block nbd0: shutting down sockets INFO: task syz-executor744:8024 blocked for more than 140 seconds. Not tainted 4.14.217-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor744 D28216 8024 8023 0x00000004 Call Trace: context_switch kernel/sched/core.c:2808 [inline] __schedule+0x88b/0x1de0 kernel/sched/core.c:3384 schedule+0x8d/0x1b0 kernel/sched/core.c:3428 schedule_timeout+0x80a/0xe90 kernel/time/timer.c:1724 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+0x3ce/0x1310 kernel/workqueue.c:2676 nbd_start_device_ioctl drivers/block/nbd.c:1255 [inline] __nbd_ioctl drivers/block/nbd.c:1326 [inline] nbd_ioctl+0x49d/0xa80 drivers/block/nbd.c:1366 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x540/0x1830 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1893 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x75a/0xff0 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: 0033:0x444f39 RSP: 002b:00007ffdb7374f98 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444f39 RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003 RBP: 00000000006cf018 R08: 00000000004002e0 R09: 00000000004002e0 R10: 00000000004002e0 R11: 0000000000000246 R12: 0000000000402100 R13: 0000000000402190 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1531: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548 2 locks held by kworker/u5:0/1675: #0: ("knbd%d-recv"nbd->index){+.+.}, at: [] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087 #1: ((&args->work)){+.+.}, at: [] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091 1 lock held by in:imklog/7711: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0x1fb/0x2b0 fs/file.c:769 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1531 Comm: khungtaskd Not tainted 4.14.217-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+0x1b2/0x281 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x13a/0x180 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+0x5b9/0xb40 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: 4626 Comm: systemd-journal Not tainted 4.14.217-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8880a118a1c0 task.stack: ffff8880a1190000 RIP: 0010:hash_name fs/namei.c:2015 [inline] RIP: 0010:link_path_walk+0x1ea/0x10a0 fs/namei.c:2101 RSP: 0018:ffff8880a1197ae8 EFLAGS: 00000246 RAX: ffff8880b58162c0 RBX: ffff8880b58162c0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: dffffc0000000000 RBP: 0000000000000000 R08: ffffffff8b9c2788 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a1197cf8 R13: fefefefefefefeff R14: 0000000000000000 R15: ffff888094eec9e5 FS: 00007f1c166218c0(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1c139f7000 CR3: 00000000a1049000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: path_openat+0x15e/0x2970 fs/namei.c:3568 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x7f1c15bb1840 RSP: 002b:00007ffc835fb098 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007ffc835fb3a0 RCX: 00007f1c15bb1840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 00005617e738df30 RBP: 000000000000000d R08: 000000000000c0c1 R09: 00000000ffffffff R10: 0000000000000069 R11: 0000000000000246 R12: 00000000ffffffff R13: 00005617e7381040 R14: 00007ffc835fb360 R15: 00005617e738dd50 Code: fe fe fe 48 89 44 24 10 48 89 c3 eb 1e e8 0f 91 cb ff 4d 31 e6 48 83 c5 08 4c 31 f3 49 c1 c6 0c 49 01 de 48 c1 cb 13 48 8d 1c db f1 90 cb ff 48 ba 2f 2f 2f 2f 2f 2f 2f 2f 48 b8 80 80 80 80