block nbd4: Device being setup by another task block nbd4: shutting down sockets block nbd1: Receive control failed (result -107) block nbd1: shutting down sockets block nbd5: shutting down sockets INFO: task syz-executor.4:14655 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.4 D28928 14655 6352 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: 0033:0x45cb19 RSP: 002b:00007f8037e74c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000004e9b80 RCX: 000000000045cb19 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000416 R14: 00000000004c6e52 R15: 00007f8037e756d4 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 2 locks held by kworker/u5:0/1191: #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 1 lock held by in:imklog/6000: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xa6/0xc0 fs/file.c:769 1 lock held by syz-executor.1/16606: #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock_nested fs/pipe.c:67 [inline] #0: (&pipe->mutex/1){+.+.}, at: [] pipe_lock+0x58/0x70 fs/pipe.c:75 ============================================= NMI backtrace for cpu 0 CPU: 0 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3637 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: ffff8880943d0680 task.stack: ffff8880943d8000 RIP: 0010:__lock_acquire+0x1c1/0x42a0 kernel/locking/lockdep.c:3348 RSP: 0018:ffff8880943dfb00 EFLAGS: 00000086 RAX: ffffed101287bf74 RBX: ffffffff8984dd00 RCX: 1ffff1101287a1e5 RDX: 1ffff1101287a1e0 RSI: ffff8880943d0f08 RDI: ffffffff8984dd18 RBP: ffff8880943dfca8 R08: 000000000000747c R09: ffffffff89e8fd60 R10: ffff8880943d0f08 R11: ffff8880943d0680 R12: 0000000000000001 R13: dffffc0000000000 R14: ffffffff89e8fd60 R15: 643e07b86e84b7f3 FS: 00007f83b05a78c0(0000) GS:ffff8880aed00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f83ad469000 CR3: 0000000093c6b000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x170/0x3f0 kernel/locking/lockdep.c:3998 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:152 spin_lock include/linux/spinlock.h:317 [inline] cache_grow_end.part.0+0x33/0x140 mm/slab.c:2731 cache_grow_end mm/slab.c:2966 [inline] cache_alloc_refill+0x310/0x360 mm/slab.c:3052 ____cache_alloc mm/slab.c:3125 [inline] __do_cache_alloc mm/slab.c:3347 [inline] slab_alloc mm/slab.c:3382 [inline] kmem_cache_alloc+0x333/0x3c0 mm/slab.c:3550 getname_flags+0xc8/0x550 fs/namei.c:138 do_sys_open+0x202/0x3e0 fs/open.c:1075 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f83afb37840 RSP: 002b:00007fffa365cc18 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007fffa365cf20 RCX: 00007f83afb37840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 000055a7b0efe0c0 RBP: 000000000000000d R08: 000000000000c0c1 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 000055a7b0ef2060 R14: 00007fffa365cee0 R15: 000055a7b0efe110 Code: 80 00 00 00 4c 8b 5c 24 78 0f 85 a0 00 00 00 45 31 e4 48 b8 00 00 00 00 00 fc ff df 48 03 84 24 98 00 00 00 48 c7 00 00 00 00 00 <48> c7 40 08 00 00 00 00 c7 40 18 00 00 00 00 48 8d 65 d8 44 89