kernel: ext4: add EXT4_IGET_BAD flag to prevent unexpected bad inode

In the Linux kernel, the following vulnerability has been resolved: ext4: add EXT4IGETBAD flag to prevent unexpected bad inode There are many places that will get unhappy and crash when ext4iget returns a bad inode. However, if iget the boot loader inode, allows a bad inode to be returned, becaus...