INFO: task syz-executor.0:25414 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28848 25414 20052 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+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_clr_fd+0x835/0xad0 /drivers/block/loop.c:1068 lo_ioctl+0x460/0x1a30 /drivers/block/loop.c:1414 INFO: task syz-executor.2:25422 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28384 25422 25077 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+0x595/0x13e0 /kernel/locking/mutex.c:893 loop_control_ioctl+0x183/0x310 /drivers/block/loop.c:1996 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 INFO: task syz-executor.2:25428 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D27760 25428 25077 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+0x595/0x13e0 /kernel/locking/mutex.c:893 loop_control_ioctl+0x71/0x310 /drivers/block/loop.c:1982 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 INFO: task syz-executor.2:25444 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D29232 25444 25077 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+0x595/0x13e0 /kernel/locking/mutex.c:893 loop_control_ioctl+0x71/0x310 /drivers/block/loop.c:1982 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 INFO: task blkid:25424 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D28480 25424 17985 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+0x595/0x13e0 /kernel/locking/mutex.c:893 lo_open+0x19/0xb0 /drivers/block/loop.c:1623 __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/0xe20 /fs/open.c:770 vfs_open+0x105/0x230 /fs/open.c:884 do_last /fs/namei.c:3455 [inline] path_openat+0xb6c/0x2be0 /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/0x520 /arch/x86/entry/common.c:292 INFO: task syz-executor.4:25447 blocked for more than 140 seconds. Not tainted 4.14.133+ #17 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D25512 25447 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+0x595/0x13e0 /kernel/locking/mutex.c:893 lo_open+0x19/0xb0 /drivers/block/loop.c:1623 __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:770 vfs_open+0x105/0x230 /fs/open.c:884 do_last /fs/namei.c:3455 [inline] path_openat+0xb6c/0x2be0 /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/0x520 /arch/x86/entry/common.c:292 Showing all locks held in the system: 1 lock held by khungtaskd/23: #0: (tasklist_lock){.+.+}, at: [<0000000092c8a96b>] debug_show_all_locks+0x7c/0x21a /kernel/locking/lockdep.c:4541 2 locks held by getty/1757: #0: (&tty->ldisc_sem){++++}, at: [<00000000092261d7>] tty_ldisc_ref_wait+0x22/0x80 /drivers/tty/tty_ldisc.c:284 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000523ceccd>] n_tty_read+0x1f7/0x1700 /drivers/tty/n_tty.c:2156 2 locks held by syz-executor.0/25414: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [<0000000048dd1c9c>] lo_ioctl+0x86/0x1a30 /drivers/block/loop.c:1404 #1: (&bdev->bd_mutex){+.+.}, at: [<000000004f443a38>] blkdev_reread_part+0x1b/0x40 /block/ioctl.c:192 2 locks held by syz-executor.2/25422: #0: (loop_index_mutex){+.+.}, at: [<0000000044ef519d>] loop_control_ioctl+0x71/0x310 /drivers/block/loop.c:1982 #1: (&lo->lo_ctl_mutex#2){+.+.}, at: [<000000007d7b3aea>] loop_control_ioctl+0x183/0x310 /drivers/block/loop.c:1996 1 lock held by syz-executor.2/25428: #0: (loop_index_mutex){+.+.}, at: [<0000000044ef519d>] loop_control_ioctl+0x71/0x310 /drivers/block/loop.c:1982 1 lock held by syz-executor.2/25444: #0: (loop_index_mutex){+.+.}, at: [<0000000044ef519d>] loop_control_ioctl+0x71/0x310 /drivers/block/loop.c:1982 2 locks held by blkid/25424: #0: (&bdev->bd_mutex){+.+.}, at: [<0000000038f63ba2>] __blkdev_get+0xf3/0xf90 /fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000a4e65c69>] lo_open+0x19/0xb0 /drivers/block/loop.c:1623 2 locks held by syz-executor.4/25447: #0: (&bdev->bd_mutex){+.+.}, at: [<0000000038f63ba2>] __blkdev_get+0xf3/0xf90 /fs/block_dev.c:1457 #1: (loop_index_mutex){+.+.}, at: [<00000000a4e65c69>] lo_open+0x19/0xb0 /drivers/block/loop.c:1623 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.133+ #17 Call Trace: __dump_stack /lib/dump_stack.c:17 [inline] dump_stack+0xca/0x134 /lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x47/0x86 /lib/nmi_backtrace.c:101 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 74 Comm: kworker/1:1H Not tainted 4.14.133+ #17 task: 00000000217bd6b6 task.stack: 00000000d901fab9 RIP: 0010:get_current /./arch/x86/include/asm/current.h:15 [inline] RIP: 0010:debug_lockdep_rcu_enabled.part.0+0xb/0x50 /kernel/rcu/update.c:300 RSP: 0018:ffff8881d5807c20 EFLAGS: 00000002 RAX: dffffc0000000000 RBX: 1ffff1103ab00f89 RCX: 1ffffffff5f02864 RDX: 0000000000000004 RSI: 1ffffffff5e95085 RDI: ffffffffaf4a8428 RBP: ffff8881ceca8808 R08: 0000000000000000 R09: fffffbfff5f4590a R10: fffffbfff5f45909 R11: ffffffffafa2c84b R12: ffffffffaf6d3ce0 R13: 0000000000000000 R14: dffffc0000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000130 CR3: 0000000015e26006 CR4: 00000000001606a0 Call Trace: trace_lock_release /./include/trace/events/lock.h:58 [inline] lock_release+0x42b/0x740 /kernel/locking/lockdep.c:4009 Code: a2 2f 00 e9 f7 fd ff ff 48 89 ef e8 b0 a2 2f 00 e9 5f fe ff ff 90 66 2e 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 53 <65> 48 8b 1c 25 c0 de 01 00 48 8d bb 2c 08 00 00 48 89 fa 48 c1