This is a note to let you know that I've just added the patch titled
mm/page_alloc.c: avoid accessing uninitialized pcp page migratetype
to the 5.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-page_alloc.c-avoid-accessing-uninitialized-pcp-page-migratetype.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 053cfda102306a3394012f9fe2594811c34925e4 Mon Sep 17 00:00:00 2001
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Date: Wed, 8 Sep 2021 18:10:11 -0700
Subject: mm/page_alloc.c: avoid accessing uninitialized pcp page migratetype
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
commit 053cfda102306a3394012f9fe2594811c34925e4 upstream.
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@xxxxxxxxxx
Fixes: df1acc856923 ("mm/page_alloc: avoid conflating IRQs disabled with zone->lock")
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- a/mm/page_alloc.c
+++ b/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 stable-queue which might be from linmiaohe@xxxxxxxxxx are
queue-5.14/mm-page_alloc.c-avoid-accessing-uninitialized-pcp-page-migratetype.patch
