======================================================
WARNING: possible circular locking dependency detected
5.10.199 #1 Not tainted
------------------------------------------------------
syz-executor.4/7848 is trying to acquire lock:
ffff88800eee4ae8 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}, at: __flush_work+0xdd/0xa90 kernel/workqueue.c:3050

but task is already holding lock:
ffff88800eee4f40 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0xef/0x1240 net/bluetooth/hci_core.c:1734

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 kernel/locking/mutex.c:968 [inline]
       __mutex_lock+0x13d/0x10b0 kernel/locking/mutex.c:1109
       hci_dev_do_close+0xef/0x1240 net/bluetooth/hci_core.c:1734
       hci_rfkill_set_block+0x166/0x1a0 net/bluetooth/hci_core.c:2223
       rfkill_set_block+0x1fd/0x540 net/rfkill/core.c:341
       rfkill_fop_write+0x253/0x4b0 net/rfkill/core.c:1240
       vfs_write+0x29a/0xa70 fs/read_write.c:603
       ksys_write+0x1f6/0x260 fs/read_write.c:658
       do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x62/0xc7

-> #2 (rfkill_global_mutex){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:968 [inline]
       __mutex_lock+0x13d/0x10b0 kernel/locking/mutex.c:1109
       rfkill_register+0x36/0xa10 net/rfkill/core.c:1016
       hci_register_dev+0x42e/0xc00 net/bluetooth/hci_core.c:3773
       __vhci_create_device+0x2c8/0x5c0 drivers/bluetooth/hci_vhci.c:129
       vhci_create_device drivers/bluetooth/hci_vhci.c:153 [inline]
       vhci_open_timeout+0x38/0x50 drivers/bluetooth/hci_vhci.c:310
       process_one_work+0x9a9/0x14b0 kernel/workqueue.c:2282
       worker_thread+0x61d/0x1310 kernel/workqueue.c:2428
       kthread+0x38f/0x470 kernel/kthread.c:313
       ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:299

-> #1 (&data->open_mutex){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:968 [inline]
       __mutex_lock+0x13d/0x10b0 kernel/locking/mutex.c:1109
       vhci_send_frame+0x63/0xa0 drivers/bluetooth/hci_vhci.c:71
       hci_send_frame+0x1b9/0x320 net/bluetooth/hci_core.c:4060
       hci_sched_acl_pkt net/bluetooth/hci_core.c:4585 [inline]
       hci_sched_acl net/bluetooth/hci_core.c:4670 [inline]
       hci_tx_work+0x10af/0x1660 net/bluetooth/hci_core.c:4741
       process_one_work+0x9a9/0x14b0 kernel/workqueue.c:2282
       worker_thread+0x61d/0x1310 kernel/workqueue.c:2428
       kthread+0x38f/0x470 kernel/kthread.c:313
       ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:299

-> #0 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:2988 [inline]
       check_prevs_add kernel/locking/lockdep.c:3113 [inline]
       validate_chain kernel/locking/lockdep.c:3728 [inline]
       __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4954
       lock_acquire kernel/locking/lockdep.c:5565 [inline]
       lock_acquire+0x197/0x470 kernel/locking/lockdep.c:5530
       __flush_work+0x105/0xa90 kernel/workqueue.c:3053
       hci_dev_do_close+0x131/0x1240 net/bluetooth/hci_core.c:1745
       hci_rfkill_set_block+0x166/0x1a0 net/bluetooth/hci_core.c:2223
       rfkill_set_block+0x1fd/0x540 net/rfkill/core.c:341
       rfkill_fop_write+0x253/0x4b0 net/rfkill/core.c:1240
       vfs_write+0x29a/0xa70 fs/read_write.c:603
       ksys_write+0x1f6/0x260 fs/read_write.c:658
       do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x62/0xc7

