[syzbot] [kernfs?] possible deadlock in kernfs_link_sibling (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2d1373e4246d Merge tag 'for-7.0-rc4-tag' of git://git.kern..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13ab3406580000
kernel config: https://syzkaller.appspot.com/x/.config?x=45cb3c58fd963c27
dashboard link: https://syzkaller.appspot.com/bug?extid=dd764a450d93885d847f
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b8f9fdb26fea/disk-2d1373e4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1f20580466c5/vmlinux-2d1373e4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f051fb6711e4/bzImage-2d1373e4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+dd764a...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G L
------------------------------------------------------
kworker/u9:1/11370 is trying to acquire lock:
ffff888019c4f2c0 (&root->kernfs_iattr_rwsem){++++}-{4:4}, at: kernfs_link_sibling+0x46c/0x540 fs/kernfs/dir.c:394

but task is already holding lock:
ffff888019c4f238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x41/0x5c0 fs/kernfs/dir.c:796

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #10 (&root->kernfs_rwsem){++++}-{4:4}:
down_write+0x3a/0x50 kernel/locking/rwsem.c:1590
kernfs_add_one+0x41/0x5c0 fs/kernfs/dir.c:796
kernfs_create_dir_ns+0xde/0x130 fs/kernfs/dir.c:1098
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+0x250/0x8d0 init/main.c:1382
do_initcall_level+0x104/0x190 init/main.c:1444
do_initcalls+0x59/0xa0 init/main.c:1460
kernel_init_freeable+0x2a6/0x3e0 init/main.c:1692
kernel_init+0x1d/0x1d0 init/main.c:1582
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

-> #9 (cpuhp_state_mutex){+.+.}-{4:4}:

