watchdog: BUG: soft lockup - CPU#0 stuck for 143s! [syz.6.1321:3906] CPU#0 Utilization every 22s during lockup: #1: 100% system, 0% softirq, 1% hardirq, 0% idle #2: 100% system, 0% softirq, 1% hardirq, 0% idle #3: 100% system, 1% softirq, 1% hardirq, 0% idle #4: 100% system, 0% softirq, 1% hardirq, 0% idle #5: 100% system, 1% softirq, 1% hardirq, 0% idle Modules linked in: CPU: 0 UID: 0 PID: 3906 Comm: syz.6.1321 Not tainted 6.12.30-syzkaller-g2e58e85c038f #0 c5e7ad78b71ddb211d6a9cda70735ca8545dcbc5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:do_make_slave fs/pnode.c:101 [inline] RIP: 0010:change_mnt_propagation+0xff/0xb00 fs/pnode.c:128 Code: 58 e7 ff 4d 8b 2e 48 c7 c3 28 ff ff ff 4d 89 fc 4d 8d 74 24 20 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 <74> 08 4c 89 f7 e8 67 58 e7 ff 4d 39 2e 0f 84 8f 00 00 00 49 81 c4 RSP: 0018:ffffc90003d7f9c0 EFLAGS: 00000246 RAX: 1ffff11029a4051c RBX: ffffffffffffff28 RCX: dffffc0000000000 RDX: ffffc900071e3000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90003d7fa10 R08: ffff8881470af2af R09: 0000000000000000 R10: ffff8881470af2a0 R11: ffffed1028e15e56 R12: ffff88814d2028c0 R13: ffff888111114330 R14: ffff88814d2028e0 R15: ffff8881178bfc00 FS: 00007fa696b8e6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2c637b CR3: 0000000146d28000 CR4: 00000000003526b0 Call Trace: umount_tree+0xdfd/0xf70 fs/namespace.c:1807 attach_recursive_mnt+0x6df/0x21c0 fs/namespace.c:2548 graft_tree+0x157/0x1c0 fs/namespace.c:2683 do_loopback+0x364/0x4b0 fs/namespace.c:2798 path_mount+0x582/0x1050 fs/namespace.c:3840 do_mount fs/namespace.c:3859 [inline] __do_sys_mount fs/namespace.c:4069 [inline] __se_sys_mount+0x2bd/0x480 fs/namespace.c:4046 __x64_sys_mount+0xc3/0xf0 fs/namespace.c:4046 x64_sys_call+0x2021/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fa695d8e9a9 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:00007fa696b8e038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fa695fb6320 RCX: 00007fa695d8e9a9 RDX: 0000000000000000 RSI: 0000200000000080 RDI: 0000200000000240 RBP: 00007fa695e10ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000080700a R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fa695fb6320 R15: 00007fff2d91cc08 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3928 Comm: syz.5.1331 Not tainted 6.12.30-syzkaller-g2e58e85c038f #0 c5e7ad78b71ddb211d6a9cda70735ca8545dcbc5 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pv_native_safe_halt+0x17/0x20 arch/x86/kernel/paravirt.c:106 Code: cc cc cc b8 ee bb 62 8c 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 73 8c 41 00 f3 0f 1e fa 55 48 89 e5 fb f4 <5d> e9 c3 54 02 00 cc cc cc b8 00 00 00 00 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000f2f5b0 EFLAGS: 000002d3 RAX: ffffffff81435565 RBX: 0000000000000003 RCX: ffff888133503900 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000003 RBP: ffffc90000f2f5b0 R08: ffffffff8720d604 R09: 1ffffffff0e41ac0 R10: dffffc0000000000 R11: fffffbfff0e41ac1 R12: dffffc0000000000 R13: 0000000000000200 R14: 0000000000000003 R15: 1ffff920001e5eb8 FS: 000055555e5b0500(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f96cde74f98 CR3: 00000001290b8000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:112 [inline] kvm_wait+0x1ba/0x220 arch/x86/kernel/kvm.c:1064 pv_wait arch/x86/include/asm/paravirt.h:596 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:466 [inline] __pv_queued_spin_lock_slowpath+0x78d/0xcc0 kernel/locking/qspinlock.c:508 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock include/linux/spinlock.h:187 [inline] __raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline] _raw_spin_lock+0x109/0x120 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] write_seqlock include/linux/seqlock.h:876 [inline] lock_mount_hash fs/namespace.c:215 [inline] mntput_no_expire+0x147/0x6c0 fs/namespace.c:1415 mntput+0x63/0xd0 fs/namespace.c:1470 simple_release_fs+0xb4/0xe0 fs/libfs.c:1086 remove_one+0x368/0x3e0 fs/debugfs/inode.c:801 simple_recursive_removal+0x71c/0x8f0 fs/libfs.c:631 debugfs_remove+0x5a/0x80 fs/debugfs/inode.c:823 hci_release_dev+0xa6/0x1540 net/bluetooth/hci_core.c:2728 bt_host_release+0x86/0xa0 net/bluetooth/hci_sysfs.c:87 device_release+0xae/0x1e0 drivers/base/core.c:-1 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1aa/0x2a0 lib/kobject.c:737 put_device+0x23/0x40 drivers/base/core.c:3800 hci_free_dev+0x20/0x30 net/bluetooth/hci_core.c:2565 hci_uart_tty_close+0x1a4/0x230 drivers/bluetooth/hci_ldisc.c:558 tty_ldisc_close drivers/tty/tty_ldisc.c:455 [inline] tty_ldisc_kill drivers/tty/tty_ldisc.c:613 [inline] tty_ldisc_release+0x2ad/0x600 drivers/tty/tty_ldisc.c:781 tty_release_struct+0x2d/0xe0 drivers/tty/tty_io.c:1690 tty_release+0xc0a/0x1230 drivers/tty/tty_io.c:1861 __fput+0x1fb/0xa00 fs/file_table.c:431 ____fput+0x20/0x30 fs/file_table.c:459 task_work_run+0x1e3/0x250 kernel/task_work.c:240 resume_user_mode_work+0x36/0x50 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x64/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f1c76d8e9a9 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:00007ffda93e4658 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00000000000260b9 RCX: 00007f1c76d8e9a9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f1c76fb7ba0 R08: 0000000000000001 R09: 0000000aa93e494f R10: 00007f1c76c00000 R11: 0000000000000246 R12: 00007f1c76fb5fac R13: 00007f1c76fb5fa0 R14: ffffffffffffffff R15: 00007ffda93e4770