The patch titled Subject: mm/page_alloc.c: avoid accessing uninitialized pcp page migratetype has been added to the -mm tree. Its filename is mm-page_allocc-avoid-accessing-uninitialized-pcp-page-migratetype.patch

This patch should soon appear at https://ozlabs.org/~akpm/mmots/broken-out/mm-page_allocc-avoid-accessing-uni... and later at https://ozlabs.org/~akpm/mmotm/broken-out/mm-page_allocc-avoid-accessing-uni...

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------------------------------------------------------ From: Miaohe Lin linmiaohe@huawei.com Subject: 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: df1acc856923 ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock") Signed-off-by: Miaohe Lin linmiaohe@huawei.com Acked-by: Mel Gorman mgorman@techsingularity.net Acked-by: Vlastimil Babka vbabka@suse.cz Reviewed-by: David Hildenbrand david@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

mm/page_alloc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/mm/page_alloc.c~mm-page_allocc-avoid-accessing-uninitialized-pcp-page-migratetype +++ a/mm/page_alloc.c @@ -3445,8 +3445,10 @@ void free_unref_page_list(struct list_he /* 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 _

Patches currently in -mm which might be from linmiaohe@huawei.com are

mm-page_allocc-avoid-accessing-uninitialized-pcp-page-migratetype.patch mm-gup-remove-set-but-unused-local-variable-major.patch mm-gup-remove-unneed-local-variable-orig_refs.patch mm-gup-remove-useless-bug_on-in-__get_user_pages.patch mm-gup-fix-potential-pgmap-refcnt-leak-in-__gup_device_huge.patch mm-gup-use-helper-page_aligned-in-populate_vma_page_range.patch shmem-remove-unneeded-variable-ret.patch shmem-remove-unneeded-header-file.patch shmem-remove-unneeded-function-forward-declaration.patch shmem-include-header-file-to-declare-swap_info.patch mm-memcg-remove-unused-functions.patch mm-memcg-save-some-atomic-ops-when-flush-is-already-true.patch mm-hwpoison-remove-unneeded-variable-unmap_success.patch mm-hwpoison-fix-potential-pte_unmap_unlock-pte-error.patch mm-hwpoison-change-argument-struct-page-hpagep-to-hpage.patch mm-hwpoison-fix-some-obsolete-comments.patch mm-vmscan-remove-the-pagedirty-check-after-madv_free-pages-are-page_ref_freezed.patch mm-vmscan-remove-misleading-setting-to-sc-priority.patch mm-vmscan-remove-unneeded-return-value-of-kswapd_run.patch mm-vmscan-add-else-to-remove-check_pending-label.patch mm-vmstat-correct-some-wrong-comments.patch mm-vmstat-simplify-the-array-size-calculation.patch mm-vmstat-remove-unneeded-return-value.patch mm-memory_hotplug-use-helper-zone_is_zone_device-to-simplify-the-code.patch mm-memory_hotplug-make-hwpoisoned-dirty-swapcache-pages-unmovable.patch mm-zsmallocc-close-race-window-between-zs_pool_dec_isolated-and-zs_unregister_migration.patch mm-zsmallocc-combine-two-atomic-ops-in-zs_pool_dec_isolated.patch