The quilt patch titled
Subject: mm/page_alloc: fix freeing static percpu memory
has been removed from the -mm tree. Its filename was
mm-page_alloc-fix-freeing-static-percpu-memory.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Subject: mm/page_alloc: fix freeing static percpu memory
Date: Fri, 16 Sep 2022 15:22:47 +0800
The size of struct per_cpu_zonestat can be 0 on !SMP && !NUMA. In that
case, zone->per_cpu_zonestats will always equal to boot_zonestats. But in
zone_pcp_reset(), zone->per_cpu_zonestats is freed via free_percpu()
directly without checking against boot_zonestats first. boot_zonestats
will be released by free_percpu() unexpectedly.
Link: https://lkml.kernel.org/r/20220916072257.9639-7-linmiaohe@xxxxxxxxxx
Fixes: 28f836b6777b ("mm/page_alloc: split per cpu page lists and zone stats")
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Oscar Salvador <osalvador@xxxxxxx>
Cc: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/page_alloc.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/mm/page_alloc.c~mm-page_alloc-fix-freeing-static-percpu-memory
+++ a/mm/page_alloc.c
@@ -9513,9 +9513,11 @@ void zone_pcp_reset(struct zone *zone)
drain_zonestat(zone, pzstats);
}
free_percpu(zone->per_cpu_pageset);
- free_percpu(zone->per_cpu_zonestats);
zone->per_cpu_pageset = &boot_pageset;
- zone->per_cpu_zonestats = &boot_zonestats;
+ if (zone->per_cpu_zonestats != &boot_zonestats) {
+ free_percpu(zone->per_cpu_zonestats);
+ zone->per_cpu_zonestats = &boot_zonestats;
+ }
}
}
_
Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are