-> #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+0x42/0x160 kernel/cpu.c:490
static_key_slow_inc+0x12/0x30 kernel/jump_label.c:190
tcp_md5_do_add+0x1d4/0x390 net/ipv4/tcp_ipv4.c:1431
tcp_v6_parse_md5_keys+0x562/0x680 net/ipv6/tcp_ipv6.c:-1
do_tcp_setsockopt+0x12ee/0x2060 net/ipv4/tcp.c:4134
do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2322
__sys_setsockopt net/socket.c:2347 [inline]
__do_sys_setsockopt net/socket.c:2353 [inline]
__se_sys_setsockopt net/socket.c:2350 [inline]
__x64_sys_setsockopt+0x143/0x1b0 net/socket.c:2350
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #7 (sk_lock-AF_INET6){+.+.}-{0:0}:
lock_sock_nested+0x3e/0x130 net/core/sock.c:3780
lock_sock include/net/sock.h:1709 [inline]
inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:919
nbd_mark_nsock_dead+0x2e9/0x560 drivers/block/nbd.c:318
recv_work+0x1c9d/0x1dc0 drivers/block/nbd.c:1021
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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/rtmutex_api.c:533 [inline]
mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
nbd_handle_cmd drivers/block/nbd.c:1143 [inline]
nbd_queue_rq+0x37b/0x1100 drivers/block/nbd.c:1207
blk_mq_dispatch_rq_list+0xa77/0x1910 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+0xddb/0x1610 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xda/0x1a0 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x368/0x520 block/blk-mq.c:2386
blk_mq_dispatch_list+0xd1f/0xe20 include/linux/spinlock_rt.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+0x2f4/0xa70 block/blk-core.c:753
submit_bh fs/buffer.c:2826 [inline]
block_read_full_folio+0x599/0x830 fs/buffer.c:2444
filemap_read_folio+0x137/0x3b0 mm/filemap.c:2501
do_read_cache_folio+0x2bf/0x560 mm/filemap.c:4101
read_mapping_folio include/linux/pagemap.h:1028 [inline]
read_part_sector+0xb8/0x2b0 block/partitions/core.c:723
adfspart_check_ICS+0xa5/0xa40 block/partitions/acorn.c:360
check_partition block/partitions/core.c:142 [inline]
blk_add_partitions block/partitions/core.c:590 [inline]
bdev_disk_changed+0x7ba/0x1550 block/partitions/core.c:694
blkdev_get_whole+0x2e5/0x480 block/bdev.c:764
bdev_open+0x31e/0xcc0 block/bdev.c:973
blkdev_open+0x485/0x620 block/fops.c:697
do_dentry_open+0x83d/0x13e0 fs/open.c:949
vfs_open+0x3b/0x350 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x2e43/0x38a0 fs/namei.c:4830
do_file_open+0x23e/0x4a0 fs/namei.c:4859
do_sys_openat2+0x113/0x200 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/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/rtmutex_api.c:533 [inline]
mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
nbd_queue_rq+0xc6/0x1100 drivers/block/nbd.c:1199
blk_mq_dispatch_rq_list+0xa77/0x1910 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+0xddb/0x1610 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xda/0x1a0 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x368/0x520 block/blk-mq.c:2386
blk_mq_dispatch_list+0xd1f/0xe20 include/linux/spinlock_rt.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+0x2f4/0xa70 block/blk-core.c:753
submit_bh fs/buffer.c:2826 [inline]
block_read_full_folio+0x599/0x830 fs/buffer.c:2444
filemap_read_folio+0x137/0x3b0 mm/filemap.c:2501
do_read_cache_folio+0x2bf/0x560 mm/filemap.c:4101
read_mapping_folio include/linux/pagemap.h:1028 [inline]
read_part_sector+0xb8/0x2b0 block/partitions/core.c:723
adfspart_check_ICS+0xa5/0xa40 block/partitions/acorn.c:360
check_partition block/partitions/core.c:142 [inline]
blk_add_partitions block/partitions/core.c:590 [inline]
bdev_disk_changed+0x7ba/0x1550 block/partitions/core.c:694
blkdev_get_whole+0x2e5/0x480 block/bdev.c:764
bdev_open+0x31e/0xcc0 block/bdev.c:973
blkdev_open+0x485/0x620 block/fops.c:697
do_dentry_open+0x83d/0x13e0 fs/open.c:949
vfs_open+0x3b/0x350 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x2e43/0x38a0 fs/namei.c:4830
do_file_open+0x23e/0x4a0 fs/namei.c:4859
do_sys_openat2+0x113/0x200 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/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/0x3e0 kernel/rcu/srcutree.c:1505
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+0x366/0x430 block/blk-sysfs.c:946
__add_disk+0x677/0xd50 block/genhd.c:528
add_disk_fwnode+0xfb/0x480 block/genhd.c:597
add_disk include/linux/blkdev.h:785 [inline]
nbd_dev_add+0x72c/0xb50 drivers/block/nbd.c:1984
nbd_init+0x168/0x1f0 drivers/block/nbd.c:2692
do_one_initcall+0x250/0x8d0 init/main.c:1382
do_initcall_level+0x104/0x190 init/main.c:1444
do_initcalls+0x59/0xa0 init/main.c:1460
kernel_init_freeable+0x2a6/0x3e0 init/main.c:1692
kernel_init+0x1d/0x1d0 init/main.c:1582
ret_from_fork+0x51e/0xb90 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/rtmutex_api.c:533 [inline]
mutex_lock_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:552
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:5110 [inline]
__blk_mq_update_nr_hw_queues block/blk-mq.c:5155 [inline]
blk_mq_update_nr_hw_queues+0x607/0x1a80 block/blk-mq.c:5220
nbd_start_device+0x17f/0xb20 drivers/block/nbd.c:1489
nbd_genl_connect+0x1651/0x1c80 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:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x831/0x9f0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0x94c/0x9c0 net/socket.c:2592
___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2683 [inline]
__se_sys_sendmsg net/socket.c:2681 [inline]
__x64_sys_sendmsg+0x1c3/0x2a0 net/socket.c:2681
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #2 (&q->q_usage_counter(io)#75){++++}-{0:0}:
blk_alloc_queue+0x54e/0x690 block/blk-core.c:461
blk_mq_alloc_queue block/blk-mq.c:4429 [inline]
__blk_mq_alloc_disk+0x197/0x390 block/blk-mq.c:4476
nbd_dev_add+0x499/0xb50 drivers/block/nbd.c:1954
nbd_genl_connect+0x965/0x1c80 drivers/block/nbd.c:2125
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:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x831/0x9f0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
____sys_sendmsg+0x94c/0x9c0 net/socket.c:2592
___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
__sys_sendmsg net/socket.c:2678 [inline]
__do_sys_sendmsg net/socket.c:2683 [inline]
__se_sys_sendmsg net/socket.c:2681 [inline]
__x64_sys_sendmsg+0x1c3/0x2a0 net/socket.c:2681
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (fs_reclaim){+.+.}-{0:0}:
__fs_reclaim_acquire mm/page_alloc.c:4348 [inline]
fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4362
might_alloc include/linux/sched/mm.h:317 [inline]
slab_pre_alloc_hook mm/slub.c:4489 [inline]
slab_alloc_node mm/slub.c:4843 [inline]
kmem_cache_alloc_noprof+0x44/0x680 mm/slub.c:4873
__kernfs_iattrs+0xdf/0x340 fs/kernfs/inode.c:36
kernfs_iattrs fs/kernfs/inode.c:61 [inline]
__kernfs_setattr fs/kernfs/inode.c:74 [inline]
kernfs_iop_setattr+0xea/0x3f0 fs/kernfs/inode.c:128
notify_change+0xc18/0xf60 fs/attr.c:556
do_truncate+0x1c2/0x250 fs/open.c:68
handle_truncate fs/namei.c:4279 [inline]
do_open fs/namei.c:4675 [inline]
path_openat+0x2fc4/0x38a0 fs/namei.c:4830
do_file_open+0x23e/0x4a0 fs/namei.c:4859
do_sys_openat2+0x113/0x200 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/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+0xf0/0x2e0 kernel/locking/lockdep.c:5868
down_write+0x3a/0x50 kernel/locking/rwsem.c:1590
kernfs_link_sibling+0x46c/0x540 fs/kernfs/dir.c:394
kernfs_add_one+0x1ca/0x5c0 fs/kernfs/dir.c:815
kernfs_create_dir_ns+0xde/0x130 fs/kernfs/dir.c:1098
sysfs_create_dir_ns+0x12f/0x2a0 fs/sysfs/dir.c:59
create_dir lib/kobject.c:73 [inline]
kobject_add_internal+0x631/0xd10 lib/kobject.c:240
kobject_add_varg lib/kobject.c:374 [inline]
kobject_add+0x163/0x240 lib/kobject.c:426
device_add+0x408/0xb80 drivers/base/core.c:3627
hci_conn_add_sysfs+0xd5/0x210 net/bluetooth/hci_sysfs.c:48
hci_conn_complete_evt+0x77a/0x11d0 net/bluetooth/hci_event.c:3195
hci_event_func net/bluetooth/hci_event.c:7784 [inline]
hci_event_packet+0x805/0x12c0 net/bluetooth/hci_event.c:7838
hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4077
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 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 ***