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-executor.4/7848:
 #0: ffffffff85619468 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0xff/0x4b0 net/rfkill/core.c:1232
 #1: ffff88800eee4f40 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0xef/0x1240 net/bluetooth/hci_core.c:1734

stack backtrace:
CPU: 1 PID: 7848 Comm: syz-executor.4 Not tainted 5.10.199 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x167 lib/dump_stack.c:118
 check_noncircular+0x263/0x2e0 kernel/locking/lockdep.c:2123
 check_prev_add kernel/locking/lockdep.c:2988 [inline]
 check_prevs_add kernel/locking/lockdep.c:3113 [inline]
 validate_chain kernel/locking/lockdep.c:3728 [inline]
 __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4954
 lock_acquire kernel/locking/lockdep.c:5565 [inline]
 lock_acquire+0x197/0x470 kernel/locking/lockdep.c:5530
 __flush_work+0x105/0xa90 kernel/workqueue.c:3053
 hci_dev_do_close+0x131/0x1240 net/bluetooth/hci_core.c:1745
 hci_rfkill_set_block+0x166/0x1a0 net/bluetooth/hci_core.c:2223
 rfkill_set_block+0x1fd/0x540 net/rfkill/core.c:341
 rfkill_fop_write+0x253/0x4b0 net/rfkill/core.c:1240
 vfs_write+0x29a/0xa70 fs/read_write.c:603
 ksys_write+0x1f6/0x260 fs/read_write.c:658
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x62/0xc7
RIP: 0033:0x7f387a313b19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3877889188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f387a426f60 RCX: 00007f387a313b19
RDX: 0000000000000008 RSI: 00000000200000c0 RDI: 0000000000000007
RBP: 00007f387a36df6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdd46bd64f R14: 00007f3877889300 R15: 0000000000022000
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 7853 Comm: syz-executor.7 Not tainted 5.10.199 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
device lo left promiscuous mode
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x167 lib/dump_stack.c:118
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail.cold+0x5/0xa lib/fault-inject.c:146
 _copy_from_user+0x2e/0x1b0 lib/usercopy.c:15
 copy_from_user include/linux/uaccess.h:192 [inline]
 __copy_msghdr_from_user+0x91/0x4b0 net/socket.c:2258
 copy_msghdr_from_user net/socket.c:2309 [inline]
 recvmsg_copy_msghdr net/socket.c:2561 [inline]
 ___sys_recvmsg+0xd5/0x200 net/socket.c:2633
 do_recvmmsg+0x24c/0x6d0 net/socket.c:2731
 __sys_recvmmsg net/socket.c:2810 [inline]
 __do_sys_recvmmsg net/socket.c:2833 [inline]
 __se_sys_recvmmsg net/socket.c:2826 [inline]
 __x64_sys_recvmmsg+0x20f/0x260 net/socket.c:2826
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x62/0xc7
RIP: 0033:0x7fd50191ab19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd4fee90188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fd501a2df60 RCX: 00007fd50191ab19
RDX: 000000000000035f RSI: 0000000020001a00 RDI: 0000000000000004
RBP: 00007fd4fee901d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000010062 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffcb71c4b0f R14: 00007fd4fee90300 R15: 0000000000022000
device lo entered promiscuous mode
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 7871 Comm: syz-executor.1 Not tainted 5.10.199 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x167 lib/dump_stack.c:118
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail.cold+0x5/0xa lib/fault-inject.c:146
 _copy_from_user+0x2e/0x1b0 lib/usercopy.c:15
 copy_from_user include/linux/uaccess.h:192 [inline]
 __copy_msghdr_from_user+0x91/0x4b0 net/socket.c:2258
 copy_msghdr_from_user net/socket.c:2309 [inline]
 recvmsg_copy_msghdr net/socket.c:2561 [inline]
 ___sys_recvmsg+0xd5/0x200 net/socket.c:2633
 do_recvmmsg+0x24c/0x6d0 net/socket.c:2731
 __sys_recvmmsg net/socket.c:2810 [inline]
 __do_sys_recvmmsg net/socket.c:2833 [inline]
 __se_sys_recvmmsg net/socket.c:2826 [inline]
 __x64_sys_recvmmsg+0x20f/0x260 net/socket.c:2826
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x62/0xc7
