INFO: task syz-executor.1:1848 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D25288 1848 1 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 __lo_release drivers/block/loop.c:1644 [inline] lo_release+0x78/0x190 drivers/block/loop.c:1668 __blkdev_put+0x518/0x6d0 fs/block_dev.c:1791 blkdev_close+0x86/0xb0 fs/block_dev.c:1863 __fput+0x25e/0x700 fs/file_table.c:210 task_work_run+0x118/0x190 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: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+0x372/0x4b0 arch/x86/entry/common.c:294 INFO: task syz-executor.2:1855 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D25640 1855 1844 0x00000000 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 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/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1077 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.3:1859 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D25160 1859 1845 0x00000000 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 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/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1077 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 INFO: task syz-executor.0:29457 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D26992 29457 1847 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 loop_reread_partitions+0x72/0x80 drivers/block/loop.c:615 loop_clr_fd+0x828/0xac0 drivers/block/loop.c:1069 lo_ioctl+0x813/0x1970 drivers/block/loop.c:1415 __blkdev_driver_ioctl block/ioctl.c:297 [inline] blkdev_ioctl+0x4d9/0x1810 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/0x4b0 arch/x86/entry/common.c:289 INFO: task blkid:29462 blocked for more than 140 seconds. Not tainted 4.14.113+ #61 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D29000 29462 32701 0x00000004 Call Trace: schedule+0x92/0x1c0 kernel/sched/core.c:3498 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3556 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893 lo_open+0x19/0xb0 drivers/block/loop.c:1624 __blkdev_get+0x963/0xf90 fs/block_dev.c:1537 blkdev_get+0x97/0x8b0 fs/block_dev.c:1612 blkdev_open+0x1cc/0x250 fs/block_dev.c:1770 do_dentry_open+0x44e/0xdf0 fs/open.c:770 vfs_open+0x105/0x230 fs/open.c:884 do_last fs/namei.c:3455 [inline] path_openat+0xb6b/0x2b70 fs/namei.c:3597 do_filp_open+0x1a1/0x280 fs/namei.c:3631 do_sys_open+0x2ca/0x590 fs/open.c:1077 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [<000000008c9e60a7>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4544 2 locks held by getty/1760: #0: (&tty->ldisc_sem){++++}, at: [<000000005cd5b7f4>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000723f4275>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156 3 locks held by syz-executor.1/1848: #0: (&bdev->bd_mutex){+.+.}, at: [<000000004f3f4d26>] __blkdev_put+0xb1/0x6d0 fs/block_dev.c:1778 #1: (loop_index_mutex){+.+.}, at: [<000000000a30dd11>] lo_release+0x19/0x190 drivers/block/loop.c:1667 #2: (loop_ctl_mutex#2){+.+.}, at: [<000000000e3137d2>] __lo_release drivers/block/loop.c:1644 [inline] #2: (loop_ctl_mutex#2){+.+.}, at: [<000000000e3137d2>] lo_release+0x78/0x190 drivers/block/loop.c:1668 2 locks held by syz-executor.2/1855: #0: (&bdev->bd_mutex){+.+.}, at: [<0000000051b71f14>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000465bd808>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.3/1859: #0: (&bdev->bd_mutex){+.+.}, at: [<0000000051b71f14>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000465bd808>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 2 locks held by syz-executor.0/29457: #0: (loop_ctl_mutex/1){+.+.}, at: [<00000000672eda58>] lo_ioctl+0x83/0x1970 drivers/block/loop.c:1405 #1: (&bdev->bd_mutex){+.+.}, at: [<000000008977945d>] blkdev_reread_part+0x1b/0x40 block/ioctl.c:192 2 locks held by blkid/29462: #0: (&bdev->bd_mutex){+.+.}, at: [<0000000051b71f14>] __blkdev_get+0xf3/0xf90 fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000465bd808>] lo_open+0x19/0xb0 drivers/block/loop.c:1624 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.113+ #61 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 16500 Comm: syz-executor.5 Not tainted 4.14.113+ #61 task: 00000000fb0f4f5b task.stack: 000000002c2733e9 RIP: 0010:__fget_light+0x2/0x1f0 fs/file.c:734 RSP: 0018:ffff8881a075fdf8 EFLAGS: 00000297 RAX: ffff8881d3914680 RBX: 554e693ed5bef743 RCX: 0000000000000007 RDX: 0000000000000000 RSI: 0000000000004000 RDI: 0000000000000004 RBP: ffff8881a075fef8 R08: 0000000000000005 R09: 0000000000000006 R10: 1ffff110340ebff9 R11: 0000000000000000 R12: 0000000000000004 R13: 00000000d5bef743 R14: 0000000000000004 R15: 00007ffffffff000 FS: 00007f709d762700(0000) GS:ffff8881dba00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f421cffd000 CR3: 00000001cab24004 CR4: 00000000001606b0 DR0: 0000000020000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: __fdget fs/file.c:752 [inline] __fdget_pos+0x18/0xc0 fs/file.c:763 fdget_pos include/linux/file.h:67 [inline] SYSC_getdents64 fs/readdir.c:311 [inline] SyS_getdents64+0x121/0x270 fs/readdir.c:296 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289 Code: ff e9 aa fe ff ff e8 0e 08 f7 ff e9 c1 fd ff ff 4c 89 e7 e8 f1 07 f7 ff e9 fe fd ff ff 66 90 66 2e 0f 1f 84 00 00 00 00 00 41 55 <41> 89 f5 41 54 55 89 fd 53 e8 50 be d4 ff 48 b8 00 00 00 00 00