====================================================== WARNING: possible circular locking dependency detected 5.10.223 #1 Not tainted ------------------------------------------------------ syz-executor.3/8296 is trying to acquire lock: ffff88800fc60b78 ((work_completion)(&hdev->bg_scan_update)){+.+.}-{0:0}, at: __flush_work+0xdd/0xa90 kernel/workqueue.c:3050 but task is already holding lock: ffffffff8561c5c8 (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: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:328 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:298 -> #3 (&data->open_mutex){+.+.}-{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 CPU: 1 PID: 8299 Comm: syz-executor.1 Not tainted 5.10.223 #1 hci_send_frame+0x1b9/0x320 net/bluetooth/hci_core.c:4065 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014 hci_sched_acl_pkt net/bluetooth/hci_core.c:4590 [inline] hci_sched_acl net/bluetooth/hci_core.c:4675 [inline] hci_tx_work+0x10af/0x1660 net/bluetooth/hci_core.c:4746 Call Trace: process_one_work+0x9a9/0x14b0 kernel/workqueue.c:2282 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x107/0x167 lib/dump_stack.c:118 worker_thread+0x61d/0x1310 kernel/workqueue.c:2428 fail_dump lib/fault-inject.c:52 [inline] should_fail.cold+0x5/0xa lib/fault-inject.c:146 kthread+0x38f/0x470 kernel/kthread.c:328 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:298 should_failslab+0x5/0x20 mm/slab_common.c:1193 -> #2 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 (work_completion)(&hdev->tx_work) ){+.+.}-{0:0} 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 anon_vma_chain_alloc mm/rmap.c:137 [inline] anon_vma_clone+0xdc/0x590 mm/rmap.c:283 : anon_vma_fork+0x82/0x640 mm/rmap.c:346 __flush_work+0x105/0xa90 kernel/workqueue.c:3053 hci_dev_do_close+0x131/0x1240 net/bluetooth/hci_core.c:1745 dup_mmap kernel/fork.c:552 [inline] dup_mm kernel/fork.c:1380 [inline] copy_mm kernel/fork.c:1436 [inline] copy_process+0x7218/0x7800 kernel/fork.c:2126 hci_dev_close+0x175/0x1d0 net/bluetooth/hci_core.c:1865 hci_sock_ioctl+0x288/0x980 net/bluetooth/hci_sock.c:1067 sock_do_ioctl+0xd3/0x300 net/socket.c:1066 kernel_clone+0xe7/0x980 kernel/fork.c:2506 sock_ioctl+0x3ea/0x700 net/socket.c:1206 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+0x67/0xd1 -> #1 ( __do_sys_fork+0x8a/0xc0 kernel/fork.c:2569 &hdev->req_lock ){+.+.}-{3:3} : do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 __mutex_lock_common kernel/locking/mutex.c:968 [inline] __mutex_lock+0x13d/0x10b0 kernel/locking/mutex.c:1109 entry_SYSCALL_64_after_hwframe+0x67/0xd1 hci_req_sync net/bluetooth/hci_request.c:277 [inline] bg_scan_update+0x82/0x500 net/bluetooth/hci_request.c:2897 RIP: 0033:0x7fc25cc4db19 process_one_work+0x9a9/0x14b0 kernel/workqueue.c:2282 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 worker_thread+0x61d/0x1310 kernel/workqueue.c:2428 RSP: 002b:00007fc25a1c3188 EFLAGS: 00000246 ORIG_RAX: 0000000000000039 kthread+0x38f/0x470 kernel/kthread.c:328 RAX: ffffffffffffffda RBX: 00007fc25cd60f60 RCX: 00007fc25cc4db19 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 ret_from_fork+0x22/0x30 arch/x86/entry/entry_64.S:298 RBP: 00007fc25a1c31d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 -> #0 R13: 00007fffc0013e4f R14: 00007fc25a1c3300 R15: 0000000000022000 ((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: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:3440 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/0xb10 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+0x67/0xd1 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.3/8296: #0: ffffffff8561c5c8 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0xff/0x4b0 net/rfkill/core.c:1232 stack backtrace: CPU: 0 PID: 8296 Comm: syz-executor.3 Not tainted 5.10.223 #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:3440 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/0xb10 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+0x67/0xd1 RIP: 0033:0x7fb4d2f41b19 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:00007fb4d04b7188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fb4d3054f60 RCX: 00007fb4d2f41b19 RDX: 0000000000000008 RSI: 0000000020000100 RDI: 0000000000000003 RBP: 00007fb4d2f9bf6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc87637f2f R14: 00007fb4d04b7300 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