INFO: task syz-executor3:19283 blocked for more than 120 seconds. Not tainted 4.4.112-gd96d95d #31 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D ffff8801ce50f268 28072 19283 4889 0x00000004 ffff8801ce50f268 0000000000000000 0000000000000000 ffff8801ce50f240 ffffffff81d652eb 0000000000000000 ffff8801db21fdb8 ffff8801db21fde0 ffff8801db21f4d8 ffff8801d2170000 ffff8800b6f517c0 ffff8801ce508000 Call Trace: [] schedule+0x9a/0x1c0 kernel/sched/core.c:3351 [] schedule_timeout+0x3a1/0x970 kernel/time/timer.c:1508 [] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:4932 [] io_schedule include/linux/sched.h:447 [inline] [] bit_wait_io+0x1b/0xc0 kernel/sched/wait.c:595 [] __wait_on_bit_lock+0x8f/0x140 kernel/sched/wait.c:434 [] __lock_page+0x18d/0x1f0 mm/filemap.c:888 [] lock_page include/linux/pagemap.h:458 [inline] [] pagecache_get_page+0x316/0x3f0 mm/filemap.c:1161 [] grab_cache_page_write_begin+0x63/0x90 mm/filemap.c:2494 [] block_write_begin+0x3a/0xd0 fs/buffer.c:2038 [] blkdev_write_begin+0x3c/0x50 fs/block_dev.c:316 [] generic_perform_write+0x299/0x550 mm/filemap.c:2550 [] __generic_file_write_iter+0x35a/0x580 mm/filemap.c:2675 [] blkdev_write_iter+0x1d4/0x490 fs/block_dev.c:1655 [] vfs_iter_write+0x1c7/0x2d0 fs/read_write.c:364 [] iter_file_splice_write+0x58a/0xae0 fs/splice.c:1024 [] do_splice_from fs/splice.c:1128 [inline] [] direct_splice_actor+0x125/0x180 fs/splice.c:1294 [] splice_direct_to_actor+0x2d2/0x830 fs/splice.c:1247 [] do_splice_direct+0x1a7/0x270 fs/splice.c:1337 [] do_sendfile+0x54c/0xd30 fs/read_write.c:1227 [] SYSC_sendfile64 fs/read_write.c:1282 [inline] [] SyS_sendfile64+0xc3/0x150 fs/read_write.c:1274 [] entry_SYSCALL_64_fastpath+0x16/0x92 no locks held by syz-executor3/19283. Sending NMI to all CPUs: NMI backtrace for cpu 0 CPU: 0 PID: 485 Comm: khungtaskd Not tainted 4.4.112-gd96d95d #31 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801da3edf00 task.stack: ffff8800baca8000 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+0xf7/0x1a0 arch/x86/kernel/apic/apic_flat_64.c:69 RSP: 0018:ffff8800bacafcb8 EFLAGS: 00000046 RAX: 0000000003000000 RBX: 0000000000000c00 RCX: 0000000000000000 RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fb300 RBP: ffff8800bacafce0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000246 R13: 0000000000000003 R14: ffffffff8426ec20 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002055558 CR3: 00000001d3888000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffffffff8426ec20 ffffffff847ee640 000000000001bca0 0000000000000040 dffffc0000000000 ffff8800bacafd00 ffffffff810b99bb ffffffff839f5940 0000000000000003 ffff8800bacafd60 ffffffff81d10447 0000000000000000 Call Trace: [] nmi_raise_cpu_backtrace+0x5b/0x70 arch/x86/kernel/apic/hw_nmi.c:33 [] nmi_trigger_all_cpu_backtrace+0x4a7/0x550 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+0x6fa/0xae0 kernel/hung_task.c:238 [] kthread+0x268/0x300 kernel/kthread.c:211 [] ret_from_fork+0x3f/0x70 arch/x86/entry/entry_64.S:494 Code: b3 5f ff f6 c4 10 75 e1 44 89 e8 c1 e0 18 89 04 25 10 b3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 b3 5f ff <41> f7 c4 00 02 00 00 74 1a e8 3b 1f 17 00 4c 89 e7 57 9d 0f 1f NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.4.112-gd96d95d #31 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801da3a97c0 task.stack: ffff8801da3b8000 RIP: 0010:[] [] native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:49 RSP: 0018:ffff8801da3bfd78 EFLAGS: 00000246 RAX: 0000000000000007 RBX: ffffffff847dc748 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8801da3aa02c RBP: ffff8801da3bfd78 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c420199e80 CR3: 00000001d3888000 CR4: 0000000000160670 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff8801da3bfdb0 ffffffff81027ee5 ffff8801da3c0000 ffffffff847dc748 0000000000000000 0000000000000000 dffffc0000000000 ffff8801da3bfdc0 ffffffff8102945a ffff8801da3bfdd8 ffffffff812204d8 ffff8801da3c0000 Call Trace: [] arch_safe_halt arch/x86/include/asm/paravirt.h:117 [inline] [] default_idle+0x55/0x3c0 arch/x86/kernel/process.c:291 [] arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:282 [] default_idle_call+0x48/0x70 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+0x605/0x820 kernel/sched/idle.c:301 [] start_secondary+0x304/0x3e0 arch/x86/kernel/smpboot.c:242 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