====================================================== WARNING: possible circular locking dependency detected 6.13.0-syzkaller-09760-g69e858e0b8b2 #0 Not tainted ------------------------------------------------------ syz.4.4437/23112 is trying to acquire lock: ffffc900051beb58 (&kvm->lock){+.+.}-{4:4}, at: kvm_arch_suspend_notifier arch/x86/kvm/x86.c:6910 [inline] ffffc900051beb58 (&kvm->lock){+.+.}-{4:4}, at: kvm_arch_pm_notifier+0xda/0x370 arch/x86/kvm/x86.c:6932 but task is already holding lock: ffffffff8e80c2d0 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust+0xac/0x1e0 kernel/notifier.c:344 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 ((pm_chain_head).rwsem){++++}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 down_write+0x99/0x220 kernel/locking/rwsem.c:1577 __blocking_notifier_chain_register kernel/notifier.c:263 [inline] blocking_notifier_chain_register+0x50/0xc0 kernel/notifier.c:282 hci_register_dev+0x6f4/0x8b0 net/bluetooth/hci_core.c:2632 hci_uart_register_dev drivers/bluetooth/hci_ldisc.c:686 [inline] hci_uart_set_proto drivers/bluetooth/hci_ldisc.c:710 [inline] hci_uart_tty_ioctl+0x821/0x9e0 drivers/bluetooth/hci_ldisc.c:762 tty_ioctl+0x998/0xdc0 drivers/tty/tty_io.c:2811 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (&tty->ldisc_sem){++++}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __ldsem_down_read_nested+0xb1/0x9a0 drivers/tty/tty_ldsem.c:300 tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 tty_poll+0x6a/0x170 drivers/tty/tty_io.c:2204 vfs_poll include/linux/poll.h:82 [inline] __io_arm_poll_handler+0x34b/0x9d0 io_uring/poll.c:578 io_poll_add+0xe5/0x240 io_uring/poll.c:888 io_issue_sqe+0x37f/0x12b0 io_uring/io_uring.c:1735 io_queue_sqe io_uring/io_uring.c:1945 [inline] io_submit_sqe io_uring/io_uring.c:2200 [inline] io_submit_sqes+0xa75/0x1d60 io_uring/io_uring.c:2317 __do_sys_io_uring_enter io_uring/io_uring.c:3368 [inline] __se_sys_io_uring_enter+0x2c8/0x3390 io_uring/io_uring.c:3303 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&ctx->uring_lock){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 io_handle_tw_list+0x1b2/0x500 io_uring/io_uring.c:1054 tctx_task_work_run+0x9a/0x370 io_uring/io_uring.c:1121 tctx_task_work+0x9a/0x100 io_uring/io_uring.c:1139 task_work_run+0x24f/0x310 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] xfer_to_guest_mode_work kernel/entry/kvm.c:20 [inline] xfer_to_guest_mode_handle_work+0x88/0xd0 kernel/entry/kvm.c:47 vcpu_run+0xfb2/0x89e0 arch/x86/kvm/x86.c:11275 kvm_arch_vcpu_ioctl_run+0xa68/0x1940 arch/x86/kvm/x86.c:11572 kvm_vcpu_ioctl+0x996/0x1020 virt/kvm/kvm_main.c:4385 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&vcpu->mutex){+.+.}-{4:4}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 kvm_vm_ioctl_create_vcpu+0x55f/0x8b0 virt/kvm/kvm_main.c:4147 kvm_vm_ioctl+0x7e2/0xd30 virt/kvm/kvm_main.c:5064 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf5/0x170 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&kvm->lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 kvm_arch_suspend_notifier arch/x86/kvm/x86.c:6910 [inline] kvm_arch_pm_notifier+0xda/0x370 arch/x86/kvm/x86.c:6932 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust+0xe8/0x1e0 kernel/notifier.c:345 pm_notifier_call_chain_robust+0x2c/0x60 kernel/power/main.c:102 snapshot_open+0x19b/0x280 kernel/power/user.c:77 misc_open+0x2cc/0x340 drivers/char/misc.c:179 chrdev_open+0x521/0x600 fs/char_dev.c:414 do_dentry_open+0xdec/0x1960 fs/open.c:955 vfs_open+0x3b/0x370 fs/open.c:1085 do_open fs/namei.c:3830 [inline] path_openat+0x2c81/0x3590 fs/namei.c:3989 do_filp_open+0x27f/0x4e0 fs/namei.c:4016 do_sys_openat2+0x13e/0x1d0 fs/open.c:1427 do_sys_open fs/open.c:1442 [inline] __do_sys_openat fs/open.c:1458 [inline] __se_sys_openat fs/open.c:1453 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1453 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &kvm->lock --> &tty->ldisc_sem --> (pm_chain_head).rwsem Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock((pm_chain_head).rwsem); lock(&tty->ldisc_sem); lock((pm_chain_head).rwsem); lock(&kvm->lock); *** DEADLOCK *** 3 locks held by syz.4.4437/23112: #0: ffffffff8f17f248 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x54/0x340 drivers/char/misc.c:143 #1: ffffffff8e7eca48 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x60/0xa0 kernel/power/main.c:56 #2: ffffffff8e80c2d0 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust+0xac/0x1e0 kernel/notifier.c:344 stack backtrace: CPU: 1 UID: 0 PID: 23112 Comm: syz.4.4437 Not tainted 6.13.0-syzkaller-09760-g69e858e0b8b2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208 check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 kvm_arch_suspend_notifier arch/x86/kvm/x86.c:6910 [inline] kvm_arch_pm_notifier+0xda/0x370 arch/x86/kvm/x86.c:6932 notifier_call_chain+0x1a5/0x3f0 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust+0xe8/0x1e0 kernel/notifier.c:345 pm_notifier_call_chain_robust+0x2c/0x60 kernel/power/main.c:102 snapshot_open+0x19b/0x280 kernel/power/user.c:77 misc_open+0x2cc/0x340 drivers/char/misc.c:179 chrdev_open+0x521/0x600 fs/char_dev.c:414 do_dentry_open+0xdec/0x1960 fs/open.c:955 vfs_open+0x3b/0x370 fs/open.c:1085 do_open fs/namei.c:3830 [inline] path_openat+0x2c81/0x3590 fs/namei.c:3989 do_filp_open+0x27f/0x4e0 fs/namei.c:4016 do_sys_openat2+0x13e/0x1d0 fs/open.c:1427 do_sys_open fs/open.c:1442 [inline] __do_sys_openat fs/open.c:1458 [inline] __se_sys_openat fs/open.c:1453 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1453 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f583078cda9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f58315de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f58309a6240 RCX: 00007f583078cda9 RDX: 00000000001c5100 RSI: 00000000200002c0 RDI: ffffffffffffff9c RBP: 00007f583080e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f58309a6240 R15: 00007fff820aeb68 Bluetooth: hci0: Opcode 0x0c1a failed: -4 Bluetooth: hci0: Opcode 0x0406 failed: -4 Bluetooth: hci2: Opcode 0x0c1a failed: -4 Bluetooth: hci2: Opcode 0x0406 failed: -4 Bluetooth: hci5: Opcode 0x0c1a failed: -4 Bluetooth: hci5: Opcode 0x0406 failed: -4 Bluetooth: hci5: Opcode 0x0406 failed: -4