs/volumes.c:1085 close_fs_devices fs/btrfs/volumes.c:1117 [inline] btrfs_close_devices+0x95/0x1f0 fs/btrfs/volumes.c:1103 close_ctree+0x3c8/0x850 fs/btrfs/disk-io.c:4047 generic_shutdown_super+0x144/0x370 fs/super.c:456 kill_anon_super+0x36/0x60 fs/super.c:1032 btrfs_kill_super+0x49/0x550 fs/btrfs/super.c:2221 deactivate_locked_super+0x94/0x160 fs/super.c:329 deactivate_super+0x174/0x1a0 fs/super.c:360 cleanup_mnt+0x1a8/0x290 fs/namespace.c:1098 task_work_run+0x148/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #5 (&fs_devs->device_list_mutex){+.+.}: btrfs_finish_chunk_alloc+0x27b/0xf90 fs/btrfs/volumes.c:4938 btrfs_create_pending_block_groups+0x242/0x590 fs/btrfs/extent-tree.c:10134 __btrfs_end_transaction+0x21a/0xb00 fs/btrfs/transaction.c:855 flush_space+0xa41/0xee0 fs/btrfs/extent-tree.c:4861 btrfs_async_reclaim_metadata_space+0x466/0x1050 fs/btrfs/extent-tree.c:4977 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 -> #4 (sb_internal#2){.+.+}: sb_start_intwrite include/linux/fs.h:1626 [inline] start_transaction+0xa37/0xf90 fs/btrfs/transaction.c:528 btrfs_dirty_inode+0xe3/0x210 fs/btrfs/inode.c:6165 btrfs_update_time+0x33b/0x3d0 fs/btrfs/inode.c:6207 update_time fs/inode.c:1675 [inline] touch_atime+0x23c/0x2a0 fs/inode.c:1746 file_accessed include/linux/fs.h:2123 [inline] btrfs_file_mmap+0x11b/0x160 fs/btrfs/file.c:2274 call_mmap include/linux/fs.h:1826 [inline] mmap_region+0xc94/0x16b0 mm/mmap.c:1757 do_mmap+0x8e8/0x1080 mm/mmap.c:1530 do_mmap_pgoff include/linux/mm.h:2329 [inline] vm_mmap_pgoff+0x197/0x200 mm/util.c:357 ksys_mmap_pgoff+0x298/0x5a0 mm/mmap.c:1580 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #3 (&mm->mmap_sem){++++}: _copy_from_iter_full+0x256/0x7c0 lib/iov_iter.c:723 copy_from_iter_full include/linux/uio.h:124 [inline] skb_do_copy_data_nocache include/net/sock.h:1971 [inline] skb_add_data_nocache include/net/sock.h:1982 [inline] tcp_sendmsg_locked+0x194d/0x2f60 net/ipv4/tcp.c:1339 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1462 inet_sendmsg+0x132/0x5a0 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:661 sock_write_iter+0x287/0x3c0 net/socket.c:966 call_write_iter include/linux/fs.h:1821 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x51b/0x770 fs/read_write.c:487 vfs_write+0x1f3/0x540 fs/read_write.c:549 ksys_write+0x12b/0x2a0 fs/read_write.c:599 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (sk_lock-AF_INET){+.+.}: lock_sock include/net/sock.h:1512 [inline] sctp_recvmsg+0xa3/0xae0 net/sctp/socket.c:2222 inet_recvmsg+0x124/0x5c0 net/ipv4/af_inet.c:830 sock_recvmsg_nosec net/socket.c:859 [inline] sock_recvmsg net/socket.c:866 [inline] sock_recvmsg+0xca/0x110 net/socket.c:862 sock_xmit+0x37d/0x5c0 drivers/block/nbd.c:439 nbd_read_stat drivers/block/nbd.c:633 [inline] recv_work+0x1e9/0x1100 drivers/block/nbd.c:732 process_one_work+0x864/0x1570 kernel/workqueue.c:2153 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 -> #1 ((work_completion)(&args->work)){+.+.}: worker_thread+0x64c/0x1130 kernel/workqueue.c:2296 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 -> #0 ((wq_completion)"knbd%d-recv"nbd->index){+.+.