================================================ WARNING: lock held when returning to user space! 4.14.300-syzkaller #0 Not tainted ------------------------------------------------ syz-executor.3/29605 is leaving the kernel with locks still held! 1 lock held by syz-executor.3/29605: #0: (&lo->lo_ctl_mutex/1){+.+.}, at: [] lo_ioctl+0x87/0x1cd0 drivers/block/loop.c:1419