The function call alloc_percpu() returns a pointer to the memory address, but it hasn't been checked. Our static analysis tool indicates that null pointer dereference may exist in pointer zone->per_cpu_pageset. It is always safe to judge the null pointer before use.
Signed-off-by: Qiu-ji Chen chenqiuji666@gmail.com Cc: stable@vger.kernel.org Fixes: 9420f89db2dd ("mm: move most of core MM initialization to mm/mm_init.c") --- mm/page_alloc.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8afab64814dc..5deae1193dc3 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5703,8 +5703,14 @@ void __meminit setup_zone_pageset(struct zone *zone) /* Size may be 0 on !SMP && !NUMA */ if (sizeof(struct per_cpu_zonestat) > 0) zone->per_cpu_zonestats = alloc_percpu(struct per_cpu_zonestat); + if (!zone->per_cpu_pageset) + return;
zone->per_cpu_pageset = alloc_percpu(struct per_cpu_pages); + if (!zone->per_cpu_pageset) { + free_percpu(zone->per_cpu_pageset); + return; + } for_each_possible_cpu(cpu) { struct per_cpu_pages *pcp; struct per_cpu_zonestat *pzstats;