}: flush_workqueue+0x117/0x13e0 kernel/workqueue.c:2661 drain_workqueue+0x1a5/0x460 kernel/workqueue.c:2826 destroy_workqueue+0x75/0x790 kernel/workqueue.c:4183 nbd_config_put+0x3c5/0x870 drivers/block/nbd.c:1175 nbd_release+0xf4/0x170 drivers/block/nbd.c:1461 __blkdev_put+0x636/0x870 fs/block_dev.c:1819 blkdev_close+0x86/0xb0 fs/block_dev.c:1888 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: (wq_completion)"knbd%d-recv"nbd->index --> nbd_index_mutex --> &nbd->config_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&nbd->config_lock); lock(nbd_index_mutex); lock(&nbd->config_lock); lock((wq_completion)"knbd%d-recv"nbd->index); *** DEADLOCK *** 2 locks held by systemd-udevd/17626: #0: 00000000a743ef1b (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0xfc/0x870 fs/block_dev.c:1806 #1: 000000003289c8bf (&nbd->config_lock){+.+.}, at: refcount_dec_and_mutex_lock lib/refcount.c:311 [inline] #1: 000000003289c8bf (&nbd->config_lock){+.+.}, at: refcount_dec_and_mutex_lock+0x4a/0x80 lib/refcount.c:306 stack backtrace: CPU: 1 PID: 17626 Comm: systemd-udevd Not tainted 4.19.211-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2ef lib/dump_stack.c:118 print_circular_bug.constprop.0.cold+0x2d7/0x41e kernel/locking/lockdep.c:1222 check_prev_add kernel/locking/lockdep.c:1866 [inline] check_prevs_add kernel/locking/lockdep.c:1979 [inline] validate_chain kernel/locking/lockdep.c:2420 [inline] __lock_acquire+0x30c9/0x3ff0 kernel/locking/lockdep.c:3416 lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3908 flush_workqueue+0x117/0x13e0 kernel/workqueue.c:2661 drain_workqueue+0x1a5/0x460 kernel/workqueue.c:2826 destroy_workqueue+0x75/0x790 kernel/workqueue.c:4183 nbd_config_put+0x3c5/0x870 drivers/block/nbd.c:1175 nbd_release+0xf4/0x170 drivers/block/nbd.c:1461 __blkdev_put+0x636/0x870 fs/block_dev.c:1819 blkdev_close+0x86/0xb0 fs/block_dev.c:1888 __fput+0x2ce/0x890 fs/file_table.c:278 task_work_run+0x148/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:271 [inline] do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7ff93fcce270 Code: 73 01 c3 48 8b 0d 38 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 59 c1 20 00 00 75 10 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ee fb ff ff 48 89 04 24 RSP: 002b:00007ffdc3abd5b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00007ff93fcce270 RDX: 000000000aba9500 RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007ff940b88710 R08: 00005589d4108ea0 R09: 0000000000000008 R10: 00005589d4108c98 R11: 0000000000000246 R12: 0000000000000000 R13: 00005589d40f8120 R14: 0000000000000003 R15: 000000000000000e netlink: 16 bytes leftover after parsing attributes in process `syz-executor.4'. BTRFS info (device loop5): using free space tree BTRFS info (device loop5): has skinny extents 9pnet_virtio: no channels available for device 127.0.0.1 ieee80211 phy18: Selected rate control algorithm 'minstrel_ht' BTRFS info (device loop5): using free space tree overlayfs: unrecognized mount option "uus" or missing value BTRFS info (device loop5): has skinny extents ieee80211 phy19: Selected rate control algorithm 'minstrel_ht' 9pnet_virtio: no channels available for device 127.0.0.1 overlayfs: unrecognized mount option "uus" or missing value ieee80211 phy20: Selected rate control algorithm 'minstrel_ht' 9pnet_virtio: no channels available for device 127.0.0.1 ieee80211 phy21: Selected rate control algorithm 'minstrel_ht' ieee80211 phy22: Selected rate control algorithm 'minstrel_ht' 9pnet_virtio: no channels available for device 127.0.0.1 BTRFS info (device loop5): using free space tree BTRFS info (device loop5): has skinny extents overlayfs: unrecognized mount option "uus" or