In the Linux kernel, the following vulnerability has been resolved: ext4: set goal start correctly in ext4mbnormalizerequest We need to set acgex to notify the goal start used in ext4mbfindbygoal. Set acgex instead of acfex in ext4mbnormalizerequest. Besides we should assure goal start is in range [firstdatablock, blockscount) as ext4mbinitializecontext does. [ Added a check to make sure size is less than ar->pright; otherwise we could end up passing an underflowed value of ar->pright - size to ext4getgroupnoandoffset(), which will trigger a BUGON later on. - TYT ]