void __dump_page(struct page *page, const char *reason)
{
	bool page_poisoned = PagePoisoned(page);
	int mapcount;

	/*
	 * If struct page is poisoned don't access Page*() functions as that
	 * leads to recursive loop. Page*() check for poisoned pages, and calls
	 * dump_page() when detected.
	 */
	if (page_poisoned) {
		pr_emerg("page:%px is uninitialized and poisoned", page);
		goto hex_only;
	}

	/*
	 * Avoid VM_BUG_ON() in page_mapcount().
	 * page->_mapcount space in struct page is used by sl[aou]b pages to
	 * encode own info.
	 */
	mapcount = PageSlab(page) ? 0 : page_mapcount(page);

	pr_emerg("page:%px count:%d mapcount:%d mapping:%px index:%#lx",
		  page, page_ref_count(page), mapcount,
		  page->mapping, page_to_pgoff(page));
	if (PageCompound(page))
		pr_cont(" compound_mapcount: %d", compound_mapcount(page));
	pr_cont("\n");
	BUILD_BUG_ON(ARRAY_SIZE(pageflag_names) != __NR_PAGEFLAGS + 1);

	pr_emerg("flags: %#lx(%pGp)\n", page->flags, &page->flags);

hex_only:
	print_hex_dump(KERN_ALERT, "raw: ", DUMP_PREFIX_NONE, 32,
			sizeof(unsigned long), page,
			sizeof(struct page), false);

	if (reason)
		pr_alert("page dumped because: %s\n", reason);

#ifdef CONFIG_MEMCG
	if (!page_poisoned && page->mem_cgroup)
		pr_alert("page->mem_cgroup:%px\n", page->mem_cgroup);
#endif
}

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.