RIP: 0033:0x7f65a52bbb19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f65a2831188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f65a53cef60 RCX: 00007f65a52bbb19
RDX: 000000000000035f RSI: 0000000020001a00 RDI: 0000000000000004
RBP: 00007f65a28311d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000010062 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffc95f579af R14: 00007f65a2831300 R15: 0000000000022000
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 7885 Comm: syz-executor.6 Not tainted 5.10.199 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x167 lib/dump_stack.c:118
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail.cold+0x5/0xa lib/fault-inject.c:146
 _copy_from_user+0x2e/0x1b0 lib/usercopy.c:15
 copy_from_user include/linux/uaccess.h:192 [inline]
 __copy_msghdr_from_user+0x91/0x4b0 net/socket.c:2258
 copy_msghdr_from_user net/socket.c:2309 [inline]
 recvmsg_copy_msghdr net/socket.c:2561 [inline]
 ___sys_recvmsg+0xd5/0x200 net/socket.c:2633
 do_recvmmsg+0x24c/0x6d0 net/socket.c:2731
 __sys_recvmmsg net/socket.c:2810 [inline]
 __do_sys_recvmmsg net/socket.c:2833 [inline]
 __se_sys_recvmmsg net/socket.c:2826 [inline]
 __x64_sys_recvmmsg+0x20f/0x260 net/socket.c:2826
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x62/0xc7
RIP: 0033:0x7f301b410b19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3018986188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f301b523f60 RCX: 00007f301b410b19
RDX: 000000000000035f RSI: 0000000020001a00 RDI: 0000000000000004
RBP: 00007f30189861d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000010062 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffcb222f7cf R14: 00007f3018986300 R15: 0000000000022000
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 7877 Comm: syz-executor.7 Not tainted 5.10.199 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x167 lib/dump_stack.c:118
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail.cold+0x5/0xa lib/fault-inject.c:146
 _copy_from_user+0x2e/0x1b0 lib/usercopy.c:15
 copy_from_user include/linux/uaccess.h:192 [inline]
 __copy_msghdr_from_user+0x91/0x4b0 net/socket.c:2258
 copy_msghdr_from_user net/socket.c:2309 [inline]
 recvmsg_copy_msghdr net/socket.c:2561 [inline]
 ___sys_recvmsg+0xd5/0x200 net/socket.c:2633
 do_recvmmsg+0x24c/0x6d0 net/socket.c:2731
 __sys_recvmmsg net/socket.c:2810 [inline]
 __do_sys_recvmmsg net/socket.c:2833 [inline]
 __se_sys_recvmmsg net/socket.c:2826 [inline]
 __x64_sys_recvmmsg+0x20f/0x260 net/socket.c:2826
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x62/0xc7
RIP: 0033:0x7fd50191ab19
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd4fee90188 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fd501a2df60 RCX: 00007fd50191ab19
RDX: 000000000000035f RSI: 0000000020001a00 RDI: 0000000000000004
RBP: 00007fd4fee901d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000010062 R11: 0000000000000246 R12: 0000000000000002
R13: 00007ffcb71c4b0f R14: 00007fd4fee90300 R15: 0000000000022000
device lo left promiscuous mode
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 7884 Comm: syz-executor.0 Not tainted 5.10.199 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x167 lib/dump_stack.c:118
 fail_dump lib/fault-inject.c:52 [inline]
 should_fail.cold+0x5/0xa lib/fault-inject.c:146
 _copy_from_user+0x2e/0x1b0 lib/usercopy.c:15
 copy_from_user include/linux/uaccess.h:192 [inline]
 __copy_msghdr_from_user+0x91/0x4b0 net/socket.c:2258
 copy_msghdr_from_user net/socket.c:2309 [inline]
 recvmsg_copy_msghdr net/socket.c:2561 [inline]
 ___sys_recvmsg+0xd5/0x200 net/socket.c:2633
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
 do_recvmmsg+0x24c/0x6d0 net/socket.c:2731