R13: 00007ffdcfb31eaf R14: 00007ffbdb4da300 R15: 0000000000022000
netlink: 64 bytes leftover after parsing attributes in process `syz-executor.2'.
======================================================
WARNING: possible circular locking dependency detected
5.10.202 #1 Not tainted
------------------------------------------------------
syz-executor.6/14935 is trying to acquire lock:
ffff88800f268b78 ((work_completion)(&hdev->bg_scan_update)){+.+.}-{0:0}, at: __flush_work+0xdd/0xa90 kernel/workqueue.c:3050

but task is already holding lock:
ffffffff856193e8 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0xff/0x4b0 net/rfkill/core.c:1232

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (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

-> #3 (&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

-> #2 ((work_completion)(&hdev->tx_work)){+.+.}-{0:0}:
       __flush_work+0x105/0xa90 kernel/workqueue.c:3053
       hci_dev_do_close+0x131/0x1240 net/bluetooth/hci_core.c:1745
       hci_unregister_dev+0x149/0x430 net/bluetooth/hci_core.c:3849
       vhci_release+0x70/0xf0 drivers/bluetooth/hci_vhci.c:345
       __fput+0x285/0x980 fs/file_table.c:281
       task_work_run+0xe2/0x1a0 kernel/task_work.c:161
       exit_task_work include/linux/task_work.h:32 [inline]
       do_exit+0xb6f/0x2600 kernel/exit.c:858
       do_group_exit+0x125/0x310 kernel/exit.c:980
       __do_sys_exit_group kernel/exit.c:991 [inline]
       __se_sys_exit_group kernel/exit.c:989 [inline]
       __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:989
       do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
       entry_SYSCALL_64_after_hwframe+0x62/0xc7

-> #1 (&hdev->req_lock){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:968 [inline]
       __mutex_lock+0x13d/0x10b0 kernel/locking/mutex.c:1109
       hci_req_sync net/bluetooth/hci_request.c:275 [inline]
       bg_scan_update+0x82/0x500 net/bluetooth/hci_request.c:2895
       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->bg_scan_update)){+.+.}-{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
       __cancel_work_timer+0x368/0x4c0 kernel/workqueue.c:3144
       hci_request_cancel_all+0x73/0x230 net/bluetooth/hci_request.c:3438
       hci_dev_do_close+0xd9/0x1240 net/bluetooth/hci_core.c:1733
       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->bg_scan_update) --> &data->open_mutex --> rfkill_global_mutex

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(rfkill_global_mutex);
                               lock(&data->open_mutex);
                               lock(rfkill_global_mutex);
  lock((work_completion)(&hdev->bg_scan_update));

 *** DEADLOCK ***

1 lock held by syz-executor.6/14935:
 #0: ffffffff856193e8 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0xff/0x4b0 net/rfkill/core.c:1232

stack backtrace:
CPU: 0 PID: 14935 Comm: syz-executor.6 Not tainted 5.10.202 #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
 __cancel_work_timer+0x368/0x4c0 kernel/workqueue.c:3144
 hci_request_cancel_all+0x73/0x230 net/bluetooth/hci_request.c:3438
 hci_dev_do_close+0xd9/0x1240 net/bluetooth/hci_core.c:1733
 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: 0033:0x7f8bfc55fb19
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:00007f8bf9ad5188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f8bfc672f60 RCX: 00007f8bfc55fb19
RDX: 0000000000000008 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00007f8bfc5b9f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc1a027a2f R14: 00007f8bf9ad5300 R15: 0000000000022000
FAULT_INJECTION: forcing a failure.
name failslab, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 14970 Comm: syz-executor.7 Not tainted 5.10.202 #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
 skb_clone+0x14f/0x3d0 net/core/skbuff.c:1456
 raw_v4_input net/ipv4/raw.c:192 [inline]
 raw_local_deliver+0x742/0xb10 net/ipv4/raw.c:218
 ip_protocol_deliver_rcu+0xe6/0x790 net/ipv4/ip_input.c:193
 ip_local_deliver_finish+0x20c/0x3b0 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:296 [inline]
 NF_HOOK include/linux/netfilter.h:290 [inline]
 ip_local_deliver+0x1b7/0x200 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:442 [inline]
 ip_rcv_finish+0xec/0x1e0 net/ipv4/ip_input.c:440
 NF_HOOK include/linux/netfilter.h:296 [inline]
 NF_HOOK include/linux/netfilter.h:290 [inline]
 ip_rcv+0xae/0xd0 net/ipv4/ip_input.c:551
 __netif_receive_skb_one_core+0x19b/0x1f0 net/core/dev.c:5367
 __netif_receive_skb+0x27/0x1d0 net/core/dev.c:5481
 netif_receive_skb_internal net/core/dev.c:5586 [inline]
 netif_receive_skb+0x12d/0x710 net/core/dev.c:5645
 tun_rx_batched.isra.0+0x462/0x710 drivers/net/tun.c:1563
 tun_get_user+0x191d/0x32f0 drivers/net/tun.c:2025
 tun_chr_write_iter+0xe1/0x1e0 drivers/net/tun.c:2058
 call_write_iter include/linux/fs.h:1919 [inline]
 new_sync_write+0x42c/0x660 fs/read_write.c:518
 vfs_write+0x747/0xa70 fs/read_write.c:605
 ksys_write+0x12d/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: 0033:0x7ffbddf175ff
Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 cc fd ff ff 48
RSP: 002b:00007ffbdb4da150 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007ffbde077f60 RCX: 00007ffbddf175ff
RDX: 000000000000002a RSI: 0000000020000140 RDI: 00000000000000f0
RBP: 00007ffbdb4da1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001
R13: 00007ffdcfb31eaf R14: 00007ffbdb4da300 R15: 0000000000022000
FAULT_INJECTION: forcing a failure.
name fail_usercopy, interval 1, probability 0, space 0, times 0
CPU: 1 PID: 14975 Comm: syz-executor.7 Not tainted 5.10.202 #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_to_user+0x2e/0x180 lib/usercopy.c:36
 copy_to_user include/linux/uaccess.h:200 [inline]
 simple_read_from_buffer+0xcc/0x160 fs/libfs.c:729
 proc_fail_nth_read+0x198/0x230 fs/proc/base.c:1423
 vfs_read+0x228/0x580 fs/read_write.c:494
 ksys_read+0x12d/0x260 fs/read_write.c:634
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x62/0xc7
RIP: 0033:0x7ffbddf1769c
Code: ec 28 48 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 fc ff ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 34 44 89 c7 48 89 44 24 08 e8 2f fd ff ff 48
RSP: 002b:00007ffbdb4da170 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 000000000000002a RCX: 00007ffbddf1769c
RDX: 000000000000000f RSI: 00007ffbdb4da1e0 RDI: 0000000000000003
RBP: 00007ffbdb4da1d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffdcfb31eaf R14: 00007ffbdb4da300 R15: 0000000000022000
isofs_fill_super: get root inode failed
netlink: 64 bytes leftover after parsing attributes in process `syz-executor.2'.