* [PATCH v2] mm/page_alloc.c: avoid accessing uninitialized pcp page migratetype
@ 2021-09-02 11:54 Miaohe Lin
2021-09-02 12:09 ` Vlastimil Babka
2021-09-02 12:13 ` David Hildenbrand
0 siblings, 2 replies; 3+ messages in thread
From: Miaohe Lin @ 2021-09-02 11:54 UTC (permalink / raw)
To: akpm; +Cc: vbabka, peterz, mgorman, david, linux-mm, linux-kernel, linmiaohe
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 <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
---
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
--
2.23.0
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v2] mm/page_alloc.c: avoid accessing uninitialized pcp page migratetype
2021-09-02 11:54 [PATCH v2] mm/page_alloc.c: avoid accessing uninitialized pcp page migratetype Miaohe Lin
@ 2021-09-02 12:09 ` Vlastimil Babka
2021-09-02 12:13 ` David Hildenbrand
1 sibling, 0 replies; 3+ messages in thread
From: Vlastimil Babka @ 2021-09-02 12:09 UTC (permalink / raw)
To: Miaohe Lin, akpm; +Cc: peterz, mgorman, david, linux-mm, linux-kernel
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 <mgorman@techsingularity.net>
> Cc: <stable@vger.kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
> ---
> 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
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH v2] mm/page_alloc.c: avoid accessing uninitialized pcp page migratetype
2021-09-02 11:54 [PATCH v2] mm/page_alloc.c: avoid accessing uninitialized pcp page migratetype Miaohe Lin
2021-09-02 12:09 ` Vlastimil Babka
@ 2021-09-02 12:13 ` David Hildenbrand
1 sibling, 0 replies; 3+ messages in thread
From: David Hildenbrand @ 2021-09-02 12:13 UTC (permalink / raw)
To: Miaohe Lin, akpm; +Cc: vbabka, peterz, mgorman, linux-mm, linux-kernel
On 02.09.21 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 <mgorman@techsingularity.net>
> Cc: <stable@vger.kernel.org>
> ---
> 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
>
Reviewed-by: David Hildenbrand <david@redhat.com>
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-09-02 11:54 [PATCH v2] mm/page_alloc.c: avoid accessing uninitialized pcp page migratetype Miaohe Lin
2021-09-02 12:09 ` Vlastimil Babka
2021-09-02 12:13 ` David Hildenbrand
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