INFO: task syz-executor0:2034 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D26792 2034 1 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 blkdev_reread_part+0x18/0x30 block/ioctl.c:192 loop_reread_partitions+0x72/0x80 drivers/block/loop.c:614 loop_clr_fd+0x826/0xac0 drivers/block/loop.c:1068 lo_ioctl+0x6e6/0x17d0 drivers/block/loop.c:1383 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x57d/0x18c0 block/ioctl.c:594 block_ioctl+0xd9/0x120 fs/block_dev.c:1873 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1a0/0x1030 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7e/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x456f07 RSP: 002b:00007ffd6c3d9458 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000456f07 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000003 R13: 000000000002d485 R14: 000000000000008a R15: badc0ffeebadface INFO: task syz-executor2:2037 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D27776 2037 1 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 lo_release+0x1a/0x190 drivers/block/loop.c:1635 __blkdev_put+0x526/0x6e0 fs/block_dev.c:1783 blkdev_close+0x86/0xb0 fs/block_dev.c:1855 __fput+0x25e/0x6f0 fs/file_table.c:210 task_work_run+0x116/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x12e/0x150 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+0x35d/0x4b0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x410c30 RSP: 002b:00007ffc7845bdd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000410c30 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003 RBP: 0000000000000003 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000003 R13: 000000000002d53b R14: 000000000000008a R15: badc0ffeebadface INFO: task syz-executor6:2038 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D27800 2038 1 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 lo_open+0x17/0xa0 drivers/block/loop.c:1592 __blkdev_get+0x267/0xe50 fs/block_dev.c:1467 blkdev_get+0x97/0x8c0 fs/block_dev.c:1604 blkdev_open+0x1bd/0x240 fs/block_dev.c:1762 do_dentry_open+0x426/0xda0 fs/open.c:764 vfs_open+0x11c/0x210 fs/open.c:878 do_last fs/namei.c:3408 [inline] path_openat+0x4eb/0x23a0 fs/namei.c:3550 do_filp_open+0x197/0x270 fs/namei.c:3584 do_sys_open+0x2ef/0x580 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x410db0 RSP: 002b:00007ffc108897b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000410db0 RDX: 00007ffc108897fa RSI: 0000000000000002 RDI: 00007ffc108897f0 RBP: 00000000000002c8 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000010 R13: 000000000002d47e R14: 0000000000000084 R15: badc0ffeebadface INFO: task syz-executor4:2041 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D27720 2041 1 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 blkdev_get+0x97/0x8c0 fs/block_dev.c:1604 blkdev_open+0x1bd/0x240 fs/block_dev.c:1762 do_dentry_open+0x426/0xda0 fs/open.c:764 vfs_open+0x11c/0x210 fs/open.c:878 do_last fs/namei.c:3408 [inline] path_openat+0x4eb/0x23a0 fs/namei.c:3550 do_filp_open+0x197/0x270 fs/namei.c:3584 do_sys_open+0x2ef/0x580 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x410db0 RSP: 002b:00007ffda97672f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000410db0 RDX: 00007ffda976733a RSI: 0000000000000002 RDI: 00007ffda9767330 RBP: 00000000000002e5 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 000000000000000c R13: 000000000002d57e R14: 000000000000008f R15: badc0ffeebadface INFO: task syz-executor1:2042 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D27720 2042 1 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 lo_open+0x17/0xa0 drivers/block/loop.c:1592 __blkdev_get+0x267/0xe50 fs/block_dev.c:1467 blkdev_get+0x97/0x8c0 fs/block_dev.c:1604 blkdev_open+0x1bd/0x240 fs/block_dev.c:1762 do_dentry_open+0x426/0xda0 fs/open.c:764 vfs_open+0x11c/0x210 fs/open.c:878 do_last fs/namei.c:3408 [inline] path_openat+0x4eb/0x23a0 fs/namei.c:3550 do_filp_open+0x197/0x270 fs/namei.c:3584 do_sys_open+0x2ef/0x580 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x410db0 RSP: 002b:00007ffd96d35bb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000410db0 RDX: 00007ffd96d35bfa RSI: 0000000000000002 RDI: 00007ffd96d35bf0 RBP: 00000000000002f2 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000006 R13: 000000000002e041 R14: 0000000000000095 R15: badc0ffeebadface INFO: task syz-executor5:7275 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor5 D27256 7275 1 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 lo_open+0x17/0xa0 drivers/block/loop.c:1592 __blkdev_get+0x267/0xe50 fs/block_dev.c:1467 blkdev_get+0x97/0x8c0 fs/block_dev.c:1604 blkdev_open+0x1bd/0x240 fs/block_dev.c:1762 do_dentry_open+0x426/0xda0 fs/open.c:764 vfs_open+0x11c/0x210 fs/open.c:878 do_last fs/namei.c:3408 [inline] path_openat+0x4eb/0x23a0 fs/namei.c:3550 do_filp_open+0x197/0x270 fs/namei.c:3584 do_sys_open+0x2ef/0x580 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x410db0 RSP: 002b:00007ffcdcfd0f58 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000410db0 RDX: 00007ffcdcfd0f9a RSI: 0000000000000002 RDI: 00007ffcdcfd0f90 RBP: 0000000000000272 R08: 0000000000000000 R09: 000000000000000a R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000000007 R13: 000000000002d47b R14: 0000000000000071 R15: badc0ffeebadface INFO: task syz-executor7:11772 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D28472 11772 2040 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 loop_control_ioctl+0x180/0x310 drivers/block/loop.c:1965 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1a0/0x1030 