static __always_inline void __vma_unlink_common(struct mm_struct *mm,
						struct vm_area_struct *vma,
						struct vm_area_struct *prev,
						bool has_prev,
						struct vm_area_struct *ignore)
{
	struct vm_area_struct *next;

	vma_rb_erase_ignore(vma, &mm->mm_rb, ignore);
	next = vma->vm_next;
	if (has_prev)
		prev->vm_next = next;
	else {
		prev = vma->vm_prev;
		if (prev)
			prev->vm_next = next;
		else
			mm->mmap = next;
	}
	if (next)
		next->vm_prev = prev;

	/* Kill the cache */
	vmacache_invalidate(mm);
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.