9pnet_virtio: no channels available for device ./file0 random: crng init done INFO: task loop0:6973 blocked for more than 120 seconds. Not tainted 4.9.90-gdd1e37e #6 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. loop0 D26832 6973 2 0x00000000 ffff8801cd84c800 0000000000000000 ffff8801cdfac540 ffff8801b14f8000 ffff8801db321b98 ffff8801cd8fed20 ffffffff838a75cb 0000000041b58ab3 ffffffff84193d90 00ffffff8123aaf0 ffff8801db322468 ffff8801db322490 Call Trace: [] schedule+0x7f/0x1b0 kernel/sched/core.c:3551 [] schedule_timeout+0x56c/0x10b0 kernel/time/timer.c:1768 [] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:5173 [] io_schedule include/linux/sched.h:460 [inline] [] bt_get.isra.8+0x2d2/0x780 block/blk-mq-tag.c:141 [] __blk_mq_get_tag block/blk-mq-tag.c:163 [inline] [] blk_mq_get_tag+0xac/0x230 block/blk-mq-tag.c:192 [] __blk_mq_alloc_request+0x27/0xab0 block/blk-mq.c:196 [] blk_mq_map_request+0x3f1/0x920 block/blk-mq.c:1207 [] blk_sq_make_request+0x1cf/0x12d0 block/blk-mq.c:1374 [] generic_make_request+0x30e/0x990 block/blk-core.c:2055 [] submit_bio+0xf6/0x4e0 block/blk-core.c:2126 [] dio_bio_submit fs/direct-io.c:420 [inline] [] do_blockdev_direct_IO+0x61b1/0x7ab0 fs/direct-io.c:1301 [] __blockdev_direct_IO+0xa5/0xd0 fs/direct-io.c:1360 [] blkdev_direct_IO+0xa0/0xd0 fs/block_dev.c:183 [] generic_file_read_iter+0x793/0x1ac0 mm/filemap.c:1952 [] blkdev_read_iter+0x105/0x170 fs/block_dev.c:1738 [] lo_rw_aio+0x4b3/0x890 drivers/block/loop.c:506 [] do_req_filebacked drivers/block/loop.c:543 [inline] [] loop_handle_cmd drivers/block/loop.c:1691 [inline] [] loop_queue_work+0x1604/0x22b0 drivers/block/loop.c:1703 [] kthread_worker_fn+0x306/0x6a0 kernel/kthread.c:627 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Showing all locks held in the system: 2 locks held by khungtaskd/516: #0: (rcu_read_lock){......}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline] #0: (rcu_read_lock){......}, at: [] watchdog+0x125/0xa70 kernel/hung_task.c:239 #1: (tasklist_lock){.+.+..}, at: [] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336 1 lock held by rsyslogd/3660: #0: (&f->f_pos_lock){+.+.+.}, at: [] __fdget_pos+0x9f/0xc0 fs/file.c:781 2 locks held by getty/3788: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+...}, at: [] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133 1 lock held by syz-executor5/7144: #0: (&lo->lo_ctl_mutex/1){+.+.+.}, at: [] lo_ioctl+0x8f/0x1990 drivers/block/loop.c:1337 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 516 Comm: khungtaskd Not tainted 4.9.90-gdd1e37e #6 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801d8667d00 ffffffff81d94ee9 0000000000000000 0000000000000000 0000000000000000 0000000000000001 ffffffff810bb920 ffff8801d8667d38 ffffffff81da000d 0000000000000000 0000000000000000 ffff8801cd84cc18 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99 [] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60 [] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x6f0/0xa70 kernel/hung_task.c:239 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff838b7116