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7e/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457099 RSP: 002b:00007fed77599c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fed7759a6d4 RCX: 0000000000457099 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000004 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004cf8c8 R14: 00000000004c5b29 R15: 0000000000000000 INFO: task syz-executor7:11779 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor7 D29272 11779 2040 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1951 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1a0/0x1030 fs/ioctl.c:684 SYSC_ioctl fs/ioctl.c:701 [inline] SyS_ioctl+0x7e/0xb0 fs/ioctl.c:692 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457099 RSP: 002b:00007fed77557c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fed775586d4 RCX: 0000000000457099 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000004 RBP: 00000000009301e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004cf8c8 R14: 00000000004c5b29 R15: 0000000000000002 INFO: task blkid:11768 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28904 11768 5881 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 lo_open+0x17/0xa0 drivers/block/loop.c:1592 __blkdev_get+0x267/0xe50 fs/block_dev.c:1467 blkdev_get+0x97/0x8c0 fs/block_dev.c:1604 blkdev_open+0x1bd/0x240 fs/block_dev.c:1762 do_dentry_open+0x426/0xda0 fs/open.c:764 vfs_open+0x11c/0x210 fs/open.c:878 do_last fs/namei.c:3408 [inline] path_openat+0x4eb/0x23a0 fs/namei.c:3550 do_filp_open+0x197/0x270 fs/namei.c:3584 do_sys_open+0x2ef/0x580 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f5e2859b120 RSP: 002b:00007ffe22cb3c38 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5e2859b120 RDX: 00007ffe22cb4f34 RSI: 0000000000000000 RDI: 00007ffe22cb4f34 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001b0c030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 INFO: task blkid:11770 blocked for more than 140 seconds. Not tainted 4.14.67+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D27816 11770 7836 0x00000004 Call Trace: schedule+0x7f/0x1b0 kernel/sched/core.c:3490 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x521/0x1480 kernel/locking/mutex.c:893 lo_open+0x17/0xa0 drivers/block/loop.c:1592 __blkdev_get+0x267/0xe50 fs/block_dev.c:1467 blkdev_get+0x97/0x8c0 fs/block_dev.c:1604 blkdev_open+0x1bd/0x240 fs/block_dev.c:1762 do_dentry_open+0x426/0xda0 fs/open.c:764 vfs_open+0x11c/0x210 fs/open.c:878 do_last fs/namei.c:3408 [inline] path_openat+0x4eb/0x23a0 fs/namei.c:3550 do_filp_open+0x197/0x270 fs/namei.c:3584 do_sys_open+0x2ef/0x580 fs/open.c:1071 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f4261dd6120 RSP: 002b:00007ffc8dc3ad88 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4261dd6120 RDX: 00007ffc8dc3cf34 RSI: 0000000000000000 RDI: 00007ffc8dc3cf34 RBP: 0000000000000000 R08: 0000000000000078 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000001138030 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000005 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x74/0x20f kernel/locking/lockdep.c:4541 2 locks held by getty/1948: #0: (&tty->ldisc_sem){++++}, at: [] tty_ldisc_ref_wait+0x20/0x80 drivers/tty/tty_ldisc.c:275 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1ff/0x15e0 drivers/tty/n_tty.c:2142 2 locks held by syz-executor0/2034: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x85/0x17d0 drivers/block/loop.c:1373 #1: (&bdev->bd_mutex){+.+.}, at: [] blkdev_reread_part+0x18/0x30 block/ioctl.c:192 2 locks held by syz-executor2/2037: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_put+0xb1/0x6e0 fs/block_dev.c:1770 #1: (loop_index_mutex){+.+.}, at: [] lo_release+0x1a/0x190 drivers/block/loop.c:1635 2 locks held by syz-executor6/2038: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x17/0xa0 drivers/block/loop.c:1592 1 lock held by syz-executor4/2041: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 2 locks held by syz-executor1/2042: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x17/0xa0 drivers/block/loop.c:1592 2 locks held by syz-executor5/7275: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x17/0xa0 drivers/block/loop.c:1592 2 locks held by syz-executor7/11772: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1951 #1: (&lo->lo_ctl_mutex#2){+.+.}, at: [] loop_control_ioctl+0x180/0x310 drivers/block/loop.c:1965 1 lock held by syz-executor7/11779: #0: (loop_index_mutex){+.+.}, at: [] loop_control_ioctl+0x71/0x310 drivers/block/loop.c:1951 2 locks held by blkid/11768: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x17/0xa0 drivers/block/loop.c:1592 2 locks held by blkid/11770: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x17/0xa0 drivers/block/loop.c:1592 1 lock held by blkid/11773: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 2 locks held by blkid/11774: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x17/0xa0 drivers/block/loop.c:1592 2 locks held by syz-executor3/11782: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 #1: (loop_index_mutex){+.+.}, at: [] lo_open+0x17/0xa0 drivers/block/loop.c:1592 1 lock held by syz-executor3/11786: #0: (&bdev->bd_mutex){+.+.}, at: [] __blkdev_get+0xf3/0xe50 fs/block_dev.c:1452 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.67+ #1 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x11b lib/dump_stack.c:53 nmi_cpu_backtrace.cold.0+0x18/0x8e lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x121/0x146 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x574/0xa70 kernel/hung_task.c:252 kthread+0x348/0x420 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 0xffffffffa4440572