NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 NOHZ: local_softirq_pending 08 INFO: task syz-executor.5:11811 blocked for more than 140 seconds. Not tainted 4.14.184-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28816 11811 6358 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x8a6/0x1d70 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x86c/0xe50 kernel/time/timer.c:1723 do_wait_for_common kernel/sched/completion.c:91 [inline] __wait_for_common kernel/sched/completion.c:112 [inline] wait_for_common+0x272/0x430 kernel/sched/completion.c:123 flush_workqueue+0x3d1/0x1380 kernel/workqueue.c:2676 nbd_start_device_ioctl drivers/block/nbd.c:1249 [inline] __nbd_ioctl drivers/block/nbd.c:1320 [inline] nbd_ioctl+0x4e2/0xa30 drivers/block/nbd.c:1360 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x91d/0x17c0 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xfe0 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x45cb29 RSP: 002b:00007fe99110dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e9d00 RCX: 000000000045cb29 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000417 R14: 00000000004c6e7d R15: 00007fe99110e6d4 Showing all locks held in the system: 1 lock held by khungtaskd/1057: #0: (tasklist_lock){.+.?}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 1 lock held by in:imklog/5934: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xa6/0xc0 fs/file.c:769 2 locks held by kworker/u5:1/10457: #0: ("knbd%d-recv"nbd->index){+.+.}, at: [] process_one_work+0x6d8/0x14c0 kernel/workqueue.c:2087 #1: ((&args->work)){+.+.}, at: [] process_one_work+0x70e/0x14c0 kernel/workqueue.c:2091 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1057 Comm: khungtaskd Not tainted 4.14.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x1b2/0x283 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x17f lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e2/0xb80 kernel/hung_task.c:274 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 3639 Comm: systemd-journal Not tainted 4.14.184-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff888093dfc000 task.stack: ffff888093e00000 RIP: 0010:stack_access_ok+0x98/0x130 arch/x86/kernel/unwind_orc.c:287 RSP: 0018:ffff888093e079b8 EFLAGS: 00000216 RAX: ffff888093e08000 RBX: ffff888093e00000 RCX: 1ffff110127c0f61 RDX: ffff888093e07ed8 RSI: ffff888093e07ed0 RDI: ffff888093e07b08 RBP: ffff888093e07ed0 R08: 0000000000000001 R09: 0000000000000001 R10: ffff888093e07f00 R11: 0000000000056071 R12: ffff888093e07af8 R13: dffffc0000000000 R14: ffff888093e07b48 R15: ffff888093e07af8 FS: 00007ffa841368c0(0000) GS:ffff8880aec00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffa815c7000 CR3: 00000000944a3000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: deref_stack_reg+0x56/0xc0 arch/x86/kernel/unwind_orc.c:293 unwind_next_frame+0xfb0/0x1700 arch/x86/kernel/unwind_orc.c:478 __save_stack_trace+0x6b/0xd0 arch/x86/kernel/stacktrace.c:44 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551 kmem_cache_alloc+0x124/0x3c0 mm/slab.c:3552 getname_flags+0xc8/0x550 fs/namei.c:138 user_path_at_empty+0x2a/0x50 fs/namei.c:2631 user_path_at include/linux/namei.h:57 [inline] SYSC_faccessat fs/open.c:403 [inline] SyS_faccessat+0x21b/0x680 fs/open.c:353 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7ffa833f29c7 RSP: 002b:00007ffd5cee5b68 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffd5cee8b90 RCX: 00007ffa833f29c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000557f3fe639a3 RBP: 00007ffd5cee5cb0 R08: 0000557f3fe593e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000557f418a98c0 R15: 00007ffd5cee61a0 Code: f9 48 c1 e9 03 80 3c 01 00 0f 85 86 00 00 00 48 39 eb 49 8b 44 24 10 77 19 48 39 e8 76 14 48 01 ea 48 39 d3 73 0c 48 39 d0 72 07 01 00 00 00 eb 36 49 8d 7c 24 28 48 b8 00 00 00 00 00 fc ff