====================================================== WARNING: possible circular locking dependency detected 6.13.0-rc5-syzkaller-00012-g0bc21e701a6f #0 Not tainted ------------------------------------------------------ syz.8.2149/14842 is trying to acquire lock: ffffc90006bccb58 (&kvm->lock){+.+.}-{4:4}, at: kvm_arch_suspend_notifier arch/x86/kvm/x86.c:6919 [inline] ffffc90006bccb58 (&kvm->lock){+.+.}-{4:4}, at: kvm_arch_pm_notifier+0xf5/0x2b0 arch/x86/kvm/x86.c:6941 but task is already holding lock: ffffffff8dcbeb10 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust kernel/notifier.c:344 [inline] ffffffff8dcbeb10 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust+0xa9/0x170 kernel/notifier.c:333 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 ((pm_chain_head).rwsem){++++}-{4:4}: down_write+0x93/0x200 kernel/locking/rwsem.c:1577 __blocking_notifier_chain_register kernel/notifier.c:263 [inline] blocking_notifier_chain_register+0x69/0xd0 kernel/notifier.c:282 hci_register_suspend_notifier+0xcb/0x100 net/bluetooth/hci_core.c:2769 hci_register_dev+0x616/0xc60 net/bluetooth/hci_core.c:2652 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+0x7d0/0xc10 drivers/bluetooth/hci_ldisc.c:762 tty_compat_ioctl+0x381/0x4d0 drivers/tty/tty_io.c:2991 __do_compat_sys_ioctl+0x1cb/0x2c0 fs/ioctl.c:1004 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #3 (&tty->ldisc_sem){++++}-{0:0}: __ldsem_down_read_nested+0xbe/0x920 drivers/tty/tty_ldsem.c:300 tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 tty_poll+0x94/0x1d0 drivers/tty/tty_io.c:2204 vfs_poll include/linux/poll.h:84 [inline] io_file_supports_nowait io_uring/rw.c:43 [inline] io_file_supports_nowait+0x200/0x290 io_uring/rw.c:34 __io_read+0xbd2/0x1190 io_uring/rw.c:855 io_read+0x1e/0x70 io_uring/rw.c:947 io_issue_sqe+0x175/0x1360 io_uring/io_uring.c:1740 io_queue_sqe io_uring/io_uring.c:1950 [inline] io_submit_sqe io_uring/io_uring.c:2205 [inline] io_submit_sqes+0x951/0x25f0 io_uring/io_uring.c:2322 __do_sys_io_uring_enter+0xd43/0x1620 io_uring/io_uring.c:3395 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #2 (&ctx->uring_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735 io_handle_tw_list+0x27c/0x540 io_uring/io_uring.c:1054 tctx_task_work_run+0xac/0x390 io_uring/io_uring.c:1121 tctx_task_work+0x7b/0xd0 io_uring/io_uring.c:1139 task_work_run+0x14e/0x250 kernel/task_work.c:239 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+0xbe/0xf0 kernel/entry/kvm.c:47 vcpu_run+0x1393/0x4c00 arch/x86/kvm/x86.c:11267 kvm_arch_vcpu_ioctl_run+0x44a/0x1740 arch/x86/kvm/x86.c:11560 kvm_vcpu_ioctl+0x6ce/0x1520 virt/kvm/kvm_main.c:4340 kvm_vcpu_compat_ioctl+0x210/0x3f0 virt/kvm/kvm_main.c:4555 __do_compat_sys_ioctl+0x1cb/0x2c0 fs/ioctl.c:1004 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #1 (&vcpu->mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735 kvm_vm_ioctl_create_vcpu virt/kvm/kvm_main.c:4121 [inline] kvm_vm_ioctl+0x1043/0x3df0 virt/kvm/kvm_main.c:5019 kvm_vm_compat_ioctl+0x399/0x440 virt/kvm/kvm_main.c:5321 __do_compat_sys_ioctl+0x1cb/0x2c0 fs/ioctl.c:1004 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #0 (&kvm->lock){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain kernel/locking/lockdep.c:3904 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735 kvm_arch_suspend_notifier arch/x86/kvm/x86.c:6919 [inline] kvm_arch_pm_notifier+0xf5/0x2b0 arch/x86/kvm/x86.c:6941 notifier_call_chain+0xb7/0x410 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust