__get_user_pages_locked mm/gup.c:1289 [inline] get_user_pages_unlocked+0x18a/0x690 mm/gup.c:2029 ====================================================== WARNING: possible circular locking dependency detected 5.10.209 #1 Not tainted __gup_longterm_unlocked mm/gup.c:2678 [inline] internal_get_user_pages_fast+0x14a6/0x23a0 mm/gup.c:2766 ------------------------------------------------------ syz-executor.3/17492 is trying to acquire lock: ffff8880175d8b78 ( get_user_pages_fast+0x66/0xa0 mm/gup.c:2858 (work_completion)(&hdev->bg_scan_update)){+.+.}-{0:0} iov_iter_get_pages+0x297/0xf40 lib/iov_iter.c:1321 , at: __flush_work+0xdd/0xa90 kernel/workqueue.c:3050 but task is already holding lock: ffffffff85619668 ( rfkill_global_mutex){+.+.}-{3:3} __bio_iov_iter_get_pages block/bio.c:1021 [inline] bio_iov_iter_get_pages+0x22a/0x1200 block/bio.c:1129 , 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 iomap_dio_bio_actor+0x77a/0xef0 fs/iomap/direct-io.c:282 process_one_work+0x9a9/0x14b0 kernel/workqueue.c:2282 iomap_dio_actor+0x36f/0x560 fs/iomap/direct-io.c:389 worker_thread+0x61d/0x1310 kernel/workqueue.c:2428 kthread+0x38f/0x470 kernel/kthread.c:313 iomap_apply+0x289/0x810 fs/iomap/apply.c:84 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 __iomap_dio_rw+0x6cd/0x1110 fs/iomap/direct-io.c:517 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 ( iomap_dio_rw+0x31/0x90 fs/iomap/direct-io.c:605 (work_completion)(&hdev->tx_work) ext4_dio_read_iter fs/ext4/file.c:77 [inline] ext4_file_read_iter fs/ext4/file.c:129 [inline] ext4_file_read_iter+0x2c7/0x4c0 fs/ext4/file.c:114 ){+.+.}-{0:0} call_read_iter include/linux/fs.h:1956 [inline] new_sync_read+0x424/0x6f0 fs/read_write.c:415 : __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 vfs_read+0x457/0x580 fs/read_write.c:496 do_group_exit+0x125/0x310 kernel/exit.c:980 get_signal+0x4bc/0x22e0 kernel/signal.c:2751 ksys_read+0x12d/0x260 fs/read_write.c:634 arch_do_signal_or_restart+0x2b7/0x1990 arch/x86/kernel/signal.c:805 handle_signal_work kernel/entry/common.c:145 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x10f/0x190 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x38/0x1e0 kernel/entry/common.c:274 entry_SYSCALL_64_after_hwframe+0x62/0xc7 -> #1 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 ( entry_SYSCALL_64_after_hwframe+0x62/0xc7 &hdev->req_lock RIP: 0033:0x7fa182bc8b19 ){+.+.}-{3:3}: 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 __mutex_lock_common kernel/locking/mutex.c:968 [inline] __mutex_lock+0x13d/0x10b0 kernel/locking/mutex.c:1109 RSP: 002b:00007fa18013e188 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 hci_req_sync net/bluetooth/hci_request.c:275 [inline] bg_scan_update+0x82/0x500 net/bluetooth/hci_request.c:2895 RAX: ffffffffffffffda RBX: 00007fa182cdbf60 RCX: 00007fa182bc8b19 process_one_work+0x9a9/0x14b0 kernel/workqueue.c:2282 RDX: 00000000001b4000 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 00007fa18013e1d0 R08: 0000000000000000 R09: 0000000000000000 worker_thread+0x61d/0x1310 kernel/workqueue.c:2428 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 R13: 00007ffe5ce706cf R14: 00007fa18013e300 R15: 0000000000022000 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: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 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.3/17492: #0: ffffffff85619668 (rfkill_global_mutex){+.+.}-{3:3}, at: rfkill_fop_write+0xff/0x4b0 net/rfkill/core.c:1232 stack backtrace: CPU: 1 PID: 17492 Comm: syz-executor.3 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: 0033:0x7fc0af0f5b19 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:00007fc0ac66b188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007fc0af208f60 RCX: 00007fc0af0f5b19 RDX: 0000000000000008 RSI: 00000000200000c0 RDI: 0000000000000004 RBP: 00007fc0af14ff6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd7c7e6a2f R14: 00007fc0ac66b300 R15: 0000000000022000 9pnet: Insufficient options for proto=fd 9pnet: Insufficient options for proto=fd sr 1:0:0:0: [sr0] tag#0 unaligned transfer print_req_error: 22 callbacks suppressed blk_update_request: I/O error, dev sr0, sector 2096896 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 blk_update_request: I/O error, dev loop4, sector 2096896 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 buffer_io_error: 6 callbacks suppressed Buffer I/O error on dev loop4, logical block 2096896, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer blk_update_request: I/O error, dev sr0, sector 2096897 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 blk_update_request: I/O error, dev loop4, sector 2096897 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev loop4, logical block 2096897, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer blk_update_request: I/O error, dev sr0, sector 2096898 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 blk_update_request: I/O error, dev loop4, sector 2096898 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev loop4, logical block 2096898, async page read sr 1:0:0:0: [sr0] tag#0 unaligned transfer blk_update_request: I/O error, dev sr0, sector 2096899 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 sr 1:0:0:0: [sr0] tag#0 unaligned transfer blk_update_request: I/O error, dev sr0, sector 2096900 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 sr 1:0:0:0: [sr0] tag#0 unaligned transfer blk_update_request: I/O error, dev sr0, sector 2096901 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 sr 1:0:0:0: [sr0] tag#0 unaligned transfer blk_update_request: I/O error, dev sr0, sector 2096902 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 sr 1:0:0:0: [sr0] tag#0 unaligned transfer Buffer I/O error on dev loop4, logical block 2096899, async page read Buffer I/O error on dev loop4, logical block 2096900, async page read Buffer I/O error on dev loop4, logical block 2096901, async page read Buffer I/O error on dev loop4, logical block 2096902, async page read Buffer I/O error on dev loop4, logical block 2096903, async page read ---------------- 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