======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.2.493/5716 is trying to acquire lock:
ffff88807d67cf98 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}, at: __flush_work+0xfa/0x210 kernel/workqueue.c:3090
but task is already holding lock:
ffff88807d67d3f0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1030 net/bluetooth/hci_core.c:1755
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #3 (&hdev->req_lock){+.+.}-{3:3}:
__mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
hci_dev_do_close+0x5f/0x1030 net/bluetooth/hci_core.c:1755
hci_rfkill_set_block+0x10a/0x190 net/bluetooth/hci_core.c:2253
rfkill_set_block+0x1c9/0x3d0 net/rfkill/core.c:360
rfkill_fop_write+0x452/0x560 net/rfkill/core.c:1287
vfs_write+0x30b/0xd60 fs/read_write.c:592
ksys_write+0x152/0x260 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
-> #2 (rfkill_global_mutex){+.+.}-{3:3}:
__mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
rfkill_register+0x33/0x980 net/rfkill/core.c:1060
hci_register_dev+0x452/0x970 net/bluetooth/hci_core.c:3987
__vhci_create_device drivers/bluetooth/hci_vhci.c:129 [inline]
vhci_create_device+0x32c/0x5c0 drivers/bluetooth/hci_vhci.c:153
vhci_get_user drivers/bluetooth/hci_vhci.c:210 [inline]
vhci_write+0x391/0x450 drivers/bluetooth/hci_vhci.c:290
call_write_iter include/linux/fs.h:2173 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x745/0xd60 fs/read_write.c:594
ksys_write+0x152/0x260 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
-> #1 (&data->open_mutex){+.+.}-{3:3}:
__mutex_lock_common+0x1e3/0x2400 kernel/locking/mutex.c:596
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
vhci_send_frame+0x88/0x100 drivers/bluetooth/hci_vhci.c:71
hci_send_frame+0x1a9/0x2e0 net/bluetooth/hci_core.c:4286
hci_sched_acl_pkt net/bluetooth/hci_core.c:4811 [inline]
hci_sched_acl net/bluetooth/hci_core.c:4896 [inline]
hci_tx_work+0x9f9/0x1710 net/bluetooth/hci_core.c:4962
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
-> #0 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain kernel/locking/lockdep.c:3788 [inline]
__lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
__flush_work+0x116/0x210 kernel/workqueue.c:3090
hci_dev_do_close+0x1e7/0x1030 net/bluetooth/hci_core.c:1774
hci_rfkill_set_block+0x10a/0x190 net/bluetooth/hci_core.c:2253
rfkill_set_block+0x1c9/0x3d0 net/rfkill/core.c:360
rfkill_fop_write+0x452/0x560 net/rfkill/core.c:1287
vfs_write+0x30b/0xd60 fs/read_write.c:592
ksys_write+0x152/0x260 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
other info that might help us debug this:
Chain exists of:
(work_completion)(&hdev->tx_work) --> rfkill_global_mutex --> &hdev->req_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&hdev->req_lock);
lock(rfkill_global_mutex);
lock(&hdev->req_lock);
lock((work_completion)(&hdev->tx_work));
*** DEADLOCK ***
2 locks held by syz.2.493/5716:
#0: ffffffff8d6c73e8 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0x18b/0x560 net/rfkill/core.c:1279
#1: ffff88807d67d3f0 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x5f/0x1030 net/bluetooth/hci_core.c:1755
stack backtrace:
CPU: 0 PID: 5716 Comm: syz.2.493 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2133
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain kernel/locking/lockdep.c:3788 [inline]
__lock_acquire+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
__flush_work+0x116/0x210 kernel/workqueue.c:3090
hci_dev_do_close+0x1e7/0x1030 net/bluetooth/hci_core.c:1774
hci_rfkill_set_block+0x10a/0x190 net/bluetooth/hci_core.c:2253
rfkill_set_block+0x1c9/0x3d0 net/rfkill/core.c:360
rfkill_fop_write+0x452/0x560 net/rfkill/core.c:1287
vfs_write+0x30b/0xd60 fs/read_write.c:592
ksys_write+0x152/0x260 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fe1a316ae59
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:00007fe1a13c4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fe1a33e3fa0 RCX: 00007fe1a316ae59
RDX: 0000000000000008 RSI: 0000200000000080 RDI: 0000000000000005
RBP: 00007fe1a3200d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe1a33e4038 R14: 00007fe1a33e3fa0 R15: 00007fff7cf99168
tipc: Resetting bearer