kernel/notifier.c:345 [inline] blocking_notifier_call_chain_robust+0xc9/0x170 kernel/notifier.c:333 pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:102 snapshot_open+0x189/0x2b0 kernel/power/user.c:77 misc_open+0x35a/0x420 drivers/char/misc.c:165 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0xf59/0x1ea0 fs/open.c:945 vfs_open+0x82/0x3f0 fs/open.c:1075 do_open fs/namei.c:3828 [inline] path_openat+0x1e6a/0x2d60 fs/namei.c:3987 do_filp_open+0x20c/0x470 fs/namei.c:4014 do_sys_openat2+0x17a/0x1e0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_compat_sys_openat fs/open.c:1479 [inline] __se_compat_sys_openat fs/open.c:1477 [inline] __ia32_compat_sys_openat+0x16e/0x210 fs/open.c:1477 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e 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.8.2149/14842: #0: ffffffff8eaa1cc8 (misc_mtx){+.+.}-{4:4}, at: misc_open+0x63/0x420 drivers/char/misc.c:129 #1: ffffffff8dc80d08 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x87/0xa0 kernel/power/main.c:56 #2: ffffffff8dcbeb10 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust kernel/notifier.c:344 [inline] #2: ffffffff8dcbeb10 ((pm_chain_head).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain_robust+0xa9/0x170 kernel/notifier.c:333 stack backtrace: CPU: 0 UID: 0 PID: 14842 Comm: syz.8.2149 Not tainted 6.13.0-rc5-syzkaller-00012-g0bc21e701a6f #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x41c/0x610 kernel/locking/lockdep.c:2074 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206 check_prev_add kernel/locking/lockdep.c:3161 [inline] check_prevs_add kernel/locking/lockdep.c:3280 [inline] validate_chain kernel/locking/lockdep.c:3904 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735 kvm_arch_suspend_notifier arch/x86/kvm/x86.c:6919 [inline] kvm_arch_pm_notifier+0xf5/0x2b0 arch/x86/kvm/x86.c:6941 notifier_call_chain+0xb7/0x410 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust kernel/notifier.c:345 [inline] blocking_notifier_call_chain_robust+0xc9/0x170 kernel/notifier.c:333 pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:102 snapshot_open+0x189/0x2b0 kernel/power/user.c:77 misc_open+0x35a/0x420 drivers/char/misc.c:165 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0xf59/0x1ea0 fs/open.c:945 vfs_open+0x82/0x3f0 fs/open.c:1075 do_open fs/namei.c:3828 [inline] path_openat+0x1e6a/0x2d60 fs/namei.c:3987 do_filp_open+0x20c/0x470 fs/namei.c:4014 do_sys_openat2+0x17a/0x1e0 fs/open.c:1402 do_sys_open fs/open.c:1417 [inline] __do_compat_sys_openat fs/open.c:1479 [inline] __se_compat_sys_openat fs/open.c:1477 [inline] __ia32_compat_sys_openat+0x16e/0x210 fs/open.c:1477 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf715e579 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f512f55c EFLAGS: 00000296 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00000000ffffff9c RCX: 0000000020000000 RDX: 0000000000040000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 10 06 adc %al,(%rsi) 2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi 6: 10 07 adc %al,(%rdi) 8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi c: 10 08 adc %cl,(%rax) e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi 1e: 00 51 52 add %dl,0x52(%rcx) 21: 55 push %rbp 22: 89 e5 mov %esp,%ebp 24: 0f 34 sysenter 26: cd 80 int $0x80 * 28: 5d pop %rbp <-- trapping instruction 29: 5a pop %rdx 2a: 59 pop %rcx 2b: c3 ret 2c: 90 nop 2d: 90 nop 2e: 90 nop 2f: 90 nop 30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi