Kernel crash via unchecked inode xattrs

Improper input validation in Linux ext4 allows attackers to crash the kernel when privileged code mounts a malformed filesystem image. ext4_iget_extra_inode accepts an inode-resident extended-attribute structure without xattr_check_inode validation, so later deletion walks invalid entries and reads freed or out-of-bounds kernel memory. Reaching the flaw requires a crafted ext4 image to be mounted; the demonstrated consequence is a kernel crash during inode cleanup.