======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/u8:19/22262 is trying to acquire lock:
ffff88801be8d210 (&root->kernfs_iattr_rwsem){++++}-{4:4}, at: kernfs_unlink_sibling+0x71/0x180 fs/kernfs/dir.c:441
but task is already holding lock:
ffff88801be8d180 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_rename_ns+0x76/0x830 fs/kernfs/dir.c:1833
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #9 (&root->kernfs_rwsem){++++}-{4:4}:
down_write+0x96/0x200 kernel/locking/rwsem.c:1625
kernfs_add_one+0x41/0x5c0 fs/kernfs/dir.c:826
kernfs_create_dir_ns+0xde/0x130 fs/kernfs/dir.c:1131
internal_create_group+0x425/0x1180 fs/sysfs/group.c:176
cpuhp_invoke_callback+0x445/0x860 kernel/cpu.c:194
cpuhp_issue_call+0x430/0x7a0 kernel/cpu.c:-1
__cpuhp_setup_state_cpuslocked+0x3d9/0x6b0 kernel/cpu.c:2507
__cpuhp_setup_state+0x3f/0x60 kernel/cpu.c:2536
do_one_initcall+0x250/0x870 init/main.c:1392
do_initcall_level+0x104/0x190 init/main.c:1454
do_initcalls+0x59/0xa0 init/main.c:1470
kernel_init_freeable+0x2a6/0x3e0 init/main.c:1703
kernel_init+0x1d/0x1d0 init/main.c:1593
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
-> #8 (cpuhp_state_mutex){+.+.}-{4:4}:
-> #7 (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_reconnect_socket drivers/block/nbd.c:1342 [inline]
nbd_genl_reconfigure+0x132f/0x1ea0 drivers/block/nbd.c:2431
genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2551
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1895
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
__sys_sendmsg net/socket.c:2784 [inline]
__do_sys_sendmsg net/socket.c:2789 [inline]
__se_sys_sendmsg net/socket.c:2787 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #6 (&nsock->tx_lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820
nbd_handle_cmd drivers/block/nbd.c:1143 [inline]
nbd_queue_rq+0x37b/0x1100 drivers/block/nbd.c:1207
blk_mq_dispatch_rq_list+0xa70/0x1910 block/blk-mq.c:2148
__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+0xdcc/0x1600 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2386
blk_mq_dispatch_list+0xd16/0xe10 include/linux/spinlock.h:-1
blk_mq_flush_plug_list+0x48d/0x570 block/blk-mq.c:2997
__blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1230
blk_finish_plug block/blk-core.c:1257 [inline]
__submit_bio+0x28d/0x580 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:753
submit_bh fs/buffer.c:2742 [inline]
block_read_full_folio+0x599/0x830 fs/buffer.c:2344
filemap_read_folio+0x137/0x3b0 mm/filemap.c:2502
do_read_cache_folio+0x358/0x590 mm/filemap.c:4107
read_mapping_folio include/linux/pagemap.h:1017 [inline]
read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
adfspart_check_ICS+0xb1/0x960 block/partitions/acorn.c:356
check_partition block/partitions/core.c:143 [inline]
blk_add_partitions block/partitions/core.c:591 [inline]
bdev_disk_changed+0x817/0x1770 block/partitions/core.c:695
blkdev_get_whole+0x380/0x510 block/bdev.c:756
bdev_open+0x31e/0xd30 block/bdev.c:965
blkdev_open+0x470/0x610 block/fops.c:697
do_dentry_open+0x785/0x14e0 fs/open.c:947
vfs_open+0x3b/0x340 fs/open.c:1079
do_open fs/namei.c:4699 [inline]
path_openat+0x2e08/0x3860 fs/namei.c:4858
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #5 (&cmd->lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:646 [inline]
__mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820
nbd_queue_rq+0xc6/0x1100 drivers/block/nbd.c:1199
blk_mq_dispatch_rq_list+0xa70/0x1910 block/blk-mq.c:2148
__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+0xdcc/0x1600 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2386
blk_mq_dispatch_list+0xd16/0xe10 include/linux/spinlock.h:-1
blk_mq_flush_plug_list+0x48d/0x570 block/blk-mq.c:2997
__blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1230
blk_finish_plug block/blk-core.c:1257 [inline]
__submit_bio+0x28d/0x580 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:753
submit_bh fs/buffer.c:2742 [inline]
