INFO: task syz-executor.3:1872 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25008 1872 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4143b0 RSP: 002b:00007ffe085d1668 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000026daa RCX: 00000000004143b0 RDX: 00007ffe085d16fa RSI: 0000000000000002 RDI: 00007ffe085d16f0 RBP: 000000000000005d R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe085d16a0 R14: 0000000000026d5c R15: 00007ffe085d16b0 INFO: task syz-executor.2:3431 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D25312 3431 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4143b0 RSP: 002b:00007ffe6e856ed8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000026fd7 RCX: 00000000004143b0 RDX: 00007ffe6e856f6a RSI: 0000000000000002 RDI: 00007ffe6e856f60 RBP: 0000000000000046 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe6e856f10 R14: 0000000000026ca4 R15: 00007ffe6e856f20 INFO: task syz-executor.4:3615 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25200 3615 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4143b0 RSP: 002b:00007ffffc5147d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000026e85 RCX: 00000000004143b0 RDX: 00007ffffc51486a RSI: 0000000000000002 RDI: 00007ffffc514860 RBP: 0000000000000053 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffffc514810 R14: 0000000000026b55 R15: 00007ffffc514820 INFO: task syz-executor.5:5150 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D25280 5150 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x267/0xf90 fs/block_dev.c:1472 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4143b0 RSP: 002b:00007ffc48da9b98 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000026d7e RCX: 00000000004143b0 RDX: 00007ffc48da9c2a RSI: 0000000000000002 RDI: 00007ffc48da9c20 RBP: 0000000000000025 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc48da9bd0 R14: 0000000000026a4c R15: 00007ffc48da9be0 INFO: task syz-executor.0:5901 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28480 5901 5161 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 lo_release+0x1b/0x1a0 drivers/block/loop.c:1667 __blkdev_put+0x518/0x6d0 fs/block_dev.c:1791 blkdev_close+0x86/0xb0 fs/block_dev.c:1863 __fput+0x25e/0x710 fs/file_table.c:210 task_work_run+0x125/0x1a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x13b/0x160 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:270 [inline] do_syscall_64+0x3a3/0x520 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4141d1 RSP: 002b:00007ffc6c8aa800 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 00000000004141d1 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000006 RBP: 0000000000000000 R08: ffffffffffffffff R09: ffffffffffffffff R10: 00007ffc6c8aa8e0 R11: 0000000000000293 R12: 000000000075c118 R13: 0000000000026d65 R14: 0000000000761968 R15: 000000000075c124 INFO: task syz-executor.0:5902 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D26080 5902 5161 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 loop_reread_partitions+0x7f/0x90 drivers/block/loop.c:614 loop_set_status+0xbff/0x11f0 drivers/block/loop.c:1183 loop_set_status64+0xa5/0x100 drivers/block/loop.c:1301 lo_ioctl+0xd1/0x1a30 drivers/block/loop.c:1431 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x8d0/0x1870 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+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a4a7 RSP: 002b:00007f04d2b659f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f04d2b666d4 RCX: 000000000045a4a7 RDX: 00007f04d2b65ab0 RSI: 0000000000004c04 RDI: 0000000000000005 RBP: 0000000000000001 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000000004 R13: 0000000000000004 R14: 0000000000000005 R15: 00000000ffffffff INFO: task syz-executor.1:5919 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D27248 5919 4180 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1997 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a639 RSP: 002b:00007fd84cd9bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a639 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000006 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd84cd9c6d4 R13: 00000000004c409c R14: 00000000004d8698 R15: 00000000ffffffff INFO: task syz-executor.1:5945 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D29920 5945 4180 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0xabe/0x1040 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a639 RSP: 002b:00007fd84cd38c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a639 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000006 RBP: 000000000075c118 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd84cd396d4 R13: 00000000004c409c R14: 00000000004d8698 R15: 00000000ffffffff INFO: task blkid:5925 blocked for more than 140 seconds. Not tainted 4.14.155-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28224 5925 3316 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x595/0x13e0 kernel/locking/mutex.c:893 __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 __blkdev_get+0x6d6/0xf90 fs/block_dev.c:1517 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xe20 fs/open.c:789 vfs_open+0x105/0x230 fs/open.c:903 do_last fs/namei.c:3539 [inline] path_openat+0xb6c/0x2be0 fs/namei.c:3681 do_filp_open+0x1a1/0x280 fs/namei.c:3715 do_sys_open+0x2ca/0x590 fs/open.c:1096 do_syscall_64+0x19b/0x520 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f3d924bf120 RSP: 002b:00007ffc6f7c2f38 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3d924bf120 RDX: 00007ffc6f7c4f25 RSI: 0000000000000000 RDI: 00007ffc6f7c4f25 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000019e3030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [<00000000090b11a1>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544 2 locks held by getty/1776: #0: (&tty->ldisc_sem){++++}, at: [<00000000b85dd114>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c975d567>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.3/1872: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000f30186bf>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000fcc3512a>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.2/3431: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000f30186bf>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000fcc3512a>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.4/3615: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000f30186bf>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000fcc3512a>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.5/5150: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000f30186bf>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000fcc3512a>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.0/5901: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000580b8689>] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [<0000000098e2b566>] lo_release+0x1b/0x1a0 drivers/block/loop.c:1667 2 locks held by syz-executor.0/5902: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<00000000896f20c3>] lo_ioctl+0x86/0x1a30 drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.}, at: [<0000000065a8a64d>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 2 locks held by syz-executor.1/5919: #0: (loop_index_mutex){+.+.}, at: [<000000005bb0ea83>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 #1: (&lo->lo_ctl_mutex#2){+.+.}, at: [<0000000083e59de0>] loop_control_ioctl+0x183/0x310 drivers/block/loop.c:1997 1 lock held by syz-executor.1/5945: #0: (loop_index_mutex){+.+.}, at: [<000000005bb0ea83>] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1983 2 locks held by blkid/5925: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000f30186bf>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (&bdev->bd_mutex/1){+.+.}, at: [<00000000f30186bf>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.155-syzkaller #0 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xe5/0x154 lib/dump_stack.c:58 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x119/0x147 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+0x629/0xbe0 kernel/hung_task.c:274 kthread+0x31f/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff874a6c73