RBP: 0000000000000007 R08: 0000000000000000 R09: ffffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 0000000000000006 R14: 0000000020000248 R15: 0000000000000003
======================================================
WARNING: possible circular locking dependency detected
5.10.214 #1 Not tainted
------------------------------------------------------
syz-executor.5/15053 is trying to acquire lock:
ffff88800db88ae8 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}, at: __flush_work+0xdd/0xa90 kernel/workqueue.c:3050

but task is already holding lock:
ffff88800db88f40 (&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:3774
       __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:4061
       hci_sched_acl_pkt net/bluetooth/hci_core.c:4586 [inline]
       hci_sched_acl net/bluetooth/hci_core.c:4671 [inline]
       hci_tx_work+0x10af/0x1660 net/bluetooth/hci_core.c:4742
       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:3729 [inline]
       __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4955
       lock_acquire kernel/locking/lockdep.c:5566 [inline]
       lock_acquire+0x197/0x470 kernel/locking/lockdep.c:5531
       __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.5/15053:
 #0: ffffffff8561a8c8 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0xff/0x4b0 net/rfkill/core.c:1232
 #1: ffff88800db88f40 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0xef/0x1240 net/bluetooth/hci_core.c:1734

stack backtrace:
CPU: 0 PID: 15053 Comm: syz-executor.5 Not tainted 5.10.214 #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:3729 [inline]
 __lock_acquire+0x29e7/0x5b00 kernel/locking/lockdep.c:4955
 lock_acquire kernel/locking/lockdep.c:5566 [inline]
 lock_acquire+0x197/0x470 kernel/locking/lockdep.c:5531
 __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: 0033:0x7fb97c9e2b19
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:00007fb979f58188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb97caf5f60 RCX: 00007fb97c9e2b19
RDX: 0000000000000008 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00007fb97ca3cf6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd468cc47f R14: 00007fb979f58300 R15: 0000000000022000
mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium
audit: type=1400 audit(1712048182.353:169): avc:  denied  { associate } for  pid=15168 comm="syz-executor.1" name="nvram" dev="devtmpfs" ino=99 scontext=system_u:object_r:syslogd_var_lib_t:s0 tcontext=system_u:object_r:device_t:s0 tclass=filesystem permissive=1
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 15178 Comm: syz-executor.6 Not tainted 5.10.214 #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
 kmem_cache_zalloc include/linux/slab.h:654 [inline]
 __kernfs_new_node+0xd4/0x860 fs/kernfs/dir.c:635
 kernfs_new_node+0x18d/0x250 fs/kernfs/dir.c:711
 kernfs_create_dir_ns+0x49/0x160 fs/kernfs/dir.c:1047
 internal_create_group+0x793/0xb30 fs/sysfs/group.c:137
 loop_sysfs_init drivers/block/loop.c:853 [inline]
 loop_configure+0x954/0x1480 drivers/block/loop.c:1159
 lo_ioctl+0xa72/0x1760 drivers/block/loop.c:1687
 __blkdev_driver_ioctl block/ioctl.c:237 [inline]
 blkdev_ioctl+0x291/0x710 block/ioctl.c:637
 block_ioctl+0xf9/0x140 fs/block_dev.c:1893
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x62/0xc7
RIP: 0033:0x7f27dcc548d7
Code: 3c 1c 48 f7 d8 49 39 c4 72 b8 e8 a4 54 02 00 85 c0 78 bd 48 83 c4 08 4c 89 e0 5b 41 5c c3 0f 1f 44 00 00 b8 10 00 00 00 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:00007f27da1c9f48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f27dcc9e970 RCX: 00007f27dcc548d7
RDX: 0000000000000006 RSI: 0000000000004c00 RDI: 0000000000000007
RBP: 0000000000000007 R08: 0000000000000000 R09: ffffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 0000000000000006 R14: 0000000020000248 R15: 0000000000000003
mac80211_hwsim: wmediumd released netlink socket, switching to perfect channel medium
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 0 PID: 15293 Comm: syz-executor.6 Not tainted 5.10.214 #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
 kmem_cache_zalloc include/linux/slab.h:654 [inline]
 __kernfs_new_node+0xd4/0x860 fs/kernfs/dir.c:635
 kernfs_new_node+0x18d/0x250 fs/kernfs/dir.c:711
 kernfs_create_dir_ns+0x49/0x160 fs/kernfs/dir.c:1047
 internal_create_group+0x793/0xb30 fs/sysfs/group.c:137
 loop_sysfs_init drivers/block/loop.c:853 [inline]
 loop_configure+0x954/0x1480 drivers/block/loop.c:1159
 lo_ioctl+0xa72/0x1760 drivers/block/loop.c:1687
 __blkdev_driver_ioctl block/ioctl.c:237 [inline]
 blkdev_ioctl+0x291/0x710 block/ioctl.c:637
 block_ioctl+0xf9/0x140 fs/block_dev.c:1893
 vfs_ioctl fs/ioctl.c:48 [inline]
 __do_sys_ioctl fs/ioctl.c:753 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x19a/0x210 fs/ioctl.c:739
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x62/0xc7
RIP: 0033:0x7f27dcc548d7
Code: 3c 1c 48 f7 d8 49 39 c4 72 b8 e8 a4 54 02 00 85 c0 78 bd 48 83 c4 08 4c 89 e0 5b 41 5c c3 0f 1f 44 00 00 b8 10 00 00 00 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:00007f27da1c9f48 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f27dcc9e970 RCX: 00007f27dcc548d7
RDX: 0000000000000006 RSI: 0000000000004c00 RDI: 0000000000000007
RBP: 0000000000000007 R08: 0000000000000000 R09: ffffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000006
R13: 0000000000000006 R14: 0000000020000248 R15: 0000000000000003