INFO: task syz-executor.3:6952 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D24992 6952 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 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_release drivers/block/loop.c:1644 [inline] lo_release+0x84/0x1b0 drivers/block/loop.c:1668 __blkdev_put+0x436/0x7f0 fs/block_dev.c:1791 blkdev_put+0x88/0x510 fs/block_dev.c:1856 blkdev_close+0x8b/0xb0 fs/block_dev.c:1863 __fput+0x277/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x119/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x1da/0x220 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline] syscall_return_slowpath arch/x86/entry/common.c:267 [inline] do_syscall_64+0x4a9/0x630 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x412b40 RSP: 002b:00007ffebc601cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000412b40 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003 RBP: 00000000000002fc R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffebc601d00 R14: 0000000000058b9f R15: 00007ffebc601d10 INFO: task syz-executor.2:6953 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D24992 6953 6947 0x00000000 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 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_open+0x1d/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x2c9/0x1120 fs/block_dev.c:1472 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x412d20 RSP: 002b:00007fff3cea7398 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000058c95 RCX: 0000000000412d20 RDX: 00007fff3cea742a RSI: 0000000000000002 RDI: 00007fff3cea7420 RBP: 0000000000000326 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff3cea73d0 R14: 0000000000058ba2 R15: 00007fff3cea73e0 INFO: task syz-executor.0:13292 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D25232 13292 1 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 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 __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x412d20 RSP: 002b:00007ffdc87a1458 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000058c59 RCX: 0000000000412d20 RDX: 00007ffdc87a14ea RSI: 0000000000000002 RDI: 00007ffdc87a14e0 RBP: 0000000000000026 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffdc87a1490 R14: 0000000000058c3a R15: 00007ffdc87a14a0 INFO: task syz-executor.1:13699 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D29280 13699 6954 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 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 loop_control_ioctl+0x65/0x2c0 drivers/block/loop.c:1982 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x7b9/0x1070 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x458da9 RSP: 002b:00007f9084675c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458da9 RDX: 0000000000000000 RSI: 0000000000004c80 RDI: 0000000000000004 RBP: 000000000073c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f90846766d4 R13: 00000000004c20ba R14: 00000000004d4988 R15: 00000000ffffffff INFO: task syz-executor.5:13674 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28560 13674 6950 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 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 blkdev_reread_part+0x1f/0x40 block/ioctl.c:192 loop_reread_partitions+0x7c/0x90 drivers/block/loop.c:615 loop_clr_fd+0x844/0xae0 drivers/block/loop.c:1069 lo_ioctl+0x8d0/0x1c70 drivers/block/loop.c:1415 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x983/0x1880 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+0x7b9/0x1070 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x458c17 RSP: 002b:00007f9b006269f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f9b006276d4 RCX: 0000000000458c17 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000004 RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000000c R10: 0000000000000064 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 0000000000000004 R15: 00000000ffffffff INFO: task blkid:13702 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28488 13702 6913 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 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_open+0x1d/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x2c9/0x1120 fs/block_dev.c:1472 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f9097f2a120 RSP: 002b:00007fffbd91adb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9097f2a120 RDX: 00007fffbd91bf44 RSI: 0000000000000000 RDI: 00007fffbd91bf44 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001765030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 INFO: task blkid:13705 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28648 13705 6912 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 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_open+0x1d/0xb0 drivers/block/loop.c:1624 __blkdev_get+0xab1/0x1120 fs/block_dev.c:1537 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f9218684120 RSP: 002b:00007fff8d093a08 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9218684120 RDX: 00007fff8d094f41 RSI: 0000000000000000 RDI: 00007fff8d094f41 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000009ce030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 INFO: task blkid:13708 blocked for more than 140 seconds. Not tainted 4.14.113 #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D29040 13708 7074 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7be/0x1cf0 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 __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 blkdev_get+0xa8/0x8e0 fs/block_dev.c:1612 blkdev_open+0x1d1/0x260 fs/block_dev.c:1770 do_dentry_open+0x73e/0xeb0 fs/open.c:758 vfs_open+0x105/0x230 fs/open.c:872 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1065 SYSC_open fs/open.c:1083 [inline] SyS_open+0x2d/0x40 fs/open.c:1078 do_syscall_64+0x1eb/0x630 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f478614a120 RSP: 002b:00007ffc1e25be18 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f478614a120 RDX: 00007ffc1e25df34 RSI: 0000000000000000 RDI: 00007ffc1e25df34 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000cf1030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 Showing all locks held in the system: 1 lock held by khungtaskd/1008: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4544 2 locks held by getty/6904: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6905: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6906: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6907: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6908: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6909: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6910: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:377 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.3/6952: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xa6/0x7f0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [] lo_release+0x1e/0x1b0 drivers/block/loop.c:1667 #2: (loop_ctl_mutex#2){+.+.}, at: [] __lo_release drivers/block/loop.c:1644 [inline] #2: (loop_ctl_mutex#2){+.+.}, at: [] lo_release+0x84/0x1b0 drivers/block/loop.c:1668 2 locks held by syz-executor.2/6953: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x1d/0xb0 drivers/block/loop.c:1624 1 lock held by syz-executor.0/13292: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 1 lock held by syz-executor.1/13699: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x65/0x2c0 drivers/block/loop.c:1982 2 locks held by syz-executor.5/13674: #0: (loop_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1c70 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x1f/0x40 block/ioctl.c:192 2 locks held by blkid/13702: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x1d/0xb0 drivers/block/loop.c:1624 2 locks held by blkid/13705: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x1d/0xb0 drivers/block/loop.c:1624 1 lock held by blkid/13708: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0x145/0x1120 fs/block_dev.c:1457 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1008 Comm: khungtaskd Not tainted 4.14.113 #3 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+0x138/0x19c 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+0x31c/0x430 kernel/kthread.c:232 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff861b0e02