4 locks held by kworker/u9:1/11370:
#0: ffff888033cf8938 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff888033cf8938 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc90005fefc40 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc90005fefc40 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffff8880392140b0 (&hdev->lock){+.+.}-{4:4}, at: hci_conn_complete_evt+0xbb/0x11d0 net/bluetooth/hci_event.c:3113
#3: ffff888019c4f238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x41/0x5c0 fs/kernfs/dir.c:796

stack backtrace:
CPU: 0 UID: 0 PID: 11370 Comm: kworker/u9:1 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: hci0 hci_rx_work
Call Trace:
<TASK>
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+0xf0/0x2e0 kernel/locking/lockdep.c:5868
down_write+0x3a/0x50 kernel/locking/rwsem.c:1590
kernfs_link_sibling+0x46c/0x540 fs/kernfs/dir.c:394
kernfs_add_one+0x1ca/0x5c0 fs/kernfs/dir.c:815
kernfs_create_dir_ns+0xde/0x130 fs/kernfs/dir.c:1098
sysfs_create_dir_ns+0x12f/0x2a0 fs/sysfs/dir.c:59
create_dir lib/kobject.c:73 [inline]
kobject_add_internal+0x631/0xd10 lib/kobject.c:240
kobject_add_varg lib/kobject.c:374 [inline]
kobject_add+0x163/0x240 lib/kobject.c:426
device_add+0x408/0xb80 drivers/base/core.c:3627
hci_conn_add_sysfs+0xd5/0x210 net/bluetooth/hci_sysfs.c:48
hci_conn_complete_evt+0x77a/0x11d0 net/bluetooth/hci_event.c:3195
hci_event_func net/bluetooth/hci_event.c:7784 [inline]
hci_event_packet+0x805/0x12c0 net/bluetooth/hci_event.c:7838
hci_rx_work+0x3ee/0x1030 net/bluetooth/hci_core.c:4077
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>


---
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