diff options
| author | Miaohe Lin <linmiaohe@huawei.com> | 2022-09-16 15:22:47 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-10-03 14:03:29 -0700 |
| commit | 022e7fa0f73d7c90cf3d6bea3d4e4cc5df1e1087 (patch) | |
| tree | 7ae255503bb0820614baa09c0a86a82d78bcd368 /mm/page_alloc.c | |
| parent | 5749fcc5f04cef4091dea0c2ba6b5c5f5e05a549 (diff) | |
mm/page_alloc: fix freeing static percpu memory
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@huawei.com
Fixes: 28f836b6777b ("mm/page_alloc: split per cpu page lists and zone stats")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 21261f55dab1..43114e172592 100644 --- a/mm/page_alloc.c +++ b/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; + } } } |