int anon_vma_prepare(struct vm_area_struct *vma)
{
	struct anon_vma *anon_vma = vma->anon_vma;
	struct anon_vma_chain *avc;

	might_sleep();
	if (unlikely(!anon_vma)) {
		struct mm_struct *mm = vma->vm_mm;
		struct anon_vma *allocated;

		avc = anon_vma_chain_alloc(GFP_KERNEL);
		if (!avc)
			goto out_enomem;

		anon_vma = find_mergeable_anon_vma(vma);
		allocated = NULL;
		if (!anon_vma) {
			anon_vma = anon_vma_alloc();
			if (unlikely(!anon_vma))
				goto out_enomem_free_avc;
			allocated = anon_vma;
		}

		anon_vma_lock_write(anon_vma);
		/* page_table_lock to protect against threads */
		spin_lock(&mm->page_table_lock);
		if (likely(!vma->anon_vma)) {
			vma->anon_vma = anon_vma;
			anon_vma_chain_link(vma, avc, anon_vma);
			allocated = NULL;
			avc = NULL;
		}
		spin_unlock(&mm->page_table_lock);
		anon_vma_unlock_write(anon_vma);

		if (unlikely(allocated))
			put_anon_vma(allocated);
		if (unlikely(avc))
			anon_vma_chain_free(avc);
	}
	return 0;

 out_enomem_free_avc:
	anon_vma_chain_free(avc);
 out_enomem:
	return -ENOMEM;
}

This category addresses vulnerabilities caused by flawed access control mechanisms, where incorrect permission settings allow unauthorized users to access restricted resources.