random: crng init done INFO: task syz-executor0:6540 blocked for more than 120 seconds. Not tainted 4.16.0+ #13 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D23560 6540 4521 0x80000004 Call Trace: context_switch kernel/sched/core.c:2848 [inline] __schedule+0x8fb/0x1ef0 kernel/sched/core.c:3490 schedule+0xf5/0x430 kernel/sched/core.c:3549 schedule_preempt_disabled+0x10/0x20 kernel/sched/core.c:3607 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0xb7f/0x1810 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 __blkdev_driver_ioctl block/ioctl.c:303 [inline] blkdev_ioctl+0x1759/0x1e00 block/ioctl.c:601 ioctl_by_bdev+0xa5/0x110 fs/block_dev.c:2060 isofs_get_last_session fs/isofs/inode.c:567 [inline] isofs_fill_super+0x2ba9/0x3bc0 fs/isofs/inode.c:660 mount_bdev+0x2b7/0x370 fs/super.c:1119 isofs_mount+0x34/0x40 fs/isofs/inode.c:1560 mount_fs+0x66/0x2d0 fs/super.c:1222 vfs_kern_mount.part.26+0xc6/0x4a0 fs/namespace.c:1037 vfs_kern_mount fs/namespace.c:2514 [inline] do_new_mount fs/namespace.c:2517 [inline] do_mount+0xea4/0x2b90 fs/namespace.c:2847 ksys_mount+0xab/0x120 fs/namespace.c:3063 SYSC_mount fs/namespace.c:3077 [inline] SyS_mount+0x39/0x50 fs/namespace.c:3074 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457d0a RSP: 002b:00007fb22717abb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000020000080 RCX: 0000000000457d0a RDX: 0000000020000080 RSI: 00000000200000c0 RDI: 00007fb22717ac00 RBP: 0000000000000000 R08: 00000000200008c0 R09: 0000000020000080 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000013 R13: 0000000000000668 R14: 00000000006fca60 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/878: #0: 0000000034736a5b (rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: 0000000034736a5b (rcu_read_lock){....}, at: watchdog+0x1d6/0xd70 kernel/hung_task.c:249 #1: 00000000128642ed (tasklist_lock){.+.+}, at: debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 2 locks held by getty/4445: #0: 00000000e5573ace (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000040dc05f3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4446: #0: 00000000870c0882 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000727996ed (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4447: #0: 000000008807c36a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000251f9fb1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4448: #0: 000000000e4da95e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000003de0cdba (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4449: #0: 00000000c35229fd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000fbe3d388 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4450: #0: 00000000efcd2f3b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000f554a47a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4451: #0: 00000000f79041ce (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000f2978fe4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by syz-executor0/6540: #0: 00000000566d4c39 (&type->s_umount_key#49/1){+.+.}, at: alloc_super fs/super.c:211 [inline] #0: 00000000566d4c39 (&type->s_umount_key#49/1){+.+.}, at: sget_userns+0x3b2/0xe60 fs/super.c:502 #1: 0000000043ca8836 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 1 lock held by syz-executor0/6584: #0: 000000007bf3d3f9 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x176/0x13b0 fs/block_dev.c:1458 3 locks held by syz-executor7/6541: #0: 0000000043ca8836 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 #1: 000000007bf3d3f9 (&bdev->bd_mutex){+.+.}, at: blkdev_reread_part+0x1e/0x40 block/ioctl.c:192 #2: 00000000566d4c39 (&type->s_umount_key#50){.+.+}, at: __get_super.part.10+0x1d3/0x280 fs/super.c:663 1 lock held by syz-executor7/6585: #0: 000000007bf3d3f9 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x176/0x13b0 fs/block_dev.c:1458 1 lock held by syz-executor7/6589: #0: 0000000043ca8836 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 1 lock held by syz-executor7/6590: #0: 0000000043ca8836 (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8b/0x1b70 drivers/block/loop.c:1355 1 lock held by blkid/6549: #0: 000000007bf3d3f9 (&bdev->bd_mutex){+.+.}, at: __blkdev_get+0x176/0x13b0 fs/block_dev.c:1458 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 878 Comm: khungtaskd Not tainted 4.16.0+ #13 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+0x1a7/0x27d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1e0/0x220 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x123/0x180 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:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0x969/0xd70 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.16.0+ #13 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:rcu_dynticks_eqs_exit+0x0/0x50 kernel/rcu/tree.c:294 RSP: 0018:ffff8801db007bd0 EFLAGS: 00000046 RAX: ffff8801db023608 RBX: 1ffff1003b600f81 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 1ffff1003b600f81 RDI: ffff8801db023610 RBP: ffff8801db007cb0 R08: ffffed003b6046c3 R09: ffffed003b6046c3 R10: 0000000000000001 R11: ffffed003b6046c2 R12: 1ffff1003b600f7d R13: ffff8801db023600 R14: 0000000000000001 R15: ffff8801db007c88 FS: 0000000000000000(0000) GS:ffff8801db000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000001b3119000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_irq_enter+0xd8/0x110 kernel/rcu/tree.c:1042 irq_enter+0x13/0xd0 kernel/softirq.c:339 scheduler_ipi+0x317/0xa40 kernel/sched/core.c:1768 smp_reschedule_interrupt+0xe6/0x650 arch/x86/kernel/smp.c:277 reschedule_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:886 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0018:ffffffff88407c38 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffffffff1080f8a RCX: 0000000000000000 RDX: 1ffffffff10a2558 RSI: 0000000000000001 RDI: ffffffff88512ac0 RBP: ffffffff88407c38 R08: ffffed003b6046c3 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff88407cf0 R14: ffffffff88eccfa0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline] default_idle+0xbf/0x430 arch/x86/kernel/process.c:354 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:345 default_idle_call+0x36/0x90 kernel/sched/idle.c:93 cpuidle_idle_call kernel/sched/idle.c:151 [inline] do_idle+0x24a/0x3b0 kernel/sched/idle.c:241 cpu_startup_entry+0x104/0x120 kernel/sched/idle.c:346 rest_init+0xed/0xf0 init/main.c:437 start_kernel+0x7f1/0x819 init/main.c:717 x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:443 x86_64_start_kernel+0x77/0x7a arch/x86/kernel/head64.c:424 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:242 Code: 48 c7 c3 00 36 02 00 65 48 03 1d 84 38 a3 7e 48 8d 7b 10 be 04 00 00 00 e8 2e fa 49 00 b8 02 00 00 00 f0 0f c1 43 10 5b 5d c3 90 <55> 48 89 e5 41 54 53 48 c7 c3 00 36 02 00 65 48 03 1d 52 38 a3