Re: [PATCH v2] mm/page_alloc.c: avoid accessing uninitialized pcp page migratetype
From: Vlastimil Babka <hidden>
Date: 2021-09-02 12:09:19
Also in:
lkml
On 9/2/21 13:54, Miaohe Lin wrote:
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.
Fixes: df1acc856923 ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Mel Gorman <redacted>
Cc: <redacted>Acked-by: Vlastimil Babka <redacted>
quoted hunk ↗ jump to hunk
--- mm/page_alloc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 9c09dcb24149..a3c6acafa478 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c@@ -3420,8 +3420,10 @@ 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