====================================================== WARNING: possible circular locking dependency detected 5.10.209 #1 Not tainted ------------------------------------------------------ syz-executor.0/12441 is trying to acquire lock: ffff8880195f4b78 ( (work_completion)(&hdev->bg_scan_update)){+.+.}-{0:0} , at: __flush_work+0xdd/0xa90 kernel/workqueue.c:3050 but task is already holding lock: __do_sys_sendmmsg net/socket.c:2547 [inline] __se_sys_sendmmsg net/socket.c:2544 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2544 ffffffff85619668 ( rfkill_global_mutex){+.+.}-{3:3} do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 , at: rfkill_fop_write+0xff/0x4b0 net/rfkill/core.c:1232 which lock already depends on the new lock. entry_SYSCALL_64_after_hwframe+0x62/0xc7 the existing dependency chain (in reverse order) is: -> #4 RIP: 0033:0x7f874c00eb19 (rfkill_global_mutex 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 ){+.+.}-{3:3}: RSP: 002b:00007f8749584188 EFLAGS: 00000246 __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 ORIG_RAX: 0000000000000133 hci_register_dev+0x42e/0xc00 net/bluetooth/hci_core.c:3773 __vhci_create_device+0x2c8/0x5c0 drivers/bluetooth/hci_vhci.c:129 RAX: ffffffffffffffda RBX: 00007f874c121f60 RCX: 00007f874c00eb19 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 RDX: 000000000000002f RSI: 0000000020004d00 RDI: 0000000000000003 worker_thread+0x61d/0x1310 kernel/workqueue.c:2428 kthread+0x38f/0x470 kernel/kthread.c:313 RBP: 00007f87495841d0 R08: 0000000000000000 R09: 0000000000000000 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:299 -> #3 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 (&data->open_mutex R13: 00007ffda033398f R14: 00007f8749584300 R15: 0000000000022000 ){+.+.}-{3:3}: FAULT_INJECTION: forcing a failure. name failslab, interval 1, probability 0, space 0, times 0 __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 CPU: 1 PID: 12426 Comm: syz-executor.1 Not tainted 5.10.209 #1 -> #1 ( Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 &hdev->req_lock){+.+.}-{3:3} Call Trace: : __mutex_lock_common kernel/locking/mutex.c:968 [inline] __mutex_lock+0x13d/0x10b0 kernel/locking/mutex.c:1109 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 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 fail_dump lib/fault-inject.c:52 [inline] should_fail.cold+0x5/0xa lib/fault-inject.c:146 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) should_failslab+0x5/0x20 mm/slab_common.c:1193 ){+.+.}-{0:0}: 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 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 skb_clone+0x14f/0x3d0 net/core/skbuff.c:1456 __flush_work+0x105/0xa90 kernel/workqueue.c:3053 __cancel_work_timer+0x368/0x4c0 kernel/workqueue.c:3144 dev_queue_xmit_nit+0x3a7/0xb00 net/core/dev.c:2343 hci_request_cancel_all+0x73/0x230 net/bluetooth/hci_request.c:3438 hci_dev_do_close+0xd9/0x1240 net/bluetooth/hci_core.c:1733 xmit_one net/core/dev.c:3595 [inline] dev_hard_start_xmit+0xab/0x6f0 net/core/dev.c:3616 hci_rfkill_set_block+0x166/0x1a0 net/bluetooth/hci_core.c:2223 rfkill_set_block+0x1fd/0x540 net/rfkill/core.c:341 __dev_queue_xmit+0x17ec/0x2710 net/core/dev.c:4183 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 neigh_connected_output+0x382/0x4d0 net/core/neighbour.c:1538 Possible unsafe locking scenario: CPU0 CPU1 neigh_output include/net/neighbour.h:509 [inline] ip6_finish_output2+0xaaf/0x1fe0 net/ipv6/ip6_output.c:145 ---- ---- lock( __ip6_finish_output.part.0+0x4f7/0xbc0 net/ipv6/ip6_output.c:216 rfkill_global_mutex); __ip6_finish_output include/linux/skbuff.h:972 [inline] ip6_finish_output net/ipv6/ip6_output.c:226 [inline] NF_HOOK_COND include/linux/netfilter.h:285 [inline] ip6_output+0x3aa/0x7e0 net/ipv6/ip6_output.c:249 lock(&data->open_mutex dst_output include/net/dst.h:436 [inline] ip6_local_out+0xb4/0x1a0 net/ipv6/output_core.c:161 ); lock( ip6_send_skb+0xb7/0x350 net/ipv6/ip6_output.c:1955 rfkill_global_mutex); udp_v6_send_skb+0x7aa/0x15b0 net/ipv6/udp.c:1256 lock((work_completion)(&hdev->bg_scan_update) udpv6_sendmsg+0x2113/0x2af0 net/ipv6/udp.c:1556 ); *** DEADLOCK *** 1 lock held by syz-executor.0/12441: #0: ffffffff85619668 ( rfkill_global_mutex){+.+.}-{3:3} , at: rfkill_fop_write+0xff/0x4b0 net/rfkill/core.c:1232 stack backtrace: inet6_sendmsg+0x105/0x140 net/ipv6/af_inet6.c:651 sock_sendmsg_nosec net/socket.c:651 [inline] __sock_sendmsg+0xf2/0x190 net/socket.c:663 ____sys_sendmsg+0x334/0x870 net/socket.c:2378 ___sys_sendmsg+0xf3/0x170 net/socket.c:2432 __sys_sendmmsg+0x195/0x470 net/socket.c:2518 __do_sys_sendmmsg net/socket.c:2547 [inline] __se_sys_sendmmsg net/socket.c:2544 [inline] __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2544 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x62/0xc7 RIP: 0033:0x7f1530032b19 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:00007f152d5a8188 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f1530145f60 RCX: 00007f1530032b19 RDX: 000000000000002f RSI: 0000000020004d00 RDI: 0000000000000003 RBP: 00007f152d5a81d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffe6c8a281f R14: 00007f152d5a8300 R15: 0000000000022000 CPU: 0 PID: 12441 Comm: syz-executor.0 Not tainted 5.10.209 #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 __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: 0033:0x7fc1fe4bcb19 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:00007fc1fba32188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc1fe5cff60 RCX: 00007fc1fe4bcb19 RDX: 0000000000000008 RSI: 00000000200000c0 RDI: 0000000000000007 RBP: 00007fc1fe516f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff8b57ba1f R14: 00007fc1fba32300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: ff c3 inc %ebx 2: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 9: 00 00 00 c: 0f 1f 40 00 nopl 0x0(%rax) 10: 48 89 f8 mov %rdi,%rax 13: 48 89 f7 mov %rsi,%rdi 16: 48 89 d6 mov %rdx,%rsi 19: 48 89 ca mov %rcx,%rdx 1c: 4d 89 c2 mov %r8,%r10 1f: 4d 89 c8 mov %r9,%r8 22: 4c 8b 4c 24 08 mov 0x8(%rsp),%r9 27: 0f 05 syscall * 29: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 2f: 73 01 jae 0x32 31: c3 retq 32: 48 c7 c1 bc ff ff ff mov $0xffffffffffffffbc,%rcx 39: f7 d8 neg %eax 3b: 64 89 01 mov %eax,%fs:(%rcx) 3e: 48 rex.W