================================================ WARNING: lock held when returning to user space! 4.16.0+ #3 Not tainted ------------------------------------------------ syzkaller252875/4380 is leaving the kernel with locks still held! 1 lock held by syzkaller252875/4380: #0: 000000001e13611b (&lo->lo_ctl_mutex/1){+.+.}, at: lo_ioctl+0x8d/0x1ec0 drivers/block/loop.c:1363