missing value ieee802154 phy0 wpan0: encryption failed: -22 ieee802154 phy1 wpan1: encryption failed: -22 ieee80211 phy23: Selected rate control algorithm 'minstrel_ht' 9pnet_virtio: no channels available for device 127.0.0.1 audit: type=1804 audit(1678148981.657:286): pid=18043 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir2263290494/syzkaller.z436tm/155/bus" dev="sda1" ino=14587 res=1 audit: type=1800 audit(1678148981.657:287): pid=18043 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.2" name="bus" dev="sda1" ino=14587 res=0 ieee80211 phy24: Selected rate control algorithm 'minstrel_ht' 9pnet_virtio: no channels available for device 127.0.0.1 ieee80211 phy25: Selected rate control algorithm 'minstrel_ht' ieee80211 phy26: Selected rate control algorithm 'minstrel_ht' overlayfs: filesystem on './bus' not supported as upperdir 9pnet_virtio: no channels available for device 127.0.0.1 overlayfs: filesystem on './bus' not supported as upperdir overlayfs: failed to resolve './bus': -2 ieee80211 phy27: Selected rate control algorithm 'minstrel_ht' ieee80211 phy28: Selected rate control algorithm 'minstrel_ht' ieee80211 phy29: Selected rate control algorithm 'minstrel_ht' ieee80211 phy30: Selected rate control algorithm 'minstrel_ht' ieee80211 phy31: Selected rate control algorithm 'minstrel_ht' audit: type=1804 audit(1678148983.008:288): pid=18226 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.2" name="/root/syzkaller-testdir2263290494/syzkaller.z436tm/157/bus" dev="sda1" ino=14419 res=1 audit: type=1800 audit(1678148983.008:289): pid=18226 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=collect_data cause=failed(directio) comm="syz-executor.2" name="bus" dev="sda1" ino=14419 res=0 9pnet_virtio: no channels available for device 127.0.0.1 ieee80211 phy32: Selected rate control algorithm 'minstrel_ht' ieee80211 phy33: Selected rate control algorithm 'minstrel_ht' ieee80211 phy34: Selected rate control algorithm 'minstrel_ht' ieee80211 phy35: Selected rate control algorithm 'minstrel_ht' ieee80211 phy36: Selected rate control algorithm 'minstrel_ht' ieee80211 phy37: Selected rate control algorithm 'minstrel_ht' ieee80211 phy38: Selected rate control algorithm 'minstrel_ht' ieee80211 phy39: Selected rate control algorithm 'minstrel_ht' 9pnet_virtio: no channels available for device 127.0.0.1 ieee80211 phy40: Selected rate control algorithm 'minstrel_ht' ieee80211 phy41: Selected rate control algorithm 'minstrel_ht' ieee80211 phy42: Selected rate control algorithm 'minstrel_ht' ieee80211 phy43: Selected rate control algorithm 'minstrel_ht' ieee80211 phy44: Selected rate control algorithm 'minstrel_ht' ieee80211 phy45: Selected rate control algorithm 'minstrel_ht' ieee80211 phy46: Selected rate control algorithm 'minstrel_ht' 9pnet_virtio: no channels available for device 127.0.0.1 ieee80211 phy47: Selected rate control algorithm 'minstrel_ht' ieee80211 phy48: Selected rate control algorithm 'minstrel_ht' ieee80211 phy49: Selected rate control algorithm 'minstrel_ht' 9pnet_virtio: no channels available for device 127.0.0.1 ieee80211 phy50: Selected rate control algorithm 'minstrel_ht' ieee80211 phy51: Selected rate control algorithm 'minstrel_ht' ieee80211 phy52: Selected rate control algorithm 'minstrel_ht' ieee80211 phy53: Selected rate control algorithm 'minstrel_ht' ieee80211 phy54: Selected rate control algorithm 'minstrel_ht' ieee80211 