block_read_full_folio+0x599/0x830 fs/buffer.c:2344
filemap_read_folio+0x137/0x3b0 mm/filemap.c:2502
do_read_cache_folio+0x358/0x590 mm/filemap.c:4107
read_mapping_folio include/linux/pagemap.h:1017 [inline]
read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
adfspart_check_ICS+0xb1/0x960 block/partitions/acorn.c:356
check_partition block/partitions/core.c:143 [inline]
blk_add_partitions block/partitions/core.c:591 [inline]
bdev_disk_changed+0x817/0x1770 block/partitions/core.c:695
blkdev_get_whole+0x380/0x510 block/bdev.c:756
bdev_open+0x31e/0xd30 block/bdev.c:965
blkdev_open+0x470/0x610 block/fops.c:697
do_dentry_open+0x785/0x14e0 fs/open.c:947
vfs_open+0x3b/0x340 fs/open.c:1079
do_open fs/namei.c:4699 [inline]
path_openat+0x2e08/0x3860 fs/namei.c:4858
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #4 (set->srcu){.+.+}-{0:0}:
srcu_lock_sync include/linux/srcu.h:199 [inline]
__synchronize_srcu+0xca/0x300 kernel/rcu/srcutree.c:1481
elevator_switch+0x1e8/0x7a0 block/elevator.c:576
elevator_change+0x2cc/0x450 block/elevator.c:681
elevator_set_default+0x36c/0x430 block/elevator.c:754
blk_register_queue+0x3e9/0x4e0 block/blk-sysfs.c:987
__add_disk+0x677/0xd50 block/genhd.c:528
add_disk_fwnode+0xfb/0x480 block/genhd.c:597
add_disk include/linux/blkdev.h:794 [inline]
nbd_dev_add+0x72c/0xb50 drivers/block/nbd.c:1984
nbd_init+0x168/0x1f0 drivers/block/nbd.c:2692
do_one_initcall+0x250/0x870 init/main.c:1392
do_initcall_level+0x104/0x190 init/main.c:1454
do_initcalls+0x59/0xa0 init/main.c:1470
kernel_init_freeable+0x2a6/0x3e0 init/main.c:1703
kernel_init+0x1d/0x1d0 init/main.c:1593
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+0x1a3/0x1550 kernel/locking/mutex.c:820
elevator_change+0x1b3/0x450 block/elevator.c:679
elevator_set_none+0xb5/0x140 block/elevator.c:769
blk_mq_elv_switch_none block/blk-mq.c:5150 [inline]
__blk_mq_update_nr_hw_queues block/blk-mq.c:5195 [inline]
blk_mq_update_nr_hw_queues+0x5e7/0x1a60 block/blk-mq.c:5260
nbd_start_device+0x17f/0xb10 drivers/block/nbd.c:1489
nbd_genl_connect+0x165b/0x1cf0 drivers/block/nbd.c:2239
genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2551
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1895
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
__sys_sendmsg net/socket.c:2784 [inline]
__do_sys_sendmsg net/socket.c:2789 [inline]
__se_sys_sendmsg net/socket.c:2787 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #2 (&q->q_usage_counter(io)#50){++++}-{0:0}:
blk_alloc_queue+0x546/0x680 block/blk-core.c:461
blk_mq_alloc_queue block/blk-mq.c:4469 [inline]
__blk_mq_alloc_disk+0x197/0x390 block/blk-mq.c:4516
nbd_dev_add+0x499/0xb50 drivers/block/nbd.c:1954
nbd_init+0x168/0x1f0 drivers/block/nbd.c:2692
do_one_initcall+0x250/0x870 init/main.c:1392
do_initcall_level+0x104/0x190 init/main.c:1454
do_initcalls+0x59/0xa0 init/main.c:1470
kernel_init_freeable+0x2a6/0x3e0 init/main.c:1703
kernel_init+0x1d/0x1d0 init/main.c:1593
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:4325 [inline]
fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4339
might_alloc include/linux/sched/mm.h:317 [inline]
slab_pre_alloc_hook mm/slub.c:4520 [inline]
slab_alloc_node mm/slub.c:4875 [inline]
kmem_cache_alloc_noprof+0x40/0x650 mm/slub.c:4905
__kernfs_iattrs+0xdf/0x320 fs/kernfs/inode.c:36
kernfs_iattrs fs/kernfs/inode.c:59 [inline]
__kernfs_setattr fs/kernfs/inode.c:72 [inline]
kernfs_iop_setattr+0xea/0x3f0 fs/kernfs/inode.c:126
notify_change+0xc1a/0xf40 fs/attr.c:556
do_truncate+0x1c2/0x250 fs/open.c:68
handle_truncate fs/namei.c:4307 [inline]
do_open fs/namei.c:4703 [inline]
path_openat+0x2f89/0x3860 fs/namei.c:4858
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&root->kernfs_iattr_rwsem){++++}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
down_write+0x96/0x200 kernel/locking/rwsem.c:1625
kernfs_unlink_sibling+0x71/0x180 fs/kernfs/dir.c:441
