On 07.11.24 13:41, Qiu-ji Chen wrote:
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@xxxxxxxxx> Cc: stable@xxxxxxxxxxxxxxx Fixes: 9420f89db2dd ("mm: move most of core MM initialization to mm/mm_init.c") --- V2: Fixed the incorrect code logic. Thanks David Hildenbrand for helpful suggestion. --- mm/page_alloc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 8afab64814dc..7c8a74fd02d6 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_zonestats) + return;zone->per_cpu_pageset = alloc_percpu(struct per_cpu_pages);+ if (!zone->per_cpu_pageset) { + free_percpu(zone->per_cpu_zonestats); + return; + } for_each_possible_cpu(cpu) { struct per_cpu_pages *pcp; struct per_cpu_zonestat *pzstats;
Unmodified patch, likely not what you wanted to send? -- Cheers, David / dhildenb