phy55: Selected rate control algorithm 'minstrel_ht' ieee80211 phy56: Selected rate control algorithm 'minstrel_ht' ieee80211 phy57: Selected rate control algorithm 'minstrel_ht' ieee80211 phy58: Selected rate control algorithm 'minstrel_ht' 9pnet_virtio: no channels available for device 127.0.0.1 audit: type=1804 audit(1678148985.708:290): pid=18572 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/143/bus" dev="sda1" ino=13909 res=1 audit: type=1804 audit(1678148985.708:291): pid=18572 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/143/bus" dev="sda1" ino=13909 res=1 9pnet_virtio: no channels available for device 127.0.0.1 ieee80211 phy59: Selected rate control algorithm 'minstrel_ht' 9pnet_virtio: no channels available for device 127.0.0.1 ieee80211 phy60: Selected rate control algorithm 'minstrel_ht' ieee80211 phy61: Selected rate control algorithm 'minstrel_ht' ieee80211 phy62: Selected rate control algorithm 'minstrel_ht' ieee80211 phy63: Selected rate control algorithm 'minstrel_ht' ieee80211 phy64: Selected rate control algorithm 'minstrel_ht' audit: type=1804 audit(1678148986.628:292): pid=18664 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/144/bus" dev="sda1" ino=14643 res=1 audit: type=1804 audit(1678148986.628:293): pid=18664 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/144/bus" dev="sda1" ino=14643 res=1 audit: type=1804 audit(1678148986.628:294): pid=18664 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/144/bus" dev="sda1" ino=14643 res=1 audit: type=1804 audit(1678148986.628:295): pid=18664 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/144/bus" dev="sda1" ino=14643 res=1 audit: type=1804 audit(1678148986.628:296): pid=18664 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/144/bus" dev="sda1" ino=14643 res=1 audit: type=1804 audit(1678148986.628:297): pid=18664 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/144/bus" dev="sda1" ino=14643 res=1 audit: type=1804 audit(1678148986.628:298): pid=18664 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/144/bus" dev="sda1" ino=14643 res=1 audit: type=1804 audit(1678148986.628:299): pid=18664 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/144/bus" dev="sda1" ino=14643 res=1 audit: type=1804 audit(1678148986.628:300): pid=18664 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/144/bus" dev="sda1" ino=14643 res=1 audit: type=1804 audit(1678148986.628:301): pid=18664 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/144/bus" dev="sda1" ino=14643 res=1 audit: type=1804 audit(1678148986.628:302): pid=18664 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/144/bus" dev="sda1" ino=14643 res=1 audit: type=1804 audit(1678148986.628:303): pid=18664 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/144/bus" dev="sda1" ino=14643 res=1 audit: type=1804 audit(1678148986.628:304): pid=18664 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir631943098/syzkaller.UOMBgt/144/bus" dev="sda1" ino=14643 res=1 ieee80211 phy65: Selected rate control algorithm 'minstrel_ht' ieee80211 phy66: Selected rate control algorithm 'minstrel_ht' ieee80211 phy67: Selected rate control algorithm 'minstrel_ht' ieee80211 phy68: Selected rate control algorithm 'minstrel_ht' ieee80211 phy69: Selected rate control algorithm 'minstrel_ht' ieee80211 phy70: Selected rate control algorithm 'minstrel_ht' 9pnet_virtio: no channels available for device 127.0.0.1