watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [syz-executor.4:13654] Modules linked in: irq event stamp: 9530 hardirqs last enabled at (9529): [] restore_regs_and_return_to_kernel+0x0/0x2a hardirqs last disabled at (9530): [] apic_timer_interrupt+0x8e/0xa0 arch/x86/entry/entry_64.S:793 softirqs last enabled at (4856): [] __do_softirq+0x68b/0x9ff kernel/softirq.c:314 softirqs last disabled at (4495): [] invoke_softirq kernel/softirq.c:368 [inline] softirqs last disabled at (4495): [] irq_exit+0x193/0x240 kernel/softirq.c:409 CPU: 0 PID: 13654 Comm: syz-executor.4 Not tainted 4.14.256-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88808d4ae140 task.stack: ffff888063d20000 RIP: 0010:__read_once_size include/linux/compiler.h:185 [inline] RIP: 0010:atomic_read arch/x86/include/asm/atomic.h:27 [inline] RIP: 0010:queued_write_lock_slowpath+0xcb/0x1d0 kernel/locking/qrwlock.c:139 RSP: 0018:ffff888063d27d10 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff10 RAX: 0000000000000101 RBX: ffffffff89dd63a8 RCX: 00000000000033b5 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff89dd63a8 RBP: ffffffff89dd63ac R08: ffffffff8b9b7868 R09: 000000000004059e R10: ffff88808d4aea18 R11: ffff88808d4ae140 R12: 0000000000000003 R13: fffffbfff13bac75 R14: 00000000000000ff R15: ffff88809c1b5050 FS: 0000555555bbc400(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f922000 CR3: 00000000b076e000 CR4: 00000000003406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: queued_write_lock include/asm-generic/qrwlock.h:134 [inline] do_raw_write_lock+0xc2/0x1d0 kernel/locking/spinlock_debug.c:203 bt_sock_unlink+0x1d/0x170 net/bluetooth/af_bluetooth.c:151 hci_sock_release+0xc1/0x4c0 net/bluetooth/hci_sock.c:855 __sock_release+0xcd/0x2b0 net/socket.c:602 sock_close+0x15/0x20 net/socket.c:1139 __fput+0x25f/0x7a0 fs/file_table.c:210 task_work_run+0x11f/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1ad/0x200 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x4a3/0x640 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7fb5d963272b RSP: 002b:00007ffc788a28f0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 00007fb5d963272b RDX: ffffffffffffffbc RSI: ffffffff8740008a RDI: 0000000000000004 RBP: 0000000000000005 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000419 R11: 0000000000000293 R12: 00007fb5d9792f60 R13: 0000000000024578 R14: 0000000000000000 R15: 0000000000024570 Code: 75 dc 49 89 dd 49 89 dc 41 be ff 00 00 00 49 c1 ed 03 41 83 e4 07 48 b8 00 00 00 00 00 fc ff df 49 01 c5 41 83 c4 03 eb 02 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 9e 00 00 00 8b 03 83 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff8723c75e ---------------- Code disassembly (best guess): 0: 75 dc jne 0xffffffde 2: 49 89 dd mov %rbx,%r13 5: 49 89 dc mov %rbx,%r12 8: 41 be ff 00 00 00 mov $0xff,%r14d e: 49 c1 ed 03 shr $0x3,%r13 12: 41 83 e4 07 and $0x7,%r12d 16: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1d: fc ff df 20: 49 01 c5 add %rax,%r13 23: 41 83 c4 03 add $0x3,%r12d 27: eb 02 jmp 0x2b 29: f3 90 pause * 2b: 41 0f b6 45 00 movzbl 0x0(%r13),%eax <-- trapping instruction 30: 41 38 c4 cmp %al,%r12b 33: 7c 08 jl 0x3d 35: 84 c0 test %al,%al 37: 0f 85 9e 00 00 00 jne 0xdb 3d: 8b 03 mov (%rbx),%eax 3f: 83 .byte 0x83