kernfs_rename_ns+0x4a6/0x830 fs/kernfs/dir.c:1873
sysfs_rename_link_ns+0x16e/0x1b0 fs/sysfs/symlink.c:193
device_rename+0x110/0x210 drivers/base/core.c:4558
__dev_change_net_namespace+0x15d3/0x20a0 net/core/dev.c:12673
cfg80211_switch_netns+0x106/0x5a0 net/wireless/core.c:169
cfg80211_pernet_exit+0x92/0x120 net/wireless/core.c:1868
ops_exit_list net/core/net_namespace.c:199 [inline]
ops_undo_list+0x49f/0x940 net/core/net_namespace.c:252
cleanup_net+0x56b/0x800 net/core/net_namespace.c:702
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
kthread+0x389/0x470 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
other info that might help us debug this:
Chain exists of:
&root->kernfs_iattr_rwsem --> cpuhp_state_mutex --> &root->kernfs_rwsem
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&root->kernfs_rwsem);
lock(cpuhp_state_mutex);
lock(&root->kernfs_rwsem);
lock(&root->kernfs_iattr_rwsem);
*** DEADLOCK ***
5 locks held by kworker/u8:19/22262:
#0: ffff88801be8e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801be8e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90003597c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90003597c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8fdc36e8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
#3: ffffffff8fdd2400 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_pernet_exit+0x19/0x120 net/wireless/core.c:1865
#4: ffff88801be8d180 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_rename_ns+0x76/0x830 fs/kernfs/dir.c:1833
stack backtrace:
CPU: 1 UID: 0 PID: 22262 Comm: kworker/u8:19 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: netns cleanup_net
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043
check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
down_write+0x96/0x200 kernel/locking/rwsem.c:1625
kernfs_unlink_sibling+0x71/0x180 fs/kernfs/dir.c:441
kernfs_rename_ns+0x4a6/0x830 fs/kernfs/dir.c:1873
sysfs_rename_link_ns+0x16e/0x1b0 fs/sysfs/symlink.c:193
device_rename+0x110/0x210 drivers/base/core.c:4558
__dev_change_net_namespace+0x15d3/0x20a0 net/core/dev.c:12673
cfg80211_switch_netns+0x106/0x5a0 net/wireless/core.c:169
cfg80211_pernet_exit+0x92/0x120 net/wireless/core.c:1868
ops_exit_list net/core/net_namespace.c:199 [inline]
ops_undo_list+0x49f/0x940 net/core/net_namespace.c:252
cleanup_net+0x56b/0x800 net/core/net_namespace.c:702
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
kthread+0x389/0x470 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
hsr_slave_0: left promiscuous mode
hsr_slave_1: left promiscuous mode
batman_adv: batadv0: Removing interface: batadv_slave_1
team0 (unregistering): Port device team_slave_1 removed
team0 (unregistering): Port device team_slave_0 removed
IPVS: stop unused estimator thread 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
dvmrp0: left allmulticast mode
pimreg9: left allmulticast mode
bond0 (unregistering): Released all slaves
bond4 (unregistering): (slave gretap1): Releasing active interface
bond6 (unregistering): (slave gretap0): Releasing active interface
batman_adv: 60ªX¹¦À: Removing interface: vlan2
bond2 (unregistering): (slave geneve2): Releasing backup interface
team0: Port device bridge3 removed
bond0 (unregistering): (slave bond_slave_0): Releasing backup interface
bond0 (unregistering): (slave bond_slave_1): Releasing backup interface
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): (slave dummy0): Releasing active interface
dummy0: left promiscuous mode
dummy0: left allmulticast mode
bond9 (unregistering): Released all slaves
tipc: Disabling bearer
tipc: Left network mode
hsr_slave_0: left promiscuous mode
hsr_slave_1: left promiscuous mode
batman_adv: 60ªX¹¦À: Removing interface: batadv_slave_0
team0 (unregistering): Port device team_slave_1 removed
team0 (unregistering): Port device team_slave_0 removed
IPVS: stop unused estimator thread 0...