Commit 053cfda1 authored by Miaohe Lin's avatar Miaohe Lin Committed by Linus Torvalds
Browse files

mm/page_alloc.c: avoid accessing uninitialized pcp page migratetype 

If it's not prepared to free unref page, the pcp page migratetype is
unset.  Thus we will get rubbish from get_pcppage_migratetype() and
might list_del(&page->lru) again after it's already deleted from the list
leading to grumble about data corruption.

Link: https://lkml.kernel.org/r/20210902115447.57050-1-linmiaohe@huawei.com


Fixes: df1acc85 ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
Signed-off-by: default avatarMiaohe Lin <linmiaohe@huawei.com>
Acked-by: default avatarMel Gorman <mgorman@techsingularity.net>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 32d4f4b7

mm/page_alloc.c

+3 −1
Original line number Diff line number Diff line
@@ -3428,8 +3428,10 @@ void free_unref_page_list(struct list_head *list) 
	/* Prepare pages for freeing */

	list_for_each_entry_safe(page, next, list, lru) {

		pfn = page_to_pfn(page);

		if (!free_unref_page_prepare(page, pfn, 0))

		if (!free_unref_page_prepare(page, pfn, 0)) {

			list_del(&page->lru);

			continue;

		}



		/*

		 * Free isolated pages directly to the allocator, see