======================================================
WARNING: possible circular locking dependency detected
5.10.200 #1 Not tainted
------------------------------------------------------
syz-executor.5/7670 is trying to acquire lock:
ffff888009290ae8 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}, at: __flush_work+0xdd/0xa90 kernel/workqueue.c:3050

but task is already holding lock:
ffff888009290f40 (&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:
audit: type=1326 audit(1700224879.027:99): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=7678 comm="syz-executor.0" exe="/syz-executor.0" sig=0 arch=c000003e syscall=257 compat=0 ip=0x7fbd230e1a04 code=0x7ffc0000

-> #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
audit: type=1326 audit(1700224879.028:100): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=7678 comm="syz-executor.0" exe="/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fbd2312eb19 code=0x7ffc0000
       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.5/7670:
 #0: ffffffff85619468 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0xff/0x4b0 net/rfkill/core.c:1232
 #1: ffff888009290f40 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0xef/0x1240 net/bluetooth/hci_core.c:1734

stack backtrace:
CPU: 0 PID: 7670 Comm: syz-executor.5 Not tainted 5.10.200 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
audit: type=1326 audit(1700224879.028:101): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=7678 comm="syz-executor.0" exe="/syz-executor.0" sig=0 arch=c000003e syscall=259 compat=0 ip=0x7fbd2312eb19 code=0x7ffc0000
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
audit: type=1326 audit(1700224879.029:102): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=7678 comm="syz-executor.0" exe="/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fbd2312eb19 code=0x7ffc0000
 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
audit: type=1326 audit(1700224879.032:103): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=7678 comm="syz-executor.0" exe="/syz-executor.0" sig=0 arch=c000003e syscall=332 compat=0 ip=0x7fbd2312eb19 code=0x7ffc0000
 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: 0033:0x7fc2dee96b19
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
audit: type=1326 audit(1700224879.032:104): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=7678 comm="syz-executor.0" exe="/syz-executor.0" sig=0 arch=c000003e syscall=202 compat=0 ip=0x7fbd2312eb19 code=0x7ffc0000
RSP: 002b:00007fc2dc40c188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc2defa9f60 RCX: 00007fc2dee96b19
RDX: 0000000000000008 RSI: 00000000200000c0 RDI: 0000000000000004
RBP: 00007fc2deef0f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc47aea37f R14: 00007fc2dc40c300 R15: 0000000000022000
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
audit: type=1326 audit(1700224879.032:105): auid=0 uid=0 gid=0 ses=4 subj=system_u:system_r:kernel_t:s0 pid=7678 comm="syz-executor.0" exe="/syz-executor.0" sig=0 arch=c000003e syscall=332 compat=0 ip=0x7fbd2312eb19 code=0x7ffc0000
CPU: 0 PID: 7690 Comm: syz-executor.3 Not tainted 5.10.200 #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
 should_failslab+0x5/0x20 mm/slab_common.c:1193
 slab_pre_alloc_hook mm/slab.h:515 [inline]
 slab_alloc_node mm/slub.c:2821 [inline]
 slab_alloc mm/slub.c:2904 [inline]
 kmem_cache_alloc+0x5b/0x310 mm/slub.c:2909
 mem_pool_alloc mm/kmemleak.c:423 [inline]
 create_object.isra.0+0x3a/0xa20 mm/kmemleak.c:578
 kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
 slab_post_alloc_hook mm/slab.h:534 [inline]
 slab_alloc_node mm/slub.c:2896 [inline]
 slab_alloc mm/slub.c:2904 [inline]
 kmem_cache_alloc+0x159/0x310 mm/slub.c:2909
 shmem_alloc_inode+0x18/0x40 mm/shmem.c:3852
 alloc_inode+0x63/0x240 fs/inode.c:233
 new_inode_pseudo fs/inode.c:929 [inline]
 new_inode+0x23/0x250 fs/inode.c:958
 shmem_get_inode+0x15e/0xbc0 mm/shmem.c:2294
 shmem_symlink+0xe2/0x750 mm/shmem.c:3155
 vfs_symlink fs/namei.c:4021 [inline]
 vfs_symlink+0x374/0x580 fs/namei.c:4007
 do_symlinkat+0x13c/0x280 fs/namei.c:4048
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x62/0xc7
RIP: 0033:0x7fa97c3f3b19
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:00007fa979969188 EFLAGS: 00000246 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 00007fa97c506f60 RCX: 00007fa97c3f3b19
RDX: 00000000200000c0 RSI: 0000000000000004 RDI: 0000000020000040
RBP: 00007fa9799691d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
R13: 00007fff49b27d3f R14: 00007fa979969300 R15: 0000000000022000