IPVS: stopping backup sync thread 10578 ... INFO: task syz-executor5:3892 blocked for more than 140 seconds. Not tainted 4.4.140-g789274d #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D ffff8801d8c979c8 27264 3892 1 0x20020004 ffff8801d8c979c8 0000000000000000 ffff8800aca720e0 ffffed001594e41b ffff8800aca71800 ffff8801db21fdb8 ffff8801db21fde0 ffff8801db21f4d8 ffff8801db21f4c0 ffff8801bccc0000 ffff8800aca71800 0000000000000000 Call Trace: [] schedule+0x7a/0x1b0 kernel/sched/core.c:3359 [] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3392 [] __mutex_lock_common kernel/locking/mutex.c:582 [inline] [] mutex_lock_nested+0x307/0x850 kernel/locking/mutex.c:621 [] lo_ioctl+0x8b/0x1ad0 drivers/block/loop.c:1355 [] lo_compat_ioctl+0xb2/0x140 drivers/block/loop.c:1551 [] compat_blkdev_ioctl+0x395/0x3a10 block/compat_ioctl.c:751 [] C_SYSC_ioctl fs/compat_ioctl.c:1592 [inline] [] compat_SyS_ioctl+0x484/0x2270 fs/compat_ioctl.c:1544 [] do_syscall_32_irqs_on arch/x86/entry/common.c:392 [inline] [] do_fast_syscall_32+0x326/0x8b0 arch/x86/entry/common.c:459 [] sysenter_flags_fixed+0xd/0x17 1 lock held by syz-executor5/3892: #0: (&lo->lo_ctl_mutex/1){+.+.+.}, at: [] lo_ioctl+0x8b/0x1ad0 drivers/block/loop.c:1355 Sending NMI to all CPUs: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.140-g789274d #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffffffff84417840 task.stack: ffffffff84400000 RIP: 0010:[] [] native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:49 RSP: 0018:ffffffff84407dc8 EFLAGS: 00000246 RAX: 0000000000000007 RBX: ffffffff84a06128 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffffffff8441811c RBP: ffffffff84407dc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: fffffbfff07488ec R15: ffffffff84a06128 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feda7827000 CR3: 00000000af09c000 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff84407e00 ffffffff81025cf5 ffffffff84408000 0000000000000000 0000000000000000 fffffbfff07488ec ffffffff84a06128 ffffffff84407e10 ffffffff81027240 ffffffff84407e28 ffffffff8121bc47 dffffc0000000000 Call Trace: [] arch_safe_halt arch/x86/include/asm/paravirt.h:117 [inline] [] default_idle+0x55/0x3c0 arch/x86/kernel/process.c:290 [] arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:281 [] default_idle_call+0x57/0x70 kernel/sched/idle.c:93 [] cpuidle_idle_call kernel/sched/idle.c:157 [inline] [] cpu_idle_loop kernel/sched/idle.c:253 [inline] [] cpu_startup_entry+0x6af/0x780 kernel/sched/idle.c:301 [] rest_init+0x188/0x18e init/main.c:410 [] start_kernel+0x6b3/0x6e7 init/main.c:682 [] x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:196 [] x86_64_start_kernel+0x13f/0x162 arch/x86/kernel/head64.c:185 Code: 00 00 00 00 00 55 48 89 e5 fa 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb 5d c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 fb f4 <5d> c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 f4 5d c3 66 0f 1f 84 NMI backtrace for cpu 1 CPU: 1 PID: 491 Comm: khungtaskd Not tainted 4.4.140-g789274d #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8800bad34800 task.stack: ffff8801d8dc8000 RIP: 0010:[] [] native_apic_mem_write arch/x86/include/asm/apic.h:94 [inline] RIP: 0010:[] [] __default_send_IPI_dest_field arch/x86/include/asm/ipi.h:119 [inline] RIP: 0010:[] [] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:61 [inline] RIP: 0010:[] [] flat_send_IPI_mask+0xf6/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69 RSP: 0018:ffff8801d8dcfcc8 EFLAGS: 00000046 RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000 RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300 RBP: ffff8801d8dcfcf0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246 R13: 0000000000000003 R14: 0000000000000002 R15: ffffffff8446f6e0 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb02d90b000 CR3: 00000000af09c000 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff8446f6e0 ffffffff84a19060 0000000000000007 fffffbfff0942cbc 0000000000000040 ffff8801d8dcfd10 ffffffff810b5f51 ffffffff83c0b760 0000000000000003 ffff8801d8dcfd68 ffffffff81e19103 ffffffff8140ddaf Call Trace: [] nmi_raise_cpu_backtrace+0x61/0x80 arch/x86/kernel/apic/hw_nmi.c:33 [] nmi_trigger_all_cpu_backtrace.cold.4+0x70/0xad lib/nmi_backtrace.c:85 [] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 [] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog.cold.1+0xd3/0xee kernel/hung_task.c:238 [] kthread+0x268/0x300 kernel/kthread.c:211 [] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:510 Code: b3 5f ff f6 c4 10 75 e2 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 f2 09 da 80 cf 04 41 83 fe 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 75 1a 4c 89 e7 57 9d 0f 1f 44 00 00 e8 d2