INFO: task blkid:3770 blocked for more than 140 seconds. Not tainted 4.14.141 #37 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D29040 3770 2683 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_ioctl+0x8f/0x1ce0 drivers/block/loop.c:1404 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x96b/0x1860 block/ioctl.c:594 block_ioctl+0xde/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f4bba07c347 RSP: 002b:00007ffe04c56918 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000009fc030 RCX: 00007f4bba07c347 RDX: 0000000000000000 RSI: 0000000000005331 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007f4bba32c5a0 R09: 0000000000000008 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000005 INFO: task syz-executor.2:3773 blocked for more than 140 seconds. Not tainted 4.14.141 #37 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D29184 3773 29366 0x80000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3485 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x73c/0x1470 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_ioctl+0x8f/0x1ce0 drivers/block/loop.c:1404 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x96b/0x1860 block/ioctl.c:594 ioctl_by_bdev+0xa5/0x110 fs/block_dev.c:2066 udf_get_last_session+0x87/0xe0 fs/udf/lowlevel.c:37 udf_fill_super+0x114d/0x157f fs/udf/super.c:2146 mount_bdev+0x2be/0x370 fs/super.c:1134 udf_mount+0x35/0x40 fs/udf/super.c:132 mount_fs+0x97/0x2a1 fs/super.c:1237 vfs_kern_mount.part.0+0x5e/0x3d0 fs/namespace.c:1046 vfs_kern_mount fs/namespace.c:1036 [inline] do_new_mount fs/namespace.c:2549 [inline] do_mount+0x417/0x27d0 fs/namespace.c:2879 SYSC_mount fs/namespace.c:3095 [inline] SyS_mount+0xab/0x120 fs/namespace.c:3072 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x459879 RSP: 002b:00007fe872321c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459879 RDX: 0000000020000240 RSI: 0000000020000200 RDI: 0000000020000100 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe8723226d4 R13: 00000000004c5eb7 R14: 00000000004da918 R15: 00000000ffffffff INFO: task syz-executor.4:3774 blocked for more than 140 seconds. Not tainted 4.14.141 #37 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29120 3774 29368 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline] rwsem_down_read_failed+0x1f6/0x390 kernel/locking/rwsem-xadd.c:309 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:66 [inline] down_read+0x49/0xb0 kernel/locking/rwsem.c:26 __get_super.part.0+0x1cb/0x280 fs/super.c:678 __get_super include/linux/spinlock.h:317 [inline] get_super+0x2e/0x50 fs/super.c:707 fsync_bdev+0x19/0xd0 fs/block_dev.c:495 invalidate_partition+0x36/0x60 block/genhd.c:1506 drop_partitions block/partition-generic.c:442 [inline] rescan_partitions+0xe3/0x860 block/partition-generic.c:515 __blkdev_reread_part+0x15c/0x1e0 block/ioctl.c:173 blkdev_reread_part+0x27/0x40 block/ioctl.c:193 loop_reread_partitions+0x7c/0x90 drivers/block/loop.c:614 loop_set_status+0xc25/0x11f0 drivers/block/loop.c:1183 loop_set_status64+0xa6/0xf0 drivers/block/loop.c:1301 lo_ioctl+0x5c1/0x1ce0 drivers/block/loop.c:1431 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x96b/0x1860 block/ioctl.c:594 block_ioctl+0xde/0x120 fs/block_dev.c:1881 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x7ae/0x1060 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4596e7 RSP: 002b:00007f385bb4e9f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f385bb4f6d4 RCX: 00000000004596e7 RDX: 00007f385bb4eab0 RSI: 0000000000004c04 RDI: 0000000000000004 RBP: 000000000075bf20 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000000003 R13: 0000000000000003 R14: 0000000000000004 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1013: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4541 1 lock held by rsyslogd/6731: #0: (&f->f_pos_lock){+.+.}, at: [] __fdget_pos+0xab/0xd0 fs/file.c:769 2 locks held by getty/6854: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6855: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6856: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6857: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6858: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6859: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6860: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 1 lock held by blkid/3770: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8f/0x1ce0 drivers/block/loop.c:1404 2 locks held by syz-executor.2/3773: #0: (&type->s_umount_key#85/1){+.+.}, at: [] alloc_super fs/super.c:251 [inline] #0: (&type->s_umount_key#85/1){+.+.}, at: [] sget_userns+0x551/0xc30 fs/super.c:516 #1: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8f/0x1ce0 drivers/block/loop.c:1404 3 locks held by syz-executor.4/3774: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x8f/0x1ce0 drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1f/0x40 block/ioctl.c:192 #2: (&type->s_umount_key#86){++++}, at: [] __get_super.part.0+0x1cb/0x280 fs/super.c:678 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1013 Comm: khungtaskd Not tainted 4.14.141 #37 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+0x138/0x197 lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x141/0x189 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e7/0xb90 kernel/hung_task.c:274 kthread+0x319/0x430 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 skipped: idling at pc 0xffffffff861bfd4e